[Intel-gfx] [RFC 44/60] drm/i915: allocate context from LMEM

[Matthew Auld]

Based on a patch from Michel Thierry.

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
---
 drivers/gpu/drm/i915/gt/intel_lrc.c | 31 ++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index fbcfeaed6441..c6528c8f9b2e 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -133,6 +133,8 @@
  */
 #include <linux/interrupt.h>
 
+#include "gem/i915_gem_lmem.h"
+
 #include "i915_drv.h"
 #include "i915_perf.h"
 #include "i915_trace.h"
@@ -5265,6 +5267,21 @@ populate_lr_context(struct intel_context *ce,
 	return 0;
 }
 
+static int context_clear_lmem(struct drm_i915_gem_object *ctx_obj)
+{
+	void *vaddr;
+
+	vaddr = i915_gem_object_pin_map(ctx_obj, I915_MAP_WC);
+	if (IS_ERR(vaddr))
+		return PTR_ERR(vaddr);
+
+	memset64(vaddr, 0, ctx_obj->base.size / sizeof(u64));
+
+	i915_gem_object_unpin_map(ctx_obj);
+
+	return 0;
+}
+
 static int __execlists_context_alloc(struct intel_context *ce,
 				     struct intel_engine_cs *engine)
 {
@@ -5285,10 +5302,22 @@ static int __execlists_context_alloc(struct intel_context *ce,
 		context_size += PAGE_SIZE;
 	}
 
-	ctx_obj = i915_gem_object_create_shmem(engine->i915, context_size);
+	if (HAS_LMEM(engine->i915)) {
+		ctx_obj = i915_gem_object_create_lmem(engine->i915,
+						      context_size,
+						      I915_BO_ALLOC_CONTIGUOUS);
+	} else {
+		ctx_obj = i915_gem_object_create_shmem(engine->i915, context_size);
+	}
 	if (IS_ERR(ctx_obj))
 		return PTR_ERR(ctx_obj);
 
+	if (HAS_LMEM(engine->i915)) {
+		ret = context_clear_lmem(ctx_obj);
+		if (ret)
+			goto error_deref_obj;
+	}
+
 	vma = i915_vma_instance(ctx_obj, &engine->gt->ggtt->vm, NULL);
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
-- 
2.26.2