writeback: split writeback_inodes_wb

[linux-2.6/next.git] / include / linux / nodemask.h

#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_scnprintf() and nodemask_parse_user(),
 * see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
 * For details of nodelist_scnprintf() and nodelist_parse(), see
 * bitmap_scnlistprintf() and 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
 *
 * int first_node(mask)                 Number lowest set bit, or MAX_NUMNODES
 * int next_node(node, mask)            Next node past 'node', or MAX_NUMNODES
 * 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_scnprintf(buf, len, mask) Format nodemask for printing
 * int nodemask_parse_user(ubuf, ulen, mask)    Parse ascii string as nodemask
 * int nodelist_scnprintf(buf, len, mask) Format nodemask as list for printing
 * 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_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/kernel.h>
#include <linux/threads.h>
#include <linux/bitmap.h>
#include <linux/numa.h>

typedef struct { DECLARE_BITMAP(bits, MAX_NUMNODES); } nodemask_t;
extern nodemask_t _unused_nodemask_arg_;

#define node_set(node, dst) __node_set((node), &(dst))
static inline void __node_set(int node, volatile nodemask_t *dstp)
{
        set_bit(node, dstp->bits);
}

#define node_clear(node, dst) __node_clear((node), &(dst))
static inline void __node_clear(int node, volatile nodemask_t *dstp)
{
        clear_bit(node, dstp->bits);
}

#define nodes_setall(dst) __nodes_setall(&(dst), MAX_NUMNODES)
static inline void __nodes_setall(nodemask_t *dstp, int nbits)
{
        bitmap_fill(dstp->bits, nbits);
}

#define nodes_clear(dst) __nodes_clear(&(dst), MAX_NUMNODES)
static inline void __nodes_clear(nodemask_t *dstp, int nbits)
{
        bitmap_zero(dstp->bits, nbits);
}

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

#define node_test_and_set(node, nodemask) \
                        __node_test_and_set((node), &(nodemask))
static inline int __node_test_and_set(int node, nodemask_t *addr)
{
        return test_and_set_bit(node, addr->bits);
}

#define nodes_and(dst, src1, src2) \
                        __nodes_and(&(dst), &(src1), &(src2), MAX_NUMNODES)
static inline void __nodes_and(nodemask_t *dstp, const nodemask_t *src1p,
                                        const nodemask_t *src2p, int nbits)
{
        bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
}

#define nodes_or(dst, src1, src2) \
                        __nodes_or(&(dst), &(src1), &(src2), MAX_NUMNODES)
static inline void __nodes_or(nodemask_t *dstp, const nodemask_t *src1p,
                                        const nodemask_t *src2p, int nbits)
{
        bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
}

#define nodes_xor(dst, src1, src2) \
                        __nodes_xor(&(dst), &(src1), &(src2), MAX_NUMNODES)
static inline void __nodes_xor(nodemask_t *dstp, const nodemask_t *src1p,
                                        const nodemask_t *src2p, int nbits)
{
        bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
}

#define nodes_andnot(dst, src1, src2) \
                        __nodes_andnot(&(dst), &(src1), &(src2), MAX_NUMNODES)
static inline void __nodes_andnot(nodemask_t *dstp, const nodemask_t *src1p,
                                        const nodemask_t *src2p, int nbits)
{
        bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
}

#define nodes_complement(dst, src) \
                        __nodes_complement(&(dst), &(src), MAX_NUMNODES)
static inline void __nodes_complement(nodemask_t *dstp,
                                        const nodemask_t *srcp, int nbits)
{
        bitmap_complement(dstp->bits, srcp->bits, nbits);
}

#define nodes_equal(src1, src2) \
                        __nodes_equal(&(src1), &(src2), MAX_NUMNODES)
static inline int __nodes_equal(const nodemask_t *src1p,
                                        const nodemask_t *src2p, int nbits)
{
        return bitmap_equal(src1p->bits, src2p->bits, nbits);
}

#define nodes_intersects(src1, src2) \
                        __nodes_intersects(&(src1), &(src2), MAX_NUMNODES)
static inline int __nodes_intersects(const nodemask_t *src1p,
                                        const nodemask_t *src2p, int nbits)
{
        return bitmap_intersects(src1p->bits, src2p->bits, nbits);
}

#define nodes_subset(src1, src2) \
                        __nodes_subset(&(src1), &(src2), MAX_NUMNODES)
static inline int __nodes_subset(const nodemask_t *src1p,
                                        const nodemask_t *src2p, int nbits)
{
        return bitmap_subset(src1p->bits, src2p->bits, nbits);
}

#define nodes_empty(src) __nodes_empty(&(src), MAX_NUMNODES)
static inline int __nodes_empty(const nodemask_t *srcp, int nbits)
{
        return bitmap_empty(srcp->bits, nbits);
}

#define nodes_full(nodemask) __nodes_full(&(nodemask), MAX_NUMNODES)
static inline int __nodes_full(const nodemask_t *srcp, int nbits)
{
        return bitmap_full(srcp->bits, nbits);
}

#define nodes_weight(nodemask) __nodes_weight(&(nodemask), MAX_NUMNODES)
static inline int __nodes_weight(const nodemask_t *srcp, int nbits)
{
        return bitmap_weight(srcp->bits, nbits);
}

#define nodes_shift_right(dst, src, n) \
                        __nodes_shift_right(&(dst), &(src), (n), MAX_NUMNODES)
static inline void __nodes_shift_right(nodemask_t *dstp,
                                        const nodemask_t *srcp, int n, int nbits)
{
        bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
}

#define nodes_shift_left(dst, src, n) \
                        __nodes_shift_left(&(dst), &(src), (n), MAX_NUMNODES)
static inline void __nodes_shift_left(nodemask_t *dstp,
                                        const nodemask_t *srcp, int n, int nbits)
{
        bitmap_shift_left(dstp->bits, srcp->bits, n, 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) __first_node(&(src))
static inline int __first_node(const nodemask_t *srcp)
{
        return min_t(int, MAX_NUMNODES, find_first_bit(srcp->bits, MAX_NUMNODES));
}

#define next_node(n, src) __next_node((n), &(src))
static inline int __next_node(int n, const nodemask_t *srcp)
{
        return min_t(int,MAX_NUMNODES,find_next_bit(srcp->bits, MAX_NUMNODES, n+1));
}

static inline void init_nodemask_of_node(nodemask_t *mask, int node)
{
        nodes_clear(*mask);
        node_set(node, *mask);
}

#define nodemask_of_node(node)                                          \
({                                                                      \
        typeof(_unused_nodemask_arg_) m;                                \
        if (sizeof(m) == sizeof(unsigned long)) {                       \
                m.bits[0] = 1UL << (node);                              \
        } else {                                                        \
                init_nodemask_of_node(&m, (node));                      \
        }                                                               \
        m;                                                              \
})

#define first_unset_node(mask) __first_unset_node(&(mask))
static inline int __first_unset_node(const nodemask_t *maskp)
{
        return min_t(int,MAX_NUMNODES,
                        find_first_zero_bit(maskp->bits, MAX_NUMNODES));
}

#define NODE_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(MAX_NUMNODES)

#if MAX_NUMNODES <= BITS_PER_LONG

#define NODE_MASK_ALL                                                   \
((nodemask_t) { {                                                       \
        [BITS_TO_LONGS(MAX_NUMNODES)-1] = NODE_MASK_LAST_WORD           \
} })

#else

#define NODE_MASK_ALL                                                   \
((nodemask_t) { {                                                       \
        [0 ... BITS_TO_LONGS(MAX_NUMNODES)-2] = ~0UL,                   \
        [BITS_TO_LONGS(MAX_NUMNODES)-1] = NODE_MASK_LAST_WORD           \
} })

#endif

#define NODE_MASK_NONE                                                  \
((nodemask_t) { {                                                       \
        [0 ... BITS_TO_LONGS(MAX_NUMNODES)-1] =  0UL                    \
} })

#define nodes_addr(src) ((src).bits)

#define nodemask_scnprintf(buf, len, src) \
                        __nodemask_scnprintf((buf), (len), &(src), MAX_NUMNODES)
static inline int __nodemask_scnprintf(char *buf, int len,
                                        const nodemask_t *srcp, int nbits)
{
        return bitmap_scnprintf(buf, len, srcp->bits, nbits);
}

#define nodemask_parse_user(ubuf, ulen, dst) \
                __nodemask_parse_user((ubuf), (ulen), &(dst), MAX_NUMNODES)
static inline int __nodemask_parse_user(const char __user *buf, int len,
                                        nodemask_t *dstp, int nbits)
{
        return bitmap_parse_user(buf, len, dstp->bits, nbits);
}

#define nodelist_scnprintf(buf, len, src) \
                        __nodelist_scnprintf((buf), (len), &(src), MAX_NUMNODES)
static inline int __nodelist_scnprintf(char *buf, int len,
                                        const nodemask_t *srcp, int nbits)
{
        return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
}

#define nodelist_parse(buf, dst) __nodelist_parse((buf), &(dst), MAX_NUMNODES)
static inline int __nodelist_parse(const char *buf, nodemask_t *dstp, int nbits)
{
        return bitmap_parselist(buf, dstp->bits, nbits);
}

#define node_remap(oldbit, old, new) \
                __node_remap((oldbit), &(old), &(new), MAX_NUMNODES)
static inline int __node_remap(int oldbit,
                const nodemask_t *oldp, const nodemask_t *newp, int nbits)
{
        return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
}

#define nodes_remap(dst, src, old, new) \
                __nodes_remap(&(dst), &(src), &(old), &(new), MAX_NUMNODES)
static inline void __nodes_remap(nodemask_t *dstp, const nodemask_t *srcp,
                const nodemask_t *oldp, const nodemask_t *newp, int nbits)
{
        bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
}

#define nodes_onto(dst, orig, relmap) \
                __nodes_onto(&(dst), &(orig), &(relmap), MAX_NUMNODES)
static inline void __nodes_onto(nodemask_t *dstp, const nodemask_t *origp,
                const nodemask_t *relmapp, int nbits)
{
        bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits);
}

#define nodes_fold(dst, orig, sz) \
                __nodes_fold(&(dst), &(orig), sz, MAX_NUMNODES)
static inline void __nodes_fold(nodemask_t *dstp, const nodemask_t *origp,
                int sz, int nbits)
{
        bitmap_fold(dstp->bits, origp->bits, sz, nbits);
}

#if MAX_NUMNODES > 1
#define for_each_node_mask(node, mask)                  \
        for ((node) = first_node(mask);                 \
                (node) < MAX_NUMNODES;                  \
                (node) = next_node((node), (mask)))
#else /* MAX_NUMNODES == 1 */
#define for_each_node_mask(node, mask)                  \
        if (!nodes_empty(mask))                         \
                for ((node) = 0; (node) < 1; (node)++)
#endif /* MAX_NUMNODES */

/*
 * Bitmasks that are kept for all the nodes.
 */
enum node_states {
        N_POSSIBLE,             /* The node could become online at some point */
        N_ONLINE,               /* The node is online */
        N_NORMAL_MEMORY,        /* The node has regular memory */
#ifdef CONFIG_HIGHMEM
        N_HIGH_MEMORY,          /* The node has regular or high memory */
#else
        N_HIGH_MEMORY = N_NORMAL_MEMORY,
#endif
        N_CPU,          /* The node has one or more cpus */
        NR_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 inline int node_state(int node, enum node_states state)
{
        return node_isset(node, node_states[state]);
}

static inline void node_set_state(int node, enum node_states state)
{
        __node_set(node, &node_states[state]);
}

static inline void node_clear_state(int node, enum node_states state)
{
        __node_clear(node, &node_states[state]);
}

static inline int num_node_state(enum node_states state)
{
        return nodes_weight(node_states[state]);
}

#define for_each_node_state(__node, __state) \
        for_each_node_mask((__node), node_states[__state])

#define first_online_node       first_node(node_states[N_ONLINE])
#define next_online_node(nid)   next_node((nid), node_states[N_ONLINE])

extern int nr_node_ids;
extern int nr_online_nodes;

static inline void node_set_online(int nid)
{
        node_set_state(nid, N_ONLINE);
        nr_online_nodes = num_node_state(N_ONLINE);
}

static inline void node_set_offline(int nid)
{
        node_clear_state(nid, N_ONLINE);
        nr_online_nodes = num_node_state(N_ONLINE);
}
#else

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

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

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

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

#define for_each_node_state(node, __state) \
        for ( (node) = 0; (node) == 0; (node) = 1)

#define first_online_node       0
#define next_online_node(nid)   (MAX_NUMNODES)
#define nr_node_ids             1
#define nr_online_nodes         1

#define node_set_online(node)      node_set_state((node), N_ONLINE)
#define node_set_offline(node)     node_clear_state((node), N_ONLINE)
#endif

#define node_online_map         node_states[N_ONLINE]
#define node_possible_map       node_states[N_POSSIBLE]

#define num_online_nodes()      num_node_state(N_ONLINE)
#define num_possible_nodes()    num_node_state(N_POSSIBLE)
#define node_online(node)       node_state((node), N_ONLINE)
#define node_possible(node)     node_state((node), N_POSSIBLE)

#define for_each_node(node)        for_each_node_state(node, N_POSSIBLE)
#define for_each_online_node(node) for_each_node_state(node, N_ONLINE)

/*
 * For nodemask scrach area.
 * NODEMASK_ALLOC(type, name) allocates an object with a specified type and
 * name.
 */
#if NODES_SHIFT > 8 /* nodemask_t > 256 bytes */
#define NODEMASK_ALLOC(type, name, gfp_flags)   \
                        type *name = kmalloc(sizeof(*name), gfp_flags)
#define NODEMASK_FREE(m)                        kfree(m)
#else
#define NODEMASK_ALLOC(type, name, gfp_flags)   type _##name, *name = &_##name
#define NODEMASK_FREE(m)                        do {} while (0)
#endif

/* A example struture for using NODEMASK_ALLOC, used in mempolicy. */
struct nodemask_scratch {
        nodemask_t      mask1;
        nodemask_t      mask2;
};

#define NODEMASK_SCRATCH(x)                                             \
                        NODEMASK_ALLOC(struct nodemask_scratch, x,      \
                                        GFP_KERNEL | __GFP_NORETRY)
#define NODEMASK_SCRATCH_FREE(x)        NODEMASK_FREE(x)


#endif /* __LINUX_NODEMASK_H */