[Intel-gfx] [PATCH 3/3] drm/i915/blt: bump the size restriction

Chris Wilson chris at chris-wilson.co.uk
Fri Aug 9 21:18:06 UTC 2019


Quoting Matthew Auld (2019-08-09 21:29:26)
> As pointed out by Chris, with our current approach we are actually
> limited to S16_MAX * PAGE_SIZE for our size when using the blt to clear
> pages. Keeping things simple try to fix this by reducing the copy to a
> sequence of S16_MAX * PAGE_SIZE blocks.
> 
> Reported-by: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  .../gpu/drm/i915/gem/i915_gem_client_blt.c    |  31 +++-
>  .../gpu/drm/i915/gem/i915_gem_object_blt.c    | 139 ++++++++++++++----
>  .../gpu/drm/i915/gem/i915_gem_object_blt.h    |   9 +-
>  .../i915/gem/selftests/i915_gem_client_blt.c  |  16 +-
>  .../i915/gem/selftests/i915_gem_object_blt.c  |  22 ++-
>  5 files changed, 170 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_client_blt.c b/drivers/gpu/drm/i915/gem/i915_gem_client_blt.c
> index 08a84c940d8d..4b096309a97e 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_client_blt.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_client_blt.c
> @@ -5,6 +5,8 @@
>  
>  #include "i915_drv.h"
>  #include "gt/intel_context.h"
> +#include "gt/intel_engine_pm.h"
> +#include "gt/intel_engine_pool.h"
>  #include "i915_gem_client_blt.h"
>  #include "i915_gem_object_blt.h"
>  
> @@ -156,7 +158,9 @@ static void clear_pages_worker(struct work_struct *work)
>         struct drm_i915_private *i915 = w->ce->engine->i915;
>         struct drm_i915_gem_object *obj = w->sleeve->vma->obj;
>         struct i915_vma *vma = w->sleeve->vma;
> +       struct intel_engine_pool_node *pool;
>         struct i915_request *rq;
> +       struct i915_vma *batch;
>         int err = w->dma.error;
>  
>         if (unlikely(err))
> @@ -176,10 +180,17 @@ static void clear_pages_worker(struct work_struct *work)
>         if (unlikely(err))
>                 goto out_unlock;
>  
> +       intel_engine_pm_get(w->ce->engine);
> +       batch = intel_emit_vma_fill_blt(&pool, w->ce, vma, w->value);

I had to search for where pool was being set!

Hmm, batch is from pool right? So we are the owner of the batch, and we
could set batch->private = pool.

> +       if (IS_ERR(batch)) {
> +               err = PTR_ERR(batch);
> +               goto out_unpin;
> +       }
> +
>         rq = intel_context_create_request(w->ce);
>         if (IS_ERR(rq)) {
>                 err = PTR_ERR(rq);
> -               goto out_unpin;
> +               goto out_batch;
>         }
>  
>         /* There's no way the fence has signalled */
> @@ -187,6 +198,16 @@ static void clear_pages_worker(struct work_struct *work)
>                                    clear_pages_dma_fence_cb))
>                 GEM_BUG_ON(1);
>  
> +       i915_vma_lock(batch);
> +       err = i915_vma_move_to_active(batch, rq, 0);
> +       i915_vma_unlock(batch);
> +       if (unlikely(err))
> +               goto out_request;
> +
> +       err = intel_engine_pool_mark_active(pool, rq);
> +       if (unlikely(err))
> +               goto out_request;
> +
>         if (w->ce->engine->emit_init_breadcrumb) {
>                 err = w->ce->engine->emit_init_breadcrumb(rq);
>                 if (unlikely(err))
> @@ -202,7 +223,9 @@ static void clear_pages_worker(struct work_struct *work)
>         if (err)
>                 goto out_request;
>  
> -       err = intel_emit_vma_fill_blt(rq, vma, w->value);
> +       err = w->ce->engine->emit_bb_start(rq,
> +                                          batch->node.start, batch->node.size,
> +                                          0);
>  out_request:
>         if (unlikely(err)) {
>                 i915_request_skip(rq, err);
> @@ -210,7 +233,11 @@ static void clear_pages_worker(struct work_struct *work)
>         }
>  
>         i915_request_add(rq);
> +out_batch:
> +       i915_vma_unpin(batch);
> +       intel_engine_pool_put(pool);
>  out_unpin:
> +       intel_engine_pm_put(w->ce->engine);
>         i915_vma_unpin(vma);
>  out_unlock:
>         mutex_unlock(&i915->drm.struct_mutex);
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_blt.c b/drivers/gpu/drm/i915/gem/i915_gem_object_blt.c
> index fa90c38c8b07..c1e5edd1e359 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_object_blt.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object_blt.c
> @@ -5,49 +5,103 @@
>  
>  #include "i915_drv.h"
>  #include "gt/intel_context.h"
> +#include "gt/intel_engine_pm.h"
> +#include "gt/intel_engine_pool.h"
> +#include "gt/intel_gt.h"
>  #include "i915_gem_clflush.h"
>  #include "i915_gem_object_blt.h"
>  
> -int intel_emit_vma_fill_blt(struct i915_request *rq,
> -                           struct i915_vma *vma,
> -                           u32 value)
> +struct i915_vma *intel_emit_vma_fill_blt(struct intel_engine_pool_node **p,
> +                                        struct intel_context *ce,
> +                                        struct i915_vma *vma,
> +                                        u32 value)
>  {
> -       u32 *cs;
> -
> -       cs = intel_ring_begin(rq, 8);
> -       if (IS_ERR(cs))
> -               return PTR_ERR(cs);
> -
> -       if (INTEL_GEN(rq->i915) >= 8) {
> -               *cs++ = XY_COLOR_BLT_CMD | BLT_WRITE_RGBA | (7 - 2);
> -               *cs++ = BLT_DEPTH_32 | BLT_ROP_COLOR_COPY | PAGE_SIZE;
> -               *cs++ = 0;
> -               *cs++ = vma->size >> PAGE_SHIFT << 16 | PAGE_SIZE / 4;
> -               *cs++ = lower_32_bits(vma->node.start);
> -               *cs++ = upper_32_bits(vma->node.start);
> -               *cs++ = value;
> -               *cs++ = MI_NOOP;
> -       } else {
> -               *cs++ = XY_COLOR_BLT_CMD | BLT_WRITE_RGBA | (6 - 2);
> -               *cs++ = BLT_DEPTH_32 | BLT_ROP_COLOR_COPY | PAGE_SIZE;
> -               *cs++ = 0;
> -               *cs++ = vma->size >> PAGE_SHIFT << 16 | PAGE_SIZE / 4;
> -               *cs++ = vma->node.start;
> -               *cs++ = value;
> -               *cs++ = MI_NOOP;
> -               *cs++ = MI_NOOP;
> +       struct drm_i915_private *i915 = ce->vm->i915;
> +       const u32 block_size = S16_MAX * PAGE_SIZE;
> +       struct intel_engine_pool_node *pool;
> +       struct i915_vma *batch;
> +       u64 offset;
> +       u64 count;
> +       u64 rem;
> +       u32 size;
> +       u32 *cmd;
> +       int err;
> +
> +       count = div_u64(vma->size, block_size);
> +       size = (1 + 8 * count) * sizeof(u32);
> +       size = round_up(size, PAGE_SIZE);
> +       pool = intel_engine_pool_get(&ce->engine->pool, size);
> +       if (IS_ERR(pool))
> +               return ERR_CAST(pool);
> +
> +       cmd = i915_gem_object_pin_map(pool->obj, I915_MAP_WC);
> +       if (IS_ERR(cmd)) {
> +               err = PTR_ERR(cmd);
> +               goto out_put;
> +       }
> +
> +       rem = vma->size;
> +       offset = vma->node.start;
> +
> +       do {
> +               u32 size = min_t(u64, rem, block_size);
> +
> +               GEM_BUG_ON(size >> PAGE_SHIFT > S16_MAX);
> +
> +               if (INTEL_GEN(i915) >= 8) {
> +                       *cmd++ = XY_COLOR_BLT_CMD | BLT_WRITE_RGBA | (7 - 2);
> +                       *cmd++ = BLT_DEPTH_32 | BLT_ROP_COLOR_COPY | PAGE_SIZE;
> +                       *cmd++ = 0;
> +                       *cmd++ = size >> PAGE_SHIFT << 16 | PAGE_SIZE / 4;
> +                       *cmd++ = lower_32_bits(offset);
> +                       *cmd++ = upper_32_bits(offset);
> +                       *cmd++ = value;
> +               } else {
> +                       *cmd++ = XY_COLOR_BLT_CMD | BLT_WRITE_RGBA | (6 - 2);
> +                       *cmd++ = BLT_DEPTH_32 | BLT_ROP_COLOR_COPY | PAGE_SIZE;
> +                       *cmd++ = 0;
> +                       *cmd++ = size >> PAGE_SHIFT << 16 | PAGE_SIZE / 4;
> +                       *cmd++ = offset;
> +                       *cmd++ = value;
> +               }
> +
> +               /* Allow ourselves to be preempted in between blocks. */
> +               *cmd++ = MI_ARB_CHECK;

That I thought was a nice touch.

> +
> +               offset += size;
> +               rem -= size;
> +       } while (rem);
> +
> +       *cmd = MI_BATCH_BUFFER_END;
> +       intel_gt_chipset_flush(ce->vm->gt);
> +
> +       i915_gem_object_unpin_map(pool->obj);
> +
> +       batch = i915_vma_instance(pool->obj, ce->vm, NULL);
> +       if (IS_ERR(batch)) {
> +               err = PTR_ERR(batch);
> +               goto out_put;
>         }
>  
> -       intel_ring_advance(rq, cs);
> +       err = i915_vma_pin(batch, 0, 0, PIN_USER);
> +       if (unlikely(err))
> +               goto out_put;
> +
> +       *p = pool;
> +       return batch;
>  
> -       return 0;
> +out_put:
> +       intel_engine_pool_put(pool);
> +       return ERR_PTR(err);
>  }
>  
>  int i915_gem_object_fill_blt(struct drm_i915_gem_object *obj,
>                              struct intel_context *ce,
>                              u32 value)
>  {
> +       struct intel_engine_pool_node *pool;
>         struct i915_request *rq;
> +       struct i915_vma *batch;
>         struct i915_vma *vma;
>         int err;
>  
> @@ -65,12 +119,29 @@ int i915_gem_object_fill_blt(struct drm_i915_gem_object *obj,
>                 i915_gem_object_unlock(obj);
>         }
>  
> +       intel_engine_pm_get(ce->engine);
> +       batch = intel_emit_vma_fill_blt(&pool, ce, vma, value);
> +       if (IS_ERR(batch)) {
> +               err = PTR_ERR(batch);
> +               goto out_unpin;
> +       }
> +
>         rq = intel_context_create_request(ce);
>         if (IS_ERR(rq)) {
>                 err = PTR_ERR(rq);
> -               goto out_unpin;
> +               goto out_batch;
>         }
>  
> +       i915_vma_lock(batch);
> +       err = i915_vma_move_to_active(batch, rq, 0);
> +       i915_vma_unlock(batch);
> +       if (unlikely(err))
> +               goto out_request;
> +
> +       err = intel_engine_pool_mark_active(pool, rq);
> +       if (unlikely(err))
> +               goto out_request;
> +
>         err = i915_request_await_object(rq, obj, true);
>         if (unlikely(err))
>                 goto out_request;
> @@ -87,13 +158,19 @@ int i915_gem_object_fill_blt(struct drm_i915_gem_object *obj,
>         if (unlikely(err))
>                 goto out_request;
>  
> -       err = intel_emit_vma_fill_blt(rq, vma, value);
> +       err = ce->engine->emit_bb_start(rq,
> +                                       batch->node.start, batch->node.size,
> +                                       0);
>  out_request:
>         if (unlikely(err))
>                 i915_request_skip(rq, err);
>  
>         i915_request_add(rq);
> +out_batch:
> +       i915_vma_unpin(batch);
> +       intel_engine_pool_put(pool);
>  out_unpin:
> +       intel_engine_pm_put(ce->engine);
>         i915_vma_unpin(vma);
>         return err;
>  }
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_blt.h b/drivers/gpu/drm/i915/gem/i915_gem_object_blt.h
> index 7ec7de6ac0c0..a7425c234d50 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_object_blt.h
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object_blt.h
> @@ -9,13 +9,14 @@
>  #include <linux/types.h>
>  
>  struct drm_i915_gem_object;
> +struct intel_engine_pool_node;
>  struct intel_context;
> -struct i915_request;
>  struct i915_vma;
>  
> -int intel_emit_vma_fill_blt(struct i915_request *rq,
> -                           struct i915_vma *vma,
> -                           u32 value);
> +struct i915_vma *intel_emit_vma_fill_blt(struct intel_engine_pool_node **p,
> +                                        struct intel_context *ce,
> +                                        struct i915_vma *vma,
> +                                        u32 value);
>  
>  int i915_gem_object_fill_blt(struct drm_i915_gem_object *obj,
>                              struct intel_context *ce,
> 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 275c28926067..d8804a847945 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
> @@ -9,6 +9,7 @@
>  
>  #include "selftests/igt_flush_test.h"
>  #include "selftests/mock_drm.h"
> +#include "huge_gem_object.h"
>  #include "mock_context.h"
>  
>  static int igt_client_fill(void *arg)
> @@ -24,15 +25,19 @@ static int igt_client_fill(void *arg)
>         prandom_seed_state(&prng, i915_selftest.random_seed);
>  
>         do {
> -               u32 sz = prandom_u32_state(&prng) % SZ_32M;
> +               const u32 max_block_size = S16_MAX * PAGE_SIZE;
> +               u32 sz = min_t(u64, ce->vm->total >> 4, prandom_u32_state(&prng));
> +               u32 phys_sz = sz % (max_block_size + 1);
>                 u32 val = prandom_u32_state(&prng);
>                 u32 i;
>  
>                 sz = round_up(sz, PAGE_SIZE);
> +               phys_sz = round_up(phys_sz, PAGE_SIZE);
>  
> -               pr_debug("%s with sz=%x, val=%x\n", __func__, sz, val);
> +               pr_debug("%s with phys_sz= %x, sz=%x, val=%x\n", __func__,
> +                        phys_sz, sz, val);
>  
> -               obj = i915_gem_object_create_internal(i915, sz);
> +               obj = huge_gem_object(i915, phys_sz, sz);
>                 if (IS_ERR(obj)) {
>                         err = PTR_ERR(obj);
>                         goto err_flush;
> @@ -54,7 +59,8 @@ static int igt_client_fill(void *arg)
>                  * values after we do the set_to_cpu_domain and pick it up as a
>                  * test failure.
>                  */
> -               memset32(vaddr, val ^ 0xdeadbeaf, obj->base.size / sizeof(u32));
> +               memset32(vaddr, val ^ 0xdeadbeaf,
> +                        huge_gem_object_phys_size(obj) / sizeof(u32));
>  
>                 if (!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE))
>                         obj->cache_dirty = true;
> @@ -71,7 +77,7 @@ static int igt_client_fill(void *arg)
>                 if (err)
>                         goto err_unpin;
>  
> -               for (i = 0; i < obj->base.size / sizeof(u32); ++i) {
> +               for (i = 0; i < huge_gem_object_phys_size(obj) / sizeof(u32); ++i) {
>                         if (vaddr[i] != val) {
>                                 pr_err("vaddr[%u]=%x, expected=%x\n", i,
>                                        vaddr[i], val);
> diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_object_blt.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_object_blt.c
> index 19843acc84d3..c6e1eebe53f5 100644
> --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_object_blt.c
> +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_object_blt.c
> @@ -9,6 +9,7 @@
>  
>  #include "selftests/igt_flush_test.h"
>  #include "selftests/mock_drm.h"
> +#include "huge_gem_object.h"
>  #include "mock_context.h"
>  
>  static int igt_fill_blt(void *arg)
> @@ -23,16 +24,26 @@ static int igt_fill_blt(void *arg)
>  
>         prandom_seed_state(&prng, i915_selftest.random_seed);
>  
> +       /*
> +        * XXX: needs some threads to scale all these tests, also maybe throw
> +        * in submission from higher priority context to see if we are
> +        * preempted for very large objects...
> +        */

A challenge!

> +
>         do {
> -               u32 sz = prandom_u32_state(&prng) % SZ_32M;
> +               const u32 max_block_size = S16_MAX * PAGE_SIZE;
> +               u32 sz = min_t(u64, ce->vm->total >> 4, prandom_u32_state(&prng));
> +               u32 phys_sz = sz % (max_block_size + 1);
>                 u32 val = prandom_u32_state(&prng);
>                 u32 i;
>  
>                 sz = round_up(sz, PAGE_SIZE);
> +               phys_sz = round_up(phys_sz, PAGE_SIZE);
>  
> -               pr_debug("%s with sz=%x, val=%x\n", __func__, sz, val);
> +               pr_debug("%s with phys_sz= %x, sz=%x, val=%x\n", __func__,
> +                        phys_sz, sz, val);
>  
> -               obj = i915_gem_object_create_internal(i915, sz);
> +               obj = huge_gem_object(i915, phys_sz, sz);
>                 if (IS_ERR(obj)) {
>                         err = PTR_ERR(obj);
>                         goto err_flush;
> @@ -48,7 +59,8 @@ static int igt_fill_blt(void *arg)
>                  * Make sure the potentially async clflush does its job, if
>                  * required.
>                  */
> -               memset32(vaddr, val ^ 0xdeadbeaf, obj->base.size / sizeof(u32));
> +               memset32(vaddr, val ^ 0xdeadbeaf,
> +                        huge_gem_object_phys_size(obj) / sizeof(u32));

Ok, using huge_object is a little interesting for a fill as we will
write the same pages over and over again. Doesn't break the test, but it
will be important when considering doing a huge copy.

>                 if (!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE))
>                         obj->cache_dirty = true;
> @@ -65,7 +77,7 @@ static int igt_fill_blt(void *arg)
>                 if (err)
>                         goto err_unpin;
>  
> -               for (i = 0; i < obj->base.size / sizeof(u32); ++i) {
> +               for (i = 0; i < huge_gem_object_phys_size(obj) / sizeof(u32); ++i) {
>                         if (vaddr[i] != val) {
>                                 pr_err("vaddr[%u]=%x, expected=%x\n", i,
>                                        vaddr[i], val);

I thinking passing pool via batch->private isn't too bad of an idea (I
had a double take when I couldn't see an assignment to pool), but
nevertheless
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris


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