Re: [Intel-gfx] [PATCH 06/15] drm/i915/guc/slpc: Enable SLPC and add related H2G events

Michal Wajdeczko
2021-07-27T15:12:57Z

On 26.07.2021 21:07, Vinay Belgaumkar wrote:
> Add methods for interacting with GuC for enabling SLPC. Enable
> SLPC after GuC submission has been established. GuC load will
> fail if SLPC cannot be successfully initialized. Add various
> helper methods to set/unset the parameters for SLPC. They can
> be set using H2G calls or directly setting bits in the shared
> data structure.
>
> v2: Address several review comments, add new helpers for
> decoding the SLPC min/max frequencies. Use masks instead of hardcoded
> constants. (Michal W)
>
> v3: Split global_state_to_string function, and check for positive
> non-zero return value from intel_guc_send() (Michal W)
>
> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
> Signed-off-by: Sundaresan Sujaritha <sujaritha.sundaresan@intel.com>
> ---
> drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c | 237 ++++++++++++++++++
> .../gpu/drm/i915/gt/uc/intel_guc_slpc_types.h | 2 +
> drivers/gpu/drm/i915/gt/uc/intel_uc.c | 8 +
> 3 files changed, 247 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
> index bae4e33db0f8..f5808d2acbca 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
> @@ -45,6 +45,40 @@ void intel_guc_slpc_init_early(struct intel_guc_slpc *slpc)
> guc->slpc_selected = __guc_slpc_selected(guc);
> }
>
> +static void slpc_mem_set_param(struct slpc_shared_data *data,
> + u32 id, u32 value)
> +{
> + GEM_BUG_ON(id >= SLPC_MAX_OVERRIDE_PARAMETERS);
> + /*
> + * When the flag bit is set, corresponding value will be read
> + * and applied by slpc.

s/slpc/SLPC

> + */
> + data->override_params.bits[id >> 5] |= (1 << (id % 32));
> + data->override_params.values[id] = value;
> +}
> +
> +static void slpc_mem_set_enabled(struct slpc_shared_data *data,
> + u8 enable_id, u8 disable_id)
> +{
> + /*
> + * Enabling a param involves setting the enable_id
> + * to 1 and disable_id to 0.
> + */
> + slpc_mem_set_param(data, enable_id, 1);
> + slpc_mem_set_param(data, disable_id, 0);
> +}
> +
> +static void slpc_mem_set_disabled(struct slpc_shared_data *data,
> + u8 enable_id, u8 disable_id)
> +{
> + /*
> + * Disabling a param involves setting the enable_id
> + * to 0 and disable_id to 1.
> + */
> + slpc_mem_set_param(data, disable_id, 1);
> + slpc_mem_set_param(data, enable_id, 0);
> +}
> +
> static int slpc_shared_data_init(struct intel_guc_slpc *slpc)
> {
> struct intel_guc *guc = slpc_to_guc(slpc);
> @@ -63,6 +97,129 @@ static int slpc_shared_data_init(struct intel_guc_slpc *slpc)
> return err;
> }
>
> +static u32 slpc_get_state(struct intel_guc_slpc *slpc)
> +{
> + struct slpc_shared_data *data;
> +
> + GEM_BUG_ON(!slpc->vma);
> +
> + drm_clflush_virt_range(slpc->vaddr, sizeof(u32));
> + data = slpc->vaddr;
> +
> + return data->header.global_state;
> +}
> +
> +static bool slpc_is_running(struct intel_guc_slpc *slpc)
> +{
> + return (slpc_get_state(slpc) == SLPC_GLOBAL_STATE_RUNNING);

extra ( ) not needed

> +}
> +
> +static int guc_action_slpc_query(struct intel_guc *guc, u32 offset)
> +{
> + u32 request[] = {
> + INTEL_GUC_ACTION_SLPC_REQUEST,
> + SLPC_EVENT(SLPC_EVENT_QUERY_TASK_STATE, 2),
> + offset,
> + 0,
> + };
> + int ret;
> +
> + ret = intel_guc_send(guc, request, ARRAY_SIZE(request));
> +
> + return ret > 0 ? -EPROTO : ret;
> +}
> +
> +static int slpc_query_task_state(struct intel_guc_slpc *slpc)
> +{
> + struct intel_guc *guc = slpc_to_guc(slpc);
> + struct drm_i915_private *i915 = slpc_to_i915(slpc);
> + u32 shared_data_gtt_offset = intel_guc_ggtt_offset(guc, slpc->vma);

just "offset" ? or maybe pass directly in call below ?

> + int ret;
> +
> + ret = guc_action_slpc_query(guc, shared_data_gtt_offset);
> + if (ret)
> + drm_err(&i915->drm, "Query task state data returned (%pe)\n",

"Failed to query task state (%pe)\n" ?

> + ERR_PTR(ret));
> +
> + drm_clflush_virt_range(slpc->vaddr, SLPC_PAGE_SIZE_BYTES);
> +
> + return ret;
> +}
> +
> +static const char *slpc_global_state_to_string(enum slpc_global_state state)
> +{
> + const char *str = NULL;
> +
> + switch (state) {
> + case SLPC_GLOBAL_STATE_NOT_RUNNING:
> + str = "not running";
> + break;
> + case SLPC_GLOBAL_STATE_INITIALIZING:
> + str = "initializing";
> + break;
> + case SLPC_GLOBAL_STATE_RESETTING:
> + str = "resetting";
> + break;
> + case SLPC_GLOBAL_STATE_RUNNING:
> + str = "running";
> + break;
> + case SLPC_GLOBAL_STATE_SHUTTING_DOWN:
> + str = "shutting down";
> + break;
> + case SLPC_GLOBAL_STATE_ERROR:
> + str = "error";
> + break;
> + default:
> + str = "unknown";

nit: you can do early returns to simplify the code

> + break;
> + }
> +
> + return str;
> +}
> +
> +static const char *slpc_get_state_string(struct intel_guc_slpc *slpc)
> +{
> + return slpc_global_state_to_string(slpc_get_state(slpc));
> +}
> +
> +static int guc_action_slpc_reset(struct intel_guc *guc, u32 offset)
> +{
> + u32 request[] = {
> + INTEL_GUC_ACTION_SLPC_REQUEST,
> + SLPC_EVENT(SLPC_EVENT_RESET, 2),
> + offset,
> + 0,
> + };
> + int ret;
> +
> + ret = intel_guc_send(guc, request, ARRAY_SIZE(request));
> +
> + return ret > 0 ? -EPROTO : ret;
> +}
> +
> +static int slpc_reset(struct intel_guc_slpc *slpc)
> +{
> + struct drm_i915_private *i915 = slpc_to_i915(slpc);
> + struct intel_guc *guc = slpc_to_guc(slpc);
> + u32 offset = intel_guc_ggtt_offset(guc, slpc->vma);
> + int ret;
> +
> + ret = guc_action_slpc_reset(guc, offset);
> +
> + if (unlikely(ret < 0))
> + return ret;

no SLPC error here ?

> +
> + if (!ret) {
> + if (wait_for(slpc_is_running(slpc), SLPC_RESET_TIMEOUT_MS)) {
> + drm_err(&i915->drm, "SLPC not enabled! State = %s\n",
> + slpc_get_state_string(slpc));
> + return -EIO;
> + }
> + }
> +
> + return 0;
> +}
> +
> int intel_guc_slpc_init(struct intel_guc_slpc *slpc)
> {
> GEM_BUG_ON(slpc->vma);
> @@ -70,6 +227,86 @@ int intel_guc_slpc_init(struct intel_guc_slpc *slpc)
> return slpc_shared_data_init(slpc);
> }
>
> +static u32 slpc_decode_min_freq(struct intel_guc_slpc *slpc)
> +{
> + struct slpc_shared_data *data = slpc->vaddr;
> +
> + GEM_BUG_ON(!slpc->vma);
> +
> + return DIV_ROUND_CLOSEST(
> + REG_FIELD_GET(SLPC_MIN_UNSLICE_FREQ_MASK,
> + data->task_state_data.freq) *
> + GT_FREQUENCY_MULTIPLIER, GEN9_FREQ_SCALER);
> +}
> +
> +static u32 slpc_decode_max_freq(struct intel_guc_slpc *slpc)
> +{
> + struct slpc_shared_data *data = slpc->vaddr;
> +
> + GEM_BUG_ON(!slpc->vma);
> +
> + return DIV_ROUND_CLOSEST(
> + REG_FIELD_GET(SLPC_MAX_UNSLICE_FREQ_MASK,
> + data->task_state_data.freq) *
> + GT_FREQUENCY_MULTIPLIER, GEN9_FREQ_SCALER);
> +}
> +
> +/*
> + * intel_guc_slpc_enable() - Start SLPC
> + * @slpc: pointer to intel_guc_slpc.
> + *
> + * SLPC is enabled by setting up the shared data structure and
> + * sending reset event to GuC SLPC. Initial data is setup in
> + * intel_guc_slpc_init. Here we send the reset event. We do
> + * not currently need a slpc_disable since this is taken care
> + * of automatically when a reset/suspend occurs and the GuC
> + * CTB is destroyed.
> + *
> + * Return: 0 on success, non-zero error code on failure.
> + */
> +int intel_guc_slpc_enable(struct intel_guc_slpc *slpc)
> +{
> + struct drm_i915_private *i915 = slpc_to_i915(slpc);
> + struct slpc_shared_data *data;
> + int ret;
> +
> + GEM_BUG_ON(!slpc->vma);
> +
> + memset(slpc->vaddr, 0, sizeof(struct slpc_shared_data));
> +
> + data = slpc->vaddr;

vaddr is "struct slpc_shared_data *"
do you really need "data" local var?

> + data->header.size = sizeof(struct slpc_shared_data);
> +
> + /* Enable only GTPERF task, disable others */
> + slpc_mem_set_enabled(data, SLPC_PARAM_TASK_ENABLE_GTPERF,
> + SLPC_PARAM_TASK_DISABLE_GTPERF);
> +
> + slpc_mem_set_disabled(data, SLPC_PARAM_TASK_ENABLE_BALANCER,
> + SLPC_PARAM_TASK_DISABLE_BALANCER);
> +
> + slpc_mem_set_disabled(data, SLPC_PARAM_TASK_ENABLE_DCC,
> + SLPC_PARAM_TASK_DISABLE_DCC);

btw, all this "data" related calls are good candidate for helper like

static void slpc_shared_data_reset(struct slpc_shared_data *data)
{ ... }

> +
> + ret = slpc_reset(slpc);
> + if (unlikely(ret < 0)) {
> + drm_err(&i915->drm, "SLPC Reset event returned (%pe)\n",
> + ERR_PTR(ret));
> + return ret;
> + }
> +
> + drm_info(&i915->drm, "GuC SLPC: enabled\n");
> +
> + slpc_query_task_state(slpc);

as this still may fail, maybe it should be before we claim success and
"SLPC: enabled" ?

> +
> + /* min and max frequency limits being used by SLPC */
> + drm_info(&i915->drm, "SLPC min freq: %u Mhz, max is %u Mhz\n",
> + slpc_decode_min_freq(slpc),
> + slpc_decode_max_freq(slpc));
> +
> +
> + return 0;
> +}
> +
> void intel_guc_slpc_fini(struct intel_guc_slpc *slpc)
> {
> if (!slpc->vma)
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc_types.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc_types.h
> index edcf4c05bd9f..f14f81821a51 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc_types.h
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc_types.h
> @@ -6,6 +6,8 @@
> #ifndef _INTEL_GUC_SLPC_TYPES_H_
> #define _INTEL_GUC_SLPC_TYPES_H_
>
> +#define SLPC_RESET_TIMEOUT_MS 5
> +
> struct intel_guc_slpc {
> struct i915_vma *vma;
> struct slpc_shared_data *vaddr;
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> index e6bd9406c7b2..b98c14f8c229 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> @@ -506,6 +506,12 @@ static int __uc_init_hw(struct intel_uc *uc)
> "submission",
> enableddisabled(intel_uc_uses_guc_submission(uc)));
>
> + if (intel_uc_uses_guc_slpc(uc)) {
> + ret = intel_guc_slpc_enable(&guc->slpc);
> + if (ret)
> + goto err_submission;

hmm, as this may fail, above success message
"GuC submission enabled"
will be void

what you likely need is to split "slpc_enable" with error messages only
that is called before we start reporting successes, and then
"slpc_status" part with all drm_info() that could be placed here.

Michal

> + }
> +
> if (intel_uc_uses_huc(uc)) {
> drm_info(&i915->drm, "%s firmware %s version %u.%u %s:%s\n",
> intel_uc_fw_type_repr(INTEL_UC_FW_TYPE_HUC),
> @@ -520,6 +526,8 @@ static int __uc_init_hw(struct intel_uc *uc)
> /*
> * We've failed to load the firmware :(
> */
> +err_submission:
> + intel_guc_submission_disable(guc);
> err_log_capture:
> __uc_capture_load_err_log(uc);