[Intel-gfx] [PATCH 08/25] drm/i915/guc: Add multi-lrc context registration

Matthew Brost
2021-10-14T17:46:21Z

Add multi-lrc context registration H2G. In addition a workqueue and
process descriptor are setup during multi-lrc context registration as
these data structures are needed for multi-lrc submission.

v2:
(John Harrison)
- Move GuC specific fields into sub-struct
- Clean up WQ defines
- Add comment explaining math to derive WQ / PD address
v3:
(John Harrison)
- Add PARENT_SCRATCH_SIZE define
- Update comment explaining multi-lrc register
v4:
(John Harrison)
- Move PARENT_SCRATCH_SIZE to common file

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
drivers/gpu/drm/i915/gt/intel_context.h | 2 +
drivers/gpu/drm/i915/gt/intel_context_types.h | 12 ++
drivers/gpu/drm/i915/gt/intel_lrc.c | 5 +
.../gpu/drm/i915/gt/uc/abi/guc_actions_abi.h | 1 +
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h | 2 -
.../gpu/drm/i915/gt/uc/intel_guc_submission.c | 115 +++++++++++++++++-
6 files changed, 134 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index b63c10a144af..9f0995150a7a 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -44,6 +44,8 @@ void intel_context_free(struct intel_context *ce);
int intel_context_reconfigure_sseu(struct intel_context *ce,
const struct intel_sseu sseu);

+#define PARENT_SCRATCH_SIZE PAGE_SIZE
+
static inline bool intel_context_is_child(struct intel_context *ce)
{
return !!ce->parallel.parent;
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 76dfca57cb45..48decb5ee954 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -239,6 +239,18 @@ struct intel_context {
struct intel_context *parent;
/** @number_children: number of children if parent */
u8 number_children;
+ /** @guc: GuC specific members for parallel submission */
+ struct {
+ /** @wqi_head: head pointer in work queue */
+ u16 wqi_head;
+ /** @wqi_tail: tail pointer in work queue */
+ u16 wqi_tail;
+ /**
+ * @parent_page: page in context state (ce->state) used
+ * by parent for work queue, process descriptor
+ */
+ u8 parent_page;
+ } guc;
} parallel;

#ifdef CONFIG_DRM_I915_SELFTEST
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 3ef9eaf8c50e..56156cf18c41 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -942,6 +942,11 @@ __lrc_alloc_state(struct intel_context *ce, struct intel_engine_cs *engine)
context_size += PAGE_SIZE;
}

+ if (intel_context_is_parent(ce) && intel_engine_uses_guc(engine)) {
+ ce->parallel.guc.parent_page = context_size / PAGE_SIZE;
+ context_size += PARENT_SCRATCH_SIZE;
+ }
+
obj = i915_gem_object_create_lmem(engine->i915, context_size,
I915_BO_ALLOC_PM_VOLATILE);
if (IS_ERR(obj))
diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
index 8ff582222aff..ba10bd374cee 100644
--- a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
+++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
@@ -142,6 +142,7 @@ enum intel_guc_action {
INTEL_GUC_ACTION_REGISTER_COMMAND_TRANSPORT_BUFFER = 0x4505,
INTEL_GUC_ACTION_DEREGISTER_COMMAND_TRANSPORT_BUFFER = 0x4506,
INTEL_GUC_ACTION_DEREGISTER_CONTEXT_DONE = 0x4600,
+ INTEL_GUC_ACTION_REGISTER_CONTEXT_MULTI_LRC = 0x4601,
INTEL_GUC_ACTION_RESET_CLIENT = 0x5507,
INTEL_GUC_ACTION_LIMIT
};
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h
index fa4be13c8854..0eeb2a9feeed 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h
@@ -52,8 +52,6 @@

#define GUC_DOORBELL_INVALID 256

-#define GUC_WQ_SIZE (PAGE_SIZE * 2)
-
/* Work queue item header definitions */
#define WQ_STATUS_ACTIVE 1
#define WQ_STATUS_SUSPENDED 2
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index fd6594bc1b96..d9f5be00e586 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -344,6 +344,46 @@ static inline struct i915_priolist *to_priolist(struct rb_node *rb)
return rb_entry(rb, struct i915_priolist, node);
}

+/*
+ * When using multi-lrc submission a scratch memory area is reserved in the
+ * parent's context state for the process descriptor and work queue. Currently
+ * the scratch area is sized to a page.
+ *
+ * The layout of this scratch area is below:
+ * 0 guc_process_desc
+ * ... unused
+ * PARENT_SCRATCH_SIZE / 2 work queue start
+ * ... work queue
+ * PARENT_SCRATCH_SIZE - 1 work queue end
+ */
+#define WQ_SIZE (PARENT_SCRATCH_SIZE / 2)
+#define WQ_OFFSET (PARENT_SCRATCH_SIZE - WQ_SIZE)
+static u32 __get_process_desc_offset(struct intel_context *ce)
+{
+ GEM_BUG_ON(!ce->parallel.guc.parent_page);
+
+ return ce->parallel.guc.parent_page * PAGE_SIZE;
+}
+
+static u32 __get_wq_offset(struct intel_context *ce)
+{
+ return __get_process_desc_offset(ce) + WQ_OFFSET;
+}
+
+static struct guc_process_desc *
+__get_process_desc(struct intel_context *ce)
+{
+ /*
+ * Need to subtract LRC_STATE_OFFSET here as the
+ * parallel.guc.parent_page is the offset into ce->state while
+ * ce->lrc_reg_reg is ce->state + LRC_STATE_OFFSET.
+ */
+ return (struct guc_process_desc *)
+ (ce->lrc_reg_state +
+ ((__get_process_desc_offset(ce) -
+ LRC_STATE_OFFSET) / sizeof(u32)));
+}
+
static struct guc_lrc_desc *__get_lrc_desc(struct intel_guc *guc, u32 index)
{
struct guc_lrc_desc *base = guc->lrc_desc_pool_vaddr;
@@ -1365,6 +1405,30 @@ static void unpin_guc_id(struct intel_guc *guc, struct intel_context *ce)
spin_unlock_irqrestore(&guc->submission_state.lock, flags);
}

+static int __guc_action_register_multi_lrc(struct intel_guc *guc,
+ struct intel_context *ce,
+ u32 guc_id,
+ u32 offset,
+ bool loop)
+{
+ struct intel_context *child;
+ u32 action[4 + MAX_ENGINE_INSTANCE];
+ int len = 0;
+
+ GEM_BUG_ON(ce->parallel.number_children > MAX_ENGINE_INSTANCE);
+
+ action[len++] = INTEL_GUC_ACTION_REGISTER_CONTEXT_MULTI_LRC;
+ action[len++] = guc_id;
+ action[len++] = ce->parallel.number_children + 1;
+ action[len++] = offset;
+ for_each_child(ce, child) {
+ offset += sizeof(struct guc_lrc_desc);
+ action[len++] = offset;
+ }
+
+ return guc_submission_send_busy_loop(guc, action, len, 0, loop);
+}
+
static int __guc_action_register_context(struct intel_guc *guc,
u32 guc_id,
u32 offset,
@@ -1387,9 +1451,15 @@ static int register_context(struct intel_context *ce, bool loop)
ce->guc_id.id * sizeof(struct guc_lrc_desc);
int ret;

+ GEM_BUG_ON(intel_context_is_child(ce));
trace_intel_context_register(ce);

- ret = __guc_action_register_context(guc, ce->guc_id.id, offset, loop);
+ if (intel_context_is_parent(ce))
+ ret = __guc_action_register_multi_lrc(guc, ce, ce->guc_id.id,
+ offset, loop);
+ else
+ ret = __guc_action_register_context(guc, ce->guc_id.id, offset,
+ loop);
if (likely(!ret)) {
unsigned long flags;

@@ -1418,6 +1488,7 @@ static int deregister_context(struct intel_context *ce, u32 guc_id)
{
struct intel_guc *guc = ce_to_guc(ce);

+ GEM_BUG_ON(intel_context_is_child(ce));
trace_intel_context_deregister(ce);

return __guc_action_deregister_context(guc, guc_id);
@@ -1445,6 +1516,7 @@ static int guc_lrc_desc_pin(struct intel_context *ce, bool loop)
struct guc_lrc_desc *desc;
bool context_registered;
intel_wakeref_t wakeref;
+ struct intel_context *child;
int ret = 0;

GEM_BUG_ON(!engine->mask);
@@ -1470,6 +1542,41 @@ static int guc_lrc_desc_pin(struct intel_context *ce, bool loop)
desc->context_flags = CONTEXT_REGISTRATION_FLAG_KMD;
guc_context_policy_init(engine, desc);

+ /*
+ * If context is a parent, we need to register a process descriptor
+ * describing a work queue and register all child contexts.
+ */
+ if (intel_context_is_parent(ce)) {
+ struct guc_process_desc *pdesc;
+
+ ce->parallel.guc.wqi_tail = 0;
+ ce->parallel.guc.wqi_head = 0;
+
+ desc->process_desc = i915_ggtt_offset(ce->state) +
+ __get_process_desc_offset(ce);
+ desc->wq_addr = i915_ggtt_offset(ce->state) +
+ __get_wq_offset(ce);
+ desc->wq_size = WQ_SIZE;
+
+ pdesc = __get_process_desc(ce);
+ memset(pdesc, 0, sizeof(*(pdesc)));
+ pdesc->stage_id = ce->guc_id.id;
+ pdesc->wq_base_addr = desc->wq_addr;
+ pdesc->wq_size_bytes = desc->wq_size;
+ pdesc->wq_status = WQ_STATUS_ACTIVE;
+
+ for_each_child(ce, child) {
+ desc = __get_lrc_desc(guc, child->guc_id.id);
+
+ desc->engine_class =
+ engine_class_to_guc_class(engine->class);
+ desc->hw_context_desc = child->lrc.lrca;
+ desc->priority = ce->guc_state.prio;
+ desc->context_flags = CONTEXT_REGISTRATION_FLAG_KMD;
+ guc_context_policy_init(engine, desc);
+ }
+ }
+
/*
* The context_lookup xarray is used to determine if the hardware
* context is currently registered. There are two cases in which it
@@ -2804,6 +2911,12 @@ g2h_context_lookup(struct intel_guc *guc, u32 desc_idx)
return NULL;
}

+ if (unlikely(intel_context_is_child(ce))) {
+ drm_err(&guc_to_gt(guc)->i915->drm,
+ "Context is child, desc_idx %u", desc_idx);
+ return NULL;
+ }
+
return ce;
}

--
2.32.0