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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-10-27 08:02:50 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-10-27 08:02:50 +0100
commit37022410f4a3cc11614626a58cd08bcf8ea529e9 (patch)
tree60e0a996385b1d5865dc5264ff130cf9e852abb4 /arch/arm64/include/asm/sysreg.h
parentaad1577ab950d1ad46e0dd0915bfbaf9fa9160e4 (diff)
parentdcb6fa37fd7bc9c3d2b066329b0d27dedf8becaa (diff)
Merge 6.18-rc3 into driver-core-next
We need the driver core fixes in here as well to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/include/asm/sysreg.h')
-rw-r--r--arch/arm64/include/asm/sysreg.h11
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 6455db1b54fd..c231d2a3e515 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -1220,10 +1220,19 @@
__val; \
})
+/*
+ * The "Z" constraint combined with the "%x0" template should be enough
+ * to force XZR generation if (v) is a constant 0 value but LLVM does not
+ * yet understand that modifier/constraint combo so a conditional is required
+ * to nudge the compiler into using XZR as a source for a 0 constant value.
+ */
#define write_sysreg_s(v, r) do { \
u64 __val = (u64)(v); \
u32 __maybe_unused __check_r = (u32)(r); \
- asm volatile(__msr_s(r, "%x0") : : "rZ" (__val)); \
+ if (__builtin_constant_p(__val) && __val == 0) \
+ asm volatile(__msr_s(r, "xzr")); \
+ else \
+ asm volatile(__msr_s(r, "%x0") : : "r" (__val)); \
} while (0)
/*