| /* |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License version 2 |
| * as published by the Free Software Foundation; or, when distributed |
| * separately from the Linux kernel or incorporated into other |
| * software packages, subject to the following license: |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this source file (the "Software"), to deal in the Software without |
| * restriction, including without limitation the rights to use, copy, modify, |
| * merge, publish, distribute, sublicense, and/or sell copies of the Software, |
| * and to permit persons to whom the Software is furnished to do so, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| */ |
| |
| #ifndef __XEN_BLKIF__BACKEND__COMMON_H__ |
| #define __XEN_BLKIF__BACKEND__COMMON_H__ |
| |
| #include <linux/module.h> |
| #include <linux/interrupt.h> |
| #include <linux/slab.h> |
| #include <linux/blkdev.h> |
| #include <linux/vmalloc.h> |
| #include <linux/wait.h> |
| #include <linux/io.h> |
| #include <asm/setup.h> |
| #include <asm/pgalloc.h> |
| #include <asm/hypervisor.h> |
| #include <xen/grant_table.h> |
| #include <xen/xenbus.h> |
| #include <xen/interface/io/ring.h> |
| #include <xen/interface/io/blkif.h> |
| #include <xen/interface/io/protocols.h> |
| |
| #define DRV_PFX "xen-blkback:" |
| #define DPRINTK(fmt, args...) \ |
| pr_debug(DRV_PFX "(%s:%d) " fmt ".\n", \ |
| __func__, __LINE__, ##args) |
| |
| |
| /* Not a real protocol. Used to generate ring structs which contain |
| * the elements common to all protocols only. This way we get a |
| * compiler-checkable way to use common struct elements, so we can |
| * avoid using switch(protocol) in a number of places. */ |
| struct blkif_common_request { |
| char dummy; |
| }; |
| struct blkif_common_response { |
| char dummy; |
| }; |
| |
| /* i386 protocol version */ |
| #pragma pack(push, 4) |
| |
| struct blkif_x86_32_request_rw { |
| blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ |
| struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
| }; |
| |
| struct blkif_x86_32_request_discard { |
| blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ |
| uint64_t nr_sectors; |
| }; |
| |
| struct blkif_x86_32_request { |
| uint8_t operation; /* BLKIF_OP_??? */ |
| uint8_t nr_segments; /* number of segments */ |
| blkif_vdev_t handle; /* only for read/write requests */ |
| uint64_t id; /* private guest value, echoed in resp */ |
| union { |
| struct blkif_x86_32_request_rw rw; |
| struct blkif_x86_32_request_discard discard; |
| } u; |
| }; |
| struct blkif_x86_32_response { |
| uint64_t id; /* copied from request */ |
| uint8_t operation; /* copied from request */ |
| int16_t status; /* BLKIF_RSP_??? */ |
| }; |
| #pragma pack(pop) |
| |
| /* x86_64 protocol version */ |
| |
| struct blkif_x86_64_request_rw { |
| blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ |
| struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
| }; |
| |
| struct blkif_x86_64_request_discard { |
| blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ |
| uint64_t nr_sectors; |
| }; |
| |
| struct blkif_x86_64_request { |
| uint8_t operation; /* BLKIF_OP_??? */ |
| uint8_t nr_segments; /* number of segments */ |
| blkif_vdev_t handle; /* only for read/write requests */ |
| uint64_t __attribute__((__aligned__(8))) id; |
| union { |
| struct blkif_x86_64_request_rw rw; |
| struct blkif_x86_64_request_discard discard; |
| } u; |
| }; |
| struct blkif_x86_64_response { |
| uint64_t __attribute__((__aligned__(8))) id; |
| uint8_t operation; /* copied from request */ |
| int16_t status; /* BLKIF_RSP_??? */ |
| }; |
| |
| DEFINE_RING_TYPES(blkif_common, struct blkif_common_request, |
| struct blkif_common_response); |
| DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request, |
| struct blkif_x86_32_response); |
| DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request, |
| struct blkif_x86_64_response); |
| |
| union blkif_back_rings { |
| struct blkif_back_ring native; |
| struct blkif_common_back_ring common; |
| struct blkif_x86_32_back_ring x86_32; |
| struct blkif_x86_64_back_ring x86_64; |
| }; |
| |
| enum blkif_protocol { |
| BLKIF_PROTOCOL_NATIVE = 1, |
| BLKIF_PROTOCOL_X86_32 = 2, |
| BLKIF_PROTOCOL_X86_64 = 3, |
| }; |
| |
| enum blkif_backend_type { |
| BLKIF_BACKEND_PHY = 1, |
| BLKIF_BACKEND_FILE = 2, |
| }; |
| |
| struct xen_vbd { |
| /* What the domain refers to this vbd as. */ |
| blkif_vdev_t handle; |
| /* Non-zero -> read-only */ |
| unsigned char readonly; |
| /* VDISK_xxx */ |
| unsigned char type; |
| /* phys device that this vbd maps to. */ |
| u32 pdevice; |
| struct block_device *bdev; |
| /* Cached size parameter. */ |
| sector_t size; |
| bool flush_support; |
| }; |
| |
| struct backend_info; |
| |
| struct xen_blkif { |
| /* Unique identifier for this interface. */ |
| domid_t domid; |
| unsigned int handle; |
| /* Physical parameters of the comms window. */ |
| unsigned int irq; |
| /* Comms information. */ |
| enum blkif_protocol blk_protocol; |
| enum blkif_backend_type blk_backend_type; |
| union blkif_back_rings blk_rings; |
| struct vm_struct *blk_ring_area; |
| /* The VBD attached to this interface. */ |
| struct xen_vbd vbd; |
| /* Back pointer to the backend_info. */ |
| struct backend_info *be; |
| /* Private fields. */ |
| spinlock_t blk_ring_lock; |
| atomic_t refcnt; |
| |
| wait_queue_head_t wq; |
| /* for barrier (drain) requests */ |
| struct completion drain_complete; |
| atomic_t drain; |
| /* One thread per one blkif. */ |
| struct task_struct *xenblkd; |
| unsigned int waiting_reqs; |
| |
| /* statistics */ |
| unsigned long st_print; |
| int st_rd_req; |
| int st_wr_req; |
| int st_oo_req; |
| int st_f_req; |
| int st_ds_req; |
| int st_rd_sect; |
| int st_wr_sect; |
| |
| wait_queue_head_t waiting_to_free; |
| |
| grant_handle_t shmem_handle; |
| grant_ref_t shmem_ref; |
| }; |
| |
| |
| #define vbd_sz(_v) ((_v)->bdev->bd_part ? \ |
| (_v)->bdev->bd_part->nr_sects : \ |
| get_capacity((_v)->bdev->bd_disk)) |
| |
| #define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt)) |
| #define xen_blkif_put(_b) \ |
| do { \ |
| if (atomic_dec_and_test(&(_b)->refcnt)) \ |
| wake_up(&(_b)->waiting_to_free);\ |
| } while (0) |
| |
| struct phys_req { |
| unsigned short dev; |
| blkif_sector_t nr_sects; |
| struct block_device *bdev; |
| blkif_sector_t sector_number; |
| }; |
| int xen_blkif_interface_init(void); |
| |
| int xen_blkif_xenbus_init(void); |
| |
| irqreturn_t xen_blkif_be_int(int irq, void *dev_id); |
| int xen_blkif_schedule(void *arg); |
| |
| int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt, |
| struct backend_info *be, int state); |
| |
| int xen_blkbk_barrier(struct xenbus_transaction xbt, |
| struct backend_info *be, int state); |
| struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be); |
| |
| static inline void blkif_get_x86_32_req(struct blkif_request *dst, |
| struct blkif_x86_32_request *src) |
| { |
| int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST; |
| dst->operation = src->operation; |
| dst->nr_segments = src->nr_segments; |
| dst->handle = src->handle; |
| dst->id = src->id; |
| switch (src->operation) { |
| case BLKIF_OP_READ: |
| case BLKIF_OP_WRITE: |
| case BLKIF_OP_WRITE_BARRIER: |
| case BLKIF_OP_FLUSH_DISKCACHE: |
| dst->u.rw.sector_number = src->u.rw.sector_number; |
| barrier(); |
| if (n > dst->nr_segments) |
| n = dst->nr_segments; |
| for (i = 0; i < n; i++) |
| dst->u.rw.seg[i] = src->u.rw.seg[i]; |
| break; |
| case BLKIF_OP_DISCARD: |
| dst->u.discard.sector_number = src->u.discard.sector_number; |
| dst->u.discard.nr_sectors = src->u.discard.nr_sectors; |
| break; |
| default: |
| break; |
| } |
| } |
| |
| static inline void blkif_get_x86_64_req(struct blkif_request *dst, |
| struct blkif_x86_64_request *src) |
| { |
| int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST; |
| dst->operation = src->operation; |
| dst->nr_segments = src->nr_segments; |
| dst->handle = src->handle; |
| dst->id = src->id; |
| switch (src->operation) { |
| case BLKIF_OP_READ: |
| case BLKIF_OP_WRITE: |
| case BLKIF_OP_WRITE_BARRIER: |
| case BLKIF_OP_FLUSH_DISKCACHE: |
| dst->u.rw.sector_number = src->u.rw.sector_number; |
| barrier(); |
| if (n > dst->nr_segments) |
| n = dst->nr_segments; |
| for (i = 0; i < n; i++) |
| dst->u.rw.seg[i] = src->u.rw.seg[i]; |
| break; |
| case BLKIF_OP_DISCARD: |
| dst->u.discard.sector_number = src->u.discard.sector_number; |
| dst->u.discard.nr_sectors = src->u.discard.nr_sectors; |
| break; |
| default: |
| break; |
| } |
| } |
| |
| #endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */ |