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authorJoerg Roedel <joerg.roedel@amd.com>2008-12-02 20:34:41 +0100
committerJoerg Roedel <joerg.roedel@amd.com>2009-01-03 14:11:54 +0100
commit8d201968e15f56ae2837b0d0b64d3fff098857b0 (patch)
treec2f57f4c599e8f401b3ddc2614840014be4a34e4 /arch
parenta2acfb75792511a35586db80a38b8e4701a97730 (diff)
AMD IOMMU: refactor completion wait handling into separate functions
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/amd_iommu.c68
1 files changed, 45 insertions, 23 deletions
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 0922d5fe633..2280ef86651 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -196,6 +196,46 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
}
/*
+ * This function waits until an IOMMU has completed a completion
+ * wait command
+ */
+static void __iommu_wait_for_completion(struct amd_iommu *iommu)
+{
+ int ready = 0;
+ unsigned status = 0;
+ unsigned long i = 0;
+
+ while (!ready && (i < EXIT_LOOP_COUNT)) {
+ ++i;
+ /* wait for the bit to become one */
+ status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET);
+ ready = status & MMIO_STATUS_COM_WAIT_INT_MASK;
+ }
+
+ /* set bit back to zero */
+ status &= ~MMIO_STATUS_COM_WAIT_INT_MASK;
+ writel(status, iommu->mmio_base + MMIO_STATUS_OFFSET);
+
+ 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
@@ -204,40 +244,22 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
*/
static int iommu_completion_wait(struct amd_iommu *iommu)
{
- int ret = 0, 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);
+ int ret = 0;
+ unsigned long flags;
spin_lock_irqsave(&iommu->lock, flags);
if (!iommu->need_sync)
goto out;
- iommu->need_sync = 0;
+ ret = __iommu_completion_wait(iommu);
- ret = __iommu_queue_command(iommu, &cmd);
+ iommu->need_sync = 0;
if (ret)
goto out;
- while (!ready && (i < EXIT_LOOP_COUNT)) {
- ++i;
- /* wait for the bit to become one */
- status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET);
- ready = status & MMIO_STATUS_COM_WAIT_INT_MASK;
- }
-
- /* set bit back to zero */
- status &= ~MMIO_STATUS_COM_WAIT_INT_MASK;
- writel(status, iommu->mmio_base + MMIO_STATUS_OFFSET);
-
- if (unlikely(i == EXIT_LOOP_COUNT))
- panic("AMD IOMMU: Completion wait loop failed\n");
+ __iommu_wait_for_completion(iommu);
out:
spin_unlock_irqrestore(&iommu->lock, flags);