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: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index b06f29e..71dfc0a 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -392,6 +392,7 @@
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));
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 8975965..5edf41c 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -438,7 +438,7 @@
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 @@
&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 */