[PATCH 1/3] powerpc/64e: convert cmpi to cmpwi in head_64.S
Nicholas Piggin
npiggin at gmail.com
Thu Nov 24 00:02:07 AEDT 2016
>From 80f23935cadb ("powerpc: Convert cmp to cmpd in idle enter sequence"):
PowerPC's "cmp" instruction has four operands. Normally people write
"cmpw" or "cmpd" for the second cmp operand 0 or 1. But, frequently
people forget, and write "cmp" with just three operands.
With older binutils this is silently accepted as if this was "cmpw",
while often "cmpd" is wanted. With newer binutils GAS will complain
about this for 64-bit code. For 32-bit code it still silently assumes
"cmpw" is what is meant.
In this instance the code comes directly from ISA v2.07, including the
cmp, but cmpd is correct. Backport to stable so that new toolchains can
build old kernels.
In this case, cmpwi is called for, so this is just a build fix for
new toolchians.
Stable: v3.0
Cc: Segher Boessenkool <segher at kernel.crashing.org>
Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
arch/powerpc/kernel/head_64.S | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 04c546e..1f7f908 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -214,9 +214,9 @@ booting_thread_hwid:
*/
_GLOBAL(book3e_start_thread)
LOAD_REG_IMMEDIATE(r5, MSR_KERNEL)
- cmpi 0, r3, 0
+ cmpwi r3, 0
beq 10f
- cmpi 0, r3, 1
+ cmpwi r3, 1
beq 11f
/* If the thread id is invalid, just exit. */
b 13f
@@ -241,9 +241,9 @@ _GLOBAL(book3e_start_thread)
* r3 = the thread physical id
*/
_GLOBAL(book3e_stop_thread)
- cmpi 0, r3, 0
+ cmpwi r3, 0
beq 10f
- cmpi 0, r3, 1
+ cmpwi r3, 1
beq 10f
/* If the thread id is invalid, just exit. */
b 13f
--
2.10.2
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