[PATCH net-next v5 05/21] bitops: make BYTES_TO_BITS() treewide-available

Alexander Lobakin
2024-02-01T12:23:57Z

Avoid open-coding that simple expression each time by moving
BYTES_TO_BITS() from the probes code to <linux/bitops.h> to export
it to the rest of the kernel.
Simplify the macro while at it. `BITS_PER_LONG / sizeof(long)` always
equals to %BITS_PER_BYTE, regardless of the target architecture.
Do the same for the tools ecosystem as well (incl. its version of
bitops.h). The previous implementation had its implicit type of long,
while the new one is int, so adjust the format literal accordingly in
the perf code.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
include/linux/bitops.h | 2 ++
tools/include/linux/bitops.h | 2 ++
kernel/trace/trace_probe.c | 2 --
tools/perf/util/probe-finder.c | 4 +---
4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index f7f5a783da2a..e0cd09eb91cd 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -21,6 +21,8 @@
#define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
#define BITS_TO_BYTES(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))

+#define BYTES_TO_BITS(nb) ((nb) * BITS_PER_BYTE)
+
extern unsigned int __sw_hweight8(unsigned int w);
extern unsigned int __sw_hweight16(unsigned int w);
extern unsigned int __sw_hweight32(unsigned int w);
diff --git a/tools/include/linux/bitops.h b/tools/include/linux/bitops.h
index f18683b95ea6..bc6600466e7b 100644
--- a/tools/include/linux/bitops.h
+++ b/tools/include/linux/bitops.h
@@ -20,6 +20,8 @@
#define BITS_TO_U32(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
#define BITS_TO_BYTES(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(char))

+#define BYTES_TO_BITS(nb) ((nb) * BITS_PER_BYTE)
+
extern unsigned int __sw_hweight8(unsigned int w);
extern unsigned int __sw_hweight16(unsigned int w);
extern unsigned int __sw_hweight32(unsigned int w);
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 4dc74d73fc1d..2b743c1e37db 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1053,8 +1053,6 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
return ret;
}

-#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
-
/* Bitfield type needs to be parsed into a fetch function */
static int __parse_bitfield_probe_arg(const char *bf,
const struct fetch_type *t,
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index c8923375e30d..630e16c54ed5 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -186,8 +186,6 @@ static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr,
return ret2;
}

-#define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
-
static int convert_variable_type(Dwarf_Die *vr_die,
struct probe_trace_arg *tvar,
const char *cast, bool user_access)
@@ -217,7 +215,7 @@ static int convert_variable_type(Dwarf_Die *vr_die,
total = dwarf_bytesize(vr_die);
if (boffs < 0 || total < 0)
return -ENOENT;
- ret = snprintf(buf, 16, "b%d@%d/%zd", bsize, boffs,
+ ret = snprintf(buf, 16, "b%d@%d/%d", bsize, boffs,
BYTES_TO_BITS(total));
goto formatted;
}
--
2.43.0