linux/include/linux/nodemask.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_NODEMASK_H
#define __LINUX_NODEMASK_H

/*
 * Nodemasks provide a bitmap suitable for representing the
 * set of Node's in a system, one bit position per Node number.
 *
 * See detailed comments in the file linux/bitmap.h describing the
 * data type on which these nodemasks are based.
 *
 * For details of nodemask_parse_user(), see bitmap_parse_user() in
 * lib/bitmap.c.  For details of nodelist_parse(), see bitmap_parselist(),
 * also in bitmap.c.  For details of node_remap(), see bitmap_bitremap in
 * lib/bitmap.c.  For details of nodes_remap(), see bitmap_remap in
 * lib/bitmap.c.  For details of nodes_onto(), see bitmap_onto in
 * lib/bitmap.c.  For details of nodes_fold(), see bitmap_fold in
 * lib/bitmap.c.
 *
 * The available nodemask operations are:
 *
 * void node_set(node, mask)		turn on bit 'node' in mask
 * void node_clear(node, mask)		turn off bit 'node' in mask
 * void nodes_setall(mask)		set all bits
 * void nodes_clear(mask)		clear all bits
 * int node_isset(node, mask)		true iff bit 'node' set in mask
 * int node_test_and_set(node, mask)	test and set bit 'node' in mask
 *
 * void nodes_and(dst, src1, src2)	dst = src1 & src2  [intersection]
 * void nodes_or(dst, src1, src2)	dst = src1 | src2  [union]
 * void nodes_xor(dst, src1, src2)	dst = src1 ^ src2
 * void nodes_andnot(dst, src1, src2)	dst = src1 & ~src2
 * void nodes_complement(dst, src)	dst = ~src
 *
 * int nodes_equal(mask1, mask2)	Does mask1 == mask2?
 * int nodes_intersects(mask1, mask2)	Do mask1 and mask2 intersect?
 * int nodes_subset(mask1, mask2)	Is mask1 a subset of mask2?
 * int nodes_empty(mask)		Is mask empty (no bits sets)?
 * int nodes_full(mask)			Is mask full (all bits sets)?
 * int nodes_weight(mask)		Hamming weight - number of set bits
 *
 * void nodes_shift_right(dst, src, n)	Shift right
 * void nodes_shift_left(dst, src, n)	Shift left
 *
 * unsigned int first_node(mask)	Number lowest set bit, or MAX_NUMNODES
 * unsigend int next_node(node, mask)	Next node past 'node', or MAX_NUMNODES
 * unsigned int next_node_in(node, mask) Next node past 'node', or wrap to first,
 *					or MAX_NUMNODES
 * unsigned int first_unset_node(mask)	First node not set in mask, or
 *					MAX_NUMNODES
 *
 * nodemask_t nodemask_of_node(node)	Return nodemask with bit 'node' set
 * NODE_MASK_ALL			Initializer - all bits set
 * NODE_MASK_NONE			Initializer - no bits set
 * unsigned long *nodes_addr(mask)	Array of unsigned long's in mask
 *
 * int nodemask_parse_user(ubuf, ulen, mask)	Parse ascii string as nodemask
 * int nodelist_parse(buf, map)		Parse ascii string as nodelist
 * int node_remap(oldbit, old, new)	newbit = map(old, new)(oldbit)
 * void nodes_remap(dst, src, old, new)	*dst = map(old, new)(src)
 * void nodes_onto(dst, orig, relmap)	*dst = orig relative to relmap
 * void nodes_fold(dst, orig, sz)	dst bits = orig bits mod sz
 *
 * for_each_node_mask(node, mask)	for-loop node over mask
 *
 * int num_online_nodes()		Number of online Nodes
 * int num_possible_nodes()		Number of all possible Nodes
 *
 * int node_random(mask)		Random node with set bit in mask
 *
 * int node_online(node)		Is some node online?
 * int node_possible(node)		Is some node possible?
 *
 * node_set_online(node)		set bit 'node' in node_online_map
 * node_set_offline(node)		clear bit 'node' in node_online_map
 *
 * for_each_node(node)			for-loop node over node_possible_map
 * for_each_online_node(node)		for-loop node over node_online_map
 *
 * Subtlety:
 * 1) The 'type-checked' form of node_isset() causes gcc (3.3.2, anyway)
 *    to generate slightly worse code.  So use a simple one-line #define
 *    for node_isset(), instead of wrapping an inline inside a macro, the
 *    way we do the other calls.
 *
 * NODEMASK_SCRATCH
 * When doing above logical AND, OR, XOR, Remap operations the callers tend to
 * need temporary nodemask_t's on the stack. But if NODES_SHIFT is large,
 * nodemask_t's consume too much stack space.  NODEMASK_SCRATCH is a helper
 * for such situations. See below and CPUMASK_ALLOC also.
 */

#include <linux/threads.h>
#include <linux/bitmap.h>
#include <linux/minmax.h>
#include <linux/nodemask_types.h>
#include <linux/numa.h>
#include <linux/random.h>

extern nodemask_t _unused_nodemask_arg_;

/**
 * nodemask_pr_args - printf args to output a nodemask
 * @maskp: nodemask to be printed
 *
 * Can be used to provide arguments for '%*pb[l]' when printing a nodemask.
 */
#define nodemask_pr_args(maskp)
static __always_inline unsigned int __nodemask_pr_numnodes(const nodemask_t *m)
{}
static __always_inline const unsigned long *__nodemask_pr_bits(const nodemask_t *m)
{}

/*
 * The inline keyword gives the compiler room to decide to inline, or
 * not inline a function as it sees best.  However, as these functions
 * are called in both __init and non-__init functions, if they are not
 * inlined we will end up with a section mismatch error (of the type of
 * freeable items not being freed).  So we must use __always_inline here
 * to fix the problem.  If other functions in the future also end up in
 * this situation they will also need to be annotated as __always_inline
 */
#define node_set(node, dst)
static __always_inline void __node_set(int node, volatile nodemask_t *dstp)
{}

#define node_clear(node, dst)
static __always_inline void __node_clear(int node, volatile nodemask_t *dstp)
{}

#define nodes_setall(dst)
static __always_inline void __nodes_setall(nodemask_t *dstp, unsigned int nbits)
{}

#define nodes_clear(dst)
static __always_inline void __nodes_clear(nodemask_t *dstp, unsigned int nbits)
{}

/* No static inline type checking - see Subtlety (1) above. */
#define node_isset(node, nodemask)

#define node_test_and_set(node, nodemask)
static __always_inline bool __node_test_and_set(int node, nodemask_t *addr)
{}

#define nodes_and(dst, src1, src2)
static __always_inline void __nodes_and(nodemask_t *dstp, const nodemask_t *src1p,
					const nodemask_t *src2p, unsigned int nbits)
{}

#define nodes_or(dst, src1, src2)
static __always_inline void __nodes_or(nodemask_t *dstp, const nodemask_t *src1p,
					const nodemask_t *src2p, unsigned int nbits)
{}

#define nodes_xor(dst, src1, src2)
static __always_inline void __nodes_xor(nodemask_t *dstp, const nodemask_t *src1p,
					const nodemask_t *src2p, unsigned int nbits)
{}

#define nodes_andnot(dst, src1, src2)
static __always_inline void __nodes_andnot(nodemask_t *dstp, const nodemask_t *src1p,
					const nodemask_t *src2p, unsigned int nbits)
{}

#define nodes_complement(dst, src)
static __always_inline void __nodes_complement(nodemask_t *dstp,
					const nodemask_t *srcp, unsigned int nbits)
{}

#define nodes_equal(src1, src2)
static __always_inline bool __nodes_equal(const nodemask_t *src1p,
					const nodemask_t *src2p, unsigned int nbits)
{}

#define nodes_intersects(src1, src2)
static __always_inline bool __nodes_intersects(const nodemask_t *src1p,
					const nodemask_t *src2p, unsigned int nbits)
{}

#define nodes_subset(src1, src2)
static __always_inline bool __nodes_subset(const nodemask_t *src1p,
					const nodemask_t *src2p, unsigned int nbits)
{}

#define nodes_empty(src)
static __always_inline bool __nodes_empty(const nodemask_t *srcp, unsigned int nbits)
{}

#define nodes_full(nodemask)
static __always_inline bool __nodes_full(const nodemask_t *srcp, unsigned int nbits)
{}

#define nodes_weight(nodemask)
static __always_inline int __nodes_weight(const nodemask_t *srcp, unsigned int nbits)
{}

#define nodes_shift_right(dst, src, n)
static __always_inline void __nodes_shift_right(nodemask_t *dstp,
					const nodemask_t *srcp, int n, int nbits)
{}

#define nodes_shift_left(dst, src, n)
static __always_inline void __nodes_shift_left(nodemask_t *dstp,
					const nodemask_t *srcp, int n, int nbits)
{}

/* FIXME: better would be to fix all architectures to never return
          > MAX_NUMNODES, then the silly min_ts could be dropped. */

#define first_node(src)
static __always_inline unsigned int __first_node(const nodemask_t *srcp)
{}

#define next_node(n, src)
static __always_inline unsigned int __next_node(int n, const nodemask_t *srcp)
{}

/*
 * Find the next present node in src, starting after node n, wrapping around to
 * the first node in src if needed.  Returns MAX_NUMNODES if src is empty.
 */
#define next_node_in(n, src)
static __always_inline unsigned int __next_node_in(int node, const nodemask_t *srcp)
{}

static __always_inline void init_nodemask_of_node(nodemask_t *mask, int node)
{}

#define nodemask_of_node(node)

#define first_unset_node(mask)
static __always_inline unsigned int __first_unset_node(const nodemask_t *maskp)
{}

#define NODE_MASK_LAST_WORD

#if MAX_NUMNODES <= BITS_PER_LONG

#define NODE_MASK_ALL

#else

#define NODE_MASK_ALL

#endif

#define NODE_MASK_NONE

#define nodes_addr(src)

#define nodemask_parse_user(ubuf, ulen, dst)
static __always_inline int __nodemask_parse_user(const char __user *buf, int len,
					nodemask_t *dstp, int nbits)
{}

#define nodelist_parse(buf, dst)
static __always_inline int __nodelist_parse(const char *buf, nodemask_t *dstp, int nbits)
{}

#define node_remap(oldbit, old, new)
static __always_inline int __node_remap(int oldbit,
		const nodemask_t *oldp, const nodemask_t *newp, int nbits)
{}

#define nodes_remap(dst, src, old, new)
static __always_inline void __nodes_remap(nodemask_t *dstp, const nodemask_t *srcp,
		const nodemask_t *oldp, const nodemask_t *newp, int nbits)
{}

#define nodes_onto(dst, orig, relmap)
static __always_inline void __nodes_onto(nodemask_t *dstp, const nodemask_t *origp,
		const nodemask_t *relmapp, int nbits)
{}

#define nodes_fold(dst, orig, sz)
static __always_inline void __nodes_fold(nodemask_t *dstp, const nodemask_t *origp,
		int sz, int nbits)
{}

#if MAX_NUMNODES > 1
#define for_each_node_mask(node, mask)
#else /* MAX_NUMNODES == 1 */
#define for_each_node_mask
#endif /* MAX_NUMNODES */

/*
 * Bitmasks that are kept for all the nodes.
 */
enum node_states {};

/*
 * The following particular system nodemasks and operations
 * on them manage all possible and online nodes.
 */

extern nodemask_t node_states[NR_NODE_STATES];

#if MAX_NUMNODES > 1
static __always_inline int node_state(int node, enum node_states state)
{}

static __always_inline void node_set_state(int node, enum node_states state)
{}

static __always_inline void node_clear_state(int node, enum node_states state)
{}

static __always_inline int num_node_state(enum node_states state)
{}

#define for_each_node_state(__node, __state)

#define first_online_node
#define first_memory_node
static __always_inline unsigned int next_online_node(int nid)
{}
static __always_inline unsigned int next_memory_node(int nid)
{}

extern unsigned int nr_node_ids;
extern unsigned int nr_online_nodes;

static __always_inline void node_set_online(int nid)
{}

static __always_inline void node_set_offline(int nid)
{}

#else

static __always_inline int node_state(int node, enum node_states state)
{
	return node == 0;
}

static __always_inline void node_set_state(int node, enum node_states state)
{
}

static __always_inline void node_clear_state(int node, enum node_states state)
{
}

static __always_inline int num_node_state(enum node_states state)
{
	return 1;
}

#define for_each_node_state

#define first_online_node
#define first_memory_node
#define next_online_node
#define next_memory_node
#define nr_node_ids
#define nr_online_nodes

#define node_set_online
#define node_set_offline

#endif

static __always_inline int node_random(const nodemask_t *maskp)
{}

#define node_online_map
#define node_possible_map

#define num_online_nodes()
#define num_possible_nodes()
#define node_online(node)
#define node_possible(node)

#define for_each_node(node)
#define for_each_online_node(node)

/*
 * For nodemask scratch area.
 * NODEMASK_ALLOC(type, name) allocates an object with a specified type and
 * name.
 */
#if NODES_SHIFT > 8 /* nodemask_t > 32 bytes */
#define NODEMASK_ALLOC(type, name, gfp_flags)
#define NODEMASK_FREE(m)
#else
#define NODEMASK_ALLOC
#define NODEMASK_FREE
#endif

/* Example structure for using NODEMASK_ALLOC, used in mempolicy. */
struct nodemask_scratch {};

#define NODEMASK_SCRATCH(x)
#define NODEMASK_SCRATCH_FREE(x)


#endif /* __LINUX_NODEMASK_H */