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Commit 549c90dc authored by Chris Wright's avatar Chris Wright Committed by Joerg Roedel
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x86/amd-iommu: warn when issuing command to uninitialized cmd buffer 



To catch future potential issues we can add a warning whenever we issue
a command before the command buffer is fully initialized.

Signed-off-by: default avatarChris Wright <chrisw@sous-sol.org>
Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 75f66533

arch/x86/include/asm/amd_iommu_types.h

+1 −0
Original line number Diff line number Diff line
@@ -141,6 +141,7 @@ 


/* constants to configure the command buffer */

#define CMD_BUFFER_SIZE    8192

#define CMD_BUFFER_UNINITIALIZED 1

#define CMD_BUFFER_ENTRIES 512

#define MMIO_CMD_SIZE_SHIFT 56

#define MMIO_CMD_SIZE_512 (0x9ULL << MMIO_CMD_SIZE_SHIFT)

arch/x86/kernel/amd_iommu.c

+1 −0
Original line number Diff line number Diff line
@@ -392,6 +392,7 @@ static int __iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd) 
	u32 tail, head;

	u8 *target;



	WARN_ON(iommu->cmd_buf_size & CMD_BUFFER_UNINITIALIZED);

	tail = readl(iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);

	target = iommu->cmd_buf + tail;

	memcpy_toio(target, cmd, sizeof(*cmd));

arch/x86/kernel/amd_iommu_init.c

+3 −2
Original line number Diff line number Diff line
@@ -438,7 +438,7 @@ static u8 * __init alloc_command_buffer(struct amd_iommu *iommu) 
	if (cmd_buf == NULL)

		return NULL;



	iommu->cmd_buf_size = CMD_BUFFER_SIZE;

	iommu->cmd_buf_size = CMD_BUFFER_SIZE | CMD_BUFFER_UNINITIALIZED;



	return cmd_buf;

}
@@ -474,12 +474,13 @@ static void iommu_enable_command_buffer(struct amd_iommu *iommu) 
		    &entry, sizeof(entry));



	amd_iommu_reset_cmd_buffer(iommu);

	iommu->cmd_buf_size &= ~(CMD_BUFFER_UNINITIALIZED);

}



static void __init free_command_buffer(struct amd_iommu *iommu)

{

	free_pages((unsigned long)iommu->cmd_buf,

		   get_order(iommu->cmd_buf_size));

		   get_order(iommu->cmd_buf_size & ~(CMD_BUFFER_UNINITIALIZED)));

}



/* allocates the memory where the IOMMU will log its events to */