[igt-dev] [PATCH i-g-t v4 1/5] lib/xe: add visible vram helpers

[Matthew Auld]

Add helpers for object creation and querying the cpu_visible related
bits. Keep it backwards compat to ensure IGT can be merged in any order.
At some later point we can remove the compat layer.

v2: Make it backwards compat with older kernels
v3 (José): Add TODO for removing backwards compat layer

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
Cc: José Roberto de Souza <jose.souza at intel.com>
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
---
 lib/xe/xe_query.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++-
 lib/xe/xe_query.h |  6 +++
 2 files changed, 103 insertions(+), 1 deletion(-)

diff --git a/lib/xe/xe_query.c b/lib/xe/xe_query.c
index f535ad853..8963c7b06 100644
--- a/lib/xe/xe_query.c
+++ b/lib/xe/xe_query.c
@@ -140,6 +140,17 @@ static uint64_t gt_vram_size(const struct drm_xe_query_mem_usage *mem_usage,
 	return 0;
 }
 
+static uint64_t gt_visible_vram_size(const struct drm_xe_query_mem_usage *mem_usage,
+				     const struct drm_xe_query_gts *gts, int gt)
+{
+	int region_idx = ffs(native_region_for_gt(gts, gt)) - 1;
+
+	if (XE_IS_CLASS_VRAM(&mem_usage->regions[region_idx]))
+		return mem_usage->regions[region_idx].cpu_visible_size;
+
+	return 0;
+}
+
 static bool __mem_has_vram(struct drm_xe_query_mem_usage *mem_usage)
 {
 	for (int i = 0; i < mem_usage->num_regions; i++)
@@ -246,9 +257,14 @@ struct xe_device *xe_device_get(int fd)
 	xe_dev->hw_engines = xe_query_engines_new(fd, &xe_dev->number_hw_engines);
 	xe_dev->mem_usage = xe_query_mem_usage_new(fd);
 	xe_dev->vram_size = calloc(xe_dev->number_gt, sizeof(*xe_dev->vram_size));
-	for (int gt = 0; gt < xe_dev->number_gt; gt++)
+	xe_dev->visible_vram_size = calloc(xe_dev->number_gt, sizeof(*xe_dev->visible_vram_size));
+	for (int gt = 0; gt < xe_dev->number_gt; gt++) {
 		xe_dev->vram_size[gt] = gt_vram_size(xe_dev->mem_usage,
 						     xe_dev->gts, gt);
+		xe_dev->visible_vram_size[gt] =
+			gt_visible_vram_size(xe_dev->mem_usage,
+					     xe_dev->gts, gt);
+	}
 	xe_dev->default_alignment = __mem_default_alignment(xe_dev->mem_usage);
 	xe_dev->has_vram = __mem_has_vram(xe_dev->mem_usage);
 
@@ -383,6 +399,37 @@ uint64_t vram_memory(int fd, int gt)
 	return xe_has_vram(fd) ? native_region_for_gt(xe_dev->gts, gt) : 0;
 }
 
+static uint64_t __xe_visible_vram_size(int fd, int gt)
+{
+	struct xe_device *xe_dev;
+
+	xe_dev = find_in_cache(fd);
+	igt_assert(xe_dev);
+
+	return xe_dev->visible_vram_size[gt];
+}
+
+/**
+ * visible_vram_memory:
+ * @fd: xe device fd
+ * @gt: gt id
+ *
+ * Returns vram memory bitmask for xe device @fd and @gt id, with
+ * XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM also set, to ensure that CPU access is
+ * possible.
+ */
+uint64_t visible_vram_memory(int fd, int gt)
+{
+	/*
+	 * TODO: Keep it backwards compat for now. Fixup once the kernel side
+	 * has landed.
+	 */
+	if (__xe_visible_vram_size(fd, gt))
+		return vram_memory(fd, gt) | XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM;
+	else
+		return vram_memory(fd, gt); /* older kernel */
+}
+
 /**
  * vram_if_possible:
  * @fd: xe device fd
@@ -396,6 +443,32 @@ uint64_t vram_if_possible(int fd, int gt)
 	return vram_memory(fd, gt) ?: system_memory(fd);
 }
 
+/**
+ * visible_vram_if_possible:
+ * @fd: xe device fd
+ * @gt: gt id
+ *
+ * Returns vram memory bitmask for xe device @fd and @gt id or system memory if
+ * there's no vram memory available for @gt. Also attaches the
+ * XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM to ensure that CPU access is possible
+ * when using vram.
+ */
+uint64_t visible_vram_if_possible(int fd, int gt)
+{
+	uint64_t regions = all_memory_regions(fd);
+	uint64_t system_memory = regions & 0x1;
+	uint64_t vram = regions & (0x2 << gt);
+
+	/*
+	 * TODO: Keep it backwards compat for now. Fixup once the kernel side
+	 * has landed.
+	 */
+	if (__xe_visible_vram_size(fd, gt))
+		return vram ? vram | XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM : system_memory;
+	else
+		return vram ? vram : system_memory; /* older kernel */
+}
+
 /**
  * xe_hw_engines:
  * @fd: xe device fd
@@ -536,6 +609,28 @@ uint64_t xe_vram_size(int fd, int gt)
 	return xe_dev->vram_size[gt];
 }
 
+/**
+ * xe_visible_vram_size:
+ * @fd: xe device fd
+ * @gt: gt
+ *
+ * Returns size of visible vram of xe device @fd.
+ */
+uint64_t xe_visible_vram_size(int fd, int gt)
+{
+	uint64_t visible_size;
+
+	/*
+	 * TODO: Keep it backwards compat for now. Fixup once the kernel side
+	 * has landed.
+	 */
+	visible_size = __xe_visible_vram_size(fd, gt);
+	if (!visible_size) /* older kernel */
+		visible_size = xe_vram_size(fd, gt);
+
+	return visible_size;
+}
+
 /**
  * xe_get_default_alignment:
  * @fd: xe device fd
@@ -552,6 +647,7 @@ xe_dev_FN(xe_get_default_alignment, default_alignment, uint32_t);
  */
 xe_dev_FN(xe_va_bits, va_bits, uint32_t);
 
+
 /**
  * xe_dev_id:
  * @fd: xe device fd
diff --git a/lib/xe/xe_query.h b/lib/xe/xe_query.h
index 68ca5a680..1b74c58ab 100644
--- a/lib/xe/xe_query.h
+++ b/lib/xe/xe_query.h
@@ -47,6 +47,9 @@ struct xe_device {
 	/** @vram_size: array of vram sizes for all gts */
 	uint64_t *vram_size;
 
+	/** @visible_vram_size: array of visible vram sizes for all gts */
+	uint64_t *visible_vram_size;
+
 	/** @default_alignment: safe alignment regardless region location */
 	uint32_t default_alignment;
 
@@ -80,7 +83,9 @@ unsigned int xe_number_gt(int fd);
 uint64_t all_memory_regions(int fd);
 uint64_t system_memory(int fd);
 uint64_t vram_memory(int fd, int gt);
+uint64_t visible_vram_memory(int fd, int gt);
 uint64_t vram_if_possible(int fd, int gt);
+uint64_t visible_vram_if_possible(int fd, int gt);
 struct drm_xe_engine_class_instance *xe_hw_engines(int fd);
 struct drm_xe_engine_class_instance *xe_hw_engine(int fd, int idx);
 struct drm_xe_query_mem_region *xe_mem_region(int fd, uint64_t region);
@@ -91,6 +96,7 @@ struct drm_xe_query_config *xe_config(int fd);
 unsigned int xe_number_hw_engines(int fd);
 bool xe_has_vram(int fd);
 uint64_t xe_vram_size(int fd, int gt);
+uint64_t xe_visible_vram_size(int fd, int gt);
 uint32_t xe_get_default_alignment(int fd);
 uint32_t xe_va_bits(int fd);
 uint16_t xe_dev_id(int fd);
-- 
2.41.0