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linux-next/drivers/gpu/drm/i915/i915_gem_clflush.c
Chris Wilson b8f55be644 drm/i915: Split obj->cache_coherent to track r/w
Another month, another story in the cache coherency saga. This time, we
come to the realisation that i915_gem_object_is_coherent() has been
reporting whether we can read from the target without requiring a cache
invalidate; but we were using it in places for testing whether we could
write into the object without requiring a cache flush. So split the
tracking into two, one to decide before reads, one after writes.

See commit e27ab73d17 ("drm/i915: Mark CPU cache as dirty on every
transition for CPU writes") for the previous entry in this saga.

v2: Be verbose
v3: Remove unused function (i915_gem_object_is_coherent)
v4: Fix inverted coherency check prior to execbuf (from v2)
v5: Add comment for nasty code where we are optimising on gcc's behalf.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101109
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101555
Testcase: igt/kms_mmap_write_crc
Testcase: igt/kms_pwrite_crc
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Dongwon Kim <dongwon.kim@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Tested-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170811111116.10373-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2017-08-15 15:46:57 +01:00

185 lines
5.2 KiB
C

/*
* Copyright © 2016 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 "i915_drv.h"
#include "intel_frontbuffer.h"
#include "i915_gem_clflush.h"
static DEFINE_SPINLOCK(clflush_lock);
struct clflush {
struct dma_fence dma; /* Must be first for dma_fence_free() */
struct i915_sw_fence wait;
struct work_struct work;
struct drm_i915_gem_object *obj;
};
static const char *i915_clflush_get_driver_name(struct dma_fence *fence)
{
return DRIVER_NAME;
}
static const char *i915_clflush_get_timeline_name(struct dma_fence *fence)
{
return "clflush";
}
static bool i915_clflush_enable_signaling(struct dma_fence *fence)
{
return true;
}
static void i915_clflush_release(struct dma_fence *fence)
{
struct clflush *clflush = container_of(fence, typeof(*clflush), dma);
i915_sw_fence_fini(&clflush->wait);
BUILD_BUG_ON(offsetof(typeof(*clflush), dma));
dma_fence_free(&clflush->dma);
}
static const struct dma_fence_ops i915_clflush_ops = {
.get_driver_name = i915_clflush_get_driver_name,
.get_timeline_name = i915_clflush_get_timeline_name,
.enable_signaling = i915_clflush_enable_signaling,
.wait = dma_fence_default_wait,
.release = i915_clflush_release,
};
static void __i915_do_clflush(struct drm_i915_gem_object *obj)
{
drm_clflush_sg(obj->mm.pages);
intel_fb_obj_flush(obj, ORIGIN_CPU);
}
static void i915_clflush_work(struct work_struct *work)
{
struct clflush *clflush = container_of(work, typeof(*clflush), work);
struct drm_i915_gem_object *obj = clflush->obj;
if (i915_gem_object_pin_pages(obj)) {
DRM_ERROR("Failed to acquire obj->pages for clflushing\n");
goto out;
}
__i915_do_clflush(obj);
i915_gem_object_unpin_pages(obj);
out:
i915_gem_object_put(obj);
dma_fence_signal(&clflush->dma);
dma_fence_put(&clflush->dma);
}
static int __i915_sw_fence_call
i915_clflush_notify(struct i915_sw_fence *fence,
enum i915_sw_fence_notify state)
{
struct clflush *clflush = container_of(fence, typeof(*clflush), wait);
switch (state) {
case FENCE_COMPLETE:
schedule_work(&clflush->work);
break;
case FENCE_FREE:
dma_fence_put(&clflush->dma);
break;
}
return NOTIFY_DONE;
}
bool i915_gem_clflush_object(struct drm_i915_gem_object *obj,
unsigned int flags)
{
struct clflush *clflush;
/*
* Stolen memory is always coherent with the GPU as it is explicitly
* marked as wc by the system, or the system is cache-coherent.
* Similarly, we only access struct pages through the CPU cache, so
* anything not backed by physical memory we consider to be always
* coherent and not need clflushing.
*/
if (!i915_gem_object_has_struct_page(obj)) {
obj->cache_dirty = false;
return false;
}
/* If the GPU is snooping the contents of the CPU cache,
* we do not need to manually clear the CPU cache lines. However,
* the caches are only snooped when the render cache is
* flushed/invalidated. As we always have to emit invalidations
* and flushes when moving into and out of the RENDER domain, correct
* snooping behaviour occurs naturally as the result of our domain
* tracking.
*/
if (!(flags & I915_CLFLUSH_FORCE) &&
obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ)
return false;
trace_i915_gem_object_clflush(obj);
clflush = NULL;
if (!(flags & I915_CLFLUSH_SYNC))
clflush = kmalloc(sizeof(*clflush), GFP_KERNEL);
if (clflush) {
GEM_BUG_ON(!obj->cache_dirty);
dma_fence_init(&clflush->dma,
&i915_clflush_ops,
&clflush_lock,
to_i915(obj->base.dev)->mm.unordered_timeline,
0);
i915_sw_fence_init(&clflush->wait, i915_clflush_notify);
clflush->obj = i915_gem_object_get(obj);
INIT_WORK(&clflush->work, i915_clflush_work);
dma_fence_get(&clflush->dma);
i915_sw_fence_await_reservation(&clflush->wait,
obj->resv, NULL,
true, I915_FENCE_TIMEOUT,
GFP_KERNEL);
reservation_object_lock(obj->resv, NULL);
reservation_object_add_excl_fence(obj->resv, &clflush->dma);
reservation_object_unlock(obj->resv);
i915_sw_fence_commit(&clflush->wait);
} else if (obj->mm.pages) {
__i915_do_clflush(obj);
} else {
GEM_BUG_ON(obj->base.write_domain != I915_GEM_DOMAIN_CPU);
}
obj->cache_dirty = false;
return true;
}