| Message ID | 20220814234654.34800-1-vinay.belgaumkar@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/guc/slpc: Allow SLPC to use efficient frequency | expand |
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@intel.com> 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@intel.com> > --- > 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 >
On Sun, 14 Aug 2022 16:46:54 -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. This change seems to have broken the i915 kernel ABI for min frequency for DG2. Tvrtko pointed this out here: https://patchwork.freedesktop.org/patch/512274/?series=110574&rev=3 These bugs are the result of that ABI break: Bug: https://gitlab.freedesktop.org/drm/intel/-/issues/6806 Bug: https://gitlab.freedesktop.org/drm/intel/-/issues/6786 On DG2 when we set min == max freq, we see the GPU running not at the set min == max freq but at efficient freq (different from the set freq). We are still trying to see if the ABI can be salvaged but something is definitely wrong at present. Thanks. -- Ashutosh
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)); 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) +{ + 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; +} + /** * 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)
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@intel.com> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com> --- 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(-)