[Intel-gfx] [PATCH 06/46] drm/i915: Add some selftests for sg_table manipulation
Tvrtko Ursulin
tvrtko.ursulin at linux.intel.com
Fri Feb 10 10:24:41 UTC 2017
On 02/02/2017 09:08, Chris Wilson wrote:
> 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()
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
> drivers/gpu/drm/i915/i915_gem.c | 11 +-
> .../gpu/drm/i915/selftests/i915_mock_selftests.h | 1 +
> drivers/gpu/drm/i915/selftests/scatterlist.c | 331 +++++++++++++++++++++
> 3 files changed, 340 insertions(+), 3 deletions(-)
> create mode 100644 drivers/gpu/drm/i915/selftests/scatterlist.c
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 88065fd55147..fc54a8eb3fe5 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2216,17 +2216,17 @@ void __i915_gem_object_put_pages(struct drm_i915_gem_object *obj,
> 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 scatterlist *sg, *new_sg;
> unsigned int i;
>
> if (orig_st->nents == orig_st->orig_nents)
> - return;
> + return false;
>
> if (sg_alloc_table(&new_st, orig_st->nents, GFP_KERNEL | __GFP_NOWARN))
> - return;
> + return false;
>
> new_sg = new_st.sgl;
> for_each_sg(orig_st->sgl, sg, orig_st->nents, i) {
> @@ -2239,6 +2239,7 @@ static void i915_sg_trim(struct sg_table *orig_st)
> sg_free_table(orig_st);
>
> *orig_st = new_st;
> + return true;
> }
>
> static struct sg_table *
> @@ -4967,3 +4968,7 @@ i915_gem_object_get_dma_address(struct drm_i915_gem_object *obj,
> sg = i915_gem_object_get_sg(obj, n, &offset);
> return sg_dma_address(sg) + (offset << PAGE_SHIFT);
> }
> +
> +#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
> +#include "selftests/scatterlist.c"
> +#endif
> diff --git a/drivers/gpu/drm/i915/selftests/i915_mock_selftests.h b/drivers/gpu/drm/i915/selftests/i915_mock_selftests.h
> index 69e97a2ba4a6..5f0bdda42ed8 100644
> --- a/drivers/gpu/drm/i915/selftests/i915_mock_selftests.h
> +++ b/drivers/gpu/drm/i915/selftests/i915_mock_selftests.h
> @@ -9,3 +9,4 @@
> * Tests are executed in order by igt/drv_selftest
> */
> selftest(sanitycheck, i915_mock_sanitycheck) /* keep first (igt selfcheck) */
> +selftest(scatterlist, scatterlist_mock_selftests)
> diff --git a/drivers/gpu/drm/i915/selftests/scatterlist.c b/drivers/gpu/drm/i915/selftests/scatterlist.c
> new file mode 100644
> index 000000000000..fa5bd09c863f
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/selftests/scatterlist.c
> @@ -0,0 +1,331 @@
> +/*
> + * 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 bool alloc_table(struct pfn_table *pt,
> + unsigned long count, unsigned long max,
> + npages_fn_t npages_fn,
> + struct rnd_state *rnd)
> +{
> + struct scatterlist *sg;
> + unsigned long n, pfn;
> +
> + if (sg_alloc_table(&pt->st, max,
> + GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN))
> + return false;
> +
> + /* 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);
> +
> + 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 true;
> +}
> +
> +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;
> +
> + 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);
> + if (!alloc_table(&pt, sz, sz, *npages, &prng))
> + return 0; /* out of memory, give up */
We need to define at least some amount of testing which must pass
otherwise it is just too weak in my opinion.
return prime < TBD ? -Esomething : 0;
?
Regards,
Tvrtko
> +
> + 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;
> + }
> + }
> + }
> +
> + 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;
> +
> + 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);
> + if (!alloc_table(&pt, prime, max, *npages, &prng))
> + return 0; /* out of memory, give up */
> +
> + err = 0;
> + 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;
> + }
> + }
> +
> + 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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