x0 will contain the only argument to arm64_relocate_new_kernel; don't
use it as a temp. Reassigned registers to free-up x0.
Signed-off-by: Pavel Tatashin <[email protected]>
---
arch/arm64/kernel/relocate_kernel.S | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/kernel/relocate_kernel.S b/arch/arm64/kernel/relocate_kernel.S
index e9c974ea4717..41f9c95fabe8 100644
--- a/arch/arm64/kernel/relocate_kernel.S
+++ b/arch/arm64/kernel/relocate_kernel.S
@@ -32,14 +32,14 @@ ENTRY(arm64_relocate_new_kernel)
mov x14, xzr /* x14 = entry ptr */
mov x13, xzr /* x13 = copy dest */
/* Clear the sctlr_el2 flags. */
- mrs x0, CurrentEL
- cmp x0, #CurrentEL_EL2
+ mrs x2, CurrentEL
+ cmp x2, #CurrentEL_EL2
b.ne 1f
- mrs x0, sctlr_el2
+ mrs x2, sctlr_el2
ldr x1, =SCTLR_ELx_FLAGS
- bic x0, x0, x1
+ bic x2, x2, x1
pre_disable_mmu_workaround
- msr sctlr_el2, x0
+ msr sctlr_el2, x2
isb
1: /* Check if the new image needs relocation. */
tbnz x16, IND_DONE_BIT, .Ldone
@@ -51,17 +51,17 @@ ENTRY(arm64_relocate_new_kernel)
tbz x16, IND_SOURCE_BIT, .Ltest_indirection
/* Invalidate dest page to PoC. */
- mov x0, x13
- add x20, x0, #PAGE_SIZE
+ mov x2, x13
+ add x20, x2, #PAGE_SIZE
sub x1, x15, #1
- bic x0, x0, x1
-2: dc ivac, x0
- add x0, x0, x15
- cmp x0, x20
+ bic x2, x2, x1
+2: dc ivac, x2
+ add x2, x2, x15
+ cmp x2, x20
b.lo 2b
dsb sy
- copy_page x13, x12, x0, x1, x2, x3, x4, x5, x6, x7
+ copy_page x13, x12, x1, x2, x3, x4, x5, x6, x7, x8
b .Lnext
.Ltest_indirection:
tbz x16, IND_INDIRECTION_BIT, .Ltest_destination
--
2.17.1
Hi Pavel,
On 26/03/2020 03:24, Pavel Tatashin wrote:
> x0 will contain the only argument to arm64_relocate_new_kernel; don't
> use it as a temp. Reassigned registers to free-up x0.
The missing bit of motivation is _why_ you need x0 keep its value until the end of this code.
With that covered,
Reviewed-by: James Morse <[email protected]>
Thanks,
James