diff options
| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-05-28 10:18:17 +1000 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2008-05-31 17:08:28 +1000 |
| commit | cfab3bdf8292edec19492c89520b1ad11279a648 (patch) | |
| tree | dbc3ed8bf7173b102bf844ed8121941b0b2303d8 | |
| parent | 732bee4c859012edf05f3e09b53b68fc332a369d (diff) | |
[POWERPC] Add "memory" clobber to MMIO accessors
Gcc might re-order MMIO accessors vs. surrounding consistent
memory accesses, which is a "bad thing", and could break drivers.
This fixes it by adding a "memory" clobber to the MMIO accessors,
which should prevent gcc from doing that reordering.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
| -rw-r--r-- | include/asm-powerpc/io.h | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/include/asm-powerpc/io.h b/include/asm-powerpc/io.h index e0062d73db1c..89189488e286 100644 --- a/include/asm-powerpc/io.h +++ b/include/asm-powerpc/io.h @@ -100,7 +100,7 @@ static inline type name(const volatile type __iomem *addr) \ { \ type ret; \ __asm__ __volatile__("sync;" insn ";twi 0,%0,0;isync" \ - : "=r" (ret) : "r" (addr), "m" (*addr)); \ + : "=r" (ret) : "r" (addr), "m" (*addr) : "memory"); \ return ret; \ } @@ -108,8 +108,8 @@ static inline type name(const volatile type __iomem *addr) \ static inline void name(volatile type __iomem *addr, type val) \ { \ __asm__ __volatile__("sync;" insn \ - : "=m" (*addr) : "r" (val), "r" (addr)); \ - IO_SET_SYNC_FLAG(); \ + : "=m" (*addr) : "r" (val), "r" (addr) : "memory"); \ + IO_SET_SYNC_FLAG(); \ } @@ -333,7 +333,8 @@ static inline unsigned int name(unsigned int port) \ " .long 3b,5b\n" \ ".previous" \ : "=&r" (x) \ - : "r" (port + _IO_BASE)); \ + : "r" (port + _IO_BASE) \ + : "memory"); \ return x; \ } @@ -350,7 +351,8 @@ static inline void name(unsigned int val, unsigned int port) \ " .long 0b,2b\n" \ " .long 1b,2b\n" \ ".previous" \ - : : "r" (val), "r" (port + _IO_BASE)); \ + : : "r" (val), "r" (port + _IO_BASE) \ + : "memory"); \ } __do_in_asm(_rec_inb, "lbzx") |