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authorLiam Beguin <liambeguin@gmail.com>2020-07-18 16:10:21 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-08-05 10:06:05 +0200
commitddce1f2d9dc2973ccea342b8154a33a6b22fc557 (patch)
tree857c5bb910f87d63311c3f3a8b6b9020c0127a9b /arch/parisc/lib
parent5fa5e4def87289197d7aa04d0c45f0a9fea1a14e (diff)
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parisc: add support for cmpxchg on u8 pointers
[ Upstream commit b344d6a83d01c52fddbefa6b3b4764da5b1022a0 ] The kernel test bot reported[1] that using set_mask_bits on a u8 causes the following issue on parisc: hppa-linux-ld: drivers/phy/ti/phy-tusb1210.o: in function `tusb1210_probe': >> (.text+0x2f4): undefined reference to `__cmpxchg_called_with_bad_pointer' >> hppa-linux-ld: (.text+0x324): undefined reference to `__cmpxchg_called_with_bad_pointer' hppa-linux-ld: (.text+0x354): undefined reference to `__cmpxchg_called_with_bad_pointer' Add support for cmpxchg on u8 pointers. [1] https://lore.kernel.org/patchwork/patch/1272617/#1468946 Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Liam Beguin <liambeguin@gmail.com> Tested-by: Dave Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/parisc/lib')
-rw-r--r--arch/parisc/lib/bitops.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/parisc/lib/bitops.c b/arch/parisc/lib/bitops.c
index 70ffbcf889b8..2e4d1f05a926 100644
--- a/arch/parisc/lib/bitops.c
+++ b/arch/parisc/lib/bitops.c
@@ -79,3 +79,15 @@ unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsign
_atomic_spin_unlock_irqrestore(ptr, flags);
return (unsigned long)prev;
}
+
+u8 __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new)
+{
+ unsigned long flags;
+ u8 prev;
+
+ _atomic_spin_lock_irqsave(ptr, flags);
+ if ((prev = *ptr) == old)
+ *ptr = new;
+ _atomic_spin_unlock_irqrestore(ptr, flags);
+ return prev;
+}