diff options
author | Xi Wang <xi.wang@gmail.com> | 2012-11-16 23:40:03 +0400 |
---|---|---|
committer | James Bottomley <JBottomley@Parallels.com> | 2012-11-30 13:20:17 +0400 |
commit | beecadea1b8d67f591b13f7099559f32f3fd601d (patch) | |
tree | e96c70ef947343902268e9d6d294333f275706aa /drivers/scsi/mvsas/mv_94xx.h | |
parent | 072f19b4bea31cdd482d79f805413f2f9ac9e233 (diff) | |
download | linux-beecadea1b8d67f591b13f7099559f32f3fd601d.tar.xz |
[SCSI] mvsas: fix undefined bit shift
The macro bit(n) is defined as ((u32)1 << n), and thus it doesn't work
with n >= 32, such as in mvs_94xx_assign_reg_set():
if (i >= 32) {
mvi->sata_reg_set |= bit(i);
...
}
The shift ((u32)1 << n) with n >= 32 also leads to undefined behavior.
The result varies depending on the architecture.
This patch changes bit(n) to do a 64-bit shift. It also simplifies
mv_ffc64() using __ffs64(), since invoking ffz() with ~0 is undefined.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Acked-by: Xiangliang Yu <yuxiangl@marvell.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/mvsas/mv_94xx.h')
-rw-r--r-- | drivers/scsi/mvsas/mv_94xx.h | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/drivers/scsi/mvsas/mv_94xx.h b/drivers/scsi/mvsas/mv_94xx.h index 8f7eb4f21140..487aa6f97412 100644 --- a/drivers/scsi/mvsas/mv_94xx.h +++ b/drivers/scsi/mvsas/mv_94xx.h @@ -258,21 +258,11 @@ enum sas_sata_phy_regs { #define SPI_ADDR_VLD_94XX (1U << 1) #define SPI_CTRL_SpiStart_94XX (1U << 0) -#define mv_ffc(x) ffz(x) - static inline int mv_ffc64(u64 v) { - int i; - i = mv_ffc((u32)v); - if (i >= 0) - return i; - i = mv_ffc((u32)(v>>32)); - - if (i != 0) - return 32 + i; - - return -1; + u64 x = ~v; + return x ? __ffs64(x) : -1; } #define r_reg_set_enable(i) \ |