1 files changed, 395 insertions, 0 deletions

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
new file mode 100644
index 000000000000..b15826f6e3a2
--- /dev/null
+++ b/include/linux/cpumask.h
@@ -0,0 +1,395 @@
+#ifndef __LINUX_CPUMASK_H
+#define __LINUX_CPUMASK_H
+
+/*
+ * Cpumasks provide a bitmap suitable for representing the
+ * set of CPU's in a system, one bit position per CPU number.
+ *
+ * See detailed comments in the file linux/bitmap.h describing the
+ * data type on which these cpumasks are based.
+ *
+ * For details of cpumask_scnprintf() and cpumask_parse(),
+ * see bitmap_scnprintf() and bitmap_parse() in lib/bitmap.c.
+ * For details of cpulist_scnprintf() and cpulist_parse(), see
+ * bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
+ *
+ * The available cpumask operations are:
+ *
+ * void cpu_set(cpu, mask)              turn on bit 'cpu' in mask
+ * void cpu_clear(cpu, mask)            turn off bit 'cpu' in mask
+ * void cpus_setall(mask)               set all bits
+ * void cpus_clear(mask)                clear all bits
+ * int cpu_isset(cpu, mask)             true iff bit 'cpu' set in mask
+ * int cpu_test_and_set(cpu, mask)      test and set bit 'cpu' in mask
+ *
+ * void cpus_and(dst, src1, src2)       dst = src1 & src2  [intersection]
+ * void cpus_or(dst, src1, src2)        dst = src1 | src2  [union]
+ * void cpus_xor(dst, src1, src2)       dst = src1 ^ src2
+ * void cpus_andnot(dst, src1, src2)    dst = src1 & ~src2
+ * void cpus_complement(dst, src)       dst = ~src
+ *
+ * int cpus_equal(mask1, mask2)         Does mask1 == mask2?
+ * int cpus_intersects(mask1, mask2)    Do mask1 and mask2 intersect?
+ * int cpus_subset(mask1, mask2)        Is mask1 a subset of mask2?
+ * int cpus_empty(mask)                 Is mask empty (no bits sets)?
+ * int cpus_full(mask)                  Is mask full (all bits sets)?
+ * int cpus_weight(mask)                Hamming weigh - number of set bits
+ *
+ * void cpus_shift_right(dst, src, n)   Shift right
+ * void cpus_shift_left(dst, src, n)    Shift left
+ *
+ * int first_cpu(mask)                  Number lowest set bit, or NR_CPUS
+ * int next_cpu(cpu, mask)              Next cpu past 'cpu', or NR_CPUS
+ *
+ * cpumask_t cpumask_of_cpu(cpu)        Return cpumask with bit 'cpu' set
+ * CPU_MASK_ALL                         Initializer - all bits set
+ * CPU_MASK_NONE                        Initializer - no bits set
+ * unsigned long *cpus_addr(mask)       Array of unsigned long's in mask
+ *
+ * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
+ * int cpumask_parse(ubuf, ulen, mask)  Parse ascii string as cpumask
+ * int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
+ * int cpulist_parse(buf, map)          Parse ascii string as cpulist
+ *
+ * for_each_cpu_mask(cpu, mask)         for-loop cpu over mask
+ *
+ * int num_online_cpus()                Number of online CPUs
+ * int num_possible_cpus()              Number of all possible CPUs
+ * int num_present_cpus()               Number of present CPUs
+ *
+ * int cpu_online(cpu)                  Is some cpu online?
+ * int cpu_possible(cpu)                Is some cpu possible?
+ * int cpu_present(cpu)                 Is some cpu present (can schedule)?
+ *
+ * int any_online_cpu(mask)             First online cpu in mask
+ *
+ * for_each_cpu(cpu)                    for-loop cpu over cpu_possible_map
+ * for_each_online_cpu(cpu)             for-loop cpu over cpu_online_map
+ * for_each_present_cpu(cpu)            for-loop cpu over cpu_present_map
+ *
+ * Subtlety:
+ * 1) The 'type-checked' form of cpu_isset() causes gcc (3.3.2, anyway)
+ *    to generate slightly worse code.  Note for example the additional
+ *    40 lines of assembly code compiling the "for each possible cpu"
+ *    loops buried in the disk_stat_read() macros calls when compiling
+ *    drivers/block/genhd.c (arch i386, CONFIG_SMP=y).  So use a simple
+ *    one-line #define for cpu_isset(), instead of wrapping an inline
+ *    inside a macro, the way we do the other calls.
+ */
+
+#include <linux/kernel.h>
+#include <linux/threads.h>
+#include <linux/bitmap.h>
+#include <asm/bug.h>
+
+typedef struct { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
+extern cpumask_t _unused_cpumask_arg_;
+
+#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
+static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
+{
+        set_bit(cpu, dstp->bits);
+}
+
+#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
+static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
+{
+        clear_bit(cpu, dstp->bits);
+}
+
+#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
+static inline void __cpus_setall(cpumask_t *dstp, int nbits)
+{
+        bitmap_fill(dstp->bits, nbits);
+}
+
+#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
+static inline void __cpus_clear(cpumask_t *dstp, int nbits)
+{
+        bitmap_zero(dstp->bits, nbits);
+}
+
+/* No static inline type checking - see Subtlety (1) above. */
+#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
+
+#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
+static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
+{
+        return test_and_set_bit(cpu, addr->bits);
+}
+
+#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
+static inline void __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
+                                        const cpumask_t *src2p, int nbits)
+{
+        bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
+}
+
+#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
+static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
+                                        const cpumask_t *src2p, int nbits)
+{
+        bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
+}
+
+#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
+static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
+                                        const cpumask_t *src2p, int nbits)
+{
+        bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
+}
+
+#define cpus_andnot(dst, src1, src2) \
+                                __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
+static inline void __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
+                                        const cpumask_t *src2p, int nbits)
+{
+        bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
+}
+
+#define cpus_complement(dst, src) __cpus_complement(&(dst), &(src), NR_CPUS)
+static inline void __cpus_complement(cpumask_t *dstp,
+                                        const cpumask_t *srcp, int nbits)
+{
+        bitmap_complement(dstp->bits, srcp->bits, nbits);
+}
+
+#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
+static inline int __cpus_equal(const cpumask_t *src1p,
+                                        const cpumask_t *src2p, int nbits)
+{
+        return bitmap_equal(src1p->bits, src2p->bits, nbits);
+}
+
+#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
+static inline int __cpus_intersects(const cpumask_t *src1p,
+                                        const cpumask_t *src2p, int nbits)
+{
+        return bitmap_intersects(src1p->bits, src2p->bits, nbits);
+}
+
+#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
+static inline int __cpus_subset(const cpumask_t *src1p,
+                                        const cpumask_t *src2p, int nbits)
+{
+        return bitmap_subset(src1p->bits, src2p->bits, nbits);
+}
+
+#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
+static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
+{
+        return bitmap_empty(srcp->bits, nbits);
+}
+
+#define cpus_full(cpumask) __cpus_full(&(cpumask), NR_CPUS)
+static inline int __cpus_full(const cpumask_t *srcp, int nbits)
+{
+        return bitmap_full(srcp->bits, nbits);
+}
+
+#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
+static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
+{
+        return bitmap_weight(srcp->bits, nbits);
+}
+
+#define cpus_shift_right(dst, src, n) \
+                        __cpus_shift_right(&(dst), &(src), (n), NR_CPUS)
+static inline void __cpus_shift_right(cpumask_t *dstp,
+                                        const cpumask_t *srcp, int n, int nbits)
+{
+        bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
+}
+
+#define cpus_shift_left(dst, src, n) \
+                        __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
+static inline void __cpus_shift_left(cpumask_t *dstp,
+                                        const cpumask_t *srcp, int n, int nbits)
+{
+        bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
+}
+
+#define first_cpu(src) __first_cpu(&(src), NR_CPUS)
+static inline int __first_cpu(const cpumask_t *srcp, int nbits)
+{
+        return min_t(int, nbits, find_first_bit(srcp->bits, nbits));
+}
+
+#define next_cpu(n, src) __next_cpu((n), &(src), NR_CPUS)
+static inline int __next_cpu(int n, const cpumask_t *srcp, int nbits)
+{
+        return min_t(int, nbits, find_next_bit(srcp->bits, nbits, n+1));
+}
+
+#define cpumask_of_cpu(cpu)                                             \
+({                                                                      \
+        typeof(_unused_cpumask_arg_) m;                                 \
+        if (sizeof(m) == sizeof(unsigned long)) {                       \
+                m.bits[0] = 1UL<<(cpu);                                 \
+        } else {                                                        \
+                cpus_clear(m);                                          \
+                cpu_set((cpu), m);                                      \
+        }                                                               \
+        m;                                                              \
+})
+
+#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
+
+#if NR_CPUS <= BITS_PER_LONG
+
+#define CPU_MASK_ALL                                                    \
+(cpumask_t) { {                                                         \
+        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
+} }
+
+#else
+
+#define CPU_MASK_ALL                                                    \
+(cpumask_t) { {                                                         \
+        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
+        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
+} }
+
+#endif
+
+#define CPU_MASK_NONE                                                   \
+(cpumask_t) { {                                                         \
+        [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
+} }
+
+#define CPU_MASK_CPU0                                                   \
+(cpumask_t) { {                                                         \
+        [0] =  1UL                                                      \
+} }
+
+#define cpus_addr(src) ((src).bits)
+
+#define cpumask_scnprintf(buf, len, src) \
+                        __cpumask_scnprintf((buf), (len), &(src), NR_CPUS)
+static inline int __cpumask_scnprintf(char *buf, int len,
+                                        const cpumask_t *srcp, int nbits)
+{
+        return bitmap_scnprintf(buf, len, srcp->bits, nbits);
+}
+
+#define cpumask_parse(ubuf, ulen, dst) \
+                        __cpumask_parse((ubuf), (ulen), &(dst), NR_CPUS)
+static inline int __cpumask_parse(const char __user *buf, int len,
+                                        cpumask_t *dstp, int nbits)
+{
+        return bitmap_parse(buf, len, dstp->bits, nbits);
+}
+
+#define cpulist_scnprintf(buf, len, src) \
+                        __cpulist_scnprintf((buf), (len), &(src), NR_CPUS)
+static inline int __cpulist_scnprintf(char *buf, int len,
+                                        const cpumask_t *srcp, int nbits)
+{
+        return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
+}
+
+#define cpulist_parse(buf, dst) __cpulist_parse((buf), &(dst), NR_CPUS)
+static inline int __cpulist_parse(const char *buf, cpumask_t *dstp, int nbits)
+{
+        return bitmap_parselist(buf, dstp->bits, nbits);
+}
+
+#if NR_CPUS > 1
+#define for_each_cpu_mask(cpu, mask)            \
+        for ((cpu) = first_cpu(mask);           \
+                (cpu) < NR_CPUS;                \
+                (cpu) = next_cpu((cpu), (mask)))
+#else /* NR_CPUS == 1 */
+#define for_each_cpu_mask(cpu, mask) for ((cpu) = 0; (cpu) < 1; (cpu)++)
+#endif /* NR_CPUS */
+
+/*
+ * The following particular system cpumasks and operations manage
+ * possible, present and online cpus.  Each of them is a fixed size
+ * bitmap of size NR_CPUS.
+ *
+ *  #ifdef CONFIG_HOTPLUG_CPU
+ *     cpu_possible_map - all NR_CPUS bits set
+ *     cpu_present_map  - has bit 'cpu' set iff cpu is populated
+ *     cpu_online_map   - has bit 'cpu' set iff cpu available to scheduler
+ *  #else
+ *     cpu_possible_map - has bit 'cpu' set iff cpu is populated
+ *     cpu_present_map  - copy of cpu_possible_map
+ *     cpu_online_map   - has bit 'cpu' set iff cpu available to scheduler
+ *  #endif
+ *
+ *  In either case, NR_CPUS is fixed at compile time, as the static
+ *  size of these bitmaps.  The cpu_possible_map is fixed at boot
+ *  time, as the set of CPU id's that it is possible might ever
+ *  be plugged in at anytime during the life of that system boot.
+ *  The cpu_present_map is dynamic(*), representing which CPUs
+ *  are currently plugged in.  And cpu_online_map is the dynamic
+ *  subset of cpu_present_map, indicating those CPUs available
+ *  for scheduling.
+ *
+ *  If HOTPLUG is enabled, then cpu_possible_map is forced to have
+ *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
+ *  ACPI reports present at boot.
+ *
+ *  If HOTPLUG is enabled, then cpu_present_map varies dynamically,
+ *  depending on what ACPI reports as currently plugged in, otherwise
+ *  cpu_present_map is just a copy of cpu_possible_map.
+ *
+ *  (*) Well, cpu_present_map is dynamic in the hotplug case.  If not
+ *      hotplug, it's a copy of cpu_possible_map, hence fixed at boot.
+ *
+ * Subtleties:
+ * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
+ *    assumption that their single CPU is online.  The UP
+ *    cpu_{online,possible,present}_maps are placebos.  Changing them
+ *    will have no useful affect on the following num_*_cpus()
+ *    and cpu_*() macros in the UP case.  This ugliness is a UP
+ *    optimization - don't waste any instructions or memory references
+ *    asking if you're online or how many CPUs there are if there is
+ *    only one CPU.
+ * 2) Most SMP arch's #define some of these maps to be some
+ *    other map specific to that arch.  Therefore, the following
+ *    must be #define macros, not inlines.  To see why, examine
+ *    the assembly code produced by the following.  Note that
+ *    set1() writes phys_x_map, but set2() writes x_map:
+ *        int x_map, phys_x_map;
+ *        #define set1(a) x_map = a
+ *        inline void set2(int a) { x_map = a; }
+ *        #define x_map phys_x_map
+ *        main(){ set1(3); set2(5); }
+ */
+
+extern cpumask_t cpu_possible_map;
+extern cpumask_t cpu_online_map;
+extern cpumask_t cpu_present_map;
+
+#if NR_CPUS > 1
+#define num_online_cpus()       cpus_weight(cpu_online_map)
+#define num_possible_cpus()     cpus_weight(cpu_possible_map)
+#define num_present_cpus()      cpus_weight(cpu_present_map)
+#define cpu_online(cpu)         cpu_isset((cpu), cpu_online_map)
+#define cpu_possible(cpu)       cpu_isset((cpu), cpu_possible_map)
+#define cpu_present(cpu)        cpu_isset((cpu), cpu_present_map)
+#else
+#define num_online_cpus()       1
+#define num_possible_cpus()     1
+#define num_present_cpus()      1
+#define cpu_online(cpu)         ((cpu) == 0)
+#define cpu_possible(cpu)       ((cpu) == 0)
+#define cpu_present(cpu)        ((cpu) == 0)
+#endif
+
+#define any_online_cpu(mask)                    \
+({                                              \
+        int cpu;                                \
+        for_each_cpu_mask(cpu, (mask))          \
+                if (cpu_online(cpu))            \
+                        break;                  \
+        cpu;                                    \
+})
+
+#define for_each_cpu(cpu)         for_each_cpu_mask((cpu), cpu_possible_map)
+#define for_each_online_cpu(cpu)  for_each_cpu_mask((cpu), cpu_online_map)
+#define for_each_present_cpu(cpu) for_each_cpu_mask((cpu), cpu_present_map)
+
+#endif /* __LINUX_CPUMASK_H */