[PATCH v2 7/9] vfio-ccw: Remove pfn_array_table

Eric Farman
2019-06-06T20:28:41Z

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>
---
drivers/s390/cio/vfio_ccw_cp.c | 118 +++++++++------------------------
1 file changed, 33 insertions(+), 85 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index ab9f8f0d1b44..76ffcc823944 100644
--- 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;
}

--
2.17.1