[Intel-gfx] [RFC PATCH 111/162] drm/i915/lmem: support optional CPU clearing for special internal use
Matthew Auld
matthew.auld at intel.com
Fri Nov 27 12:06:27 UTC 2020
For some internal device local-memory objects it would be useful to have
an option to CPU clear the pages upon gathering the backing store. Note
that this might be before the blitter is useable, which is the case for
some internal GuC objects.
Signed-off-by: Matthew Auld <matthew.auld at intel.com>
---
.../gpu/drm/i915/gem/i915_gem_object_types.h | 6 +-
drivers/gpu/drm/i915/gem/i915_gem_region.c | 20 +++++
.../drm/i915/selftests/intel_memory_region.c | 90 ++++++++++++++++++-
3 files changed, 113 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index 115ad32c303f..8d639509b78b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -166,10 +166,12 @@ struct drm_i915_gem_object {
#define I915_BO_ALLOC_CONTIGUOUS BIT(0)
#define I915_BO_ALLOC_VOLATILE BIT(1)
#define I915_BO_ALLOC_STRUCT_PAGE BIT(2)
+#define I915_BO_ALLOC_CPU_CLEAR BIT(3)
#define I915_BO_ALLOC_FLAGS (I915_BO_ALLOC_CONTIGUOUS | \
I915_BO_ALLOC_VOLATILE | \
- I915_BO_ALLOC_STRUCT_PAGE)
-#define I915_BO_READONLY BIT(3)
+ I915_BO_ALLOC_STRUCT_PAGE | \
+ I915_BO_ALLOC_CPU_CLEAR)
+#define I915_BO_READONLY BIT(4)
/*
* Is the object to be mapped as read-only to the GPU
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.c b/drivers/gpu/drm/i915/gem/i915_gem_region.c
index 8f352ba6202d..e497ff374b13 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_region.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_region.c
@@ -95,6 +95,26 @@ i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj)
sg_mark_end(sg);
i915_sg_trim(st);
+ /* Intended for kernel internal use only */
+ if (obj->flags & I915_BO_ALLOC_CPU_CLEAR) {
+ struct scatterlist *sg;
+ unsigned long i;
+
+ for_each_sg(st->sgl, sg, st->nents, i) {
+ unsigned int length;
+ void __iomem *vaddr;
+ dma_addr_t daddr;
+
+ daddr = sg_dma_address(sg);
+ daddr -= mem->region.start;
+ length = sg_dma_len(sg);
+
+ vaddr = io_mapping_map_wc(&mem->iomap, daddr, length);
+ memset64(vaddr, 0, length / sizeof(u64));
+ io_mapping_unmap(vaddr);
+ }
+ }
+
__i915_gem_object_set_pages(obj, st, sg_page_sizes);
return 0;
diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
index 7acb94e0e5fe..93e067951e0f 100644
--- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
@@ -361,7 +361,7 @@ static int igt_cpu_check(struct drm_i915_gem_object *obj, u32 dword, u32 val)
if (err)
return err;
- ptr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WC);
+ ptr = i915_gem_object_pin_map(obj, I915_MAP_WC);
if (IS_ERR(ptr))
return PTR_ERR(ptr);
@@ -441,7 +441,9 @@ static int igt_gpu_write(struct i915_gem_context *ctx,
if (err)
break;
+ i915_gem_object_lock(obj, NULL);
err = igt_cpu_check(obj, dword, rng);
+ i915_gem_object_unlock(obj);
if (err)
break;
} while (!__igt_timeout(end_time, NULL));
@@ -542,6 +544,91 @@ static int igt_lmem_create_migrate(void *arg)
return err;
}
+
+static int igt_lmem_create_cleared_cpu(void *arg)
+{
+ struct drm_i915_private *i915 = arg;
+ I915_RND_STATE(prng);
+ IGT_TIMEOUT(end_time);
+ u32 size, val, i;
+ int err;
+
+ i915_gem_drain_freed_objects(i915);
+
+ size = max_t(u32, PAGE_SIZE, i915_prandom_u32_max_state(SZ_32M, &prng));
+ size = round_up(size, PAGE_SIZE);
+ i = 0;
+
+ do {
+ struct drm_i915_gem_object *obj;
+ void __iomem *vaddr;
+ unsigned int flags;
+ unsigned long n;
+ u32 dword;
+
+ /*
+ * Alternate between cleared and uncleared allocations, while
+ * also dirtying the pages each time to check that they either
+ * remain dirty or are indeed cleared. Allocations should be
+ * deterministic.
+ */
+
+ flags = I915_BO_ALLOC_CPU_CLEAR;
+ if (i & 1)
+ flags = 0;
+ else
+ val = 0;
+
+ obj = i915_gem_object_create_lmem(i915, size, flags);
+ if (IS_ERR(obj))
+ return PTR_ERR(obj);
+
+ i915_gem_object_lock(obj, NULL);
+ err = i915_gem_object_pin_pages(obj);
+ if (err)
+ goto out_put;
+
+ dword = i915_prandom_u32_max_state(PAGE_SIZE / sizeof(u32),
+ &prng);
+
+ err = igt_cpu_check(obj, dword, val);
+ if (err) {
+ pr_err("%s failed with size=%u, flags=%u\n",
+ __func__, size, flags);
+ goto out_unpin;
+ }
+
+ vaddr = i915_gem_object_pin_map(obj, I915_MAP_WC);
+ if (IS_ERR(vaddr)) {
+ err = PTR_ERR(vaddr);
+ goto out_unpin;
+ }
+
+ val = prandom_u32_state(&prng);
+
+ for (n = 0; n < obj->base.size >> PAGE_SHIFT; ++n) {
+ memset32(vaddr + n * PAGE_SIZE, val,
+ PAGE_SIZE / sizeof(u32));
+ }
+
+ i915_gem_object_unpin_map(obj);
+out_unpin:
+ i915_gem_object_unpin_pages(obj);
+ __i915_gem_object_put_pages(obj);
+out_put:
+ i915_gem_object_unlock(obj);
+ i915_gem_object_put(obj);
+
+ if (err)
+ break;
+ ++i;
+ } while (!__igt_timeout(end_time, NULL));
+
+ pr_info("%s completed (%u) iterations\n", __func__, i);
+
+ return err;
+}
+
static int igt_lmem_write_gpu(void *arg)
{
struct drm_i915_private *i915 = arg;
@@ -1125,6 +1212,7 @@ int intel_memory_region_live_selftests(struct drm_i915_private *i915)
{
static const struct i915_subtest tests[] = {
SUBTEST(igt_lmem_create),
+ SUBTEST(igt_lmem_create_cleared_cpu),
SUBTEST(igt_lmem_write_cpu),
SUBTEST(igt_lmem_write_gpu),
SUBTEST(igt_smem_create_migrate),
--
2.26.2
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