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author | Oscar Mateo | 2017-03-22 18:39:50 +0100 |
---|---|---|
committer | Joonas Lahtinen | 2017-03-23 13:58:18 +0100 |
commit | 0d7681261453e6f10e0a98e7b744fe4085743291 (patch) | |
tree | 3f067e09918afe64775cfda57e3c429d75378d3d /drivers/gpu/drm/i915/i915_guc_submission.c | |
parent | drm/i915/guc: Make intel_guc_send a function pointer (diff) | |
download | kernel-qcow2-linux-0d7681261453e6f10e0a98e7b744fe4085743291.tar.gz kernel-qcow2-linux-0d7681261453e6f10e0a98e7b744fe4085743291.tar.xz kernel-qcow2-linux-0d7681261453e6f10e0a98e7b744fe4085743291.zip |
drm/i915/guc: Improve the GuC documentation & comments about proxy submissions
While at it, fix a typo (s/ring_lcra/ring_lrca) and improve the naming of one
firware interface field (s/ring_tail/submit_element_info, since it can contain
more than just the ring tail).
No change in functionality.
v2:
- Remove reference to "unique user" of the GuC (Daniele)
- Keep mention to renaming from "GuC context" to "client" (Daniele)
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_guc_submission.c')
-rw-r--r-- | drivers/gpu/drm/i915/i915_guc_submission.c | 42 |
1 files changed, 27 insertions, 15 deletions
diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index ab91dac15b5b..e98cb743090f 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -30,16 +30,25 @@ /** * DOC: GuC-based command submission * - * i915_guc_client: - * We use the term client to avoid confusion with contexts. A i915_guc_client is - * equivalent to GuC object guc_context_desc. This context descriptor is - * allocated from a pool of 1024 entries. Kernel driver will allocate doorbell - * and workqueue for it. Also the process descriptor (guc_process_desc), which - * is mapped to client space. So the client can write Work Item then ring the - * doorbell. + * GuC client: + * A i915_guc_client refers to a submission path through GuC. Currently, there + * is only one of these (the execbuf_client) and this one is charged with all + * submissions to the GuC. This struct is the owner of a doorbell, a process + * descriptor and a workqueue (all of them inside a single gem object that + * contains all required pages for these elements). * - * To simplify the implementation, we allocate one gem object that contains all - * pages for doorbell, process descriptor and workqueue. + * GuC context descriptor: + * During initialization, the driver allocates a static pool of 1024 such + * descriptors, and shares them with the GuC. + * Currently, there exists a 1:1 mapping between a i915_guc_client and a + * guc_context_desc (via the client's context_index), so effectively only + * one guc_context_desc gets used. This context descriptor lets the GuC know + * about the doorbell, workqueue and process descriptor. Theoretically, it also + * lets the GuC know about our HW contexts (Context ID, etc...), but we actually + * employ a kind of submission where the GuC uses the LRCA sent via the work + * item instead (the single guc_context_desc associated to execbuf client + * contains information about the default kernel context only, but this is + * essentially unused). This is called a "proxy" submission. * * The Scratch registers: * There are 16 MMIO-based registers start from 0xC180. The kernel driver writes @@ -308,10 +317,17 @@ static void guc_ctx_desc_init(struct intel_guc *guc, if (!ce->state) break; /* XXX: continue? */ + /* + * XXX: When this is a GUC_CTX_DESC_ATTR_KERNEL client (proxy + * submission or, in other words, not using a direct submission + * model) the KMD's LRCA is not used for any work submission. + * Instead, the GuC uses the LRCA of the user mode context (see + * guc_wq_item_append below). + */ lrc->context_desc = lower_32_bits(ce->lrc_desc); /* The state page is after PPHWSP */ - lrc->ring_lcra = + lrc->ring_lrca = guc_ggtt_offset(ce->state) + LRC_STATE_PN * PAGE_SIZE; lrc->context_id = (client->ctx_index << GUC_ELC_CTXID_OFFSET) | (guc_engine_id << GUC_ELC_ENGINE_OFFSET); @@ -341,10 +357,6 @@ static void guc_ctx_desc_init(struct intel_guc *guc, desc->wq_addr = gfx_addr + client->wq_offset; desc->wq_size = client->wq_size; - /* - * XXX: Take LRCs from an existing context if this is not an - * IsKMDCreatedContext client - */ desc->desc_private = (uintptr_t)client; } @@ -468,7 +480,7 @@ static void guc_wq_item_append(struct i915_guc_client *client, /* The GuC wants only the low-order word of the context descriptor */ wqi->context_desc = (u32)intel_lr_context_descriptor(rq->ctx, engine); - wqi->ring_tail = tail << WQ_RING_TAIL_SHIFT; + wqi->submit_element_info = tail << WQ_RING_TAIL_SHIFT; wqi->fence_id = rq->global_seqno; } |