[Intel-gfx] [PATCH 3/6] drm/i915: Add uncore mmio api for per-context registers
Robert Bragg
robert at sixbynine.org
Wed Feb 22 16:36:31 UTC 2017
Since the exponent for periodic OA counter sampling is maintained in a
per-context register while we want to treat it as if it were global
state we need to be able to safely issue an mmio write to a per-context
register and affect any currently running context.
We have to take some extra care in this case and this adds a utility
api to encapsulate what's required.
Signed-off-by: Robert Bragg <robert at sixbynine.org>
---
drivers/gpu/drm/i915/i915_drv.h | 4 ++
drivers/gpu/drm/i915/i915_reg.h | 3 ++
drivers/gpu/drm/i915/intel_uncore.c | 73 +++++++++++++++++++++++++++++++++++++
3 files changed, 80 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 105b97bd34d7..c8d03a2e89cc 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -718,6 +718,7 @@ intel_uncore_forcewake_for_reg(struct drm_i915_private *dev_priv,
i915_reg_t reg, unsigned int op);
struct intel_uncore_funcs {
+ int (*wait_for_rcs_busy)(struct drm_i915_private *dev_priv);
void (*force_wake_get)(struct drm_i915_private *dev_priv,
enum forcewake_domains domains);
void (*force_wake_put)(struct drm_i915_private *dev_priv,
@@ -751,6 +752,7 @@ struct intel_uncore {
struct intel_uncore_funcs funcs;
+ atomic_t hold_rcs_busy_count;
unsigned fifo_count;
enum forcewake_domains fw_domains;
@@ -3139,6 +3141,8 @@ static inline bool intel_vgpu_active(struct drm_i915_private *dev_priv)
{
return dev_priv->vgpu.active;
}
+int intel_uncore_begin_ctx_mmio(struct drm_i915_private *dev_priv);
+void intel_uncore_end_ctx_mmio(struct drm_i915_private *dev_priv);
void
i915_enable_pipestat(struct drm_i915_private *dev_priv, enum pipe pipe,
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 141a5c1e3895..94d40e82edc1 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2313,6 +2313,9 @@ enum skl_disp_power_wells {
#define GEN8_RC_SEMA_IDLE_MSG_DISABLE (1 << 12)
#define GEN8_FF_DOP_CLOCK_GATE_DISABLE (1<<10)
+#define GEN6_RCS_PWR_FSM _MMIO(0x22ac)
+#define GEN9_RCS_FE_FSM2 _MMIO(0x22a4)
+
/* Fuse readout registers for GT */
#define CHV_FUSE_GT _MMIO(VLV_DISPLAY_BASE + 0x2168)
#define CHV_FGT_DISABLE_SS0 (1 << 10)
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 441c51fd9746..06bfe5f89ac5 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1274,6 +1274,16 @@ static void intel_uncore_fw_domains_init(struct drm_i915_private *dev_priv)
WARN_ON(dev_priv->uncore.fw_domains == 0);
}
+static int gen8_wait_for_rcs_busy(struct drm_i915_private *dev_priv)
+{
+ return wait_for((I915_READ(GEN6_RCS_PWR_FSM) & 0x3f) == 0x30, 50);
+}
+
+static int gen9_wait_for_rcs_busy(struct drm_i915_private *dev_priv)
+{
+ return wait_for((I915_READ(GEN9_RCS_FE_FSM2) & 0x3f) == 0x30, 50);
+}
+
#define ASSIGN_FW_DOMAINS_TABLE(d) \
{ \
dev_priv->uncore.fw_domains_table = \
@@ -1305,6 +1315,8 @@ void intel_uncore_init(struct drm_i915_private *dev_priv)
dev_priv->uncore.funcs.mmio_writel =
gen9_decoupled_write32;
}
+ dev_priv->uncore.funcs.wait_for_rcs_busy =
+ gen9_wait_for_rcs_busy;
break;
case 8:
if (IS_CHERRYVIEW(dev_priv)) {
@@ -1316,6 +1328,8 @@ void intel_uncore_init(struct drm_i915_private *dev_priv)
ASSIGN_WRITE_MMIO_VFUNCS(gen8);
ASSIGN_READ_MMIO_VFUNCS(gen6);
}
+ dev_priv->uncore.funcs.wait_for_rcs_busy =
+ gen8_wait_for_rcs_busy;
break;
case 7:
case 6:
@@ -1858,6 +1872,65 @@ intel_uncore_forcewake_for_reg(struct drm_i915_private *dev_priv,
return fw_domains;
}
+static int hold_rcs_busy(struct drm_i915_private *dev_priv)
+{
+ int ret = 0;
+
+ if (atomic_inc_and_test(&dev_priv->uncore.hold_rcs_busy_count)) {
+ I915_WRITE(GEN6_RC_SLEEP_PSMI_CONTROL,
+ _MASKED_BIT_ENABLE(GEN6_PSMI_SLEEP_MSG_DISABLE));
+
+ ret = dev_priv->uncore.funcs.wait_for_rcs_busy(dev_priv);
+ }
+
+ return ret;
+}
+
+static void release_rcs_busy(struct drm_i915_private *dev_priv)
+{
+ if (!atomic_dec_and_test(&dev_priv->uncore.hold_rcs_busy_count)) {
+ I915_WRITE(GEN6_RC_SLEEP_PSMI_CONTROL,
+ _MASKED_BIT_DISABLE(GEN6_PSMI_SLEEP_MSG_DISABLE));
+ }
+}
+
+/*
+ * From Broadwell PRM, 3D-Media-GPGPU -> Register State Context
+ *
+ * MMIO reads or writes to any of the registers listed in the
+ * “Register State Context image” subsections through HOST/IA
+ * MMIO interface for debug purposes must follow the steps below:
+ *
+ * - SW should set the Force Wakeup bit to prevent GT from entering C6.
+ * - Write 0x2050[31:0] = 0x00010001 (disable sequence).
+ * - Disable IDLE messaging in CS (Write 0x2050[31:0] = 0x00010001).
+ * - BDW: Poll/Wait for register bits of 0x22AC[6:0] turn to 0x30 value.
+ * - SKL+: Poll/Wait for register bits of 0x22A4[6:0] turn to 0x30 value.
+ * - Read/Write to desired MMIO registers.
+ * - Enable IDLE messaging in CS (Write 0x2050[31:0] = 0x00010000).
+ * - Force Wakeup bit should be reset to enable C6 entry.
+ */
+int intel_uncore_begin_ctx_mmio(struct drm_i915_private *dev_priv)
+{
+ int ret = 0;
+
+ BUG_ON(dev_priv->info.gen < 8);
+
+ intel_uncore_forcewake_get(dev_priv, FORCEWAKE_RENDER);
+
+ ret = hold_rcs_busy(dev_priv);
+ if (ret)
+ intel_uncore_forcewake_put(dev_priv, FORCEWAKE_RENDER);
+
+ return ret;
+}
+
+void intel_uncore_end_ctx_mmio(struct drm_i915_private *dev_priv)
+{
+ release_rcs_busy(dev_priv);
+ intel_uncore_forcewake_put(dev_priv, FORCEWAKE_RENDER);
+}
+
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftests/intel_uncore.c"
#endif
--
2.11.1
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