[Xen-devel,v3,17/28] xen/arm32: head: Document enable_mmu()

Message ID 20190812173019.11956-18-julien.grall@arm.com
State New
Headers show
Series
  • xen/arm: Rework head.S to make it more compliant with the Arm Arm
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Commit Message

Julien Grall Aug. 12, 2019, 5:30 p.m.
Document the behavior and the main registers usage within enable_mmu().

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes in v3:
        - Add Stefano's acked-by

    Changes in v2:
        - Patch added
---
 xen/arch/arm/arm32/head.S | 7 +++++++
 1 file changed, 7 insertions(+)

Patch

diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
index 83f8774e2a..f8603051e4 100644
--- a/xen/arch/arm/arm32/head.S
+++ b/xen/arch/arm/arm32/head.S
@@ -423,6 +423,13 @@  virtphys_clash:
         b     fail
 ENDPROC(create_page_tables)
 
+/*
+ * Turn on the Data Cache and the MMU. The function will return on the 1:1
+ * mapping. In other word, the caller is responsible to switch to the runtime
+ * mapping.
+ *
+ * Clobbers r0 - r3
+ */
 enable_mmu:
         PRINT("- Turning on paging -\r\n")