From 57f728d59f005dffdbb52a03531e480a71599bc5 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Mon, 31 Jul 2023 22:08:17 -0700 Subject: [PATCH 01/13] cpumask: kernel-doc cleanups and additions Clean up some punctutation and abbreviations. Add kernel-doc notation for one function and function return value for 39 functions. cpumask.h: Fix some punctuation (plural vs. possessive). Fix some abbreviations (ie. -> i.e., id -> ID). Fix 35 warnings like this: include/linux/cpumask.h:161: warning: No description found for return value of 'cpumask_first' cpumask.c: Add Return: value for 4 functions. Add kernel-doc for cpumask_any_distribute(). Signed-off-by: Randy Dunlap Reviewed-by: Andy Shevchenko Signed-off-by: Yury Norov --- include/linux/cpumask.h | 113 ++++++++++++++++++++++++---------------- lib/cpumask.c | 17 ++++-- 2 files changed, 81 insertions(+), 49 deletions(-) diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index f10fb87d49db..cfb545841a2c 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -4,7 +4,7 @@ /* * Cpumasks provide a bitmap suitable for representing the - * set of CPU's in a system, one bit position per CPU number. In general, + * set of CPUs in a system, one bit position per CPU number. In general, * only nr_cpu_ids (<= NR_CPUS) bits are valid. */ #include @@ -97,7 +97,7 @@ static inline void set_nr_cpu_ids(unsigned int nr) * * If !CONFIG_HOTPLUG_CPU, present == possible, and active == online. * - * The cpu_possible_mask is fixed at boot time, as the set of CPU id's + * The cpu_possible_mask is fixed at boot time, as the set of CPU IDs * that it is possible might ever be plugged in at anytime during the * life of that system boot. The cpu_present_mask is dynamic(*), * representing which CPUs are currently plugged in. And @@ -112,7 +112,7 @@ static inline void set_nr_cpu_ids(unsigned int nr) * hotplug, it's a copy of cpu_possible_mask, hence fixed at boot. * * Subtleties: - * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode + * 1) UP ARCHes (NR_CPUS == 1, CONFIG_SMP not defined) hardcode * assumption that their single CPU is online. The UP * cpu_{online,possible,present}_masks are placebos. Changing them * will have no useful affect on the following num_*_cpus() @@ -155,7 +155,7 @@ static __always_inline unsigned int cpumask_check(unsigned int cpu) * cpumask_first - get the first cpu in a cpumask * @srcp: the cpumask pointer * - * Returns >= nr_cpu_ids if no cpus set. + * Return: >= nr_cpu_ids if no cpus set. */ static inline unsigned int cpumask_first(const struct cpumask *srcp) { @@ -166,7 +166,7 @@ static inline unsigned int cpumask_first(const struct cpumask *srcp) * cpumask_first_zero - get the first unset cpu in a cpumask * @srcp: the cpumask pointer * - * Returns >= nr_cpu_ids if all cpus are set. + * Return: >= nr_cpu_ids if all cpus are set. */ static inline unsigned int cpumask_first_zero(const struct cpumask *srcp) { @@ -178,7 +178,7 @@ static inline unsigned int cpumask_first_zero(const struct cpumask *srcp) * @srcp1: the first input * @srcp2: the second input * - * Returns >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and(). + * Return: >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and(). */ static inline unsigned int cpumask_first_and(const struct cpumask *srcp1, const struct cpumask *srcp2) @@ -190,7 +190,7 @@ unsigned int cpumask_first_and(const struct cpumask *srcp1, const struct cpumask * cpumask_last - get the last CPU in a cpumask * @srcp: - the cpumask pointer * - * Returns >= nr_cpumask_bits if no CPUs set. + * Return: >= nr_cpumask_bits if no CPUs set. */ static inline unsigned int cpumask_last(const struct cpumask *srcp) { @@ -199,10 +199,10 @@ static inline unsigned int cpumask_last(const struct cpumask *srcp) /** * cpumask_next - get the next cpu in a cpumask - * @n: the cpu prior to the place to search (ie. return will be > @n) + * @n: the cpu prior to the place to search (i.e. return will be > @n) * @srcp: the cpumask pointer * - * Returns >= nr_cpu_ids if no further cpus set. + * Return: >= nr_cpu_ids if no further cpus set. */ static inline unsigned int cpumask_next(int n, const struct cpumask *srcp) @@ -215,10 +215,10 @@ unsigned int cpumask_next(int n, const struct cpumask *srcp) /** * cpumask_next_zero - get the next unset cpu in a cpumask - * @n: the cpu prior to the place to search (ie. return will be > @n) + * @n: the cpu prior to the place to search (i.e. return will be > @n) * @srcp: the cpumask pointer * - * Returns >= nr_cpu_ids if no further cpus unset. + * Return: >= nr_cpu_ids if no further cpus unset. */ static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp) { @@ -254,11 +254,11 @@ unsigned int cpumask_any_distribute(const struct cpumask *srcp); /** * cpumask_next_and - get the next cpu in *src1p & *src2p - * @n: the cpu prior to the place to search (ie. return will be > @n) + * @n: the cpu prior to the place to search (i.e. return will be > @n) * @src1p: the first cpumask pointer * @src2p: the second cpumask pointer * - * Returns >= nr_cpu_ids if no further cpus set in both. + * Return: >= nr_cpu_ids if no further cpus set in both. */ static inline unsigned int cpumask_next_and(int n, const struct cpumask *src1p, @@ -373,7 +373,7 @@ unsigned int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int sta * @cpu: the cpu to ignore. * * Often used to find any cpu but smp_processor_id() in a mask. - * Returns >= nr_cpu_ids if no cpus set. + * Return: >= nr_cpu_ids if no cpus set. */ static inline unsigned int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) @@ -388,11 +388,11 @@ unsigned int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) } /** - * cpumask_nth - get the first cpu in a cpumask + * cpumask_nth - get the Nth cpu in a cpumask * @srcp: the cpumask pointer - * @cpu: the N'th cpu to find, starting from 0 + * @cpu: the Nth cpu to find, starting from 0 * - * Returns >= nr_cpu_ids if such cpu doesn't exist. + * Return: >= nr_cpu_ids if such cpu doesn't exist. */ static inline unsigned int cpumask_nth(unsigned int cpu, const struct cpumask *srcp) { @@ -400,12 +400,12 @@ static inline unsigned int cpumask_nth(unsigned int cpu, const struct cpumask *s } /** - * cpumask_nth_and - get the first cpu in 2 cpumasks + * cpumask_nth_and - get the Nth cpu in 2 cpumasks * @srcp1: the cpumask pointer * @srcp2: the cpumask pointer - * @cpu: the N'th cpu to find, starting from 0 + * @cpu: the Nth cpu to find, starting from 0 * - * Returns >= nr_cpu_ids if such cpu doesn't exist. + * Return: >= nr_cpu_ids if such cpu doesn't exist. */ static inline unsigned int cpumask_nth_and(unsigned int cpu, const struct cpumask *srcp1, @@ -416,12 +416,12 @@ unsigned int cpumask_nth_and(unsigned int cpu, const struct cpumask *srcp1, } /** - * cpumask_nth_andnot - get the first cpu set in 1st cpumask, and clear in 2nd. + * cpumask_nth_andnot - get the Nth cpu set in 1st cpumask, and clear in 2nd. * @srcp1: the cpumask pointer * @srcp2: the cpumask pointer - * @cpu: the N'th cpu to find, starting from 0 + * @cpu: the Nth cpu to find, starting from 0 * - * Returns >= nr_cpu_ids if such cpu doesn't exist. + * Return: >= nr_cpu_ids if such cpu doesn't exist. */ static inline unsigned int cpumask_nth_andnot(unsigned int cpu, const struct cpumask *srcp1, @@ -436,9 +436,9 @@ unsigned int cpumask_nth_andnot(unsigned int cpu, const struct cpumask *srcp1, * @srcp1: the cpumask pointer * @srcp2: the cpumask pointer * @srcp3: the cpumask pointer - * @cpu: the N'th cpu to find, starting from 0 + * @cpu: the Nth cpu to find, starting from 0 * - * Returns >= nr_cpu_ids if such cpu doesn't exist. + * Return: >= nr_cpu_ids if such cpu doesn't exist. */ static __always_inline unsigned int cpumask_nth_and_andnot(unsigned int cpu, const struct cpumask *srcp1, @@ -497,7 +497,7 @@ static __always_inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp) * @cpu: cpu number (< nr_cpu_ids) * @cpumask: the cpumask pointer * - * Returns true if @cpu is set in @cpumask, else returns false + * Return: true if @cpu is set in @cpumask, else returns false */ static __always_inline bool cpumask_test_cpu(int cpu, const struct cpumask *cpumask) { @@ -509,9 +509,9 @@ static __always_inline bool cpumask_test_cpu(int cpu, const struct cpumask *cpum * @cpu: cpu number (< nr_cpu_ids) * @cpumask: the cpumask pointer * - * Returns true if @cpu is set in old bitmap of @cpumask, else returns false - * * test_and_set_bit wrapper for cpumasks. + * + * Return: true if @cpu is set in old bitmap of @cpumask, else returns false */ static __always_inline bool cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask) { @@ -523,9 +523,9 @@ static __always_inline bool cpumask_test_and_set_cpu(int cpu, struct cpumask *cp * @cpu: cpu number (< nr_cpu_ids) * @cpumask: the cpumask pointer * - * Returns true if @cpu is set in old bitmap of @cpumask, else returns false - * * test_and_clear_bit wrapper for cpumasks. + * + * Return: true if @cpu is set in old bitmap of @cpumask, else returns false */ static __always_inline bool cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask) { @@ -560,7 +560,7 @@ static inline void cpumask_clear(struct cpumask *dstp) * @src1p: the first input * @src2p: the second input * - * If *@dstp is empty, returns false, else returns true + * Return: false if *@dstp is empty, else returns true */ static inline bool cpumask_and(struct cpumask *dstp, const struct cpumask *src1p, @@ -603,7 +603,7 @@ static inline void cpumask_xor(struct cpumask *dstp, * @src1p: the first input * @src2p: the second input * - * If *@dstp is empty, returns false, else returns true + * Return: false if *@dstp is empty, else returns true */ static inline bool cpumask_andnot(struct cpumask *dstp, const struct cpumask *src1p, @@ -617,6 +617,8 @@ static inline bool cpumask_andnot(struct cpumask *dstp, * cpumask_equal - *src1p == *src2p * @src1p: the first input * @src2p: the second input + * + * Return: true if the cpumasks are equal, false if not */ static inline bool cpumask_equal(const struct cpumask *src1p, const struct cpumask *src2p) @@ -630,6 +632,9 @@ static inline bool cpumask_equal(const struct cpumask *src1p, * @src1p: the first input * @src2p: the second input * @src3p: the third input + * + * Return: true if first cpumask ORed with second cpumask == third cpumask, + * otherwise false */ static inline bool cpumask_or_equal(const struct cpumask *src1p, const struct cpumask *src2p, @@ -643,6 +648,9 @@ static inline bool cpumask_or_equal(const struct cpumask *src1p, * cpumask_intersects - (*src1p & *src2p) != 0 * @src1p: the first input * @src2p: the second input + * + * Return: true if first cpumask ANDed with second cpumask is non-empty, + * otherwise false */ static inline bool cpumask_intersects(const struct cpumask *src1p, const struct cpumask *src2p) @@ -656,7 +664,7 @@ static inline bool cpumask_intersects(const struct cpumask *src1p, * @src1p: the first input * @src2p: the second input * - * Returns true if *@src1p is a subset of *@src2p, else returns false + * Return: true if *@src1p is a subset of *@src2p, else returns false */ static inline bool cpumask_subset(const struct cpumask *src1p, const struct cpumask *src2p) @@ -668,6 +676,8 @@ static inline bool cpumask_subset(const struct cpumask *src1p, /** * cpumask_empty - *srcp == 0 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear. + * + * Return: true if srcp is empty (has no bits set), else false */ static inline bool cpumask_empty(const struct cpumask *srcp) { @@ -677,6 +687,8 @@ static inline bool cpumask_empty(const struct cpumask *srcp) /** * cpumask_full - *srcp == 0xFFFFFFFF... * @srcp: the cpumask to that all cpus < nr_cpu_ids are set. + * + * Return: true if srcp is full (has all bits set), else false */ static inline bool cpumask_full(const struct cpumask *srcp) { @@ -686,6 +698,8 @@ static inline bool cpumask_full(const struct cpumask *srcp) /** * cpumask_weight - Count of bits in *srcp * @srcp: the cpumask to count bits (< nr_cpu_ids) in. + * + * Return: count of bits set in *srcp */ static inline unsigned int cpumask_weight(const struct cpumask *srcp) { @@ -696,6 +710,8 @@ static inline unsigned int cpumask_weight(const struct cpumask *srcp) * cpumask_weight_and - Count of bits in (*srcp1 & *srcp2) * @srcp1: the cpumask to count bits (< nr_cpu_ids) in. * @srcp2: the cpumask to count bits (< nr_cpu_ids) in. + * + * Return: count of bits set in both *srcp1 and *srcp2 */ static inline unsigned int cpumask_weight_and(const struct cpumask *srcp1, const struct cpumask *srcp2) @@ -744,7 +760,7 @@ static inline void cpumask_copy(struct cpumask *dstp, * cpumask_any - pick a "random" cpu from *srcp * @srcp: the input cpumask * - * Returns >= nr_cpu_ids if no cpus set. + * Return: >= nr_cpu_ids if no cpus set. */ #define cpumask_any(srcp) cpumask_first(srcp) @@ -753,7 +769,7 @@ static inline void cpumask_copy(struct cpumask *dstp, * @mask1: the first input cpumask * @mask2: the second input cpumask * - * Returns >= nr_cpu_ids if no cpus set. + * Return: >= nr_cpu_ids if no cpus set. */ #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2)) @@ -769,7 +785,7 @@ static inline void cpumask_copy(struct cpumask *dstp, * @len: the length of the buffer * @dstp: the cpumask to set. * - * Returns -errno, or 0 for success. + * Return: -errno, or 0 for success. */ static inline int cpumask_parse_user(const char __user *buf, int len, struct cpumask *dstp) @@ -783,7 +799,7 @@ static inline int cpumask_parse_user(const char __user *buf, int len, * @len: the length of the buffer * @dstp: the cpumask to set. * - * Returns -errno, or 0 for success. + * Return: -errno, or 0 for success. */ static inline int cpumask_parselist_user(const char __user *buf, int len, struct cpumask *dstp) @@ -797,7 +813,7 @@ static inline int cpumask_parselist_user(const char __user *buf, int len, * @buf: the buffer to extract from * @dstp: the cpumask to set. * - * Returns -errno, or 0 for success. + * Return: -errno, or 0 for success. */ static inline int cpumask_parse(const char *buf, struct cpumask *dstp) { @@ -809,7 +825,7 @@ static inline int cpumask_parse(const char *buf, struct cpumask *dstp) * @buf: the buffer to extract from * @dstp: the cpumask to set. * - * Returns -errno, or 0 for success. + * Return: -errno, or 0 for success. */ static inline int cpulist_parse(const char *buf, struct cpumask *dstp) { @@ -817,7 +833,9 @@ static inline int cpulist_parse(const char *buf, struct cpumask *dstp) } /** - * cpumask_size - size to allocate for a 'struct cpumask' in bytes + * cpumask_size - calculate size to allocate for a 'struct cpumask' in bytes + * + * Return: size to allocate for a &struct cpumask in bytes */ static inline unsigned int cpumask_size(void) { @@ -831,7 +849,7 @@ static inline unsigned int cpumask_size(void) * little more difficult, we typedef cpumask_var_t to an array or a * pointer: doing &mask on an array is a noop, so it still works. * - * ie. + * i.e. * cpumask_var_t tmpmask; * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) * return -ENOMEM; @@ -887,6 +905,8 @@ bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) * a nop returning a constant 1 (in ). * * See alloc_cpumask_var_node. + * + * Return: %true if allocation succeeded, %false if not */ static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) @@ -1025,7 +1045,7 @@ set_cpu_dying(unsigned int cpu, bool dying) } /** - * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask * + * to_cpumask - convert a NR_CPUS bitmap to a struct cpumask * * @bitmap: the bitmap * * There are a few places where cpumask_var_t isn't appropriate and @@ -1068,6 +1088,8 @@ static inline const struct cpumask *get_cpu_mask(unsigned int cpu) * interface gives only a momentary snapshot and is not protected against * concurrent CPU hotplug operations unless invoked from a cpuhp_lock held * region. + * + * Return: momentary snapshot of the number of online CPUs */ static __always_inline unsigned int num_online_cpus(void) { @@ -1160,7 +1182,7 @@ static inline bool cpu_dying(unsigned int cpu) * @mask: the cpumask to copy * @buf: the buffer to copy into * - * Returns the length of the (null-terminated) @buf string, zero if + * Return: the length of the (null-terminated) @buf string, zero if * nothing is copied. */ static inline ssize_t @@ -1183,7 +1205,7 @@ cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) * cpumask; Typically used by bin_attribute to export cpumask bitmask * ABI. * - * Returns the length of how many bytes have been copied, excluding + * Return: the length of how many bytes have been copied, excluding * terminating '\0'. */ static inline ssize_t @@ -1204,6 +1226,9 @@ cpumap_print_bitmask_to_buf(char *buf, const struct cpumask *mask, * * Everything is same with the above cpumap_print_bitmask_to_buf() * except the print format. + * + * Return: the length of how many bytes have been copied, excluding + * terminating '\0'. */ static inline ssize_t cpumap_print_list_to_buf(char *buf, const struct cpumask *mask, diff --git a/lib/cpumask.c b/lib/cpumask.c index a7fd02b5ae26..19277c6d551f 100644 --- a/lib/cpumask.c +++ b/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 ) - * Returns TRUE if memory allocation succeeded, FALSE otherwise. + * a nop returning a constant 1 (in ). + * + * 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, @@ -165,7 +166,7 @@ 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) @@ -184,6 +185,12 @@ 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; From 8ed13a762ca0661e4df16ce5eba929e73f4bd8f6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jonathan=20Neusch=C3=A4fer?= Date: Mon, 14 Aug 2023 19:37:08 +0200 Subject: [PATCH 02/13] bitmap: Fix a typo ("identify map") MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit A map in which each element is mapped to itself is called an "identity map". Signed-off-by: Jonathan Neuschäfer Reviewed-by: Andy Shevchenko Signed-off-by: Yury Norov --- lib/bitmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index ddb31015e38a..24284caadbcc 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -988,7 +988,7 @@ static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigne * to @dst. * * The positions of unset bits in @old are mapped to themselves - * (the identify map). + * (the identity map). * * Apply the above specified mapping to @src, placing the result in * @dst, clearing any bits previously set in @dst. @@ -1037,7 +1037,7 @@ EXPORT_SYMBOL(bitmap_remap); * the position of the m-th set bit in @new, where m == n % w. * * The positions of unset bits in @old are mapped to themselves - * (the identify map). + * (the identity map). * * Apply the above specified mapping to bit position @oldbit, returning * the new bit position. From 7733aa893847f021c674d0d30b723d892109369d Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Thu, 17 Aug 2023 19:20:54 +0300 Subject: [PATCH 03/13] bitmap: Remove dead code, i.e. bitmap_copy_le() Besides the fact it's not used anywhere it should be implemented differently, i.e. via helpers from linux/byteorder/generic.h. Yet the helpers themselves need to be introduced first. Also note, the function lacks of the test cases, they must be provided. Hence, drop the current dead code for good. Signed-off-by: Andy Shevchenko Signed-off-by: Yury Norov --- include/linux/bitmap.h | 5 ----- lib/bitmap.c | 23 ----------------------- 2 files changed, 28 deletions(-) diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 03644237e1ef..1516ff979315 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -220,11 +220,6 @@ 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); diff --git a/lib/bitmap.c b/lib/bitmap.c index 24284caadbcc..935e0f96e785 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -1360,29 +1360,6 @@ int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) } EXPORT_SYMBOL(bitmap_allocate_region); -/** - * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. - * @dst: destination buffer - * @src: bitmap to copy - * @nbits: number of bits in the bitmap - * - * Require nbits % BITS_PER_LONG == 0. - */ -#ifdef __BIG_ENDIAN -void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) -{ - unsigned int i; - - for (i = 0; i < nbits/BITS_PER_LONG; i++) { - if (BITS_PER_LONG == 64) - dst[i] = cpu_to_le64(src[i]); - else - dst[i] = cpu_to_le32(src[i]); - } -} -EXPORT_SYMBOL(bitmap_copy_le); -#endif - unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) { return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), From aae06fc1b5a2e4b52f8504a1f12f9b8b98e80641 Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sat, 7 Oct 2023 16:35:10 -0700 Subject: [PATCH 04/13] lib/bitmap: split-out string-related operations to a separate files lib/bitmap.c and corresponding include/linux/bitmap.h are intended to hold functions related to operations on bitmaps, like bitmap_shift or bitmap_set. Historically, some string-related operations like bitmap_parse are also reside in lib/bitmap.c. Now that the subsystem evolves, string-related bitmap operations became a significant part of the file. Because they are quite different from the other bitmap functions by nature, it's worth to split them to a separate source/header files. CC: Andrew Morton CC: Andy Shevchenko CC: Rasmus Villemoes Signed-off-by: Yury Norov --- MAINTAINERS | 2 + include/linux/bitmap-str.h | 16 ++ include/linux/bitmap.h | 18 +- lib/Makefile | 2 +- lib/bitmap-str.c | 510 ++++++++++++++++++++++++++++++++++++ lib/bitmap.c | 512 ------------------------------------- 6 files changed, 530 insertions(+), 530 deletions(-) create mode 100644 include/linux/bitmap-str.h create mode 100644 lib/bitmap-str.c diff --git a/MAINTAINERS b/MAINTAINERS index 6c4cce45a09d..561def8239f9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3506,12 +3506,14 @@ R: Andy Shevchenko R: Rasmus Villemoes 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 diff --git a/include/linux/bitmap-str.h b/include/linux/bitmap-str.h new file mode 100644 index 000000000000..17caeca94cab --- /dev/null +++ b/include/linux/bitmap-str.h @@ -0,0 +1,16 @@ +/* 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 */ diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 1516ff979315..1cca950a54ae 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -10,6 +10,7 @@ #include #include #include +#include struct device; @@ -200,14 +201,6 @@ 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, @@ -220,15 +213,6 @@ 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); -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))) diff --git a/lib/Makefile b/lib/Makefile index 740109b6e2c8..9e8f9f6dd3b2 100644 --- a/lib/Makefile +++ b/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 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 diff --git a/lib/bitmap-str.c b/lib/bitmap-str.c new file mode 100644 index 000000000000..be745209507a --- /dev/null +++ b/lib/bitmap-str.c @@ -0,0 +1,510 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "kstrtox.h" + +/** + * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap + * + * @ubuf: pointer to user buffer containing string. + * @ulen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0. + * @maskp: pointer to bitmap array that will contain result. + * @nmaskbits: size of bitmap, in bits. + */ +int bitmap_parse_user(const char __user *ubuf, + unsigned int ulen, unsigned long *maskp, + int nmaskbits) +{ + char *buf; + int ret; + + buf = memdup_user_nul(ubuf, ulen); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits); + + kfree(buf); + return ret; +} +EXPORT_SYMBOL(bitmap_parse_user); + +/** + * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string + * @list: indicates whether the bitmap must be list + * @buf: page aligned buffer into which string is placed + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * + * Output format is a comma-separated list of decimal numbers and + * ranges if list is specified or hex digits grouped into comma-separated + * sets of 8 digits/set. Returns the number of characters written to buf. + * + * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned + * area and that sufficient storage remains at @buf to accommodate the + * bitmap_print_to_pagebuf() output. Returns the number of characters + * actually printed to @buf, excluding terminating '\0'. + */ +int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, + int nmaskbits) +{ + ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); + + return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : + scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); +} +EXPORT_SYMBOL(bitmap_print_to_pagebuf); + +/** + * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string + * @list: indicates whether the bitmap must be list + * true: print in decimal list format + * false: print in hexadecimal bitmask format + * @buf: buffer into which string is placed + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * @off: in the string from which we are copying, We copy to @buf + * @count: the maximum number of bytes to print + */ +static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count) +{ + const char *fmt = list ? "%*pbl\n" : "%*pb\n"; + ssize_t size; + void *data; + + data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp); + if (!data) + return -ENOMEM; + + size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1); + kfree(data); + + return size; +} + +/** + * bitmap_print_bitmask_to_buf - convert bitmap to hex bitmask format ASCII string + * @buf: buffer into which string is placed + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * @off: in the string from which we are copying, We copy to @buf + * @count: the maximum number of bytes to print + * + * The bitmap_print_to_pagebuf() is used indirectly via its cpumap wrapper + * cpumap_print_to_pagebuf() or directly by drivers to export hexadecimal + * bitmask and decimal list to userspace by sysfs ABI. + * Drivers might be using a normal attribute for this kind of ABIs. A + * normal attribute typically has show entry as below:: + * + * static ssize_t example_attribute_show(struct device *dev, + * struct device_attribute *attr, char *buf) + * { + * ... + * return bitmap_print_to_pagebuf(true, buf, &mask, nr_trig_max); + * } + * + * show entry of attribute has no offset and count parameters and this + * means the file is limited to one page only. + * bitmap_print_to_pagebuf() API works terribly well for this kind of + * normal attribute with buf parameter and without offset, count:: + * + * bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, + * int nmaskbits) + * { + * } + * + * The problem is once we have a large bitmap, we have a chance to get a + * bitmask or list more than one page. Especially for list, it could be + * as complex as 0,3,5,7,9,... We have no simple way to know it exact size. + * It turns out bin_attribute is a way to break this limit. bin_attribute + * has show entry as below:: + * + * static ssize_t + * example_bin_attribute_show(struct file *filp, struct kobject *kobj, + * struct bin_attribute *attr, char *buf, + * loff_t offset, size_t count) + * { + * ... + * } + * + * With the new offset and count parameters, this makes sysfs ABI be able + * to support file size more than one page. For example, offset could be + * >= 4096. + * bitmap_print_bitmask_to_buf(), bitmap_print_list_to_buf() wit their + * cpumap wrapper cpumap_print_bitmask_to_buf(), cpumap_print_list_to_buf() + * make those drivers be able to support large bitmask and list after they + * move to use bin_attribute. In result, we have to pass the corresponding + * parameters such as off, count from bin_attribute show entry to this API. + * + * The role of cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf() + * is similar with cpumap_print_to_pagebuf(), the difference is that + * bitmap_print_to_pagebuf() mainly serves sysfs attribute with the assumption + * the destination buffer is exactly one page and won't be more than one page. + * cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf(), on the other + * hand, mainly serves bin_attribute which doesn't work with exact one page, + * and it can break the size limit of converted decimal list and hexadecimal + * bitmask. + * + * WARNING! + * + * This function is not a replacement for sprintf() or bitmap_print_to_pagebuf(). + * It is intended to workaround sysfs limitations discussed above and should be + * used carefully in general case for the following reasons: + * + * - Time complexity is O(nbits^2/count), comparing to O(nbits) for snprintf(). + * - Memory complexity is O(nbits), comparing to O(1) for snprintf(). + * - @off and @count are NOT offset and number of bits to print. + * - If printing part of bitmap as list, the resulting string is not a correct + * list representation of bitmap. Particularly, some bits within or out of + * related interval may be erroneously set or unset. The format of the string + * may be broken, so bitmap_parselist-like parser may fail parsing it. + * - If printing the whole bitmap as list by parts, user must ensure the order + * of calls of the function such that the offset is incremented linearly. + * - If printing the whole bitmap as list by parts, user must keep bitmap + * unchanged between the very first and very last call. Otherwise concatenated + * result may be incorrect, and format may be broken. + * + * Returns the number of characters actually printed to @buf + */ +int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count) +{ + return bitmap_print_to_buf(false, buf, maskp, nmaskbits, off, count); +} +EXPORT_SYMBOL(bitmap_print_bitmask_to_buf); + +/** + * bitmap_print_list_to_buf - convert bitmap to decimal list format ASCII string + * @buf: buffer into which string is placed + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * @off: in the string from which we are copying, We copy to @buf + * @count: the maximum number of bytes to print + * + * Everything is same with the above bitmap_print_bitmask_to_buf() except + * the print format. + */ +int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, + int nmaskbits, loff_t off, size_t count) +{ + return bitmap_print_to_buf(true, buf, maskp, nmaskbits, off, count); +} +EXPORT_SYMBOL(bitmap_print_list_to_buf); + +/* + * Region 9-38:4/10 describes the following bitmap structure: + * 0 9 12 18 38 N + * .........****......****......****.................. + * ^ ^ ^ ^ ^ + * start off group_len end nbits + */ +struct region { + unsigned int start; + unsigned int off; + unsigned int group_len; + unsigned int end; + unsigned int nbits; +}; + +static void bitmap_set_region(const struct region *r, unsigned long *bitmap) +{ + unsigned int start; + + for (start = r->start; start <= r->end; start += r->group_len) + bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); +} + +static int bitmap_check_region(const struct region *r) +{ + if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) + return -EINVAL; + + if (r->end >= r->nbits) + return -ERANGE; + + return 0; +} + +static const char *bitmap_getnum(const char *str, unsigned int *num, + unsigned int lastbit) +{ + unsigned long long n; + unsigned int len; + + if (str[0] == 'N') { + *num = lastbit; + return str + 1; + } + + len = _parse_integer(str, 10, &n); + if (!len) + return ERR_PTR(-EINVAL); + if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) + return ERR_PTR(-EOVERFLOW); + + *num = n; + return str + len; +} + +static inline bool end_of_str(char c) +{ + return c == '\0' || c == '\n'; +} + +static inline bool __end_of_region(char c) +{ + return isspace(c) || c == ','; +} + +static inline bool end_of_region(char c) +{ + return __end_of_region(c) || end_of_str(c); +} + +/* + * The format allows commas and whitespaces at the beginning + * of the region. + */ +static const char *bitmap_find_region(const char *str) +{ + while (__end_of_region(*str)) + str++; + + return end_of_str(*str) ? NULL : str; +} + +static const char *bitmap_find_region_reverse(const char *start, const char *end) +{ + while (start <= end && __end_of_region(*end)) + end--; + + return end; +} + +static const char *bitmap_parse_region(const char *str, struct region *r) +{ + unsigned int lastbit = r->nbits - 1; + + if (!strncasecmp(str, "all", 3)) { + r->start = 0; + r->end = lastbit; + str += 3; + + goto check_pattern; + } + + str = bitmap_getnum(str, &r->start, lastbit); + if (IS_ERR(str)) + return str; + + if (end_of_region(*str)) + goto no_end; + + if (*str != '-') + return ERR_PTR(-EINVAL); + + str = bitmap_getnum(str + 1, &r->end, lastbit); + if (IS_ERR(str)) + return str; + +check_pattern: + if (end_of_region(*str)) + goto no_pattern; + + if (*str != ':') + return ERR_PTR(-EINVAL); + + str = bitmap_getnum(str + 1, &r->off, lastbit); + if (IS_ERR(str)) + return str; + + if (*str != '/') + return ERR_PTR(-EINVAL); + + return bitmap_getnum(str + 1, &r->group_len, lastbit); + +no_end: + r->end = r->start; +no_pattern: + r->off = r->end + 1; + r->group_len = r->end + 1; + + return end_of_str(*str) ? NULL : str; +} + +/** + * bitmap_parselist - convert list format ASCII string to bitmap + * @buf: read user string from this buffer; must be terminated + * with a \0 or \n. + * @maskp: write resulting mask here + * @nmaskbits: number of bits in mask to be written + * + * Input format is a comma-separated list of decimal numbers and + * ranges. Consecutively set bits are shown as two hyphen-separated + * decimal numbers, the smallest and largest bit numbers set in + * the range. + * Optionally each range can be postfixed to denote that only parts of it + * should be set. The range will divided to groups of specific size. + * From each group will be used only defined amount of bits. + * Syntax: range:used_size/group_size + * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 + * The value 'N' can be used as a dynamically substituted token for the + * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is + * dynamic, so if system changes cause the bitmap width to change, such + * as more cores in a CPU list, then any ranges using N will also change. + * + * Returns: 0 on success, -errno on invalid input strings. Error values: + * + * - ``-EINVAL``: wrong region format + * - ``-EINVAL``: invalid character in string + * - ``-ERANGE``: bit number specified too large for mask + * - ``-EOVERFLOW``: integer overflow in the input parameters + */ +int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) +{ + struct region r; + long ret; + + r.nbits = nmaskbits; + bitmap_zero(maskp, r.nbits); + + while (buf) { + buf = bitmap_find_region(buf); + if (buf == NULL) + return 0; + + buf = bitmap_parse_region(buf, &r); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + ret = bitmap_check_region(&r); + if (ret) + return ret; + + bitmap_set_region(&r, maskp); + } + + return 0; +} +EXPORT_SYMBOL(bitmap_parselist); + + +/** + * bitmap_parselist_user() - convert user buffer's list format ASCII + * string to bitmap + * + * @ubuf: pointer to user buffer containing string. + * @ulen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0. + * @maskp: pointer to bitmap array that will contain result. + * @nmaskbits: size of bitmap, in bits. + * + * Wrapper for bitmap_parselist(), providing it with user buffer. + */ +int bitmap_parselist_user(const char __user *ubuf, + unsigned int ulen, unsigned long *maskp, + int nmaskbits) +{ + char *buf; + int ret; + + buf = memdup_user_nul(ubuf, ulen); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + ret = bitmap_parselist(buf, maskp, nmaskbits); + + kfree(buf); + return ret; +} +EXPORT_SYMBOL(bitmap_parselist_user); + +static const char *bitmap_get_x32_reverse(const char *start, + const char *end, u32 *num) +{ + u32 ret = 0; + int c, i; + + for (i = 0; i < 32; i += 4) { + c = hex_to_bin(*end--); + if (c < 0) + return ERR_PTR(-EINVAL); + + ret |= c << i; + + if (start > end || __end_of_region(*end)) + goto out; + } + + if (hex_to_bin(*end--) >= 0) + return ERR_PTR(-EOVERFLOW); +out: + *num = ret; + return end; +} + +/** + * bitmap_parse - convert an ASCII hex string into a bitmap. + * @start: pointer to buffer containing string. + * @buflen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0 or \n. In that case, + * UINT_MAX may be provided instead of string length. + * @maskp: pointer to bitmap array that will contain result. + * @nmaskbits: size of bitmap, in bits. + * + * Commas group hex digits into chunks. Each chunk defines exactly 32 + * bits of the resultant bitmask. No chunk may specify a value larger + * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value + * then leading 0-bits are prepended. %-EINVAL is returned for illegal + * characters. Grouping such as "1,,5", ",44", "," or "" is allowed. + * Leading, embedded and trailing whitespace accepted. + */ +int bitmap_parse(const char *start, unsigned int buflen, + unsigned long *maskp, int nmaskbits) +{ + const char *end = strnchrnul(start, buflen, '\n') - 1; + int chunks = BITS_TO_U32(nmaskbits); + u32 *bitmap = (u32 *)maskp; + int unset_bit; + int chunk; + + for (chunk = 0; ; chunk++) { + end = bitmap_find_region_reverse(start, end); + if (start > end) + break; + + if (!chunks--) + return -EOVERFLOW; + +#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) + end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]); +#else + end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]); +#endif + if (IS_ERR(end)) + return PTR_ERR(end); + } + + unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32; + if (unset_bit < nmaskbits) { + bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit); + return 0; + } + + if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit) + return -EOVERFLOW; + + return 0; +} +EXPORT_SYMBOL(bitmap_parse); diff --git a/lib/bitmap.c b/lib/bitmap.c index 935e0f96e785..abc5579768e9 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -6,21 +6,11 @@ #include #include -#include #include #include #include #include -#include -#include #include -#include -#include -#include - -#include - -#include "kstrtox.h" /** * DOC: bitmap introduction @@ -440,508 +430,6 @@ again: } EXPORT_SYMBOL(bitmap_find_next_zero_area_off); -/* - * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, - * second version by Paul Jackson, third by Joe Korty. - */ - -/** - * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap - * - * @ubuf: pointer to user buffer containing string. - * @ulen: buffer size in bytes. If string is smaller than this - * then it must be terminated with a \0. - * @maskp: pointer to bitmap array that will contain result. - * @nmaskbits: size of bitmap, in bits. - */ -int bitmap_parse_user(const char __user *ubuf, - unsigned int ulen, unsigned long *maskp, - int nmaskbits) -{ - char *buf; - int ret; - - buf = memdup_user_nul(ubuf, ulen); - if (IS_ERR(buf)) - return PTR_ERR(buf); - - ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits); - - kfree(buf); - return ret; -} -EXPORT_SYMBOL(bitmap_parse_user); - -/** - * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string - * @list: indicates whether the bitmap must be list - * @buf: page aligned buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * - * Output format is a comma-separated list of decimal numbers and - * ranges if list is specified or hex digits grouped into comma-separated - * sets of 8 digits/set. Returns the number of characters written to buf. - * - * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned - * area and that sufficient storage remains at @buf to accommodate the - * bitmap_print_to_pagebuf() output. Returns the number of characters - * actually printed to @buf, excluding terminating '\0'. - */ -int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, - int nmaskbits) -{ - ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); - - return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : - scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); -} -EXPORT_SYMBOL(bitmap_print_to_pagebuf); - -/** - * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string - * @list: indicates whether the bitmap must be list - * true: print in decimal list format - * false: print in hexadecimal bitmask format - * @buf: buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * @off: in the string from which we are copying, We copy to @buf - * @count: the maximum number of bytes to print - */ -static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count) -{ - const char *fmt = list ? "%*pbl\n" : "%*pb\n"; - ssize_t size; - void *data; - - data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp); - if (!data) - return -ENOMEM; - - size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1); - kfree(data); - - return size; -} - -/** - * bitmap_print_bitmask_to_buf - convert bitmap to hex bitmask format ASCII string - * @buf: buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * @off: in the string from which we are copying, We copy to @buf - * @count: the maximum number of bytes to print - * - * The bitmap_print_to_pagebuf() is used indirectly via its cpumap wrapper - * cpumap_print_to_pagebuf() or directly by drivers to export hexadecimal - * bitmask and decimal list to userspace by sysfs ABI. - * Drivers might be using a normal attribute for this kind of ABIs. A - * normal attribute typically has show entry as below:: - * - * static ssize_t example_attribute_show(struct device *dev, - * struct device_attribute *attr, char *buf) - * { - * ... - * return bitmap_print_to_pagebuf(true, buf, &mask, nr_trig_max); - * } - * - * show entry of attribute has no offset and count parameters and this - * means the file is limited to one page only. - * bitmap_print_to_pagebuf() API works terribly well for this kind of - * normal attribute with buf parameter and without offset, count:: - * - * bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, - * int nmaskbits) - * { - * } - * - * The problem is once we have a large bitmap, we have a chance to get a - * bitmask or list more than one page. Especially for list, it could be - * as complex as 0,3,5,7,9,... We have no simple way to know it exact size. - * It turns out bin_attribute is a way to break this limit. bin_attribute - * has show entry as below:: - * - * static ssize_t - * example_bin_attribute_show(struct file *filp, struct kobject *kobj, - * struct bin_attribute *attr, char *buf, - * loff_t offset, size_t count) - * { - * ... - * } - * - * With the new offset and count parameters, this makes sysfs ABI be able - * to support file size more than one page. For example, offset could be - * >= 4096. - * bitmap_print_bitmask_to_buf(), bitmap_print_list_to_buf() wit their - * cpumap wrapper cpumap_print_bitmask_to_buf(), cpumap_print_list_to_buf() - * make those drivers be able to support large bitmask and list after they - * move to use bin_attribute. In result, we have to pass the corresponding - * parameters such as off, count from bin_attribute show entry to this API. - * - * The role of cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf() - * is similar with cpumap_print_to_pagebuf(), the difference is that - * bitmap_print_to_pagebuf() mainly serves sysfs attribute with the assumption - * the destination buffer is exactly one page and won't be more than one page. - * cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf(), on the other - * hand, mainly serves bin_attribute which doesn't work with exact one page, - * and it can break the size limit of converted decimal list and hexadecimal - * bitmask. - * - * WARNING! - * - * This function is not a replacement for sprintf() or bitmap_print_to_pagebuf(). - * It is intended to workaround sysfs limitations discussed above and should be - * used carefully in general case for the following reasons: - * - * - Time complexity is O(nbits^2/count), comparing to O(nbits) for snprintf(). - * - Memory complexity is O(nbits), comparing to O(1) for snprintf(). - * - @off and @count are NOT offset and number of bits to print. - * - If printing part of bitmap as list, the resulting string is not a correct - * list representation of bitmap. Particularly, some bits within or out of - * related interval may be erroneously set or unset. The format of the string - * may be broken, so bitmap_parselist-like parser may fail parsing it. - * - If printing the whole bitmap as list by parts, user must ensure the order - * of calls of the function such that the offset is incremented linearly. - * - If printing the whole bitmap as list by parts, user must keep bitmap - * unchanged between the very first and very last call. Otherwise concatenated - * result may be incorrect, and format may be broken. - * - * Returns the number of characters actually printed to @buf - */ -int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count) -{ - return bitmap_print_to_buf(false, buf, maskp, nmaskbits, off, count); -} -EXPORT_SYMBOL(bitmap_print_bitmask_to_buf); - -/** - * bitmap_print_list_to_buf - convert bitmap to decimal list format ASCII string - * @buf: buffer into which string is placed - * @maskp: pointer to bitmap to convert - * @nmaskbits: size of bitmap, in bits - * @off: in the string from which we are copying, We copy to @buf - * @count: the maximum number of bytes to print - * - * Everything is same with the above bitmap_print_bitmask_to_buf() except - * the print format. - */ -int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, - int nmaskbits, loff_t off, size_t count) -{ - return bitmap_print_to_buf(true, buf, maskp, nmaskbits, off, count); -} -EXPORT_SYMBOL(bitmap_print_list_to_buf); - -/* - * Region 9-38:4/10 describes the following bitmap structure: - * 0 9 12 18 38 N - * .........****......****......****.................. - * ^ ^ ^ ^ ^ - * start off group_len end nbits - */ -struct region { - unsigned int start; - unsigned int off; - unsigned int group_len; - unsigned int end; - unsigned int nbits; -}; - -static void bitmap_set_region(const struct region *r, unsigned long *bitmap) -{ - unsigned int start; - - for (start = r->start; start <= r->end; start += r->group_len) - bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); -} - -static int bitmap_check_region(const struct region *r) -{ - if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) - return -EINVAL; - - if (r->end >= r->nbits) - return -ERANGE; - - return 0; -} - -static const char *bitmap_getnum(const char *str, unsigned int *num, - unsigned int lastbit) -{ - unsigned long long n; - unsigned int len; - - if (str[0] == 'N') { - *num = lastbit; - return str + 1; - } - - len = _parse_integer(str, 10, &n); - if (!len) - return ERR_PTR(-EINVAL); - if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) - return ERR_PTR(-EOVERFLOW); - - *num = n; - return str + len; -} - -static inline bool end_of_str(char c) -{ - return c == '\0' || c == '\n'; -} - -static inline bool __end_of_region(char c) -{ - return isspace(c) || c == ','; -} - -static inline bool end_of_region(char c) -{ - return __end_of_region(c) || end_of_str(c); -} - -/* - * The format allows commas and whitespaces at the beginning - * of the region. - */ -static const char *bitmap_find_region(const char *str) -{ - while (__end_of_region(*str)) - str++; - - return end_of_str(*str) ? NULL : str; -} - -static const char *bitmap_find_region_reverse(const char *start, const char *end) -{ - while (start <= end && __end_of_region(*end)) - end--; - - return end; -} - -static const char *bitmap_parse_region(const char *str, struct region *r) -{ - unsigned int lastbit = r->nbits - 1; - - if (!strncasecmp(str, "all", 3)) { - r->start = 0; - r->end = lastbit; - str += 3; - - goto check_pattern; - } - - str = bitmap_getnum(str, &r->start, lastbit); - if (IS_ERR(str)) - return str; - - if (end_of_region(*str)) - goto no_end; - - if (*str != '-') - return ERR_PTR(-EINVAL); - - str = bitmap_getnum(str + 1, &r->end, lastbit); - if (IS_ERR(str)) - return str; - -check_pattern: - if (end_of_region(*str)) - goto no_pattern; - - if (*str != ':') - return ERR_PTR(-EINVAL); - - str = bitmap_getnum(str + 1, &r->off, lastbit); - if (IS_ERR(str)) - return str; - - if (*str != '/') - return ERR_PTR(-EINVAL); - - return bitmap_getnum(str + 1, &r->group_len, lastbit); - -no_end: - r->end = r->start; -no_pattern: - r->off = r->end + 1; - r->group_len = r->end + 1; - - return end_of_str(*str) ? NULL : str; -} - -/** - * bitmap_parselist - convert list format ASCII string to bitmap - * @buf: read user string from this buffer; must be terminated - * with a \0 or \n. - * @maskp: write resulting mask here - * @nmaskbits: number of bits in mask to be written - * - * Input format is a comma-separated list of decimal numbers and - * ranges. Consecutively set bits are shown as two hyphen-separated - * decimal numbers, the smallest and largest bit numbers set in - * the range. - * Optionally each range can be postfixed to denote that only parts of it - * should be set. The range will divided to groups of specific size. - * From each group will be used only defined amount of bits. - * Syntax: range:used_size/group_size - * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 - * The value 'N' can be used as a dynamically substituted token for the - * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is - * dynamic, so if system changes cause the bitmap width to change, such - * as more cores in a CPU list, then any ranges using N will also change. - * - * Returns: 0 on success, -errno on invalid input strings. Error values: - * - * - ``-EINVAL``: wrong region format - * - ``-EINVAL``: invalid character in string - * - ``-ERANGE``: bit number specified too large for mask - * - ``-EOVERFLOW``: integer overflow in the input parameters - */ -int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) -{ - struct region r; - long ret; - - r.nbits = nmaskbits; - bitmap_zero(maskp, r.nbits); - - while (buf) { - buf = bitmap_find_region(buf); - if (buf == NULL) - return 0; - - buf = bitmap_parse_region(buf, &r); - if (IS_ERR(buf)) - return PTR_ERR(buf); - - ret = bitmap_check_region(&r); - if (ret) - return ret; - - bitmap_set_region(&r, maskp); - } - - return 0; -} -EXPORT_SYMBOL(bitmap_parselist); - - -/** - * bitmap_parselist_user() - convert user buffer's list format ASCII - * string to bitmap - * - * @ubuf: pointer to user buffer containing string. - * @ulen: buffer size in bytes. If string is smaller than this - * then it must be terminated with a \0. - * @maskp: pointer to bitmap array that will contain result. - * @nmaskbits: size of bitmap, in bits. - * - * Wrapper for bitmap_parselist(), providing it with user buffer. - */ -int bitmap_parselist_user(const char __user *ubuf, - unsigned int ulen, unsigned long *maskp, - int nmaskbits) -{ - char *buf; - int ret; - - buf = memdup_user_nul(ubuf, ulen); - if (IS_ERR(buf)) - return PTR_ERR(buf); - - ret = bitmap_parselist(buf, maskp, nmaskbits); - - kfree(buf); - return ret; -} -EXPORT_SYMBOL(bitmap_parselist_user); - -static const char *bitmap_get_x32_reverse(const char *start, - const char *end, u32 *num) -{ - u32 ret = 0; - int c, i; - - for (i = 0; i < 32; i += 4) { - c = hex_to_bin(*end--); - if (c < 0) - return ERR_PTR(-EINVAL); - - ret |= c << i; - - if (start > end || __end_of_region(*end)) - goto out; - } - - if (hex_to_bin(*end--) >= 0) - return ERR_PTR(-EOVERFLOW); -out: - *num = ret; - return end; -} - -/** - * bitmap_parse - convert an ASCII hex string into a bitmap. - * @start: pointer to buffer containing string. - * @buflen: buffer size in bytes. If string is smaller than this - * then it must be terminated with a \0 or \n. In that case, - * UINT_MAX may be provided instead of string length. - * @maskp: pointer to bitmap array that will contain result. - * @nmaskbits: size of bitmap, in bits. - * - * Commas group hex digits into chunks. Each chunk defines exactly 32 - * bits of the resultant bitmask. No chunk may specify a value larger - * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value - * then leading 0-bits are prepended. %-EINVAL is returned for illegal - * characters. Grouping such as "1,,5", ",44", "," or "" is allowed. - * Leading, embedded and trailing whitespace accepted. - */ -int bitmap_parse(const char *start, unsigned int buflen, - unsigned long *maskp, int nmaskbits) -{ - const char *end = strnchrnul(start, buflen, '\n') - 1; - int chunks = BITS_TO_U32(nmaskbits); - u32 *bitmap = (u32 *)maskp; - int unset_bit; - int chunk; - - for (chunk = 0; ; chunk++) { - end = bitmap_find_region_reverse(start, end); - if (start > end) - break; - - if (!chunks--) - return -EOVERFLOW; - -#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) - end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]); -#else - end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]); -#endif - if (IS_ERR(end)) - return PTR_ERR(end); - } - - unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32; - if (unset_bit < nmaskbits) { - bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit); - return 0; - } - - if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit) - return -EOVERFLOW; - - return 0; -} -EXPORT_SYMBOL(bitmap_parse); - /** * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap * @buf: pointer to a bitmap From 82bf9bdfbce9cfa73ccd86642542159119e0419f Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sun, 24 Sep 2023 19:38:10 -0700 Subject: [PATCH 05/13] bitmap: align __reg_op() wrappers with modern coding style Fix comments so that scripts/kernel-doc doesn't warn, and fix for-loop stype in bitmap_find_free_region(). CC: Rasmus Villemoes Suggested-by: Andy Shevchenko Reviewed-by: Andy Shevchenko Signed-off-by: Yury Norov --- lib/bitmap.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index abc5579768e9..f77243ba5e1c 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -722,8 +722,8 @@ void bitmap_fold(unsigned long *dst, const unsigned long *orig, * some size '1 << order' (a power of two), aligned to that same * '1 << order' power of two. * - * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). - * Returns 0 in all other cases and reg_ops. + * Return: 1 if REG_OP_ISFREE succeeds (region is all zero bits). + * 0 in all other cases and reg_ops. */ enum { @@ -795,14 +795,14 @@ done: * a power (@order) of two, aligned to that power of two, which * makes the search algorithm much faster. * - * Return the bit offset in bitmap of the allocated region, + * Return: the bit offset in bitmap of the allocated region, * or -errno on failure. */ 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 + (1U << order)) <= bits; pos = end) { + for (pos = 0; (end = pos + BIT(order)) <= bits; pos = end) { if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) continue; __reg_op(bitmap, pos, order, REG_OP_ALLOC); @@ -820,8 +820,6 @@ EXPORT_SYMBOL(bitmap_find_free_region); * * This is the complement to __bitmap_find_free_region() and releases * the found region (by clearing it in the bitmap). - * - * No return value. */ void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) { @@ -837,7 +835,7 @@ EXPORT_SYMBOL(bitmap_release_region); * * Allocate (set bits in) a specified region of a bitmap. * - * Return 0 on success, or %-EBUSY if specified region wasn't + * Return: 0 on success, or %-EBUSY if specified region wasn't * free (not all bits were zero). */ int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) From 6d5d3a0c33e0b3cab91e2d229f94b51d80d91fe3 Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sun, 24 Sep 2023 19:38:11 -0700 Subject: [PATCH 06/13] bitmap: add test for bitmap_*_region() functions Test basic functionality of bitmap_{allocate,release,find_free}_region() functions. CC: Rasmus Villemoes Reviewed-by: Andy Shevchenko Signed-off-by: Yury Norov --- lib/test_bitmap.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c index f2ea9f30c7c5..65f22c2578b0 100644 --- a/lib/test_bitmap.c +++ b/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(); From b085f969ed3df1916b9d9029225f2472df33cc17 Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sun, 24 Sep 2023 19:38:12 -0700 Subject: [PATCH 07/13] bitmap: fix opencoded bitmap_allocate_region() bitmap_find_region() opencodes bitmap_allocate_region(). CC: Andy Shevchenko CC: Rasmus Villemoes Signed-off-by: Yury Norov --- lib/bitmap.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index f77243ba5e1c..a0b02974d898 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -803,10 +803,8 @@ 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 (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) - continue; - __reg_op(bitmap, pos, order, REG_OP_ALLOC); - return pos; + if (!bitmap_allocate_region(bitmap, pos, order)) + return pos; } return -ENOMEM; } From eae5acbd7572f2874cd2f04dd540870dca256826 Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sun, 24 Sep 2023 19:38:13 -0700 Subject: [PATCH 08/13] bitmap: replace _reg_op(REG_OP_ALLOC) with bitmap_set() _reg_op(REG_OP_ALLOC) duplicates bitmap_set(). CC: Andy Shevchenko CC: Rasmus Villemoes Signed-off-by: Yury Norov --- lib/bitmap.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index a0b02974d898..8ee7d4857179 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -838,9 +838,12 @@ EXPORT_SYMBOL(bitmap_release_region); */ int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) { + unsigned int len = BIT(order); + if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) return -EBUSY; - return __reg_op(bitmap, pos, order, REG_OP_ALLOC); + bitmap_set(bitmap, pos, len); + return 0; } EXPORT_SYMBOL(bitmap_allocate_region); From add00c76ee4dafbc35b170bea144358fd62daebb Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sun, 24 Sep 2023 19:38:14 -0700 Subject: [PATCH 09/13] bitmap: replace _reg_op(REG_OP_RELEASE) with bitmap_clear() _reg_op(REG_OP_RELEASE) duplicates bitmap_clear(). CC: Andy Shevchenko CC: Rasmus Villemoes Signed-off-by: Yury Norov --- lib/bitmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index 8ee7d4857179..babed4dcb467 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -821,7 +821,7 @@ EXPORT_SYMBOL(bitmap_find_free_region); */ void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) { - __reg_op(bitmap, pos, order, REG_OP_RELEASE); + bitmap_clear(bitmap, pos, BIT(order)); } EXPORT_SYMBOL(bitmap_release_region); From 9276819a68b52cf2577f77985041faf527cf477c Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sun, 24 Sep 2023 19:38:15 -0700 Subject: [PATCH 10/13] bitmap: replace _reg_op(REG_OP_ISFREE) with find_next_bit() _reg_op(REG_OP_ISFREE) can be trivially replaced with find_next_bit(). Doing that opens room for potential small_const_nbits() optimization. CC: Andy Shevchenko CC: Rasmus Villemoes Signed-off-by: Yury Norov --- lib/bitmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index babed4dcb467..e4d761a69fe8 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -840,7 +840,7 @@ int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) { unsigned int len = BIT(order); - if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) + if (find_next_bit(bitmap, pos + len, pos) < pos + len) return -EBUSY; bitmap_set(bitmap, pos, len); return 0; From 1d4836527d4168d648010909637fb6cfe45d3fac Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sun, 24 Sep 2023 19:38:16 -0700 Subject: [PATCH 11/13] bitmap: drop _reg_op() function Now that all _reg_op() users are switched to alternative functions, _reg_op() machinery is not needed anymore. CC: Andy Shevchenko CC: Rasmus Villemoes Signed-off-by: Yury Norov --- lib/bitmap.c | 76 ---------------------------------------------------- 1 file changed, 76 deletions(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index e4d761a69fe8..66da8c33fb1b 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -708,82 +708,6 @@ void bitmap_fold(unsigned long *dst, const unsigned long *orig, } #endif /* CONFIG_NUMA */ -/* - * Common code for bitmap_*_region() routines. - * bitmap: array of unsigned longs corresponding to the bitmap - * pos: the beginning of the region - * order: region size (log base 2 of number of bits) - * reg_op: operation(s) to perform on that region of bitmap - * - * Can set, verify and/or release a region of bits in a bitmap, - * depending on which combination of REG_OP_* flag bits is set. - * - * A region of a bitmap is a sequence of bits in the bitmap, of - * some size '1 << order' (a power of two), aligned to that same - * '1 << order' power of two. - * - * Return: 1 if REG_OP_ISFREE succeeds (region is all zero bits). - * 0 in all other cases and reg_ops. - */ - -enum { - REG_OP_ISFREE, /* true if region is all zero bits */ - REG_OP_ALLOC, /* set all bits in region */ - REG_OP_RELEASE, /* clear all bits in region */ -}; - -static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) -{ - int nbits_reg; /* number of bits in region */ - int index; /* index first long of region in bitmap */ - int offset; /* bit offset region in bitmap[index] */ - int nlongs_reg; /* num longs spanned by region in bitmap */ - int nbitsinlong; /* num bits of region in each spanned long */ - unsigned long mask; /* bitmask for one long of region */ - int i; /* scans bitmap by longs */ - int ret = 0; /* return value */ - - /* - * Either nlongs_reg == 1 (for small orders that fit in one long) - * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) - */ - nbits_reg = 1 << order; - index = pos / BITS_PER_LONG; - offset = pos - (index * BITS_PER_LONG); - nlongs_reg = BITS_TO_LONGS(nbits_reg); - nbitsinlong = min(nbits_reg, BITS_PER_LONG); - - /* - * Can't do "mask = (1UL << nbitsinlong) - 1", as that - * overflows if nbitsinlong == BITS_PER_LONG. - */ - mask = (1UL << (nbitsinlong - 1)); - mask += mask - 1; - mask <<= offset; - - switch (reg_op) { - case REG_OP_ISFREE: - for (i = 0; i < nlongs_reg; i++) { - if (bitmap[index + i] & mask) - goto done; - } - ret = 1; /* all bits in region free (zero) */ - break; - - case REG_OP_ALLOC: - for (i = 0; i < nlongs_reg; i++) - bitmap[index + i] |= mask; - break; - - case REG_OP_RELEASE: - for (i = 0; i < nlongs_reg; i++) - bitmap[index + i] &= ~mask; - break; - } -done: - return ret; -} - /** * bitmap_find_free_region - find a contiguous aligned mem region * @bitmap: array of unsigned longs corresponding to the bitmap From 6cb42f91aa6dfd10fd847c469caebe63b35141ff Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Sun, 24 Sep 2023 19:38:17 -0700 Subject: [PATCH 12/13] bitmap: move bitmap_*_region() functions to bitmap.h Now that bitmap_*_region() functions are implemented as thin wrappers around others, it's worth to move them to the header, as it opens room for compile-time optimizations. CC: Andy Shevchenko CC: Rasmus Villemoes CC: Greg Kroah-Hartman Signed-off-by: Yury Norov --- include/linux/bitmap.h | 64 ++++++++++++++++++++++++++++++++++++++++-- lib/bitmap.c | 64 ------------------------------------------ 2 files changed, 61 insertions(+), 67 deletions(-) diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 1cca950a54ae..99451431e4d6 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -6,6 +6,7 @@ #include #include +#include #include #include #include @@ -209,9 +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); #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) @@ -497,6 +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 diff --git a/lib/bitmap.c b/lib/bitmap.c index 66da8c33fb1b..09522af227f1 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -8,7 +8,6 @@ #include #include #include -#include #include #include @@ -708,69 +707,6 @@ void bitmap_fold(unsigned long *dst, const unsigned long *orig, } #endif /* CONFIG_NUMA */ -/** - * 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. - * - * Return: the bit offset in bitmap of the allocated region, - * or -errno on failure. - */ -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; -} -EXPORT_SYMBOL(bitmap_find_free_region); - -/** - * 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). - */ -void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) -{ - bitmap_clear(bitmap, pos, BIT(order)); -} -EXPORT_SYMBOL(bitmap_release_region); - -/** - * 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. - * - * Return: 0 on success, or %-EBUSY if specified region wasn't - * free (not all bits were zero). - */ -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; -} -EXPORT_SYMBOL(bitmap_allocate_region); - unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) { return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), From bdcb37a5d8de3253da48b120e3f10863696fb654 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 17 Oct 2023 16:33:58 +0200 Subject: [PATCH 13/13] buildid: reduce header file dependencies for module The vmlinux decompressor code intentionally has only a limited set of included header files, but this started running into a build failure because of the bitmap logic needing linux/errno.h: In file included from include/linux/cpumask.h:12, from include/linux/mm_types_task.h:14, from include/linux/mm_types.h:5, from include/linux/buildid.h:5, from include/linux/module.h:14, from arch/arm/boot/compressed/../../../../lib/lz4/lz4_decompress.c:39, from arch/arm/boot/compressed/../../../../lib/decompress_unlz4.c:10, from arch/arm/boot/compressed/decompress.c:60: include/linux/bitmap.h: In function 'bitmap_allocate_region': include/linux/bitmap.h:527:25: error: 'EBUSY' undeclared (first use in this function) 527 | return -EBUSY; | ^~~~~ include/linux/bitmap.h:527:25: note: each undeclared identifier is reported only once for each function it appears in include/linux/bitmap.h: In function 'bitmap_find_free_region': include/linux/bitmap.h:554:17: error: 'ENOMEM' undeclared (first use in this function) 554 | return -ENOMEM; | ^~~~~~ This is easily avoided by changing linux/buildid.h to no longer depend on linux/mm_types.h, a header that pulls in a huge number of indirect dependencies. Fixes: b9c957f554442 ("bitmap: move bitmap_*_region() functions to bitmap.h") Fixes: bd7525dacd7e2 ("bpf: Move stack_map_get_build_id into lib") Signed-off-by: Arnd Bergmann Signed-off-by: Yury Norov --- include/linux/buildid.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/buildid.h b/include/linux/buildid.h index 3b7a0ff4642f..8a582d242f06 100644 --- a/include/linux/buildid.h +++ b/include/linux/buildid.h @@ -2,10 +2,11 @@ #ifndef _LINUX_BUILDID_H #define _LINUX_BUILDID_H -#include +#include #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);