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| author | Joerg Roedel <joerg.roedel@amd.com> | 2009-09-03 14:50:20 +0200 |
|---|---|---|
| committer | Joerg Roedel <joerg.roedel@amd.com> | 2009-09-03 15:55:34 +0200 |
| commit | 93f1cc67cf3196174412adca87321b25c1c986b0 (patch) | |
| tree | 205d6e92ca752ea9ddae0ce636c826ec93df8358 /arch | |
| parent | d586d7852ccd0cecb502bf4809f827e60c486af0 (diff) | |
| download | linux-93f1cc67cf3196174412adca87321b25c1c986b0.tar.bz2 | |
x86/amd-iommu: Add reset function for command buffers
This patch factors parts of the command buffer
initialization code into a seperate function which can be
used to reset the command buffer later.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/amd_iommu_types.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/amd_iommu_init.c | 20 |
2 files changed, 18 insertions, 5 deletions
diff --git a/arch/x86/include/asm/amd_iommu_types.h b/arch/x86/include/asm/amd_iommu_types.h index 0c878caaa0a2..c54bc979dc17 100644 --- a/arch/x86/include/asm/amd_iommu_types.h +++ b/arch/x86/include/asm/amd_iommu_types.h @@ -457,4 +457,7 @@ static inline void amd_iommu_stats_init(void) { } #endif /* CONFIG_AMD_IOMMU_STATS */ +/* some function prototypes */ +extern void amd_iommu_reset_cmd_buffer(struct amd_iommu *iommu); + #endif /* _ASM_X86_AMD_IOMMU_TYPES_H */ diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index c1b17e97252e..1752afef948a 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -435,6 +435,20 @@ static u8 * __init alloc_command_buffer(struct amd_iommu *iommu) } /* + * This function resets the command buffer if the IOMMU stopped fetching + * commands from it. + */ +void amd_iommu_reset_cmd_buffer(struct amd_iommu *iommu) +{ + iommu_feature_disable(iommu, CONTROL_CMDBUF_EN); + + writel(0x00, iommu->mmio_base + MMIO_CMD_HEAD_OFFSET); + writel(0x00, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET); + + iommu_feature_enable(iommu, CONTROL_CMDBUF_EN); +} + +/* * This function writes the command buffer address to the hardware and * enables it. */ @@ -450,11 +464,7 @@ static void iommu_enable_command_buffer(struct amd_iommu *iommu) memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET, &entry, sizeof(entry)); - /* set head and tail to zero manually */ - writel(0x00, iommu->mmio_base + MMIO_CMD_HEAD_OFFSET); - writel(0x00, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET); - - iommu_feature_enable(iommu, CONTROL_CMDBUF_EN); + amd_iommu_reset_cmd_buffer(iommu); } static void __init free_command_buffer(struct amd_iommu *iommu) |