drm/radeon: protect concurrent smc register access with a spinlock
smc registers are access indirectly via the main mmio aperture, so
there may be problems with concurrent access. This adds a spinlock
to protect access to this register space.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index ff8b564..6d6d099 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -2110,6 +2110,8 @@
resource_size_t rmmio_size;
/* protects concurrent MM_INDEX/DATA based register access */
spinlock_t mmio_idx_lock;
+ /* protects concurrent SMC based register access */
+ spinlock_t smc_idx_lock;
void __iomem *rmmio;
radeon_rreg_t mc_rreg;
radeon_wreg_t mc_wreg;
@@ -2292,17 +2294,24 @@
static inline u32 tn_smc_rreg(struct radeon_device *rdev, u32 reg)
{
+ unsigned long flags;
u32 r;
+ spin_lock_irqsave(&rdev->smc_idx_lock, flags);
WREG32(TN_SMC_IND_INDEX_0, (reg));
r = RREG32(TN_SMC_IND_DATA_0);
+ spin_unlock_irqrestore(&rdev->smc_idx_lock, flags);
return r;
}
static inline void tn_smc_wreg(struct radeon_device *rdev, u32 reg, u32 v)
{
+ unsigned long flags;
+
+ spin_lock_irqsave(&rdev->smc_idx_lock, flags);
WREG32(TN_SMC_IND_INDEX_0, (reg));
WREG32(TN_SMC_IND_DATA_0, (v));
+ spin_unlock_irqrestore(&rdev->smc_idx_lock, flags);
}
static inline u32 r600_rcu_rreg(struct radeon_device *rdev, u32 reg)