1 // SPDX-License-Identifier: GPL-2.0
3 * channel program interfaces
5 * Copyright IBM Corp. 2017
7 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
8 * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
11 #include <linux/ratelimit.h>
13 #include <linux/slab.h>
14 #include <linux/highmem.h>
15 #include <linux/iommu.h>
16 #include <linux/vfio.h>
17 #include <asm/idals.h>
19 #include "vfio_ccw_cp.h"
20 #include "vfio_ccw_private.h"
23 /* Array that stores pages need to pin. */
25 /* Array that receives the pinned pages. */
26 struct page **pa_page;
27 /* Number of pages pinned from @pa_iova. */
32 struct list_head next;
34 /* Guest physical address of the current chain. */
36 /* Count of the valid ccws in chain. */
38 /* Pinned PAGEs for the original data. */
39 struct page_array *ch_pa;
43 * page_array_alloc() - alloc memory for page array
44 * @pa: page_array on which to perform the operation
45 * @len: number of pages that should be pinned from @iova
47 * Attempt to allocate memory for page array.
49 * Usage of page_array:
50 * We expect (pa_nr == 0) and (pa_iova == NULL), any field in
51 * this structure will be filled in by this function.
54 * 0 if page array is allocated
55 * -EINVAL if pa->pa_nr is not initially zero, or pa->pa_iova is not NULL
56 * -ENOMEM if alloc failed
58 static int page_array_alloc(struct page_array *pa, unsigned int len)
60 if (pa->pa_nr || pa->pa_iova)
68 pa->pa_iova = kcalloc(len, sizeof(*pa->pa_iova), GFP_KERNEL);
72 pa->pa_page = kcalloc(len, sizeof(*pa->pa_page), GFP_KERNEL);
82 * page_array_unpin() - Unpin user pages in memory
83 * @pa: page_array on which to perform the operation
84 * @vdev: the vfio device to perform the operation
85 * @pa_nr: number of user pages to unpin
86 * @unaligned: were pages unaligned on the pin request
88 * Only unpin if any pages were pinned to begin with, i.e. pa_nr > 0,
89 * otherwise only clear pa->pa_nr
91 static void page_array_unpin(struct page_array *pa,
92 struct vfio_device *vdev, int pa_nr, bool unaligned)
94 int unpinned = 0, npage = 1;
96 while (unpinned < pa_nr) {
97 dma_addr_t *first = &pa->pa_iova[unpinned];
98 dma_addr_t *last = &first[npage];
100 if (unpinned + npage < pa_nr &&
101 *first + npage * PAGE_SIZE == *last &&
107 vfio_unpin_pages(vdev, *first, npage);
116 * page_array_pin() - Pin user pages in memory
117 * @pa: page_array on which to perform the operation
118 * @vdev: the vfio device to perform pin operations
119 * @unaligned: are pages aligned to 4K boundary?
121 * Returns number of pages pinned upon success.
122 * If the pin request partially succeeds, or fails completely,
123 * all pages are left unpinned and a negative error value is returned.
125 * Requests to pin "aligned" pages can be coalesced into a single
126 * vfio_pin_pages request for the sake of efficiency, based on the
127 * expectation of 4K page requests. Unaligned requests are probably
128 * dealing with 2K "pages", and cannot be coalesced without
129 * reworking this logic to incorporate that math.
131 static int page_array_pin(struct page_array *pa, struct vfio_device *vdev, bool unaligned)
133 int pinned = 0, npage = 1;
136 while (pinned < pa->pa_nr) {
137 dma_addr_t *first = &pa->pa_iova[pinned];
138 dma_addr_t *last = &first[npage];
140 if (pinned + npage < pa->pa_nr &&
141 *first + npage * PAGE_SIZE == *last &&
147 ret = vfio_pin_pages(vdev, *first, npage,
148 IOMMU_READ | IOMMU_WRITE,
149 &pa->pa_page[pinned]);
152 } else if (ret > 0 && ret != npage) {
164 page_array_unpin(pa, vdev, pinned, unaligned);
168 /* Unpin the pages before releasing the memory. */
169 static void page_array_unpin_free(struct page_array *pa, struct vfio_device *vdev, bool unaligned)
171 page_array_unpin(pa, vdev, pa->pa_nr, unaligned);
176 static bool page_array_iova_pinned(struct page_array *pa, u64 iova, u64 length)
178 u64 iova_pfn_start = iova >> PAGE_SHIFT;
179 u64 iova_pfn_end = (iova + length - 1) >> PAGE_SHIFT;
183 for (i = 0; i < pa->pa_nr; i++) {
184 pfn = pa->pa_iova[i] >> PAGE_SHIFT;
185 if (pfn >= iova_pfn_start && pfn <= iova_pfn_end)
191 /* Create the list of IDAL words for a page_array. */
192 static inline void page_array_idal_create_words(struct page_array *pa,
198 * Idal words (execept the first one) rely on the memory being 4k
199 * aligned. If a user virtual address is 4K aligned, then it's
200 * corresponding kernel physical address will also be 4K aligned. Thus
201 * there will be no problem here to simply use the phys to create an
205 for (i = 0; i < pa->pa_nr; i++) {
206 idaws[i] = virt_to_dma64(page_to_virt(pa->pa_page[i]));
208 /* Incorporate any offset from each starting address */
209 idaws[i] = dma64_add(idaws[i], pa->pa_iova[i] & ~PAGE_MASK);
213 static void convert_ccw0_to_ccw1(struct ccw1 *source, unsigned long len)
216 struct ccw1 *pccw1 = source;
219 for (i = 0; i < len; i++) {
220 ccw0 = *(struct ccw0 *)pccw1;
221 if ((pccw1->cmd_code & 0x0f) == CCW_CMD_TIC) {
222 pccw1->cmd_code = CCW_CMD_TIC;
226 pccw1->cmd_code = ccw0.cmd_code;
227 pccw1->flags = ccw0.flags;
228 pccw1->count = ccw0.count;
230 pccw1->cda = u32_to_dma32(ccw0.cda);
235 #define idal_is_2k(_cp) (!(_cp)->orb.cmd.c64 || (_cp)->orb.cmd.i2k)
238 * Helpers to operate ccwchain.
240 #define ccw_is_read(_ccw) (((_ccw)->cmd_code & 0x03) == 0x02)
241 #define ccw_is_read_backward(_ccw) (((_ccw)->cmd_code & 0x0F) == 0x0C)
242 #define ccw_is_sense(_ccw) (((_ccw)->cmd_code & 0x0F) == CCW_CMD_BASIC_SENSE)
244 #define ccw_is_noop(_ccw) ((_ccw)->cmd_code == CCW_CMD_NOOP)
246 #define ccw_is_tic(_ccw) ((_ccw)->cmd_code == CCW_CMD_TIC)
248 #define ccw_is_idal(_ccw) ((_ccw)->flags & CCW_FLAG_IDA)
249 #define ccw_is_skip(_ccw) ((_ccw)->flags & CCW_FLAG_SKIP)
251 #define ccw_is_chain(_ccw) ((_ccw)->flags & (CCW_FLAG_CC | CCW_FLAG_DC))
254 * ccw_does_data_transfer()
256 * Determine whether a CCW will move any data, such that the guest pages
257 * would need to be pinned before performing the I/O.
259 * Returns 1 if yes, 0 if no.
261 static inline int ccw_does_data_transfer(struct ccw1 *ccw)
263 /* If the count field is zero, then no data will be transferred */
267 /* If the command is a NOP, then no data will be transferred */
268 if (ccw_is_noop(ccw))
271 /* If the skip flag is off, then data will be transferred */
272 if (!ccw_is_skip(ccw))
276 * If the skip flag is on, it is only meaningful if the command
277 * code is a read, read backward, sense, or sense ID. In those
278 * cases, no data will be transferred.
280 if (ccw_is_read(ccw) || ccw_is_read_backward(ccw))
283 if (ccw_is_sense(ccw))
286 /* The skip flag is on, but it is ignored for this command code. */
291 * is_cpa_within_range()
293 * @cpa: channel program address being questioned
294 * @head: address of the beginning of a CCW chain
295 * @len: number of CCWs within the chain
297 * Determine whether the address of a CCW (whether a new chain,
298 * or the target of a TIC) falls within a range (including the end points).
300 * Returns 1 if yes, 0 if no.
302 static inline int is_cpa_within_range(dma32_t cpa, u32 head, int len)
304 u32 tail = head + (len - 1) * sizeof(struct ccw1);
305 u32 gcpa = dma32_to_u32(cpa);
307 return head <= gcpa && gcpa <= tail;
310 static inline int is_tic_within_range(struct ccw1 *ccw, u32 head, int len)
312 if (!ccw_is_tic(ccw))
315 return is_cpa_within_range(ccw->cda, head, len);
318 static struct ccwchain *ccwchain_alloc(struct channel_program *cp, int len)
320 struct ccwchain *chain;
322 chain = kzalloc(sizeof(*chain), GFP_KERNEL);
326 chain->ch_ccw = kcalloc(len, sizeof(*chain->ch_ccw), GFP_DMA | GFP_KERNEL);
330 chain->ch_pa = kcalloc(len, sizeof(*chain->ch_pa), GFP_KERNEL);
334 list_add_tail(&chain->next, &cp->ccwchain_list);
339 kfree(chain->ch_ccw);
344 static void ccwchain_free(struct ccwchain *chain)
346 list_del(&chain->next);
348 kfree(chain->ch_ccw);
352 /* Free resource for a ccw that allocated memory for its cda. */
353 static void ccwchain_cda_free(struct ccwchain *chain, int idx)
355 struct ccw1 *ccw = &chain->ch_ccw[idx];
360 kfree(dma32_to_virt(ccw->cda));
364 * ccwchain_calc_length - calculate the length of the ccw chain.
365 * @iova: guest physical address of the target ccw chain
366 * @cp: channel_program on which to perform the operation
368 * This is the chain length not considering any TICs.
369 * You need to do a new round for each TIC target.
371 * The program is also validated for absence of not yet supported
372 * indirect data addressing scenarios.
374 * Returns: the length of the ccw chain or -errno.
376 static int ccwchain_calc_length(u64 iova, struct channel_program *cp)
378 struct ccw1 *ccw = cp->guest_cp;
385 * We want to keep counting if the current CCW has the
386 * command-chaining flag enabled, or if it is a TIC CCW
387 * that loops back into the current chain. The latter
388 * is used for device orientation, where the CCW PRIOR to
389 * the TIC can either jump to the TIC or a CCW immediately
390 * after the TIC, depending on the results of its operation.
392 if (!ccw_is_chain(ccw) && !is_tic_within_range(ccw, iova, cnt))
396 } while (cnt < CCWCHAIN_LEN_MAX + 1);
398 if (cnt == CCWCHAIN_LEN_MAX + 1)
404 static int tic_target_chain_exists(struct ccw1 *tic, struct channel_program *cp)
406 struct ccwchain *chain;
409 list_for_each_entry(chain, &cp->ccwchain_list, next) {
410 ccw_head = chain->ch_iova;
411 if (is_cpa_within_range(tic->cda, ccw_head, chain->ch_len))
418 static int ccwchain_loop_tic(struct ccwchain *chain,
419 struct channel_program *cp);
421 static int ccwchain_handle_ccw(dma32_t cda, struct channel_program *cp)
423 struct vfio_device *vdev =
424 &container_of(cp, struct vfio_ccw_private, cp)->vdev;
425 struct ccwchain *chain;
429 gcda = dma32_to_u32(cda);
430 /* Copy 2K (the most we support today) of possible CCWs */
431 ret = vfio_dma_rw(vdev, gcda, cp->guest_cp, CCWCHAIN_LEN_MAX * sizeof(struct ccw1), false);
435 /* Convert any Format-0 CCWs to Format-1 */
436 if (!cp->orb.cmd.fmt)
437 convert_ccw0_to_ccw1(cp->guest_cp, CCWCHAIN_LEN_MAX);
439 /* Count the CCWs in the current chain */
440 len = ccwchain_calc_length(gcda, cp);
444 /* Need alloc a new chain for this one. */
445 chain = ccwchain_alloc(cp, len);
450 chain->ch_iova = gcda;
452 /* Copy the actual CCWs into the new chain */
453 memcpy(chain->ch_ccw, cp->guest_cp, len * sizeof(struct ccw1));
455 /* Loop for tics on this new chain. */
456 ret = ccwchain_loop_tic(chain, cp);
459 ccwchain_free(chain);
465 static int ccwchain_loop_tic(struct ccwchain *chain, struct channel_program *cp)
470 for (i = 0; i < chain->ch_len; i++) {
471 tic = &chain->ch_ccw[i];
473 if (!ccw_is_tic(tic))
476 /* May transfer to an existing chain. */
477 if (tic_target_chain_exists(tic, cp))
480 /* Build a ccwchain for the next segment */
481 ret = ccwchain_handle_ccw(tic->cda, cp);
489 static int ccwchain_fetch_tic(struct ccw1 *ccw,
490 struct channel_program *cp)
492 struct ccwchain *iter;
495 list_for_each_entry(iter, &cp->ccwchain_list, next) {
496 ccw_head = iter->ch_iova;
497 if (is_cpa_within_range(ccw->cda, ccw_head, iter->ch_len)) {
498 cda = (u64)iter->ch_ccw + dma32_to_u32(ccw->cda) - ccw_head;
499 ccw->cda = u32_to_dma32(cda);
507 static dma64_t *get_guest_idal(struct ccw1 *ccw, struct channel_program *cp, int idaw_nr)
509 struct vfio_device *vdev =
510 &container_of(cp, struct vfio_ccw_private, cp)->vdev;
513 int idal_len = idaw_nr * sizeof(*idaws);
514 int idaw_size = idal_is_2k(cp) ? PAGE_SIZE / 2 : PAGE_SIZE;
515 int idaw_mask = ~(idaw_size - 1);
518 idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
520 return ERR_PTR(-ENOMEM);
522 if (ccw_is_idal(ccw)) {
523 /* Copy IDAL from guest */
524 ret = vfio_dma_rw(vdev, dma32_to_u32(ccw->cda), idaws, idal_len, false);
530 /* Fabricate an IDAL based off CCW data address */
531 if (cp->orb.cmd.c64) {
532 idaws[0] = u64_to_dma64(dma32_to_u32(ccw->cda));
533 for (i = 1; i < idaw_nr; i++) {
534 idaws[i] = dma64_add(idaws[i - 1], idaw_size);
535 idaws[i] = dma64_and(idaws[i], idaw_mask);
538 idaws_f1 = (dma32_t *)idaws;
539 idaws_f1[0] = ccw->cda;
540 for (i = 1; i < idaw_nr; i++) {
541 idaws_f1[i] = dma32_add(idaws_f1[i - 1], idaw_size);
542 idaws_f1[i] = dma32_and(idaws_f1[i], idaw_mask);
551 * ccw_count_idaws() - Calculate the number of IDAWs needed to transfer
552 * a specified amount of data
554 * @ccw: The Channel Command Word being translated
555 * @cp: Channel Program being processed
557 * The ORB is examined, since it specifies what IDAWs could actually be
558 * used by any CCW in the channel program, regardless of whether or not
559 * the CCW actually does. An ORB that does not specify Format-2-IDAW
560 * Control could still contain a CCW with an IDAL, which would be
561 * Format-1 and thus only move 2K with each IDAW. Thus all CCWs within
562 * the channel program must follow the same size requirements.
564 static int ccw_count_idaws(struct ccw1 *ccw,
565 struct channel_program *cp)
567 struct vfio_device *vdev =
568 &container_of(cp, struct vfio_ccw_private, cp)->vdev;
570 int size = cp->orb.cmd.c64 ? sizeof(u64) : sizeof(u32);
577 if (ccw_is_idal(ccw)) {
578 /* Read first IDAW to check its starting address. */
579 /* All subsequent IDAWs will be 2K- or 4K-aligned. */
580 ret = vfio_dma_rw(vdev, dma32_to_u32(ccw->cda), &iova, size, false);
585 * Format-1 IDAWs only occupy the first 32 bits,
586 * and bit 0 is always off.
588 if (!cp->orb.cmd.c64)
591 iova = dma32_to_u32(ccw->cda);
594 /* Format-1 IDAWs operate on 2K each */
595 if (!cp->orb.cmd.c64)
596 return idal_2k_nr_words((void *)iova, bytes);
598 /* Using the 2K variant of Format-2 IDAWs? */
600 return idal_2k_nr_words((void *)iova, bytes);
602 /* The 'usual' case is 4K Format-2 IDAWs */
603 return idal_nr_words((void *)iova, bytes);
606 static int ccwchain_fetch_ccw(struct ccw1 *ccw,
607 struct page_array *pa,
608 struct channel_program *cp)
610 struct vfio_device *vdev =
611 &container_of(cp, struct vfio_ccw_private, cp)->vdev;
618 /* Calculate size of IDAL */
619 idaw_nr = ccw_count_idaws(ccw, cp);
623 /* Allocate an IDAL from host storage */
624 idaws = get_guest_idal(ccw, cp, idaw_nr);
626 ret = PTR_ERR(idaws);
631 * Allocate an array of pages to pin/translate.
632 * The number of pages is actually the count of the idaws
633 * required for the data transfer, since we only only support
636 ret = page_array_alloc(pa, idaw_nr);
641 * Copy guest IDAWs into page_array, in case the memory they
642 * occupy is not contiguous.
644 idaws_f1 = (dma32_t *)idaws;
645 for (i = 0; i < idaw_nr; i++) {
647 pa->pa_iova[i] = dma64_to_u64(idaws[i]);
649 pa->pa_iova[i] = dma32_to_u32(idaws_f1[i]);
652 if (ccw_does_data_transfer(ccw)) {
653 ret = page_array_pin(pa, vdev, idal_is_2k(cp));
660 ccw->cda = virt_to_dma32(idaws);
661 ccw->flags |= CCW_FLAG_IDA;
663 /* Populate the IDAL with pinned/translated addresses from page */
664 page_array_idal_create_words(pa, idaws);
669 page_array_unpin_free(pa, vdev, idal_is_2k(cp));
679 * To reduce memory copy, we'll pin the cda page in memory,
680 * and to get rid of the cda 2G limitation of ccw1, we'll translate
681 * direct ccws to idal ccws.
683 static int ccwchain_fetch_one(struct ccw1 *ccw,
684 struct page_array *pa,
685 struct channel_program *cp)
689 return ccwchain_fetch_tic(ccw, cp);
691 return ccwchain_fetch_ccw(ccw, pa, cp);
695 * cp_init() - allocate ccwchains for a channel program.
696 * @cp: channel_program on which to perform the operation
697 * @orb: control block for the channel program from the guest
699 * This creates one or more ccwchain(s), and copies the raw data of
700 * the target channel program from @orb->cmd.iova to the new ccwchain(s).
703 * 1. Supports idal(c64) ccw chaining.
704 * 2. Supports 4k idaw.
707 * %0 on success and a negative error value on failure.
709 int cp_init(struct channel_program *cp, union orb *orb)
711 struct vfio_device *vdev =
712 &container_of(cp, struct vfio_ccw_private, cp)->vdev;
713 /* custom ratelimit used to avoid flood during guest IPL */
714 static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 1);
717 /* this is an error in the caller */
722 * We only support prefetching the channel program. We assume all channel
723 * programs executed by supported guests likewise support prefetching.
724 * Executing a channel program that does not specify prefetching will
725 * typically not cause an error, but a warning is issued to help identify
726 * the problem if something does break.
728 if (!orb->cmd.pfch && __ratelimit(&ratelimit_state))
731 "Prefetching channel program even though prefetch not specified in ORB");
733 INIT_LIST_HEAD(&cp->ccwchain_list);
734 memcpy(&cp->orb, orb, sizeof(*orb));
736 /* Build a ccwchain for the first CCW segment */
737 ret = ccwchain_handle_ccw(orb->cmd.cpa, cp);
740 cp->initialized = true;
747 * cp_free() - free resources for channel program.
748 * @cp: channel_program on which to perform the operation
750 * This unpins the memory pages and frees the memory space occupied by
751 * @cp, which must have been returned by a previous call to cp_init().
752 * Otherwise, undefined behavior occurs.
754 void cp_free(struct channel_program *cp)
756 struct vfio_device *vdev =
757 &container_of(cp, struct vfio_ccw_private, cp)->vdev;
758 struct ccwchain *chain, *temp;
761 if (!cp->initialized)
764 cp->initialized = false;
765 list_for_each_entry_safe(chain, temp, &cp->ccwchain_list, next) {
766 for (i = 0; i < chain->ch_len; i++) {
767 page_array_unpin_free(&chain->ch_pa[i], vdev, idal_is_2k(cp));
768 ccwchain_cda_free(chain, i);
770 ccwchain_free(chain);
775 * cp_prefetch() - translate a guest physical address channel program to
776 * a real-device runnable channel program.
777 * @cp: channel_program on which to perform the operation
779 * This function translates the guest-physical-address channel program
780 * and stores the result to ccwchain list. @cp must have been
781 * initialized by a previous call with cp_init(). Otherwise, undefined
783 * For each chain composing the channel program:
784 * - On entry ch_len holds the count of CCWs to be translated.
785 * - On exit ch_len is adjusted to the count of successfully translated CCWs.
786 * This allows cp_free to find in ch_len the count of CCWs to free in a chain.
788 * The S/390 CCW Translation APIS (prefixed by 'cp_') are introduced
789 * as helpers to do ccw chain translation inside the kernel. Basically
790 * they accept a channel program issued by a virtual machine, and
791 * translate the channel program to a real-device runnable channel
794 * These APIs will copy the ccws into kernel-space buffers, and update
795 * the guest physical addresses with their corresponding host physical
796 * addresses. Then channel I/O device drivers could issue the
797 * translated channel program to real devices to perform an I/O
800 * These interfaces are designed to support translation only for
801 * channel programs, which are generated and formatted by a
802 * guest. Thus this will make it possible for things like VFIO to
803 * leverage the interfaces to passthrough a channel I/O mediated
806 * We support direct ccw chaining by translating them to idal ccws.
809 * %0 on success and a negative error value on failure.
811 int cp_prefetch(struct channel_program *cp)
813 struct ccwchain *chain;
815 struct page_array *pa;
818 /* this is an error in the caller */
819 if (!cp->initialized)
822 list_for_each_entry(chain, &cp->ccwchain_list, next) {
824 for (idx = 0; idx < len; idx++) {
825 ccw = &chain->ch_ccw[idx];
826 pa = &chain->ch_pa[idx];
828 ret = ccwchain_fetch_one(ccw, pa, cp);
836 /* Only cleanup the chain elements that were actually translated. */
838 list_for_each_entry_continue(chain, &cp->ccwchain_list, next) {
845 * cp_get_orb() - get the orb of the channel program
846 * @cp: channel_program on which to perform the operation
847 * @sch: subchannel the operation will be performed against
849 * This function returns the address of the updated orb of the channel
850 * program. Channel I/O device drivers could use this orb to issue a
853 union orb *cp_get_orb(struct channel_program *cp, struct subchannel *sch)
856 struct ccwchain *chain;
859 /* this is an error in the caller */
860 if (!cp->initialized)
865 orb->cmd.intparm = (u32)virt_to_phys(sch);
869 * Everything built by vfio-ccw is a Format-2 IDAL.
870 * If the input was a Format-1 IDAL, indicate that
871 * 2K Format-2 IDAWs were created here.
877 if (orb->cmd.lpm == 0)
878 orb->cmd.lpm = sch->lpm;
880 chain = list_first_entry(&cp->ccwchain_list, struct ccwchain, next);
882 orb->cmd.cpa = virt_to_dma32(cpa);
888 * cp_update_scsw() - update scsw for a channel program.
889 * @cp: channel_program on which to perform the operation
890 * @scsw: I/O results of the channel program and also the target to be
893 * @scsw contains the I/O results of the channel program that pointed
894 * to by @cp. However what @scsw->cpa stores is a host physical
895 * address, which is meaningless for the guest, which is waiting for
898 * This function updates @scsw->cpa to its coressponding guest physical
901 void cp_update_scsw(struct channel_program *cp, union scsw *scsw)
903 struct ccwchain *chain;
904 dma32_t cpa = scsw->cmd.cpa;
907 if (!cp->initialized)
912 * For now, only update the cmd.cpa part. We may need to deal with
913 * other portions of the schib as well, even if we don't return them
914 * in the ioctl directly. Path status changes etc.
916 list_for_each_entry(chain, &cp->ccwchain_list, next) {
917 ccw_head = (u32)(u64)chain->ch_ccw;
919 * On successful execution, cpa points just beyond the end
922 if (is_cpa_within_range(cpa, ccw_head, chain->ch_len + 1)) {
924 * (cpa - ccw_head) is the offset value of the host
925 * physical ccw to its chain head.
926 * Adding this value to the guest physical ccw chain
927 * head gets us the guest cpa:
928 * cpa = chain->ch_iova + (cpa - ccw_head)
930 cpa = dma32_add(cpa, chain->ch_iova - ccw_head);
939 * cp_iova_pinned() - check if an iova is pinned for a ccw chain.
940 * @cp: channel_program on which to perform the operation
941 * @iova: the iova to check
942 * @length: the length to check from @iova
944 * If the @iova is currently pinned for the ccw chain, return true;
947 bool cp_iova_pinned(struct channel_program *cp, u64 iova, u64 length)
949 struct ccwchain *chain;
952 if (!cp->initialized)
955 list_for_each_entry(chain, &cp->ccwchain_list, next) {
956 for (i = 0; i < chain->ch_len; i++)
957 if (page_array_iova_pinned(&chain->ch_pa[i], iova, length))