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-rw-r--r--include/linux/cpumask.h264
1 files changed, 163 insertions, 101 deletions
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index fe29ac7cc469..bd047864c7ac 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -12,6 +12,8 @@
#include <linux/bitmap.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;
@@ -116,85 +118,6 @@ static __always_inline unsigned int cpumask_check(unsigned int cpu)
return cpu;
}
-#if NR_CPUS == 1
-/* Uniprocessor. Assume all masks are "1". */
-static inline unsigned int cpumask_first(const struct cpumask *srcp)
-{
- return 0;
-}
-
-static inline unsigned int cpumask_first_zero(const struct cpumask *srcp)
-{
- return 0;
-}
-
-static inline unsigned int cpumask_first_and(const struct cpumask *srcp1,
- const struct cpumask *srcp2)
-{
- return 0;
-}
-
-static inline unsigned int cpumask_last(const struct cpumask *srcp)
-{
- return 0;
-}
-
-/* Valid inputs for n are -1 and 0. */
-static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
-{
- return n+1;
-}
-
-static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
-{
- return n+1;
-}
-
-static inline unsigned int cpumask_next_and(int n,
- const struct cpumask *srcp,
- const struct cpumask *andp)
-{
- return n+1;
-}
-
-static inline unsigned int cpumask_next_wrap(int n, const struct cpumask *mask,
- int start, bool wrap)
-{
- /* cpu0 unless stop condition, wrap and at cpu0, then nr_cpumask_bits */
- return (wrap && n == 0);
-}
-
-/* cpu must be a valid cpu, ie 0, so there's no other choice. */
-static inline unsigned int cpumask_any_but(const struct cpumask *mask,
- unsigned int cpu)
-{
- return 1;
-}
-
-static inline unsigned int cpumask_local_spread(unsigned int i, int node)
-{
- return 0;
-}
-
-static inline int cpumask_any_and_distribute(const struct cpumask *src1p,
- const struct cpumask *src2p) {
- return cpumask_first_and(src1p, src2p);
-}
-
-static inline int cpumask_any_distribute(const struct cpumask *srcp)
-{
- return cpumask_first(srcp);
-}
-
-#define for_each_cpu(cpu, mask) \
- for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
-#define for_each_cpu_not(cpu, mask) \
- for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
-#define for_each_cpu_wrap(cpu, mask, start) \
- for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)(start))
-#define for_each_cpu_and(cpu, mask1, mask2) \
- for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask1, (void)mask2)
-#else
/**
* cpumask_first - get the first cpu in a cpumask
* @srcp: the cpumask pointer
@@ -241,7 +164,21 @@ static inline unsigned int cpumask_last(const struct cpumask *srcp)
return find_last_bit(cpumask_bits(srcp), nr_cpumask_bits);
}
-unsigned int __pure cpumask_next(int n, const struct cpumask *srcp);
+/**
+ * cpumask_next - get the next cpu in a cpumask
+ * @n: the cpu prior to the place to search (ie. return will be > @n)
+ * @srcp: the cpumask pointer
+ *
+ * Returns >= nr_cpu_ids if no further cpus set.
+ */
+static inline
+unsigned int cpumask_next(int n, const struct cpumask *srcp)
+{
+ /* -1 is a legal arg here. */
+ if (n != -1)
+ cpumask_check(n);
+ return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1);
+}
/**
* cpumask_next_zero - get the next unset cpu in a cpumask
@@ -258,12 +195,48 @@ static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
}
-int __pure cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
-int __pure cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
+#if NR_CPUS == 1
+/* Uniprocessor: there is only one valid CPU */
+static inline unsigned int cpumask_local_spread(unsigned int i, int node)
+{
+ return 0;
+}
+
+static inline unsigned int cpumask_any_and_distribute(const struct cpumask *src1p,
+ const struct cpumask *src2p)
+{
+ return cpumask_first_and(src1p, src2p);
+}
+
+static inline unsigned int cpumask_any_distribute(const struct cpumask *srcp)
+{
+ return cpumask_first(srcp);
+}
+#else
unsigned int cpumask_local_spread(unsigned int i, int node);
-int cpumask_any_and_distribute(const struct cpumask *src1p,
+unsigned int cpumask_any_and_distribute(const struct cpumask *src1p,
const struct cpumask *src2p);
-int cpumask_any_distribute(const struct cpumask *srcp);
+unsigned int cpumask_any_distribute(const struct cpumask *srcp);
+#endif /* NR_CPUS */
+
+/**
+ * cpumask_next_and - get the next cpu in *src1p & *src2p
+ * @n: the cpu prior to the place to search (ie. return will be > @n)
+ * @src1p: the first cpumask pointer
+ * @src2p: the second cpumask pointer
+ *
+ * Returns >= nr_cpu_ids if no further cpus set in both.
+ */
+static inline
+unsigned int cpumask_next_and(int n, const struct cpumask *src1p,
+ const struct cpumask *src2p)
+{
+ /* -1 is a legal arg here. */
+ if (n != -1)
+ cpumask_check(n);
+ return find_next_and_bit(cpumask_bits(src1p), cpumask_bits(src2p),
+ nr_cpumask_bits, n + 1);
+}
/**
* for_each_cpu - iterate over every cpu in a mask
@@ -289,7 +262,26 @@ int cpumask_any_distribute(const struct cpumask *srcp);
(cpu) = cpumask_next_zero((cpu), (mask)), \
(cpu) < nr_cpu_ids;)
-extern int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap);
+#if NR_CPUS == 1
+static inline
+unsigned int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap)
+{
+ cpumask_check(start);
+ if (n != -1)
+ cpumask_check(n);
+
+ /*
+ * Return the first available CPU when wrapping, or when starting before cpu0,
+ * since there is only one valid option.
+ */
+ if (wrap && n >= 0)
+ return nr_cpumask_bits;
+
+ return cpumask_first(mask);
+}
+#else
+unsigned int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap);
+#endif
/**
* for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location
@@ -324,7 +316,26 @@ extern int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool
for ((cpu) = -1; \
(cpu) = cpumask_next_and((cpu), (mask1), (mask2)), \
(cpu) < nr_cpu_ids;)
-#endif /* SMP */
+
+/**
+ * cpumask_any_but - return a "random" in a cpumask, but not this one.
+ * @mask: the cpumask to search
+ * @cpu: the cpu to ignore.
+ *
+ * Often used to find any cpu but smp_processor_id() in a mask.
+ * Returns >= nr_cpu_ids if no cpus set.
+ */
+static inline
+unsigned int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
+{
+ unsigned int i;
+
+ cpumask_check(cpu);
+ for_each_cpu(i, mask)
+ if (i != cpu)
+ break;
+ return i;
+}
#define CPU_BITS_NONE \
{ \
@@ -372,9 +383,9 @@ static __always_inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp)
* @cpu: cpu number (< nr_cpu_ids)
* @cpumask: the cpumask pointer
*
- * Returns 1 if @cpu is set in @cpumask, else returns 0
+ * Returns true if @cpu is set in @cpumask, else returns false
*/
-static __always_inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask)
+static __always_inline bool cpumask_test_cpu(int cpu, const struct cpumask *cpumask)
{
return test_bit(cpumask_check(cpu), cpumask_bits((cpumask)));
}
@@ -384,11 +395,11 @@ static __always_inline int cpumask_test_cpu(int cpu, const struct cpumask *cpuma
* @cpu: cpu number (< nr_cpu_ids)
* @cpumask: the cpumask pointer
*
- * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
+ * Returns true if @cpu is set in old bitmap of @cpumask, else returns false
*
* test_and_set_bit wrapper for cpumasks.
*/
-static __always_inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
+static __always_inline bool cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
{
return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
}
@@ -398,11 +409,11 @@ static __always_inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpu
* @cpu: cpu number (< nr_cpu_ids)
* @cpumask: the cpumask pointer
*
- * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
+ * Returns true if @cpu is set in old bitmap of @cpumask, else returns false
*
* test_and_clear_bit wrapper for cpumasks.
*/
-static __always_inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
+static __always_inline bool cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
{
return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask));
}
@@ -431,9 +442,9 @@ static inline void cpumask_clear(struct cpumask *dstp)
* @src1p: the first input
* @src2p: the second input
*
- * If *@dstp is empty, returns 0, else returns 1
+ * If *@dstp is empty, returns false, else returns true
*/
-static inline int cpumask_and(struct cpumask *dstp,
+static inline bool cpumask_and(struct cpumask *dstp,
const struct cpumask *src1p,
const struct cpumask *src2p)
{
@@ -474,9 +485,9 @@ static inline void cpumask_xor(struct cpumask *dstp,
* @src1p: the first input
* @src2p: the second input
*
- * If *@dstp is empty, returns 0, else returns 1
+ * If *@dstp is empty, returns false, else returns true
*/
-static inline int cpumask_andnot(struct cpumask *dstp,
+static inline bool cpumask_andnot(struct cpumask *dstp,
const struct cpumask *src1p,
const struct cpumask *src2p)
{
@@ -539,9 +550,9 @@ static inline bool cpumask_intersects(const struct cpumask *src1p,
* @src1p: the first input
* @src2p: the second input
*
- * Returns 1 if *@src1p is a subset of *@src2p, else returns 0
+ * Returns true if *@src1p is a subset of *@src2p, else returns false
*/
-static inline int cpumask_subset(const struct cpumask *src1p,
+static inline bool cpumask_subset(const struct cpumask *src1p,
const struct cpumask *src2p)
{
return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
@@ -743,9 +754,35 @@ typedef struct cpumask *cpumask_var_t;
#define __cpumask_var_read_mostly __read_mostly
bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
-bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
-bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
-bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
+
+static inline
+bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
+{
+ return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
+}
+
+/**
+ * alloc_cpumask_var - allocate a struct cpumask
+ * @mask: pointer to cpumask_var_t where the cpumask is returned
+ * @flags: GFP_ flags
+ *
+ * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
+ * a nop returning a constant 1 (in <linux/cpumask.h>).
+ *
+ * See alloc_cpumask_var_node.
+ */
+static inline
+bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
+{
+ return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE);
+}
+
+static inline
+bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
+{
+ return alloc_cpumask_var(mask, flags | __GFP_ZERO);
+}
+
void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
void free_cpumask_var(cpumask_var_t mask);
void free_bootmem_cpumask_var(cpumask_var_t mask);
@@ -811,9 +848,16 @@ extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
/* First bits of cpu_bit_bitmap are in fact unset. */
#define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
+#if NR_CPUS == 1
+/* Uniprocessor: the possible/online/present masks are always "1" */
+#define for_each_possible_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++)
+#define for_each_online_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++)
+#define for_each_present_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++)
+#else
#define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
#define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask)
#define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask)
+#endif
/* Wrappers for arch boot code to manipulate normally-constant masks */
void init_cpu_present(const struct cpumask *src);
@@ -1071,4 +1115,22 @@ cpumap_print_list_to_buf(char *buf, const struct cpumask *mask,
[0] = 1UL \
} }
+/*
+ * Provide a valid theoretical max size for cpumap and cpulist sysfs files
+ * to avoid breaking userspace which may allocate a buffer based on the size
+ * reported by e.g. fstat.
+ *
+ * for cpumap NR_CPUS * 9/32 - 1 should be an exact length.
+ *
+ * For cpulist 7 is (ceil(log10(NR_CPUS)) + 1) allowing for NR_CPUS to be up
+ * to 2 orders of magnitude larger than 8192. And then we divide by 2 to
+ * cover a worst-case of every other cpu being on one of two nodes for a
+ * very large NR_CPUS.
+ *
+ * Use PAGE_SIZE as a minimum for smaller configurations.
+ */
+#define CPUMAP_FILE_MAX_BYTES ((((NR_CPUS * 9)/32 - 1) > PAGE_SIZE) \
+ ? (NR_CPUS * 9)/32 - 1 : PAGE_SIZE)
+#define CPULIST_FILE_MAX_BYTES (((NR_CPUS * 7)/2 > PAGE_SIZE) ? (NR_CPUS * 7)/2 : PAGE_SIZE)
+
#endif /* __LINUX_CPUMASK_H */