From b45305fce5bb1abec263fcff9d81ebecd6306ede Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 17 Dec 2012 16:21:27 +0100 Subject: drm/i915: Implement workaround for broken CS tlb on i830/845 Now that Chris Wilson demonstrated that the key for stability on early gen 2 is to simple _never_ exchange the physical backing storage of batch buffers I've tried a stab at a kernel solution. Doesn't look too nefarious imho, now that I don't try to be too clever for my own good any more. v2: After discussing the various techniques, we've decided to always blit batches on the suspect devices, but allow userspace to opt out of the kernel workaround assume full responsibility for providing coherent batches. The principal reason is that avoiding the blit does improve performance in a few key microbenchmarks and also in cairo-trace replays. Signed-Off-by: Daniel Vetter Signed-off-by: Chris Wilson [danvet: - Drop the hunk which uses HAS_BROKEN_CS_TLB to implement the ring wrap w/a. Suggested by Chris Wilson. - Also add the ACTHD check from Chris Wilson for the error state dumping, so that we still catch batches when userspace opts out of the w/a.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_dma.c | 3 ++ drivers/gpu/drm/i915/i915_drv.h | 4 ++ drivers/gpu/drm/i915/i915_gem_execbuffer.c | 2 + drivers/gpu/drm/i915/i915_irq.c | 12 +++++ drivers/gpu/drm/i915/intel_ringbuffer.c | 76 ++++++++++++++++++++++++++---- drivers/gpu/drm/i915/intel_ringbuffer.h | 1 + 6 files changed, 90 insertions(+), 8 deletions(-) (limited to 'drivers/gpu/drm') diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 8f63cd5de4b..99daa896105 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -989,6 +989,9 @@ static int i915_getparam(struct drm_device *dev, void *data, case I915_PARAM_HAS_SECURE_BATCHES: value = capable(CAP_SYS_ADMIN); break; + case I915_PARAM_HAS_PINNED_BATCHES: + value = 1; + break; default: DRM_DEBUG_DRIVER("Unknown parameter %d\n", param->param); diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 062a60b381b..1a4c3a1c111 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1100,6 +1100,7 @@ struct drm_i915_gem_object { */ atomic_t pending_flip; }; +#define to_gem_object(obj) (&((struct drm_i915_gem_object *)(obj))->base) #define to_intel_bo(x) container_of(x, struct drm_i915_gem_object, base) @@ -1199,6 +1200,9 @@ struct drm_i915_file_private { #define HAS_OVERLAY(dev) (INTEL_INFO(dev)->has_overlay) #define OVERLAY_NEEDS_PHYSICAL(dev) (INTEL_INFO(dev)->overlay_needs_physical) +/* Early gen2 have a totally busted CS tlb and require pinned batches. */ +#define HAS_BROKEN_CS_TLB(dev) (IS_I830(dev) || IS_845G(dev)) + /* With the 945 and later, Y tiling got adjusted so that it was 32 128-byte * rows, which changed the alignment requirements and fence programming. */ diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index ee8f97f0539..d6a994a0739 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -808,6 +808,8 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data, flags |= I915_DISPATCH_SECURE; } + if (args->flags & I915_EXEC_IS_PINNED) + flags |= I915_DISPATCH_PINNED; switch (args->flags & I915_EXEC_RING_MASK) { case I915_EXEC_DEFAULT: diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index a4dc97f8b9f..2220dec3e5d 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1087,6 +1087,18 @@ i915_error_first_batchbuffer(struct drm_i915_private *dev_priv, if (!ring->get_seqno) return NULL; + if (HAS_BROKEN_CS_TLB(dev_priv->dev)) { + u32 acthd = I915_READ(ACTHD); + + if (WARN_ON(ring->id != RCS)) + return NULL; + + obj = ring->private; + if (acthd >= obj->gtt_offset && + acthd < obj->gtt_offset + obj->base.size) + return i915_error_object_create(dev_priv, obj); + } + seqno = ring->get_seqno(ring, false); list_for_each_entry(obj, &dev_priv->mm.active_list, mm_list) { if (obj->ring != ring) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 2346b920bd8..ae253e04c39 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -547,9 +547,14 @@ static int init_render_ring(struct intel_ring_buffer *ring) static void render_ring_cleanup(struct intel_ring_buffer *ring) { + struct drm_device *dev = ring->dev; + if (!ring->private) return; + if (HAS_BROKEN_CS_TLB(dev)) + drm_gem_object_unreference(to_gem_object(ring->private)); + cleanup_pipe_control(ring); } @@ -969,6 +974,8 @@ i965_dispatch_execbuffer(struct intel_ring_buffer *ring, return 0; } +/* Just userspace ABI convention to limit the wa batch bo to a resonable size */ +#define I830_BATCH_LIMIT (256*1024) static int i830_dispatch_execbuffer(struct intel_ring_buffer *ring, u32 offset, u32 len, @@ -976,15 +983,47 @@ i830_dispatch_execbuffer(struct intel_ring_buffer *ring, { int ret; - ret = intel_ring_begin(ring, 4); - if (ret) - return ret; + if (flags & I915_DISPATCH_PINNED) { + ret = intel_ring_begin(ring, 4); + if (ret) + return ret; - intel_ring_emit(ring, MI_BATCH_BUFFER); - intel_ring_emit(ring, offset | (flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE)); - intel_ring_emit(ring, offset + len - 8); - intel_ring_emit(ring, 0); - intel_ring_advance(ring); + intel_ring_emit(ring, MI_BATCH_BUFFER); + intel_ring_emit(ring, offset | (flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE)); + intel_ring_emit(ring, offset + len - 8); + intel_ring_emit(ring, MI_NOOP); + intel_ring_advance(ring); + } else { + struct drm_i915_gem_object *obj = ring->private; + u32 cs_offset = obj->gtt_offset; + + if (len > I830_BATCH_LIMIT) + return -ENOSPC; + + ret = intel_ring_begin(ring, 9+3); + if (ret) + return ret; + /* Blit the batch (which has now all relocs applied) to the stable batch + * scratch bo area (so that the CS never stumbles over its tlb + * invalidation bug) ... */ + intel_ring_emit(ring, XY_SRC_COPY_BLT_CMD | + XY_SRC_COPY_BLT_WRITE_ALPHA | + XY_SRC_COPY_BLT_WRITE_RGB); + intel_ring_emit(ring, BLT_DEPTH_32 | BLT_ROP_GXCOPY | 4096); + intel_ring_emit(ring, 0); + intel_ring_emit(ring, (DIV_ROUND_UP(len, 4096) << 16) | 1024); + intel_ring_emit(ring, cs_offset); + intel_ring_emit(ring, 0); + intel_ring_emit(ring, 4096); + intel_ring_emit(ring, offset); + intel_ring_emit(ring, MI_FLUSH); + + /* ... and execute it. */ + intel_ring_emit(ring, MI_BATCH_BUFFER); + intel_ring_emit(ring, cs_offset | (flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE)); + intel_ring_emit(ring, cs_offset + len - 8); + intel_ring_advance(ring); + } return 0; } @@ -1596,6 +1635,27 @@ int intel_init_render_ring_buffer(struct drm_device *dev) ring->init = init_render_ring; ring->cleanup = render_ring_cleanup; + /* Workaround batchbuffer to combat CS tlb bug. */ + if (HAS_BROKEN_CS_TLB(dev)) { + struct drm_i915_gem_object *obj; + int ret; + + obj = i915_gem_alloc_object(dev, I830_BATCH_LIMIT); + if (obj == NULL) { + DRM_ERROR("Failed to allocate batch bo\n"); + return -ENOMEM; + } + + ret = i915_gem_object_pin(obj, 0, true, false); + if (ret != 0) { + drm_gem_object_unreference(&obj->base); + DRM_ERROR("Failed to ping batch bo\n"); + return ret; + } + + ring->private = obj; + } + return intel_init_ring_buffer(dev, ring); } diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 526182ed0c6..6af87cd0572 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -94,6 +94,7 @@ struct intel_ring_buffer { u32 offset, u32 length, unsigned flags); #define I915_DISPATCH_SECURE 0x1 +#define I915_DISPATCH_PINNED 0x2 void (*cleanup)(struct intel_ring_buffer *ring); int (*sync_to)(struct intel_ring_buffer *ring, struct intel_ring_buffer *to, -- cgit v1.2.3-70-g09d2