Commit 935a2f77 authored by Chris Wilson's avatar Chris Wilson

drm/i915: Add some selftests for sg_table manipulation

Start exercising the scattergather lists, especially looking at
iteration after coalescing.

v2: Comment on the peculiarity of table construction (i.e. why this
sg_table might be interesting).
v3: Added one __func__ to identify expect_pfn_sg()
v4: Loop until we have crossed the chain boundary (forcing sg_table to
do multiple allocations) before squelching a potential ENOMEM from oom.
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-2-chris@chris-wilson.co.uk
parent 953c7f82
...@@ -2224,17 +2224,17 @@ void __i915_gem_object_put_pages(struct drm_i915_gem_object *obj, ...@@ -2224,17 +2224,17 @@ void __i915_gem_object_put_pages(struct drm_i915_gem_object *obj,
mutex_unlock(&obj->mm.lock); mutex_unlock(&obj->mm.lock);
} }
static void i915_sg_trim(struct sg_table *orig_st) static bool i915_sg_trim(struct sg_table *orig_st)
{ {
struct sg_table new_st; struct sg_table new_st;
struct scatterlist *sg, *new_sg; struct scatterlist *sg, *new_sg;
unsigned int i; unsigned int i;
if (orig_st->nents == orig_st->orig_nents) if (orig_st->nents == orig_st->orig_nents)
return; return false;
if (sg_alloc_table(&new_st, orig_st->nents, GFP_KERNEL | __GFP_NOWARN)) if (sg_alloc_table(&new_st, orig_st->nents, GFP_KERNEL | __GFP_NOWARN))
return; return false;
new_sg = new_st.sgl; new_sg = new_st.sgl;
for_each_sg(orig_st->sgl, sg, orig_st->nents, i) { for_each_sg(orig_st->sgl, sg, orig_st->nents, i) {
...@@ -2247,6 +2247,7 @@ static void i915_sg_trim(struct sg_table *orig_st) ...@@ -2247,6 +2247,7 @@ static void i915_sg_trim(struct sg_table *orig_st)
sg_free_table(orig_st); sg_free_table(orig_st);
*orig_st = new_st; *orig_st = new_st;
return true;
} }
static struct sg_table * static struct sg_table *
...@@ -5019,3 +5020,7 @@ i915_gem_object_get_dma_address(struct drm_i915_gem_object *obj, ...@@ -5019,3 +5020,7 @@ i915_gem_object_get_dma_address(struct drm_i915_gem_object *obj,
sg = i915_gem_object_get_sg(obj, n, &offset); sg = i915_gem_object_get_sg(obj, n, &offset);
return sg_dma_address(sg) + (offset << PAGE_SHIFT); return sg_dma_address(sg) + (offset << PAGE_SHIFT);
} }
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftests/scatterlist.c"
#endif
...@@ -9,3 +9,4 @@ ...@@ -9,3 +9,4 @@
* Tests are executed in order by igt/drv_selftest * Tests are executed in order by igt/drv_selftest
*/ */
selftest(sanitycheck, i915_mock_sanitycheck) /* keep first (igt selfcheck) */ selftest(sanitycheck, i915_mock_sanitycheck) /* keep first (igt selfcheck) */
selftest(scatterlist, scatterlist_mock_selftests)
/*
* Copyright © 2016 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <linux/prime_numbers.h>
#include <linux/random.h>
#include "../i915_selftest.h"
#define PFN_BIAS (1 << 10)
struct pfn_table {
struct sg_table st;
unsigned long start, end;
};
typedef unsigned int (*npages_fn_t)(unsigned long n,
unsigned long count,
struct rnd_state *rnd);
static noinline int expect_pfn_sg(struct pfn_table *pt,
npages_fn_t npages_fn,
struct rnd_state *rnd,
const char *who,
unsigned long timeout)
{
struct scatterlist *sg;
unsigned long pfn, n;
pfn = pt->start;
for_each_sg(pt->st.sgl, sg, pt->st.nents, n) {
struct page *page = sg_page(sg);
unsigned int npages = npages_fn(n, pt->st.nents, rnd);
if (page_to_pfn(page) != pfn) {
pr_err("%s: %s left pages out of order, expected pfn %lu, found pfn %lu (using for_each_sg)\n",
__func__, who, pfn, page_to_pfn(page));
return -EINVAL;
}
if (sg->length != npages * PAGE_SIZE) {
pr_err("%s: %s copied wrong sg length, expected size %lu, found %u (using for_each_sg)\n",
__func__, who, npages * PAGE_SIZE, sg->length);
return -EINVAL;
}
if (igt_timeout(timeout, "%s timed out\n", who))
return -EINTR;
pfn += npages;
}
if (pfn != pt->end) {
pr_err("%s: %s finished on wrong pfn, expected %lu, found %lu\n",
__func__, who, pt->end, pfn);
return -EINVAL;
}
return 0;
}
static noinline int expect_pfn_sg_page_iter(struct pfn_table *pt,
const char *who,
unsigned long timeout)
{
struct sg_page_iter sgiter;
unsigned long pfn;
pfn = pt->start;
for_each_sg_page(pt->st.sgl, &sgiter, pt->st.nents, 0) {
struct page *page = sg_page_iter_page(&sgiter);
if (page != pfn_to_page(pfn)) {
pr_err("%s: %s left pages out of order, expected pfn %lu, found pfn %lu (using for_each_sg_page)\n",
__func__, who, pfn, page_to_pfn(page));
return -EINVAL;
}
if (igt_timeout(timeout, "%s timed out\n", who))
return -EINTR;
pfn++;
}
if (pfn != pt->end) {
pr_err("%s: %s finished on wrong pfn, expected %lu, found %lu\n",
__func__, who, pt->end, pfn);
return -EINVAL;
}
return 0;
}
static noinline int expect_pfn_sgtiter(struct pfn_table *pt,
const char *who,
unsigned long timeout)
{
struct sgt_iter sgt;
struct page *page;
unsigned long pfn;
pfn = pt->start;
for_each_sgt_page(page, sgt, &pt->st) {
if (page != pfn_to_page(pfn)) {
pr_err("%s: %s left pages out of order, expected pfn %lu, found pfn %lu (using for_each_sgt_page)\n",
__func__, who, pfn, page_to_pfn(page));
return -EINVAL;
}
if (igt_timeout(timeout, "%s timed out\n", who))
return -EINTR;
pfn++;
}
if (pfn != pt->end) {
pr_err("%s: %s finished on wrong pfn, expected %lu, found %lu\n",
__func__, who, pt->end, pfn);
return -EINVAL;
}
return 0;
}
static int expect_pfn_sgtable(struct pfn_table *pt,
npages_fn_t npages_fn,
struct rnd_state *rnd,
const char *who,
unsigned long timeout)
{
int err;
err = expect_pfn_sg(pt, npages_fn, rnd, who, timeout);
if (err)
return err;
err = expect_pfn_sg_page_iter(pt, who, timeout);
if (err)
return err;
err = expect_pfn_sgtiter(pt, who, timeout);
if (err)
return err;
return 0;
}
static unsigned int one(unsigned long n,
unsigned long count,
struct rnd_state *rnd)
{
return 1;
}
static unsigned int grow(unsigned long n,
unsigned long count,
struct rnd_state *rnd)
{
return n + 1;
}
static unsigned int shrink(unsigned long n,
unsigned long count,
struct rnd_state *rnd)
{
return count - n;
}
static unsigned int random(unsigned long n,
unsigned long count,
struct rnd_state *rnd)
{
return 1 + (prandom_u32_state(rnd) % 1024);
}
static int alloc_table(struct pfn_table *pt,
unsigned long count, unsigned long max,
npages_fn_t npages_fn,
struct rnd_state *rnd,
int alloc_error)
{
struct scatterlist *sg;
unsigned long n, pfn;
if (sg_alloc_table(&pt->st, max,
GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN))
return alloc_error;
/* count should be less than 20 to prevent overflowing sg->length */
GEM_BUG_ON(overflows_type(count * PAGE_SIZE, sg->length));
/* Construct a table where each scatterlist contains different number
* of entries. The idea is to check that we can iterate the individual
* pages from inside the coalesced lists.
*/
pt->start = PFN_BIAS;
pfn = pt->start;
sg = pt->st.sgl;
for (n = 0; n < count; n++) {
unsigned long npages = npages_fn(n, count, rnd);
/* Nobody expects the Sparse Memmap! */
if (pfn_to_page(pfn + npages) != pfn_to_page(pfn) + npages) {
sg_free_table(&pt->st);
return -ENOSPC;
}
if (n)
sg = sg_next(sg);
sg_set_page(sg, pfn_to_page(pfn), npages * PAGE_SIZE, 0);
GEM_BUG_ON(page_to_pfn(sg_page(sg)) != pfn);
GEM_BUG_ON(sg->length != npages * PAGE_SIZE);
GEM_BUG_ON(sg->offset != 0);
pfn += npages;
}
sg_mark_end(sg);
pt->st.nents = n;
pt->end = pfn;
return 0;
}
static const npages_fn_t npages_funcs[] = {
one,
grow,
shrink,
random,
NULL,
};
static int igt_sg_alloc(void *ignored)
{
IGT_TIMEOUT(end_time);
const unsigned long max_order = 20; /* approximating a 4GiB object */
struct rnd_state prng;
unsigned long prime;
int alloc_error = -ENOMEM;
for_each_prime_number(prime, max_order) {
unsigned long size = BIT(prime);
int offset;
for (offset = -1; offset <= 1; offset++) {
unsigned long sz = size + offset;
const npages_fn_t *npages;
struct pfn_table pt;
int err;
for (npages = npages_funcs; *npages; npages++) {
prandom_seed_state(&prng,
i915_selftest.random_seed);
err = alloc_table(&pt, sz, sz, *npages, &prng,
alloc_error);
if (err == -ENOSPC)
break;
if (err)
return err;
prandom_seed_state(&prng,
i915_selftest.random_seed);
err = expect_pfn_sgtable(&pt, *npages, &prng,
"sg_alloc_table",
end_time);
sg_free_table(&pt.st);
if (err)
return err;
}
}
/* Test at least one continuation before accepting oom */
if (size > SG_MAX_SINGLE_ALLOC)
alloc_error = -ENOSPC;
}
return 0;
}
static int igt_sg_trim(void *ignored)
{
IGT_TIMEOUT(end_time);
const unsigned long max = PAGE_SIZE; /* not prime! */
struct pfn_table pt;
unsigned long prime;
int alloc_error = -ENOMEM;
for_each_prime_number(prime, max) {
const npages_fn_t *npages;
int err;
for (npages = npages_funcs; *npages; npages++) {
struct rnd_state prng;
prandom_seed_state(&prng, i915_selftest.random_seed);
err = alloc_table(&pt, prime, max, *npages, &prng,
alloc_error);
if (err == -ENOSPC)
break;
if (err)
return err;
if (i915_sg_trim(&pt.st)) {
if (pt.st.orig_nents != prime ||
pt.st.nents != prime) {
pr_err("i915_sg_trim failed (nents %u, orig_nents %u), expected %lu\n",
pt.st.nents, pt.st.orig_nents, prime);
err = -EINVAL;
} else {
prandom_seed_state(&prng,
i915_selftest.random_seed);
err = expect_pfn_sgtable(&pt,
*npages, &prng,
"i915_sg_trim",
end_time);
}
}
sg_free_table(&pt.st);
if (err)
return err;
}
/* Test at least one continuation before accepting oom */
if (prime > SG_MAX_SINGLE_ALLOC)
alloc_error = -ENOSPC;
}
return 0;
}
int scatterlist_mock_selftests(void)
{
static const struct i915_subtest tests[] = {
SUBTEST(igt_sg_alloc),
SUBTEST(igt_sg_trim),
};
return i915_subtests(tests, NULL);
}
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