[PATCH v13 5/6] drm/i915/guc: Check the locking status of GuC WOPCM registers
Jackie Li
yaodong.li at intel.com
Tue Mar 13 18:01:49 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_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 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)
v12:
- Updated function kernel-doc to align with code changes (Michal)
- Updated code to use wopcm pointer directly (Michal)
v13:
- Updated the order of s-o-b/cc/r-b tags (Sagar)
BSpec: 10875, 10833
Signed-off-by: Jackie Li <yaodong.li at intel.com>
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>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko at intel.com> (v11)
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com> (v12)
---
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 | 64 ++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_wopcm.h | 1 +
5 files changed, 74 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index b58402b..e19aa8b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5147,6 +5147,12 @@ 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 ed5a6fc..6316548 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -367,11 +367,6 @@ int intel_uc_init_hw(struct drm_i915_private *dev_priv)
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 f14a56f..222e2af 100644
--- a/drivers/gpu/drm/i915/intel_wopcm.c
+++ b/drivers/gpu/drm/i915/intel_wopcm.c
@@ -207,3 +207,67 @@ 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 calculated values. It
+ * will verify the register values to make sure the registers are locked with
+ * correct values.
+ *
+ * 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;
+
+ if (!USES_GUC(dev_priv))
+ return 0;
+
+ GEM_BUG_ON(!HAS_GUC(dev_priv));
+ GEM_BUG_ON(!wopcm->guc.size);
+ GEM_BUG_ON(!wopcm->guc.base);
+
+ err = write_and_verify(dev_priv, GUC_WOPCM_SIZE, 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,
+ 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 93c402c..6298910 100644
--- a/drivers/gpu/drm/i915/intel_wopcm.h
+++ b/drivers/gpu/drm/i915/intel_wopcm.h
@@ -26,5 +26,6 @@ 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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