[Intel-gfx] [CI 21/47] drm/i915: Test coherency of and barriers between cache domains
Chris Wilson
chris at chris-wilson.co.uk
Mon Feb 13 17:15:32 UTC 2017
Write into an object using WB, WC, GTT, and GPU paths and make sure that
our internal API is sufficient to ensure coherent reads and writes.
v2: Avoid invalid free upon allocation error
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld at intel.com>
---
drivers/gpu/drm/i915/i915_gem.c | 1 +
drivers/gpu/drm/i915/i915_selftest.h | 2 +
.../gpu/drm/i915/selftests/i915_gem_coherency.c | 384 +++++++++++++++++++++
.../gpu/drm/i915/selftests/i915_live_selftests.h | 1 +
4 files changed, 388 insertions(+)
create mode 100644 drivers/gpu/drm/i915/selftests/i915_gem_coherency.c
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ec455f47958a..82489ed10373 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5026,4 +5026,5 @@ i915_gem_object_get_dma_address(struct drm_i915_gem_object *obj,
#include "selftests/mock_gem_device.c"
#include "selftests/huge_gem_object.c"
#include "selftests/i915_gem_object.c"
+#include "selftests/i915_gem_coherency.c"
#endif
diff --git a/drivers/gpu/drm/i915/i915_selftest.h b/drivers/gpu/drm/i915/i915_selftest.h
index 8b5994caa301..e43777b72211 100644
--- a/drivers/gpu/drm/i915/i915_selftest.h
+++ b/drivers/gpu/drm/i915/i915_selftest.h
@@ -99,4 +99,6 @@ bool __igt_timeout(unsigned long timeout, const char *fmt, ...);
#define igt_timeout(t, fmt, ...) \
__igt_timeout((t), KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
+#define igt_can_mi_store_dword_imm(D) (INTEL_GEN(D) > 2)
+
#endif /* !__I915_SELFTEST_H__ */
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c b/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c
new file mode 100644
index 000000000000..483cbe02d983
--- /dev/null
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c
@@ -0,0 +1,384 @@
+/*
+ * Copyright © 2017 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 "../i915_selftest.h"
+#include "i915_random.h"
+
+static int cpu_set(struct drm_i915_gem_object *obj,
+ unsigned long offset,
+ u32 v)
+{
+ unsigned int needs_clflush;
+ struct page *page;
+ typeof(v) *map;
+ int err;
+
+ err = i915_gem_obj_prepare_shmem_write(obj, &needs_clflush);
+ if (err)
+ return err;
+
+ page = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT);
+ map = kmap_atomic(page);
+ if (needs_clflush & CLFLUSH_BEFORE)
+ clflush(map+offset_in_page(offset) / sizeof(*map));
+ map[offset_in_page(offset) / sizeof(*map)] = v;
+ if (needs_clflush & CLFLUSH_AFTER)
+ clflush(map+offset_in_page(offset) / sizeof(*map));
+ kunmap_atomic(map);
+
+ i915_gem_obj_finish_shmem_access(obj);
+ return 0;
+}
+
+static int cpu_get(struct drm_i915_gem_object *obj,
+ unsigned long offset,
+ u32 *v)
+{
+ unsigned int needs_clflush;
+ struct page *page;
+ typeof(v) map;
+ int err;
+
+ err = i915_gem_obj_prepare_shmem_read(obj, &needs_clflush);
+ if (err)
+ return err;
+
+ page = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT);
+ map = kmap_atomic(page);
+ if (needs_clflush & CLFLUSH_BEFORE)
+ clflush(map+offset_in_page(offset) / sizeof(*map));
+ *v = map[offset_in_page(offset) / sizeof(*map)];
+ kunmap_atomic(map);
+
+ i915_gem_obj_finish_shmem_access(obj);
+ return 0;
+}
+
+static int gtt_set(struct drm_i915_gem_object *obj,
+ unsigned long offset,
+ u32 v)
+{
+ struct i915_vma *vma;
+ typeof(v) *map;
+ int err;
+
+ err = i915_gem_object_set_to_gtt_domain(obj, true);
+ if (err)
+ return err;
+
+ vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE);
+ if (IS_ERR(vma))
+ return PTR_ERR(vma);
+
+ map = i915_vma_pin_iomap(vma);
+ i915_vma_unpin(vma);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ map[offset / sizeof(*map)] = v;
+ i915_vma_unpin_iomap(vma);
+
+ return 0;
+}
+
+static int gtt_get(struct drm_i915_gem_object *obj,
+ unsigned long offset,
+ u32 *v)
+{
+ struct i915_vma *vma;
+ typeof(v) map;
+ int err;
+
+ err = i915_gem_object_set_to_gtt_domain(obj, false);
+ if (err)
+ return err;
+
+ vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE);
+ if (IS_ERR(vma))
+ return PTR_ERR(vma);
+
+ map = i915_vma_pin_iomap(vma);
+ i915_vma_unpin(vma);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ *v = map[offset / sizeof(*map)];
+ i915_vma_unpin_iomap(vma);
+
+ return 0;
+}
+
+static int wc_set(struct drm_i915_gem_object *obj,
+ unsigned long offset,
+ u32 v)
+{
+ typeof(v) *map;
+ int err;
+
+ /* XXX GTT write followed by WC write go missing */
+ i915_gem_object_flush_gtt_write_domain(obj);
+
+ err = i915_gem_object_set_to_gtt_domain(obj, true);
+ if (err)
+ return err;
+
+ map = i915_gem_object_pin_map(obj, I915_MAP_WC);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ map[offset / sizeof(*map)] = v;
+ i915_gem_object_unpin_map(obj);
+
+ return 0;
+}
+
+static int wc_get(struct drm_i915_gem_object *obj,
+ unsigned long offset,
+ u32 *v)
+{
+ typeof(v) map;
+ int err;
+
+ /* XXX WC write followed by GTT write go missing */
+ i915_gem_object_flush_gtt_write_domain(obj);
+
+ err = i915_gem_object_set_to_gtt_domain(obj, false);
+ if (err)
+ return err;
+
+ map = i915_gem_object_pin_map(obj, I915_MAP_WC);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ *v = map[offset / sizeof(*map)];
+ i915_gem_object_unpin_map(obj);
+
+ return 0;
+}
+
+static int gpu_set(struct drm_i915_gem_object *obj,
+ unsigned long offset,
+ u32 v)
+{
+ struct drm_i915_private *i915 = to_i915(obj->base.dev);
+ struct drm_i915_gem_request *rq;
+ struct i915_vma *vma;
+ int err;
+
+ err = i915_gem_object_set_to_gtt_domain(obj, true);
+ if (err)
+ return err;
+
+ vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
+ if (IS_ERR(vma))
+ return PTR_ERR(vma);
+
+ rq = i915_gem_request_alloc(i915->engine[RCS], i915->kernel_context);
+ if (IS_ERR(rq)) {
+ i915_vma_unpin(vma);
+ return PTR_ERR(rq);
+ }
+
+ err = intel_ring_begin(rq, 4);
+ if (err) {
+ __i915_add_request(rq, false);
+ i915_vma_unpin(vma);
+ return err;
+ }
+
+ if (INTEL_GEN(i915) >= 8) {
+ intel_ring_emit(rq->ring, MI_STORE_DWORD_IMM_GEN4 | 1 << 22);
+ intel_ring_emit(rq->ring, lower_32_bits(i915_ggtt_offset(vma) + offset));
+ intel_ring_emit(rq->ring, upper_32_bits(i915_ggtt_offset(vma) + offset));
+ intel_ring_emit(rq->ring, v);
+ } else if (INTEL_GEN(i915) >= 4) {
+ intel_ring_emit(rq->ring, MI_STORE_DWORD_IMM_GEN4 | 1 << 22);
+ intel_ring_emit(rq->ring, 0);
+ intel_ring_emit(rq->ring, i915_ggtt_offset(vma) + offset);
+ intel_ring_emit(rq->ring, v);
+ } else {
+ intel_ring_emit(rq->ring, MI_STORE_DWORD_IMM | 1 << 22);
+ intel_ring_emit(rq->ring, i915_ggtt_offset(vma) + offset);
+ intel_ring_emit(rq->ring, v);
+ intel_ring_emit(rq->ring, MI_NOOP);
+ }
+ intel_ring_advance(rq->ring);
+
+ i915_vma_move_to_active(vma, rq, EXEC_OBJECT_WRITE);
+ i915_vma_unpin(vma);
+
+ reservation_object_lock(obj->resv, NULL);
+ reservation_object_add_excl_fence(obj->resv, &rq->fence);
+ reservation_object_unlock(obj->resv);
+
+ __i915_add_request(rq, true);
+
+ return 0;
+}
+
+static bool always_valid(struct drm_i915_private *i915)
+{
+ return true;
+}
+
+static bool needs_mi_store_dword(struct drm_i915_private *i915)
+{
+ return igt_can_mi_store_dword_imm(i915);
+}
+
+static const struct igt_coherency_mode {
+ const char *name;
+ int (*set)(struct drm_i915_gem_object *, unsigned long offset, u32 v);
+ int (*get)(struct drm_i915_gem_object *, unsigned long offset, u32 *v);
+ bool (*valid)(struct drm_i915_private *i915);
+} igt_coherency_mode[] = {
+ { "cpu", cpu_set, cpu_get, always_valid },
+ { "gtt", gtt_set, gtt_get, always_valid },
+ { "wc", wc_set, wc_get, always_valid },
+ { "gpu", gpu_set, NULL, needs_mi_store_dword },
+ { },
+};
+
+static int igt_gem_coherency(void *arg)
+{
+ const unsigned int ncachelines = PAGE_SIZE/64;
+ I915_RND_STATE(prng);
+ struct drm_i915_private *i915 = arg;
+ const struct igt_coherency_mode *read, *write, *over;
+ struct drm_i915_gem_object *obj;
+ unsigned long count, n;
+ u32 *offsets, *values;
+ int err;
+
+ /* We repeatedly write, overwrite and read from a sequence of
+ * cachelines in order to try and detect incoherency (unflushed writes
+ * from either the CPU or GPU). Each setter/getter uses our cache
+ * domain API which should prevent incoherency.
+ */
+
+ offsets = kmalloc_array(ncachelines, 2*sizeof(u32), GFP_KERNEL);
+ if (!offsets)
+ return -ENOMEM;
+ for (count = 0; count < ncachelines; count++)
+ offsets[count] = count * 64 + 4 * (count % 16);
+
+ values = offsets + ncachelines;
+
+ mutex_lock(&i915->drm.struct_mutex);
+ for (over = igt_coherency_mode; over->name; over++) {
+ if (!over->set)
+ continue;
+
+ if (!over->valid(i915))
+ continue;
+
+ for (write = igt_coherency_mode; write->name; write++) {
+ if (!write->set)
+ continue;
+
+ if (!write->valid(i915))
+ continue;
+
+ for (read = igt_coherency_mode; read->name; read++) {
+ if (!read->get)
+ continue;
+
+ if (!read->valid(i915))
+ continue;
+
+ for_each_prime_number_from(count, 1, ncachelines) {
+ obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
+ if (IS_ERR(obj)) {
+ err = PTR_ERR(obj);
+ goto unlock;
+ }
+
+ i915_random_reorder(offsets, ncachelines, &prng);
+ for (n = 0; n < count; n++)
+ values[n] = prandom_u32_state(&prng);
+
+ for (n = 0; n < count; n++) {
+ err = over->set(obj, offsets[n], ~values[n]);
+ if (err) {
+ pr_err("Failed to set stale value[%ld/%ld] in object using %s, err=%d\n",
+ n, count, over->name, err);
+ goto put_object;
+ }
+ }
+
+ for (n = 0; n < count; n++) {
+ err = write->set(obj, offsets[n], values[n]);
+ if (err) {
+ pr_err("Failed to set value[%ld/%ld] in object using %s, err=%d\n",
+ n, count, write->name, err);
+ goto put_object;
+ }
+ }
+
+ for (n = 0; n < count; n++) {
+ u32 found;
+
+ err = read->get(obj, offsets[n], &found);
+ if (err) {
+ pr_err("Failed to get value[%ld/%ld] in object using %s, err=%d\n",
+ n, count, read->name, err);
+ goto put_object;
+ }
+
+ if (found != values[n]) {
+ pr_err("Value[%ld/%ld] mismatch, (overwrite with %s) wrote [%s] %x read [%s] %x (inverse %x), at offset %x\n",
+ n, count, over->name,
+ write->name, values[n],
+ read->name, found,
+ ~values[n], offsets[n]);
+ err = -EINVAL;
+ goto put_object;
+ }
+ }
+
+ __i915_gem_object_release_unless_active(obj);
+ }
+ }
+ }
+ }
+unlock:
+ mutex_unlock(&i915->drm.struct_mutex);
+ kfree(offsets);
+ return err;
+
+put_object:
+ __i915_gem_object_release_unless_active(obj);
+ goto unlock;
+}
+
+int i915_gem_coherency_live_selftests(struct drm_i915_private *i915)
+{
+ static const struct i915_subtest tests[] = {
+ SUBTEST(igt_gem_coherency),
+ };
+
+ return i915_subtests(tests, i915);
+}
diff --git a/drivers/gpu/drm/i915/selftests/i915_live_selftests.h b/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
index d720b03e2c01..8f0c207dbe22 100644
--- a/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
+++ b/drivers/gpu/drm/i915/selftests/i915_live_selftests.h
@@ -11,3 +11,4 @@
selftest(sanitycheck, i915_live_sanitycheck) /* keep first (igt selfcheck) */
selftest(requests, i915_gem_request_live_selftests)
selftest(objects, i915_gem_object_live_selftests)
+selftest(coherency, i915_gem_coherency_live_selftests)
--
2.11.0
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