Exactly as per ffs() in the previous patch. Express the upper bound of the
testing in terms of BITS_PER_LONG as it varies between architectures.
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
---
CC: Jan Beulich <jbeul...@suse.com>
CC: Roger Pau Monné <roger....@citrix.com>
CC: Wei Liu <w...@xen.org>
CC: Stefano Stabellini <sstabell...@kernel.org>
CC: Julien Grall <jul...@xen.org>
CC: Volodymyr Babchuk <volodymyr_babc...@epam.com>
CC: Bertrand Marquis <bertrand.marq...@arm.com>
CC: Michal Orzel <michal.or...@amd.com>
CC: Oleksii Kurochko <oleksii.kuroc...@gmail.com>
CC: Shawn Anastasio <sanasta...@raptorengineering.com>
CC: consult...@bugseng.com <consult...@bugseng.com>
CC: Simone Ballarin <simone.balla...@bugseng.com>
CC: Federico Serafini <federico.seraf...@bugseng.com>
CC: Nicola Vetrini <nicola.vetr...@bugseng.com>
---
xen/arch/arm/include/asm/bitops.h | 2 +-
xen/arch/ppc/include/asm/bitops.h | 1 -
xen/arch/x86/include/asm/bitops.h | 30 +++++++++++++-----------------
xen/common/bitops.c | 7 +++++++
xen/include/xen/bitops.h | 12 ++++++++++++
5 files changed, 33 insertions(+), 19 deletions(-)
diff --git a/xen/arch/arm/include/asm/bitops.h
b/xen/arch/arm/include/asm/bitops.h
index 09c6064274a7..59ae8ed150b6 100644
--- a/xen/arch/arm/include/asm/bitops.h
+++ b/xen/arch/arm/include/asm/bitops.h
@@ -158,7 +158,7 @@ static inline int fls(unsigned int x)
#define arch_ffs(x) ({ unsigned int __t = (x); fls(ISOLATE_LSB(__t)); })
-#define ffsl(x) ({ unsigned long __t = (x); flsl(ISOLATE_LSB(__t)); })
+#define arch_ffsl(x) ({ unsigned long __t = (x); flsl(ISOLATE_LSB(__t)); })
/**
* find_first_set_bit - find the first set bit in @word
diff --git a/xen/arch/ppc/include/asm/bitops.h
b/xen/arch/ppc/include/asm/bitops.h
index 635a3b4e3e33..ecec2a826660 100644
--- a/xen/arch/ppc/include/asm/bitops.h
+++ b/xen/arch/ppc/include/asm/bitops.h
@@ -173,7 +173,6 @@ static inline int __test_and_clear_bit(int nr, volatile
void *addr)
#define flsl(x) generic_flsl(x)
#define fls(x) generic_fls(x)
-#define ffsl(x) ({ unsigned long t_ = (x); flsl(t_ & -t_); })
/* Based on linux/include/asm-generic/bitops/ffz.h */
/*
diff --git a/xen/arch/x86/include/asm/bitops.h
b/xen/arch/x86/include/asm/bitops.h
index 2c5b103cbbd9..99342877e32f 100644
--- a/xen/arch/x86/include/asm/bitops.h
+++ b/xen/arch/x86/include/asm/bitops.h
@@ -413,23 +413,6 @@ static inline unsigned int find_first_set_bit(unsigned
long word)
return (unsigned int)word;
}
-/**
- * ffs - find first bit set
- * @x: the word to search
- *
- * This is defined the same way as the libc and compiler builtin ffs routines.
- */
-static inline int ffsl(unsigned long x)
-{
- long r;
-
- asm ( "bsf %1,%0\n\t"
- "jnz 1f\n\t"
- "mov $-1,%0\n"
- "1:" : "=r" (r) : "rm" (x));
- return (int)r+1;
-}
-
static inline unsigned int arch_ffs(unsigned int x)
{
int r = -1;
@@ -448,6 +431,19 @@ static inline unsigned int arch_ffs(unsigned int x)
}
#define arch_ffs arch_ffs
+static inline unsigned int arch_ffsl(unsigned long x)
+{
+ long r = -1;
+
+ /* See arch_ffs() for safety discussion. */
+ asm ( "bsf %[val], %[res]"
+ : [res] "+r" (r)
+ : [val] "rm" (x) );
+
+ return r + 1;
+}
+#define arch_ffsl arch_ffsl
+
/**
* fls - find last bit set
* @x: the word to search
diff --git a/xen/common/bitops.c b/xen/common/bitops.c
index 484df68768ad..eceffe5029d6 100644
--- a/xen/common/bitops.c
+++ b/xen/common/bitops.c
@@ -40,6 +40,13 @@ static void test_ffs(void)
CHECK(ffs, 0, 0);
CHECK(ffs, 1, 1);
CHECK(ffs, 0x80000000U, 32);
+
+ /* unsigned int ffsl(unsigned long) */
+ CHECK(ffsl, 0, 0);
+ CHECK(ffsl, 1, 1);
+ CHECK(ffsl, 1UL << (BITS_PER_LONG - 1), BITS_PER_LONG);
+ if ( BITS_PER_LONG > 32 )
+ CHECK(ffsl, 1UL << 32, 33);
}
static int __init cf_check test_bitops(void)
diff --git a/xen/include/xen/bitops.h b/xen/include/xen/bitops.h
index fb3645d9cf87..a37b42342bc5 100644
--- a/xen/include/xen/bitops.h
+++ b/xen/include/xen/bitops.h
@@ -125,6 +125,18 @@ static always_inline __pure unsigned int ffs(unsigned int
x)
return arch_ffs(x);
}
+static always_inline __pure unsigned int ffsl(unsigned long x)
+{
+ if ( __builtin_constant_p(x) )
+ return __builtin_ffsl(x);
+
+#ifndef arch_ffsl
+#define arch_ffsl __builtin_ffsl
+#endif
+
+ return arch_ffsl(x);
+}
+
/* --------------------- Please tidy below here --------------------- */
#ifndef find_next_bit
--
2.30.2
