[PATCH 5/6] drm/i915/guc: Check the locking status of GuC WOPCM registers
Jackie Li
yaodong.li at intel.com
Sat Feb 3 04:00:37 UTC 2018
GuC WOPCM registers are write-once registers. Current driver code
accesses these registers without checking the accessibility to these
registers, this will lead unpredictable driver behaviors if these
registers were touch by other components (such as faulty BIOS code).
This patch moves the GuC WOPCM register updating operations into
intel_guc_wopcm.c and adds checks before and after the write to GuC
WOPCM registers to 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:
- Add space to register lock bit macro definition (Sagar)
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/intel_guc.h | 2 +-
drivers/gpu/drm/i915/intel_guc_reg.h | 2 +
drivers/gpu/drm/i915/intel_guc_wopcm.c | 92 ++++++++++++++++++++++++++++++++--
drivers/gpu/drm/i915/intel_guc_wopcm.h | 9 +++-
drivers/gpu/drm/i915/intel_uc.c | 5 +-
5 files changed, 100 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
index 06f315e..cb1703b 100644
--- a/drivers/gpu/drm/i915/intel_guc.h
+++ b/drivers/gpu/drm/i915/intel_guc.h
@@ -122,7 +122,7 @@ static inline u32 intel_guc_ggtt_offset(struct intel_guc *guc,
{
u32 offset = i915_ggtt_offset(vma);
- GEM_BUG_ON(!guc->wopcm.valid);
+ GEM_BUG_ON(!(guc->wopcm.flags & INTEL_GUC_WOPCM_VALID));
GEM_BUG_ON(offset < guc->wopcm.top);
GEM_BUG_ON(range_overflows_t(u64, offset, vma->size, GUC_GGTT_TOP));
diff --git a/drivers/gpu/drm/i915/intel_guc_reg.h b/drivers/gpu/drm/i915/intel_guc_reg.h
index de4f78b..18cb2ef 100644
--- a/drivers/gpu/drm/i915/intel_guc_reg.h
+++ b/drivers/gpu/drm/i915/intel_guc_reg.h
@@ -66,6 +66,7 @@
#define UOS_MOVE (1<<4)
#define START_DMA (1<<0)
#define DMA_GUC_WOPCM_OFFSET _MMIO(0xc340)
+#define DMA_GUC_WOPCM_OFFSET_MASK (0xffffc000)
#define HUC_LOADING_AGENT_VCR (0<<1)
#define HUC_LOADING_AGENT_GUC (1<<1)
#define GUC_MAX_IDLE_COUNT _MMIO(0xC3E4)
@@ -75,6 +76,7 @@
/* Defines WOPCM space available to GuC firmware */
#define GUC_WOPCM_SIZE _MMIO(0xc050)
+#define GUC_WOPCM_REG_LOCKED BIT(0)
#define GEN8_GT_PM_CONFIG _MMIO(0x138140)
#define GEN9LP_GT_PM_CONFIG _MMIO(0x138140)
diff --git a/drivers/gpu/drm/i915/intel_guc_wopcm.c b/drivers/gpu/drm/i915/intel_guc_wopcm.c
index 3cba9ac..bb99ad8 100644
--- a/drivers/gpu/drm/i915/intel_guc_wopcm.c
+++ b/drivers/gpu/drm/i915/intel_guc_wopcm.c
@@ -89,6 +89,54 @@ static inline int guc_wopcm_check_hw_restrictions(struct intel_guc *guc)
return 0;
}
+static inline bool __reg_locked(struct drm_i915_private *dev_priv,
+ i915_reg_t reg)
+{
+ return !!(I915_READ(reg) & GUC_WOPCM_REG_LOCKED);
+}
+
+static inline bool guc_wopcm_locked(struct intel_guc *guc)
+{
+ struct drm_i915_private *i915 = guc_to_i915(guc);
+ bool size_reg_locked = __reg_locked(i915, GUC_WOPCM_SIZE);
+ bool offset_reg_locked = __reg_locked(i915, DMA_GUC_WOPCM_OFFSET);
+
+ return size_reg_locked && offset_reg_locked;
+}
+
+static inline void guc_wopcm_hw_update(struct intel_guc *guc)
+{
+ struct drm_i915_private *dev_priv = guc_to_i915(guc);
+
+ /* GuC WOPCM registers should be unlocked at this point. */
+ GEM_BUG_ON(__reg_locked(dev_priv, GUC_WOPCM_SIZE));
+ GEM_BUG_ON(__reg_locked(dev_priv, DMA_GUC_WOPCM_OFFSET));
+
+ I915_WRITE(GUC_WOPCM_SIZE, guc->wopcm.size);
+ I915_WRITE(DMA_GUC_WOPCM_OFFSET,
+ guc->wopcm.offset | HUC_LOADING_AGENT_GUC);
+
+ GEM_BUG_ON(!__reg_locked(dev_priv, GUC_WOPCM_SIZE));
+ GEM_BUG_ON(!__reg_locked(dev_priv, DMA_GUC_WOPCM_OFFSET));
+}
+
+static inline bool guc_wopcm_regs_valid(struct intel_guc *guc)
+{
+ struct drm_i915_private *dev_priv = guc_to_i915(guc);
+ u32 size, offset;
+ bool guc_loads_huc;
+
+ /* GuC WOPCM size should be always multiple of 4K pages. */
+ size = I915_READ(GUC_WOPCM_SIZE) & PAGE_MASK;
+ offset = I915_READ(DMA_GUC_WOPCM_OFFSET);
+
+ guc_loads_huc = !!(offset & HUC_LOADING_AGENT_GUC);
+ offset &= DMA_GUC_WOPCM_OFFSET_MASK;
+
+ return guc_loads_huc && (size == guc->wopcm.size) &&
+ (offset == guc->wopcm.offset);
+}
+
/**
* intel_guc_wopcm_init() - Initialize the GuC WOPCM..
* @guc: intel guc.
@@ -111,8 +159,7 @@ int intel_guc_wopcm_init(struct intel_guc *guc, u32 guc_fw_size,
u32 offset, size, top;
int err;
- if (guc->wopcm.valid)
- return 0;
+ GEM_BUG_ON(guc->wopcm.flags & INTEL_GUC_WOPCM_VALID);
if (!guc_fw_size)
return -EINVAL;
@@ -153,10 +200,49 @@ int intel_guc_wopcm_init(struct intel_guc *guc, u32 guc_fw_size,
if (err)
return err;
- guc->wopcm.valid = 1;
+ guc->wopcm.flags |= INTEL_GUC_WOPCM_VALID;
DRM_DEBUG_DRIVER("GuC WOPCM offset %dKB, size %dKB, top %dKB\n",
offset >> 10, size >> 10, top >> 10);
return 0;
}
+
+/**
+ * intel_guc_wopcm_init_hw() - Setup GuC WOPCM registers.
+ * @guc: intel guc.
+ *
+ * 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.
+ */
+void intel_guc_wopcm_init_hw(struct intel_guc *guc)
+{
+ bool locked = guc_wopcm_locked(guc);
+
+ GEM_BUG_ON(!(guc->wopcm.flags & INTEL_GUC_WOPCM_VALID));
+
+ /*
+ * Bug if driver hasn't updated the HW Registers and GuC WOPCM has been
+ * locked. Return directly if WOPCM was locked and we have updated
+ * the registers.
+ */
+ if (locked) {
+ /*
+ * Mark as updated if registers contained correct values.
+ * This will happen while reloading the driver module without
+ * rebooting the system.
+ */
+ if (guc_wopcm_regs_valid(guc))
+ goto out;
+
+ GEM_BUG_ON(!(guc->wopcm.flags & INTEL_GUC_WOPCM_HW_UPDATED));
+ return;
+ }
+
+ /* Always update registers when GuC WOPCM is not locked. */
+ guc_wopcm_hw_update(guc);
+
+out:
+ guc->wopcm.flags |= INTEL_GUC_WOPCM_HW_UPDATED;
+}
diff --git a/drivers/gpu/drm/i915/intel_guc_wopcm.h b/drivers/gpu/drm/i915/intel_guc_wopcm.h
index eca65f4..a8d55a7 100644
--- a/drivers/gpu/drm/i915/intel_guc_wopcm.h
+++ b/drivers/gpu/drm/i915/intel_guc_wopcm.h
@@ -49,12 +49,16 @@ struct intel_guc;
/* GuC WOPCM starts at 144KB above GuC WOPCM offset on BXT */
#define GEN9_GUC_WOPCM_OFFSET (0x24000)
+/* GuC WOPCM flags*/
+#define INTEL_GUC_WOPCM_VALID BIT(0)
+#define INTEL_GUC_WOPCM_HW_UPDATED BIT(1)
+
/**
* intel_guc_wopcm - GuC WOPCM related settings.
* @offset: GuC WOPCM offset from the WOPCM base.
* @size: size of GuC WOPCM for GuC firmware.
* @top: start of the non-GuC WOPCM memory.
- * @valid: whether this structure contains valid info.
+ * @flags: bitmap of INTEL_GUC_WOPCM_<foo>.
*
* We simply use this structure to track the GuC use of WOPCM. The layout of
* WOPCM would be defined by writing to GuC WOPCM offset and size registers as
@@ -72,7 +76,7 @@ struct intel_guc_wopcm {
u32 offset;
u32 size;
u32 top;
- u32 valid;
+ u32 flags;
};
/**
@@ -90,5 +94,6 @@ static inline void intel_guc_wopcm_init_early(struct intel_guc_wopcm *wopcm)
}
int intel_guc_wopcm_init(struct intel_guc *guc, u32 guc_size, u32 huc_size);
+void intel_guc_wopcm_init_hw(struct intel_guc *guc);
#endif
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index 2292f31..62e85b5 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -346,10 +346,7 @@ 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, guc->wopcm.size);
- I915_WRITE(DMA_GUC_WOPCM_OFFSET,
- guc->wopcm.offset | HUC_LOADING_AGENT_GUC);
+ intel_guc_wopcm_init_hw(guc);
/* WaEnableuKernelHeaderValidFix:skl */
/* WaEnableGuCBootHashCheckNotSet:skl,bxt,kbl */
--
2.7.4
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