vfio-ccw: Remove pfn_array_table

Now that both CCW codepaths build this nested array:

  ccwchain->pfn_array_table[1]->pfn_array[#idaws/#pages]

We can collapse this into simply:

  ccwchain->pfn_array[#idaws/#pages]

Let's do that, so that we don't have to continually navigate two
nested arrays when the first array always has a count of one.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20190606202831.44135-8-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index ab9f8f0..76ffcc8 100644 (file)
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -33,11 +33,6 @@ struct pfn_array {
        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;
@@ -46,7 +41,7 @@ struct ccwchain {
        /* Count of the valid ccws in chain. */
        int                     ch_len;
        /* Pinned PAGEs for the original data. */
-       struct pfn_array_table  *ch_pat;
+       struct pfn_array        *ch_pa;
 };
 
 /*
@@ -139,55 +134,23 @@ static void pfn_array_unpin_free(struct pfn_array *pa, struct device *mdev)
        kfree(pa->pa_iova_pfn);
 }
 
-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)
+static bool pfn_array_iova_pinned(struct pfn_array *pa, unsigned long iova)
 {
-       struct pfn_array *pa = pat->pat_pa;
        unsigned long iova_pfn = iova >> PAGE_SHIFT;
-       int i, j;
+       int i;
 
-       for (i = 0; i < pat->pat_nr; i++, pa++)
-               for (j = 0; j < pa->pa_nr; j++)
-                       if (pa->pa_iova_pfn[j] == iova_pfn)
-                               return true;
+       for (i = 0; i < pa->pa_nr; i++)
+               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,
+/* 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)
 {
-       struct pfn_array *pa;
-       int i, j, k;
+       int i;
 
        /*
         * Idal words (execept the first one) rely on the memory being 4k
@@ -196,17 +159,12 @@ static inline void pfn_array_table_idal_create_words(
         * 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;
-                       k++;
-               }
-       }
+
+       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] += pat->pat_pa->pa_iova & (PAGE_SIZE - 1);
+       idaws[0] += pa->pa_iova & (PAGE_SIZE - 1);
 }
 
 
@@ -378,7 +336,7 @@ static struct ccwchain *ccwchain_alloc(struct channel_program *cp, int len)
        /* Make ccw address aligned to 8. */
        size = ((sizeof(*chain) + 7L) & -8L) +
                sizeof(*chain->ch_ccw) * len +
-               sizeof(*chain->ch_pat) * len;
+               sizeof(*chain->ch_pa) * len;
        chain = kzalloc(size, GFP_DMA | GFP_KERNEL);
        if (!chain)
                return NULL;
@@ -387,7 +345,7 @@ static struct ccwchain *ccwchain_alloc(struct channel_program *cp, int len)
        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_pa = (struct pfn_array *)data;
 
        chain->ch_len = len;
 
@@ -575,7 +533,7 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
                                 struct channel_program *cp)
 {
        struct ccw1 *ccw;
-       struct pfn_array_table *pat;
+       struct pfn_array *pa;
        unsigned long *idaws;
        int ret;
        int bytes = 1;
@@ -593,21 +551,17 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
         * 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;
-       ret = pfn_array_table_init(pat, 1);
-       if (ret)
-               goto out_init;
-
-       ret = pfn_array_alloc(pat->pat_pa, ccw->cda, bytes);
+       pa = chain->ch_pa + idx;
+       ret = pfn_array_alloc(pa, ccw->cda, bytes);
        if (ret < 0)
                goto out_unpin;
 
        if (ccw_does_data_transfer(ccw)) {
-               ret = pfn_array_pin(pat->pat_pa, cp->mdev);
+               ret = pfn_array_pin(pa, cp->mdev);
                if (ret < 0)
                        goto out_unpin;
        } else {
-               pat->pat_pa->pa_nr = 0;
+               pa->pa_nr = 0;
        }
 
        /* Translate this direct ccw to a idal ccw. */
@@ -619,12 +573,12 @@ static int ccwchain_fetch_direct(struct ccwchain *chain,
        ccw->cda = (__u32) virt_to_phys(idaws);
        ccw->flags |= CCW_FLAG_IDA;
 
-       pfn_array_table_idal_create_words(pat, idaws);
+       pfn_array_idal_create_words(pa, idaws);
 
        return 0;
 
 out_unpin:
-       pfn_array_table_unpin_free(pat, cp->mdev);
+       pfn_array_unpin_free(pa, cp->mdev);
 out_init:
        ccw->cda = 0;
        return ret;
@@ -635,7 +589,7 @@ static int ccwchain_fetch_idal(struct ccwchain *chain,
                               struct channel_program *cp)
 {
        struct ccw1 *ccw;
-       struct pfn_array_table *pat;
+       struct pfn_array *pa;
        unsigned long *idaws;
        u64 idaw_iova;
        unsigned int idaw_nr, idaw_len;
@@ -655,15 +609,11 @@ static int ccwchain_fetch_idal(struct ccwchain *chain,
        idaw_len = idaw_nr * sizeof(*idaws);
 
        /* Pin data page(s) in memory. */
-       pat = chain->ch_pat + idx;
-       ret = pfn_array_table_init(pat, 1);
+       pa = chain->ch_pa + idx;
+       ret = pfn_array_alloc(pa, idaw_iova, bytes);
        if (ret)
                goto out_init;
 
-       ret = pfn_array_alloc(pat->pat_pa, idaw_iova, bytes);
-       if (ret)
-               goto out_unpin;
-
        /* Translate idal ccw to use new allocated idaws. */
        idaws = kzalloc(idaw_len, GFP_DMA | GFP_KERNEL);
        if (!idaws) {
@@ -678,24 +628,24 @@ static int ccwchain_fetch_idal(struct ccwchain *chain,
        ccw->cda = virt_to_phys(idaws);
 
        for (i = 0; i < idaw_nr; i++)
-               pat->pat_pa->pa_iova_pfn[i] = idaws[i] >> PAGE_SHIFT;
+               pa->pa_iova_pfn[i] = idaws[i] >> PAGE_SHIFT;
 
        if (ccw_does_data_transfer(ccw)) {
-               ret = pfn_array_pin(pat->pat_pa, cp->mdev);
+               ret = pfn_array_pin(pa, cp->mdev);
                if (ret < 0)
                        goto out_free_idaws;
        } else {
-               pat->pat_pa->pa_nr = 0;
+               pa->pa_nr = 0;
        }
 
-       pfn_array_table_idal_create_words(pat, idaws);
+       pfn_array_idal_create_words(pa, idaws);
 
        return 0;
 
 out_free_idaws:
        kfree(idaws);
 out_unpin:
-       pfn_array_table_unpin_free(pat, cp->mdev);
+       pfn_array_unpin_free(pa, cp->mdev);
 out_init:
        ccw->cda = 0;
        return ret;
@@ -790,8 +740,7 @@ void cp_free(struct channel_program *cp)
        cp->initialized = false;
        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);
+                       pfn_array_unpin_free(chain->ch_pa + i, cp->mdev);
                        ccwchain_cda_free(chain, i);
                }
                ccwchain_free(chain);
@@ -967,8 +916,7 @@ bool cp_iova_pinned(struct channel_program *cp, u64 iova)
 
        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))
+                       if (pfn_array_iova_pinned(chain->ch_pa + i, iova))
                                return true;
        }