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/ci_smc.c b/drivers/gpu/drm/radeon/ci_smc.c
index 53b43dd..252e10a 100644
--- a/drivers/gpu/drm/radeon/ci_smc.c
+++ b/drivers/gpu/drm/radeon/ci_smc.c
@@ -47,10 +47,11 @@
u32 smc_start_address,
const u8 *src, u32 byte_count, u32 limit)
{
+ unsigned long flags;
u32 data, original_data;
u32 addr;
u32 extra_shift;
- int ret;
+ int ret = 0;
if (smc_start_address & 3)
return -EINVAL;
@@ -59,13 +60,14 @@
addr = smc_start_address;
+ spin_lock_irqsave(&rdev->smc_idx_lock, flags);
while (byte_count >= 4) {
/* SMC address space is BE */
data = (src[0] << 24) | (src[1] << 16) | (src[2] << 8) | src[3];
ret = ci_set_smc_sram_address(rdev, addr, limit);
if (ret)
- return ret;
+ goto done;
WREG32(SMC_IND_DATA_0, data);
@@ -80,7 +82,7 @@
ret = ci_set_smc_sram_address(rdev, addr, limit);
if (ret)
- return ret;
+ goto done;
original_data = RREG32(SMC_IND_DATA_0);
@@ -97,11 +99,15 @@
ret = ci_set_smc_sram_address(rdev, addr, limit);
if (ret)
- return ret;
+ goto done;
WREG32(SMC_IND_DATA_0, data);
}
- return 0;
+
+done:
+ spin_unlock_irqrestore(&rdev->smc_idx_lock, flags);
+
+ return ret;
}
void ci_start_smc(struct radeon_device *rdev)
@@ -197,6 +203,7 @@
int ci_load_smc_ucode(struct radeon_device *rdev, u32 limit)
{
+ unsigned long flags;
u32 ucode_start_address;
u32 ucode_size;
const u8 *src;
@@ -219,6 +226,7 @@
return -EINVAL;
src = (const u8 *)rdev->smc_fw->data;
+ spin_lock_irqsave(&rdev->smc_idx_lock, flags);
WREG32(SMC_IND_INDEX_0, ucode_start_address);
WREG32_P(SMC_IND_ACCESS_CNTL, AUTO_INCREMENT_IND_0, ~AUTO_INCREMENT_IND_0);
while (ucode_size >= 4) {
@@ -231,6 +239,7 @@
ucode_size -= 4;
}
WREG32_P(SMC_IND_ACCESS_CNTL, 0, ~AUTO_INCREMENT_IND_0);
+ spin_unlock_irqrestore(&rdev->smc_idx_lock, flags);
return 0;
}
@@ -238,25 +247,29 @@
int ci_read_smc_sram_dword(struct radeon_device *rdev,
u32 smc_address, u32 *value, u32 limit)
{
+ unsigned long flags;
int ret;
+ spin_lock_irqsave(&rdev->smc_idx_lock, flags);
ret = ci_set_smc_sram_address(rdev, smc_address, limit);
- if (ret)
- return ret;
+ if (ret == 0)
+ *value = RREG32(SMC_IND_DATA_0);
+ spin_unlock_irqrestore(&rdev->smc_idx_lock, flags);
- *value = RREG32(SMC_IND_DATA_0);
- return 0;
+ return ret;
}
int ci_write_smc_sram_dword(struct radeon_device *rdev,
u32 smc_address, u32 value, u32 limit)
{
+ unsigned long flags;
int ret;
+ spin_lock_irqsave(&rdev->smc_idx_lock, flags);
ret = ci_set_smc_sram_address(rdev, smc_address, limit);
- if (ret)
- return ret;
+ if (ret == 0)
+ WREG32(SMC_IND_DATA_0, value);
+ spin_unlock_irqrestore(&rdev->smc_idx_lock, flags);
- WREG32(SMC_IND_DATA_0, value);
- return 0;
+ return ret;
}