From: Yury Norov <yury.norov@xxxxxxxxxx> Many core headers, like sched.h, include cpumask.h mostly for struct cpumask and cpumask_var_t. Those are frequently used headers and shouldn't pull more than the bare minimum. Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx> --- MAINTAINERS | 1 + include/linux/cpumask.h | 56 +---------------------------- include/linux/cpumask_types.h | 66 +++++++++++++++++++++++++++++++++++ 3 files changed, 68 insertions(+), 55 deletions(-) create mode 100644 include/linux/cpumask_types.h diff --git a/MAINTAINERS b/MAINTAINERS index 6ae73aaee305..c4fa8f264156 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3731,6 +3731,7 @@ F: include/linux/bitmap-str.h F: include/linux/bitmap.h F: include/linux/bits.h F: include/linux/cpumask.h +F: include/linux/cpumask_types.h F: include/linux/find.h F: include/linux/nodemask.h F: include/linux/nodemask_types.h diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 18410acdbc9e..79262a9ef03b 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -9,25 +9,13 @@ */ #include <linux/cleanup.h> #include <linux/kernel.h> -#include <linux/threads.h> #include <linux/bitmap.h> +#include <linux/cpumask_types.h> #include <linux/atomic.h> #include <linux/bug.h> #include <linux/gfp_types.h> #include <linux/numa.h> -/* Don't assign or return these: may not be this big! */ -typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t; - -/** - * cpumask_bits - get the bits in a cpumask - * @maskp: the struct cpumask * - * - * You should only assume nr_cpu_ids bits of this mask are valid. This is - * a macro so it's const-correct. - */ -#define cpumask_bits(maskp) ((maskp)->bits) - /** * cpumask_pr_args - printf args to output a cpumask * @maskp: cpumask to be printed @@ -922,48 +910,7 @@ static inline unsigned int cpumask_size(void) return bitmap_size(large_cpumask_bits); } -/* - * cpumask_var_t: struct cpumask for stack usage. - * - * Oh, the wicked games we play! In order to make kernel coding a - * 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. - * - * i.e. - * cpumask_var_t tmpmask; - * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) - * return -ENOMEM; - * - * ... use 'tmpmask' like a normal struct cpumask * ... - * - * free_cpumask_var(tmpmask); - * - * - * However, one notable exception is there. alloc_cpumask_var() allocates - * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has - * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t. - * - * cpumask_var_t tmpmask; - * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) - * return -ENOMEM; - * - * var = *tmpmask; - * - * This code makes NR_CPUS length memcopy and brings to a memory corruption. - * cpumask_copy() provide safe copy functionality. - * - * Note that there is another evil here: If you define a cpumask_var_t - * as a percpu variable then the way to obtain the address of the cpumask - * structure differently influences what this_cpu_* operation needs to be - * used. Please use this_cpu_cpumask_var_t in those cases. The direct use - * of this_cpu_ptr() or this_cpu_read() will lead to failures when the - * other type of cpumask_var_t implementation is configured. - * - * Please also note that __cpumask_var_read_mostly can be used to declare - * a cpumask_var_t variable itself (not its content) as read mostly. - */ #ifdef CONFIG_CPUMASK_OFFSTACK -typedef struct cpumask *cpumask_var_t; #define this_cpu_cpumask_var_ptr(x) this_cpu_read(x) #define __cpumask_var_read_mostly __read_mostly @@ -1010,7 +957,6 @@ static inline bool cpumask_available(cpumask_var_t mask) } #else -typedef struct cpumask cpumask_var_t[1]; #define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x) #define __cpumask_var_read_mostly diff --git a/include/linux/cpumask_types.h b/include/linux/cpumask_types.h new file mode 100644 index 000000000000..461ed1b6bcdb --- /dev/null +++ b/include/linux/cpumask_types.h @@ -0,0 +1,66 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_CPUMASK_TYPES_H +#define __LINUX_CPUMASK_TYPES_H + +#include <linux/bitops.h> +#include <linux/threads.h> + +/* Don't assign or return these: may not be this big! */ +typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t; + +/** + * cpumask_bits - get the bits in a cpumask + * @maskp: the struct cpumask * + * + * You should only assume nr_cpu_ids bits of this mask are valid. This is + * a macro so it's const-correct. + */ +#define cpumask_bits(maskp) ((maskp)->bits) + +/* + * cpumask_var_t: struct cpumask for stack usage. + * + * Oh, the wicked games we play! In order to make kernel coding a + * 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. + * + * i.e. + * cpumask_var_t tmpmask; + * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) + * return -ENOMEM; + * + * ... use 'tmpmask' like a normal struct cpumask * ... + * + * free_cpumask_var(tmpmask); + * + * + * However, one notable exception is there. alloc_cpumask_var() allocates + * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has + * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t. + * + * cpumask_var_t tmpmask; + * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) + * return -ENOMEM; + * + * var = *tmpmask; + * + * This code makes NR_CPUS length memcopy and brings to a memory corruption. + * cpumask_copy() provide safe copy functionality. + * + * Note that there is another evil here: If you define a cpumask_var_t + * as a percpu variable then the way to obtain the address of the cpumask + * structure differently influences what this_cpu_* operation needs to be + * used. Please use this_cpu_cpumask_var_t in those cases. The direct use + * of this_cpu_ptr() or this_cpu_read() will lead to failures when the + * other type of cpumask_var_t implementation is configured. + * + * Please also note that __cpumask_var_read_mostly can be used to declare + * a cpumask_var_t variable itself (not its content) as read mostly. + */ +#ifdef CONFIG_CPUMASK_OFFSTACK +typedef struct cpumask *cpumask_var_t; +#else +typedef struct cpumask cpumask_var_t[1]; +#endif /* CONFIG_CPUMASK_OFFSTACK */ + +#endif /* __LINUX_CPUMASK_TYPES_H */ -- 2.40.1