blob: 9cddc1288059018f4f6b3ac2a6cc39ac89af95af [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* channel program interfaces
*
* Copyright IBM Corp. 2017
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
*/
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/iommu.h>
#include <linux/vfio.h>
#include <asm/idals.h>
#include "vfio_ccw_cp.h"
struct pfn_array {
/* Starting guest physical I/O address. */
unsigned long pa_iova;
/* Array that stores PFNs of the pages need to pin. */
unsigned long *pa_iova_pfn;
/* Array that receives PFNs of the pages pinned. */
unsigned long *pa_pfn;
/* Number of pages pinned from @pa_iova. */
int pa_nr;
};
struct ccwchain {
struct list_head next;
struct ccw1 *ch_ccw;
/* Guest physical address of the current chain. */
u64 ch_iova;
/* Count of the valid ccws in chain. */
int ch_len;
/* Pinned PAGEs for the original data. */
struct pfn_array *ch_pa;
};
/*
* pfn_array_alloc() - alloc memory for PFNs
* @pa: pfn_array on which to perform the operation
* @iova: target guest physical address
* @len: number of bytes that should be pinned from @iova
*
* Attempt to allocate memory for PFNs.
*
* Usage of pfn_array:
* We expect (pa_nr == 0) and (pa_iova_pfn == NULL), any field in
* this structure will be filled in by this function.
*
* Returns:
* 0 if PFNs are allocated
* -EINVAL if pa->pa_nr is not initially zero, or pa->pa_iova_pfn is not NULL
* -ENOMEM if alloc failed
*/
static int pfn_array_alloc(struct pfn_array *pa, u64 iova, unsigned int len)
{
int i;
if (pa->pa_nr || pa->pa_iova_pfn)
return -EINVAL;
pa->pa_iova = iova;
pa->pa_nr = ((iova & ~PAGE_MASK) + len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
if (!pa->pa_nr)
return -EINVAL;
pa->pa_iova_pfn = kcalloc(pa->pa_nr,
sizeof(*pa->pa_iova_pfn) +
sizeof(*pa->pa_pfn),
GFP_KERNEL);
if (unlikely(!pa->pa_iova_pfn))
return -ENOMEM;
pa->pa_pfn = pa->pa_iova_pfn + pa->pa_nr;
pa->pa_iova_pfn[0] = pa->pa_iova >> PAGE_SHIFT;
pa->pa_pfn[0] = -1ULL;
for (i = 1; i < pa->pa_nr; i++) {
pa->pa_iova_pfn[i] = pa->pa_iova_pfn[i - 1] + 1;
pa->pa_pfn[i] = -1ULL;
}
return 0;
}
/*
* pfn_array_pin() - Pin user pages in memory
* @pa: pfn_array on which to perform the operation
* @mdev: the mediated device to perform pin operations
*
* Returns number of pages pinned upon success.
* If the pin request partially succeeds, or fails completely,
* all pages are left unpinned and a negative error value is returned.
*/
static int pfn_array_pin(struct pfn_array *pa, struct device *mdev)
{
int ret = 0;
ret = vfio_pin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr,
IOMMU_READ | IOMMU_WRITE, pa->pa_pfn);
if (ret < 0) {
goto err_out;
} else if (ret > 0 && ret != pa->pa_nr) {
vfio_unpin_pages(mdev, pa->pa_iova_pfn, ret);
ret = -EINVAL;
goto err_out;
}
return ret;
err_out:
pa->pa_nr = 0;
return ret;
}
/* Unpin the pages before releasing the memory. */
static void pfn_array_unpin_free(struct pfn_array *pa, struct device *mdev)
{
/* Only unpin if any pages were pinned to begin with */
if (pa->pa_nr)
vfio_unpin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr);
pa->pa_nr = 0;
kfree(pa->pa_iova_pfn);
}
static bool pfn_array_iova_pinned(struct pfn_array *pa, unsigned long iova)
{
unsigned long iova_pfn = iova >> PAGE_SHIFT;
int i;
for (i = 0; i < pa->pa_nr; i++)
if (pa->pa_iova_pfn[i] == iova_pfn)
return true;
return false;
}
/* Create the list of IDAL words for a pfn_array. */
static inline void pfn_array_idal_create_words(
struct pfn_array *pa,
unsigned long *idaws)
{
int i;
/*
* Idal words (execept the first one) rely on the memory being 4k
* aligned. If a user virtual address is 4K aligned, then it's
* corresponding kernel physical address will also be 4K aligned. Thus
* there will be no problem here to simply use the phys to create an
* idaw.
*/
for (i = 0; i < pa->pa_nr; i++)
idaws[i] = pa->pa_pfn[i] << PAGE_SHIFT;
/* Adjust the first IDAW, since it may not start on a page boundary */
idaws[0] += pa->pa_iova & (PAGE_SIZE - 1);
}
void convert_ccw0_to_ccw1(struct ccw1 *source, unsigned long len)
{
struct ccw0 ccw0;
struct ccw1 *pccw1 = source;
int i;
for (i = 0; i < len; i++) {
ccw0 = *(struct ccw0 *)pccw1;
if ((pccw1->cmd_code & 0x0f) == CCW_CMD_TIC) {
pccw1->cmd_code = CCW_CMD_TIC;
pccw1->flags = 0;
pccw1->count = 0;
} else {
pccw1->cmd_code = ccw0.cmd_code;
pccw1->flags = ccw0.flags;
pccw1->count = ccw0.count;
}
pccw1->cda = ccw0.cda;
pccw1++;
}
}
/*
* Within the domain (@mdev), copy @n bytes from a guest physical
* address (@iova) to a host physical address (@to).
*/
static long copy_from_iova(struct device *mdev,
void *to, u64 iova,
unsigned long n)
{
struct pfn_array pa = {0};
u64 from;
int i, ret;
unsigned long l, m;
ret = pfn_array_alloc(&pa, iova, n);
if (ret < 0)
return ret;
ret = pfn_array_pin(&pa, mdev);
if (ret < 0) {
pfn_array_unpin_free(&pa, mdev);
return ret;
}
l = n;
for (i = 0; i < pa.pa_nr; i++) {
from = pa.pa_pfn[i] << PAGE_SHIFT;
m = PAGE_SIZE;
if (i == 0) {
from += iova & (PAGE_SIZE - 1);
m -= iova & (PAGE_SIZE - 1);
}
m = min(l, m);
memcpy(to + (n - l), (void *)from, m);
l -= m;
if (l == 0)
break;
}
pfn_array_unpin_free(&pa, mdev);
return l;
}
/*
* Helpers to operate ccwchain.
*/
#define ccw_is_read(_ccw) (((_ccw)->cmd_code & 0x03) == 0x02)
#define ccw_is_read_backward(_ccw) (((_ccw)->cmd_code & 0x0F) == 0x0C)
#define ccw_is_sense(_ccw) (((_ccw)->cmd_code & 0x0F) == CCW_CMD_BASIC_SENSE)
#define ccw_is_noop(_ccw) ((_ccw)->cmd_code == CCW_CMD_NOOP)
#define ccw_is_tic(_ccw) ((_ccw)->cmd_code == CCW_CMD_TIC)
#define ccw_is_idal(_ccw) ((_ccw)->flags & CCW_FLAG_IDA)
#define ccw_is_skip(_ccw) ((_ccw)->flags & CCW_FLAG_SKIP)
#define ccw_is_chain(_ccw) ((_ccw)->flags & (CCW_FLAG_CC | CCW_FLAG_DC))
/*
* ccw_does_data_transfer()
*
* Determine whether a CCW will move any data, such that the guest pages
* would need to be pinned before performing the I/O.
*
* Returns 1 if yes, 0 if no.
*/
static inline int ccw_does_data_transfer(struct ccw1 *ccw)
{
/* If the count field is zero, then no data will be transferred */
if (ccw->count == 0)
return 0;
/* If the command is a NOP, then no data will be transferred */
if (ccw_is_noop(ccw))
return 0;
/* If the skip flag is off, then data will be transferred */
if (!ccw_is_skip(ccw))
return 1;
/*
* If the skip flag is on, it is only meaningful if the command
* code is a read, read backward, sense, or sense ID. In those
* cases, no data will be transferred.
*/
if (ccw_is_read(ccw) || ccw_is_read_backward(ccw))
return 0;
if (ccw_is_sense(ccw))
return 0;
/* The skip flag is on, but it is ignored for this command code. */
return 1;
}
/*
* is_cpa_within_range()
*
* @cpa: channel program address being questioned
* @head: address of the beginning of a CCW chain
* @len: number of CCWs within the chain
*
* Determine whether the address of a CCW (whether a new chain,
* or the target of a TIC) falls within a range (including the end points).
*
* Returns 1 if yes, 0 if no.
*/
static inline int is_cpa_within_range(u32 cpa, u32 head, int len)
{
u32 tail = head + (len - 1) * sizeof(struct ccw1);
return (head <= cpa && cpa <= tail);
}
static inline int is_tic_within_range(struct ccw1 *ccw, u32 head, int len)
{
if (!ccw_is_tic(ccw))
return 0;
return is_cpa_within_range(ccw->cda, head, len);
}
static struct ccwchain *ccwchain_alloc(struct channel_program *cp, int len)
{
struct ccwchain *chain;
void *data;
size_t size;
/* Make ccw address aligned to 8. */
size = ((sizeof(*chain) + 7L) & -8L) +
sizeof(*chain->ch_ccw) * len +
sizeof(*chain->ch_pa) * len;
chain = kzalloc(size, GFP_DMA | GFP_KERNEL);
if (!chain)
return NULL;
data = (u8 *)chain + ((sizeof(*chain) + 7L) & -8L);
chain->ch_ccw = (struct ccw1 *)data;
data = (u8 *)(chain->ch_ccw) + sizeof(*chain->ch_ccw) * len;
chain->ch_pa = (struct pfn_array *)data;
chain->ch_len = len;
list_add_tail(&chain->next, &cp->ccwchain_list);
return chain;
}
static void ccwchain_free(struct ccwchain *chain)
{
list_del(&chain->next);
kfree(chain);
}
/* Free resource for a ccw that allocated memory for its cda. */
static void ccwchain_cda_free(struct ccwchain *chain, int idx)
{
struct ccw1 *ccw = chain->ch_ccw + idx;
if (ccw_is_tic(ccw))
return;
kfree((void *)(u64)ccw->cda);
}
/**
* ccwchain_calc_length - calculate the length of the ccw chain.
* @iova: guest physical address of the target ccw chain
* @cp: channel_program on which to perform the operation
*
* This is the chain length not considering any TICs.
* You need to do a new round for each TIC target.
*
* The program is also validated for absence of not yet supported
* indirect data addressing scenarios.
*
* Returns: the length of the ccw chain or -errno.
*/
static int ccwchain_calc_length(u64 iova, struct channel_program *cp)
{
struct ccw1 *ccw = cp->guest_cp;
int cnt = 0;
do {
cnt++;
/*
* As we don't want to fail direct addressing even if the
* orb specified one of the unsupported formats, we defer
* checking for IDAWs in unsupported formats to here.
*/
if ((!cp->orb.cmd.c64 || cp->orb.cmd.i2k) && ccw_is_idal(ccw))
return -EOPNOTSUPP;
/*
* We want to keep counting if the current CCW has the
* command-chaining flag enabled, or if it is a TIC CCW
* that loops back into the current chain. The latter
* is used for device orientation, where the CCW PRIOR to
* the TIC can either jump to the TIC or a CCW immediately
* after the TIC, depending on the results of its operation.
*/
if (!ccw_is_chain(ccw) && !is_tic_within_range(ccw, iova, cnt))
break;
ccw++;
} while (cnt < CCWCHAIN_LEN_MAX + 1);
if (cnt == CCWCHAIN_LEN_MAX + 1)
cnt = -EINVAL;
return cnt;
}
static int tic_target_chain_exists(struct ccw1 *tic, struct channel_program *cp)
{
struct ccwchain *chain;
u32 ccw_head;
list_for_each_entry(chain, &cp->ccwchain_list, next) {
ccw_head = chain->ch_iova;
if (is_cpa_within_range(tic->cda, ccw_head, chain->ch_len))
return 1;
}
return 0;
}
static int ccwchain_loop_tic(struct ccwchain *chain,
struct channel_program *cp);
static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp)
{
struct ccwchain *chain;
int len;
/* Copy 2K (the most we support today) of possible CCWs */
len = copy_from_iova(cp->mdev, cp->guest_cp, cda,
CCWCHAIN_LEN_MAX * sizeof(struct ccw1));
if (len)
return len;
/* Convert any Format-0 CCWs to Format-1 */
if (!cp->orb.cmd.fmt)
convert_ccw0_to_ccw1(cp->guest_cp, len);
/* Count the CCWs in the current chain */
len = ccwchain_calc_length(cda, cp);
if (len < 0)
return len;
/* Need alloc a new chain for this one. */
chain = ccwchain_alloc(cp, len);
if (!chain)
return -ENOMEM;
chain->ch_iova = cda;
/* Copy the actual CCWs into the new chain */
memcpy(chain->ch_ccw, cp->guest_cp, len * sizeof(struct ccw1));
/* Loop for tics on this new chain. */
return ccwchain_loop_tic(chain, cp);
}
/* Loop for TICs. */
static int ccwchain_loop_tic(struct ccwchain *chain, struct channel_program *cp)
{
struct ccw1 *tic;
int i, ret;
for (i = 0; i < chain->ch_len; i++) {
tic = chain->ch_ccw + i;
if (!ccw_is_tic(tic))
continue;
/* May transfer to an existing chain. */
if (tic_target_chain_exists(tic, cp))
continue;
/* Build a ccwchain for the next segment */
ret = ccwchain_handle_ccw(tic->cda, cp);
if (ret)
return ret;
}
return 0;
}
static int ccwchain_fetch_tic(struct ccwchain *chain,
int idx,
struct channel_program *cp)
{
struct ccw1 *ccw = chain->ch_ccw + idx;
struct ccwchain *iter;
u32 ccw_head;
list_for_each_entry(iter, &cp->ccwchain_list, next) {
ccw_head = iter->ch_iova;
if (is_cpa_within_range(ccw->cda, ccw_head, iter->ch_len)) {
ccw->cda = (__u32) (addr_t) (((char *)iter->ch_ccw) +
(ccw->cda - ccw_head));
return 0;
}
}
return -EFAULT;
}
static int ccwchain_fetch_direct(struct ccwchain *chain,
int idx,
struct channel_program *cp)
{
struct ccw1 *ccw;
struct pfn_array *pa;
u64 iova;
unsigned long *idaws;
int ret;
int bytes = 1;
int idaw_nr, idal_len;
int i;
ccw = chain->ch_ccw + idx;
if (ccw->count)
bytes = ccw->count;
/* Calculate size of IDAL */
if (ccw_is_idal(ccw)) {
/* Read first IDAW to see if it's 4K-aligned or not. */
/* All subsequent IDAws will be 4K-aligned. */
ret = copy_from_iova(cp->mdev, &iova, ccw->cda, sizeof(iova));
if (ret)
return ret;
} else {
iova = ccw->cda;
}
idaw_nr = idal_nr_words((void *)iova, bytes);
idal_len = idaw_nr * sizeof(*idaws);
/* Allocate an IDAL from host storage */
idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
if (!idaws) {
ret = -ENOMEM;
goto out_init;
}
/*
* Allocate an array of pfn's for pages to pin/translate.
* The number of pages is actually the count of the idaws
* required for the data transfer, since we only only support
* 4K IDAWs today.
*/
pa = chain->ch_pa + idx;
ret = pfn_array_alloc(pa, iova, bytes);
if (ret < 0)
goto out_free_idaws;
if (ccw_is_idal(ccw)) {
/* Copy guest IDAL into host IDAL */
ret = copy_from_iova(cp->mdev, idaws, ccw->cda, idal_len);
if (ret)
goto out_unpin;
/*
* Copy guest IDAWs into pfn_array, in case the memory they
* occupy is not contiguous.
*/
for (i = 0; i < idaw_nr; i++)
pa->pa_iova_pfn[i] = idaws[i] >> PAGE_SHIFT;
} else {
/*
* No action is required here; the iova addresses in pfn_array
* were initialized sequentially in pfn_array_alloc() beginning
* with the contents of ccw->cda.
*/
}
if (ccw_does_data_transfer(ccw)) {
ret = pfn_array_pin(pa, cp->mdev);
if (ret < 0)
goto out_unpin;
} else {
pa->pa_nr = 0;
}
ccw->cda = (__u32) virt_to_phys(idaws);
ccw->flags |= CCW_FLAG_IDA;
/* Populate the IDAL with pinned/translated addresses from pfn */
pfn_array_idal_create_words(pa, idaws);
return 0;
out_unpin:
pfn_array_unpin_free(pa, cp->mdev);
out_free_idaws:
kfree(idaws);
out_init:
ccw->cda = 0;
return ret;
}
/*
* Fetch one ccw.
* To reduce memory copy, we'll pin the cda page in memory,
* and to get rid of the cda 2G limitiaion of ccw1, we'll translate
* direct ccws to idal ccws.
*/
static int ccwchain_fetch_one(struct ccwchain *chain,
int idx,
struct channel_program *cp)
{
struct ccw1 *ccw = chain->ch_ccw + idx;
if (ccw_is_tic(ccw))
return ccwchain_fetch_tic(chain, idx, cp);
return ccwchain_fetch_direct(chain, idx, cp);
}
/**
* cp_init() - allocate ccwchains for a channel program.
* @cp: channel_program on which to perform the operation
* @mdev: the mediated device to perform pin/unpin operations
* @orb: control block for the channel program from the guest
*
* This creates one or more ccwchain(s), and copies the raw data of
* the target channel program from @orb->cmd.iova to the new ccwchain(s).
*
* Limitations:
* 1. Supports only prefetch enabled mode.
* 2. Supports idal(c64) ccw chaining.
* 3. Supports 4k idaw.
*
* Returns:
* %0 on success and a negative error value on failure.
*/
int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb)
{
int ret;
/*
* XXX:
* Only support prefetch enable mode now.
*/
if (!orb->cmd.pfch)
return -EOPNOTSUPP;
INIT_LIST_HEAD(&cp->ccwchain_list);
memcpy(&cp->orb, orb, sizeof(*orb));
cp->mdev = mdev;
/* Build a ccwchain for the first CCW segment */
ret = ccwchain_handle_ccw(orb->cmd.cpa, cp);
if (ret)
cp_free(cp);
/* It is safe to force: if not set but idals used
* ccwchain_calc_length returns an error.
*/
cp->orb.cmd.c64 = 1;
if (!ret)
cp->initialized = true;
return ret;
}
/**
* cp_free() - free resources for channel program.
* @cp: channel_program on which to perform the operation
*
* This unpins the memory pages and frees the memory space occupied by
* @cp, which must have been returned by a previous call to cp_init().
* Otherwise, undefined behavior occurs.
*/
void cp_free(struct channel_program *cp)
{
struct ccwchain *chain, *temp;
int i;
if (!cp->initialized)
return;
cp->initialized = false;
list_for_each_entry_safe(chain, temp, &cp->ccwchain_list, next) {
for (i = 0; i < chain->ch_len; i++) {
pfn_array_unpin_free(chain->ch_pa + i, cp->mdev);
ccwchain_cda_free(chain, i);
}
ccwchain_free(chain);
}
}
/**
* cp_prefetch() - translate a guest physical address channel program to
* a real-device runnable channel program.
* @cp: channel_program on which to perform the operation
*
* This function translates the guest-physical-address channel program
* and stores the result to ccwchain list. @cp must have been
* initialized by a previous call with cp_init(). Otherwise, undefined
* behavior occurs.
* For each chain composing the channel program:
* - On entry ch_len holds the count of CCWs to be translated.
* - On exit ch_len is adjusted to the count of successfully translated CCWs.
* This allows cp_free to find in ch_len the count of CCWs to free in a chain.
*
* The S/390 CCW Translation APIS (prefixed by 'cp_') are introduced
* as helpers to do ccw chain translation inside the kernel. Basically
* they accept a channel program issued by a virtual machine, and
* translate the channel program to a real-device runnable channel
* program.
*
* These APIs will copy the ccws into kernel-space buffers, and update
* the guest phsical addresses with their corresponding host physical
* addresses. Then channel I/O device drivers could issue the
* translated channel program to real devices to perform an I/O
* operation.
*
* These interfaces are designed to support translation only for
* channel programs, which are generated and formatted by a
* guest. Thus this will make it possible for things like VFIO to
* leverage the interfaces to passthrough a channel I/O mediated
* device in QEMU.
*
* We support direct ccw chaining by translating them to idal ccws.
*
* Returns:
* %0 on success and a negative error value on failure.
*/
int cp_prefetch(struct channel_program *cp)
{
struct ccwchain *chain;
int len, idx, ret;
/* this is an error in the caller */
if (!cp->initialized)
return -EINVAL;
list_for_each_entry(chain, &cp->ccwchain_list, next) {
len = chain->ch_len;
for (idx = 0; idx < len; idx++) {
ret = ccwchain_fetch_one(chain, idx, cp);
if (ret)
goto out_err;
}
}
return 0;
out_err:
/* Only cleanup the chain elements that were actually translated. */
chain->ch_len = idx;
list_for_each_entry_continue(chain, &cp->ccwchain_list, next) {
chain->ch_len = 0;
}
return ret;
}
/**
* cp_get_orb() - get the orb of the channel program
* @cp: channel_program on which to perform the operation
* @intparm: new intparm for the returned orb
* @lpm: candidate value of the logical-path mask for the returned orb
*
* This function returns the address of the updated orb of the channel
* program. Channel I/O device drivers could use this orb to issue a
* ssch.
*/
union orb *cp_get_orb(struct channel_program *cp, u32 intparm, u8 lpm)
{
union orb *orb;
struct ccwchain *chain;
struct ccw1 *cpa;
/* this is an error in the caller */
if (!cp->initialized)
return NULL;
orb = &cp->orb;
orb->cmd.intparm = intparm;
orb->cmd.fmt = 1;
orb->cmd.key = PAGE_DEFAULT_KEY >> 4;
if (orb->cmd.lpm == 0)
orb->cmd.lpm = lpm;
chain = list_first_entry(&cp->ccwchain_list, struct ccwchain, next);
cpa = chain->ch_ccw;
orb->cmd.cpa = (__u32) __pa(cpa);
return orb;
}
/**
* cp_update_scsw() - update scsw for a channel program.
* @cp: channel_program on which to perform the operation
* @scsw: I/O results of the channel program and also the target to be
* updated
*
* @scsw contains the I/O results of the channel program that pointed
* to by @cp. However what @scsw->cpa stores is a host physical
* address, which is meaningless for the guest, which is waiting for
* the I/O results.
*
* This function updates @scsw->cpa to its coressponding guest physical
* address.
*/
void cp_update_scsw(struct channel_program *cp, union scsw *scsw)
{
struct ccwchain *chain;
u32 cpa = scsw->cmd.cpa;
u32 ccw_head;
if (!cp->initialized)
return;
/*
* LATER:
* For now, only update the cmd.cpa part. We may need to deal with
* other portions of the schib as well, even if we don't return them
* in the ioctl directly. Path status changes etc.
*/
list_for_each_entry(chain, &cp->ccwchain_list, next) {
ccw_head = (u32)(u64)chain->ch_ccw;
/*
* On successful execution, cpa points just beyond the end
* of the chain.
*/
if (is_cpa_within_range(cpa, ccw_head, chain->ch_len + 1)) {
/*
* (cpa - ccw_head) is the offset value of the host
* physical ccw to its chain head.
* Adding this value to the guest physical ccw chain
* head gets us the guest cpa.
*/
cpa = chain->ch_iova + (cpa - ccw_head);
break;
}
}
scsw->cmd.cpa = cpa;
}
/**
* cp_iova_pinned() - check if an iova is pinned for a ccw chain.
* @cp: channel_program on which to perform the operation
* @iova: the iova to check
*
* If the @iova is currently pinned for the ccw chain, return true;
* else return false.
*/
bool cp_iova_pinned(struct channel_program *cp, u64 iova)
{
struct ccwchain *chain;
int i;
if (!cp->initialized)
return false;
list_for_each_entry(chain, &cp->ccwchain_list, next) {
for (i = 0; i < chain->ch_len; i++)
if (pfn_array_iova_pinned(chain->ch_pa + i, iova))
return true;
}
return false;
}