| 1 | #ifndef _FLEX_ARRAY_H
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| 2 | #define _FLEX_ARRAY_H
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| 3 |
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| 4 | #include <linux/types.h>
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| 5 | #include <asm/page.h>
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| 6 |
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| 7 | #define FLEX_ARRAY_PART_SIZE PAGE_SIZE
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| 8 | #define FLEX_ARRAY_BASE_SIZE PAGE_SIZE
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| 9 |
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| 10 | struct flex_array_part;
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| 11 |
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| 12 | |
| 13 | * This is meant to replace cases where an array-like
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| 14 | * structure has gotten too big to fit into kmalloc()
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| 15 | * and the developer is getting tempted to use
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| 16 | * vmalloc().
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| 17 |
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| 18 |
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| 19 | struct flex_array {
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| 20 | union {
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| 21 | struct {
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| 22 | int element_size;
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| 23 | int total_nr_elements;
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| 24 | struct flex_array_part *parts[];
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| 25 | };
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| 26 | |
| 27 | * This little trick makes sure that
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| 28 | * sizeof(flex_array) == PAGE_SIZE
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| 29 |
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| 30 | char padding[FLEX_ARRAY_BASE_SIZE];
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| 31 | };
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| 32 | };
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| 33 |
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| 34 | #define FLEX_ARRAY_INIT(size, total) { { {\
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| 35 | .element_size = (size), \
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| 36 | .total_nr_elements = (total), \
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| 37 | } } }
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| 38 |
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| 39 | struct flex_array *flex_array_alloc(int element_size, unsigned int total,
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| 40 | gfp_t flags);
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| 41 | int flex_array_prealloc(struct flex_array *fa, unsigned int start,
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| 42 | unsigned int end, gfp_t flags);
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| 43 | void flex_array_free(struct flex_array *fa);
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| 44 | void flex_array_free_parts(struct flex_array *fa);
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| 45 | int flex_array_put(struct flex_array *fa, unsigned int element_nr, void *src,
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| 46 | gfp_t flags);
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| 47 | int flex_array_clear(struct flex_array *fa, unsigned int element_nr);
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| 48 | void *flex_array_get(struct flex_array *fa, unsigned int element_nr);
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| 49 | int flex_array_shrink(struct flex_array *fa);
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| 50 |
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| 51 | #endif
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