diff options
| author | David S. Miller <davem@davemloft.net> | 2015-05-13 14:31:43 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-05-13 14:31:43 -0400 |
| commit | b04096ff33a977c01c8780ca3ee129dbd641bad4 (patch) | |
| tree | 8652f27f158984e5aa4c00ddf1a4885a32435f28 /include/linux/compiler-gcc.h | |
| parent | 7f460d30c8e130382de1443fdbc4d040a9e062ec (diff) | |
| parent | 110bc76729d448fdbcb5cdb63b83d9fd65ce5e26 (diff) | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Four minor merge conflicts:
1) qca_spi.c renamed the local variable used for the SPI device
from spi_device to spi, meanwhile the spi_set_drvdata() call
got moved further up in the probe function.
2) Two changes were both adding new members to codel params
structure, and thus we had overlapping changes to the
initializer function.
3) 'net' was making a fix to sk_release_kernel() which is
completely removed in 'net-next'.
4) In net_namespace.c, the rtnl_net_fill() call for GET operations
had the command value fixed, meanwhile 'net-next' adjusted the
argument signature a bit.
This also matches example merge resolutions posted by Stephen
Rothwell over the past two days.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/compiler-gcc.h')
| -rw-r--r-- | include/linux/compiler-gcc.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index cdf13ca7cac3..371e560d13cf 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -9,10 +9,24 @@ + __GNUC_MINOR__ * 100 \ + __GNUC_PATCHLEVEL__) - /* Optimization barrier */ + /* The "volatile" is due to gcc bugs */ #define barrier() __asm__ __volatile__("": : :"memory") +/* + * This version is i.e. to prevent dead stores elimination on @ptr + * where gcc and llvm may behave differently when otherwise using + * normal barrier(): while gcc behavior gets along with a normal + * barrier(), llvm needs an explicit input variable to be assumed + * clobbered. The issue is as follows: while the inline asm might + * access any memory it wants, the compiler could have fit all of + * @ptr into memory registers instead, and since @ptr never escaped + * from that, it proofed that the inline asm wasn't touching any of + * it. This version works well with both compilers, i.e. we're telling + * the compiler that the inline asm absolutely may see the contents + * of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495 + */ +#define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory") /* * This macro obfuscates arithmetic on a variable address so that gcc |