--- /dev/null
+/*
+ * 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"
+
+/*
+ * Max length for ccw chain.
+ * XXX: Limit to 256, need to check more?
+ */
+#define CCWCHAIN_LEN_MAX 256
+
+struct pfn_array {
+ unsigned long pa_iova;
+ unsigned long *pa_iova_pfn;
+ unsigned long *pa_pfn;
+ int pa_nr;
+};
+
+struct pfn_array_table {
+ struct pfn_array *pat_pa;
+ int pat_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_table *ch_pat;
+};
+
+/*
+ * pfn_array_pin() - pin user pages in memory
+ * @pa: pfn_array on which to perform the operation
+ * @mdev: the mediated device to perform pin/unpin operations
+ *
+ * Attempt to pin user pages in memory.
+ *
+ * Usage of pfn_array:
+ * @pa->pa_iova starting guest physical I/O address. Assigned by caller.
+ * @pa->pa_iova_pfn array that stores PFNs of the pages need to pin. Allocated
+ * by caller.
+ * @pa->pa_pfn array that receives PFNs of the pages pinned. Allocated by
+ * caller.
+ * @pa->pa_nr number of pages from @pa->pa_iova to pin. Assigned by
+ * caller.
+ * number of pages pinned. Assigned by callee.
+ *
+ * Returns:
+ * Number of pages pinned on success.
+ * If @pa->pa_nr is 0 or negative, returns 0.
+ * If no pages were pinned, returns -errno.
+ */
+static int pfn_array_pin(struct pfn_array *pa, struct device *mdev)
+{
+ int i, ret;
+
+ if (pa->pa_nr <= 0) {
+ pa->pa_nr = 0;
+ return 0;
+ }
+
+ pa->pa_iova_pfn[0] = pa->pa_iova >> PAGE_SHIFT;
+ for (i = 1; i < pa->pa_nr; i++)
+ pa->pa_iova_pfn[i] = pa->pa_iova_pfn[i - 1] + 1;
+
+ ret = vfio_pin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr,
+ IOMMU_READ | IOMMU_WRITE, pa->pa_pfn);
+
+ if (ret > 0 && ret != pa->pa_nr) {
+ vfio_unpin_pages(mdev, pa->pa_iova_pfn, ret);
+ pa->pa_nr = 0;
+ return 0;
+ }
+
+ return ret;
+}
+
+/* Unpin the pages before releasing the memory. */
+static void pfn_array_unpin_free(struct pfn_array *pa, struct device *mdev)
+{
+ vfio_unpin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr);
+ pa->pa_nr = 0;
+ kfree(pa->pa_iova_pfn);
+}
+
+/* Alloc memory for PFNs, then pin pages with them. */
+static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev,
+ u64 iova, unsigned int len)
+{
+ int ret = 0;
+
+ if (!len || pa->pa_nr)
+ 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;
+
+ ret = pfn_array_pin(pa, mdev);
+
+ if (ret > 0)
+ return ret;
+ else if (!ret)
+ ret = -EINVAL;
+
+ kfree(pa->pa_iova_pfn);
+
+ return ret;
+}
+
+static int pfn_array_table_init(struct pfn_array_table *pat, int nr)
+{
+ pat->pat_pa = kcalloc(nr, sizeof(*pat->pat_pa), GFP_KERNEL);
+ if (unlikely(ZERO_OR_NULL_PTR(pat->pat_pa))) {
+ pat->pat_nr = 0;
+ return -ENOMEM;
+ }
+
+ pat->pat_nr = nr;
+
+ return 0;
+}
+
+static void pfn_array_table_unpin_free(struct pfn_array_table *pat,
+ struct device *mdev)
+{
+ int i;
+
+ for (i = 0; i < pat->pat_nr; i++)
+ pfn_array_unpin_free(pat->pat_pa + i, mdev);
+
+ if (pat->pat_nr) {
+ kfree(pat->pat_pa);
+ pat->pat_pa = NULL;
+ pat->pat_nr = 0;
+ }
+}
+
+static bool pfn_array_table_iova_pinned(struct pfn_array_table *pat,
+ unsigned long iova)
+{
+ struct pfn_array *pa = pat->pat_pa;
+ unsigned long iova_pfn = iova >> PAGE_SHIFT;
+ int i, j;
+
+ for (i = 0; i < pat->pat_nr; i++, pa++)
+ for (j = 0; j < pa->pa_nr; j++)
+ if (pa->pa_iova_pfn[i] == iova_pfn)
+ return true;
+
+ return false;
+}
+/* Create the list idal words for a pfn_array_table. */
+static inline void pfn_array_table_idal_create_words(
+ struct pfn_array_table *pat,
+ unsigned long *idaws)
+{
+ struct pfn_array *pa;
+ int i, j, k;
+
+ /*
+ * 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.
+ */
+ k = 0;
+ for (i = 0; i < pat->pat_nr; i++) {
+ pa = pat->pat_pa + i;
+ for (j = 0; j < pa->pa_nr; j++) {
+ idaws[k] = pa->pa_pfn[j] << PAGE_SHIFT;
+ if (k == 0)
+ idaws[k] += pa->pa_iova & (PAGE_SIZE - 1);
+ k++;
+ }
+ }
+}
+
+
+/*
+ * 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_pin(&pa, mdev, iova, n);
+ if (ret <= 0)
+ 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;
+}
+
+static long copy_ccw_from_iova(struct channel_program *cp,
+ struct ccw1 *to, u64 iova,
+ unsigned long len)
+{
+ return copy_from_iova(cp->mdev, to, iova, len * sizeof(struct ccw1));
+}
+
+/*
+ * Helpers to operate ccwchain.
+ */
+#define ccw_is_test(_ccw) (((_ccw)->cmd_code & 0x0F) == 0)
+
+#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_chain(_ccw) ((_ccw)->flags & (CCW_FLAG_CC | CCW_FLAG_DC))
+
+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_pat) * 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_pat = (struct pfn_array_table *)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->count)
+ return;
+
+ kfree((void *)(u64)ccw->cda);
+}
+
+/* Unpin the pages then free the memory resources. */
+static void cp_unpin_free(struct channel_program *cp)
+{
+ struct ccwchain *chain, *temp;
+ int i;
+
+ list_for_each_entry_safe(chain, temp, &cp->ccwchain_list, next) {
+ for (i = 0; i < chain->ch_len; i++) {
+ pfn_array_table_unpin_free(chain->ch_pat + i,
+ cp->mdev);
+ ccwchain_cda_free(chain, i);
+ }
+ ccwchain_free(chain);
+ }
+}
+
+/**
+ * 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.
+ *
+ * Returns: the length of the ccw chain or -errno.
+ */
+static int ccwchain_calc_length(u64 iova, struct channel_program *cp)
+{
+ struct ccw1 *ccw, *p;
+ int cnt;
+
+ /*
+ * Copy current chain from guest to host kernel.
+ * Currently the chain length is limited to CCWCHAIN_LEN_MAX (256).
+ * So copying 2K is enough (safe).
+ */
+ p = ccw = kcalloc(CCWCHAIN_LEN_MAX, sizeof(*ccw), GFP_KERNEL);
+ if (!ccw)
+ return -ENOMEM;
+
+ cnt = copy_ccw_from_iova(cp, ccw, iova, CCWCHAIN_LEN_MAX);
+ if (cnt) {
+ kfree(ccw);
+ return cnt;
+ }
+
+ cnt = 0;
+ do {
+ cnt++;
+
+ if ((!ccw_is_chain(ccw)) && (!ccw_is_tic(ccw)))
+ break;
+
+ ccw++;
+ } while (cnt < CCWCHAIN_LEN_MAX + 1);
+
+ if (cnt == CCWCHAIN_LEN_MAX + 1)
+ cnt = -EINVAL;
+
+ kfree(p);
+ return cnt;
+}
+
+static int tic_target_chain_exists(struct ccw1 *tic, struct channel_program *cp)
+{
+ struct ccwchain *chain;
+ u32 ccw_head, ccw_tail;
+
+ list_for_each_entry(chain, &cp->ccwchain_list, next) {
+ ccw_head = chain->ch_iova;
+ ccw_tail = ccw_head + (chain->ch_len - 1) * sizeof(struct ccw1);
+
+ if ((ccw_head <= tic->cda) && (tic->cda <= ccw_tail))
+ return 1;
+ }
+
+ return 0;
+}
+
+static int ccwchain_loop_tic(struct ccwchain *chain,
+ struct channel_program *cp);
+
+static int ccwchain_handle_tic(struct ccw1 *tic, struct channel_program *cp)
+{
+ struct ccwchain *chain;
+ int len, ret;
+
+ /* May transfer to an existing chain. */
+ if (tic_target_chain_exists(tic, cp))
+ return 0;
+
+ /* Get chain length. */
+ len = ccwchain_calc_length(tic->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 = tic->cda;
+
+ /* Copy the new chain from user. */
+ ret = copy_ccw_from_iova(cp, chain->ch_ccw, tic->cda, len);
+ if (ret) {
+ ccwchain_free(chain);
+ return ret;
+ }
+
+ /* 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;
+
+ ret = ccwchain_handle_tic(tic, 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, ccw_tail;
+
+ list_for_each_entry(iter, &cp->ccwchain_list, next) {
+ ccw_head = iter->ch_iova;
+ ccw_tail = ccw_head + (iter->ch_len - 1) * sizeof(struct ccw1);
+
+ if ((ccw_head <= ccw->cda) && (ccw->cda <= ccw_tail)) {
+ ccw->cda = (__u32) (addr_t) (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_table *pat;
+ unsigned long *idaws;
+ int idaw_nr;
+
+ ccw = chain->ch_ccw + idx;
+
+ /*
+ * Pin data page(s) in memory.
+ * The number of pages actually is the count of the idaws which will be
+ * needed when translating a direct ccw to a idal ccw.
+ */
+ pat = chain->ch_pat + idx;
+ if (pfn_array_table_init(pat, 1))
+ return -ENOMEM;
+ idaw_nr = pfn_array_alloc_pin(pat->pat_pa, cp->mdev,
+ ccw->cda, ccw->count);
+ if (idaw_nr < 0)
+ return idaw_nr;
+
+ /* Translate this direct ccw to a idal ccw. */
+ idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
+ if (!idaws) {
+ pfn_array_table_unpin_free(pat, cp->mdev);
+ return -ENOMEM;
+ }
+ ccw->cda = (__u32) virt_to_phys(idaws);
+ ccw->flags |= CCW_FLAG_IDA;
+
+ pfn_array_table_idal_create_words(pat, idaws);
+
+ return 0;
+}
+
+static int ccwchain_fetch_idal(struct ccwchain *chain,
+ int idx,
+ struct channel_program *cp)
+{
+ struct ccw1 *ccw;
+ struct pfn_array_table *pat;
+ unsigned long *idaws;
+ u64 idaw_iova;
+ unsigned int idaw_nr, idaw_len;
+ int i, ret;
+
+ ccw = chain->ch_ccw + idx;
+
+ /* Calculate size of idaws. */
+ ret = copy_from_iova(cp->mdev, &idaw_iova, ccw->cda, sizeof(idaw_iova));
+ if (ret)
+ return ret;
+ idaw_nr = idal_nr_words((void *)(idaw_iova), ccw->count);
+ idaw_len = idaw_nr * sizeof(*idaws);
+
+ /* Pin data page(s) in memory. */
+ pat = chain->ch_pat + idx;
+ ret = pfn_array_table_init(pat, idaw_nr);
+ if (ret)
+ return ret;
+
+ /* Translate idal ccw to use new allocated idaws. */
+ idaws = kzalloc(idaw_len, GFP_DMA | GFP_KERNEL);
+ if (!idaws) {
+ ret = -ENOMEM;
+ goto out_unpin;
+ }
+
+ ret = copy_from_iova(cp->mdev, idaws, ccw->cda, idaw_len);
+ if (ret)
+ goto out_free_idaws;
+
+ ccw->cda = virt_to_phys(idaws);
+
+ for (i = 0; i < idaw_nr; i++) {
+ idaw_iova = *(idaws + i);
+ if (IS_ERR_VALUE(idaw_iova)) {
+ ret = -EFAULT;
+ goto out_free_idaws;
+ }
+
+ ret = pfn_array_alloc_pin(pat->pat_pa + i, cp->mdev,
+ idaw_iova, 1);
+ if (ret < 0)
+ goto out_free_idaws;
+ }
+
+ pfn_array_table_idal_create_words(pat, idaws);
+
+ return 0;
+
+out_free_idaws:
+ kfree(idaws);
+out_unpin:
+ pfn_array_table_unpin_free(pat, cp->mdev);
+ 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_test(ccw) || ccw_is_noop(ccw))
+ return 0;
+
+ if (ccw_is_tic(ccw))
+ return ccwchain_fetch_tic(chain, idx, cp);
+
+ if (ccw_is_idal(ccw))
+ return ccwchain_fetch_idal(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)
+{
+ u64 iova = orb->cmd.cpa;
+ struct ccwchain *chain;
+ int len, ret;
+
+ /*
+ * XXX:
+ * Only support prefetch enable mode now.
+ * Only support 64bit addressing idal.
+ * Only support 4k IDAW.
+ * Only support ccw1.
+ */
+ if (!orb->cmd.pfch || !orb->cmd.c64 || orb->cmd.i2k || !orb->cmd.fmt)
+ return -EOPNOTSUPP;
+
+ INIT_LIST_HEAD(&cp->ccwchain_list);
+ memcpy(&cp->orb, orb, sizeof(*orb));
+ cp->mdev = mdev;
+
+ /* Get chain length. */
+ len = ccwchain_calc_length(iova, cp);
+ if (len < 0)
+ return len;
+
+ /* Alloc mem for the head chain. */
+ chain = ccwchain_alloc(cp, len);
+ if (!chain)
+ return -ENOMEM;
+ chain->ch_iova = iova;
+
+ /* Copy the head chain from guest. */
+ ret = copy_ccw_from_iova(cp, chain->ch_ccw, iova, len);
+ if (ret) {
+ ccwchain_free(chain);
+ return ret;
+ }
+
+ /* Now loop for its TICs. */
+ ret = ccwchain_loop_tic(chain, cp);
+ if (ret)
+ cp_unpin_free(cp);
+
+ 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)
+{
+ cp_unpin_free(cp);
+}
+
+/**
+ * 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.
+ *
+ * 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;
+
+ 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)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * 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;
+
+ 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, ccw_tail;
+
+ /*
+ * 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;
+ ccw_tail = (u32)(u64)(chain->ch_ccw + chain->ch_len - 1);
+
+ if ((ccw_head <= cpa) && (cpa <= ccw_tail)) {
+ /*
+ * (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.
+ * @cmd: ccwchain command 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;
+
+ list_for_each_entry(chain, &cp->ccwchain_list, next) {
+ for (i = 0; i < chain->ch_len; i++)
+ if (pfn_array_table_iova_pinned(chain->ch_pat + i,
+ iova))
+ return true;
+ }
+
+ return false;
+}
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff