drm/i915: avoid concurrent writes to aux_inv

GPU hangs have been observed when multiple engines write to the
same aux_inv register at the same time. To avoid this each engine
should only invalidate its own auxiliary table. The function
gen12_emit_flush_xcs() currently invalidate the auxiliary table for
all engines because the rq->engine is not necessarily the engine
eventually carrying out the request, and potentially the engine
could even be a virtual one (with engine->instance being -1).
With the MMIO remap feature, we can actually set bit 17 of MI_LRI
instruction and let the hardware to figure out the local aux_inv
register at runtime to avoid invalidating auxiliary table for all
engines.

Bspec: 45728

v2: Invalidate AUX table for indirect context as well.

Cc: Stuart Summers <stuart.summers@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Chris Wilson <chris.p.wilson@intel.com>
Signed-off-by: Fei Yang <fei.yang@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220328171650.1900674-1-fei.yang@intel.com

diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
index 3614888..047b5a7 100644 (file)
--- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
@@ -6,7 +6,6 @@
 #include "gen8_engine_cs.h"
 #include "i915_drv.h"
 #include "intel_gpu_commands.h"
-#include "intel_gt_regs.h"
 #include "intel_lrc.h"
 #include "intel_ring.h"
 
@@ -165,33 +164,9 @@ static u32 preparser_disable(bool state)
        return MI_ARB_CHECK | 1 << 8 | state;
 }
 
-static i915_reg_t aux_inv_reg(const struct intel_engine_cs *engine)
+u32 *gen12_emit_aux_table_inv(u32 *cs, const i915_reg_t inv_reg)
 {
-       static const i915_reg_t vd[] = {
-               GEN12_VD0_AUX_NV,
-               GEN12_VD1_AUX_NV,
-               GEN12_VD2_AUX_NV,
-               GEN12_VD3_AUX_NV,
-       };
-
-       static const i915_reg_t ve[] = {
-               GEN12_VE0_AUX_NV,
-               GEN12_VE1_AUX_NV,
-       };
-
-       if (engine->class == VIDEO_DECODE_CLASS)
-               return vd[engine->instance];
-
-       if (engine->class == VIDEO_ENHANCEMENT_CLASS)
-               return ve[engine->instance];
-
-       GEM_BUG_ON("unknown aux_inv reg\n");
-       return INVALID_MMIO_REG;
-}
-
-static u32 *gen12_emit_aux_table_inv(const i915_reg_t inv_reg, u32 *cs)
-{
-       *cs++ = MI_LOAD_REGISTER_IMM(1);
+       *cs++ = MI_LOAD_REGISTER_IMM(1) | MI_LRI_MMIO_REMAP_EN;
        *cs++ = i915_mmio_reg_offset(inv_reg);
        *cs++ = AUX_INV;
        *cs++ = MI_NOOP;
@@ -274,7 +249,7 @@ int gen12_emit_flush_rcs(struct i915_request *rq, u32 mode)
 
                if (!HAS_FLAT_CCS(rq->engine->i915)) {
                        /* hsdes: 1809175790 */
-                       cs = gen12_emit_aux_table_inv(GEN12_GFX_CCS_AUX_NV, cs);
+                       cs = gen12_emit_aux_table_inv(cs, GEN12_GFX_CCS_AUX_NV);
                }
 
                *cs++ = preparser_disable(false);
@@ -293,10 +268,12 @@ int gen12_emit_flush_xcs(struct i915_request *rq, u32 mode)
        if (mode & EMIT_INVALIDATE) {
                cmd += 2;
 
-               if (!HAS_FLAT_CCS(rq->engine->i915)) {
+               if (!HAS_FLAT_CCS(rq->engine->i915) &&
+                   (rq->engine->class == VIDEO_DECODE_CLASS ||
+                    rq->engine->class == VIDEO_ENHANCEMENT_CLASS)) {
                        aux_inv = rq->engine->mask & ~BIT(BCS0);
                        if (aux_inv)
-                               cmd += 2 * hweight32(aux_inv) + 2;
+                               cmd += 4;
                }
        }
 
@@ -329,15 +306,10 @@ int gen12_emit_flush_xcs(struct i915_request *rq, u32 mode)
        *cs++ = 0; /* value */
 
        if (aux_inv) { /* hsdes: 1809175790 */
-               struct intel_engine_cs *engine;
-               unsigned int tmp;
-
-               *cs++ = MI_LOAD_REGISTER_IMM(hweight32(aux_inv));
-               for_each_engine_masked(engine, rq->engine->gt, aux_inv, tmp) {
-                       *cs++ = i915_mmio_reg_offset(aux_inv_reg(engine));
-                       *cs++ = AUX_INV;
-               }
-               *cs++ = MI_NOOP;
+               if (rq->engine->class == VIDEO_DECODE_CLASS)
+                       cs = gen12_emit_aux_table_inv(cs, GEN12_VD0_AUX_NV);
+               else
+                       cs = gen12_emit_aux_table_inv(cs, GEN12_VE0_AUX_NV);
        }
 
        if (mode & EMIT_INVALIDATE)

diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.h b/drivers/gpu/drm/i915/gt/gen8_engine_cs.h
index cc6e21d..107ab42 100644 (file)
--- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.h
+++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.h
@@ -10,7 +10,7 @@
 #include <linux/types.h>
 
 #include "i915_gem.h" /* GEM_BUG_ON */
-
+#include "intel_gt_regs.h"
 #include "intel_gpu_commands.h"
 
 struct i915_request;
@@ -38,6 +38,8 @@ u32 *gen8_emit_fini_breadcrumb_rcs(struct i915_request *rq, u32 *cs);
 u32 *gen11_emit_fini_breadcrumb_rcs(struct i915_request *rq, u32 *cs);
 u32 *gen12_emit_fini_breadcrumb_rcs(struct i915_request *rq, u32 *cs);
 
+u32 *gen12_emit_aux_table_inv(u32 *cs, const i915_reg_t inv_reg);
+
 static inline u32 *
 __gen8_emit_pipe_control(u32 *batch, u32 flags0, u32 flags1, u32 offset)
 {

diff --git a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
index d112ffd..4243be0 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
+++ b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
@@ -144,6 +144,7 @@
 #define MI_LOAD_REGISTER_IMM(x)        MI_INSTR(0x22, 2*(x)-1)
 /* Gen11+. addr = base + (ctx_restore ? offset & GENMASK(12,2) : offset) */
 #define   MI_LRI_LRM_CS_MMIO           REG_BIT(19)
+#define   MI_LRI_MMIO_REMAP_EN         REG_BIT(17)
 #define   MI_LRI_FORCE_POSTED          (1<<12)
 #define MI_LOAD_REGISTER_IMM_MAX_REGS (126)
 #define MI_STORE_REGISTER_MEM        MI_INSTR(0x24, 1)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 07bef71..dffef6a 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1208,6 +1208,10 @@ gen12_emit_indirect_ctx_rcs(const struct intel_context *ce, u32 *cs)
            IS_DG2_G11(ce->engine->i915))
                cs = gen8_emit_pipe_control(cs, PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE, 0);
 
+       /* hsdes: 1809175790 */
+       if (!HAS_FLAT_CCS(ce->engine->i915))
+               cs = gen12_emit_aux_table_inv(cs, GEN12_GFX_CCS_AUX_NV);
+
        return cs;
 }
 
@@ -1225,6 +1229,14 @@ gen12_emit_indirect_ctx_xcs(const struct intel_context *ce, u32 *cs)
                                                    PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE,
                                                    0);
 
+       /* hsdes: 1809175790 */
+       if (!HAS_FLAT_CCS(ce->engine->i915)) {
+               if (ce->engine->class == VIDEO_DECODE_CLASS)
+                       cs = gen12_emit_aux_table_inv(cs, GEN12_VD0_AUX_NV);
+               else if (ce->engine->class == VIDEO_ENHANCEMENT_CLASS)
+                       cs = gen12_emit_aux_table_inv(cs, GEN12_VE0_AUX_NV);
+       }
+
        return cs;
 }