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

Vinay Belgaumkar
2021-07-21T16:12:46Z

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)
+{
+ 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);
+ }
+}
+
+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",
+ ERR_PTR(ret));
+
+ 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)

--
2.25.0