[PATCH v6 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)
v3: drop NEEDS_SCRATCH macro (Matt)

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 | 2 ++
 drivers/gpu/drm/xe/xe_pci.c          | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index 833c29fed3a3..94cc93314972 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -318,6 +318,8 @@ 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 6b5fa067b39b..3e3b1cea9bce 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 = {
@@ -369,6 +372,7 @@ static const struct xe_device_desc ptl_desc = {
 	.has_display = true,
 	.has_sriov = true,
 	.require_force_probe = true,
+	.needs_scratch = true,
 };
 
 #undef PLATFORM
@@ -644,6 +648,7 @@ 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