Merge tag 'bitmap-for-6.7' of https://github.com/norov/linux

Pull bitmap updates from Yury Norov:
 "This includes the 'bitmap: cleanup bitmap_*_region() implementation'
  series, and scattered cleanup patches"

* tag 'bitmap-for-6.7' of https://github.com/norov/linux:
  buildid: reduce header file dependencies for module
  bitmap: move bitmap_*_region() functions to bitmap.h
  bitmap: drop _reg_op() function
  bitmap: replace _reg_op(REG_OP_ISFREE) with find_next_bit()
  bitmap: replace _reg_op(REG_OP_RELEASE) with bitmap_clear()
  bitmap: replace _reg_op(REG_OP_ALLOC) with bitmap_set()
  bitmap: fix opencoded bitmap_allocate_region()
  bitmap: add test for bitmap_*_region() functions
  bitmap: align __reg_op() wrappers with modern coding style
  lib/bitmap: split-out string-related operations to a separate files
  bitmap: Remove dead code, i.e. bitmap_copy_le()
  bitmap: Fix a typo ("identify map")
  cpumask: kernel-doc cleanups and additions

MAINTAINERS

@@ -3539,12 +3539,14 @@ R:	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
 R:	Rasmus Villemoes <linux@rasmusvillemoes.dk>
 S:	Maintained
 F:	include/linux/bitfield.h
+F:	include/linux/bitmap-str.h
 F:	include/linux/bitmap.h
 F:	include/linux/bits.h
 F:	include/linux/cpumask.h
 F:	include/linux/find.h
 F:	include/linux/nodemask.h
 F:	include/vdso/bits.h
+F:	lib/bitmap-str.c
 F:	lib/bitmap.c
 F:	lib/cpumask.c
 F:	lib/cpumask_kunit.c

include/linux/bitmap-str.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_BITMAP_STR_H
+#define __LINUX_BITMAP_STR_H
+
+int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, unsigned long *dst, int nbits);
+int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, int nmaskbits);
+extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp,
+					int nmaskbits, loff_t off, size_t count);
+extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp,
+					int nmaskbits, loff_t off, size_t count);
+int bitmap_parse(const char *buf, unsigned int buflen, unsigned long *dst, int nbits);
+int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits);
+int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
+					unsigned long *dst, int nbits);
+
+#endif /* __LINUX_BITMAP_STR_H */

include/linux/bitmap.h

@@ -6,10 +6,12 @@
 
 #include <linux/align.h>
 #include <linux/bitops.h>
+#include <linux/errno.h>
 #include <linux/find.h>
 #include <linux/limits.h>
 #include <linux/string.h>
 #include <linux/types.h>
+#include <linux/bitmap-str.h>
 
 struct device;
 
@@ -200,14 +202,6 @@ bitmap_find_next_zero_area(unsigned long *map,
 					      align_mask, 0);
 }
 
-int bitmap_parse(const char *buf, unsigned int buflen,
-			unsigned long *dst, int nbits);
-int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
-			unsigned long *dst, int nbits);
-int bitmap_parselist(const char *buf, unsigned long *maskp,
-			int nmaskbits);
-int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
-			unsigned long *dst, int nbits);
 void bitmap_remap(unsigned long *dst, const unsigned long *src,
 		const unsigned long *old, const unsigned long *new, unsigned int nbits);
 int bitmap_bitremap(int oldbit,
@@ -216,23 +210,6 @@ void bitmap_onto(unsigned long *dst, const unsigned long *orig,
 		const unsigned long *relmap, unsigned int bits);
 void bitmap_fold(unsigned long *dst, const unsigned long *orig,
 		unsigned int sz, unsigned int nbits);
-int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
-void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
-int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
-
-#ifdef __BIG_ENDIAN
-void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
-#else
-#define bitmap_copy_le bitmap_copy
-#endif
-int bitmap_print_to_pagebuf(bool list, char *buf,
-				   const unsigned long *maskp, int nmaskbits);
-
-extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp,
-				      int nmaskbits, loff_t off, size_t count);
-
-extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp,
-				      int nmaskbits, loff_t off, size_t count);
 
 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
@@ -518,6 +495,66 @@ static inline void bitmap_next_set_region(unsigned long *bitmap,
 	*re = find_next_zero_bit(bitmap, end, *rs + 1);
 }
 
+/**
+ * bitmap_release_region - release allocated bitmap region
+ *	@bitmap: array of unsigned longs corresponding to the bitmap
+ *	@pos: beginning of bit region to release
+ *	@order: region size (log base 2 of number of bits) to release
+ *
+ * This is the complement to __bitmap_find_free_region() and releases
+ * the found region (by clearing it in the bitmap).
+ */
+static inline void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
+{
+	bitmap_clear(bitmap, pos, BIT(order));
+}
+
+/**
+ * bitmap_allocate_region - allocate bitmap region
+ *	@bitmap: array of unsigned longs corresponding to the bitmap
+ *	@pos: beginning of bit region to allocate
+ *	@order: region size (log base 2 of number of bits) to allocate
+ *
+ * Allocate (set bits in) a specified region of a bitmap.
+ *
+ * Returns: 0 on success, or %-EBUSY if specified region wasn't
+ * free (not all bits were zero).
+ */
+static inline int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
+{
+	unsigned int len = BIT(order);
+
+	if (find_next_bit(bitmap, pos + len, pos) < pos + len)
+		return -EBUSY;
+	bitmap_set(bitmap, pos, len);
+	return 0;
+}
+
+/**
+ * bitmap_find_free_region - find a contiguous aligned mem region
+ *	@bitmap: array of unsigned longs corresponding to the bitmap
+ *	@bits: number of bits in the bitmap
+ *	@order: region size (log base 2 of number of bits) to find
+ *
+ * Find a region of free (zero) bits in a @bitmap of @bits bits and
+ * allocate them (set them to one).  Only consider regions of length
+ * a power (@order) of two, aligned to that power of two, which
+ * makes the search algorithm much faster.
+ *
+ * Returns: the bit offset in bitmap of the allocated region,
+ * or -errno on failure.
+ */
+static inline int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
+{
+	unsigned int pos, end;		/* scans bitmap by regions of size order */
+
+	for (pos = 0; (end = pos + BIT(order)) <= bits; pos = end) {
+		if (!bitmap_allocate_region(bitmap, pos, order))
+			return pos;
+	}
+	return -ENOMEM;
+}
+
 /**
  * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
  * @n: u64 value

include/linux/buildid.h

@@ -2,10 +2,11 @@
 #ifndef _LINUX_BUILDID_H
 #define _LINUX_BUILDID_H
 
-#include <linux/mm_types.h>
+#include <linux/types.h>
 
 #define BUILD_ID_SIZE_MAX 20
 
+struct vm_area_struct;
 int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id,
 		   __u32 *size);
 int build_id_parse_buf(const void *buf, unsigned char *build_id, u32 buf_size);

lib/Makefile

@@ -48,7 +48,7 @@ obj-y += bcd.o sort.o parser.o debug_locks.o random32.o \
 	 bsearch.o find_bit.o llist.o lwq.o memweight.o kfifo.o \
 	 percpu-refcount.o rhashtable.o base64.o \
 	 once.o refcount.o rcuref.o usercopy.o errseq.o bucket_locks.o \
-	 generic-radix-tree.o
+	 generic-radix-tree.o bitmap-str.o
 obj-$(CONFIG_STRING_SELFTEST) += test_string.o
 obj-y += string_helpers.o
 obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o

lib/cpumask.c

@@ -14,7 +14,7 @@
  * @start: the start point of the iteration
  * @wrap: assume @n crossing @start terminates the iteration
  *
- * Returns >= nr_cpu_ids on completion
+ * Return: >= nr_cpu_ids on completion
  *
  * Note: the @wrap argument is required for the start condition when
  * we cannot assume @start is set in @mask.
@@ -48,8 +48,9 @@ EXPORT_SYMBOL(cpumask_next_wrap);
  * @node: memory node from which to allocate or %NUMA_NO_NODE
  *
  * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
- * a nop returning a constant 1 (in <linux/cpumask.h>)
- * Returns TRUE if memory allocation succeeded, FALSE otherwise.
+ * a nop returning a constant 1 (in <linux/cpumask.h>).
+ *
+ * Return: TRUE if memory allocation succeeded, FALSE otherwise.
  *
  * In addition, mask will be NULL if this fails.  Note that gcc is
  * usually smart enough to know that mask can never be NULL if
@@ -115,7 +116,7 @@ void __init free_bootmem_cpumask_var(cpumask_var_t mask)
  * @i: index number
  * @node: local numa_node
  *
- * Returns online CPU according to a numa aware policy; local cpus are returned
+ * Return: online CPU according to a numa aware policy; local cpus are returned
  * first, followed by non-local ones, then it wraps around.
  *
  * For those who wants to enumerate all CPUs based on their NUMA distances,
@@ -163,7 +164,7 @@ static DEFINE_PER_CPU(int, distribute_cpu_mask_prev);
  * Iterated calls using the same srcp1 and srcp2 will be distributed within
  * their intersection.
  *
- * Returns >= nr_cpu_ids if the intersection is empty.
+ * Return: >= nr_cpu_ids if the intersection is empty.
  */
 unsigned int cpumask_any_and_distribute(const struct cpumask *src1p,
 			       const struct cpumask *src2p)
@@ -182,6 +183,12 @@ unsigned int cpumask_any_and_distribute(const struct cpumask *src1p,
 }
 EXPORT_SYMBOL(cpumask_any_and_distribute);
 
+/**
+ * cpumask_any_distribute - Return an arbitrary cpu from srcp
+ * @srcp: &cpumask for selection
+ *
+ * Return: >= nr_cpu_ids if the intersection is empty.
+ */
 unsigned int cpumask_any_distribute(const struct cpumask *srcp)
 {
 	unsigned int next, prev;

lib/test_bitmap.c

@@ -330,6 +330,29 @@ static void __init test_copy(void)
 	expect_eq_pbl("0-108,128-1023", bmap2, 1024);
 }
 
+static void __init test_bitmap_region(void)
+{
+	int pos, order;
+
+	DECLARE_BITMAP(bmap, 1000);
+
+	bitmap_zero(bmap, 1000);
+
+	for (order = 0; order < 10; order++) {
+		pos = bitmap_find_free_region(bmap, 1000, order);
+		if (order == 0)
+			expect_eq_uint(pos, 0);
+		else
+			expect_eq_uint(pos, order < 9 ? BIT(order) : -ENOMEM);
+	}
+
+	bitmap_release_region(bmap, 0, 0);
+	for (order = 1; order < 9; order++)
+		bitmap_release_region(bmap, BIT(order), order);
+
+	expect_eq_uint(bitmap_weight(bmap, 1000), 0);
+}
+
 #define EXP2_IN_BITS	(sizeof(exp2) * 8)
 
 static void __init test_replace(void)
@@ -1227,6 +1250,7 @@ static void __init selftest(void)
 	test_zero_clear();
 	test_fill_set();
 	test_copy();
+	test_bitmap_region();
 	test_replace();
 	test_bitmap_arr32();
 	test_bitmap_arr64();