[PATCH v2 19/22] drm/xe/xe3p_xpc: Add support for compute walker for non-MSIx

[Lucas De Marchi <lucas.demarchi@intel.com>]

Current implementation of compute walker has dependency on GPU/SW Stack
which requires SW/UMD to wait for event from KMD to indicate
PIPE_CONTROL interrupt was done. This created latency on SW stack.

This feature adds support to generate completion interrupt from GPGPU
walker which does not support MSIx and avoid software using Pipe control
drain/idle latency.

Suggested-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Signed-off-by: S A Muqthyar Ahmed <syed.abdul.muqthyar.ahmed@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
---
v2: Rebase on split mask per engine class
---
 drivers/gpu/drm/xe/regs/xe_irq_regs.h | 1 +
 drivers/gpu/drm/xe/xe_irq.c           | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/xe/regs/xe_irq_regs.h b/drivers/gpu/drm/xe/regs/xe_irq_regs.h
index 7c2a3a1401424..9c46b5fb81412 100644
--- a/drivers/gpu/drm/xe/regs/xe_irq_regs.h
+++ b/drivers/gpu/drm/xe/regs/xe_irq_regs.h
@@ -82,6 +82,7 @@
 #define   GSC_ER_COMPLETE			REG_BIT(5)
 #define   GT_RENDER_PIPECTL_NOTIFY_INTERRUPT	REG_BIT(4)
 #define   GT_CS_MASTER_ERROR_INTERRUPT		REG_BIT(3)
+#define   GT_COMPUTE_WALKER_INTERRUPT		REG_BIT(2)
 #define   GT_RENDER_USER_INTERRUPT		REG_BIT(0)
 
 /* irqs for OTHER_KCR_INSTANCE */
diff --git a/drivers/gpu/drm/xe/xe_irq.c b/drivers/gpu/drm/xe/xe_irq.c
index 103804546b280..ac5524cbe4b9a 100644
--- a/drivers/gpu/drm/xe/xe_irq.c
+++ b/drivers/gpu/drm/xe/xe_irq.c
@@ -149,6 +149,12 @@ void xe_irq_enable_hwe(struct xe_gt *gt)
 	if (xe_device_uc_enabled(xe)) {
 		common_mask = GT_RENDER_USER_INTERRUPT |
 			      GT_RENDER_PIPECTL_NOTIFY_INTERRUPT;
+
+		/* Enable Compute Walker Interrupt for non-MSIX platforms */
+		if (GRAPHICS_VERx100(xe) >= 3511 && !xe_device_has_msix(xe)) {
+			rcs_mask |= GT_COMPUTE_WALKER_INTERRUPT;
+			ccs_mask |= GT_COMPUTE_WALKER_INTERRUPT;
+		}
 	} else {
 		common_mask = GT_RENDER_USER_INTERRUPT |
 			      GT_CS_MASTER_ERROR_INTERRUPT |

-- 
2.51.0