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/*
* linux/drivers/ide/ide-tape.c Version 1.19 Nov, 2003
*
* Copyright (C) 1995 - 1999 Gadi Oxman <gadio@netvision.net.il>
*
* $Header$
*
* This driver was constructed as a student project in the software laboratory
* of the faculty of electrical engineering in the Technion - Israel's
* Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
*
* It is hereby placed under the terms of the GNU general public license.
* (See linux/COPYING).
*/
/*
* IDE ATAPI streaming tape driver.
*
* This driver is a part of the Linux ide driver and works in co-operation
* with linux/drivers/block/ide.c.
*
* The driver, in co-operation with ide.c, basically traverses the
* request-list for the block device interface. The character device
* interface, on the other hand, creates new requests, adds them
* to the request-list of the block device, and waits for their completion.
*
* Pipelined operation mode is now supported on both reads and writes.
*
* The block device major and minor numbers are determined from the
* tape's relative position in the ide interfaces, as explained in ide.c.
*
* The character device interface consists of the following devices:
*
* ht0 major 37, minor 0 first IDE tape, rewind on close.
* ht1 major 37, minor 1 second IDE tape, rewind on close.
* ...
* nht0 major 37, minor 128 first IDE tape, no rewind on close.
* nht1 major 37, minor 129 second IDE tape, no rewind on close.
* ...
*
* Run linux/scripts/MAKEDEV.ide to create the above entries.
*
* The general magnetic tape commands compatible interface, as defined by
* include/linux/mtio.h, is accessible through the character device.
*
* General ide driver configuration options, such as the interrupt-unmask
* flag, can be configured by issuing an ioctl to the block device interface,
* as any other ide device.
*
* Our own ide-tape ioctl's can be issued to either the block device or
* the character device interface.
*
* Maximal throughput with minimal bus load will usually be achieved in the
* following scenario:
*
* 1. ide-tape is operating in the pipelined operation mode.
* 2. No buffering is performed by the user backup program.
*
* Testing was done with a 2 GB CONNER CTMA 4000 IDE ATAPI Streaming Tape Drive.
*
* Ver 0.1 Nov 1 95 Pre-working code :-)
* Ver 0.2 Nov 23 95 A short backup (few megabytes) and restore procedure
* was successful ! (Using tar cvf ... on the block
* device interface).
* A longer backup resulted in major swapping, bad
* overall Linux performance and eventually failed as
* we received non serial read-ahead requests from the
* buffer cache.
* Ver 0.3 Nov 28 95 Long backups are now possible, thanks to the
* character device interface. Linux's responsiveness
* and performance doesn't seem to be much affected
* from the background backup procedure.
* Some general mtio.h magnetic tape operations are
* now supported by our character device. As a result,
* popular tape utilities are starting to work with
* ide tapes :-)
* The following configurations were tested:
* 1. An IDE ATAPI TAPE shares the same interface
* and irq with an IDE ATAPI CDROM.
* 2. An IDE ATAPI TAPE shares the same interface
* and irq with a normal IDE disk.
* Both configurations seemed to work just fine !
* However, to be on the safe side, it is meanwhile
* recommended to give the IDE TAPE its own interface
* and irq.
* The one thing which needs to be done here is to
* add a "request postpone" feature to ide.c,
* so that we won't have to wait for the tape to finish
* performing a long media access (DSC) request (such
* as a rewind) before we can access the other device
* on the same interface. This effect doesn't disturb
* normal operation most of the time because read/write
* requests are relatively fast, and once we are
* performing one tape r/w request, a lot of requests
* from the other device can be queued and ide.c will
* service all of them after this single tape request.
* Ver 1.0 Dec 11 95 Integrated into Linux 1.3.46 development tree.
* On each read / write request, we now ask the drive
* if we can transfer a constant number of bytes
* (a parameter of the drive) only to its buffers,
* without causing actual media access. If we can't,
* we just wait until we can by polling the DSC bit.
* This ensures that while we are not transferring
* more bytes than the constant referred to above, the
* interrupt latency will not become too high and
* we won't cause an interrupt timeout, as happened
* occasionally in the previous version.
* While polling for DSC, the current request is
* postponed and ide.c is free to handle requests from
* the other device. This is handled transparently to
* ide.c. The hwgroup locking method which was used
* in the previous version was removed.
* Use of new general features which are provided by
* ide.c for use with atapi devices.
* (Programming done by Mark Lord)
* Few potential bug fixes (Again, suggested by Mark)
* Single character device data transfers are now
* not limited in size, as they were before.
* We are asking the tape about its recommended
* transfer unit and send a larger data transfer
* as several transfers of the above size.
* For best results, use an integral number of this
* basic unit (which is shown during driver
* initialization). I will soon add an ioctl to get
* this important parameter.
* Our data transfer buffer is allocated on startup,
* rather than before each data transfer. This should
* ensure that we will indeed have a data buffer.
* Ver 1.1 Dec 14 95 Fixed random problems which occurred when the tape
* shared an interface with another device.
* (poll_for_dsc was a complete mess).
* Removed some old (non-active) code which had
* to do with supporting buffer cache originated
* requests.
* The block device interface can now be opened, so
* that general ide driver features like the unmask
* interrupts flag can be selected with an ioctl.
* This is the only use of the block device interface.
* New fast pipelined operation mode (currently only on
* writes). When using the pipelined mode, the
* throughput can potentially reach the maximum
* tape supported throughput, regardless of the
* user backup program. On my tape drive, it sometimes
* boosted performance by a factor of 2. Pipelined
* mode is enabled by default, but since it has a few
* downfalls as well, you may want to disable it.
* A short explanation of the pipelined operation mode
* is available below.
* Ver 1.2 Jan 1 96 Eliminated pipelined mode race condition.
* Added pipeline read mode. As a result, restores
* are now as fast as backups.
* Optimized shared interface behavior. The new behavior
* typically results in better IDE bus efficiency and
* higher tape throughput.
* Pre-calculation of the expected read/write request
* service time, based on the tape's parameters. In
* the pipelined operation mode, this allows us to
* adjust our polling frequency to a much lower value,
* and thus to dramatically reduce our load on Linux,
* without any decrease in performance.
* Implemented additional mtio.h operations.
* The recommended user block size is returned by
* the MTIOCGET ioctl.
* Additional minor changes.
* Ver 1.3 Feb 9 96 Fixed pipelined read mode bug which prevented the
* use of some block sizes during a restore procedure.
* The character device interface will now present a
* continuous view of the media - any mix of block sizes
* during a backup/restore procedure is supported. The
* driver will buffer the requests internally and
* convert them to the tape's recommended transfer
* unit, making performance almost independent of the
* chosen user block size.
* Some improvements in error recovery.
* By cooperating with ide-dma.c, bus mastering DMA can
* now sometimes be used with IDE tape drives as well.
* Bus mastering DMA has the potential to dramatically
* reduce the CPU's overhead when accessing the device,
* and can be enabled by using hdparm -d1 on the tape's
* block device interface. For more info, read the
* comments in ide-dma.c.
* Ver 1.4 Mar 13 96 Fixed serialize support.
* Ver 1.5 Apr 12 96 Fixed shared interface operation, broken in 1.3.85.
* Fixed pipelined read mode inefficiency.
* Fixed nasty null dereferencing bug.
* Ver 1.6 Aug 16 96 Fixed FPU usage in the driver.
* Fixed end of media bug.
* Ver 1.7 Sep 10 96 Minor changes for the CONNER CTT8000-A model.
* Ver 1.8 Sep 26 96 Attempt to find a better balance between good
* interactive response and high system throughput.
* Ver 1.9 Nov 5 96 Automatically cross encountered filemarks rather
* than requiring an explicit FSF command.
* Abort pending requests at end of media.
* MTTELL was sometimes returning incorrect results.
* Return the real block size in the MTIOCGET ioctl.
* Some error recovery bug fixes.
* Ver 1.10 Nov 5 96 Major reorganization.
* Reduced CPU overhead a bit by eliminating internal
* bounce buffers.
* Added module support.
* Added multiple tape drives support.
* Added partition support.
* Rewrote DSC handling.
* Some portability fixes.
* Removed ide-tape.h.
* Additional minor changes.
* Ver 1.11 Dec 2 96 Bug fix in previous DSC timeout handling.
* Use ide_stall_queue() for DSC overlap.
* Use the maximum speed rather than the current speed
* to compute the request service time.
* Ver 1.12 Dec 7 97 Fix random memory overwriting and/or last block data
* corruption, which could occur if the total number
* of bytes written to the tape was not an integral
* number of tape blocks.
* Add support for INTERRUPT DRQ devices.
* Ver 1.13 Jan 2 98 Add "speed == 0" work-around for HP COLORADO 5GB
* Ver 1.14 Dec 30 98 Partial fixes for the Sony/AIWA tape drives.
* Replace cli()/sti() with hwgroup spinlocks.
* Ver 1.15 Mar 25 99 Fix SMP race condition by replacing hwgroup
* spinlock with private per-tape spinlock.
* Ver 1.16 Sep 1 99 Add OnStream tape support.
* Abort read pipeline on EOD.
* Wait for the tape to become ready in case it returns
* "in the process of becoming ready" on open().
* Fix zero padding of the last written block in
* case the tape block size is larger than PAGE_SIZE.
* Decrease the default disconnection time to tn.
* Ver 1.16e Oct 3 99 Minor fixes.
* Ver 1.16e1 Oct 13 99 Patches by Arnold Niessen,
* niessen@iae.nl / arnold.niessen@philips.com
* GO-1) Undefined code in idetape_read_position
* according to Gadi's email
* AJN-1) Minor fix asc == 11 should be asc == 0x11
* in idetape_issue_packet_command (did effect
* debugging output only)
* AJN-2) Added more debugging output, and
* added ide-tape: where missing. I would also
* like to add tape->name where possible
* AJN-3) Added different debug_level's
* via /proc/ide/hdc/settings
* "debug_level" determines amount of debugging output;
* can be changed using /proc/ide/hdx/settings
* 0 : almost no debugging output
* 1 : 0+output errors only
* 2 : 1+output all sensekey/asc
* 3 : 2+follow all chrdev related procedures
* 4 : 3+follow all procedures
* 5 : 4+include pc_stack rq_stack info
* 6 : 5+USE_COUNT updates
* AJN-4) Fixed timeout for retension in idetape_queue_pc_tail
* from 5 to 10 minutes
* AJN-5) Changed maximum number of blocks to skip when
* reading tapes with multiple consecutive write
* errors from 100 to 1000 in idetape_get_logical_blk
* Proposed changes to code:
* 1) output "logical_blk_num" via /proc
* 2) output "current_operation" via /proc
* 3) Either solve or document the fact that `mt rewind' is
* required after reading from /dev/nhtx to be
* able to rmmod the idetape module;
* Also, sometimes an application finishes but the
* device remains `busy' for some time. Same cause ?
* Proposed changes to release-notes:
* 4) write a simple `quickstart' section in the
* release notes; I volunteer if you don't want to
* 5) include a pointer to video4linux in the doc
* to stimulate video applications
* 6) release notes lines 331 and 362: explain what happens
* if the application data rate is higher than 1100 KB/s;
* similar approach to lower-than-500 kB/s ?
* 7) 6.6 Comparison; wouldn't it be better to allow different
* strategies for read and write ?
* Wouldn't it be better to control the tape buffer
* contents instead of the bandwidth ?
* 8) line 536: replace will by would (if I understand
* this section correctly, a hypothetical and unwanted situation
* is being described)
* Ver 1.16f Dec 15 99 Change place of the secondary OnStream header frames.
* Ver 1.17 Nov 2000 / Jan 2001 Marcel Mol, marcel@mesa.nl
* - Add idetape_onstream_mode_sense_tape_parameter_page
* function to get tape capacity in frames: tape->capacity.
* - Add support for DI-50 drives( or any DI- drive).
* - 'workaround' for read error/blank block around block 3000.
* - Implement Early warning for end of media for Onstream.
* - Cosmetic code changes for readability.
* - Idetape_position_tape should not use SKIP bit during
* Onstream read recovery.
* - Add capacity, logical_blk_num and first/last_frame_position
* to /proc/ide/hd?/settings.
* - Module use count was gone in the Linux 2.4 driver.
* Ver 1.17a Apr 2001 Willem Riede osst@riede.org
* - Get drive's actual block size from mode sense block descriptor
* - Limit size of pipeline
* Ver 1.17b Oct 2002 Alan Stern <stern@rowland.harvard.edu>
* Changed IDETAPE_MIN_PIPELINE_STAGES to 1 and actually used
* it in the code!
* Actually removed aborted stages in idetape_abort_pipeline
* instead of just changing the command code.
* Made the transfer byte count for Request Sense equal to the
* actual length of the data transfer.
* Changed handling of partial data transfers: they do not
* cause DMA errors.
* Moved initiation of DMA transfers to the correct place.
* Removed reference to unallocated memory.
* Made __idetape_discard_read_pipeline return the number of
* sectors skipped, not the number of stages.
* Replaced errant kfree() calls with __idetape_kfree_stage().
* Fixed off-by-one error in testing the pipeline length.
* Fixed handling of filemarks in the read pipeline.
* Small code optimization for MTBSF and MTBSFM ioctls.
* Don't try to unlock the door during device close if is
* already unlocked!
* Cosmetic fixes to miscellaneous debugging output messages.
* Set the minimum /proc/ide/hd?/settings values for "pipeline",
* "pipeline_min", and "pipeline_max" to 1.
*
* Here are some words from the first releases of hd.c, which are quoted
* in ide.c and apply here as well:
*
* | Special care is recommended. Have Fun!
*
*/
/*
* An overview of the pipelined operation mode.
*
* In the pipelined write mode, we will usually just add requests to our
* pipeline and return immediately, before we even start to service them. The
* user program will then have enough time to prepare the next request while
* we are still busy servicing previous requests. In the pipelined read mode,
* the situation is similar - we add read-ahead requests into the pipeline,
* before the user even requested them.
*
* The pipeline can be viewed as a "safety net" which will be activated when
* the system load is high and prevents the user backup program from keeping up
* with the current tape speed. At this point, the pipeline will get
* shorter and shorter but the tape will still be streaming at the same speed.
* Assuming we have enough pipeline stages, the system load will hopefully
* decrease before the pipeline is completely empty, and the backup program
* will be able to "catch up" and refill the pipeline again.
*
* When using the pipelined mode, it would be best to disable any type of
* buffering done by the user program, as ide-tape already provides all the
* benefits in the kernel, where it can be done in a more efficient way.
* As we will usually not block the user program on a request, the most
* efficient user code will then be a simple read-write-read-... cycle.
* Any additional logic will usually just slow down the backup process.
*
* Using the pipelined mode, I get a constant over 400 KBps throughput,
* which seems to be the maximum throughput supported by my tape.
*
* However, there are some downfalls:
*
* 1. We use memory (for data buffers) in proportional to the number
* of pipeline stages (each stage is about 26 KB with my tape).
* 2. In the pipelined write mode, we cheat and postpone error codes
* to the user task. In read mode, the actual tape position
* will be a bit further than the last requested block.
*
* Concerning (1):
*
* 1. We allocate stages dynamically only when we need them. When
* we don't need them, we don't consume additional memory. In
* case we can't allocate stages, we just manage without them
* (at the expense of decreased throughput) so when Linux is
* tight in memory, we will not pose additional difficulties.
*
* 2. The maximum number of stages (which is, in fact, the maximum
* amount of memory) which we allocate is limited by the compile
* time parameter IDETAPE_MAX_PIPELINE_STAGES.
*
* 3. The maximum number of stages is a controlled parameter - We
* don't start from the user defined maximum number of stages
* but from the lower IDETAPE_MIN_PIPELINE_STAGES (again, we
* will not even allocate this amount of stages if the user
* program can't handle the speed). We then implement a feedback
* loop which checks if the pipeline is empty, and if it is, we
* increase the maximum number of stages as necessary until we
* reach the optimum value which just manages to keep the tape
* busy with minimum allocated memory or until we reach
* IDETAPE_MAX_PIPELINE_STAGES.
*
* Concerning (2):
*
* In pipelined write mode, ide-tape can not return accurate error codes
* to the user program since we usually just add the request to the
* pipeline without waiting for it to be serviced. In case an error
* occurs, I will report it on the next user request.
*
* In the pipelined read mode, subsequent read requests or forward
* filemark spacing will perform correctly, as we preserve all blocks
* and filemarks which we encountered during our excess read-ahead.
*
* For accurate tape positioning and error reporting, disabling
* pipelined mode might be the best option.
*
* You can enable/disable/tune the pipelined operation mode by adjusting
* the compile time parameters below.
*/
/*
* Possible improvements.
*
* 1. Support for the ATAPI overlap protocol.
*
* In order to maximize bus throughput, we currently use the DSC
* overlap method which enables ide.c to service requests from the
* other device while the tape is busy executing a command. The
* DSC overlap method involves polling the tape's status register
* for the DSC bit, and servicing the other device while the tape
* isn't ready.
*
* In the current QIC development standard (December 1995),
* it is recommended that new tape drives will *in addition*
* implement the ATAPI overlap protocol, which is used for the
* same purpose - efficient use of the IDE bus, but is interrupt
* driven and thus has much less CPU overhead.
*
* ATAPI overlap is likely to be supported in most new ATAPI
* devices, including new ATAPI cdroms, and thus provides us
* a method by which we can achieve higher throughput when
* sharing a (fast) ATA-2 disk with any (slow) new ATAPI device.
*/
#define IDETAPE_VERSION "1.19"
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/jiffies.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/ide.h>
#include <linux/smp_lock.h>
#include <linux/completion.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/unaligned.h>
/*
* partition
*/
typedef struct os_partition_s {
__u8 partition_num;
__u8 par_desc_ver;
__u16 wrt_pass_cntr;
__u32 first_frame_addr;
__u32 last_frame_addr;
__u32 eod_frame_addr;
} os_partition_t;
/*
* DAT entry
*/
typedef struct os_dat_entry_s {
__u32 blk_sz;
__u16 blk_cnt;
__u8 flags;
__u8 reserved;
} os_dat_entry_t;
/*
* DAT
*/
#define OS_DAT_FLAGS_DATA (0xc)
#define OS_DAT_FLAGS_MARK (0x1)
typedef struct os_dat_s {
__u8 dat_sz;
__u8 reserved1;
__u8 entry_cnt;
__u8 reserved3;
os_dat_entry_t dat_list[16];
} os_dat_t;
#include <linux/mtio.h>
/**************************** Tunable parameters *****************************/
/*
* Pipelined mode parameters.
*
* We try to use the minimum number of stages which is enough to
* keep the tape constantly streaming. To accomplish that, we implement
* a feedback loop around the maximum number of stages:
*
* We start from MIN maximum stages (we will not even use MIN stages
* if we don't need them), increment it by RATE*(MAX-MIN)
* whenever we sense that the pipeline is empty, until we reach
* the optimum value or until we reach MAX.
*
* Setting the following parameter to 0 is illegal: the pipelined mode
* cannot be disabled (calculate_speeds() divides by tape->max_stages.)
*/
#define IDETAPE_MIN_PIPELINE_STAGES 1
#define IDETAPE_MAX_PIPELINE_STAGES 400
#define IDETAPE_INCREASE_STAGES_RATE 20
/*
* The following are used to debug the driver:
*
* Setting IDETAPE_DEBUG_INFO to 1 will report device capabilities.
* Setting IDETAPE_DEBUG_LOG to 1 will log driver flow control.
* Setting IDETAPE_DEBUG_BUGS to 1 will enable self-sanity checks in
* some places.
*
* Setting them to 0 will restore normal operation mode:
*
* 1. Disable logging normal successful operations.
* 2. Disable self-sanity checks.
* 3. Errors will still be logged, of course.
*
* All the #if DEBUG code will be removed some day, when the driver
* is verified to be stable enough. This will make it much more
* esthetic.
*/
#define IDETAPE_DEBUG_INFO 0
#define IDETAPE_DEBUG_LOG 0
#define IDETAPE_DEBUG_BUGS 1
/*
* After each failed packet command we issue a request sense command
* and retry the packet command IDETAPE_MAX_PC_RETRIES times.
*
* Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
*/
#define IDETAPE_MAX_PC_RETRIES 3
/*
* With each packet command, we allocate a buffer of
* IDETAPE_PC_BUFFER_SIZE bytes. This is used for several packet
* commands (Not for READ/WRITE commands).
*/
#define IDETAPE_PC_BUFFER_SIZE 256
/*
* In various places in the driver, we need to allocate storage
* for packet commands and requests, which will remain valid while
* we leave the driver to wait for an interrupt or a timeout event.
*/
#define IDETAPE_PC_STACK (10 + IDETAPE_MAX_PC_RETRIES)
/*
* Some drives (for example, Seagate STT3401A Travan) require a very long
* timeout, because they don't return an interrupt or clear their busy bit
* until after the command completes (even retension commands).
*/
#define IDETAPE_WAIT_CMD (900*HZ)
/*
* The following parameter is used to select the point in the internal
* tape fifo in which we will start to refill the buffer. Decreasing
* the following parameter will improve the system's latency and
* interactive response, while using a high value might improve sytem
* throughput.
*/
#define IDETAPE_FIFO_THRESHOLD 2
/*
* DSC polling parameters.
*
* Polling for DSC (a single bit in the status register) is a very
* important function in ide-tape. There are two cases in which we
* poll for DSC:
*
* 1. Before a read/write packet command, to ensure that we
* can transfer data from/to the tape's data buffers, without
* causing an actual media access. In case the tape is not
* ready yet, we take out our request from the device
* request queue, so that ide.c will service requests from
* the other device on the same interface meanwhile.
*
* 2. After the successful initialization of a "media access
* packet command", which is a command which can take a long
* time to complete (it can be several seconds or even an hour).
*
* Again, we postpone our request in the middle to free the bus
* for the other device. The polling frequency here should be
* lower than the read/write frequency since those media access
* commands are slow. We start from a "fast" frequency -
* IDETAPE_DSC_MA_FAST (one second), and if we don't receive DSC
* after IDETAPE_DSC_MA_THRESHOLD (5 minutes), we switch it to a
* lower frequency - IDETAPE_DSC_MA_SLOW (1 minute).
*
* We also set a timeout for the timer, in case something goes wrong.
* The timeout should be longer then the maximum execution time of a
* tape operation.
*/
/*
* DSC timings.
*/
#define IDETAPE_DSC_RW_MIN 5*HZ/100 /* 50 msec */
#define IDETAPE_DSC_RW_MAX 40*HZ/100 /* 400 msec */
#define IDETAPE_DSC_RW_TIMEOUT 2*60*HZ /* 2 minutes */
#define IDETAPE_DSC_MA_FAST 2*HZ /* 2 seconds */
#define IDETAPE_DSC_MA_THRESHOLD 5*60*HZ /* 5 minutes */
#define IDETAPE_DSC_MA_SLOW 30*HZ /* 30 seconds */
#define IDETAPE_DSC_MA_TIMEOUT 2*60*60*HZ /* 2 hours */
/*************************** End of tunable parameters ***********************/
/*
* Debugging/Performance analysis
*
* I/O trace support
*/
#define USE_IOTRACE 0
#if USE_IOTRACE
#include <linux/io_trace.h>
#define IO_IDETAPE_FIFO 500
#endif
/*
* Read/Write error simulation
*/
#define SIMULATE_ERRORS 0
/*
* For general magnetic tape device compatibility.
*/
typedef enum {
idetape_direction_none,
idetape_direction_read,
idetape_direction_write
} idetape_chrdev_direction_t;
struct idetape_bh {
unsigned short b_size;
atomic_t b_count;
struct idetape_bh *b_reqnext;
char *b_data;
};
/*
* Our view of a packet command.
*/
typedef struct idetape_packet_command_s {
u8 c[12]; /* Actual packet bytes */
int retries; /* On each retry, we increment retries */
int error; /* Error code */
int request_transfer; /* Bytes to transfer */
int actually_transferred; /* Bytes actually transferred */
int buffer_size; /* Size of our data buffer */
struct idetape_bh *bh;
char *b_data;
int b_count;
u8 *buffer; /* Data buffer */
u8 *current_position; /* Pointer into the above buffer */
ide_startstop_t (*callback) (ide_drive_t *); /* Called when this packet command is completed */
u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE]; /* Temporary buffer */
unsigned long flags; /* Status/Action bit flags: long for set_bit */
} idetape_pc_t;
/*
* Packet command flag bits.
*/
/* Set when an error is considered normal - We won't retry */
#define PC_ABORT 0
/* 1 When polling for DSC on a media access command */
#define PC_WAIT_FOR_DSC 1
/* 1 when we prefer to use DMA if possible */
#define PC_DMA_RECOMMENDED 2
/* 1 while DMA in progress */
#define PC_DMA_IN_PROGRESS 3
/* 1 when encountered problem during DMA */
#define PC_DMA_ERROR 4
/* Data direction */
#define PC_WRITING 5
/*
* Capabilities and Mechanical Status Page
*/
typedef struct {
unsigned page_code :6; /* Page code - Should be 0x2a */
__u8 reserved0_6 :1;
__u8 ps :1; /* parameters saveable */
__u8 page_length; /* Page Length - Should be 0x12 */
__u8 reserved2, reserved3;
unsigned ro :1; /* Read Only Mode */
unsigned reserved4_1234 :4;
unsigned sprev :1; /* Supports SPACE in the reverse direction */
unsigned reserved4_67 :2;
unsigned reserved5_012 :3;
unsigned efmt :1; /* Supports ERASE command initiated formatting */
unsigned reserved5_4 :1;
unsigned qfa :1; /* Supports the QFA two partition formats */
unsigned reserved5_67 :2;
unsigned lock :1; /* Supports locking the volume */
unsigned locked :1; /* The volume is locked */
unsigned prevent :1; /* The device defaults in the prevent state after power up */
unsigned eject :1; /* The device can eject the volume */
__u8 disconnect :1; /* The device can break request > ctl */
__u8 reserved6_5 :1;
unsigned ecc :1; /* Supports error correction */
unsigned cmprs :1; /* Supports data compression */
unsigned reserved7_0 :1;
unsigned blk512 :1; /* Supports 512 bytes block size */
unsigned blk1024 :1; /* Supports 1024 bytes block size */
unsigned reserved7_3_6 :4;
unsigned blk32768 :1; /* slowb - the device restricts the byte count for PIO */
/* transfers for slow buffer memory ??? */
/* Also 32768 block size in some cases */
__u16 max_speed; /* Maximum speed supported in KBps */
__u8 reserved10, reserved11;
__u16 ctl; /* Continuous Transfer Limit in blocks */
__u16 speed; /* Current Speed, in KBps */
__u16 buffer_size; /* Buffer Size, in 512 bytes */
__u8 reserved18, reserved19;
} idetape_capabilities_page_t;
/*
* Block Size Page
*/
typedef struct {
unsigned page_code :6; /* Page code - Should be 0x30 */
unsigned reserved1_6 :1;
unsigned ps :1;
__u8 page_length; /* Page Length - Should be 2 */
__u8 reserved2;
unsigned play32 :1;
unsigned play32_5 :1;
unsigned reserved2_23 :2;
unsigned record32 :1;
unsigned record32_5 :1;
unsigned reserved2_6 :1;
unsigned one :1;
} idetape_block_size_page_t;
/*
* A pipeline stage.
*/
typedef struct idetape_stage_s {
struct request rq; /* The corresponding request */
struct idetape_bh *bh; /* The data buffers */
struct idetape_stage_s *next; /* Pointer to the next stage */
} idetape_stage_t;
/*
* REQUEST SENSE packet command result - Data Format.
*/
typedef struct {
unsigned error_code :7; /* Current of deferred errors */
unsigned valid :1; /* The information field conforms to QIC-157C */
__u8 reserved1 :8; /* Segment Number - Reserved */
unsigned sense_key :4; /* Sense Key */
unsigned reserved2_4 :1; /* Reserved */
unsigned ili :1; /* Incorrect Length Indicator */
unsigned eom :1; /* End Of Medium */
unsigned filemark :1; /* Filemark */
__u32 information __attribute__ ((packed));
__u8 asl; /* Additional sense length (n-7) */
__u32 command_specific; /* Additional command specific information */
__u8 asc; /* Additional Sense Code */
__u8 ascq; /* Additional Sense Code Qualifier */
__u8 replaceable_unit_code; /* Field Replaceable Unit Code */
unsigned sk_specific1 :7; /* Sense Key Specific */
unsigned sksv :1; /* Sense Key Specific information is valid */
__u8 sk_specific2; /* Sense Key Specific */
__u8 sk_specific3; /* Sense Key Specific */
__u8 pad[2]; /* Padding to 20 bytes */
} idetape_request_sense_result_t;
/*
* Most of our global data which we need to save even as we leave the
* driver due to an interrupt or a timer event is stored in a variable
* of type idetape_tape_t, defined below.
*/
typedef struct ide_tape_obj {
ide_drive_t *drive;
ide_driver_t *driver;
struct gendisk *disk;
struct kref kref;
/*
* Since a typical character device operation requires more
* than one packet command, we provide here enough memory
* for the maximum of interconnected packet commands.
* The packet commands are stored in the circular array pc_stack.
* pc_stack_index points to the last used entry, and warps around
* to the start when we get to the last array entry.
*
* pc points to the current processed packet command.
*
* failed_pc points to the last failed packet command, or contains
* NULL if we do not need to retry any packet command. This is
* required since an additional packet command is needed before the
* retry, to get detailed information on what went wrong.
*/
/* Current packet command */
idetape_pc_t *pc;
/* Last failed packet command */
idetape_pc_t *failed_pc;
/* Packet command stack */
idetape_pc_t pc_stack[IDETAPE_PC_STACK];
/* Next free packet command storage space */
int pc_stack_index;
struct request rq_stack[IDETAPE_PC_STACK];
/* We implement a circular array */
int rq_stack_index;
/*
* DSC polling variables.
*
* While polling for DSC we use postponed_rq to postpone the
* current request so that ide.c will be able to service
* pending requests on the other device. Note that at most
* we will have only one DSC (usually data transfer) request
* in the device request queue. Additional requests can be
* queued in our internal pipeline, but they will be visible
* to ide.c only one at a time.
*/
struct request *postponed_rq;
/* The time in which we started polling for DSC */
unsigned long dsc_polling_start;
/* Timer used to poll for dsc */
struct timer_list dsc_timer;
/* Read/Write dsc polling frequency */
unsigned long best_dsc_rw_frequency;
/* The current polling frequency */
unsigned long dsc_polling_frequency;
/* Maximum waiting time */
unsigned long dsc_timeout;
/*
* Read position information
*/
u8 partition;
/* Current block */
unsigned int first_frame_position;
unsigned int last_frame_position;
unsigned int blocks_in_buffer;
/*
* Last error information
*/
u8 sense_key, asc, ascq;
/*
* Character device operation
*/
unsigned int minor;
/* device name */
char name[4];
/* Current character device data transfer direction */
idetape_chrdev_direction_t chrdev_direction;
/*
* Device information
*/
/* Usually 512 or 1024 bytes */
unsigned short tape_block_size;
int user_bs_factor;
/* Copy of the tape's Capabilities and Mechanical Page */
idetape_capabilities_page_t capabilities;
/*
* Active data transfer request parameters.
*
* At most, there is only one ide-tape originated data transfer
* request in the device request queue. This allows ide.c to
* easily service requests from the other device when we
* postpone our active request. In the pipelined operation
* mode, we use our internal pipeline structure to hold
* more data requests.
*
* The data buffer size is chosen based on the tape's
* recommendation.
*/
/* Pointer to the request which is waiting in the device request queue */
struct request *active_data_request;
/* Data buffer size (chosen based on the tape's recommendation */
int stage_size;
idetape_stage_t *merge_stage;
int merge_stage_size;
struct idetape_bh *bh;
char *b_data;
int b_count;
/*
* Pipeline parameters.
*
* To accomplish non-pipelined mode, we simply set the following
* variables to zero (or NULL, where appropriate).
*/
/* Number of currently used stages */
int nr_stages;
/* Number of pending stages */
int nr_pending_stages;
/* We will not allocate more than this number of stages */
int max_stages, min_pipeline, max_pipeline;
/* The first stage which will be removed from the pipeline */
idetape_stage_t *first_stage;
/* The currently active stage */
idetape_stage_t *active_stage;
/* Will be serviced after the currently active request */
idetape_stage_t *next_stage;
/* New requests will be added to the pipeline here */
idetape_stage_t *last_stage;
/* Optional free stage which we can use */
idetape_stage_t *cache_stage;
int pages_per_stage;
/* Wasted space in each stage */
int excess_bh_size;
/* Status/Action flags: long for set_bit */
unsigned long flags;
/* protects the ide-tape queue */
spinlock_t spinlock;
/*
* Measures average tape speed
*/
unsigned long avg_time;
int avg_size;
int avg_speed;
/* last sense information */
idetape_request_sense_result_t sense;
char vendor_id[10];
char product_id[18];
char firmware_revision[6];
int firmware_revision_num;
/* the door is currently locked */
int door_locked;
/* the tape hardware is write protected */
char drv_write_prot;
/* the tape is write protected (hardware or opened as read-only) */
char write_prot;
/*
* Limit the number of times a request can
* be postponed, to avoid an infinite postpone
* deadlock.
*/
/* request postpone count limit */
int postpone_cnt;
/*
* Measures number of frames:
*
* 1. written/read to/from the driver pipeline (pipeline_head).
* 2. written/read to/from the tape buffers (idetape_bh).
* 3. written/read by the tape to/from the media (tape_head).
*/
int pipeline_head;
int buffer_head;
int tape_head;
int last_tape_head;
/*
* Speed control at the tape buffers input/output
*/
unsigned long insert_time;
int insert_size;
int insert_speed;
int max_insert_speed;
int measure_insert_time;
/*
* Measure tape still time, in milliseconds
*/
unsigned long tape_still_time_begin;
int tape_still_time;
/*
* Speed regulation negative feedback loop
*/
int speed_control;
int pipeline_head_speed;
int controlled_pipeline_head_speed;
int uncontrolled_pipeline_head_speed;
int controlled_last_pipeline_head;
int uncontrolled_last_pipeline_head;
unsigned long uncontrolled_pipeline_head_time;
unsigned long controlled_pipeline_head_time;
int controlled_previous_pipeline_head;
int uncontrolled_previous_pipeline_head;
unsigned long controlled_previous_head_time;
unsigned long uncontrolled_previous_head_time;
int restart_speed_control_req;
/*
* Debug_level determines amount of debugging output;
* can be changed using /proc/ide/hdx/settings
* 0 : almost no debugging output
* 1 : 0+output errors only
* 2 : 1+output all sensekey/asc
* 3 : 2+follow all chrdev related procedures
* 4 : 3+follow all procedures
* 5 : 4+include pc_stack rq_stack info
* 6 : 5+USE_COUNT updates
*/
int debug_level;
} idetape_tape_t;
static DEFINE_MUTEX(idetape_ref_mutex);
static struct class *idetape_sysfs_class;
#define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref)
#define ide_tape_g(disk) \
container_of((disk)->private_data, struct ide_tape_obj, driver)
static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
{
struct ide_tape_obj *tape = NULL;
mutex_lock(&idetape_ref_mutex);
tape = ide_tape_g(disk);
if (tape)
kref_get(&tape->kref);
mutex_unlock(&idetape_ref_mutex);
return tape;
}
static void ide_tape_release(struct kref *);
static void ide_tape_put(struct ide_tape_obj *tape)
{
mutex_lock(&idetape_ref_mutex);
kref_put(&tape->kref, ide_tape_release);
mutex_unlock(&idetape_ref_mutex);
}
/*
* Tape door status
*/
#define DOOR_UNLOCKED 0
#define DOOR_LOCKED 1
#define DOOR_EXPLICITLY_LOCKED 2
/*
* Tape flag bits values.
*/
#define IDETAPE_IGNORE_DSC 0
#define IDETAPE_ADDRESS_VALID 1 /* 0 When the tape position is unknown */
#define IDETAPE_BUSY 2 /* Device already opened */
#define IDETAPE_PIPELINE_ERROR 3 /* Error detected in a pipeline stage */
#define IDETAPE_DETECT_BS 4 /* Attempt to auto-detect the current user block size */
#define IDETAPE_FILEMARK 5 /* Currently on a filemark */
#define IDETAPE_DRQ_INTERRUPT 6 /* DRQ interrupt device */
#define IDETAPE_READ_ERROR 7
#define IDETAPE_PIPELINE_ACTIVE 8 /* pipeline active */
/* 0 = no tape is loaded, so we don't rewind after ejecting */
#define IDETAPE_MEDIUM_PRESENT 9
/*
* Supported ATAPI tape drives packet commands
*/
#define IDETAPE_TEST_UNIT_READY_CMD 0x00
#define IDETAPE_REWIND_CMD 0x01
#define IDETAPE_REQUEST_SENSE_CMD 0x03
#define IDETAPE_READ_CMD 0x08
#define IDETAPE_WRITE_CMD 0x0a
#define IDETAPE_WRITE_FILEMARK_CMD 0x10
#define IDETAPE_SPACE_CMD 0x11
#define IDETAPE_INQUIRY_CMD 0x12
#define IDETAPE_ERASE_CMD 0x19
#define IDETAPE_MODE_SENSE_CMD 0x1a
#define IDETAPE_MODE_SELECT_CMD 0x15
#define IDETAPE_LOAD_UNLOAD_CMD 0x1b
#define IDETAPE_PREVENT_CMD 0x1e
#define IDETAPE_LOCATE_CMD 0x2b
#define IDETAPE_READ_POSITION_CMD 0x34
#define IDETAPE_READ_BUFFER_CMD 0x3c
#define IDETAPE_SET_SPEED_CMD 0xbb
/*
* Some defines for the READ BUFFER command
*/
#define IDETAPE_RETRIEVE_FAULTY_BLOCK 6
/*
* Some defines for the SPACE command
*/
#define IDETAPE_SPACE_OVER_FILEMARK 1
#define IDETAPE_SPACE_TO_EOD 3
/*
* Some defines for the LOAD UNLOAD command
*/
#define IDETAPE_LU_LOAD_MASK 1
#define IDETAPE_LU_RETENSION_MASK 2
#define IDETAPE_LU_EOT_MASK 4
/*
* Special requests for our block device strategy routine.
*
* In order to service a character device command, we add special
* requests to the tail of our block device request queue and wait
* for their completion.
*/
enum {
REQ_IDETAPE_PC1 = (1 << 0), /* packet command (first stage) */
REQ_IDETAPE_PC2 = (1 << 1), /* packet command (second stage) */
REQ_IDETAPE_READ = (1 << 2),
REQ_IDETAPE_WRITE = (1 << 3),
REQ_IDETAPE_READ_BUFFER = (1 << 4),
};
/*
* Error codes which are returned in rq->errors to the higher part
* of the driver.
*/
#define IDETAPE_ERROR_GENERAL 101
#define IDETAPE_ERROR_FILEMARK 102
#define IDETAPE_ERROR_EOD 103
/*
* The following is used to format the general configuration word of
* the ATAPI IDENTIFY DEVICE command.
*/
struct idetape_id_gcw {
unsigned packet_size :2; /* Packet Size */
unsigned reserved234 :3; /* Reserved */
unsigned drq_type :2; /* Command packet DRQ type */
unsigned removable :1; /* Removable media */
unsigned device_type :5; /* Device type */
unsigned reserved13 :1; /* Reserved */
unsigned protocol :2; /* Protocol type */
};
/*
* INQUIRY packet command - Data Format (From Table 6-8 of QIC-157C)
*/
typedef struct {
unsigned device_type :5; /* Peripheral Device Type */
unsigned reserved0_765 :3; /* Peripheral Qualifier - Reserved */
unsigned reserved1_6t0 :7; /* Reserved */
unsigned rmb :1; /* Removable Medium Bit */
unsigned ansi_version :3; /* ANSI Version */
unsigned ecma_version :3; /* ECMA Version */
unsigned iso_version :2; /* ISO Version */
unsigned response_format :4; /* Response Data Format */
unsigned reserved3_45 :2; /* Reserved */
unsigned reserved3_6 :1; /* TrmIOP - Reserved */
unsigned reserved3_7 :1; /* AENC - Reserved */
__u8 additional_length; /* Additional Length (total_length-4) */
__u8 rsv5, rsv6, rsv7; /* Reserved */
__u8 vendor_id[8]; /* Vendor Identification */
__u8 product_id[16]; /* Product Identification */
__u8 revision_level[4]; /* Revision Level */
__u8 vendor_specific[20]; /* Vendor Specific - Optional */
__u8 reserved56t95[40]; /* Reserved - Optional */
/* Additional information may be returned */
} idetape_inquiry_result_t;
/*
* READ POSITION packet command - Data Format (From Table 6-57)
*/
typedef struct {
unsigned reserved0_10 :2; /* Reserved */
unsigned bpu :1; /* Block Position Unknown */
unsigned reserved0_543 :3; /* Reserved */
unsigned eop :1; /* End Of Partition */
unsigned bop :1; /* Beginning Of Partition */
u8 partition; /* Partition Number */
u8 reserved2, reserved3; /* Reserved */
u32 first_block; /* First Block Location */
u32 last_block; /* Last Block Location (Optional) */
u8 reserved12; /* Reserved */
u8 blocks_in_buffer[3]; /* Blocks In Buffer - (Optional) */
u32 bytes_in_buffer; /* Bytes In Buffer (Optional) */
} idetape_read_position_result_t;
/*
* Follows structures which are related to the SELECT SENSE / MODE SENSE
* packet commands. Those packet commands are still not supported
* by ide-tape.
*/
#define IDETAPE_BLOCK_DESCRIPTOR 0
#define IDETAPE_CAPABILITIES_PAGE 0x2a
#define IDETAPE_PARAMTR_PAGE 0x2b /* Onstream DI-x0 only */
#define IDETAPE_BLOCK_SIZE_PAGE 0x30
#define IDETAPE_BUFFER_FILLING_PAGE 0x33
/*
* Mode Parameter Header for the MODE SENSE packet command
*/
typedef struct {
__u8 mode_data_length; /* Length of the following data transfer */
__u8 medium_type; /* Medium Type */
__u8 dsp; /* Device Specific Parameter */
__u8 bdl; /* Block Descriptor Length */
#if 0
/* data transfer page */
__u8 page_code :6;
__u8 reserved0_6 :1;
__u8 ps :1; /* parameters saveable */
__u8 page_length; /* page Length == 0x02 */
__u8 reserved2;
__u8 read32k :1; /* 32k blk size (data only) */
__u8 read32k5 :1; /* 32.5k blk size (data&AUX) */
__u8 reserved3_23 :2;
__u8 write32k :1; /* 32k blk size (data only) */
__u8 write32k5 :1; /* 32.5k blk size (data&AUX) */
__u8 reserved3_6 :1;
__u8 streaming :1; /* streaming mode enable */
#endif
} idetape_mode_parameter_header_t;
/*
* Mode Parameter Block Descriptor the MODE SENSE packet command
*
* Support for block descriptors is optional.
*/
typedef struct {
__u8 density_code; /* Medium density code */
__u8 blocks[3]; /* Number of blocks */
__u8 reserved4; /* Reserved */
__u8 length[3]; /* Block Length */
} idetape_parameter_block_descriptor_t;
/*
* The Data Compression Page, as returned by the MODE SENSE packet command.
*/
typedef struct {
unsigned page_code :6; /* Page Code - Should be 0xf */
unsigned reserved0 :1; /* Reserved */
unsigned ps :1;
__u8 page_length; /* Page Length - Should be 14 */
unsigned reserved2 :6; /* Reserved */
unsigned dcc :1; /* Data Compression Capable */
unsigned dce :1; /* Data Compression Enable */
unsigned reserved3 :5; /* Reserved */
unsigned red :2; /* Report Exception on Decompression */
unsigned dde :1; /* Data Decompression Enable */
__u32 ca; /* Compression Algorithm */
__u32 da; /* Decompression Algorithm */
__u8 reserved[4]; /* Reserved */
} idetape_data_compression_page_t;
/*
* The Medium Partition Page, as returned by the MODE SENSE packet command.
*/
typedef struct {
unsigned page_code :6; /* Page Code - Should be 0x11 */
unsigned reserved1_6 :1; /* Reserved */
unsigned ps :1;
__u8 page_length; /* Page Length - Should be 6 */
__u8 map; /* Maximum Additional Partitions - Should be 0 */
__u8 apd; /* Additional Partitions Defined - Should be 0 */
unsigned reserved4_012 :3; /* Reserved */
unsigned psum :2; /* Should be 0 */
unsigned idp :1; /* Should be 0 */
unsigned sdp :1; /* Should be 0 */
unsigned fdp :1; /* Fixed Data Partitions */
__u8 mfr; /* Medium Format Recognition */
__u8 reserved[2]; /* Reserved */
} idetape_medium_partition_page_t;
/*
* Run time configurable parameters.
*/
typedef struct {
int dsc_rw_frequency;
int dsc_media_access_frequency;
int nr_stages;
} idetape_config_t;
/*
* The variables below are used for the character device interface.
* Additional state variables are defined in our ide_drive_t structure.
*/
static struct ide_tape_obj * idetape_devs[MAX_HWIFS * MAX_DRIVES];
#define ide_tape_f(file) ((file)->private_data)
static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
{
struct ide_tape_obj *tape = NULL;
mutex_lock(&idetape_ref_mutex);
tape = idetape_devs[i];
if (tape)
kref_get(&tape->kref);
mutex_unlock(&idetape_ref_mutex);
return tape;
}
/*
* Function declarations
*
*/
static int idetape_chrdev_release (struct inode *inode, struct file *filp);
static void idetape_write_release (ide_drive_t *drive, unsigned int minor);
/*
* Too bad. The drive wants to send us data which we are not ready to accept.
* Just throw it away.
*/
static void idetape_discard_data (ide_drive_t *drive, unsigned int bcount)
{
while (bcount--)
(void) HWIF(drive)->INB(IDE_DATA_REG);
}
static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
{
struct idetape_bh *bh = pc->bh;
int count;
while (bcount) {
#if IDETAPE_DEBUG_BUGS
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_input_buffers\n");
idetape_discard_data(drive, bcount);
return;
}
#endif /* IDETAPE_DEBUG_BUGS */
count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), bcount);
HWIF(drive)->atapi_input_bytes(drive, bh->b_data + atomic_read(&bh->b_count), count);
bcount -= count;
atomic_add(count, &bh->b_count);
if (atomic_read(&bh->b_count) == bh->b_size) {
bh = bh->b_reqnext;
if (bh)
atomic_set(&bh->b_count, 0);
}
}
pc->bh = bh;
}
static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
{
struct idetape_bh *bh = pc->bh;
int count;
while (bcount) {
#if IDETAPE_DEBUG_BUGS
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_output_buffers\n");
return;
}
#endif /* IDETAPE_DEBUG_BUGS */
count = min((unsigned int)pc->b_count, (unsigned int)bcount);
HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count);
bcount -= count;
pc->b_data += count;
pc->b_count -= count;
if (!pc->b_count) {
pc->bh = bh = bh->b_reqnext;
if (bh) {
pc->b_data = bh->b_data;
pc->b_count = atomic_read(&bh->b_count);
}
}
}
}
static void idetape_update_buffers (idetape_pc_t *pc)
{
struct idetape_bh *bh = pc->bh;
int count;
unsigned int bcount = pc->actually_transferred;
if (test_bit(PC_WRITING, &pc->flags))
return;
while (bcount) {
#if IDETAPE_DEBUG_BUGS
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_update_buffers\n");
return;
}
#endif /* IDETAPE_DEBUG_BUGS */
count = min((unsigned int)bh->b_size, (unsigned int)bcount);
atomic_set(&bh->b_count, count);
if (atomic_read(&bh->b_count) == bh->b_size)
bh = bh->b_reqnext;
bcount -= count;
}
pc->bh = bh;
}
/*
* idetape_next_pc_storage returns a pointer to a place in which we can
* safely store a packet command, even though we intend to leave the
* driver. A storage space for a maximum of IDETAPE_PC_STACK packet
* commands is allocated at initialization time.
*/
static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 5)
printk(KERN_INFO "ide-tape: pc_stack_index=%d\n",
tape->pc_stack_index);
#endif /* IDETAPE_DEBUG_LOG */
if (tape->pc_stack_index == IDETAPE_PC_STACK)
tape->pc_stack_index=0;
return (&tape->pc_stack[tape->pc_stack_index++]);
}
/*
* idetape_next_rq_storage is used along with idetape_next_pc_storage.
* Since we queue packet commands in the request queue, we need to
* allocate a request, along with the allocation of a packet command.
*/
/**************************************************************
* *
* This should get fixed to use kmalloc(.., GFP_ATOMIC) *
* followed later on by kfree(). -ml *
* *
**************************************************************/
static struct request *idetape_next_rq_storage (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 5)
printk(KERN_INFO "ide-tape: rq_stack_index=%d\n",
tape->rq_stack_index);
#endif /* IDETAPE_DEBUG_LOG */
if (tape->rq_stack_index == IDETAPE_PC_STACK)
tape->rq_stack_index=0;
return (&tape->rq_stack[tape->rq_stack_index++]);
}
/*
* idetape_init_pc initializes a packet command.
*/
static void idetape_init_pc (idetape_pc_t *pc)
{
memset(pc->c, 0, 12);
pc->retries = 0;
pc->flags = 0;
pc->request_transfer = 0;
pc->buffer = pc->pc_buffer;
pc->buffer_size = IDETAPE_PC_BUFFER_SIZE;
pc->bh = NULL;
pc->b_data = NULL;
}
/*
* idetape_analyze_error is called on each failed packet command retry
* to analyze the request sense. We currently do not utilize this
* information.
*/
static void idetape_analyze_error (ide_drive_t *drive, idetape_request_sense_result_t *result)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc = tape->failed_pc;
tape->sense = *result;
tape->sense_key = result->sense_key;
tape->asc = result->asc;
tape->ascq = result->ascq;
#if IDETAPE_DEBUG_LOG
/*
* Without debugging, we only log an error if we decided to
* give up retrying.
*/
if (tape->debug_level >= 1)
printk(KERN_INFO "ide-tape: pc = %x, sense key = %x, "
"asc = %x, ascq = %x\n",
pc->c[0], result->sense_key,
result->asc, result->ascq);
#endif /* IDETAPE_DEBUG_LOG */
/*
* Correct pc->actually_transferred by asking the tape.
*/
if (test_bit(PC_DMA_ERROR, &pc->flags)) {
pc->actually_transferred = pc->request_transfer - tape->tape_block_size * ntohl(get_unaligned(&result->information));
idetape_update_buffers(pc);
}
/*
* If error was the result of a zero-length read or write command,
* with sense key=5, asc=0x22, ascq=0, let it slide. Some drives
* (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
*/
if ((pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD)
&& pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) { /* length==0 */
if (result->sense_key == 5) {
/* don't report an error, everything's ok */
pc->error = 0;
/* don't retry read/write */
set_bit(PC_ABORT, &pc->flags);
}
}
if (pc->c[0] == IDETAPE_READ_CMD && result->filemark) {
pc->error = IDETAPE_ERROR_FILEMARK;
set_bit(PC_ABORT, &pc->flags);
}
if (pc->c[0] == IDETAPE_WRITE_CMD) {
if (result->eom ||
(result->sense_key == 0xd && result->asc == 0x0 &&
result->ascq == 0x2)) {
pc->error = IDETAPE_ERROR_EOD;
set_bit(PC_ABORT, &pc->flags);
}
}
if (pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD) {
if (result->sense_key == 8) {
pc->error = IDETAPE_ERROR_EOD;
set_bit(PC_ABORT, &pc->flags);
}
if (!test_bit(PC_ABORT, &pc->flags) &&
pc->actually_transferred)
pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
}
}
/*
* idetape_active_next_stage will declare the next stage as "active".
*/
static void idetape_active_next_stage (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_stage_t *stage = tape->next_stage;
struct request *rq = &stage->rq;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: Reached idetape_active_next_stage\n");
#endif /* IDETAPE_DEBUG_LOG */
#if IDETAPE_DEBUG_BUGS
if (stage == NULL) {
printk(KERN_ERR "ide-tape: bug: Trying to activate a non existing stage\n");
return;
}
#endif /* IDETAPE_DEBUG_BUGS */
rq->rq_disk = tape->disk;
rq->buffer = NULL;
rq->special = (void *)stage->bh;
tape->active_data_request = rq;
tape->active_stage = stage;
tape->next_stage = stage->next;
}
/*
* idetape_increase_max_pipeline_stages is a part of the feedback
* loop which tries to find the optimum number of stages. In the
* feedback loop, we are starting from a minimum maximum number of
* stages, and if we sense that the pipeline is empty, we try to
* increase it, until we reach the user compile time memory limit.
*/
static void idetape_increase_max_pipeline_stages (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
int increase = (tape->max_pipeline - tape->min_pipeline) / 10;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk (KERN_INFO "ide-tape: Reached idetape_increase_max_pipeline_stages\n");
#endif /* IDETAPE_DEBUG_LOG */
tape->max_stages += max(increase, 1);
tape->max_stages = max(tape->max_stages, tape->min_pipeline);
tape->max_stages = min(tape->max_stages, tape->max_pipeline);
}
/*
* idetape_kfree_stage calls kfree to completely free a stage, along with
* its related buffers.
*/
static void __idetape_kfree_stage (idetape_stage_t *stage)
{
struct idetape_bh *prev_bh, *bh = stage->bh;
int size;
while (bh != NULL) {
if (bh->b_data != NULL) {
size = (int) bh->b_size;
while (size > 0) {
free_page((unsigned long) bh->b_data);
size -= PAGE_SIZE;
bh->b_data += PAGE_SIZE;
}
}
prev_bh = bh;
bh = bh->b_reqnext;
kfree(prev_bh);
}
kfree(stage);
}
static void idetape_kfree_stage (idetape_tape_t *tape, idetape_stage_t *stage)
{
__idetape_kfree_stage(stage);
}
/*
* idetape_remove_stage_head removes tape->first_stage from the pipeline.
* The caller should avoid race conditions.
*/
static void idetape_remove_stage_head (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_stage_t *stage;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: Reached idetape_remove_stage_head\n");
#endif /* IDETAPE_DEBUG_LOG */
#if IDETAPE_DEBUG_BUGS
if (tape->first_stage == NULL) {
printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n");
return;
}
if (tape->active_stage == tape->first_stage) {
printk(KERN_ERR "ide-tape: bug: Trying to free our active pipeline stage\n");
return;
}
#endif /* IDETAPE_DEBUG_BUGS */
stage = tape->first_stage;
tape->first_stage = stage->next;
idetape_kfree_stage(tape, stage);
tape->nr_stages--;
if (tape->first_stage == NULL) {
tape->last_stage = NULL;
#if IDETAPE_DEBUG_BUGS
if (tape->next_stage != NULL)
printk(KERN_ERR "ide-tape: bug: tape->next_stage != NULL\n");
if (tape->nr_stages)
printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 now\n");
#endif /* IDETAPE_DEBUG_BUGS */
}
}
/*
* This will free all the pipeline stages starting from new_last_stage->next
* to the end of the list, and point tape->last_stage to new_last_stage.
*/
static void idetape_abort_pipeline(ide_drive_t *drive,
idetape_stage_t *new_last_stage)
{
idetape_tape_t *tape = drive->driver_data;
idetape_stage_t *stage = new_last_stage->next;
idetape_stage_t *nstage;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: %s: idetape_abort_pipeline called\n", tape->name);
#endif
while (stage) {
nstage = stage->next;
idetape_kfree_stage(tape, stage);
--tape->nr_stages;
--tape->nr_pending_stages;
stage = nstage;
}
if (new_last_stage)
new_last_stage->next = NULL;
tape->last_stage = new_last_stage;
tape->next_stage = NULL;
}
/*
* idetape_end_request is used to finish servicing a request, and to
* insert a pending pipeline request into the main device queue.
*/
static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
{
struct request *rq = HWGROUP(drive)->rq;
idetape_tape_t *tape = drive->driver_data;
unsigned long flags;
int error;
int remove_stage = 0;
idetape_stage_t *active_stage;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: Reached idetape_end_request\n");
#endif /* IDETAPE_DEBUG_LOG */
switch (uptodate) {
case 0: error = IDETAPE_ERROR_GENERAL; break;
case 1: error = 0; break;
default: error = uptodate;
}
rq->errors = error;
if (error)
tape->failed_pc = NULL;
spin_lock_irqsave(&tape->spinlock, flags);
/* The request was a pipelined data transfer request */
if (tape->active_data_request == rq) {
active_stage = tape->active_stage;
tape->active_stage = NULL;
tape->active_data_request = NULL;
tape->nr_pending_stages--;
if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
remove_stage = 1;
if (error) {
set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
if (error == IDETAPE_ERROR_EOD)
idetape_abort_pipeline(drive, active_stage);
}
} else if (rq->cmd[0] & REQ_IDETAPE_READ) {
if (error == IDETAPE_ERROR_EOD) {
set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
idetape_abort_pipeline(drive, active_stage);
}
}
if (tape->next_stage != NULL) {
idetape_active_next_stage(drive);
/*
* Insert the next request into the request queue.
*/
(void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
} else if (!error) {
idetape_increase_max_pipeline_stages(drive);
}
}
ide_end_drive_cmd(drive, 0, 0);
// blkdev_dequeue_request(rq);
// drive->rq = NULL;
// end_that_request_last(rq);
if (remove_stage)
idetape_remove_stage_head(drive);
if (tape->active_data_request == NULL)
clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
spin_unlock_irqrestore(&tape->spinlock, flags);
return 0;
}
static ide_startstop_t idetape_request_sense_callback (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: Reached idetape_request_sense_callback\n");
#endif /* IDETAPE_DEBUG_LOG */
if (!tape->pc->error) {
idetape_analyze_error(drive, (idetape_request_sense_result_t *) tape->pc->buffer);
idetape_end_request(drive, 1, 0);
} else {
printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - Aborting request!\n");
idetape_end_request(drive, 0, 0);
}
return ide_stopped;
}
static void idetape_create_request_sense_cmd (idetape_pc_t *pc)
{
idetape_init_pc(pc);
pc->c[0] = IDETAPE_REQUEST_SENSE_CMD;
pc->c[4] = 20;
pc->request_transfer = 20;
pc->callback = &idetape_request_sense_callback;
}
static void idetape_init_rq(struct request *rq, u8 cmd)
{
memset(rq, 0, sizeof(*rq));
rq->cmd_type = REQ_TYPE_SPECIAL;
rq->cmd[0] = cmd;
}
/*
* idetape_queue_pc_head generates a new packet command request in front
* of the request queue, before the current request, so that it will be
* processed immediately, on the next pass through the driver.
*
* idetape_queue_pc_head is called from the request handling part of
* the driver (the "bottom" part). Safe storage for the request should
* be allocated with idetape_next_pc_storage and idetape_next_rq_storage
* before calling idetape_queue_pc_head.
*
* Memory for those requests is pre-allocated at initialization time, and
* is limited to IDETAPE_PC_STACK requests. We assume that we have enough
* space for the maximum possible number of inter-dependent packet commands.
*
* The higher level of the driver - The ioctl handler and the character
* device handling functions should queue request to the lower level part
* and wait for their completion using idetape_queue_pc_tail or
* idetape_queue_rw_tail.
*/
static void idetape_queue_pc_head (ide_drive_t *drive, idetape_pc_t *pc,struct request *rq)
{
struct ide_tape_obj *tape = drive->driver_data;
idetape_init_rq(rq, REQ_IDETAPE_PC1);
rq->buffer = (char *) pc;
rq->rq_disk = tape->disk;
(void) ide_do_drive_cmd(drive, rq, ide_preempt);
}
/*
* idetape_retry_pc is called when an error was detected during the
* last packet command. We queue a request sense packet command in
* the head of the request list.
*/
static ide_startstop_t idetape_retry_pc (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc;
struct request *rq;
atapi_error_t error;
error.all = HWIF(drive)->INB(IDE_ERROR_REG);
pc = idetape_next_pc_storage(drive);
rq = idetape_next_rq_storage(drive);
idetape_create_request_sense_cmd(pc);
set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
idetape_queue_pc_head(drive, pc, rq);
return ide_stopped;
}
/*
* idetape_postpone_request postpones the current request so that
* ide.c will be able to service requests from another device on
* the same hwgroup while we are polling for DSC.
*/
static void idetape_postpone_request (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: idetape_postpone_request\n");
#endif
tape->postponed_rq = HWGROUP(drive)->rq;
ide_stall_queue(drive, tape->dsc_polling_frequency);
}
/*
* idetape_pc_intr is the usual interrupt handler which will be called
* during a packet command. We will transfer some of the data (as
* requested by the drive) and will re-point interrupt handler to us.
* When data transfer is finished, we will act according to the
* algorithm described before idetape_issue_packet_command.
*
*/
static ide_startstop_t idetape_pc_intr (ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
idetape_tape_t *tape = drive->driver_data;
atapi_status_t status;
atapi_bcount_t bcount;
atapi_ireason_t ireason;
idetape_pc_t *pc = tape->pc;
unsigned int temp;
#if SIMULATE_ERRORS
static int error_sim_count = 0;
#endif
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: Reached idetape_pc_intr "
"interrupt handler\n");
#endif /* IDETAPE_DEBUG_LOG */
/* Clear the interrupt */
status.all = HWIF(drive)->INB(IDE_STATUS_REG);
if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
if (HWIF(drive)->ide_dma_end(drive) || status.b.check) {
/*
* A DMA error is sometimes expected. For example,
* if the tape is crossing a filemark during a
* READ command, it will issue an irq and position
* itself before the filemark, so that only a partial
* data transfer will occur (which causes the DMA
* error). In that case, we will later ask the tape
* how much bytes of the original request were
* actually transferred (we can't receive that
* information from the DMA engine on most chipsets).
*/
/*
* On the contrary, a DMA error is never expected;
* it usually indicates a hardware error or abort.
* If the tape crosses a filemark during a READ
* command, it will issue an irq and position itself
* after the filemark (not before). Only a partial
* data transfer will occur, but no DMA error.
* (AS, 19 Apr 2001)
*/
set_bit(PC_DMA_ERROR, &pc->flags);
} else {
pc->actually_transferred = pc->request_transfer;
idetape_update_buffers(pc);
}
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: DMA finished\n");
#endif /* IDETAPE_DEBUG_LOG */
}
/* No more interrupts */
if (!status.b.drq) {
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 2)
printk(KERN_INFO "ide-tape: Packet command completed, %d bytes transferred\n", pc->actually_transferred);
#endif /* IDETAPE_DEBUG_LOG */
clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);
local_irq_enable();
#if SIMULATE_ERRORS
if ((pc->c[0] == IDETAPE_WRITE_CMD ||
pc->c[0] == IDETAPE_READ_CMD) &&
(++error_sim_count % 100) == 0) {
printk(KERN_INFO "ide-tape: %s: simulating error\n",
tape->name);
status.b.check = 1;
}
#endif
if (status.b.check && pc->c[0] == IDETAPE_REQUEST_SENSE_CMD)
status.b.check = 0;
if (status.b.check || test_bit(PC_DMA_ERROR, &pc->flags)) { /* Error detected */
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 1)
printk(KERN_INFO "ide-tape: %s: I/O error\n",
tape->name);
#endif /* IDETAPE_DEBUG_LOG */
if (pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
printk(KERN_ERR "ide-tape: I/O error in request sense command\n");
return ide_do_reset(drive);
}
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 1)
printk(KERN_INFO "ide-tape: [cmd %x]: check condition\n", pc->c[0]);
#endif
/* Retry operation */
return idetape_retry_pc(drive);
}
pc->error = 0;
if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) &&
!status.b.dsc) {
/* Media access command */
tape->dsc_polling_start = jiffies;
tape->dsc_polling_frequency = IDETAPE_DSC_MA_FAST;
tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
/* Allow ide.c to handle other requests */
idetape_postpone_request(drive);
return ide_stopped;
}
if (tape->failed_pc == pc)
tape->failed_pc = NULL;
/* Command finished - Call the callback function */
return pc->callback(drive);
}
if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
printk(KERN_ERR "ide-tape: The tape wants to issue more "
"interrupts in DMA mode\n");
printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n");
ide_dma_off(drive);
return ide_do_reset(drive);
}
/* Get the number of bytes to transfer on this interrupt. */
bcount.b.high = hwif->INB(IDE_BCOUNTH_REG);
bcount.b.low = hwif->INB(IDE_BCOUNTL_REG);
ireason.all = hwif->INB(IDE_IREASON_REG);
if (ireason.b.cod) {
printk(KERN_ERR "ide-tape: CoD != 0 in idetape_pc_intr\n");
return ide_do_reset(drive);
}
if (ireason.b.io == test_bit(PC_WRITING, &pc->flags)) {
/* Hopefully, we will never get here */
printk(KERN_ERR "ide-tape: We wanted to %s, ",
ireason.b.io ? "Write":"Read");
printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n",
ireason.b.io ? "Read":"Write");
return ide_do_reset(drive);
}
if (!test_bit(PC_WRITING, &pc->flags)) {
/* Reading - Check that we have enough space */
temp = pc->actually_transferred + bcount.all;
if (temp > pc->request_transfer) {
if (temp > pc->buffer_size) {
printk(KERN_ERR "ide-tape: The tape wants to send us more data than expected - discarding data\n");
idetape_discard_data(drive, bcount.all);
ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
return ide_started;
}
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 2)
printk(KERN_NOTICE "ide-tape: The tape wants to send us more data than expected - allowing transfer\n");
#endif /* IDETAPE_DEBUG_LOG */
}
}
if (test_bit(PC_WRITING, &pc->flags)) {
if (pc->bh != NULL)
idetape_output_buffers(drive, pc, bcount.all);
else
/* Write the current buffer */
HWIF(drive)->atapi_output_bytes(drive, pc->current_position, bcount.all);
} else {
if (pc->bh != NULL)
idetape_input_buffers(drive, pc, bcount.all);
else
/* Read the current buffer */
HWIF(drive)->atapi_input_bytes(drive, pc->current_position, bcount.all);
}
/* Update the current position */
pc->actually_transferred += bcount.all;
pc->current_position += bcount.all;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 2)
printk(KERN_INFO "ide-tape: [cmd %x] transferred %d bytes on that interrupt\n", pc->c[0], bcount.all);
#endif
/* And set the interrupt handler again */
ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
return ide_started;
}
/*
* Packet Command Interface
*
* The current Packet Command is available in tape->pc, and will not
* change until we finish handling it. Each packet command is associated
* with a callback function that will be called when the command is
* finished.
*
* The handling will be done in three stages:
*
* 1. idetape_issue_packet_command will send the packet command to the
* drive, and will set the interrupt handler to idetape_pc_intr.
*
* 2. On each interrupt, idetape_pc_intr will be called. This step
* will be repeated until the device signals us that no more
* interrupts will be issued.
*
* 3. ATAPI Tape media access commands have immediate status with a
* delayed process. In case of a successful initiation of a
* media access packet command, the DSC bit will be set when the
* actual execution of the command is finished.
* Since the tape drive will not issue an interrupt, we have to
* poll for this event. In this case, we define the request as
* "low priority request" by setting rq_status to
* IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and exit
* the driver.
*
* ide.c will then give higher priority to requests which
* originate from the other device, until will change rq_status
* to RQ_ACTIVE.
*
* 4. When the packet command is finished, it will be checked for errors.
*
* 5. In case an error was found, we queue a request sense packet
* command in front of the request queue and retry the operation
* up to IDETAPE_MAX_PC_RETRIES times.
*
* 6. In case no error was found, or we decided to give up and not
* to retry again, the callback function will be called and then
* we will handle the next request.
*
*/
static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc = tape->pc;
atapi_ireason_t ireason;
int retries = 100;
ide_startstop_t startstop;
if (ide_wait_stat(&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
printk(KERN_ERR "ide-tape: Strange, packet command initiated yet DRQ isn't asserted\n");
return startstop;
}
ireason.all = hwif->INB(IDE_IREASON_REG);
while (retries-- && (!ireason.b.cod || ireason.b.io)) {
printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing "
"a packet command, retrying\n");
udelay(100);
ireason.all = hwif->INB(IDE_IREASON_REG);
if (retries == 0) {
printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while "
"issuing a packet command, ignoring\n");
ireason.b.cod = 1;
ireason.b.io = 0;
}
}
if (!ireason.b.cod || ireason.b.io) {
printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing "
"a packet command\n");
return ide_do_reset(drive);
}
/* Set the interrupt routine */
ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
#ifdef CONFIG_BLK_DEV_IDEDMA
/* Begin DMA, if necessary */
if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags))
hwif->dma_start(drive);
#endif
/* Send the actual packet */
HWIF(drive)->atapi_output_bytes(drive, pc->c, 12);
return ide_started;
}
static ide_startstop_t idetape_issue_packet_command (ide_drive_t *drive, idetape_pc_t *pc)
{
ide_hwif_t *hwif = drive->hwif;
idetape_tape_t *tape = drive->driver_data;
atapi_bcount_t bcount;
int dma_ok = 0;
#if IDETAPE_DEBUG_BUGS
if (tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD &&
pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
printk(KERN_ERR "ide-tape: possible ide-tape.c bug - "
"Two request sense in serial were issued\n");
}
#endif /* IDETAPE_DEBUG_BUGS */
if (tape->failed_pc == NULL && pc->c[0] != IDETAPE_REQUEST_SENSE_CMD)
tape->failed_pc = pc;
/* Set the current packet command */
tape->pc = pc;
if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
test_bit(PC_ABORT, &pc->flags)) {
/*
* We will "abort" retrying a packet command in case
* a legitimate error code was received (crossing a
* filemark, or end of the media, for example).
*/
if (!test_bit(PC_ABORT, &pc->flags)) {
if (!(pc->c[0] == IDETAPE_TEST_UNIT_READY_CMD &&
tape->sense_key == 2 && tape->asc == 4 &&
(tape->ascq == 1 || tape->ascq == 8))) {
printk(KERN_ERR "ide-tape: %s: I/O error, "
"pc = %2x, key = %2x, "
"asc = %2x, ascq = %2x\n",
tape->name, pc->c[0],
tape->sense_key, tape->asc,
tape->ascq);
}
/* Giving up */
pc->error = IDETAPE_ERROR_GENERAL;
}
tape->failed_pc = NULL;
return pc->callback(drive);
}
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 2)
printk(KERN_INFO "ide-tape: Retry number - %d, cmd = %02X\n", pc->retries, pc->c[0]);
#endif /* IDETAPE_DEBUG_LOG */
pc->retries++;
/* We haven't transferred any data yet */
pc->actually_transferred = 0;
pc->current_position = pc->buffer;
/* Request to transfer the entire buffer at once */
bcount.all = pc->request_transfer;
if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) {
printk(KERN_WARNING "ide-tape: DMA disabled, "
"reverting to PIO\n");
ide_dma_off(drive);
}
if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma)
dma_ok = !hwif->dma_setup(drive);
if (IDE_CONTROL_REG)
hwif->OUTB(drive->ctl, IDE_CONTROL_REG);
hwif->OUTB(dma_ok ? 1 : 0, IDE_FEATURE_REG); /* Use PIO/DMA */
hwif->OUTB(bcount.b.high, IDE_BCOUNTH_REG);
hwif->OUTB(bcount.b.low, IDE_BCOUNTL_REG);
hwif->OUTB(drive->select.all, IDE_SELECT_REG);
if (dma_ok) /* Will begin DMA later */
set_bit(PC_DMA_IN_PROGRESS, &pc->flags);
if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) {
ide_set_handler(drive, &idetape_transfer_pc, IDETAPE_WAIT_CMD, NULL);
hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
return ide_started;
} else {
hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
return idetape_transfer_pc(drive);
}
}
/*
* General packet command callback function.
*/
static ide_startstop_t idetape_pc_callback (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: Reached idetape_pc_callback\n");
#endif /* IDETAPE_DEBUG_LOG */
idetape_end_request(drive, tape->pc->error ? 0 : 1, 0);
return ide_stopped;
}
/*
* A mode sense command is used to "sense" tape parameters.
*/
static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, u8 page_code)
{
idetape_init_pc(pc);
pc->c[0] = IDETAPE_MODE_SENSE_CMD;
if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
pc->c[1] = 8; /* DBD = 1 - Don't return block descriptors */
pc->c[2] = page_code;
/*
* Changed pc->c[3] to 0 (255 will at best return unused info).
*
* For SCSI this byte is defined as subpage instead of high byte
* of length and some IDE drives seem to interpret it this way
* and return an error when 255 is used.
*/
pc->c[3] = 0;
pc->c[4] = 255; /* (We will just discard data in that case) */
if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
pc->request_transfer = 12;
else if (page_code == IDETAPE_CAPABILITIES_PAGE)
pc->request_transfer = 24;
else
pc->request_transfer = 50;
pc->callback = &idetape_pc_callback;
}
static void calculate_speeds(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
int full = 125, empty = 75;
if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) {
tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head;
tape->controlled_previous_head_time = tape->controlled_pipeline_head_time;
tape->controlled_last_pipeline_head = tape->pipeline_head;
tape->controlled_pipeline_head_time = jiffies;
}
if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time);
else if (time_after(jiffies, tape->controlled_previous_head_time))
tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time);
if (tape->nr_pending_stages < tape->max_stages /*- 1 */) {
/* -1 for read mode error recovery */
if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) {
tape->uncontrolled_pipeline_head_time = jiffies;
tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time);
}
} else {
tape->uncontrolled_previous_head_time = jiffies;
tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) {
tape->uncontrolled_pipeline_head_time = jiffies;
}
}
tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed, tape->controlled_pipeline_head_speed);
if (tape->speed_control == 0) {
tape->max_insert_speed = 5000;
} else if (tape->speed_control == 1) {
if (tape->nr_pending_stages >= tape->max_stages / 2)
tape->max_insert_speed = tape->pipeline_head_speed +
(1100 - tape->pipeline_head_speed) * 2 * (tape->nr_pending_stages - tape->max_stages / 2) / tape->max_stages;
else
tape->max_insert_speed = 500 +
(tape->pipeline_head_speed - 500) * 2 * tape->nr_pending_stages / tape->max_stages;
if (tape->nr_pending_stages >= tape->max_stages * 99 / 100)
tape->max_insert_speed = 5000;
} else if (tape->speed_control == 2) {
tape->max_insert_speed = tape->pipeline_head_speed * empty / 100 +
(tape->pipeline_head_speed * full / 100 - tape->pipeline_head_speed * empty / 100) * tape->nr_pending_stages / tape->max_stages;
} else
tape->max_insert_speed = tape->speed_control;
tape->max_insert_speed = max(tape->max_insert_speed, 500);
}
static ide_startstop_t idetape_media_access_finished (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc = tape->pc;
atapi_status_t status;
status.all = HWIF(drive)->INB(IDE_STATUS_REG);
if (status.b.dsc) {
if (status.b.check) {
/* Error detected */
if (pc->c[0] != IDETAPE_TEST_UNIT_READY_CMD)
printk(KERN_ERR "ide-tape: %s: I/O error, ",
tape->name);
/* Retry operation */
return idetape_retry_pc(drive);
}
pc->error = 0;
if (tape->failed_pc == pc)
tape->failed_pc = NULL;
} else {
pc->error = IDETAPE_ERROR_GENERAL;
tape->failed_pc = NULL;
}
return pc->callback(drive);
}
static ide_startstop_t idetape_rw_callback (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
struct request *rq = HWGROUP(drive)->rq;
int blocks = tape->pc->actually_transferred / tape->tape_block_size;
tape->avg_size += blocks * tape->tape_block_size;
tape->insert_size += blocks * tape->tape_block_size;
if (tape->insert_size > 1024 * 1024)
tape->measure_insert_time = 1;
if (tape->measure_insert_time) {
tape->measure_insert_time = 0;
tape->insert_time = jiffies;
tape->insert_size = 0;
}
if (time_after(jiffies, tape->insert_time))
tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
if (time_after_eq(jiffies, tape->avg_time + HZ)) {
tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024;
tape->avg_size = 0;
tape->avg_time = jiffies;
}
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: Reached idetape_rw_callback\n");
#endif /* IDETAPE_DEBUG_LOG */
tape->first_frame_position += blocks;
rq->current_nr_sectors -= blocks;
if (!tape->pc->error)
idetape_end_request(drive, 1, 0);
else
idetape_end_request(drive, tape->pc->error, 0);
return ide_stopped;
}
static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
{
idetape_init_pc(pc);
pc->c[0] = IDETAPE_READ_CMD;
put_unaligned(htonl(length), (unsigned int *) &pc->c[1]);
pc->c[1] = 1;
pc->callback = &idetape_rw_callback;
pc->bh = bh;
atomic_set(&bh->b_count, 0);
pc->buffer = NULL;
pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
if (pc->request_transfer == tape->stage_size)
set_bit(PC_DMA_RECOMMENDED, &pc->flags);
}
static void idetape_create_read_buffer_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
{
int size = 32768;
struct idetape_bh *p = bh;
idetape_init_pc(pc);
pc->c[0] = IDETAPE_READ_BUFFER_CMD;
pc->c[1] = IDETAPE_RETRIEVE_FAULTY_BLOCK;
pc->c[7] = size >> 8;
pc->c[8] = size & 0xff;
pc->callback = &idetape_pc_callback;
pc->bh = bh;
atomic_set(&bh->b_count, 0);
pc->buffer = NULL;
while (p) {
atomic_set(&p->b_count, 0);
p = p->b_reqnext;
}
pc->request_transfer = pc->buffer_size = size;
}
static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
{
idetape_init_pc(pc);
pc->c[0] = IDETAPE_WRITE_CMD;
put_unaligned(htonl(length), (unsigned int *) &pc->c[1]);
pc->c[1] = 1;
pc->callback = &idetape_rw_callback;
set_bit(PC_WRITING, &pc->flags);
pc->bh = bh;
pc->b_data = bh->b_data;
pc->b_count = atomic_read(&bh->b_count);
pc->buffer = NULL;
pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
if (pc->request_transfer == tape->stage_size)
set_bit(PC_DMA_RECOMMENDED, &pc->flags);
}
/*
* idetape_do_request is our request handling function.
*/
static ide_startstop_t idetape_do_request(ide_drive_t *drive,
struct request *rq, sector_t block)
{
idetape_tape_t *tape = drive->driver_data;
idetape_pc_t *pc = NULL;
struct request *postponed_rq = tape->postponed_rq;
atapi_status_t status;
#if IDETAPE_DEBUG_LOG
#if 0
if (tape->debug_level >= 5)
printk(KERN_INFO "ide-tape: %d, "
"dev: %s, cmd: %ld, errors: %d\n",
rq->rq_disk->disk_name, rq->cmd[0], rq->errors);
#endif
if (tape->debug_level >= 2)
printk(KERN_INFO "ide-tape: sector: %ld, "
"nr_sectors: %ld, current_nr_sectors: %d\n",
rq->sector, rq->nr_sectors, rq->current_nr_sectors);
#endif /* IDETAPE_DEBUG_LOG */
if (!blk_special_request(rq)) {
/*
* We do not support buffer cache originated requests.
*/
printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
"request queue (%d)\n", drive->name, rq->cmd_type);
ide_end_request(drive, 0, 0);
return ide_stopped;
}
/*
* Retry a failed packet command
*/
if (tape->failed_pc != NULL &&
tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
return idetape_issue_packet_command(drive, tape->failed_pc);
}
#if IDETAPE_DEBUG_BUGS
if (postponed_rq != NULL)
if (rq != postponed_rq) {
printk(KERN_ERR "ide-tape: ide-tape.c bug - "
"Two DSC requests were queued\n");
idetape_end_request(drive, 0, 0);
return ide_stopped;
}
#endif /* IDETAPE_DEBUG_BUGS */
tape->postponed_rq = NULL;
/*
* If the tape is still busy, postpone our request and service
* the other device meanwhile.
*/
status.all = HWIF(drive)->INB(IDE_STATUS_REG);
if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2))
set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
if (drive->post_reset == 1) {
set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
drive->post_reset = 0;
}
if (tape->tape_still_time > 100 && tape->tape_still_time < 200)
tape->measure_insert_time = 1;
if (time_after(jiffies, tape->insert_time))
tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
calculate_speeds(drive);
if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) &&
!status.b.dsc) {
if (postponed_rq == NULL) {
tape->dsc_polling_start = jiffies;
tape->dsc_polling_frequency = tape->best_dsc_rw_frequency;
tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
} else if (time_after(jiffies, tape->dsc_timeout)) {
printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
tape->name);
if (rq->cmd[0] & REQ_IDETAPE_PC2) {
idetape_media_access_finished(drive);
return ide_stopped;
} else {
return ide_do_reset(drive);
}
} else if (time_after(jiffies, tape->dsc_polling_start + IDETAPE_DSC_MA_THRESHOLD))
tape->dsc_polling_frequency = IDETAPE_DSC_MA_SLOW;
idetape_postpone_request(drive);
return ide_stopped;
}
if (rq->cmd[0] & REQ_IDETAPE_READ) {
tape->buffer_head++;
#if USE_IOTRACE
IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
#endif
tape->postpone_cnt = 0;
pc = idetape_next_pc_storage(drive);
idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
goto out;
}
if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
tape->buffer_head++;
#if USE_IOTRACE
IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
#endif
tape->postpone_cnt = 0;
pc = idetape_next_pc_storage(drive);
idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
goto out;
}
if (rq->cmd[0] & REQ_IDETAPE_READ_BUFFER) {
tape->postpone_cnt = 0;
pc = idetape_next_pc_storage(drive);
idetape_create_read_buffer_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
goto out;
}
if (rq->cmd[0] & REQ_IDETAPE_PC1) {
pc = (idetape_pc_t *) rq->buffer;
rq->cmd[0] &= ~(REQ_IDETAPE_PC1);
rq->cmd[0] |= REQ_IDETAPE_PC2;
goto out;
}
if (rq->cmd[0] & REQ_IDETAPE_PC2) {
idetape_media_access_finished(drive);
return ide_stopped;
}
BUG();
out:
return idetape_issue_packet_command(drive, pc);
}
/*
* Pipeline related functions
*/
static inline int idetape_pipeline_active (idetape_tape_t *tape)
{
int rc1, rc2;
rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
rc2 = (tape->active_data_request != NULL);
return rc1;
}
/*
* idetape_kmalloc_stage uses __get_free_page to allocate a pipeline
* stage, along with all the necessary small buffers which together make
* a buffer of size tape->stage_size (or a bit more). We attempt to
* combine sequential pages as much as possible.
*
* Returns a pointer to the new allocated stage, or NULL if we
* can't (or don't want to) allocate a stage.
*
* Pipeline stages are optional and are used to increase performance.
* If we can't allocate them, we'll manage without them.
*/
static idetape_stage_t *__idetape_kmalloc_stage (idetape_tape_t *tape, int full, int clear)
{
idetape_stage_t *stage;
struct idetape_bh *prev_bh, *bh;
int pages = tape->pages_per_stage;
char *b_data = NULL;
if ((stage = kmalloc(sizeof (idetape_stage_t),GFP_KERNEL)) == NULL)
return NULL;
stage->next = NULL;
bh = stage->bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
if (bh == NULL)
goto abort;
bh->b_reqnext = NULL;
if ((bh->b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
goto abort;
if (clear)
memset(bh->b_data, 0, PAGE_SIZE);
bh->b_size = PAGE_SIZE;
atomic_set(&bh->b_count, full ? bh->b_size : 0);
while (--pages) {
if ((b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
goto abort;
if (clear)
memset(b_data, 0, PAGE_SIZE);
if (bh->b_data == b_data + PAGE_SIZE) {
bh->b_size += PAGE_SIZE;
bh->b_data -= PAGE_SIZE;
if (full)
atomic_add(PAGE_SIZE, &bh->b_count);
continue;
}
if (b_data == bh->b_data + bh->b_size) {
bh->b_size += PAGE_SIZE;
if (full)
atomic_add(PAGE_SIZE, &bh->b_count);
continue;
}
prev_bh = bh;
if ((bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL)) == NULL) {
free_page((unsigned long) b_data);
goto abort;
}
bh->b_reqnext = NULL;
bh->b_data = b_data;
bh->b_size = PAGE_SIZE;
atomic_set(&bh->b_count, full ? bh->b_size : 0);
prev_bh->b_reqnext = bh;
}
bh->b_size -= tape->excess_bh_size;
if (full)
atomic_sub(tape->excess_bh_size, &bh->b_count);
return stage;
abort:
__idetape_kfree_stage(stage);
return NULL;
}
static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape)
{
idetape_stage_t *cache_stage = tape->cache_stage;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: Reached idetape_kmalloc_stage\n");
#endif /* IDETAPE_DEBUG_LOG */
if (tape->nr_stages >= tape->max_stages)
return NULL;
if (cache_stage != NULL) {
tape->cache_stage = NULL;
return cache_stage;
}
return __idetape_kmalloc_stage(tape, 0, 0);
}
static int idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)
{
struct idetape_bh *bh = tape->bh;
int count;
int ret = 0;
while (n) {
#if IDETAPE_DEBUG_BUGS
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_copy_stage_from_user\n");
return 1;
}
#endif /* IDETAPE_DEBUG_BUGS */
count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);
if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count))
ret = 1;
n -= count;
atomic_add(count, &bh->b_count);
buf += count;
if (atomic_read(&bh->b_count) == bh->b_size) {
bh = bh->b_reqnext;
if (bh)
atomic_set(&bh->b_count, 0);
}
}
tape->bh = bh;
return ret;
}
static int idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
{
struct idetape_bh *bh = tape->bh;
int count;
int ret = 0;
while (n) {
#if IDETAPE_DEBUG_BUGS
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_copy_stage_to_user\n");
return 1;
}
#endif /* IDETAPE_DEBUG_BUGS */
count = min(tape->b_count, n);
if (copy_to_user(buf, tape->b_data, count))
ret = 1;
n -= count;
tape->b_data += count;
tape->b_count -= count;
buf += count;
if (!tape->b_count) {
tape->bh = bh = bh->b_reqnext;
if (bh) {
tape->b_data = bh->b_data;
tape->b_count = atomic_read(&bh->b_count);
}
}
}
return ret;
}
static void idetape_init_merge_stage (idetape_tape_t *tape)
{
struct idetape_bh *bh = tape->merge_stage->bh;
tape->bh = bh;
if (tape->chrdev_direction == idetape_direction_write)
atomic_set(&bh->b_count, 0);
else {
tape->b_data = bh->b_data;
tape->b_count = atomic_read(&bh->b_count);
}
}
static void idetape_switch_buffers (idetape_tape_t *tape, idetape_stage_t *stage)
{
struct idetape_bh *tmp;
tmp = stage->bh;
stage->bh = tape->merge_stage->bh;
tape->merge_stage->bh = tmp;
idetape_init_merge_stage(tape);
}
/*
* idetape_add_stage_tail adds a new stage at the end of the pipeline.
*/
static void idetape_add_stage_tail (ide_drive_t *drive,idetape_stage_t *stage)
{
idetape_tape_t *tape = drive->driver_data;
unsigned long flags;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk (KERN_INFO "ide-tape: Reached idetape_add_stage_tail\n");
#endif /* IDETAPE_DEBUG_LOG */
spin_lock_irqsave(&tape->spinlock, flags);
stage->next = NULL;
if (tape->last_stage != NULL)
tape->last_stage->next=stage;
else
tape->first_stage = tape->next_stage=stage;
tape->last_stage = stage;
if (tape->next_stage == NULL)
tape->next_stage = tape->last_stage;
tape->nr_stages++;
tape->nr_pending_stages++;
spin_unlock_irqrestore(&tape->spinlock, flags);
}
/*
* idetape_wait_for_request installs a completion in a pending request
* and sleeps until it is serviced.
*
* The caller should ensure that the request will not be serviced
* before we install the completion (usually by disabling interrupts).
*/
static void idetape_wait_for_request (ide_drive_t *drive, struct request *rq)
{
DECLARE_COMPLETION_ONSTACK(wait);
idetape_tape_t *tape = drive->driver_data;
#if IDETAPE_DEBUG_BUGS
if (rq == NULL || !blk_special_request(rq)) {
printk (KERN_ERR "ide-tape: bug: Trying to sleep on non-valid request\n");
return;
}
#endif /* IDETAPE_DEBUG_BUGS */
rq->end_io_data = &wait;
rq->end_io = blk_end_sync_rq;
spin_unlock_irq(&tape->spinlock);
wait_for_completion(&wait);
/* The stage and its struct request have been deallocated */
spin_lock_irq(&tape->spinlock);
}
static ide_startstop_t idetape_read_position_callback (ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
idetape_read_position_result_t *result;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 4)
printk(KERN_INFO "ide-tape: Reached idetape_read_position_callback\n");
#endif /* IDETAPE_DEBUG_LOG */
if (!tape->pc->error) {
result = (idetape_read_position_result_t *) tape->pc->buffer;
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 2)
printk(KERN_INFO "ide-tape: BOP - %s\n",result->bop ? "Yes":"No");
if (tape->debug_level >= 2)
printk(KERN_INFO "ide-tape: EOP - %s\n",result->eop ? "Yes":"No");
#endif /* IDETAPE_DEBUG_LOG */
if (result->bpu) {
printk(KERN_INFO "ide-tape: Block location is unknown to the tape\n");
clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
idetape_end_request(drive, 0, 0);
} else {
#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 2)
printk(KERN_INFO "ide-tape: Block Location - %u\n", ntohl(result->first_block));
#endif /* IDETAPE_DEBUG_LOG */
tape->partition = result->partition;
tape->first_frame_position = ntohl(result->first_block);
tape->last_frame_position = ntohl(result->last_block);
tape->blocks_in_buffer = result->blocks_in_buffer[2];
set_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
idetape_end_request(drive, 1, 0);
}
} else {
idetape_end_request(drive, 0, 0);
}
return ide_stopped;
}
/*
* idetape_create_write_filemark_cmd will:
*
* 1. Write a filemark if write_filemark=1.
* 2. Flush the device buffers without writing a filemark
* if write_filemark=0.
*
*/
static void idetape_create_write_filemark_cmd (ide_drive_t *drive, idetape_pc_t *pc,int write_filemark)
{
idetape_init_pc(pc);
pc->c[0] = IDETAPE_WRITE_FILEMARK_CMD;
pc->c[4] = write_filemark;
set_bit(PC_WAIT_FOR_DSC, &pc->flags);
pc->callback =