From: Tejas Upadhyay <tejas.upadhyay@intel.com>
Date: Thu, 5 Mar 2026 12:19:05 +0000 (+0530)
Subject: drm/xe/pat: define coh_mode 2way
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=411389d29eab5325e2b250b1cd2ddb567abb7bbb;p=thirdparty%2Fkernel%2Flinux.git

drm/xe/pat: define coh_mode 2way

Defining 2way (two-way coherency) is critical for
Xe3p_LPG (Nova Lake P) platforms to support L2 flush
optimization safely.

This mode allows the driver to skip certain manual cache
flushes (L2 flush optimization) without risking memory
corruption because the hardware ensures the most recent
data is visible to both entities.

Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patch.msgid.link/20260305121902.1892593-8-tejas.upadhyay@intel.com
Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
---

diff --git a/drivers/gpu/drm/xe/xe_pat.c b/drivers/gpu/drm/xe/xe_pat.c
index 34c9031e1e74b..356f53bdb83c4 100644
--- a/drivers/gpu/drm/xe/xe_pat.c
+++ b/drivers/gpu/drm/xe/xe_pat.c
@@ -92,7 +92,7 @@ struct xe_pat_ops {
 };
 
 static const struct xe_pat_table_entry xelp_pat_table[] = {
-	[0] = { XELP_PAT_WB, XE_COH_AT_LEAST_1WAY },
+	[0] = { XELP_PAT_WB, XE_COH_1WAY },
 	[1] = { XELP_PAT_WC, XE_COH_NONE },
 	[2] = { XELP_PAT_WT, XE_COH_NONE },
 	[3] = { XELP_PAT_UC, XE_COH_NONE },
@@ -102,19 +102,19 @@ static const struct xe_pat_table_entry xehpc_pat_table[] = {
 	[0] = { XELP_PAT_UC, XE_COH_NONE },
 	[1] = { XELP_PAT_WC, XE_COH_NONE },
 	[2] = { XELP_PAT_WT, XE_COH_NONE },
-	[3] = { XELP_PAT_WB, XE_COH_AT_LEAST_1WAY },
+	[3] = { XELP_PAT_WB, XE_COH_1WAY },
 	[4] = { XEHPC_PAT_CLOS(1) | XELP_PAT_WT, XE_COH_NONE },
-	[5] = { XEHPC_PAT_CLOS(1) | XELP_PAT_WB, XE_COH_AT_LEAST_1WAY },
+	[5] = { XEHPC_PAT_CLOS(1) | XELP_PAT_WB, XE_COH_1WAY },
 	[6] = { XEHPC_PAT_CLOS(2) | XELP_PAT_WT, XE_COH_NONE },
-	[7] = { XEHPC_PAT_CLOS(2) | XELP_PAT_WB, XE_COH_AT_LEAST_1WAY },
+	[7] = { XEHPC_PAT_CLOS(2) | XELP_PAT_WB, XE_COH_1WAY },
 };
 
 static const struct xe_pat_table_entry xelpg_pat_table[] = {
 	[0] = { XELPG_PAT_0_WB, XE_COH_NONE },
 	[1] = { XELPG_PAT_1_WT, XE_COH_NONE },
 	[2] = { XELPG_PAT_3_UC, XE_COH_NONE },
-	[3] = { XELPG_PAT_0_WB | XELPG_2_COH_1W, XE_COH_AT_LEAST_1WAY },
-	[4] = { XELPG_PAT_0_WB | XELPG_3_COH_2W, XE_COH_AT_LEAST_1WAY },
+	[3] = { XELPG_PAT_0_WB | XELPG_2_COH_1W, XE_COH_1WAY },
+	[4] = { XELPG_PAT_0_WB | XELPG_3_COH_2W, XE_COH_2WAY },
 };
 
 /*
@@ -147,7 +147,7 @@ static const struct xe_pat_table_entry xelpg_pat_table[] = {
 			REG_FIELD_PREP(XE2_L3_POLICY, l3_policy) | \
 			REG_FIELD_PREP(XE2_L4_POLICY, l4_policy) | \
 			REG_FIELD_PREP(XE2_COH_MODE, __coh_mode), \
-		.coh_mode = __coh_mode ? XE_COH_AT_LEAST_1WAY : XE_COH_NONE, \
+		.coh_mode = __coh_mode ? __coh_mode : XE_COH_NONE, \
 		.valid = 1 \
 	}
 
diff --git a/drivers/gpu/drm/xe/xe_pat.h b/drivers/gpu/drm/xe/xe_pat.h
index c7e2a53d8cee9..a1e287c08f570 100644
--- a/drivers/gpu/drm/xe/xe_pat.h
+++ b/drivers/gpu/drm/xe/xe_pat.h
@@ -28,8 +28,9 @@ struct xe_pat_table_entry {
 	/**
 	 * @coh_mode: The GPU coherency mode that @value maps to.
 	 */
-#define XE_COH_NONE          1
-#define XE_COH_AT_LEAST_1WAY 2
+#define XE_COH_NONE		1
+#define XE_COH_1WAY		2
+#define XE_COH_2WAY		3
 	u16 coh_mode;
 
 	/**
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 5572e12c2a7eb..c0d8f5db019d0 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -3465,7 +3465,7 @@ static int vm_bind_ioctl_check_args(struct xe_device *xe, struct xe_vm *vm,
 			goto free_bind_ops;
 		}
 
-		if (XE_WARN_ON(coh_mode > XE_COH_AT_LEAST_1WAY)) {
+		if (XE_WARN_ON(coh_mode > XE_COH_2WAY)) {
 			err = -EINVAL;
 			goto free_bind_ops;
 		}
diff --git a/drivers/gpu/drm/xe/xe_vm_madvise.c b/drivers/gpu/drm/xe/xe_vm_madvise.c
index 869db304d96de..431be53be56ff 100644
--- a/drivers/gpu/drm/xe/xe_vm_madvise.c
+++ b/drivers/gpu/drm/xe/xe_vm_madvise.c
@@ -309,7 +309,7 @@ static bool madvise_args_are_sane(struct xe_device *xe, const struct drm_xe_madv
 		if (XE_IOCTL_DBG(xe, !coh_mode))
 			return false;
 
-		if (XE_WARN_ON(coh_mode > XE_COH_AT_LEAST_1WAY))
+		if (XE_WARN_ON(coh_mode > XE_COH_2WAY))
 			return false;
 
 		if (XE_IOCTL_DBG(xe, args->pat_index.pad))