[Intel-gfx] [PATCH 28/39] drm/i915/tgl: add GEN12_MAX_CONTEXT_HW_ID

[Lucas De Marchi]

From: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>

Like Gen11, Gen12 has 11 available bits for the ctx id field. However,
the last value (0x7FF) is reserved to indicate "invalid context", so
we need to reduce the maximum number of contexts by 1 compared to Gen11.

Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 4 +++-
 drivers/gpu/drm/i915/i915_drv.h             | 2 ++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index a6b0cb714292..c44b346633ad 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -173,7 +173,9 @@ static inline int new_hw_id(struct drm_i915_private *i915, gfp_t gfp)
 
 	lockdep_assert_held(&i915->contexts.mutex);
 
-	if (INTEL_GEN(i915) >= 11)
+	if (INTEL_GEN(i915) >= 12)
+		max = GEN12_MAX_CONTEXT_HW_ID;
+	else if (INTEL_GEN(i915) >= 11)
 		max = GEN11_MAX_CONTEXT_HW_ID;
 	else if (USES_GUC_SUBMISSION(i915))
 		/*
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 8d57e9680c99..49c8b49d0e1e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1604,6 +1604,8 @@ struct drm_i915_private {
 #define MAX_CONTEXT_HW_ID (1<<21) /* exclusive */
 #define MAX_GUC_CONTEXT_HW_ID (1 << 20) /* exclusive */
 #define GEN11_MAX_CONTEXT_HW_ID (1<<11) /* exclusive */
+/* in Gen12 ID 0x7FF is reserved to indicate "invalid context" */
+#define GEN12_MAX_CONTEXT_HW_ID	(GEN11_MAX_CONTEXT_HW_ID - 1)
 		struct list_head hw_id_list;
 	} contexts;
 
-- 
2.21.0