Re: [Intel-gfx] [PATCH 11/14] drm/i915/guc/slpc: Cache platform frequency limits

Michal Wajdeczko
2021-07-21T18:09:44Z

On 21.07.2021 18:11, Vinay Belgaumkar wrote:
> Cache rp0, rp1 and rpn platform limits into SLPC structure
> for range checking while setting min/max frequencies.
>
> Also add "soft" limits which keep track of frequency changes
> made from userland. These are initially set to platform min
> and max.
>
> v2: Address review comments (Michal W)
>
> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
> ---
> drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c | 98 +++++++++++++++++++
> .../gpu/drm/i915/gt/uc/intel_guc_slpc_types.h | 9 ++
> drivers/gpu/drm/i915/i915_reg.h | 3 +
> 3 files changed, 110 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 8796a8929d89..134c57ca10b7 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
> @@ -94,6 +94,9 @@ static int slpc_shared_data_init(struct intel_guc_slpc *slpc)
> return err;
> }
>
> + slpc->max_freq_softlimit = 0;
> + slpc->min_freq_softlimit = 0;
> +
> return err;
> }
>
> @@ -121,6 +124,19 @@ static int guc_action_slpc_set_param(struct intel_guc *guc, u8 id, u32 value)
> return intel_guc_send(guc, request, ARRAY_SIZE(request));
> }
>
> +static int guc_action_slpc_unset_param(struct intel_guc *guc,
> + u8 id)
> +{
> + u32 request[] = {
> + INTEL_GUC_ACTION_SLPC_REQUEST,
> + SLPC_EVENT(SLPC_EVENT_PARAMETER_UNSET, 2),
> + id,
> + };
> +
> + return intel_guc_send(guc, request, ARRAY_SIZE(request));
> +}
> +
> +
> static bool slpc_is_running(struct intel_guc_slpc *slpc)
> {
> return (slpc_get_state(slpc) == SLPC_GLOBAL_STATE_RUNNING);
> @@ -164,6 +180,16 @@ static int slpc_set_param(struct intel_guc_slpc *slpc, u8 id, u32 value)
> return guc_action_slpc_set_param(guc, id, value);
> }
>
> +static int slpc_unset_param(struct intel_guc_slpc *slpc,
> + u8 id)

likely can fit into one line

> +{
> + struct intel_guc *guc = slpc_to_guc(slpc);
> +
> + GEM_BUG_ON(id >= SLPC_MAX_PARAM);
> +
> + return guc_action_slpc_unset_param(guc, id);
> +}
> +
> static const char *slpc_state_string(struct intel_guc_slpc *slpc)
> {
> const char *str = NULL;
> @@ -388,6 +414,55 @@ void intel_guc_pm_intrmsk_enable(struct intel_gt *gt)
> GEN6_PMINTRMSK, pm_intrmsk_mbz, 0);
> }
>
> +static int intel_guc_slpc_set_softlimits(struct intel_guc_slpc *slpc)
> +{
> + int ret = 0;
> +
> + /* Softlimits are initially equivalent to platform limits
> + * unless they have deviated from defaults, in which case,
> + * we retain the values and set min/max accordingly.
> + */
> + if (!slpc->max_freq_softlimit)
> + slpc->max_freq_softlimit = slpc->rp0_freq;
> + else if (slpc->max_freq_softlimit != slpc->rp0_freq)
> + ret = intel_guc_slpc_set_max_freq(slpc,
> + slpc->max_freq_softlimit);
> +
> + if (!slpc->min_freq_softlimit)
> + slpc->min_freq_softlimit = slpc->min_freq;
> + else if (slpc->min_freq_softlimit != slpc->min_freq)
> + ret = intel_guc_slpc_set_min_freq(slpc,
> + slpc->min_freq_softlimit);
> +
> + return ret;
> +}
> +
> +static void intel_guc_slpc_ignore_eff_freq(struct intel_guc_slpc *slpc, bool ignore)
> +{
> + if (ignore) {
> + /* A failure here does not affect the algorithm in a fatal way */
> + slpc_set_param(slpc,
> + SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY,
> + ignore);
> + slpc_set_param(slpc,
> + SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ,
> + slpc->min_freq);
> + } else {
> + slpc_unset_param(slpc,
> + SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY);
> + slpc_unset_param(slpc,
> + SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ);

hard to tell from mail client, but likely misalignment
did you run checkpatch.pl ?

> + }
> +}
> +
> +static void intel_guc_slpc_use_fused_rp0(struct intel_guc_slpc *slpc)
> +{
> + /* Force slpc to used platform rp0 */
> + slpc_set_param(slpc,
> + SLPC_PARAM_GLOBAL_MAX_GT_UNSLICE_FREQ_MHZ,
> + slpc->rp0_freq);
> +}
> +
> /*
> * intel_guc_slpc_enable() - Start SLPC
> * @slpc: pointer to intel_guc_slpc.
> @@ -405,6 +480,7 @@ int intel_guc_slpc_enable(struct intel_guc_slpc *slpc)
> {
> struct drm_i915_private *i915 = slpc_to_i915(slpc);
> struct slpc_shared_data *data;
> + u32 rp_state_cap;
> int ret;
>
> GEM_BUG_ON(!slpc->vma);
> @@ -442,6 +518,28 @@ int intel_guc_slpc_enable(struct intel_guc_slpc *slpc)
> slpc_decode_min_freq(slpc),
> slpc_decode_max_freq(slpc));
>
> + rp_state_cap = intel_uncore_read(i915->gt.uncore, GEN6_RP_STATE_CAP);
> +
> + slpc->rp0_freq = REG_FIELD_GET(RP0_CAP_MASK, rp_state_cap) *
> + GT_FREQUENCY_MULTIPLIER;
> + slpc->rp1_freq = REG_FIELD_GET(RP1_CAP_MASK, rp_state_cap) *
> + GT_FREQUENCY_MULTIPLIER;
> + slpc->min_freq = REG_FIELD_GET(RPN_CAP_MASK, rp_state_cap) *
> + GT_FREQUENCY_MULTIPLIER;
> +
> + /* Ignore efficient freq and set min/max to platform min/max */
> + intel_guc_slpc_ignore_eff_freq(slpc, true);
> + intel_guc_slpc_use_fused_rp0(slpc);
> +
> + ret = intel_guc_slpc_set_softlimits(slpc);
> + if (ret)
> + drm_err(&i915->drm, "Set softlimits returned (%pe)\n",

"Failed to set SLPC softlimits (%pe)\n"

> + ERR_PTR(ret));

should we continue after error ?

Michal

> +
> + drm_info(&i915->drm,
> + "Platform fused frequency values - min: %u Mhz, max: %u Mhz\n",
> + slpc->min_freq,
> + slpc->rp0_freq);
>
> return 0;
> }
> 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 c417992b1346..8c42562a28fc 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
> @@ -15,6 +15,15 @@ struct intel_guc_slpc {
>
> struct i915_vma *vma;
> struct slpc_shared_data *vaddr;
> +
> + /* platform frequency limits */
> + u32 min_freq;
> + u32 rp0_freq;
> + u32 rp1_freq;
> +
> + /* frequency softlimits */
> + u32 min_freq_softlimit;
> + u32 max_freq_softlimit;
> };
>
> #endif
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index aa433ae8f5de..92392c1da0e6 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4086,6 +4086,9 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
> #define BXT_GT_PERF_STATUS _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x7070)
> #define GEN6_RP_STATE_LIMITS _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5994)
> #define GEN6_RP_STATE_CAP _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5998)
> +#define RP0_CAP_MASK REG_GENMASK(7, 0)
> +#define RP1_CAP_MASK REG_GENMASK(15, 8)
> +#define RPN_CAP_MASK REG_GENMASK(23, 16)
> #define BXT_RP_STATE_CAP _MMIO(0x138170)
> #define GEN9_RP_STATE_LIMITS _MMIO(0x138148)
>
>