| Message ID | 20161123130209.1667-2-npiggin@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Wed, 2016-11-23 at 13:02:07 UTC, Nicholas Piggin wrote: > >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@kernel.crashing.org> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/f87f253bac3ce4a4eb2a60a1ae604d cheers
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
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@kernel.crashing.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/kernel/head_64.S | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)