[Intel-gfx] [PATCH v2 1/4] drm/i915: enforce min GTT alignment for discrete cards
Robert Beckett
bob.beckett at collabora.com
Thu Jan 20 13:15:15 UTC 2022
On 20/01/2022 11:46, Ramalingam C wrote:
> On 2022-01-18 at 17:50:34 +0000, Robert Beckett wrote:
>> From: Matthew Auld <matthew.auld at intel.com>
>>
>> For local-memory objects we need to align the GTT addresses
>> to 64K, both for the ppgtt and ggtt.
>>
>> We need to support vm->min_alignment > 4K, depending
>> on the vm itself and the type of object we are inserting.
>> With this in mind update the GTT selftests to take this
>> into account.
>>
>> For DG2 we further align and pad lmem object GTT addresses
>> to 2MB to ensure PDEs contain consistent page sizes as
>> required by the HW.
>>
>> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
>> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>> Signed-off-by: Robert Beckett <bob.beckett at collabora.com>
>> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
>> ---
>> .../i915/gem/selftests/i915_gem_client_blt.c | 23 +++--
>> drivers/gpu/drm/i915/gt/intel_gtt.c | 14 +++
>> drivers/gpu/drm/i915/gt/intel_gtt.h | 9 ++
>> drivers/gpu/drm/i915/i915_vma.c | 14 +++
>> drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 96 ++++++++++++-------
>> 5 files changed, 115 insertions(+), 41 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_client_blt.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_client_blt.c
>> index c08f766e6e15..7fee95a65414 100644
>> --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_client_blt.c
>> +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_client_blt.c
>> @@ -39,6 +39,7 @@ struct tiled_blits {
>> struct blit_buffer scratch;
>> struct i915_vma *batch;
>> u64 hole;
>> + u64 align;
>> u32 width;
>> u32 height;
>> };
>> @@ -410,14 +411,21 @@ tiled_blits_create(struct intel_engine_cs *engine, struct rnd_state *prng)
>> goto err_free;
>> }
>>
>> - hole_size = 2 * PAGE_ALIGN(WIDTH * HEIGHT * 4);
>> + t->align = I915_GTT_PAGE_SIZE_2M; /* XXX worst case, derive from vm! */
>> + t->align = max(t->align,
>> + i915_vm_min_alignment(t->ce->vm, INTEL_MEMORY_LOCAL));
>> + t->align = max(t->align,
>> + i915_vm_min_alignment(t->ce->vm, INTEL_MEMORY_SYSTEM));
>> +
>> + hole_size = 2 * round_up(WIDTH * HEIGHT * 4, t->align);
>> hole_size *= 2; /* room to maneuver */
>> - hole_size += 2 * I915_GTT_MIN_ALIGNMENT;
>> + hole_size += 2 * t->align; /* padding on either side */
>>
>> mutex_lock(&t->ce->vm->mutex);
>> memset(&hole, 0, sizeof(hole));
>> err = drm_mm_insert_node_in_range(&t->ce->vm->mm, &hole,
>> - hole_size, 0, I915_COLOR_UNEVICTABLE,
>> + hole_size, t->align,
>> + I915_COLOR_UNEVICTABLE,
>> 0, U64_MAX,
>> DRM_MM_INSERT_BEST);
>> if (!err)
>> @@ -428,7 +436,7 @@ tiled_blits_create(struct intel_engine_cs *engine, struct rnd_state *prng)
>> goto err_put;
>> }
>>
>> - t->hole = hole.start + I915_GTT_MIN_ALIGNMENT;
>> + t->hole = hole.start + t->align;
>> pr_info("Using hole at %llx\n", t->hole);
>>
>> err = tiled_blits_create_buffers(t, WIDTH, HEIGHT, prng);
>> @@ -455,7 +463,7 @@ static void tiled_blits_destroy(struct tiled_blits *t)
>> static int tiled_blits_prepare(struct tiled_blits *t,
>> struct rnd_state *prng)
>> {
>> - u64 offset = PAGE_ALIGN(t->width * t->height * 4);
>> + u64 offset = round_up(t->width * t->height * 4, t->align);
>> u32 *map;
>> int err;
>> int i;
>> @@ -486,8 +494,7 @@ static int tiled_blits_prepare(struct tiled_blits *t,
>>
>> static int tiled_blits_bounce(struct tiled_blits *t, struct rnd_state *prng)
>> {
>> - u64 offset =
>> - round_up(t->width * t->height * 4, 2 * I915_GTT_MIN_ALIGNMENT);
>> + u64 offset = round_up(t->width * t->height * 4, 2 * t->align);
>> int err;
>>
>> /* We want to check position invariant tiling across GTT eviction */
>> @@ -500,7 +507,7 @@ static int tiled_blits_bounce(struct tiled_blits *t, struct rnd_state *prng)
>>
>> /* Reposition so that we overlap the old addresses, and slightly off */
>> err = tiled_blit(t,
>> - &t->buffers[2], t->hole + I915_GTT_MIN_ALIGNMENT,
>> + &t->buffers[2], t->hole + t->align,
>> &t->buffers[1], t->hole + 3 * offset / 2);
>> if (err)
>> return err;
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
>> index 46be4197b93f..7c92b25c0f26 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gtt.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
>> @@ -223,6 +223,20 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
>>
>> GEM_BUG_ON(!vm->total);
>> drm_mm_init(&vm->mm, 0, vm->total);
>> +
>> + memset64(vm->min_alignment, I915_GTT_MIN_ALIGNMENT,
>> + ARRAY_SIZE(vm->min_alignment));
>> +
>> + if (HAS_64K_PAGES(vm->i915)) {
>> + if (IS_DG2(vm->i915)) {
> I think we need this 2M alignment for all platform with HAS_64K_PAGES.
> Not only for DG2.
really? can we get confirmation of this?
this contradicts the documentation in patch 4, which you reviewed, so I
am confused now
>> + vm->min_alignment[INTEL_MEMORY_LOCAL] = I915_GTT_PAGE_SIZE_2M;
>> + vm->min_alignment[INTEL_MEMORY_STOLEN_LOCAL] = I915_GTT_PAGE_SIZE_2M;
>> + } else {
>> + vm->min_alignment[INTEL_MEMORY_LOCAL] = I915_GTT_PAGE_SIZE_64K;
>> + vm->min_alignment[INTEL_MEMORY_STOLEN_LOCAL] = I915_GTT_PAGE_SIZE_64K;
>> + }
>> + }
>> +
>> vm->mm.head_node.color = I915_COLOR_UNEVICTABLE;
>>
>> INIT_LIST_HEAD(&vm->bound_list);
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
>> index 8073438b67c8..b8da2514d601 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
>> @@ -29,6 +29,8 @@
>> #include "i915_selftest.h"
>> #include "i915_vma_resource.h"
>> #include "i915_vma_types.h"
>> +#include "i915_params.h"
>> +#include "intel_memory_region.h"
>>
>> #define I915_GFP_ALLOW_FAIL (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN)
>>
>> @@ -223,6 +225,7 @@ struct i915_address_space {
>> struct device *dma;
>> u64 total; /* size addr space maps (ex. 2GB for ggtt) */
>> u64 reserved; /* size addr space reserved */
>> + u64 min_alignment[INTEL_MEMORY_STOLEN_LOCAL + 1];
>>
>> unsigned int bind_async_flags;
>>
>> @@ -384,6 +387,12 @@ i915_vm_has_scratch_64K(struct i915_address_space *vm)
>> return vm->scratch_order == get_order(I915_GTT_PAGE_SIZE_64K);
>> }
>>
>> +static inline u64 i915_vm_min_alignment(struct i915_address_space *vm,
>> + enum intel_memory_type type)
>> +{
>> + return vm->min_alignment[type];
>> +}
>> +
>> static inline bool
>> i915_vm_has_cache_coloring(struct i915_address_space *vm)
>> {
>> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
>> index 1f15c3298112..9ac92e7a3566 100644
>> --- a/drivers/gpu/drm/i915/i915_vma.c
>> +++ b/drivers/gpu/drm/i915/i915_vma.c
>> @@ -756,6 +756,20 @@ i915_vma_insert(struct i915_vma *vma, u64 size, u64 alignment, u64 flags)
>> }
>>
>> color = 0;
>> +
>> + if (HAS_64K_PAGES(vma->vm->i915) && i915_gem_object_is_lmem(vma->obj)) {
>> + alignment = max(alignment, I915_GTT_PAGE_SIZE_64K);
>> + /*
>> + * DG2 can not have different sized pages in any given PDE (2MB range).
>> + * Keeping things simple, we force any lmem object to reserve
>> + * 2MB chunks, preventing any smaller pages being used alongside
>> + */
>> + if (IS_DG2(vma->vm->i915)) {
> Similarly here we dont need special case for DG2.
>
> Ram
>> + alignment = max(alignment, I915_GTT_PAGE_SIZE_2M);
>> + size = round_up(size, I915_GTT_PAGE_SIZE_2M);
>> + }
>> + }
>> +
>> if (i915_vm_has_cache_coloring(vma->vm))
>> color = vma->obj->cache_level;
>>
>> diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
>> index 076d860ce01a..2f3f0c01786b 100644
>> --- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
>> +++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
>> @@ -238,6 +238,8 @@ static int lowlevel_hole(struct i915_address_space *vm,
>> u64 hole_start, u64 hole_end,
>> unsigned long end_time)
>> {
>> + const unsigned int min_alignment =
>> + i915_vm_min_alignment(vm, INTEL_MEMORY_SYSTEM);
>> I915_RND_STATE(seed_prng);
>> struct i915_vma_resource *mock_vma_res;
>> unsigned int size;
>> @@ -251,9 +253,10 @@ static int lowlevel_hole(struct i915_address_space *vm,
>> I915_RND_SUBSTATE(prng, seed_prng);
>> struct drm_i915_gem_object *obj;
>> unsigned int *order, count, n;
>> - u64 hole_size;
>> + u64 hole_size, aligned_size;
>>
>> - hole_size = (hole_end - hole_start) >> size;
>> + aligned_size = max_t(u32, ilog2(min_alignment), size);
>> + hole_size = (hole_end - hole_start) >> aligned_size;
>> if (hole_size > KMALLOC_MAX_SIZE / sizeof(u32))
>> hole_size = KMALLOC_MAX_SIZE / sizeof(u32);
>> count = hole_size >> 1;
>> @@ -274,8 +277,8 @@ static int lowlevel_hole(struct i915_address_space *vm,
>> }
>> GEM_BUG_ON(!order);
>>
>> - GEM_BUG_ON(count * BIT_ULL(size) > vm->total);
>> - GEM_BUG_ON(hole_start + count * BIT_ULL(size) > hole_end);
>> + GEM_BUG_ON(count * BIT_ULL(aligned_size) > vm->total);
>> + GEM_BUG_ON(hole_start + count * BIT_ULL(aligned_size) > hole_end);
>>
>> /* Ignore allocation failures (i.e. don't report them as
>> * a test failure) as we are purposefully allocating very
>> @@ -298,10 +301,10 @@ static int lowlevel_hole(struct i915_address_space *vm,
>> }
>>
>> for (n = 0; n < count; n++) {
>> - u64 addr = hole_start + order[n] * BIT_ULL(size);
>> + u64 addr = hole_start + order[n] * BIT_ULL(aligned_size);
>> intel_wakeref_t wakeref;
>>
>> - GEM_BUG_ON(addr + BIT_ULL(size) > vm->total);
>> + GEM_BUG_ON(addr + BIT_ULL(aligned_size) > vm->total);
>>
>> if (igt_timeout(end_time,
>> "%s timed out before %d/%d\n",
>> @@ -344,7 +347,7 @@ static int lowlevel_hole(struct i915_address_space *vm,
>> }
>>
>> mock_vma_res->bi.pages = obj->mm.pages;
>> - mock_vma_res->node_size = BIT_ULL(size);
>> + mock_vma_res->node_size = BIT_ULL(aligned_size);
>> mock_vma_res->start = addr;
>>
>> with_intel_runtime_pm(vm->gt->uncore->rpm, wakeref)
>> @@ -355,7 +358,7 @@ static int lowlevel_hole(struct i915_address_space *vm,
>>
>> i915_random_reorder(order, count, &prng);
>> for (n = 0; n < count; n++) {
>> - u64 addr = hole_start + order[n] * BIT_ULL(size);
>> + u64 addr = hole_start + order[n] * BIT_ULL(aligned_size);
>> intel_wakeref_t wakeref;
>>
>> GEM_BUG_ON(addr + BIT_ULL(size) > vm->total);
>> @@ -399,8 +402,10 @@ static int fill_hole(struct i915_address_space *vm,
>> {
>> const u64 hole_size = hole_end - hole_start;
>> struct drm_i915_gem_object *obj;
>> + const unsigned int min_alignment =
>> + i915_vm_min_alignment(vm, INTEL_MEMORY_SYSTEM);
>> const unsigned long max_pages =
>> - min_t(u64, ULONG_MAX - 1, hole_size/2 >> PAGE_SHIFT);
>> + min_t(u64, ULONG_MAX - 1, (hole_size / 2) >> ilog2(min_alignment));
>> const unsigned long max_step = max(int_sqrt(max_pages), 2UL);
>> unsigned long npages, prime, flags;
>> struct i915_vma *vma;
>> @@ -441,14 +446,17 @@ static int fill_hole(struct i915_address_space *vm,
>>
>> offset = p->offset;
>> list_for_each_entry(obj, &objects, st_link) {
>> + u64 aligned_size = round_up(obj->base.size,
>> + min_alignment);
>> +
>> vma = i915_vma_instance(obj, vm, NULL);
>> if (IS_ERR(vma))
>> continue;
>>
>> if (p->step < 0) {
>> - if (offset < hole_start + obj->base.size)
>> + if (offset < hole_start + aligned_size)
>> break;
>> - offset -= obj->base.size;
>> + offset -= aligned_size;
>> }
>>
>> err = i915_vma_pin(vma, 0, 0, offset | flags);
>> @@ -470,22 +478,25 @@ static int fill_hole(struct i915_address_space *vm,
>> i915_vma_unpin(vma);
>>
>> if (p->step > 0) {
>> - if (offset + obj->base.size > hole_end)
>> + if (offset + aligned_size > hole_end)
>> break;
>> - offset += obj->base.size;
>> + offset += aligned_size;
>> }
>> }
>>
>> offset = p->offset;
>> list_for_each_entry(obj, &objects, st_link) {
>> + u64 aligned_size = round_up(obj->base.size,
>> + min_alignment);
>> +
>> vma = i915_vma_instance(obj, vm, NULL);
>> if (IS_ERR(vma))
>> continue;
>>
>> if (p->step < 0) {
>> - if (offset < hole_start + obj->base.size)
>> + if (offset < hole_start + aligned_size)
>> break;
>> - offset -= obj->base.size;
>> + offset -= aligned_size;
>> }
>>
>> if (!drm_mm_node_allocated(&vma->node) ||
>> @@ -506,22 +517,25 @@ static int fill_hole(struct i915_address_space *vm,
>> }
>>
>> if (p->step > 0) {
>> - if (offset + obj->base.size > hole_end)
>> + if (offset + aligned_size > hole_end)
>> break;
>> - offset += obj->base.size;
>> + offset += aligned_size;
>> }
>> }
>>
>> offset = p->offset;
>> list_for_each_entry_reverse(obj, &objects, st_link) {
>> + u64 aligned_size = round_up(obj->base.size,
>> + min_alignment);
>> +
>> vma = i915_vma_instance(obj, vm, NULL);
>> if (IS_ERR(vma))
>> continue;
>>
>> if (p->step < 0) {
>> - if (offset < hole_start + obj->base.size)
>> + if (offset < hole_start + aligned_size)
>> break;
>> - offset -= obj->base.size;
>> + offset -= aligned_size;
>> }
>>
>> err = i915_vma_pin(vma, 0, 0, offset | flags);
>> @@ -543,22 +557,25 @@ static int fill_hole(struct i915_address_space *vm,
>> i915_vma_unpin(vma);
>>
>> if (p->step > 0) {
>> - if (offset + obj->base.size > hole_end)
>> + if (offset + aligned_size > hole_end)
>> break;
>> - offset += obj->base.size;
>> + offset += aligned_size;
>> }
>> }
>>
>> offset = p->offset;
>> list_for_each_entry_reverse(obj, &objects, st_link) {
>> + u64 aligned_size = round_up(obj->base.size,
>> + min_alignment);
>> +
>> vma = i915_vma_instance(obj, vm, NULL);
>> if (IS_ERR(vma))
>> continue;
>>
>> if (p->step < 0) {
>> - if (offset < hole_start + obj->base.size)
>> + if (offset < hole_start + aligned_size)
>> break;
>> - offset -= obj->base.size;
>> + offset -= aligned_size;
>> }
>>
>> if (!drm_mm_node_allocated(&vma->node) ||
>> @@ -579,9 +596,9 @@ static int fill_hole(struct i915_address_space *vm,
>> }
>>
>> if (p->step > 0) {
>> - if (offset + obj->base.size > hole_end)
>> + if (offset + aligned_size > hole_end)
>> break;
>> - offset += obj->base.size;
>> + offset += aligned_size;
>> }
>> }
>> }
>> @@ -611,6 +628,7 @@ static int walk_hole(struct i915_address_space *vm,
>> const u64 hole_size = hole_end - hole_start;
>> const unsigned long max_pages =
>> min_t(u64, ULONG_MAX - 1, hole_size >> PAGE_SHIFT);
>> + unsigned long min_alignment;
>> unsigned long flags;
>> u64 size;
>>
>> @@ -620,6 +638,8 @@ static int walk_hole(struct i915_address_space *vm,
>> if (i915_is_ggtt(vm))
>> flags |= PIN_GLOBAL;
>>
>> + min_alignment = i915_vm_min_alignment(vm, INTEL_MEMORY_SYSTEM);
>> +
>> for_each_prime_number_from(size, 1, max_pages) {
>> struct drm_i915_gem_object *obj;
>> struct i915_vma *vma;
>> @@ -638,7 +658,7 @@ static int walk_hole(struct i915_address_space *vm,
>>
>> for (addr = hole_start;
>> addr + obj->base.size < hole_end;
>> - addr += obj->base.size) {
>> + addr += round_up(obj->base.size, min_alignment)) {
>> err = i915_vma_pin(vma, 0, 0, addr | flags);
>> if (err) {
>> pr_err("%s bind failed at %llx + %llx [hole %llx- %llx] with err=%d\n",
>> @@ -690,6 +710,7 @@ static int pot_hole(struct i915_address_space *vm,
>> {
>> struct drm_i915_gem_object *obj;
>> struct i915_vma *vma;
>> + unsigned int min_alignment;
>> unsigned long flags;
>> unsigned int pot;
>> int err = 0;
>> @@ -698,6 +719,8 @@ static int pot_hole(struct i915_address_space *vm,
>> if (i915_is_ggtt(vm))
>> flags |= PIN_GLOBAL;
>>
>> + min_alignment = i915_vm_min_alignment(vm, INTEL_MEMORY_SYSTEM);
>> +
>> obj = i915_gem_object_create_internal(vm->i915, 2 * I915_GTT_PAGE_SIZE);
>> if (IS_ERR(obj))
>> return PTR_ERR(obj);
>> @@ -710,13 +733,13 @@ static int pot_hole(struct i915_address_space *vm,
>>
>> /* Insert a pair of pages across every pot boundary within the hole */
>> for (pot = fls64(hole_end - 1) - 1;
>> - pot > ilog2(2 * I915_GTT_PAGE_SIZE);
>> + pot > ilog2(2 * min_alignment);
>> pot--) {
>> u64 step = BIT_ULL(pot);
>> u64 addr;
>>
>> - for (addr = round_up(hole_start + I915_GTT_PAGE_SIZE, step) - I915_GTT_PAGE_SIZE;
>> - addr <= round_down(hole_end - 2*I915_GTT_PAGE_SIZE, step) - I915_GTT_PAGE_SIZE;
>> + for (addr = round_up(hole_start + min_alignment, step) - min_alignment;
>> + addr <= round_down(hole_end - (2 * min_alignment), step) - min_alignment;
>> addr += step) {
>> err = i915_vma_pin(vma, 0, 0, addr | flags);
>> if (err) {
>> @@ -761,6 +784,7 @@ static int drunk_hole(struct i915_address_space *vm,
>> unsigned long end_time)
>> {
>> I915_RND_STATE(prng);
>> + unsigned int min_alignment;
>> unsigned int size;
>> unsigned long flags;
>>
>> @@ -768,15 +792,18 @@ static int drunk_hole(struct i915_address_space *vm,
>> if (i915_is_ggtt(vm))
>> flags |= PIN_GLOBAL;
>>
>> + min_alignment = i915_vm_min_alignment(vm, INTEL_MEMORY_SYSTEM);
>> +
>> /* Keep creating larger objects until one cannot fit into the hole */
>> for (size = 12; (hole_end - hole_start) >> size; size++) {
>> struct drm_i915_gem_object *obj;
>> unsigned int *order, count, n;
>> struct i915_vma *vma;
>> - u64 hole_size;
>> + u64 hole_size, aligned_size;
>> int err = -ENODEV;
>>
>> - hole_size = (hole_end - hole_start) >> size;
>> + aligned_size = max_t(u32, ilog2(min_alignment), size);
>> + hole_size = (hole_end - hole_start) >> aligned_size;
>> if (hole_size > KMALLOC_MAX_SIZE / sizeof(u32))
>> hole_size = KMALLOC_MAX_SIZE / sizeof(u32);
>> count = hole_size >> 1;
>> @@ -816,7 +843,7 @@ static int drunk_hole(struct i915_address_space *vm,
>> GEM_BUG_ON(vma->size != BIT_ULL(size));
>>
>> for (n = 0; n < count; n++) {
>> - u64 addr = hole_start + order[n] * BIT_ULL(size);
>> + u64 addr = hole_start + order[n] * BIT_ULL(aligned_size);
>>
>> err = i915_vma_pin(vma, 0, 0, addr | flags);
>> if (err) {
>> @@ -868,11 +895,14 @@ static int __shrink_hole(struct i915_address_space *vm,
>> {
>> struct drm_i915_gem_object *obj;
>> unsigned long flags = PIN_OFFSET_FIXED | PIN_USER;
>> + unsigned int min_alignment;
>> unsigned int order = 12;
>> LIST_HEAD(objects);
>> int err = 0;
>> u64 addr;
>>
>> + min_alignment = i915_vm_min_alignment(vm, INTEL_MEMORY_SYSTEM);
>> +
>> /* Keep creating larger objects until one cannot fit into the hole */
>> for (addr = hole_start; addr < hole_end; ) {
>> struct i915_vma *vma;
>> @@ -913,7 +943,7 @@ static int __shrink_hole(struct i915_address_space *vm,
>> }
>>
>> i915_vma_unpin(vma);
>> - addr += size;
>> + addr += round_up(size, min_alignment);
>>
>> /*
>> * Since we are injecting allocation faults at random intervals,
>> --
>> 2.25.1
>>
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