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Commit b36ca91e authored by Joerg Roedel's avatar Joerg Roedel Committed by Ingo Molnar
Browse files

x86, AMD IOMMU: add command buffer (de-)allocation 



This patch adds the functions to allocate and deallocate the command buffer for
one IOMMU in the system.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
Cc: bhavna.sarathy@amd.com
Cc: Sebastian.Biemueller@amd.com
Cc: robert.richter@amd.com
Cc: joro@8bytes.org
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent b2026aa2

arch/x86/kernel/amd_iommu_init.c

+30 −0
Original line number Diff line number Diff line
@@ -278,3 +278,33 @@ static int __init find_last_devid_acpi(struct acpi_table_header *table) 
	return 0;

}



static u8 * __init alloc_command_buffer(struct amd_iommu *iommu)

{

	u8 *cmd_buf = (u8 *)__get_free_pages(GFP_KERNEL,

			get_order(CMD_BUFFER_SIZE));

	u64 entry = 0;



	if (cmd_buf == NULL)

		return NULL;



	iommu->cmd_buf_size = CMD_BUFFER_SIZE;



	memset(cmd_buf, 0, CMD_BUFFER_SIZE);



	entry = (u64)virt_to_phys(cmd_buf);

	entry |= MMIO_CMD_SIZE_512;

	memcpy_toio(iommu->mmio_base + MMIO_CMD_BUF_OFFSET,

			&entry, sizeof(entry));



	iommu_feature_enable(iommu, CONTROL_CMDBUF_EN);



	return cmd_buf;

}



static void __init free_command_buffer(struct amd_iommu *iommu)

{

	if (iommu->cmd_buf)

		free_pages((unsigned long)iommu->cmd_buf,

				get_order(CMD_BUFFER_SIZE));

}