[PATCH] xen/arm64: head: document missing input registers for MMU functions

[Mykola Kvach <xakep.amatop@xxxxxxxxx>]

From: Mykola Kvach <mykola_kvach@xxxxxxxx>

Add missing input register descriptions to enable_secondary_cpu_mm
and enable_boot_cpu_mm functions.

Specifically:
- x19 is used in enable_boot_cpu_mm as physical start address.
- x20 is used in both functions for physical offset passed to load_paddr.

This update improves code clarity and consistency in comments.

No functional changes are introduced by this patch.

Signed-off-by: Mykola Kvach <mykola_kvach@xxxxxxxx>
---
 xen/arch/arm/arm64/mmu/head.S | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/xen/arch/arm/arm64/mmu/head.S b/xen/arch/arm/arm64/mmu/head.S
index 634156f83d..033b3a018a 100644
--- a/xen/arch/arm/arm64/mmu/head.S
+++ b/xen/arch/arm/arm64/mmu/head.S
@@ -313,6 +313,7 @@ END(enable_mmu)
  *
  * Inputs:
  *   lr : Virtual address to return to.
+ *   x20: phys offset (used by load_paddr)
  *
  * Clobbers x0 - x6
  */
@@ -337,6 +338,8 @@ END(enable_secondary_cpu_mm)
  *
  * Inputs:
  *   lr : Virtual address to return to.
+ *   x19: paddr(start) (used by remove_identity_mapping)
+ *   x20: phys offset (used by load_paddr)
  *
  * Clobbers x0 - x6
  */
-- 
2.48.1