Commit | Line | Data |
---|---|---|
306b0c95 | 1 | /* |
f1e3cfff | 2 | * Compressed RAM block device |
306b0c95 | 3 | * |
1130ebba | 4 | * Copyright (C) 2008, 2009, 2010 Nitin Gupta |
7bfb3de8 | 5 | * 2012, 2013 Minchan Kim |
306b0c95 NG |
6 | * |
7 | * This code is released using a dual license strategy: BSD/GPL | |
8 | * You can choose the licence that better fits your requirements. | |
9 | * | |
10 | * Released under the terms of 3-clause BSD License | |
11 | * Released under the terms of GNU General Public License Version 2.0 | |
12 | * | |
306b0c95 NG |
13 | */ |
14 | ||
f1e3cfff NG |
15 | #ifndef _ZRAM_DRV_H_ |
16 | #define _ZRAM_DRV_H_ | |
306b0c95 | 17 | |
415403be | 18 | #include <linux/rwsem.h> |
bcf1647d | 19 | #include <linux/zsmalloc.h> |
415403be | 20 | #include <linux/crypto.h> |
306b0c95 | 21 | |
b7ca232e SS |
22 | #include "zcomp.h" |
23 | ||
306b0c95 NG |
24 | #define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) |
25 | #define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT) | |
924bd88d JM |
26 | #define ZRAM_LOGICAL_BLOCK_SHIFT 12 |
27 | #define ZRAM_LOGICAL_BLOCK_SIZE (1 << ZRAM_LOGICAL_BLOCK_SHIFT) | |
28 | #define ZRAM_SECTOR_PER_LOGICAL_BLOCK \ | |
29 | (1 << (ZRAM_LOGICAL_BLOCK_SHIFT - SECTOR_SHIFT)) | |
306b0c95 | 30 | |
d2d5e762 WY |
31 | |
32 | /* | |
f635725c SS |
33 | * ZRAM is mainly used for memory efficiency so we want to keep memory |
34 | * footprint small and thus squeeze size and zram pageflags into a flags | |
35 | * member. The lower ZRAM_FLAG_SHIFT bits is for object size (excluding | |
36 | * header), which cannot be larger than PAGE_SIZE (requiring PAGE_SHIFT | |
37 | * bits), the higher bits are for zram_pageflags. | |
d2d5e762 | 38 | * |
f635725c | 39 | * We use BUILD_BUG_ON() to make sure that zram pageflags don't overflow. |
d2d5e762 | 40 | */ |
f635725c | 41 | #define ZRAM_FLAG_SHIFT (PAGE_SHIFT + 1) |
d2d5e762 | 42 | |
84b33bf7 SS |
43 | /* Only 2 bits are allowed for comp priority index */ |
44 | #define ZRAM_COMP_PRIORITY_MASK 0x3 | |
45 | ||
7e529283 | 46 | /* Flags for zram pages (table[page_no].flags) */ |
f1e3cfff | 47 | enum zram_pageflags { |
6086aeb4 | 48 | ZRAM_SAME = ZRAM_FLAG_SHIFT, /* Page consists the same element */ |
db8ffbd4 | 49 | ZRAM_WB, /* page is stored on backing_device */ |
a939888e | 50 | ZRAM_UNDER_WB, /* page is under writeback */ |
89e85bce | 51 | ZRAM_HUGE, /* Incompressible page */ |
e82592c4 | 52 | ZRAM_IDLE, /* not accessed page since last idle marking */ |
84b33bf7 SS |
53 | ZRAM_INCOMPRESSIBLE, /* none of the algorithms could compress it */ |
54 | ||
55 | ZRAM_COMP_PRIORITY_BIT1, /* First bit of comp priority index */ | |
56 | ZRAM_COMP_PRIORITY_BIT2, /* Second bit of comp priority index */ | |
306b0c95 | 57 | |
f1e3cfff | 58 | __NR_ZRAM_PAGEFLAGS, |
306b0c95 NG |
59 | }; |
60 | ||
61 | /*-- Data structures */ | |
62 | ||
f1e3cfff | 63 | /* Allocated for each disk page */ |
cb8f2eec | 64 | struct zram_table_entry { |
8e19d540 | 65 | union { |
66 | unsigned long handle; | |
67 | unsigned long element; | |
68 | }; | |
68d20eb6 | 69 | unsigned int flags; |
9518e5bf | 70 | spinlock_t lock; |
a7a03505 | 71 | #ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME |
c0265342 MK |
72 | ktime_t ac_time; |
73 | #endif | |
d2d5e762 | 74 | }; |
306b0c95 | 75 | |
f1e3cfff | 76 | struct zram_stats { |
90a7806e | 77 | atomic64_t compr_data_size; /* compressed size of pages stored */ |
0cf1e9d6 | 78 | atomic64_t failed_reads; /* can happen when memory is too low */ |
da5cc7d3 | 79 | atomic64_t failed_writes; /* can happen when memory is too low */ |
da5cc7d3 | 80 | atomic64_t notify_free; /* no. of swap slot free notifications */ |
8e19d540 | 81 | atomic64_t same_pages; /* no. of same element filled pages */ |
89e85bce | 82 | atomic64_t huge_pages; /* no. of huge pages */ |
194e28da | 83 | atomic64_t huge_pages_since; /* no. of huge pages since zram set up */ |
90a7806e | 84 | atomic64_t pages_stored; /* no. of pages currently stored */ |
461a8eee | 85 | atomic_long_t max_used_pages; /* no. of maximum pages stored */ |
37887783 | 86 | atomic64_t writestall; /* no. of write slow paths */ |
3c9959e0 | 87 | atomic64_t miss_free; /* no. of missed free */ |
23eddf39 MK |
88 | #ifdef CONFIG_ZRAM_WRITEBACK |
89 | atomic64_t bd_count; /* no. of pages in backing device */ | |
90 | atomic64_t bd_reads; /* no. of reads from backing device */ | |
91 | atomic64_t bd_writes; /* no. of writes from backing device */ | |
92 | #endif | |
306b0c95 NG |
93 | }; |
94 | ||
7ac07a26 SS |
95 | #ifdef CONFIG_ZRAM_MULTI_COMP |
96 | #define ZRAM_PRIMARY_COMP 0U | |
97 | #define ZRAM_SECONDARY_COMP 1U | |
98 | #define ZRAM_MAX_COMPS 4U | |
99 | #else | |
100 | #define ZRAM_PRIMARY_COMP 0U | |
101 | #define ZRAM_SECONDARY_COMP 0U | |
102 | #define ZRAM_MAX_COMPS 1U | |
103 | #endif | |
104 | ||
beb6602c | 105 | struct zram { |
cb8f2eec | 106 | struct zram_table_entry *table; |
8b3cc3ed | 107 | struct zs_pool *mem_pool; |
7ac07a26 | 108 | struct zcomp *comps[ZRAM_MAX_COMPS]; |
f2bac7ad | 109 | struct zcomp_params params[ZRAM_MAX_COMPS]; |
306b0c95 | 110 | struct gendisk *disk; |
08eee69f | 111 | /* Prevent concurrent execution of device init */ |
0900beae | 112 | struct rw_semaphore init_lock; |
306b0c95 | 113 | /* |
08eee69f | 114 | * the number of pages zram can consume for storing compressed data |
306b0c95 | 115 | */ |
08eee69f | 116 | unsigned long limit_pages; |
08eee69f | 117 | |
f1e3cfff | 118 | struct zram_stats stats; |
9ada9da9 | 119 | /* |
08eee69f MK |
120 | * This is the limit on amount of *uncompressed* worth of data |
121 | * we can store in a disk. | |
9ada9da9 | 122 | */ |
08eee69f | 123 | u64 disksize; /* bytes */ |
7ac07a26 | 124 | const char *comp_algs[ZRAM_MAX_COMPS]; |
a55cf964 | 125 | s8 num_active_comps; |
f405c445 SS |
126 | /* |
127 | * zram is claimed so open request will be failed | |
128 | */ | |
a8698707 | 129 | bool claim; /* Protected by disk->open_mutex */ |
7e529283 | 130 | #ifdef CONFIG_ZRAM_WRITEBACK |
dd794835 | 131 | struct file *backing_dev; |
1d69a3f8 MK |
132 | spinlock_t wb_limit_lock; |
133 | bool wb_limit_enable; | |
134 | u64 bd_wb_limit; | |
ebb0173d | 135 | struct block_device *bdev; |
1363d466 MK |
136 | unsigned long *bitmap; |
137 | unsigned long nr_pages; | |
013bf95a | 138 | #endif |
c0265342 MK |
139 | #ifdef CONFIG_ZRAM_MEMORY_TRACKING |
140 | struct dentry *debugfs_dir; | |
141 | #endif | |
306b0c95 | 142 | }; |
6a907728 | 143 | #endif |