From ef74921bc679232c6590afa881d3ea605ebdddd8 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 12 Apr 2017 12:01:10 +0100 Subject: [PATCH] drm/i915: Combine write_domain flushes to a single function In the next patch, we will introduce a new cache domain for differentiating between GTT access and direct WC access. This will require us to include WC in our write_domain flushes. Rather than duplicate a third function, combine the existing two into one and flushing WC writes will then be automatically handled as well. v2: Be smarter and clearer by passing in the write domains to flush (Joonas) v3: One missed ~ in v2 conversion Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Reviewed-by: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/20170412110111.26626-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem.c | 125 +++++++++--------- .../drm/i915/selftests/i915_gem_coherency.c | 4 +- .../gpu/drm/i915/selftests/i915_gem_object.c | 2 +- 3 files changed, 64 insertions(+), 67 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index cb8c6a94ba4e..f1c28668edbf 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -46,8 +46,6 @@ #include static void i915_gem_flush_free_objects(struct drm_i915_private *i915); -static void i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj); -static void i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj); static bool cpu_write_needs_clflush(struct drm_i915_gem_object *obj) { @@ -705,6 +703,61 @@ i915_gem_create_ioctl(struct drm_device *dev, void *data, args->size, &args->handle); } +static inline enum fb_op_origin +fb_write_origin(struct drm_i915_gem_object *obj, unsigned int domain) +{ + return (domain == I915_GEM_DOMAIN_GTT ? + obj->frontbuffer_ggtt_origin : ORIGIN_CPU); +} + +static void +flush_write_domain(struct drm_i915_gem_object *obj, unsigned int flush_domains) +{ + struct drm_i915_private *dev_priv = to_i915(obj->base.dev); + + if (!(obj->base.write_domain & flush_domains)) + return; + + /* No actual flushing is required for the GTT write domain. Writes + * to it "immediately" go to main memory as far as we know, so there's + * no chipset flush. It also doesn't land in render cache. + * + * However, we do have to enforce the order so that all writes through + * the GTT land before any writes to the device, such as updates to + * the GATT itself. + * + * We also have to wait a bit for the writes to land from the GTT. + * An uncached read (i.e. mmio) seems to be ideal for the round-trip + * timing. This issue has only been observed when switching quickly + * between GTT writes and CPU reads from inside the kernel on recent hw, + * and it appears to only affect discrete GTT blocks (i.e. on LLC + * system agents we cannot reproduce this behaviour). + */ + wmb(); + + switch (obj->base.write_domain) { + case I915_GEM_DOMAIN_GTT: + if (INTEL_GEN(dev_priv) >= 6 && !HAS_LLC(dev_priv)) { + if (intel_runtime_pm_get_if_in_use(dev_priv)) { + spin_lock_irq(&dev_priv->uncore.lock); + POSTING_READ_FW(RING_ACTHD(dev_priv->engine[RCS]->mmio_base)); + spin_unlock_irq(&dev_priv->uncore.lock); + intel_runtime_pm_put(dev_priv); + } + } + + intel_fb_obj_flush(obj, + fb_write_origin(obj, I915_GEM_DOMAIN_GTT)); + break; + + case I915_GEM_DOMAIN_CPU: + i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC); + break; + } + + obj->base.write_domain = 0; +} + static inline int __copy_to_user_swizzled(char __user *cpu_vaddr, const char *gpu_vaddr, int gpu_offset, @@ -794,7 +847,7 @@ int i915_gem_obj_prepare_shmem_read(struct drm_i915_gem_object *obj, goto out; } - i915_gem_object_flush_gtt_write_domain(obj); + flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU); /* If we're not in the cpu read domain, set ourself into the gtt * read domain and manually flush cachelines (if required). This @@ -846,7 +899,7 @@ int i915_gem_obj_prepare_shmem_write(struct drm_i915_gem_object *obj, goto out; } - i915_gem_object_flush_gtt_write_domain(obj); + flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU); /* If we're not in the cpu write domain, set ourself into the * gtt write domain and manually flush cachelines (as required). @@ -1501,13 +1554,6 @@ err: return ret; } -static inline enum fb_op_origin -write_origin(struct drm_i915_gem_object *obj, unsigned domain) -{ - return (domain == I915_GEM_DOMAIN_GTT ? - obj->frontbuffer_ggtt_origin : ORIGIN_CPU); -} - static void i915_gem_object_bump_inactive_ggtt(struct drm_i915_gem_object *obj) { struct drm_i915_private *i915; @@ -1602,7 +1648,8 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data, mutex_unlock(&dev->struct_mutex); if (write_domain != 0) - intel_fb_obj_invalidate(obj, write_origin(obj, write_domain)); + intel_fb_obj_invalidate(obj, + fb_write_origin(obj, write_domain)); out_unpin: i915_gem_object_unpin_pages(obj); @@ -3320,56 +3367,6 @@ int i915_gem_wait_for_idle(struct drm_i915_private *i915, unsigned int flags) return ret; } -/** Flushes the GTT write domain for the object if it's dirty. */ -static void -i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj) -{ - struct drm_i915_private *dev_priv = to_i915(obj->base.dev); - - if (obj->base.write_domain != I915_GEM_DOMAIN_GTT) - return; - - /* No actual flushing is required for the GTT write domain. Writes - * to it "immediately" go to main memory as far as we know, so there's - * no chipset flush. It also doesn't land in render cache. - * - * However, we do have to enforce the order so that all writes through - * the GTT land before any writes to the device, such as updates to - * the GATT itself. - * - * We also have to wait a bit for the writes to land from the GTT. - * An uncached read (i.e. mmio) seems to be ideal for the round-trip - * timing. This issue has only been observed when switching quickly - * between GTT writes and CPU reads from inside the kernel on recent hw, - * and it appears to only affect discrete GTT blocks (i.e. on LLC - * system agents we cannot reproduce this behaviour). - */ - wmb(); - if (INTEL_GEN(dev_priv) >= 6 && !HAS_LLC(dev_priv)) { - if (intel_runtime_pm_get_if_in_use(dev_priv)) { - spin_lock_irq(&dev_priv->uncore.lock); - POSTING_READ_FW(RING_ACTHD(dev_priv->engine[RCS]->mmio_base)); - spin_unlock_irq(&dev_priv->uncore.lock); - intel_runtime_pm_put(dev_priv); - } - } - - intel_fb_obj_flush(obj, write_origin(obj, I915_GEM_DOMAIN_GTT)); - - obj->base.write_domain = 0; -} - -/** Flushes the CPU write domain for the object if it's dirty. */ -static void -i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj) -{ - if (obj->base.write_domain != I915_GEM_DOMAIN_CPU) - return; - - i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC); - obj->base.write_domain = 0; -} - static void __i915_gem_object_flush_for_display(struct drm_i915_gem_object *obj) { if (obj->base.write_domain != I915_GEM_DOMAIN_CPU && !obj->cache_dirty) @@ -3428,7 +3425,7 @@ i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write) if (ret) return ret; - i915_gem_object_flush_cpu_write_domain(obj); + flush_write_domain(obj, ~I915_GEM_DOMAIN_GTT); /* Serialise direct access to this object with the barriers for * coherent writes from the GPU, by effectively invalidating the @@ -3802,7 +3799,7 @@ i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write) if (obj->base.write_domain == I915_GEM_DOMAIN_CPU) return 0; - i915_gem_object_flush_gtt_write_domain(obj); + flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU); /* Flush the CPU cache if it's still invalid. */ if ((obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0) { diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c b/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c index f08d0179b3df..c61d0ef2118c 100644 --- a/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c +++ b/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c @@ -139,7 +139,7 @@ static int wc_set(struct drm_i915_gem_object *obj, int err; /* XXX GTT write followed by WC write go missing */ - i915_gem_object_flush_gtt_write_domain(obj); + flush_write_domain(obj, ~0); err = i915_gem_object_set_to_gtt_domain(obj, true); if (err) @@ -163,7 +163,7 @@ static int wc_get(struct drm_i915_gem_object *obj, int err; /* XXX WC write followed by GTT write go missing */ - i915_gem_object_flush_gtt_write_domain(obj); + flush_write_domain(obj, ~0); err = i915_gem_object_set_to_gtt_domain(obj, false); if (err) diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_object.c b/drivers/gpu/drm/i915/selftests/i915_gem_object.c index 67d82bf1407f..163424748ee0 100644 --- a/drivers/gpu/drm/i915/selftests/i915_gem_object.c +++ b/drivers/gpu/drm/i915/selftests/i915_gem_object.c @@ -266,7 +266,7 @@ static int check_partial_mapping(struct drm_i915_gem_object *obj, if (offset >= obj->base.size) continue; - i915_gem_object_flush_gtt_write_domain(obj); + flush_write_domain(obj, ~I915_GEM_DOMAIN_CPU); p = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT); cpu = kmap(p) + offset_in_page(offset); -- 2.20.1