#define __EXEC_OBJECT_HAS_FENCE (1<<30)
#define __EXEC_OBJECT_NEEDS_MAP (1<<29)
#define __EXEC_OBJECT_NEEDS_BIAS (1<<28)
-#define __EXEC_OBJECT_PURGEABLE (1<<27)
#define BATCH_OFFSET_BIAS (256*1024)
if (entry->flags & __EXEC_OBJECT_HAS_PIN)
vma->pin_count--;
- if (entry->flags & __EXEC_OBJECT_PURGEABLE)
- obj->madv = I915_MADV_DONTNEED;
-
- entry->flags &= ~(__EXEC_OBJECT_HAS_FENCE |
- __EXEC_OBJECT_HAS_PIN |
- __EXEC_OBJECT_PURGEABLE);
+ entry->flags &= ~(__EXEC_OBJECT_HAS_FENCE | __EXEC_OBJECT_HAS_PIN);
}
static void eb_destroy(struct eb_vmas *eb)
* pipe_control writes because the gpu doesn't properly redirect them
* through the ppgtt for non_secure batchbuffers. */
if (unlikely(IS_GEN6(dev) &&
- reloc->write_domain == I915_GEM_DOMAIN_INSTRUCTION &&
- !(target_vma->bound & GLOBAL_BIND))) {
+ reloc->write_domain == I915_GEM_DOMAIN_INSTRUCTION)) {
ret = i915_vma_bind(target_vma, target_i915_obj->cache_level,
- GLOBAL_BIND);
+ PIN_GLOBAL);
if (WARN_ONCE(ret, "Unexpected failure to bind target VMA!"))
return ret;
}
uint64_t flags;
int ret;
- flags = 0;
+ flags = PIN_USER;
+ if (entry->flags & EXEC_OBJECT_NEEDS_GTT)
+ flags |= PIN_GLOBAL;
+
if (!drm_mm_node_allocated(&vma->node)) {
+ /* Wa32bitGeneralStateOffset & Wa32bitInstructionBaseOffset,
+ * limit address to the first 4GBs for unflagged objects.
+ */
+ if ((entry->flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS) == 0)
+ flags |= PIN_ZONE_4G;
if (entry->flags & __EXEC_OBJECT_NEEDS_MAP)
flags |= PIN_GLOBAL | PIN_MAPPABLE;
- if (entry->flags & EXEC_OBJECT_NEEDS_GTT)
- flags |= PIN_GLOBAL;
if (entry->flags & __EXEC_OBJECT_NEEDS_BIAS)
flags |= BATCH_OFFSET_BIAS | PIN_OFFSET_BIAS;
+ if ((flags & PIN_MAPPABLE) == 0)
+ flags |= PIN_HIGH;
}
ret = i915_gem_object_pin(obj, vma->vm, entry->alignment, flags);
only_mappable_for_reloc(entry->flags))
ret = i915_gem_object_pin(obj, vma->vm,
entry->alignment,
- flags & ~(PIN_GLOBAL | PIN_MAPPABLE));
+ flags & ~PIN_MAPPABLE);
if (ret)
return ret;
if (entry->flags & __EXEC_OBJECT_NEEDS_MAP && !obj->map_and_fenceable)
return !only_mappable_for_reloc(entry->flags);
+ if ((entry->flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS) == 0 &&
+ (vma->node.start + vma->node.size - 1) >> 32)
+ return true;
+
return false;
}
static int
i915_gem_execbuffer_reserve(struct intel_engine_cs *ring,
struct list_head *vmas,
+ struct intel_context *ctx,
bool *need_relocs)
{
struct drm_i915_gem_object *obj;
obj = vma->obj;
entry = vma->exec_entry;
+ if (ctx->flags & CONTEXT_NO_ZEROMAP)
+ entry->flags |= __EXEC_OBJECT_NEEDS_BIAS;
+
if (!has_fenced_gpu_access)
entry->flags &= ~EXEC_OBJECT_NEEDS_FENCE;
need_fence =
struct drm_file *file,
struct intel_engine_cs *ring,
struct eb_vmas *eb,
- struct drm_i915_gem_exec_object2 *exec)
+ struct drm_i915_gem_exec_object2 *exec,
+ struct intel_context *ctx)
{
struct drm_i915_gem_relocation_entry *reloc;
struct i915_address_space *vm;
goto err;
need_relocs = (args->flags & I915_EXEC_NO_RELOC) == 0;
- ret = i915_gem_execbuffer_reserve(ring, &eb->vmas, &need_relocs);
+ ret = i915_gem_execbuffer_reserve(ring, &eb->vmas, ctx, &need_relocs);
if (ret)
goto err;
}
static int
-i915_gem_execbuffer_move_to_gpu(struct intel_engine_cs *ring,
+i915_gem_execbuffer_move_to_gpu(struct drm_i915_gem_request *req,
struct list_head *vmas)
{
+ const unsigned other_rings = ~intel_ring_flag(req->ring);
struct i915_vma *vma;
uint32_t flush_domains = 0;
bool flush_chipset = false;
list_for_each_entry(vma, vmas, exec_list) {
struct drm_i915_gem_object *obj = vma->obj;
- ret = i915_gem_object_sync(obj, ring);
- if (ret)
- return ret;
+
+ if (obj->active & other_rings) {
+ ret = i915_gem_object_sync(obj, req->ring, &req);
+ if (ret)
+ return ret;
+ }
if (obj->base.write_domain & I915_GEM_DOMAIN_CPU)
flush_chipset |= i915_gem_clflush_object(obj, false);
}
if (flush_chipset)
- i915_gem_chipset_flush(ring->dev);
+ i915_gem_chipset_flush(req->ring->dev);
if (flush_domains & I915_GEM_DOMAIN_GTT)
wmb();
/* Unconditionally invalidate gpu caches and ensure that we do flush
* any residual writes from the previous batch.
*/
- return intel_ring_invalidate_all_caches(ring);
+ return intel_ring_invalidate_all_caches(req);
}
static bool
if (exec->flags & __I915_EXEC_UNKNOWN_FLAGS)
return false;
- return ((exec->batch_start_offset | exec->batch_len) & 0x7) == 0;
+ /* Kernel clipping was a DRI1 misfeature */
+ if (exec->num_cliprects || exec->cliprects_ptr)
+ return false;
+
+ if (exec->DR4 == 0xffffffff) {
+ DRM_DEBUG("UXA submitting garbage DR4, fixing up\n");
+ exec->DR4 = 0;
+ }
+ if (exec->DR1 || exec->DR4)
+ return false;
+
+ if ((exec->batch_start_offset | exec->batch_len) & 0x7)
+ return false;
+
+ return true;
}
static int
if (exec[i].flags & invalid_flags)
return -EINVAL;
+ if (exec[i].alignment && !is_power_of_2(exec[i].alignment))
+ return -EINVAL;
+
/* First check for malicious input causing overflow in
* the worst case where we need to allocate the entire
* relocation tree as a single array.
}
if (i915.enable_execlists && !ctx->engine[ring->id].state) {
- int ret = intel_lr_context_deferred_create(ctx, ring);
+ int ret = intel_lr_context_deferred_alloc(ctx, ring);
if (ret) {
DRM_DEBUG("Could not create LRC %u: %d\n", ctx_id, ret);
return ERR_PTR(ret);
void
i915_gem_execbuffer_move_to_active(struct list_head *vmas,
- struct intel_engine_cs *ring)
+ struct drm_i915_gem_request *req)
{
- struct drm_i915_gem_request *req = intel_ring_get_request(ring);
+ struct intel_engine_cs *ring = i915_gem_request_get_ring(req);
struct i915_vma *vma;
list_for_each_entry(vma, vmas, exec_list) {
obj->base.pending_read_domains |= obj->base.read_domains;
obj->base.read_domains = obj->base.pending_read_domains;
- i915_vma_move_to_active(vma, ring);
+ i915_vma_move_to_active(vma, req);
if (obj->base.write_domain) {
i915_gem_request_assign(&obj->last_write_req, req);
- intel_fb_obj_invalidate(obj, ring, ORIGIN_CS);
+ intel_fb_obj_invalidate(obj, ORIGIN_CS);
/* update for the implicit flush after a batch */
obj->base.write_domain &= ~I915_GEM_GPU_DOMAINS;
}
void
-i915_gem_execbuffer_retire_commands(struct drm_device *dev,
- struct drm_file *file,
- struct intel_engine_cs *ring,
- struct drm_i915_gem_object *obj)
+i915_gem_execbuffer_retire_commands(struct i915_execbuffer_params *params)
{
/* Unconditionally force add_request to emit a full flush. */
- ring->gpu_caches_dirty = true;
+ params->ring->gpu_caches_dirty = true;
/* Add a breadcrumb for the completion of the batch buffer */
- (void)__i915_add_request(ring, file, obj);
+ __i915_add_request(params->request, params->batch_obj, true);
}
static int
i915_reset_gen7_sol_offsets(struct drm_device *dev,
- struct intel_engine_cs *ring)
+ struct drm_i915_gem_request *req)
{
+ struct intel_engine_cs *ring = req->ring;
struct drm_i915_private *dev_priv = dev->dev_private;
int ret, i;
return -EINVAL;
}
- ret = intel_ring_begin(ring, 4 * 3);
+ ret = intel_ring_begin(req, 4 * 3);
if (ret)
return ret;
return 0;
}
-static int
-i915_emit_box(struct intel_engine_cs *ring,
- struct drm_clip_rect *box,
- int DR1, int DR4)
-{
- int ret;
-
- if (box->y2 <= box->y1 || box->x2 <= box->x1 ||
- box->y2 <= 0 || box->x2 <= 0) {
- DRM_ERROR("Bad box %d,%d..%d,%d\n",
- box->x1, box->y1, box->x2, box->y2);
- return -EINVAL;
- }
-
- if (INTEL_INFO(ring->dev)->gen >= 4) {
- ret = intel_ring_begin(ring, 4);
- if (ret)
- return ret;
-
- intel_ring_emit(ring, GFX_OP_DRAWRECT_INFO_I965);
- intel_ring_emit(ring, (box->x1 & 0xffff) | box->y1 << 16);
- intel_ring_emit(ring, ((box->x2 - 1) & 0xffff) | (box->y2 - 1) << 16);
- intel_ring_emit(ring, DR4);
- } else {
- ret = intel_ring_begin(ring, 6);
- if (ret)
- return ret;
-
- intel_ring_emit(ring, GFX_OP_DRAWRECT_INFO);
- intel_ring_emit(ring, DR1);
- intel_ring_emit(ring, (box->x1 & 0xffff) | box->y1 << 16);
- intel_ring_emit(ring, ((box->x2 - 1) & 0xffff) | (box->y2 - 1) << 16);
- intel_ring_emit(ring, DR4);
- intel_ring_emit(ring, 0);
- }
- intel_ring_advance(ring);
-
- return 0;
-}
-
static struct drm_i915_gem_object*
i915_gem_execbuffer_parse(struct intel_engine_cs *ring,
struct drm_i915_gem_exec_object2 *shadow_exec_entry,
u32 batch_len,
bool is_master)
{
- struct drm_i915_private *dev_priv = to_i915(batch_obj->base.dev);
struct drm_i915_gem_object *shadow_batch_obj;
struct i915_vma *vma;
int ret;
- shadow_batch_obj = i915_gem_batch_pool_get(&dev_priv->mm.batch_pool,
+ shadow_batch_obj = i915_gem_batch_pool_get(&ring->batch_pool,
PAGE_ALIGN(batch_len));
if (IS_ERR(shadow_batch_obj))
return shadow_batch_obj;
if (ret)
goto err;
+ i915_gem_object_unpin_pages(shadow_batch_obj);
+
memset(shadow_exec_entry, 0, sizeof(*shadow_exec_entry));
vma = i915_gem_obj_to_ggtt(shadow_batch_obj);
vma->exec_entry = shadow_exec_entry;
- vma->exec_entry->flags = __EXEC_OBJECT_PURGEABLE | __EXEC_OBJECT_HAS_PIN;
+ vma->exec_entry->flags = __EXEC_OBJECT_HAS_PIN;
drm_gem_object_reference(&shadow_batch_obj->base);
list_add_tail(&vma->exec_list, &eb->vmas);
return shadow_batch_obj;
err:
+ i915_gem_object_unpin_pages(shadow_batch_obj);
if (ret == -EACCES) /* unhandled chained batch */
return batch_obj;
else
}
int
-i915_gem_ringbuffer_submission(struct drm_device *dev, struct drm_file *file,
- struct intel_engine_cs *ring,
- struct intel_context *ctx,
+i915_gem_ringbuffer_submission(struct i915_execbuffer_params *params,
struct drm_i915_gem_execbuffer2 *args,
- struct list_head *vmas,
- struct drm_i915_gem_object *batch_obj,
- u64 exec_start, u32 dispatch_flags)
+ struct list_head *vmas)
{
- struct drm_clip_rect *cliprects = NULL;
+ struct drm_device *dev = params->dev;
+ struct intel_engine_cs *ring = params->ring;
struct drm_i915_private *dev_priv = dev->dev_private;
- u64 exec_len;
+ u64 exec_start, exec_len;
int instp_mode;
u32 instp_mask;
- int i, ret = 0;
-
- if (args->num_cliprects != 0) {
- if (ring != &dev_priv->ring[RCS]) {
- DRM_DEBUG("clip rectangles are only valid with the render ring\n");
- return -EINVAL;
- }
-
- if (INTEL_INFO(dev)->gen >= 5) {
- DRM_DEBUG("clip rectangles are only valid on pre-gen5\n");
- return -EINVAL;
- }
-
- if (args->num_cliprects > UINT_MAX / sizeof(*cliprects)) {
- DRM_DEBUG("execbuf with %u cliprects\n",
- args->num_cliprects);
- return -EINVAL;
- }
-
- cliprects = kcalloc(args->num_cliprects,
- sizeof(*cliprects),
- GFP_KERNEL);
- if (cliprects == NULL) {
- ret = -ENOMEM;
- goto error;
- }
-
- if (copy_from_user(cliprects,
- to_user_ptr(args->cliprects_ptr),
- sizeof(*cliprects)*args->num_cliprects)) {
- ret = -EFAULT;
- goto error;
- }
- } else {
- if (args->DR4 == 0xffffffff) {
- DRM_DEBUG("UXA submitting garbage DR4, fixing up\n");
- args->DR4 = 0;
- }
-
- if (args->DR1 || args->DR4 || args->cliprects_ptr) {
- DRM_DEBUG("0 cliprects but dirt in cliprects fields\n");
- return -EINVAL;
- }
- }
+ int ret;
- ret = i915_gem_execbuffer_move_to_gpu(ring, vmas);
+ ret = i915_gem_execbuffer_move_to_gpu(params->request, vmas);
if (ret)
- goto error;
+ return ret;
- ret = i915_switch_context(ring, ctx);
+ ret = i915_switch_context(params->request);
if (ret)
- goto error;
+ return ret;
- if (ctx->ppgtt)
- WARN(ctx->ppgtt->pd_dirty_rings & (1<<ring->id),
- "%s didn't clear reload\n", ring->name);
- else if (dev_priv->mm.aliasing_ppgtt)
- WARN(dev_priv->mm.aliasing_ppgtt->pd_dirty_rings &
- (1<<ring->id), "%s didn't clear reload\n", ring->name);
+ WARN(params->ctx->ppgtt && params->ctx->ppgtt->pd_dirty_rings & (1<<ring->id),
+ "%s didn't clear reload\n", ring->name);
instp_mode = args->flags & I915_EXEC_CONSTANTS_MASK;
instp_mask = I915_EXEC_CONSTANTS_MASK;
case I915_EXEC_CONSTANTS_REL_SURFACE:
if (instp_mode != 0 && ring != &dev_priv->ring[RCS]) {
DRM_DEBUG("non-0 rel constants mode on non-RCS\n");
- ret = -EINVAL;
- goto error;
+ return -EINVAL;
}
if (instp_mode != dev_priv->relative_constants_mode) {
if (INTEL_INFO(dev)->gen < 4) {
DRM_DEBUG("no rel constants on pre-gen4\n");
- ret = -EINVAL;
- goto error;
+ return -EINVAL;
}
if (INTEL_INFO(dev)->gen > 5 &&
instp_mode == I915_EXEC_CONSTANTS_REL_SURFACE) {
DRM_DEBUG("rel surface constants mode invalid on gen5+\n");
- ret = -EINVAL;
- goto error;
+ return -EINVAL;
}
/* The HW changed the meaning on this bit on gen6 */
break;
default:
DRM_DEBUG("execbuf with unknown constants: %d\n", instp_mode);
- ret = -EINVAL;
- goto error;
+ return -EINVAL;
}
if (ring == &dev_priv->ring[RCS] &&
- instp_mode != dev_priv->relative_constants_mode) {
- ret = intel_ring_begin(ring, 4);
+ instp_mode != dev_priv->relative_constants_mode) {
+ ret = intel_ring_begin(params->request, 4);
if (ret)
- goto error;
+ return ret;
intel_ring_emit(ring, MI_NOOP);
intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
}
if (args->flags & I915_EXEC_GEN7_SOL_RESET) {
- ret = i915_reset_gen7_sol_offsets(dev, ring);
+ ret = i915_reset_gen7_sol_offsets(dev, params->request);
if (ret)
- goto error;
+ return ret;
}
- exec_len = args->batch_len;
- if (cliprects) {
- for (i = 0; i < args->num_cliprects; i++) {
- ret = i915_emit_box(ring, &cliprects[i],
- args->DR1, args->DR4);
- if (ret)
- goto error;
+ exec_len = args->batch_len;
+ exec_start = params->batch_obj_vm_offset +
+ params->args_batch_start_offset;
- ret = ring->dispatch_execbuffer(ring,
- exec_start, exec_len,
- dispatch_flags);
- if (ret)
- goto error;
- }
- } else {
- ret = ring->dispatch_execbuffer(ring,
- exec_start, exec_len,
- dispatch_flags);
- if (ret)
- return ret;
- }
+ ret = ring->dispatch_execbuffer(params->request,
+ exec_start, exec_len,
+ params->dispatch_flags);
+ if (ret)
+ return ret;
#ifndef CONFIG_PREEMPT_RT_BASE
- trace_i915_gem_ring_dispatch(intel_ring_get_request(ring), dispatch_flags);
+ trace_i915_gem_ring_dispatch(params->request, params->dispatch_flags);
#endif
- i915_gem_execbuffer_move_to_active(vmas, ring);
- i915_gem_execbuffer_retire_commands(dev, file, ring, batch_obj);
+ i915_gem_execbuffer_move_to_active(vmas, params->request);
+ i915_gem_execbuffer_retire_commands(params);
-error:
- kfree(cliprects);
- return ret;
+ return 0;
}
/**
struct intel_engine_cs *ring;
struct intel_context *ctx;
struct i915_address_space *vm;
+ struct i915_execbuffer_params params_master; /* XXX: will be removed later */
+ struct i915_execbuffer_params *params = ¶ms_master;
const u32 ctx_id = i915_execbuffer2_get_context_id(*args);
- u64 exec_start = args->batch_start_offset;
u32 dispatch_flags;
int ret;
bool need_relocs;
return -EINVAL;
}
+ if (args->flags & I915_EXEC_RESOURCE_STREAMER) {
+ if (!HAS_RESOURCE_STREAMER(dev)) {
+ DRM_DEBUG("RS is only allowed for Haswell, Gen8 and above\n");
+ return -EINVAL;
+ }
+ if (ring->id != RCS) {
+ DRM_DEBUG("RS is not available on %s\n",
+ ring->name);
+ return -EINVAL;
+ }
+
+ dispatch_flags |= I915_DISPATCH_RS;
+ }
+
intel_runtime_pm_get(dev_priv);
ret = i915_mutex_lock_interruptible(dev);
else
vm = &dev_priv->gtt.base;
+ memset(¶ms_master, 0x00, sizeof(params_master));
+
eb = eb_create(args);
if (eb == NULL) {
i915_gem_context_unreference(ctx);
/* Move the objects en-masse into the GTT, evicting if necessary. */
need_relocs = (args->flags & I915_EXEC_NO_RELOC) == 0;
- ret = i915_gem_execbuffer_reserve(ring, &eb->vmas, &need_relocs);
+ ret = i915_gem_execbuffer_reserve(ring, &eb->vmas, ctx, &need_relocs);
if (ret)
goto err;
if (ret) {
if (ret == -EFAULT) {
ret = i915_gem_execbuffer_relocate_slow(dev, args, file, ring,
- eb, exec);
+ eb, exec, ctx);
BUG_ON(!mutex_is_locked(&dev->struct_mutex));
}
if (ret)
goto err;
}
+ params->args_batch_start_offset = args->batch_start_offset;
if (i915_needs_cmd_parser(ring) && args->batch_len) {
- batch_obj = i915_gem_execbuffer_parse(ring,
+ struct drm_i915_gem_object *parsed_batch_obj;
+
+ parsed_batch_obj = i915_gem_execbuffer_parse(ring,
&shadow_exec_entry,
eb,
batch_obj,
args->batch_start_offset,
args->batch_len,
file->is_master);
- if (IS_ERR(batch_obj)) {
- ret = PTR_ERR(batch_obj);
+ if (IS_ERR(parsed_batch_obj)) {
+ ret = PTR_ERR(parsed_batch_obj);
goto err;
}
/*
- * Set the DISPATCH_SECURE bit to remove the NON_SECURE
- * bit from MI_BATCH_BUFFER_START commands issued in the
- * dispatch_execbuffer implementations. We specifically
- * don't want that set when the command parser is
- * enabled.
- *
- * FIXME: with aliasing ppgtt, buffers that should only
- * be in ggtt still end up in the aliasing ppgtt. remove
- * this check when that is fixed.
+ * parsed_batch_obj == batch_obj means batch not fully parsed:
+ * Accept, but don't promote to secure.
*/
- if (USES_FULL_PPGTT(dev))
- dispatch_flags |= I915_DISPATCH_SECURE;
- exec_start = 0;
+ if (parsed_batch_obj != batch_obj) {
+ /*
+ * Batch parsed and accepted:
+ *
+ * Set the DISPATCH_SECURE bit to remove the NON_SECURE
+ * bit from MI_BATCH_BUFFER_START commands issued in
+ * the dispatch_execbuffer implementations. We
+ * specifically don't want that set on batches the
+ * command parser has accepted.
+ */
+ dispatch_flags |= I915_DISPATCH_SECURE;
+ params->args_batch_start_offset = 0;
+ batch_obj = parsed_batch_obj;
+ }
}
batch_obj->base.pending_read_domains |= I915_GEM_DOMAIN_COMMAND;
if (ret)
goto err;
- exec_start += i915_gem_obj_ggtt_offset(batch_obj);
+ params->batch_obj_vm_offset = i915_gem_obj_ggtt_offset(batch_obj);
} else
- exec_start += i915_gem_obj_offset(batch_obj, vm);
+ params->batch_obj_vm_offset = i915_gem_obj_offset(batch_obj, vm);
- ret = dev_priv->gt.do_execbuf(dev, file, ring, ctx, args,
- &eb->vmas, batch_obj, exec_start,
- dispatch_flags);
+ /* Allocate a request for this batch buffer nice and early. */
+ ret = i915_gem_request_alloc(ring, ctx, ¶ms->request);
+ if (ret)
+ goto err_batch_unpin;
+
+ ret = i915_gem_request_add_to_client(params->request, file);
+ if (ret)
+ goto err_batch_unpin;
+ /*
+ * Save assorted stuff away to pass through to *_submission().
+ * NB: This data should be 'persistent' and not local as it will
+ * kept around beyond the duration of the IOCTL once the GPU
+ * scheduler arrives.
+ */
+ params->dev = dev;
+ params->file = file;
+ params->ring = ring;
+ params->dispatch_flags = dispatch_flags;
+ params->batch_obj = batch_obj;
+ params->ctx = ctx;
+
+ ret = dev_priv->gt.execbuf_submit(params, args, &eb->vmas);
+
+err_batch_unpin:
/*
* FIXME: We crucially rely upon the active tracking for the (ppgtt)
* batch vma for correctness. For less ugly and less fragility this
*/
if (dispatch_flags & I915_DISPATCH_SECURE)
i915_gem_object_ggtt_unpin(batch_obj);
+
err:
/* the request owns the ref now */
i915_gem_context_unreference(ctx);
eb_destroy(eb);
+ /*
+ * If the request was created but not successfully submitted then it
+ * must be freed again. If it was submitted then it is being tracked
+ * on the active request list and no clean up is required here.
+ */
+ if (ret && params->request)
+ i915_gem_request_cancel(params->request);
+
mutex_unlock(&dev->struct_mutex);
pre_mutex_err:
Code Review / kvmfornfv.git / blobdiff