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| author | Mark Brown <broonie@kernel.org> | 2015-01-07 17:30:17 +0000 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2015-01-07 17:30:17 +0000 |
| commit | 1285c3fefaddedf5358f52cfde3c2b64d8086a04 (patch) | |
| tree | 361f556d6b400e8cb6d16738142db2f69f63ef2f /arch/parisc/include/asm/ldcw.h | |
| parent | 6b038c8d2b99b552f0b025c8a134f8a3c417a3e7 (diff) | |
| parent | b1940cd21c0f4abdce101253e860feff547291b0 (diff) | |
| download | op-kernel-dev-1285c3fefaddedf5358f52cfde3c2b64d8086a04.zip op-kernel-dev-1285c3fefaddedf5358f52cfde3c2b64d8086a04.tar.gz | |
Merge tag 'v3.19-rc3' into spi-sh-msiof
Linux 3.19-rc3
Diffstat (limited to 'arch/parisc/include/asm/ldcw.h')
| -rw-r--r-- | arch/parisc/include/asm/ldcw.h | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/arch/parisc/include/asm/ldcw.h b/arch/parisc/include/asm/ldcw.h index d2d11b7..8121aa6 100644 --- a/arch/parisc/include/asm/ldcw.h +++ b/arch/parisc/include/asm/ldcw.h @@ -33,11 +33,18 @@ #endif /*!CONFIG_PA20*/ -/* LDCW, the only atomic read-write operation PA-RISC has. *sigh*. */ +/* LDCW, the only atomic read-write operation PA-RISC has. *sigh*. + We don't explicitly expose that "*a" may be written as reload + fails to find a register in class R1_REGS when "a" needs to be + reloaded when generating 64-bit PIC code. Instead, we clobber + memory to indicate to the compiler that the assembly code reads + or writes to items other than those listed in the input and output + operands. This may pessimize the code somewhat but __ldcw is + usually used within code blocks surrounded by memory barriors. */ #define __ldcw(a) ({ \ unsigned __ret; \ - __asm__ __volatile__(__LDCW " 0(%2),%0" \ - : "=r" (__ret), "+m" (*(a)) : "r" (a)); \ + __asm__ __volatile__(__LDCW " 0(%1),%0" \ + : "=r" (__ret) : "r" (a) : "memory"); \ __ret; \ }) |
