[PATCH 04/14] lib: introduce BITS_{FIRST,LAST} macro

From: Yury Norov
Date: Wed Feb 17 2021 - 23:08:10 EST

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BITMAP_{LAST,FIRST}_WORD_MASK() in linux/bitmap.h duplicates the
functionality of GENMASK(). The scope of there macros is wider
than just bitmap. This patch defines 4 new macros: BITS_FIRST(),
BITS_LAST(), BITS_FIRST_MASK() and BITS_LAST_MASK() in linux/bits.h
on top of GENMASK() and replaces BITMAP_{LAST,FIRST}_WORD_MASK()
to avoid duplication and increase the scope of the macros.

Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
---
include/linux/bitmap.h | 27 ++++++++++++---------------
include/linux/bits.h | 6 ++++++
include/linux/cpumask.h | 8 ++++----
include/linux/netdev_features.h | 2 +-
include/linux/nodemask.h | 2 +-
lib/bitmap.c | 26 +++++++++++++-------------
lib/find_bit.c | 4 ++--
lib/genalloc.c | 8 ++++----
8 files changed, 43 insertions(+), 40 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 70a932470b2d..adf7bd9f0467 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -219,9 +219,6 @@ extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int
extern int bitmap_print_to_pagebuf(bool list, char *buf,
const unsigned long *maskp, int nmaskbits);

-#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
-#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
-
/*
* The static inlines below do not handle constant nbits==0 correctly,
* so make such users (should any ever turn up) call the out-of-line
@@ -257,7 +254,7 @@ static inline void bitmap_copy_clear_tail(unsigned long *dst,
{
bitmap_copy(dst, src, nbits);
if (nbits % BITS_PER_LONG)
- dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
+ dst[nbits / BITS_PER_LONG] &= BITS_FIRST_MASK(nbits - 1);
}

/*
@@ -282,7 +279,7 @@ static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
const unsigned long *src2, unsigned int nbits)
{
if (small_const_nbits(nbits))
- return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
+ return (*dst = *src1 & *src2 & BITS_FIRST(nbits - 1)) != 0;
return __bitmap_and(dst, src1, src2, nbits);
}

@@ -308,7 +305,7 @@ static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
const unsigned long *src2, unsigned int nbits)
{
if (small_const_nbits(nbits))
- return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
+ return (*dst = *src1 & ~(*src2) & BITS_FIRST(nbits - 1)) != 0;
return __bitmap_andnot(dst, src1, src2, nbits);
}

@@ -332,7 +329,7 @@ static inline int bitmap_equal(const unsigned long *src1,
const unsigned long *src2, unsigned int nbits)
{
if (small_const_nbits(nbits))
- return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
+ return !((*src1 ^ *src2) & BITS_FIRST(nbits - 1));
if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
return !memcmp(src1, src2, nbits / 8);
@@ -356,14 +353,14 @@ static inline bool bitmap_or_equal(const unsigned long *src1,
if (!small_const_nbits(nbits))
return __bitmap_or_equal(src1, src2, src3, nbits);

- return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
+ return !(((*src1 | *src2) ^ *src3) & BITS_FIRST(nbits - 1));
}

static inline int bitmap_intersects(const unsigned long *src1,
const unsigned long *src2, unsigned int nbits)
{
if (small_const_nbits(nbits))
- return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
+ return ((*src1 & *src2) & BITS_FIRST(nbits - 1)) != 0;
else
return __bitmap_intersects(src1, src2, nbits);
}
@@ -372,7 +369,7 @@ static inline int bitmap_subset(const unsigned long *src1,
const unsigned long *src2, unsigned int nbits)
{
if (small_const_nbits(nbits))
- return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
+ return !((*src1 & ~(*src2)) & BITS_FIRST(nbits - 1));
else
return __bitmap_subset(src1, src2, nbits);
}
@@ -380,7 +377,7 @@ static inline int bitmap_subset(const unsigned long *src1,
static inline bool bitmap_empty(const unsigned long *src, unsigned nbits)
{
if (small_const_nbits(nbits))
- return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
+ return !(*src & BITS_FIRST(nbits - 1));

return find_first_bit(src, nbits) == nbits;
}
@@ -388,7 +385,7 @@ static inline bool bitmap_empty(const unsigned long *src, unsigned nbits)
static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
{
if (small_const_nbits(nbits))
- return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
+ return !(~(*src) & BITS_FIRST(nbits - 1));

return find_first_zero_bit(src, nbits) == nbits;
}
@@ -396,7 +393,7 @@ static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
{
if (small_const_nbits(nbits))
- return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
+ return hweight_long(*src & BITS_FIRST(nbits - 1));
return __bitmap_weight(src, nbits);
}

@@ -432,7 +429,7 @@ static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *s
unsigned int shift, unsigned int nbits)
{
if (small_const_nbits(nbits))
- *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
+ *dst = (*src & BITS_FIRST(nbits - 1)) >> shift;
else
__bitmap_shift_right(dst, src, shift, nbits);
}
@@ -441,7 +438,7 @@ static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *sr
unsigned int shift, unsigned int nbits)
{
if (small_const_nbits(nbits))
- *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
+ *dst = (*src << shift) & BITS_FIRST(nbits - 1);
else
__bitmap_shift_left(dst, src, shift, nbits);
}
diff --git a/include/linux/bits.h b/include/linux/bits.h
index 7f475d59a097..8c191c29506e 100644
--- a/include/linux/bits.h
+++ b/include/linux/bits.h
@@ -37,6 +37,12 @@
#define GENMASK(h, l) \
(GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))

+#define BITS_FIRST(nr) GENMASK((nr), 0)
+#define BITS_LAST(nr) GENMASK(BITS_PER_LONG - 1, (nr))
+
+#define BITS_FIRST_MASK(nr) BITS_FIRST((nr) % BITS_PER_LONG)
+#define BITS_LAST_MASK(nr) BITS_LAST((nr) % BITS_PER_LONG)
+
#define __GENMASK_ULL(h, l) \
(((~ULL(0)) - (ULL(1) << (l)) + 1) & \
(~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 383684e30f12..edf8d15cfd81 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -899,7 +899,7 @@ static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
#if NR_CPUS <= BITS_PER_LONG
#define CPU_BITS_ALL \
{ \
- [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
+ [BITS_TO_LONGS(NR_CPUS)-1] = BITS_FIRST_MASK(NR_CPUS - 1) \
}

#else /* NR_CPUS > BITS_PER_LONG */
@@ -907,7 +907,7 @@ static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
#define CPU_BITS_ALL \
{ \
[0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
- [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
+ [BITS_TO_LONGS(NR_CPUS)-1] = BITS_FIRST_MASK(NR_CPUS - 1) \
}
#endif /* NR_CPUS > BITS_PER_LONG */

@@ -931,13 +931,13 @@ cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
#if NR_CPUS <= BITS_PER_LONG
#define CPU_MASK_ALL \
(cpumask_t) { { \
- [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
+ [BITS_TO_LONGS(NR_CPUS)-1] = BITS_FIRST_MASK(NR_CPUS - 1) \
} }
#else
#define CPU_MASK_ALL \
(cpumask_t) { { \
[0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \
- [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \
+ [BITS_TO_LONGS(NR_CPUS)-1] = BITS_FIRST_MASK(NR_CPUS - 1) \
} }
#endif /* NR_CPUS > BITS_PER_LONG */

diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index 3de38d6a0aea..4cef7fe02f09 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -173,7 +173,7 @@ enum {
*/
static inline int find_next_netdev_feature(u64 feature, unsigned long start)
{
- /* like BITMAP_LAST_WORD_MASK() for u64
+ /* like BITS_FIRST_MASK() for u64
* this sets the most significant 64 - start to 0.
*/
feature &= ~0ULL >> (-start & ((sizeof(feature) * 8) - 1));
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index ac398e143c9a..2df0787c9155 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -302,7 +302,7 @@ static inline int __first_unset_node(const nodemask_t *maskp)
find_first_zero_bit(maskp->bits, MAX_NUMNODES));
}

-#define NODE_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(MAX_NUMNODES)
+#define NODE_MASK_LAST_WORD BITS_FIRST_MASK(MAX_NUMNODES - 1)

#if MAX_NUMNODES <= BITS_PER_LONG

diff --git a/lib/bitmap.c b/lib/bitmap.c
index 75006c4036e9..2507fef664ad 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -52,7 +52,7 @@ int __bitmap_equal(const unsigned long *bitmap1,
return 0;

if (bits % BITS_PER_LONG)
- if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
+ if ((bitmap1[k] ^ bitmap2[k]) & BITS_FIRST_MASK(bits - 1))
return 0;

return 1;
@@ -76,7 +76,7 @@ bool __bitmap_or_equal(const unsigned long *bitmap1,
return true;

tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k];
- return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0;
+ return (tmp & BITS_FIRST_MASK(bits - 1)) == 0;
}

void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
@@ -103,7 +103,7 @@ void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
{
unsigned k, lim = BITS_TO_LONGS(nbits);
unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
- unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
+ unsigned long mask = BITS_FIRST_MASK(nbits - 1);
for (k = 0; off + k < lim; ++k) {
unsigned long upper, lower;

@@ -246,7 +246,7 @@ int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
result |= (dst[k] = bitmap1[k] & bitmap2[k]);
if (bits % BITS_PER_LONG)
result |= (dst[k] = bitmap1[k] & bitmap2[k] &
- BITMAP_LAST_WORD_MASK(bits));
+ BITS_FIRST_MASK(bits - 1));
return result != 0;
}
EXPORT_SYMBOL(__bitmap_and);
@@ -284,7 +284,7 @@ int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
if (bits % BITS_PER_LONG)
result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
- BITMAP_LAST_WORD_MASK(bits));
+ BITS_FIRST_MASK(bits - 1));
return result != 0;
}
EXPORT_SYMBOL(__bitmap_andnot);
@@ -310,7 +310,7 @@ int __bitmap_intersects(const unsigned long *bitmap1,
return 1;

if (bits % BITS_PER_LONG)
- if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
+ if ((bitmap1[k] & bitmap2[k]) & BITS_FIRST_MASK(bits - 1))
return 1;
return 0;
}
@@ -325,7 +325,7 @@ int __bitmap_subset(const unsigned long *bitmap1,
return 0;

if (bits % BITS_PER_LONG)
- if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
+ if ((bitmap1[k] & ~bitmap2[k]) & BITS_FIRST_MASK(bits - 1))
return 0;
return 1;
}
@@ -340,7 +340,7 @@ int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
w += hweight_long(bitmap[k]);

if (bits % BITS_PER_LONG)
- w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
+ w += hweight_long(bitmap[k] & BITS_FIRST_MASK(bits - 1));

return w;
}
@@ -351,7 +351,7 @@ void __bitmap_set(unsigned long *map, unsigned int start, int len)
unsigned long *p = map + BIT_WORD(start);
const unsigned int size = start + len;
int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
- unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
+ unsigned long mask_to_set = BITS_LAST_MASK(start);

while (len - bits_to_set >= 0) {
*p |= mask_to_set;
@@ -361,7 +361,7 @@ void __bitmap_set(unsigned long *map, unsigned int start, int len)
p++;
}
if (len) {
- mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+ mask_to_set &= BITS_FIRST_MASK(size - 1);
*p |= mask_to_set;
}
}
@@ -372,7 +372,7 @@ void __bitmap_clear(unsigned long *map, unsigned int start, int len)
unsigned long *p = map + BIT_WORD(start);
const unsigned int size = start + len;
int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
- unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
+ unsigned long mask_to_clear = BITS_LAST_MASK(start);

while (len - bits_to_clear >= 0) {
*p &= ~mask_to_clear;
@@ -382,7 +382,7 @@ void __bitmap_clear(unsigned long *map, unsigned int start, int len)
p++;
}
if (len) {
- mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+ mask_to_clear &= BITS_FIRST_MASK(size - 1);
*p &= ~mask_to_clear;
}
}
@@ -1282,7 +1282,7 @@ void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits

/* Clear tail bits in last word beyond nbits. */
if (nbits % BITS_PER_LONG)
- bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits);
+ bitmap[(halfwords - 1) / 2] &= BITS_FIRST_MASK(nbits - 1);
}
EXPORT_SYMBOL(bitmap_from_arr32);

diff --git a/lib/find_bit.c b/lib/find_bit.c
index f67f86fd2f62..8c2a71a18793 100644
--- a/lib/find_bit.c
+++ b/lib/find_bit.c
@@ -44,7 +44,7 @@ static unsigned long _find_next_bit(const unsigned long *addr1,
tmp ^= invert;

/* Handle 1st word. */
- mask = BITMAP_FIRST_WORD_MASK(start);
+ mask = BITS_LAST_MASK(start);
if (le)
mask = swab(mask);

@@ -141,7 +141,7 @@ EXPORT_SYMBOL(find_first_zero_bit);
unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
{
if (size) {
- unsigned long val = BITMAP_LAST_WORD_MASK(size);
+ unsigned long val = BITS_FIRST_MASK(size - 1);
unsigned long idx = (size-1) / BITS_PER_LONG;

do {
diff --git a/lib/genalloc.c b/lib/genalloc.c
index 5dcf9cdcbc46..0af7275517ff 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -87,7 +87,7 @@ bitmap_set_ll(unsigned long *map, unsigned long start, unsigned long nr)
unsigned long *p = map + BIT_WORD(start);
const unsigned long size = start + nr;
int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
- unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
+ unsigned long mask_to_set = BITS_LAST_MASK(start);

while (nr >= bits_to_set) {
if (set_bits_ll(p, mask_to_set))
@@ -98,7 +98,7 @@ bitmap_set_ll(unsigned long *map, unsigned long start, unsigned long nr)
p++;
}
if (nr) {
- mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+ mask_to_set &= BITS_FIRST_MASK(size - 1);
if (set_bits_ll(p, mask_to_set))
return nr;
}
@@ -123,7 +123,7 @@ bitmap_clear_ll(unsigned long *map, unsigned long start, unsigned long nr)
unsigned long *p = map + BIT_WORD(start);
const unsigned long size = start + nr;
int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
- unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
+ unsigned long mask_to_clear = BITS_LAST_MASK(start);

while (nr >= bits_to_clear) {
if (clear_bits_ll(p, mask_to_clear))
@@ -134,7 +134,7 @@ bitmap_clear_ll(unsigned long *map, unsigned long start, unsigned long nr)
p++;
}
if (nr) {
- mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+ mask_to_clear &= BITS_FIRST_MASK(size - 1);
if (clear_bits_ll(p, mask_to_clear))
return nr;
}
--
2.25.1

Next message: Yury Norov: "[PATCH 06/14] bitsperlong.h: introduce SMALL_CONST() macro"
Previous message: Yury Norov: "[PATCH 05/14] tools: sync BITS_MASK macros with the kernel"
In reply to: Yury Norov: "[PATCH 05/14] tools: sync BITS_MASK macros with the kernel"
Next in thread: Rasmus Villemoes: "Re: [PATCH 04/14] lib: introduce BITS_{FIRST,LAST} macro"
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