>From [1]
"GCC 10 (PR 91233) won't silently allow registers that are not architecturally
available to be present in the clobber list anymore, resulting in build failure
for mips*r6 targets in form of:
...
.../sysdep.h:146:2: error: the register ‘lo’ cannot be clobbered in ‘asm’ for the current target
146 | __asm__ volatile ( \
| ^~~~~~~
This is because base R6 ISA doesn't define hi and lo registers w/o DSP extension.
This patch provides the alternative clobber list for r6 targets that won't include
those registers."
Since kernel 5.4 and mips support for generic vDSO [2], the kernel fail to build
for mips r6 cpus with gcc 10 for the same reason as glibc.
[1] https://sourceware.org/git/?p=glibc.git;a=commit;h=020b2a97bb15f807c0482f0faee2184ed05bcad8
[2] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=24640f233b466051ad3a5d2786d2951e43026c9d
Signed-off-by: Romain Naour <romain.naour@xxxxxxxxx>
---
v3 Avoid duplicate code (Maciej W. Rozycki)
v2 use MIPS_ISA_REV instead of __mips_isa_rev (Alexander Lobakin)
---
arch/mips/include/asm/vdso/gettimeofday.h | 30 +++++++++++++++++++----
1 file changed, 25 insertions(+), 5 deletions(-)
diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h
index c63ddcaea54c..93008551282e 100644
--- a/arch/mips/include/asm/vdso/gettimeofday.h
+++ b/arch/mips/include/asm/vdso/gettimeofday.h
@@ -35,7 +35,11 @@ static __always_inline long gettimeofday_fallback(
: "=r" (ret), "=r" (error)
: "r" (tv), "r" (tz), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
- "$14", "$15", "$24", "$25", "hi", "lo", "memory");
+ "$14", "$15", "$24", "$25",
+#if MIPS_ISA_REV < 6
+ "hi", "lo",
+#endif
+ "memory");
return error ? -ret : ret;
}
@@ -59,7 +63,11 @@ static __always_inline long clock_gettime_fallback(
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
- "$14", "$15", "$24", "$25", "hi", "lo", "memory");
+ "$14", "$15", "$24", "$25",
+#if MIPS_ISA_REV < 6
+ "hi", "lo",
+#endif
+ "memory");
return error ? -ret : ret;
}
@@ -83,7 +91,11 @@ static __always_inline int clock_getres_fallback(
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
- "$14", "$15", "$24", "$25", "hi", "lo", "memory");
+ "$14", "$15", "$24", "$25",
+#if MIPS_ISA_REV < 6
+ "hi", "lo",
+#endif
+ "memory");
return error ? -ret : ret;
}
@@ -105,7 +117,11 @@ static __always_inline long clock_gettime32_fallback(
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
- "$14", "$15", "$24", "$25", "hi", "lo", "memory");
+ "$14", "$15", "$24", "$25",
+#if MIPS_ISA_REV < 6
+ "hi", "lo",
+#endif
+ "memory");
return error ? -ret : ret;
}
@@ -125,7 +141,11 @@ static __always_inline int clock_getres32_fallback(
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
- "$14", "$15", "$24", "$25", "hi", "lo", "memory");
+ "$14", "$15", "$24", "$25",
+#if MIPS_ISA_REV < 6
+ "hi", "lo",
+#endif
+ "memory");
return error ? -ret : ret;
}
--
2.25.4
