[PATCH 1/3] drm/xe: Introduced needs_scratch bit in device descriptor

[Oak Zeng]

On some platform, scratch page is needed for out of bound prefetch
to work. Introduce a bit in device descriptor to specify whether
this device needs scratch page to work.

v2: introduce a needs_scratch bit in device info (Thomas, Jonathan)

Signed-off-by: Oak Zeng <oak.zeng at intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
 drivers/gpu/drm/xe/xe_device_types.h | 3 +++
 drivers/gpu/drm/xe/xe_pci.c          | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index c0e886bac183..1197ab31e528 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -45,6 +45,7 @@ struct xe_pxp;
 #define GRAPHICS_VERx100(xe) ((xe)->info.graphics_verx100)
 #define MEDIA_VERx100(xe) ((xe)->info.media_verx100)
 #define IS_DGFX(xe) ((xe)->info.is_dgfx)
+#define NEEDS_SCRATCH(xe) ((xe)->info.needs_scratch)
 
 #define XE_VRAM_FLAGS_NEED64K		BIT(0)
 
@@ -318,6 +319,8 @@ struct xe_device {
 		u8 has_usm:1;
 		/** @info.is_dgfx: is discrete device */
 		u8 is_dgfx:1;
+		/** @info.needs_scratch: needs scratch page for oob prefetch to work */
+		u8 needs_scratch:1;
 		/**
 		 * @info.probe_display: Probe display hardware.  If set to
 		 * false, the driver will behave as if there is no display
diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
index e8ef7d6b4db8..09736674a77e 100644
--- a/drivers/gpu/drm/xe/xe_pci.c
+++ b/drivers/gpu/drm/xe/xe_pci.c
@@ -67,6 +67,7 @@ struct xe_device_desc {
 	u8 has_llc:1;
 	u8 has_pxp:1;
 	u8 has_sriov:1;
+	u8 needs_scratch:1;
 	u8 skip_guc_pc:1;
 	u8 skip_mtcfg:1;
 	u8 skip_pcode:1;
@@ -353,6 +354,7 @@ static const struct xe_device_desc lnl_desc = {
 	.dma_mask_size = 46,
 	.has_display = true,
 	.has_pxp = true,
+	.needs_scratch = true,
 };
 
 static const struct xe_device_desc bmg_desc = {
@@ -361,6 +363,7 @@ static const struct xe_device_desc bmg_desc = {
 	.dma_mask_size = 46,
 	.has_display = true,
 	.has_heci_cscfi = 1,
+	.needs_scratch = true,
 };
 
 static const struct xe_device_desc ptl_desc = {
@@ -368,6 +371,7 @@ static const struct xe_device_desc ptl_desc = {
 	.dma_mask_size = 46,
 	.has_display = true,
 	.require_force_probe = true,
+	.needs_scratch = true,
 };
 
 #undef PLATFORM
@@ -643,6 +647,7 @@ static int xe_info_init_early(struct xe_device *xe,
 	xe->info.skip_guc_pc = desc->skip_guc_pc;
 	xe->info.skip_mtcfg = desc->skip_mtcfg;
 	xe->info.skip_pcode = desc->skip_pcode;
+	xe->info.needs_scratch = desc->needs_scratch;
 
 	xe->info.probe_display = IS_ENABLED(CONFIG_DRM_XE_DISPLAY) &&
 				 xe_modparam.probe_display &&
-- 
2.26.3