Messages in this thread | | | Date | Mon, 14 Nov 2022 09:18:48 +0530 | Subject | Re: [PATCH v5 02/16] powerpc: Override __ALIGN and __ALIGN_STR macros | From | Sathvika Vasireddy <> |
| |
Hi Peter,
On 03/11/22 14:18, Peter Zijlstra wrote: > On Wed, Nov 02, 2022 at 12:35:07PM +0000, Christophe Leroy wrote: >> >> Le 28/10/2022 à 16:33, Sathvika Vasireddy a écrit : >>> In a subsequent patch, we would want to annotate powerpc assembly functions >>> with SYM_FUNC_START_LOCAL macro. This macro depends on __ALIGN macro. >>> >>> The default expansion of __ALIGN macro is: >>> #define __ALIGN .align 4,0x90 >>> >>> So, override __ALIGN and __ALIGN_STR macros to use the same alignment as >>> that of the existing _GLOBAL macro. Also, do not pad with 0x90, because >>> repeated 0x90s are not a nop or trap on powerpc. >> By the way, do we know what the instruction 0x90909090 is on powerpc ? >> Is that something valid or not ? > Please also look at the version that's in tip/x86/core (and next). This > stuff should be gone now. > > include/linux/linkage.h now reads like: > > #ifndef __ALIGN > #define __ALIGN .balign CONFIG_FUNCTION_ALIGNMENT > #define __ALIGN_STR __stringify(__ALIGN) > #endif
Since the above mentioned changes are not a part of powerpc/merge branch yet, I am retaining this patch for this merge cycle and will post a cleanup patch (to move to using FUNCTION_ALIGNMENT_4B) after the next -rc1.
Thanks, Sathvika
| |