drm/i915/guc/slpc: Cache platform frequency limits

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)
v3: Formatting (Michal W)
v4: Add separate function to parse rp values (Michal W)
v5: Perform range checking for set min/max (Michal W)
v6: checkpatch() and rename static functions (Michal W)
v7: check ret code while setting SLPC limits (Michal W)

Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730202119.23810-12-vinay.belgaumkar@intel.com

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 ebabc84d4e39472150d19eba5af6519c0f5a016e..65a3e7fdb2b2cb118124c350683fc2a9595e5ce4 100644 (file)
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
@@ -96,6 +96,9 @@ int intel_guc_slpc_init(struct intel_guc_slpc *slpc)
                return err;
        }
 
+       slpc->max_freq_softlimit = 0;
+       slpc->min_freq_softlimit = 0;
+
        return err;
 }
 
@@ -126,6 +129,17 @@ static int guc_action_slpc_set_param(struct intel_guc *guc, u8 id, u32 value)
        return ret > 0 ? -EPROTO : ret;
 }
 
+static int guc_action_slpc_unset_param(struct intel_guc *guc, u8 id)
+{
+       u32 request[] = {
+               GUC_ACTION_HOST2GUC_PC_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;
@@ -179,6 +193,16 @@ static int slpc_set_param(struct intel_guc_slpc *slpc, u8 id, u32 value)
        return ret;
 }
 
+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_global_state_to_string(enum slpc_global_state state)
 {
        switch (state) {
@@ -300,6 +324,11 @@ int intel_guc_slpc_set_max_freq(struct intel_guc_slpc *slpc, u32 val)
        intel_wakeref_t wakeref;
        int ret;
 
+       if (val < slpc->min_freq ||
+           val > slpc->rp0_freq ||
+           val < slpc->min_freq_softlimit)
+               return -EINVAL;
+
        with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
                ret = slpc_set_param(slpc,
                                     SLPC_PARAM_GLOBAL_MAX_GT_UNSLICE_FREQ_MHZ,
@@ -310,6 +339,9 @@ int intel_guc_slpc_set_max_freq(struct intel_guc_slpc *slpc, u32 val)
                        ret = -EIO;
        }
 
+       if (!ret)
+               slpc->max_freq_softlimit = val;
+
        return ret;
 }
 
@@ -356,6 +388,11 @@ int intel_guc_slpc_set_min_freq(struct intel_guc_slpc *slpc, u32 val)
        intel_wakeref_t wakeref;
        int ret;
 
+       if (val < slpc->min_freq ||
+           val > slpc->rp0_freq ||
+           val > slpc->max_freq_softlimit)
+               return -EINVAL;
+
        with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
                ret = slpc_set_param(slpc,
                                     SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ,
@@ -366,6 +403,9 @@ int intel_guc_slpc_set_min_freq(struct intel_guc_slpc *slpc, u32 val)
                        ret = -EIO;
        }
 
+       if (!ret)
+               slpc->min_freq_softlimit = val;
+
        return ret;
 }
 
@@ -411,6 +451,79 @@ void intel_guc_pm_intrmsk_enable(struct intel_gt *gt)
                         GEN6_PMINTRMSK, pm_intrmsk_mbz, 0);
 }
 
+static int 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 (unlikely(ret))
+               return ret;
+
+       if (!slpc->min_freq_softlimit)
+               slpc->min_freq_softlimit = slpc->min_freq;
+       else if (slpc->min_freq_softlimit != slpc->min_freq)
+               return intel_guc_slpc_set_min_freq(slpc,
+                                                  slpc->min_freq_softlimit);
+
+       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 */
+       return slpc_set_param(slpc,
+                             SLPC_PARAM_GLOBAL_MAX_GT_UNSLICE_FREQ_MHZ,
+                             slpc->rp0_freq);
+}
+
+static void slpc_get_rp_values(struct intel_guc_slpc *slpc)
+{
+       u32 rp_state_cap;
+
+       rp_state_cap = intel_uncore_read(slpc_to_gt(slpc)->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;
+}
+
 /*
  * intel_guc_slpc_enable() - Start SLPC
  * @slpc: pointer to intel_guc_slpc.
@@ -446,6 +559,32 @@ int intel_guc_slpc_enable(struct intel_guc_slpc *slpc)
 
        intel_guc_pm_intrmsk_enable(&i915->gt);
 
+       slpc_get_rp_values(slpc);
+
+       /* Ignore efficient freq and set min to platform min */
+       ret = slpc_ignore_eff_freq(slpc, true);
+       if (unlikely(ret)) {
+               drm_err(&i915->drm, "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)) {
+               drm_err(&i915->drm, "Failed to set SLPC max to RP0 (%pe)\n",
+                       ERR_PTR(ret));
+               return ret;
+       }
+
+       /* Revert SLPC min/max to softlimits if necessary */
+       ret = slpc_set_softlimits(slpc);
+       if (unlikely(ret)) {
+               drm_err(&i915->drm, "Failed to set SLPC softlimits (%pe)\n",
+                       ERR_PTR(ret));
+               return ret;
+       }
+
        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 3cefe19b17b2fd8e132cab51b55aa0307bb27591..41d13527666f6c7a607d8ee16c28b4cc8cb1f5e3 100644 (file)
--- 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 slpc_shared_data *vaddr;
        bool supported;
        bool selected;
+
+       /* 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 5603377e06cace94ca9037c10fc77317e7046832..f3a445f79a3645a5a67db2c2c90f24f4afa4f6d2 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4109,6 +4109,9 @@ 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)