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authorJoerg Roedel <joerg.roedel@amd.com>2008-12-03 12:19:27 +0100
committerJoerg Roedel <joerg.roedel@amd.com>2008-12-03 12:20:46 +0100
commit09ee17eb8ea89514c13980c4010bdbbaea8630c2 (patch)
tree2ca56f35c476ded55324b5bc11f050c7131980dd
parentf91ba190648be4ff127d6aaf3993ac19d66dc2c2 (diff)
AMD IOMMU: fix possible race while accessing iommu->need_sync
The access to the iommu->need_sync member needs to be protected by the iommu->lock. Otherwise this is a possible race condition. Fix it with this patch. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
-rw-r--r--arch/x86/kernel/amd_iommu.c33
1 files changed, 13 insertions, 20 deletions
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index a232e5a85d4..5662e226b0c 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -187,6 +187,8 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
spin_lock_irqsave(&iommu->lock, flags);
ret = __iommu_queue_command(iommu, cmd);
+ if (!ret)
+ iommu->need_sync = 1;
spin_unlock_irqrestore(&iommu->lock, flags);
return ret;
@@ -210,10 +212,13 @@ static int iommu_completion_wait(struct amd_iommu *iommu)
cmd.data[0] = CMD_COMPL_WAIT_INT_MASK;
CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT);
- iommu->need_sync = 0;
-
spin_lock_irqsave(&iommu->lock, flags);
+ if (!iommu->need_sync)
+ goto out;
+
+ iommu->need_sync = 0;
+
ret = __iommu_queue_command(iommu, &cmd);
if (ret)
@@ -254,8 +259,6 @@ static int iommu_queue_inv_dev_entry(struct amd_iommu *iommu, u16 devid)
ret = iommu_queue_command(iommu, &cmd);
- iommu->need_sync = 1;
-
return ret;
}
@@ -281,8 +284,6 @@ static int iommu_queue_inv_iommu_pages(struct amd_iommu *iommu,
ret = iommu_queue_command(iommu, &cmd);
- iommu->need_sync = 1;
-
return ret;
}
@@ -762,8 +763,6 @@ static void set_device_domain(struct amd_iommu *iommu,
write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
iommu_queue_inv_dev_entry(iommu, devid);
-
- iommu->need_sync = 1;
}
/*****************************************************************************
@@ -1034,8 +1033,7 @@ static dma_addr_t map_single(struct device *dev, phys_addr_t paddr,
if (addr == bad_dma_address)
goto out;
- if (unlikely(iommu->need_sync))
- iommu_completion_wait(iommu);
+ iommu_completion_wait(iommu);
out:
spin_unlock_irqrestore(&domain->lock, flags);
@@ -1063,8 +1061,7 @@ static void unmap_single(struct device *dev, dma_addr_t dma_addr,
__unmap_single(iommu, domain->priv, dma_addr, size, dir);
- if (unlikely(iommu->need_sync))
- iommu_completion_wait(iommu);
+ iommu_completion_wait(iommu);
spin_unlock_irqrestore(&domain->lock, flags);
}
@@ -1130,8 +1127,7 @@ static int map_sg(struct device *dev, struct scatterlist *sglist,
goto unmap;
}
- if (unlikely(iommu->need_sync))
- iommu_completion_wait(iommu);
+ iommu_completion_wait(iommu);
out:
spin_unlock_irqrestore(&domain->lock, flags);
@@ -1176,8 +1172,7 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist,
s->dma_address = s->dma_length = 0;
}
- if (unlikely(iommu->need_sync))
- iommu_completion_wait(iommu);
+ iommu_completion_wait(iommu);
spin_unlock_irqrestore(&domain->lock, flags);
}
@@ -1228,8 +1223,7 @@ static void *alloc_coherent(struct device *dev, size_t size,
goto out;
}
- if (unlikely(iommu->need_sync))
- iommu_completion_wait(iommu);
+ iommu_completion_wait(iommu);
out:
spin_unlock_irqrestore(&domain->lock, flags);
@@ -1260,8 +1254,7 @@ static void free_coherent(struct device *dev, size_t size,
__unmap_single(iommu, domain->priv, dma_addr, size, DMA_BIDIRECTIONAL);
- if (unlikely(iommu->need_sync))
- iommu_completion_wait(iommu);
+ iommu_completion_wait(iommu);
spin_unlock_irqrestore(&domain->lock, flags);