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AMD IOMMU: refactor completion wait handling into separate functions

Browse source 
Impact: split one function into three

The separate functions are required synchronize commands across all
hardware IOMMUs in the system.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
This commit is contained in:
Joerg Roedel 2008-12-02 20:34:41 +01:00
parent a2acfb7579
commit 8d201968e1
1 changed files with 47 additions and 25 deletions
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72
arch/x86/kernel/amd_iommu.c
View file

@ -196,34 +196,14 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
}
/*
* This function is called whenever we need to ensure that the IOMMU has
* completed execution of all commands we sent. It sends a
* COMPLETION_WAIT command and waits for it to finish. The IOMMU informs
* us about that by writing a value to a physical address we pass with
* the command.
* This function waits until an IOMMU has completed a completion
* wait command
*/
static int iommu_completion_wait(struct amd_iommu *iommu)
static void __iommu_wait_for_completion(struct amd_iommu *iommu)
{
int ret = 0, ready = 0;
int ready = 0;
unsigned status = 0;
struct iommu_cmd cmd;
unsigned long flags, i = 0;
memset(&cmd, 0, sizeof(cmd));
cmd.data[0] = CMD_COMPL_WAIT_INT_MASK;
CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT);
spin_lock_irqsave(&iommu->lock, flags);
if (!iommu->need_sync)
goto out;
iommu->need_sync = 0;
ret = __iommu_queue_command(iommu, &cmd);
if (ret)
goto out;
unsigned long i = 0;
while (!ready && (i < EXIT_LOOP_COUNT)) {
++i;
@ -238,6 +218,48 @@ static int iommu_completion_wait(struct amd_iommu *iommu)
if (unlikely(i == EXIT_LOOP_COUNT))
panic("AMD IOMMU: Completion wait loop failed\n");
}
/*
* This function queues a completion wait command into the command
* buffer of an IOMMU
*/
static int __iommu_completion_wait(struct amd_iommu *iommu)
{
struct iommu_cmd cmd;
memset(&cmd, 0, sizeof(cmd));
cmd.data[0] = CMD_COMPL_WAIT_INT_MASK;
CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT);
return __iommu_queue_command(iommu, &cmd);
}
/*
* This function is called whenever we need to ensure that the IOMMU has
* completed execution of all commands we sent. It sends a
* COMPLETION_WAIT command and waits for it to finish. The IOMMU informs
* us about that by writing a value to a physical address we pass with
* the command.
*/
static int iommu_completion_wait(struct amd_iommu *iommu)
{
int ret = 0;
unsigned long flags;
spin_lock_irqsave(&iommu->lock, flags);
if (!iommu->need_sync)
goto out;
ret = __iommu_completion_wait(iommu);
iommu->need_sync = 0;
if (ret)
goto out;
__iommu_wait_for_completion(iommu);
out:
spin_unlock_irqrestore(&iommu->lock, flags);