On Fri, 23 Sep 2022 13:11:43 -0700, Umesh Nerlige Ramappa wrote:
>
Hi Umesh,
> Some SKUs of same gen12 platform may have different oactxctrl
> offsets. For gen12, determine oactxctrl offsets at runtime.
So seems we are writing code to extract static information for products
just because it is not documented?
>
> v2: (Lionel)
> - Move MI definitions to intel_gpu_commands.h
> - Ensure __find_reg_in_lri does read past context image size
>
> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/intel_gpu_commands.h | 4 +
> drivers/gpu/drm/i915/i915_perf.c | 146 +++++++++++++++----
> drivers/gpu/drm/i915/i915_perf_oa_regs.h | 2 +-
> 3 files changed, 121 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> index d4e9702d3c8e..f50ea92910d9 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gpu_commands.h
> @@ -187,6 +187,10 @@
> #define MI_BATCH_RESOURCE_STREAMER REG_BIT(10)
> #define MI_BATCH_PREDICATE REG_BIT(15) /* HSW+ on RCS only*/
>
> +#define MI_OPCODE(x) (((x) >> 23) & 0x3f)
> +#define IS_MI_LRI_CMD(x) (MI_OPCODE(x) == MI_OPCODE(MI_INSTR(0x22, 0)))
> +#define MI_LRI_LEN(x) (((x) & 0xff) + 1)
> +
> /*
> * 3D instructions used by the kernel
> */
> diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
> index cd57b5836386..fb705f24705b 100644
> --- a/drivers/gpu/drm/i915/i915_perf.c
> +++ b/drivers/gpu/drm/i915/i915_perf.c
> @@ -1358,6 +1358,64 @@ static int gen12_get_render_context_id(struct i915_perf_stream *stream)
> return 0;
> }
>
> +#define __valid_oactxctrl_offset(x) ((x) && (x) != U32_MAX)
> +static bool __find_reg_in_lri(u32 *state, u32 reg, u32 *offset, u32 end)
> +{
> + u32 idx = *offset;
> + u32 len = min(MI_LRI_LEN(state[idx]) + idx, end);
The code below works only if MI_LRI_LEN() is an even number (because of
'idx += 2', which I think should always be the case but not sure if we it
makes sense to add an assert etc.
> +
> + idx++;
> + for (; idx < len; idx += 2)
> + if (state[idx] == reg)
> + break;
> +
> + *offset = idx;
> + return state[idx] == reg;
I think this can be a bug if 'idx > len' but 'state[idx] == reg'. So we
need to do something like:
static bool __find_reg_in_lri(u32 *state, u32 reg, u32 *offset, u32 end)
{
u32 idx = *offset;
u32 len = min(MI_LRI_LEN(state[idx]) + idx, end);
bool found = false;
idx++;
for (; idx < len; idx += 2)
if (state[idx] == reg)
found = true;
*offset = idx;
return found;
> +}
> +
> +static u32 __context_image_offset(struct intel_context *ce, u32 reg)
> +{
> + u32 offset, len = (ce->engine->context_size - PAGE_SIZE) / 4;
> + u32 *state = ce->lrc_reg_state;
> +
> + for (offset = 0; offset < len; ) {
> + if (IS_MI_LRI_CMD(state[offset])) {
> + if (__find_reg_in_lri(state, reg, &offset, len))
> + break;
> + } else {
> + offset++;
> + }
> + }
> +
> + return offset < len ? offset : U32_MAX;
> +}
> +
> +static int __set_oa_ctx_ctrl_offset(struct intel_context *ce)
I have seen people complain about unnecessary double underscores in front
of function names ;-)
> +{
> + i915_reg_t reg = GEN12_OACTXCONTROL(ce->engine->mmio_base);
> + struct i915_perf *perf = &ce->engine->i915->perf;
> + u32 saved_offset = perf->ctx_oactxctrl_offset;
> + u32 offset;
> +
> + /* Do this only once. Failure is stored as offset of U32_MAX */
> + if (saved_offset)
> + return 0;
But if saved_offset is U32_MAX we should be returning -ENODEV?
> +
> + offset = __context_image_offset(ce, i915_mmio_reg_offset(reg));
> + perf->ctx_oactxctrl_offset = offset;
> +
> + drm_dbg(&ce->engine->i915->drm,
> + "%s oa ctx control at 0x%08x dword offset\n",
> + ce->engine->name, offset);
> +
> + return __valid_oactxctrl_offset(offset) ? 0 : -ENODEV;
> +}
> +
> +static bool engine_supports_mi_query(struct intel_engine_cs *engine)
> +{
> + return engine->class == RENDER_CLASS;
> +}
> +
> /**
> * oa_get_render_ctx_id - determine and hold ctx hw id
> * @stream: An i915-perf stream opened for OA metrics
> @@ -1377,6 +1435,17 @@ static int oa_get_render_ctx_id(struct i915_perf_stream *stream)
> if (IS_ERR(ce))
> return PTR_ERR(ce);
>
> + if (engine_supports_mi_query(stream->engine)) {
> + ret = __set_oa_ctx_ctrl_offset(ce);
> + if (ret && !(stream->sample_flags & SAMPLE_OA_REPORT)) {
This is not a problem in SAMPLE_OA_REPORT case?
> + intel_context_unpin(ce);
> + drm_err(&stream->perf->i915->drm,
> + "Enabling perf query failed for %s\n",
> + stream->engine->name);
> + return ret;
> + }
> + }
> +
> switch (GRAPHICS_VER(ce->engine->i915)) {
> case 7: {
> /*
> @@ -2408,10 +2477,11 @@ static int gen12_configure_oar_context(struct i915_perf_stream *stream,
> int err;
> struct intel_context *ce = stream->pinned_ctx;
> u32 format = stream->oa_buffer.format;
> + u32 offset = stream->perf->ctx_oactxctrl_offset;
> struct flex regs_context[] = {
> {
> GEN8_OACTXCONTROL,
> - stream->perf->ctx_oactxctrl_offset + 1,
> + offset + 1,
> active ? GEN8_OA_COUNTER_RESUME : 0,
> },
> };
> @@ -2436,15 +2506,18 @@ static int gen12_configure_oar_context(struct i915_perf_stream *stream,
> },
> };
>
> - /* Modify the context image of pinned context with regs_context*/
> - err = intel_context_lock_pinned(ce);
> - if (err)
> - return err;
> + /* Modify the context image of pinned context with regs_context */
> + if (__valid_oactxctrl_offset(offset)) {
This check is not needed, if we didn't have valid a offset we should return
error from oa_get_render_ctx_id.
> + err = intel_context_lock_pinned(ce);
> + if (err)
> + return err;
>
> - err = gen8_modify_context(ce, regs_context, ARRAY_SIZE(regs_context));
> - intel_context_unlock_pinned(ce);
> - if (err)
> - return err;
> + err = gen8_modify_context(ce, regs_context,
> + ARRAY_SIZE(regs_context));
> + intel_context_unlock_pinned(ce);
> + if (err)
> + return err;
> + }
>
> /* Apply regs_lri using LRI with pinned context */
> return gen8_modify_self(ce, regs_lri, ARRAY_SIZE(regs_lri), active);
> @@ -2566,6 +2639,7 @@ lrc_configure_all_contexts(struct i915_perf_stream *stream,
> const struct i915_oa_config *oa_config,
> struct i915_active *active)
> {
> + u32 ctx_oactxctrl = stream->perf->ctx_oactxctrl_offset;
> /* The MMIO offsets for Flex EU registers aren't contiguous */
> const u32 ctx_flexeu0 = stream->perf->ctx_flexeu0_offset;
> #define ctx_flexeuN(N) (ctx_flexeu0 + 2 * (N) + 1)
> @@ -2576,7 +2650,7 @@ lrc_configure_all_contexts(struct i915_perf_stream *stream,
> },
> {
> GEN8_OACTXCONTROL,
> - stream->perf->ctx_oactxctrl_offset + 1,
> + ctx_oactxctrl + 1,
> },
> { EU_PERF_CNTL0, ctx_flexeuN(0) },
> { EU_PERF_CNTL1, ctx_flexeuN(1) },
> @@ -4545,6 +4619,37 @@ static void oa_init_supported_formats(struct i915_perf *perf)
> }
> }
>
> +static void i915_perf_init_info(struct drm_i915_private *i915)
> +{
> + struct i915_perf *perf = &i915->perf;
> +
> + switch (GRAPHICS_VER(i915)) {
> + case 8:
> + perf->ctx_oactxctrl_offset = 0x120;
> + perf->ctx_flexeu0_offset = 0x2ce;
> + perf->gen8_valid_ctx_bit = BIT(25);
> + break;
> + case 9:
> + perf->ctx_oactxctrl_offset = 0x128;
> + perf->ctx_flexeu0_offset = 0x3de;
> + perf->gen8_valid_ctx_bit = BIT(16);
> + break;
> + case 11:
> + perf->ctx_oactxctrl_offset = 0x124;
> + perf->ctx_flexeu0_offset = 0x78e;
> + perf->gen8_valid_ctx_bit = BIT(16);
> + break;
> + case 12:
> + /*
> + * Calculate offset at runtime in oa_pin_context for gen12 and
> + * cache the value in perf->ctx_oactxctrl_offset.
> + */
What about ctx_flexeu0_offset and gen8_valid_ctx_bit for Gen12+?
Thanks.
--
Ashutosh
