On Sun, Aug 14, 2022 at 04:46:54PM -0700, Vinay Belgaumkar wrote: > Host Turbo operates at efficient frequency when GT is not idle unless > the user or workload has forced it to a higher level. Replicate the same > behavior in SLPC by allowing the algorithm to use efficient frequency. > We had disabled it during boot due to concerns that it might break > kernel ABI for min frequency. However, this is not the case since > SLPC will still abide by the (min,max) range limits. > > With this change, min freq will be at efficient frequency level at init > instead of fused min (RPn). If user chooses to reduce min freq below the > efficient freq, we will turn off usage of efficient frequency and honor > the user request. When a higher value is written, it will get toggled > back again. > > The patch also corrects the register which needs to be read for obtaining > the correct efficient frequency for Gen9+. > > We see much better perf numbers with benchmarks like glmark2 with > efficient frequency usage enabled as expected. > > BugLink: https://gitlab.freedesktop.org/drm/intel/-/issues/5468 > > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> First of all sorry for looking to the old patch first... I was delayed in my inbox flow. > Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@xxxxxxxxx> > --- > drivers/gpu/drm/i915/gt/intel_rps.c | 3 + > drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c | 66 +++++++++++---------- > drivers/gpu/drm/i915/intel_mchbar_regs.h | 3 + > 3 files changed, 40 insertions(+), 32 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c > index c7d381ad90cf..281a086fc265 100644 > --- a/drivers/gpu/drm/i915/gt/intel_rps.c > +++ b/drivers/gpu/drm/i915/gt/intel_rps.c > @@ -1108,6 +1108,9 @@ void gen6_rps_get_freq_caps(struct intel_rps *rps, struct intel_rps_freq_caps *c > } else { > caps->rp0_freq = (rp_state_cap >> 0) & 0xff; > caps->rp1_freq = (rp_state_cap >> 8) & 0xff; > + caps->rp1_freq = REG_FIELD_GET(RPE_MASK, > + intel_uncore_read(to_gt(i915)->uncore, > + GEN10_FREQ_INFO_REC)); This register is only gen10+ while the func is gen6+. either we handle the platform properly or we create a new rpe_freq tracker somewhere and if that's available we use this rpe, otherwise we use the hw fused rp1 which is a good enough, but it is not the actual one resolved by pcode, like this new RPe one. > caps->min_freq = (rp_state_cap >> 16) & 0xff; > } > > 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 e1fa1f32f29e..70a2af5f518d 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c > @@ -465,6 +465,29 @@ int intel_guc_slpc_get_max_freq(struct intel_guc_slpc *slpc, u32 *val) > return ret; > } > > +static int slpc_ignore_eff_freq(struct intel_guc_slpc *slpc, bool ignore) I know this code was already there, but I do have some questions around this and maybe we can simplify now that are touching this function. > +{ > + int ret = 0; > + > + if (ignore) { > + ret = slpc_set_param(slpc, > + SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY, > + ignore); > + if (!ret) > + return slpc_set_param(slpc, > + SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ, > + slpc->min_freq); why do we need to touch this min request here? > + } else { > + ret = slpc_unset_param(slpc, > + SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY); do we really need the unset param? for me using set_param(SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY, freq < rpe_freq) was enough... > + if (!ret) > + return slpc_unset_param(slpc, > + SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ); > + } > + > + return ret; > +} > + > /** > * intel_guc_slpc_set_min_freq() - Set min frequency limit for SLPC. > * @slpc: pointer to intel_guc_slpc. > @@ -491,6 +514,14 @@ int intel_guc_slpc_set_min_freq(struct intel_guc_slpc *slpc, u32 val) > > with_intel_runtime_pm(&i915->runtime_pm, wakeref) { > > + /* Ignore efficient freq if lower min freq is requested */ > + ret = slpc_ignore_eff_freq(slpc, val < slpc->rp1_freq); > + if (unlikely(ret)) { > + i915_probe_error(i915, "Failed to toggle efficient freq (%pe)\n", > + ERR_PTR(ret)); > + return ret; > + } > + > ret = slpc_set_param(slpc, > SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ, > val); > @@ -587,7 +618,9 @@ static int slpc_set_softlimits(struct intel_guc_slpc *slpc) > return ret; > > if (!slpc->min_freq_softlimit) { > - slpc->min_freq_softlimit = slpc->min_freq; > + ret = intel_guc_slpc_get_min_freq(slpc, &slpc->min_freq_softlimit); > + if (unlikely(ret)) > + return ret; > slpc_to_gt(slpc)->defaults.min_freq = slpc->min_freq_softlimit; > } else if (slpc->min_freq_softlimit != slpc->min_freq) { > return intel_guc_slpc_set_min_freq(slpc, > @@ -597,29 +630,6 @@ static int slpc_set_softlimits(struct intel_guc_slpc *slpc) > return 0; > } > > -static int slpc_ignore_eff_freq(struct intel_guc_slpc *slpc, bool ignore) > -{ > - int ret = 0; > - > - if (ignore) { > - ret = slpc_set_param(slpc, > - SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY, > - ignore); > - if (!ret) > - return slpc_set_param(slpc, > - SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ, > - slpc->min_freq); > - } else { > - ret = slpc_unset_param(slpc, > - SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY); > - if (!ret) > - return slpc_unset_param(slpc, > - SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ); > - } > - > - return ret; > -} > - > static int slpc_use_fused_rp0(struct intel_guc_slpc *slpc) > { > /* Force SLPC to used platform rp0 */ > @@ -679,14 +689,6 @@ int intel_guc_slpc_enable(struct intel_guc_slpc *slpc) > > slpc_get_rp_values(slpc); > > - /* Ignore efficient freq and set min to platform min */ > - ret = slpc_ignore_eff_freq(slpc, true); > - if (unlikely(ret)) { > - i915_probe_error(i915, "Failed to set SLPC min to RPn (%pe)\n", > - ERR_PTR(ret)); > - return ret; > - } > - > /* Set SLPC max limit to RP0 */ > ret = slpc_use_fused_rp0(slpc); > if (unlikely(ret)) { > diff --git a/drivers/gpu/drm/i915/intel_mchbar_regs.h b/drivers/gpu/drm/i915/intel_mchbar_regs.h > index 2aad2f0cc8db..ffc702b79579 100644 > --- a/drivers/gpu/drm/i915/intel_mchbar_regs.h > +++ b/drivers/gpu/drm/i915/intel_mchbar_regs.h > @@ -196,6 +196,9 @@ > #define RP1_CAP_MASK REG_GENMASK(15, 8) > #define RPN_CAP_MASK REG_GENMASK(23, 16) > > +#define GEN10_FREQ_INFO_REC _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5ef0) > +#define RPE_MASK REG_GENMASK(15, 8) > + > /* snb MCH registers for priority tuning */ > #define MCH_SSKPD _MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5d10) > #define SSKPD_NEW_WM0_MASK_HSW REG_GENMASK64(63, 56) > -- > 2.35.1 >
