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: Joerg 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: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index ffb8ac8..c2be3ad 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -278,3 +278,33 @@
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));
+}
+