[PATCH v11 5/6] drm/i915/guc: Check the locking status of GuC WOPCM registers
Jackie Li
yaodong.li at intel.com
Wed Feb 28 22:32:41 UTC 2018
GuC WOPCM registers are write-once registers. Current driver code accesses
these registers without checking the accessibility to these registers which
will lead to unpredictable driver behaviors if these registers were touch
by other components (such as faulty BIOS code).
This patch moves the GuC WOPCM registers updating code into
intel_guc_wopcm.c and adds check before and after the update to GuC WOPCM
registers so that we can make sure the driver is in a known state before
and after writing to these write-once registers.
v6:
- Made sure module reloading won't bug the kernel while doing
locking status checking
v7:
- Fixed patch format issues
v8:
- Fixed coding style issue on register lock bit macro definition (Sagar)
v9:
- Avoided to use redundant !! to cast uint to bool (Chris)
- Return error code instead of GEM_BUG_ON for locked with invalid register
values case (Sagar)
- Updated guc_wopcm_hw_init to use guc_wopcm as first parameter (Michal)
- Added code to set and validate the HuC_LOADING_AGENT_GUC bit in GuC
WOPCM offset register based on the presence of HuC firmware (Michal)
- Use bit fields instead of macros for GuC WOPCM flags (Michal)
v10:
- Refined variable names, removed redundant comments (Joonas)
- Introduced lockable_reg to handle the write once register write and
propagate the write error to caller (Joonas)
- Used lockable_reg abstraction to avoid locking bit check on generic
i915_reg_t (Michal)
- Added log message for error paths (Michal)
- Removed hw_updated flag and only relies on real hardware status
v11:
- Replaced lockable_reg with simplified function (Michal)
- Used new macros for locking bits of WOPCM size/offset registers instead
of using BIT(0) directly (Michal)
- use intel_wopcm_init_hw() called from intel_gem_init_hw() to do GuC
WOPCM register setup instead of calling from intel_uc_init_hw() (Michal)
BSpec: 10875, 10833
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Signed-off-by: Jackie Li <yaodong.li at intel.com>
---
drivers/gpu/drm/i915/i915_gem.c | 6 ++++
drivers/gpu/drm/i915/intel_guc_reg.h | 3 ++
drivers/gpu/drm/i915/intel_uc.c | 5 ----
drivers/gpu/drm/i915/intel_wopcm.c | 58 ++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_wopcm.h | 1 +
5 files changed, 68 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d31ad0b..662d670 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5122,6 +5122,12 @@ int i915_gem_init_hw(struct drm_i915_private *dev_priv)
goto out;
}
+ ret = intel_wopcm_init_hw(&dev_priv->wopcm);
+ if (ret) {
+ DRM_ERROR("Enabling WOPCM failed (%d)\n", ret);
+ goto out;
+ }
+
/* We can't enable contexts until all firmware is loaded */
ret = intel_uc_init_hw(dev_priv);
if (ret) {
diff --git a/drivers/gpu/drm/i915/intel_guc_reg.h b/drivers/gpu/drm/i915/intel_guc_reg.h
index 01963d0..d860847 100644
--- a/drivers/gpu/drm/i915/intel_guc_reg.h
+++ b/drivers/gpu/drm/i915/intel_guc_reg.h
@@ -66,15 +66,18 @@
#define UOS_MOVE (1<<4)
#define START_DMA (1<<0)
#define DMA_GUC_WOPCM_OFFSET _MMIO(0xc340)
+#define GUC_WOPCM_OFFSET_VALID (1<<0)
#define HUC_LOADING_AGENT_VCR (0<<1)
#define HUC_LOADING_AGENT_GUC (1<<1)
#define GUC_WOPCM_OFFSET_SHIFT 14
+#define GUC_WOPCM_OFFSET_MASK (0x3ffff << GUC_WOPCM_OFFSET_SHIFT)
#define GUC_MAX_IDLE_COUNT _MMIO(0xC3E4)
#define HUC_STATUS2 _MMIO(0xD3B0)
#define HUC_FW_VERIFIED (1<<7)
#define GUC_WOPCM_SIZE _MMIO(0xc050)
+#define GUC_WOPCM_SIZE_LOCKED (1<<0)
#define GUC_WOPCM_SIZE_SHIFT 12
#define GUC_WOPCM_SIZE_MASK (0xfffff << GUC_WOPCM_SIZE_SHIFT)
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index 964e49f..58186f2 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -341,11 +341,6 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
guc_disable_communication(guc);
gen9_reset_guc_interrupts(dev_priv);
- /* init WOPCM */
- I915_WRITE(GUC_WOPCM_SIZE, dev_priv->wopcm.guc.size);
- I915_WRITE(DMA_GUC_WOPCM_OFFSET,
- dev_priv->wopcm.guc.base | HUC_LOADING_AGENT_GUC);
-
/* WaEnableuKernelHeaderValidFix:skl */
/* WaEnableGuCBootHashCheckNotSet:skl,bxt,kbl */
if (IS_GEN9(dev_priv))
diff --git a/drivers/gpu/drm/i915/intel_wopcm.c b/drivers/gpu/drm/i915/intel_wopcm.c
index b30d7ff..27c2a63 100644
--- a/drivers/gpu/drm/i915/intel_wopcm.c
+++ b/drivers/gpu/drm/i915/intel_wopcm.c
@@ -219,3 +219,61 @@ int intel_wopcm_init(struct intel_wopcm *wopcm)
return 0;
}
+
+static inline int write_and_verify(struct drm_i915_private *dev_priv,
+ i915_reg_t reg, u32 val, u32 mask,
+ u32 locked_bit)
+{
+ u32 reg_val;
+
+ GEM_BUG_ON(val & ~mask);
+
+ I915_WRITE(reg, val);
+
+ reg_val = I915_READ(reg);
+
+ return (reg_val & mask) != (val | locked_bit) ? -EIO : 0;
+}
+
+/**
+ * intel_wopcm_init_hw() - Setup GuC WOPCM registers.
+ * @wopcm: pointer to intel_wopcm.
+ *
+ * Setup the GuC WOPCM size and offset registers with the stored values. It will
+ * also check the registers locking status to determine whether these registers
+ * are unlocked and can be updated.
+ *
+ * Return: 0 on success. -EIO if registers were locked with incorrect values.
+ */
+int intel_wopcm_init_hw(struct intel_wopcm *wopcm)
+{
+ struct drm_i915_private *dev_priv = wopcm_to_i915(wopcm);
+ u32 huc_agent;
+ u32 mask;
+ int err;
+
+ err = write_and_verify(dev_priv, GUC_WOPCM_SIZE,
+ dev_priv->wopcm.guc.size,
+ GUC_WOPCM_SIZE_MASK | GUC_WOPCM_SIZE_LOCKED,
+ GUC_WOPCM_SIZE_LOCKED);
+ if (err)
+ goto err_out;
+
+ huc_agent = USES_HUC(dev_priv) ? HUC_LOADING_AGENT_GUC : 0;
+ mask = GUC_WOPCM_OFFSET_MASK | GUC_WOPCM_OFFSET_VALID | huc_agent;
+ err = write_and_verify(dev_priv, DMA_GUC_WOPCM_OFFSET,
+ dev_priv->wopcm.guc.base | huc_agent, mask,
+ GUC_WOPCM_OFFSET_VALID);
+ if (err)
+ goto err_out;
+
+ return 0;
+
+err_out:
+ DRM_ERROR("Failed to init WOPCM registers:\n");
+ DRM_ERROR("DMA_GUC_WOPCM_OFFSET=%#x\n",
+ I915_READ(DMA_GUC_WOPCM_OFFSET));
+ DRM_ERROR("GUC_WOPCM_SIZE=%#x\n", I915_READ(GUC_WOPCM_SIZE));
+
+ return err;
+}
diff --git a/drivers/gpu/drm/i915/intel_wopcm.h b/drivers/gpu/drm/i915/intel_wopcm.h
index 39d4847..882f54b 100644
--- a/drivers/gpu/drm/i915/intel_wopcm.h
+++ b/drivers/gpu/drm/i915/intel_wopcm.h
@@ -30,5 +30,6 @@ struct intel_wopcm {
void intel_wopcm_init_early(struct intel_wopcm *wopcm);
int intel_wopcm_init(struct intel_wopcm *wopcm);
+int intel_wopcm_init_hw(struct intel_wopcm *wopcm);
#endif
--
2.7.4
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