diff options
| author | Jeroen Hofstee <jeroen@myspectrum.nl> | 2014-07-30 21:54:52 +0200 |
|---|---|---|
| committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2014-09-09 13:51:08 +0200 |
| commit | c65a2abb6c0a9ab1c70f5241716066c9480ce96a (patch) | |
| tree | c675b1eb38c962cc2007de8c9d7cbfc4cdcbb27a /arch | |
| parent | 1401d87b444bf114528e997db552d22142918d33 (diff) | |
ARM: make gd a function for clang
"clang does not support global register variables; this is
unlikely to be implemented soon because it requires additional
LLVM backend support" [1]
Workaround it by obtaining the value of gd/r9 by an inline
asm routine. Note there is no set routine added for ARM at the
moment, since most if not all updates of gd from c are actually
not needed for ARM.
[1] http://clang.llvm.org/docs/UsersManual.html
cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/include/asm/global_data.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h index 63e4ad5a67..c69d0646f5 100644 --- a/arch/arm/include/asm/global_data.h +++ b/arch/arm/include/asm/global_data.h @@ -44,10 +44,35 @@ struct arch_global_data { #include <asm-generic/global_data.h> +#ifdef __clang__ + +#define DECLARE_GLOBAL_DATA_PTR +#define gd get_gd() + +static inline gd_t *get_gd(void) +{ + gd_t *gd_ptr; + +#ifdef CONFIG_ARM64 + /* + * Make will already error that reserving x18 is not supported at the + * time of writing, clang: error: unknown argument: '-ffixed-x18' + */ + __asm__ volatile("mov %0, x18\n" : "=r" (gd_ptr)); +#else + __asm__ volatile("mov %0, r9\n" : "=r" (gd_ptr)); +#endif + + return gd_ptr; +} + +#else + #ifdef CONFIG_ARM64 #define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("x18") #else #define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("r9") #endif +#endif #endif /* __ASM_GBL_DATA_H */ |