From: Srinivasan Shanmugam <srinivasa...@intel.com>

Program CMD_CCTL to use a mocs entry for uncached access.
This controls memory accesses by CS as it reads instructions
from the ring and batch buffers.

Signed-off-by: Srinivasan Shanmugam <srinivasa...@intel.com>
Signed-off-by: Ayaz A Siddiqui <ayaz.siddi...@intel.com>
Cc: Chris Wilson <chris.p.wil...@intel.com>
Cc: Matt Roper <matthew.d.ro...@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_mocs.c    | 96 +++++++++++++++++++++++++
 drivers/gpu/drm/i915/gt/selftest_mocs.c | 49 +++++++++++++
 drivers/gpu/drm/i915/i915_reg.h         | 16 +++++
 3 files changed, 161 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_mocs.c 
b/drivers/gpu/drm/i915/gt/intel_mocs.c
index c66e226e71499..dc3357bc228e1 100644
--- a/drivers/gpu/drm/i915/gt/intel_mocs.c
+++ b/drivers/gpu/drm/i915/gt/intel_mocs.c
@@ -25,6 +25,15 @@ struct drm_i915_mocs_table {
        u8 uc_index;
 };
 
+struct drm_i915_aux_table {
+       const char *name;
+       i915_reg_t offset;
+       u32 value;
+       u32 readmask;
+       bool skip_check;
+       struct drm_i915_aux_table *next;
+};
+
 /* Defines for the tables (XXX_MOCS_0 - XXX_MOCS_63) */
 #define _LE_CACHEABILITY(value)        ((value) << 0)
 #define _LE_TGT_CACHE(value)   ((value) << 2)
@@ -336,6 +345,86 @@ static bool has_mocs(const struct drm_i915_private *i915)
        return !IS_DGFX(i915);
 }
 
+static struct drm_i915_aux_table *
+add_aux_reg(struct drm_i915_aux_table *aux,
+           const char *name,
+           i915_reg_t offset,
+           u32 value,
+           u32 read,
+           bool skip_check)
+
+{
+       struct drm_i915_aux_table *x;
+
+       x = kmalloc(sizeof(*x), GFP_ATOMIC);
+       if (!x) {
+               DRM_ERROR("Failed to allocate aux reg '%s'\n", name);
+               return aux;
+       }
+
+       x->name = name;
+       x->offset = offset;
+       x->value = value;
+       x->readmask = read;
+       x->skip_check = skip_check;
+
+       x->next = aux;
+       return x;
+}
+
+static struct drm_i915_aux_table *
+add_cmd_cctl_override(struct drm_i915_aux_table *aux, u8 idx)
+{
+       return add_aux_reg(aux,
+                          "CMD_CCTL",
+                          RING_CMD_CCTL(0),
+                          CMD_CCTL_MOCS_OVERRIDE(idx, idx),
+                          CMD_CCTL_WRITE_OVERRIDE_MASK | 
CMD_CCTL_READ_OVERRIDE_MASK,
+                          false);
+}
+
+static const struct drm_i915_aux_table *
+build_aux_regs(const struct intel_engine_cs *engine,
+              const struct drm_i915_mocs_table *mocs)
+{
+       struct drm_i915_aux_table *aux = NULL;
+
+       if (GRAPHICS_VER(engine->i915) >= 12 &&
+           !drm_WARN_ONCE(&engine->i915->drm, !mocs->uc_index,
+                          "Platform that should have UC index defined and does 
not\n")) {
+               /*
+                * Index-0 does not operate as an uncached value as believed,
+                * but causes invalid write cycles. Steer CMD_CCTL to another
+                * uncached index.
+                */
+               aux = add_cmd_cctl_override(aux, mocs->uc_index);
+       }
+
+       return aux;
+}
+
+static void
+free_aux_regs(const struct drm_i915_aux_table *aux)
+{
+       while (aux) {
+               struct drm_i915_aux_table *next = aux->next;
+
+               kfree(aux);
+               aux = next;
+       }
+}
+
+static void apply_aux_regs(struct intel_engine_cs *engine,
+                          const struct drm_i915_aux_table *aux)
+{
+       while (aux) {
+               intel_uncore_write_fw(engine->uncore,
+                                     _MMIO(engine->mmio_base + 
i915_mmio_reg_offset(aux->offset)),
+                                     aux->value);
+               aux = aux->next;
+       }
+}
+
 static unsigned int get_mocs_settings(const struct drm_i915_private *i915,
                                      struct drm_i915_mocs_table *table)
 {
@@ -347,10 +436,12 @@ static unsigned int get_mocs_settings(const struct 
drm_i915_private *i915,
                table->size = ARRAY_SIZE(dg1_mocs_table);
                table->table = dg1_mocs_table;
                table->n_entries = GEN9_NUM_MOCS_ENTRIES;
+               table->uc_index = 1;
        } else if (GRAPHICS_VER(i915) >= 12) {
                table->size  = ARRAY_SIZE(tgl_mocs_table);
                table->table = tgl_mocs_table;
                table->n_entries = GEN9_NUM_MOCS_ENTRIES;
+               table->uc_index = 3;
        } else if (GRAPHICS_VER(i915) == 11) {
                table->size  = ARRAY_SIZE(icl_mocs_table);
                table->table = icl_mocs_table;
@@ -484,6 +575,7 @@ static void init_l3cc_table(struct intel_engine_cs *engine,
 
 void intel_mocs_init_engine(struct intel_engine_cs *engine)
 {
+       const struct drm_i915_aux_table *aux;
        struct drm_i915_mocs_table table;
        unsigned int flags;
 
@@ -500,6 +592,10 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
 
        if (flags & HAS_RENDER_L3CC && engine->class == RENDER_CLASS)
                init_l3cc_table(engine, &table);
+
+       aux = build_aux_regs(engine, &table);
+       apply_aux_regs(engine, aux);
+       free_aux_regs(aux);
 }
 
 static u32 global_mocs_offset(void)
diff --git a/drivers/gpu/drm/i915/gt/selftest_mocs.c 
b/drivers/gpu/drm/i915/gt/selftest_mocs.c
index 13d25bf2a94aa..ecadc9686ac01 100644
--- a/drivers/gpu/drm/i915/gt/selftest_mocs.c
+++ b/drivers/gpu/drm/i915/gt/selftest_mocs.c
@@ -155,6 +155,47 @@ static int read_l3cc_table(struct i915_request *rq,
        return read_regs(rq, addr, (table->n_entries + 1) / 2, offset);
 }
 
+static int read_aux_regs(struct i915_request *rq,
+                        const struct drm_i915_aux_table *r,
+                        u32 *offset)
+{
+       int err;
+
+       while (r) {
+               err = read_regs(rq,
+                               rq->engine->mmio_base + 
i915_mmio_reg_offset(r->offset), 1,
+                               offset);
+               if (err)
+                       return err;
+
+               r = r->next;
+       }
+
+       return 0;
+}
+
+static int check_aux_regs(struct intel_engine_cs *engine,
+                         const struct drm_i915_aux_table *r,
+                         u32 **vaddr)
+{
+       while (r) {
+               u32 expect = r->value & r->readmask;
+               u32 masked_value = **vaddr & r->readmask;
+
+               if (!r->skip_check && (masked_value != expect)) {
+                       pr_err("%s: Invalid entry %s[%x]=0x%x, relevant bits 
were 0x%x vs expected 0x%x\n",
+                              engine->name, r->name,
+                              i915_mmio_reg_offset(r->offset), **vaddr,
+                              masked_value, expect);
+                       return -EINVAL;
+               }
+               ++*vaddr;
+               r = r->next;
+       }
+
+       return 0;
+}
+
 static int check_mocs_table(struct intel_engine_cs *engine,
                            const struct drm_i915_mocs_table *table,
                            u32 **vaddr)
@@ -216,6 +257,7 @@ static int check_mocs_engine(struct live_mocs *arg,
                             struct intel_context *ce)
 {
        struct i915_vma *vma = arg->scratch;
+       const struct drm_i915_aux_table *aux;
        struct i915_request *rq;
        u32 offset;
        u32 *vaddr;
@@ -223,6 +265,8 @@ static int check_mocs_engine(struct live_mocs *arg,
 
        memset32(arg->vaddr, STACK_MAGIC, PAGE_SIZE / sizeof(u32));
 
+       aux = build_aux_regs(ce->engine, &arg->table);
+
        rq = intel_context_create_request(ce);
        if (IS_ERR(rq))
                return PTR_ERR(rq);
@@ -239,6 +283,8 @@ static int check_mocs_engine(struct live_mocs *arg,
                err = read_mocs_table(rq, arg->mocs, &offset);
        if (!err && ce->engine->class == RENDER_CLASS)
                err = read_l3cc_table(rq, arg->l3cc, &offset);
+       if (!err)
+               err = read_aux_regs(rq, aux, &offset);
        offset -= i915_ggtt_offset(vma);
        GEM_BUG_ON(offset > PAGE_SIZE);
 
@@ -252,10 +298,13 @@ static int check_mocs_engine(struct live_mocs *arg,
                err = check_mocs_table(ce->engine, arg->mocs, &vaddr);
        if (!err && ce->engine->class == RENDER_CLASS)
                err = check_l3cc_table(ce->engine, arg->l3cc, &vaddr);
+       if (!err)
+               err = check_aux_regs(ce->engine, aux, &vaddr);
        if (err)
                return err;
 
        GEM_BUG_ON(arg->vaddr + offset != vaddr);
+       free_aux_regs(aux);
        return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 664970f2bc62a..c8e2ca1b20796 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2551,6 +2551,22 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define RING_HWS_PGA(base)     _MMIO((base) + 0x80)
 #define RING_ID(base)          _MMIO((base) + 0x8c)
 #define RING_HWS_PGA_GEN6(base)        _MMIO((base) + 0x2080)
+
+#define RING_CMD_CCTL(base)    _MMIO((base) + 0xc4)
+/*
+ * CMD_CCTL read/write fields take a MOCS value and _not_ a table index.
+ * The lsb of each can be considered a separate enabling bit for encryption.
+ * 6:0 == default MOCS value for reads  =>  6:1 == table index for reads.
+ * 13:7 == default MOCS value for writes => 13:8 == table index for writes.
+ * 15:14 == Reserved => 31:30 are set to 0.
+ */
+#define CMD_CCTL_WRITE_OVERRIDE_MASK REG_GENMASK(13, 7)
+#define CMD_CCTL_READ_OVERRIDE_MASK REG_GENMASK(6, 0)
+#define CMD_CCTL_MOCS_OVERRIDE(write, read)                                    
\
+       _MASKED_FIELD(CMD_CCTL_WRITE_OVERRIDE_MASK | 
CMD_CCTL_READ_OVERRIDE_MASK, \
+                     REG_FIELD_PREP(CMD_CCTL_WRITE_OVERRIDE_MASK, (write) << 
1) | \
+                     REG_FIELD_PREP(CMD_CCTL_READ_OVERRIDE_MASK, (read) << 1))
+
 #define RING_RESET_CTL(base)   _MMIO((base) + 0xd0)
 #define   RESET_CTL_CAT_ERROR     REG_BIT(2)
 #define   RESET_CTL_READY_TO_RESET REG_BIT(1)
-- 
2.26.2

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