[PATCH 18/18] manual-waits
Chris Wilson
chris at chris-wilson.co.uk
Sat Jan 2 13:20:22 UTC 2021
---
drivers/gpu/drm/i915/gem/i915_gem_clflush.c | 6 +-
drivers/gpu/drm/i915/gem/i915_gem_clflush.h | 2 -
drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 4 +-
drivers/gpu/drm/i915/gem/i915_gem_domain.c | 157 +++++-------------
drivers/gpu/drm/i915/gem/i915_gem_object.h | 12 +-
.../gpu/drm/i915/gem/i915_gem_object_types.h | 6 +
.../gpu/drm/i915/gem/selftests/huge_pages.c | 8 -
.../i915/gem/selftests/i915_gem_coherency.c | 30 +++-
.../drm/i915/gem/selftests/i915_gem_phys.c | 8 +-
.../drm/i915/gem/selftests/igt_gem_utils.c | 3 +
drivers/gpu/drm/i915/i915_gem.c | 12 +-
11 files changed, 88 insertions(+), 160 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
index bc0223716906..14c1f6244d5f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
@@ -57,8 +57,6 @@ static struct clflush *clflush_work_create(struct drm_i915_gem_object *obj)
{
struct clflush *clflush;
- GEM_BUG_ON(!obj->cache_dirty);
-
clflush = kmalloc(sizeof(*clflush), GFP_KERNEL);
if (!clflush)
return NULL;
@@ -102,9 +100,7 @@ bool i915_gem_clflush_object(struct drm_i915_gem_object *obj,
trace_i915_gem_object_clflush(obj);
- clflush = NULL;
- if (!(flags & I915_CLFLUSH_SYNC))
- clflush = clflush_work_create(obj);
+ clflush = clflush_work_create(obj);
if (clflush) {
i915_sw_fence_await_reservation(&clflush->base.chain,
obj->base.resv, NULL, true,
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_clflush.h b/drivers/gpu/drm/i915/gem/i915_gem_clflush.h
index e6c382973129..4cd5787d1507 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_clflush.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_clflush.h
@@ -9,12 +9,10 @@
#include <linux/types.h>
-struct drm_i915_private;
struct drm_i915_gem_object;
bool i915_gem_clflush_object(struct drm_i915_gem_object *obj,
unsigned int flags);
#define I915_CLFLUSH_FORCE BIT(0)
-#define I915_CLFLUSH_SYNC BIT(1)
#endif /* __I915_GEM_CLFLUSH_H__ */
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index 04e9c04545ad..6229f80f7c3f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -133,7 +133,7 @@ static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_dire
if (err)
goto out;
- err = i915_gem_object_set_to_cpu_domain(obj, write);
+ i915_gem_object_set_to_cpu_domain(obj, write);
i915_gem_object_unlock(obj);
out:
@@ -154,7 +154,7 @@ static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direct
if (err)
goto out;
- err = i915_gem_object_set_to_gtt_domain(obj, false);
+ i915_gem_object_set_to_gtt_domain(obj, false);
i915_gem_object_unlock(obj);
out:
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
index 666e4c60d610..22b2ffa2a262 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
@@ -49,7 +49,7 @@ flush_write_domain(struct drm_i915_gem_object *obj, unsigned int flush_domains)
break;
case I915_GEM_DOMAIN_CPU:
- i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC);
+ i915_gem_clflush_object(obj, 0);
break;
case I915_GEM_DOMAIN_RENDER:
@@ -97,34 +97,13 @@ void i915_gem_object_flush_if_display_locked(struct drm_i915_gem_object *obj)
* This function returns when the move is complete, including waiting on
* flushes to occur.
*/
-int
+void
i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write)
{
- int ret;
-
assert_object_held(obj);
- ret = i915_gem_object_wait(obj,
- I915_WAIT_INTERRUPTIBLE |
- (write ? I915_WAIT_ALL : 0),
- MAX_SCHEDULE_TIMEOUT);
- if (ret)
- return ret;
-
if (obj->write_domain == I915_GEM_DOMAIN_WC)
- return 0;
-
- /* Flush and acquire obj->pages so that we are coherent through
- * direct access in memory with previous cached writes through
- * shmemfs and that our cache domain tracking remains valid.
- * For example, if the obj->filp was moved to swap without us
- * being notified and releasing the pages, we would mistakenly
- * continue to assume that the obj remained out of the CPU cached
- * domain.
- */
- ret = i915_gem_object_pin_pages(obj);
- if (ret)
- return ret;
+ return;
flush_write_domain(obj, ~I915_GEM_DOMAIN_WC);
@@ -145,9 +124,6 @@ i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write)
obj->write_domain = I915_GEM_DOMAIN_WC;
obj->mm.dirty = true;
}
-
- i915_gem_object_unpin_pages(obj);
- return 0;
}
/**
@@ -158,34 +134,13 @@ i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write)
* This function returns when the move is complete, including waiting on
* flushes to occur.
*/
-int
+void
i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
{
- int ret;
-
assert_object_held(obj);
- ret = i915_gem_object_wait(obj,
- I915_WAIT_INTERRUPTIBLE |
- (write ? I915_WAIT_ALL : 0),
- MAX_SCHEDULE_TIMEOUT);
- if (ret)
- return ret;
-
if (obj->write_domain == I915_GEM_DOMAIN_GTT)
- return 0;
-
- /* Flush and acquire obj->pages so that we are coherent through
- * direct access in memory with previous cached writes through
- * shmemfs and that our cache domain tracking remains valid.
- * For example, if the obj->filp was moved to swap without us
- * being notified and releasing the pages, we would mistakenly
- * continue to assume that the obj remained out of the CPU cached
- * domain.
- */
- ret = i915_gem_object_pin_pages(obj);
- if (ret)
- return ret;
+ return;
flush_write_domain(obj, ~I915_GEM_DOMAIN_GTT);
@@ -214,9 +169,6 @@ i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
i915_vma_set_ggtt_write(vma);
spin_unlock(&obj->vma.lock);
}
-
- i915_gem_object_unpin_pages(obj);
- return 0;
}
/**
@@ -441,25 +393,23 @@ i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
* This function returns when the move is complete, including waiting on
* flushes to occur.
*/
-int
+void
i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write)
{
- int ret;
-
assert_object_held(obj);
- ret = i915_gem_object_wait(obj,
- I915_WAIT_INTERRUPTIBLE |
- (write ? I915_WAIT_ALL : 0),
- MAX_SCHEDULE_TIMEOUT);
- if (ret)
- return ret;
-
flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
/* Flush the CPU cache if it's still invalid. */
if ((obj->read_domains & I915_GEM_DOMAIN_CPU) == 0) {
- i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC);
+ /*
+ * While we track when we write though the CPU cache
+ * (with obj->cache_dirty), this is only a guide as we do
+ * not know when the CPU may have speculatively populated
+ * the cache. We have to invalidate such speculative cachelines
+ * prior to reading writes by the GPU.
+ */
+ i915_gem_clflush_object(obj, 0);
obj->read_domains |= I915_GEM_DOMAIN_CPU;
}
@@ -473,8 +423,6 @@ i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write)
*/
if (write)
__start_cpu_write(obj);
-
- return 0;
}
/**
@@ -512,19 +460,6 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
if (!obj)
return -ENOENT;
- /*
- * Try to flush the object off the GPU without holding the lock.
- * We will repeat the flush holding the lock in the normal manner
- * to catch cases where we are gazumped.
- */
- err = i915_gem_object_wait(obj,
- I915_WAIT_INTERRUPTIBLE |
- I915_WAIT_PRIORITY |
- (write_domain ? I915_WAIT_ALL : 0),
- MAX_SCHEDULE_TIMEOUT);
- if (err)
- goto out;
-
/*
* Proxy objects do not control access to the backing storage, ergo
* they cannot be used as a means to manipulate the cache domain
@@ -560,21 +495,27 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
* without having to further check the requested write_domain.
*/
if (READ_ONCE(obj->write_domain) == read_domains)
- goto out_unpin;
+ goto out_wait;
err = i915_gem_object_lock_interruptible(obj, NULL);
if (err)
goto out_unpin;
if (read_domains & I915_GEM_DOMAIN_WC)
- err = i915_gem_object_set_to_wc_domain(obj, write_domain);
+ i915_gem_object_set_to_wc_domain(obj, write_domain);
else if (read_domains & I915_GEM_DOMAIN_GTT)
- err = i915_gem_object_set_to_gtt_domain(obj, write_domain);
+ i915_gem_object_set_to_gtt_domain(obj, write_domain);
else
- err = i915_gem_object_set_to_cpu_domain(obj, write_domain);
+ i915_gem_object_set_to_cpu_domain(obj, write_domain);
i915_gem_object_unlock(obj);
+out_wait:
+ err = i915_gem_object_wait(obj,
+ I915_WAIT_INTERRUPTIBLE |
+ I915_WAIT_PRIORITY |
+ (write_domain ? I915_WAIT_ALL : 0),
+ MAX_SCHEDULE_TIMEOUT);
if (write_domain)
i915_gem_object_invalidate_frontbuffer(obj, ORIGIN_CPU);
@@ -601,26 +542,21 @@ int i915_gem_object_prepare_read(struct drm_i915_gem_object *obj,
assert_object_held(obj);
- ret = i915_gem_object_wait(obj,
- I915_WAIT_INTERRUPTIBLE,
- MAX_SCHEDULE_TIMEOUT);
- if (ret)
- return ret;
-
ret = i915_gem_object_pin_pages(obj);
if (ret)
return ret;
if (obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ ||
- !static_cpu_has(X86_FEATURE_CLFLUSH)) {
- ret = i915_gem_object_set_to_cpu_domain(obj, false);
- if (ret)
- goto err_unpin;
- else
- goto out;
- }
+ !static_cpu_has(X86_FEATURE_CLFLUSH))
+ i915_gem_object_set_to_cpu_domain(obj, false);
+ else
+ flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
- flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
+ ret = i915_gem_object_wait(obj,
+ I915_WAIT_INTERRUPTIBLE,
+ MAX_SCHEDULE_TIMEOUT);
+ if (ret)
+ goto err_unpin;
/* If we're not in the cpu read domain, set ourself into the gtt
* read domain and manually flush cachelines (if required). This
@@ -631,7 +567,6 @@ int i915_gem_object_prepare_read(struct drm_i915_gem_object *obj,
!(obj->read_domains & I915_GEM_DOMAIN_CPU))
*needs_clflush = CLFLUSH_BEFORE;
-out:
/* return with the pages pinned */
return 0;
@@ -651,27 +586,22 @@ int i915_gem_object_prepare_write(struct drm_i915_gem_object *obj,
assert_object_held(obj);
- ret = i915_gem_object_wait(obj,
- I915_WAIT_INTERRUPTIBLE |
- I915_WAIT_ALL,
- MAX_SCHEDULE_TIMEOUT);
- if (ret)
- return ret;
-
ret = i915_gem_object_pin_pages(obj);
if (ret)
return ret;
if (obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE ||
- !static_cpu_has(X86_FEATURE_CLFLUSH)) {
- ret = i915_gem_object_set_to_cpu_domain(obj, true);
- if (ret)
- goto err_unpin;
- else
- goto out;
- }
+ !static_cpu_has(X86_FEATURE_CLFLUSH))
+ i915_gem_object_set_to_cpu_domain(obj, true);
+ else
+ flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
- flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU);
+ ret = i915_gem_object_wait(obj,
+ I915_WAIT_INTERRUPTIBLE |
+ I915_WAIT_ALL,
+ MAX_SCHEDULE_TIMEOUT);
+ if (ret)
+ goto err_unpin;
/* If we're not in the cpu write domain, set ourself into the
* gtt write domain and manually flush cachelines (as required).
@@ -689,7 +619,6 @@ int i915_gem_object_prepare_write(struct drm_i915_gem_object *obj,
*needs_clflush |= CLFLUSH_BEFORE;
}
-out:
i915_gem_object_invalidate_frontbuffer(obj, ORIGIN_CPU);
obj->mm.dirty = true;
/* return with the pages pinned */
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index 7d441df7c6bc..4efc3b7cbbbf 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -471,12 +471,12 @@ void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj,
void i915_gem_object_flush_if_display(struct drm_i915_gem_object *obj);
void i915_gem_object_flush_if_display_locked(struct drm_i915_gem_object *obj);
-int __must_check
-i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write);
-int __must_check
-i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write);
-int __must_check
-i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write);
+void i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj,
+ bool write);
+void i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj,
+ bool write);
+void i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj,
+ bool write);
struct i915_vma * __must_check
i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
u32 alignment,
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 0865c7500c6d..64ae92c6755e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -175,6 +175,12 @@ struct drm_i915_gem_object {
unsigned int cache_coherent:2;
#define I915_BO_CACHE_COHERENT_FOR_READ BIT(0)
#define I915_BO_CACHE_COHERENT_FOR_WRITE BIT(1)
+ /*
+ * Note cache_dirty is only a guide; we know when we have written
+ * through the CPU cache, but we do not know when the CPU may have
+ * speculatively populated the cache. Before a read via the cache
+ * of GPU written memory, we have to cautiously invalidate the cache.
+ */
unsigned int cache_dirty:1;
/**
diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
index f6329e462cfc..10ee24b252dd 100644
--- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
@@ -962,14 +962,6 @@ static int gpu_write(struct intel_context *ce,
u32 dw,
u32 val)
{
- int err;
-
- i915_gem_object_lock(vma->obj, NULL);
- err = i915_gem_object_set_to_gtt_domain(vma->obj, true);
- i915_gem_object_unlock(vma->obj);
- if (err)
- return err;
-
return igt_gpu_fill_dw(ce, vma, dw * sizeof(u32),
vma->size >> PAGE_SHIFT, val);
}
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c
index 1117d2a44518..b5dbf15570fc 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c
@@ -90,8 +90,13 @@ static int gtt_set(struct context *ctx, unsigned long offset, u32 v)
int err = 0;
i915_gem_object_lock(ctx->obj, NULL);
- err = i915_gem_object_set_to_gtt_domain(ctx->obj, true);
+ i915_gem_object_set_to_gtt_domain(ctx->obj, true);
i915_gem_object_unlock(ctx->obj);
+
+ err = i915_gem_object_wait(ctx->obj,
+ I915_WAIT_ALL |
+ I915_WAIT_INTERRUPTIBLE,
+ HZ / 2);
if (err)
return err;
@@ -123,8 +128,12 @@ static int gtt_get(struct context *ctx, unsigned long offset, u32 *v)
int err = 0;
i915_gem_object_lock(ctx->obj, NULL);
- err = i915_gem_object_set_to_gtt_domain(ctx->obj, false);
+ i915_gem_object_set_to_gtt_domain(ctx->obj, false);
i915_gem_object_unlock(ctx->obj);
+
+ err = i915_gem_object_wait(ctx->obj,
+ I915_WAIT_INTERRUPTIBLE,
+ HZ / 2);
if (err)
return err;
@@ -155,8 +164,13 @@ static int wc_set(struct context *ctx, unsigned long offset, u32 v)
int err;
i915_gem_object_lock(ctx->obj, NULL);
- err = i915_gem_object_set_to_wc_domain(ctx->obj, true);
+ i915_gem_object_set_to_wc_domain(ctx->obj, true);
i915_gem_object_unlock(ctx->obj);
+
+ err = i915_gem_object_wait(ctx->obj,
+ I915_WAIT_ALL |
+ I915_WAIT_INTERRUPTIBLE,
+ HZ / 2);
if (err)
return err;
@@ -178,8 +192,12 @@ static int wc_get(struct context *ctx, unsigned long offset, u32 *v)
int err;
i915_gem_object_lock(ctx->obj, NULL);
- err = i915_gem_object_set_to_wc_domain(ctx->obj, false);
+ i915_gem_object_set_to_wc_domain(ctx->obj, false);
i915_gem_object_unlock(ctx->obj);
+
+ err = i915_gem_object_wait(ctx->obj,
+ I915_WAIT_INTERRUPTIBLE,
+ HZ / 2);
if (err)
return err;
@@ -201,9 +219,7 @@ static int gpu_set(struct context *ctx, unsigned long offset, u32 v)
int err;
i915_gem_object_lock(ctx->obj, NULL);
- err = i915_gem_object_set_to_gtt_domain(ctx->obj, true);
- if (err)
- goto out_unlock;
+ i915_gem_object_set_to_gtt_domain(ctx->obj, false);
vma = i915_gem_object_ggtt_pin(ctx->obj, NULL, 0, 0, 0);
if (IS_ERR(vma)) {
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_phys.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_phys.c
index 8cee68c6a6dc..b62d02cb9579 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_phys.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_phys.c
@@ -45,14 +45,10 @@ static int mock_phys_object(void *arg)
/* Make the object dirty so that put_pages must do copy back the data */
i915_gem_object_lock(obj, NULL);
- err = i915_gem_object_set_to_gtt_domain(obj, true);
+ i915_gem_object_set_to_gtt_domain(obj, true);
i915_gem_object_unlock(obj);
- if (err) {
- pr_err("i915_gem_object_set_to_gtt_domain failed with err=%d\n",
- err);
- goto out_obj;
- }
+ err = 0;
out_obj:
i915_gem_object_put(obj);
out:
diff --git a/drivers/gpu/drm/i915/gem/selftests/igt_gem_utils.c b/drivers/gpu/drm/i915/gem/selftests/igt_gem_utils.c
index d6783061bc72..b7e064667d39 100644
--- a/drivers/gpu/drm/i915/gem/selftests/igt_gem_utils.c
+++ b/drivers/gpu/drm/i915/gem/selftests/igt_gem_utils.c
@@ -7,6 +7,7 @@
#include "igt_gem_utils.h"
#include "gem/i915_gem_context.h"
+#include "gem/i915_gem_clflush.h"
#include "gem/i915_gem_pm.h"
#include "gt/intel_context.h"
#include "gt/intel_gpu_commands.h"
@@ -138,6 +139,8 @@ int igt_gpu_fill_dw(struct intel_context *ce,
goto skip_request;
i915_vma_lock(vma);
+ if (vma->obj->cache_dirty & ~vma->obj->cache_coherent)
+ i915_gem_clflush_object(vma->obj, 0);
err = i915_request_await_object(rq, vma->obj, true);
if (err == 0)
err = i915_vma_move_to_active(vma, rq, EXEC_OBJECT_WRITE);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 7e66d450e537..2747ef1e89fc 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -408,11 +408,7 @@ i915_gem_gtt_pread(struct drm_i915_gem_object *obj,
if (ret)
goto out_unpin;
- ret = i915_gem_object_set_to_gtt_domain(obj, false);
- if (ret) {
- i915_gem_object_unlock(obj);
- goto out_unpin;
- }
+ i915_gem_object_set_to_gtt_domain(obj, false);
fence = i915_gem_object_lock_fence(obj);
i915_gem_object_unlock(obj);
@@ -613,11 +609,7 @@ i915_gem_gtt_pwrite_fast(struct drm_i915_gem_object *obj,
if (ret)
goto out_unpin;
- ret = i915_gem_object_set_to_gtt_domain(obj, true);
- if (ret) {
- i915_gem_object_unlock(obj);
- goto out_unpin;
- }
+ i915_gem_object_set_to_gtt_domain(obj, true);
fence = i915_gem_object_lock_fence(obj);
i915_gem_object_unlock(obj);
--
2.20.1
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