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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667/* 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_OFFSTACKtypedef struct cpumask *cpumask_var_t;#elsetypedef struct cpumask cpumask_var_t[1];#endif /* CONFIG_CPUMASK_OFFSTACK */
#endif /* __LINUX_CPUMASK_TYPES_H */