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Commit 93f1cc67 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

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: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent d586d785

arch/x86/include/asm/amd_iommu_types.h

+3 −0
Original line number Diff line number Diff line
@@ -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 */

arch/x86/kernel/amd_iommu_init.c

+15 −5
Original line number Diff line number Diff line
@@ -434,6 +434,20 @@ static u8 * __init alloc_command_buffer(struct amd_iommu *iommu) 
	return cmd_buf;

}



/*

 * 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)