drm/i915/gvt: add interface to check if context is inhibit

No functional change, just for easy to use.

v4:
- refine comment (Kevin)

Signed-off-by: Weinan Li <weinan.z.li@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

2 files changed, 16 insertions, 10 deletions

diff --git a/drivers/gpu/drm/i915/gvt/mmio_context.c b/drivers/gpu/drm/i915/gvt/mmio_context.c
index ca4ba56fd60c..1bc1b28eb9e1 100644
--- a/drivers/gpu/drm/i915/gvt/mmio_context.c
+++ b/drivers/gpu/drm/i915/gvt/mmio_context.c
@@ -295,6 +295,16 @@ static void switch_mocs(struct intel_vgpu *pre, struct intel_vgpu *next,
 
 #define CTX_CONTEXT_CONTROL_VAL 0x03
 
+bool is_inhibit_context(struct i915_gem_context *ctx, int ring_id)
+{
+        u32 *reg_state = ctx->engine[ring_id].lrc_reg_state;
+        u32 inhibit_mask =
+                _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT);
+
+        return inhibit_mask ==
+                (reg_state[CTX_CONTEXT_CONTROL_VAL] & inhibit_mask);
+}
+
 /* Switch ring mmio values (context). */
 static void switch_mmio(struct intel_vgpu *pre,
                         struct intel_vgpu *next,
@@ -302,9 +312,6 @@ static void switch_mmio(struct intel_vgpu *pre,
 {
         struct drm_i915_private *dev_priv;
         struct intel_vgpu_submission *s;
-        u32 *reg_state, ctx_ctrl;
-        u32 inhibit_mask =
-                _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT);
         struct engine_mmio *mmio;
         u32 old_v, new_v;
 
@@ -329,16 +336,13 @@ static void switch_mmio(struct intel_vgpu *pre,
                 // restore
                 if (next) {
                         s = &next->submission;
-                        reg_state =
-                                s->shadow_ctx->engine[ring_id].lrc_reg_state;
-                        ctx_ctrl = reg_state[CTX_CONTEXT_CONTROL_VAL];
                         /*
-                         * if it is an inhibit context, load in_context mmio
-                         * into HW by mmio write. If it is not, skip this mmio
-                         * write.
+                         * No need to restore the mmio which is in context state
+                         * image if it's not inhibit context, it will restore
+                         * itself.
                          */
                         if (mmio->in_context &&
-                            (ctx_ctrl & inhibit_mask) != inhibit_mask)
+                            !is_inhibit_context(s->shadow_ctx, ring_id))
                                 continue;
 
                         if (mmio->mask)
diff --git a/drivers/gpu/drm/i915/gvt/mmio_context.h b/drivers/gpu/drm/i915/gvt/mmio_context.h
index ca2c6a745673..4df87c7314c9 100644
--- a/drivers/gpu/drm/i915/gvt/mmio_context.h
+++ b/drivers/gpu/drm/i915/gvt/mmio_context.h
@@ -49,4 +49,6 @@ void intel_gvt_switch_mmio(struct intel_vgpu *pre,
 
 void intel_gvt_init_engine_mmio_context(struct intel_gvt *gvt);
 
+bool is_inhibit_context(struct i915_gem_context *ctx, int ring_id);
+
 #endif