Default SLPC power profile is Base(0). Power Saving mode(1)
has conservative up/down thresholds and is suitable for use with
apps that typically need to be power efficient.

Selected power profile will be displayed in this format-

$ cat slpc_power_profile

  [base]    power_saving

$ echo power_saving > slpc_power_profile
$ cat slpc_power_profile

  base    [power_saving]

v2: Disable waitboost in power saving profile, update sysfs
format and add some kernel doc for SLPC (Rodrigo)

v3: Update doc with info about power profiles (Rodrigo)

v4: Checkpatch warning and remove extra line (Rodrigo)

Cc: Sushma Venkatesh Reddy <sushma.venkatesh.re...@intel.com>
Cc: Rodrigo Vivi <rodrigo.v...@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.v...@intel.com>
Signed-off-by: Vinay Belgaumkar <vinay.belgaum...@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c   | 47 ++++++++++++++
 drivers/gpu/drm/i915/gt/intel_rps.c           |  4 ++
 .../drm/i915/gt/uc/abi/guc_actions_slpc_abi.h |  5 ++
 drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c   | 65 +++++++++++++++++++
 drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h   |  1 +
 .../gpu/drm/i915/gt/uc/intel_guc_slpc_types.h |  3 +
 6 files changed, 125 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c 
b/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
index d7784650e4d9..1154cd2b7c34 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_sysfs_pm.c
@@ -464,6 +464,45 @@ static ssize_t slpc_ignore_eff_freq_store(struct kobject 
*kobj,
        return err ?: count;
 }
 
+static ssize_t slpc_power_profile_show(struct kobject *kobj,
+                                      struct kobj_attribute *attr,
+                                      char *buff)
+{
+       struct intel_gt *gt = intel_gt_sysfs_get_drvdata(kobj, attr->attr.name);
+       struct intel_guc_slpc *slpc = &gt->uc.guc.slpc;
+
+       switch (slpc->power_profile) {
+       case SLPC_POWER_PROFILES_BASE:
+               return sysfs_emit(buff, "[%s]    %s\n", "base", "power_saving");
+       case SLPC_POWER_PROFILES_POWER_SAVING:
+               return sysfs_emit(buff, "%s    [%s]\n", "base", "power_saving");
+       }
+
+       return sysfs_emit(buff, "%u\n", slpc->power_profile);
+}
+
+static ssize_t slpc_power_profile_store(struct kobject *kobj,
+                                       struct kobj_attribute *attr,
+                                       const char *buff, size_t count)
+{
+       struct intel_gt *gt = intel_gt_sysfs_get_drvdata(kobj, attr->attr.name);
+       struct intel_guc_slpc *slpc = &gt->uc.guc.slpc;
+       char power_saving[] = "power_saving";
+       char base[] = "base";
+       int err;
+       u32 val;
+
+       if (!strncmp(buff, power_saving, sizeof(power_saving) - 1))
+               val = SLPC_POWER_PROFILES_POWER_SAVING;
+       else if (!strncmp(buff, base, sizeof(base) - 1))
+               val = SLPC_POWER_PROFILES_BASE;
+       else
+               return -EINVAL;
+
+       err = intel_guc_slpc_set_power_profile(slpc, val);
+       return err ?: count;
+}
+
 struct intel_gt_bool_throttle_attr {
        struct attribute attr;
        ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
@@ -668,6 +707,7 @@ INTEL_GT_ATTR_RO(media_RP0_freq_mhz);
 INTEL_GT_ATTR_RO(media_RPn_freq_mhz);
 
 INTEL_GT_ATTR_RW(slpc_ignore_eff_freq);
+INTEL_GT_ATTR_RW(slpc_power_profile);
 
 static const struct attribute *media_perf_power_attrs[] = {
        &attr_media_freq_factor.attr,
@@ -864,6 +904,13 @@ void intel_gt_sysfs_pm_init(struct intel_gt *gt, struct 
kobject *kobj)
                        gt_warn(gt, "failed to create ignore_eff_freq sysfs 
(%pe)", ERR_PTR(ret));
        }
 
+       if (intel_uc_uses_guc_slpc(&gt->uc)) {
+               ret = sysfs_create_file(kobj, &attr_slpc_power_profile.attr);
+               if (ret)
+                       gt_warn(gt, "failed to create slpc_power_profile sysfs 
(%pe)",
+                               ERR_PTR(ret));
+       }
+
        if (i915_mmio_reg_valid(intel_gt_perf_limit_reasons_reg(gt))) {
                ret = sysfs_create_files(kobj, throttle_reason_attrs);
                if (ret)
diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c 
b/drivers/gpu/drm/i915/gt/intel_rps.c
index fa304ea088e4..2cfaedb04876 100644
--- a/drivers/gpu/drm/i915/gt/intel_rps.c
+++ b/drivers/gpu/drm/i915/gt/intel_rps.c
@@ -1025,6 +1025,10 @@ void intel_rps_boost(struct i915_request *rq)
                if (rps_uses_slpc(rps)) {
                        slpc = rps_to_slpc(rps);
 
+                       /* Waitboost should not be done with power saving 
profile */
+                       if (slpc->power_profile == 
SLPC_POWER_PROFILES_POWER_SAVING)
+                               return;
+
                        if (slpc->min_freq_softlimit >= slpc->boost_freq)
                                return;
 
diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_slpc_abi.h 
b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_slpc_abi.h
index c34674e797c6..6de87ae5669e 100644
--- a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_slpc_abi.h
+++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_slpc_abi.h
@@ -228,6 +228,11 @@ struct slpc_optimized_strategies {
 
 #define SLPC_OPTIMIZED_STRATEGY_COMPUTE                REG_BIT(0)
 
+enum slpc_power_profiles {
+       SLPC_POWER_PROFILES_BASE = 0x0,
+       SLPC_POWER_PROFILES_POWER_SAVING = 0x1
+};
+
 /**
  * DOC: SLPC H2G MESSAGE FORMAT
  *
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 706fffca698b..e6e373cb5da8 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
@@ -15,6 +15,34 @@
 #include "gt/intel_gt_regs.h"
 #include "gt/intel_rps.h"
 
+/**
+ * DOC: SLPC - Dynamic Frequency management
+ *
+ * Single Loop Power Control (SLPC) is a GuC algorithm that manages
+ * GT frequency based on busyness and how KMD initializes it. SLPC is
+ * almost completely in control after initialization except for a few
+ * scenarios mentioned below.
+ *
+ * KMD uses the concept of waitboost to ramp frequency to RP0 when there
+ * are pending submissions for a context. It achieves this by sending GuC a
+ * request to update the min frequency to RP0. Waitboost is disabled
+ * when the request retires.
+ *
+ * Another form of frequency control happens through per-context hints.
+ * A context can be marked as low latency during creation. That will ensure
+ * that SLPC uses an aggressive frequency ramp when that context is active.
+ *
+ * Power profiles add another level of control to these mechanisms.
+ * When power saving profile is chosen, SLPC will use conservative
+ * thresholds to ramp frequency, thus saving power. KMD will disable
+ * waitboosts as well, which achieves further power savings. Base profile
+ * is default and ensures balanced performance for any workload.
+ *
+ * Lastly, users have some level of control through sysfs, where min/max
+ * frequency values can be altered and the use of efficient freq
+ * can be toggled.
+ */
+
 static inline struct intel_guc *slpc_to_guc(struct intel_guc_slpc *slpc)
 {
        return container_of(slpc, struct intel_guc, slpc);
@@ -265,6 +293,8 @@ int intel_guc_slpc_init(struct intel_guc_slpc *slpc)
        slpc->num_boosts = 0;
        slpc->media_ratio_mode = SLPC_MEDIA_RATIO_MODE_DYNAMIC_CONTROL;
 
+       slpc->power_profile = SLPC_POWER_PROFILES_BASE;
+
        mutex_init(&slpc->lock);
        INIT_WORK(&slpc->boost_work, slpc_boost_work);
 
@@ -567,6 +597,34 @@ int intel_guc_slpc_set_media_ratio_mode(struct 
intel_guc_slpc *slpc, u32 val)
        return ret;
 }
 
+int intel_guc_slpc_set_power_profile(struct intel_guc_slpc *slpc, u32 val)
+{
+       struct drm_i915_private *i915 = slpc_to_i915(slpc);
+       intel_wakeref_t wakeref;
+       int ret = 0;
+
+       if (val > SLPC_POWER_PROFILES_POWER_SAVING)
+               return -EINVAL;
+
+       mutex_lock(&slpc->lock);
+       wakeref = intel_runtime_pm_get(&i915->runtime_pm);
+
+       ret = slpc_set_param(slpc,
+                            SLPC_PARAM_POWER_PROFILE,
+                            val);
+       if (ret)
+               guc_err(slpc_to_guc(slpc),
+                       "Failed to set power profile to %d: %pe\n",
+                        val, ERR_PTR(ret));
+       else
+               slpc->power_profile = val;
+
+       intel_runtime_pm_put(&i915->runtime_pm, wakeref);
+       mutex_unlock(&slpc->lock);
+
+       return ret;
+}
+
 void intel_guc_pm_intrmsk_enable(struct intel_gt *gt)
 {
        u32 pm_intrmsk_mbz = 0;
@@ -728,6 +786,13 @@ int intel_guc_slpc_enable(struct intel_guc_slpc *slpc)
        /* Enable SLPC Optimized Strategy for compute */
        intel_guc_slpc_set_strategy(slpc, SLPC_OPTIMIZED_STRATEGY_COMPUTE);
 
+       /* Set cached value of power_profile */
+       ret = intel_guc_slpc_set_power_profile(slpc, slpc->power_profile);
+       if (unlikely(ret)) {
+               guc_probe_error(guc, "Failed to set SLPC power profile: %pe\n", 
ERR_PTR(ret));
+               return ret;
+       }
+
        return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h 
b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h
index 1cb5fd44f05c..fc9f761b4372 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h
@@ -46,5 +46,6 @@ void intel_guc_slpc_boost(struct intel_guc_slpc *slpc);
 void intel_guc_slpc_dec_waiters(struct intel_guc_slpc *slpc);
 int intel_guc_slpc_set_ignore_eff_freq(struct intel_guc_slpc *slpc, bool val);
 int intel_guc_slpc_set_strategy(struct intel_guc_slpc *slpc, u32 val);
+int intel_guc_slpc_set_power_profile(struct intel_guc_slpc *slpc, u32 val);
 
 #endif
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 a88651331497..83673b10ac4e 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
@@ -33,6 +33,9 @@ struct intel_guc_slpc {
        u32 max_freq_softlimit;
        bool ignore_eff_freq;
 
+       /* Base or power saving */
+       u32 power_profile;
+
        /* cached media ratio mode */
        u32 media_ratio_mode;
 
-- 
2.38.1

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