From 86e06cc0c0ecf3fdfe04ff48fccb34891767d514 Mon Sep 17 00:00:00 2001 From: Dave Gordon Date: Tue, 19 Apr 2016 16:08:36 +0100 Subject: [PATCH] drm/i915/guc: local optimisations and updating comments Tidying up guc_init_proc_desc() and adding commentary to the client structure after the recent change in GuC page mapping strategy. Signed-off-by: Dave Gordon Signed-off-by: Tvrtko Ursulin Link: http://patchwork.freedesktop.org/patch/msgid/1461078516-28678-1-git-send-email-david.s.gordon@intel.com Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_guc_submission.c | 38 ++++++++++------------ drivers/gpu/drm/i915/intel_guc.h | 23 +++++++++++++ 2 files changed, 41 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index 4718b7a51f5d..d40c13fb6643 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -358,12 +358,14 @@ static void guc_init_proc_desc(struct intel_guc *guc, static void guc_init_ctx_desc(struct intel_guc *guc, struct i915_guc_client *client) { + struct drm_i915_gem_object *client_obj = client->client_obj; struct drm_i915_private *dev_priv = guc_to_i915(guc); struct intel_engine_cs *engine; struct intel_context *ctx = client->owner; struct guc_context_desc desc; struct sg_table *sg; enum intel_engine_id id; + u32 gfx_addr; memset(&desc, 0, sizeof(desc)); @@ -392,16 +394,17 @@ static void guc_init_ctx_desc(struct intel_guc *guc, lrc->context_desc = (u32)ctx_desc; /* The state page is after PPHWSP */ - lrc->ring_lcra = i915_gem_obj_ggtt_offset(obj) + - LRC_STATE_PN * PAGE_SIZE; + gfx_addr = i915_gem_obj_ggtt_offset(obj); + lrc->ring_lcra = gfx_addr + LRC_STATE_PN * PAGE_SIZE; lrc->context_id = (client->ctx_index << GUC_ELC_CTXID_OFFSET) | (engine->guc_id << GUC_ELC_ENGINE_OFFSET); obj = ctx->engine[id].ringbuf->obj; + gfx_addr = i915_gem_obj_ggtt_offset(obj); - lrc->ring_begin = i915_gem_obj_ggtt_offset(obj); - lrc->ring_end = lrc->ring_begin + obj->base.size - 1; - lrc->ring_next_free_location = lrc->ring_begin; + lrc->ring_begin = gfx_addr; + lrc->ring_end = gfx_addr + obj->base.size - 1; + lrc->ring_next_free_location = gfx_addr; lrc->ring_current_tail_pointer_value = 0; desc.engines_used |= (1 << engine->guc_id); @@ -410,22 +413,17 @@ static void guc_init_ctx_desc(struct intel_guc *guc, WARN_ON(desc.engines_used == 0); /* - * The CPU address is only needed at certain points, so kmap_atomic on - * demand instead of storing it in the ctx descriptor. - * XXX: May make debug easier to have it mapped + * The doorbell, process descriptor, and workqueue are all parts + * of the client object, which the GuC will reference via the GGTT */ - desc.db_trigger_cpu = 0; - desc.db_trigger_uk = client->doorbell_offset + - i915_gem_obj_ggtt_offset(client->client_obj); - desc.db_trigger_phy = client->doorbell_offset + - sg_dma_address(client->client_obj->pages->sgl); - - desc.process_desc = client->proc_desc_offset + - i915_gem_obj_ggtt_offset(client->client_obj); - - desc.wq_addr = client->wq_offset + - i915_gem_obj_ggtt_offset(client->client_obj); - + gfx_addr = i915_gem_obj_ggtt_offset(client_obj); + desc.db_trigger_phy = sg_dma_address(client_obj->pages->sgl) + + client->doorbell_offset; + desc.db_trigger_cpu = (uintptr_t)client->client_base + + client->doorbell_offset; + desc.db_trigger_uk = gfx_addr + client->doorbell_offset; + desc.process_desc = gfx_addr + client->proc_desc_offset; + desc.wq_addr = gfx_addr + client->wq_offset; desc.wq_size = client->wq_size; /* diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h index 19ca5933a090..9d79c4c3e256 100644 --- a/drivers/gpu/drm/i915/intel_guc.h +++ b/drivers/gpu/drm/i915/intel_guc.h @@ -29,6 +29,29 @@ struct drm_i915_gem_request; +/* + * This structure primarily describes the GEM object shared with the GuC. + * The GEM object is held for the entire lifetime of our interaction with + * the GuC, being allocated before the GuC is loaded with its firmware. + * Because there's no way to update the address used by the GuC after + * initialisation, the shared object must stay pinned into the GGTT as + * long as the GuC is in use. We also keep the first page (only) mapped + * into kernel address space, as it includes shared data that must be + * updated on every request submission. + * + * The single GEM object described here is actually made up of several + * separate areas, as far as the GuC is concerned. The first page (kept + * kmap'd) includes the "process decriptor" which holds sequence data for + * the doorbell, and one cacheline which actually *is* the doorbell; a + * write to this will "ring the doorbell" (i.e. send an interrupt to the + * GuC). The subsequent pages of the client object constitute the work + * queue (a circular array of work items), again described in the process + * descriptor. Work queue pages are mapped momentarily as required. + * + * Finally, we also keep a few statistics here, including the number of + * submissions to each engine, and a record of the last submission failure + * (if any). + */ struct i915_guc_client { struct drm_i915_gem_object *client_obj; void *client_base; /* first page (only) of above */ -- 2.20.1