On Thu, 12 Aug 2021, Ayaz A Siddiqui <ayaz.siddiqui@xxxxxxxxx> wrote:
> From: Srinivasan Shanmugam <srinivasan.s@xxxxxxxxx>
>
> 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 <srinivasan.s@xxxxxxxxx>
> Signed-off-by: Ayaz A Siddiqui <ayaz.siddiqui@xxxxxxxxx>
> Cc: Chris Wilson <chris.p.wilson@xxxxxxxxx>
> Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
> ---
> 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;
Please do not roll your own list implementations. Use list.h.
BR,
Jani.
> +};
> +
> /* 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)
--
Jani Nikula, Intel Open Source Graphics Center
