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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
bbeae5b0 PZ |
2 | #ifndef PAGE_FLAGS_LAYOUT_H |
3 | #define PAGE_FLAGS_LAYOUT_H | |
4 | ||
5 | #include <linux/numa.h> | |
6 | #include <generated/bounds.h> | |
7 | ||
8 | /* | |
9 | * When a memory allocation must conform to specific limitations (such | |
10 | * as being suitable for DMA) the caller will pass in hints to the | |
11 | * allocator in the gfp_mask, in the zone modifier bits. These bits | |
12 | * are used to select a priority ordered list of memory zones which | |
13 | * match the requested limits. See gfp_zone() in include/linux/gfp.h | |
14 | */ | |
15 | #if MAX_NR_ZONES < 2 | |
16 | #define ZONES_SHIFT 0 | |
17 | #elif MAX_NR_ZONES <= 2 | |
18 | #define ZONES_SHIFT 1 | |
19 | #elif MAX_NR_ZONES <= 4 | |
20 | #define ZONES_SHIFT 2 | |
b11a7b94 DW |
21 | #elif MAX_NR_ZONES <= 8 |
22 | #define ZONES_SHIFT 3 | |
bbeae5b0 | 23 | #else |
1587db62 | 24 | #error ZONES_SHIFT "Too many zones configured" |
bbeae5b0 PZ |
25 | #endif |
26 | ||
1587db62 YZ |
27 | #define ZONES_WIDTH ZONES_SHIFT |
28 | ||
bbeae5b0 PZ |
29 | #ifdef CONFIG_SPARSEMEM |
30 | #include <asm/sparsemem.h> | |
bbeae5b0 | 31 | #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS) |
1587db62 YZ |
32 | #else |
33 | #define SECTIONS_SHIFT 0 | |
34 | #endif | |
bbeae5b0 | 35 | |
ee38d94a | 36 | #ifndef BUILD_VDSO32_64 |
bbeae5b0 PZ |
37 | /* |
38 | * page->flags layout: | |
39 | * | |
75980e97 PZ |
40 | * There are five possibilities for how page->flags get laid out. The first |
41 | * pair is for the normal case without sparsemem. The second pair is for | |
42 | * sparsemem when there is plenty of space for node and section information. | |
43 | * The last is when there is insufficient space in page->flags and a separate | |
44 | * lookup is necessary. | |
bbeae5b0 | 45 | * |
b795854b | 46 | * No sparsemem or sparsemem vmemmap: | NODE | ZONE | ... | FLAGS | |
90572890 | 47 | * " plus space for last_cpupid: | NODE | ZONE | LAST_CPUPID ... | FLAGS | |
b795854b | 48 | * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS | |
90572890 | 49 | * " plus space for last_cpupid: | SECTION | NODE | ZONE | LAST_CPUPID ... | FLAGS | |
bbeae5b0 PZ |
50 | * classic sparse no space for node: | SECTION | ZONE | ... | FLAGS | |
51 | */ | |
52 | #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP) | |
53 | #define SECTIONS_WIDTH SECTIONS_SHIFT | |
54 | #else | |
55 | #define SECTIONS_WIDTH 0 | |
56 | #endif | |
57 | ||
1587db62 | 58 | #if ZONES_WIDTH + SECTIONS_WIDTH + NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS |
bbeae5b0 | 59 | #define NODES_WIDTH NODES_SHIFT |
1587db62 | 60 | #elif defined(CONFIG_SPARSEMEM_VMEMMAP) |
bbeae5b0 | 61 | #error "Vmemmap: No space for nodes field in page flags" |
1587db62 | 62 | #else |
bbeae5b0 PZ |
63 | #define NODES_WIDTH 0 |
64 | #endif | |
65 | ||
1587db62 YZ |
66 | /* |
67 | * Note that this #define MUST have a value so that it can be tested with | |
68 | * the IS_ENABLED() macro. | |
69 | */ | |
70 | #if NODES_SHIFT != 0 && NODES_WIDTH == 0 | |
71 | #define NODE_NOT_IN_PAGE_FLAGS 1 | |
72 | #endif | |
73 | ||
74 | #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) | |
75 | #define KASAN_TAG_WIDTH 8 | |
76 | #else | |
77 | #define KASAN_TAG_WIDTH 0 | |
78 | #endif | |
79 | ||
75980e97 | 80 | #ifdef CONFIG_NUMA_BALANCING |
b795854b MG |
81 | #define LAST__PID_SHIFT 8 |
82 | #define LAST__PID_MASK ((1 << LAST__PID_SHIFT)-1) | |
83 | ||
90572890 PZ |
84 | #define LAST__CPU_SHIFT NR_CPUS_BITS |
85 | #define LAST__CPU_MASK ((1 << LAST__CPU_SHIFT)-1) | |
b795854b | 86 | |
90572890 | 87 | #define LAST_CPUPID_SHIFT (LAST__PID_SHIFT+LAST__CPU_SHIFT) |
75980e97 | 88 | #else |
90572890 | 89 | #define LAST_CPUPID_SHIFT 0 |
75980e97 PZ |
90 | #endif |
91 | ||
1587db62 | 92 | #if ZONES_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + KASAN_TAG_WIDTH + LAST_CPUPID_SHIFT \ |
ee38d94a | 93 | <= BITS_PER_LONG - NR_PAGEFLAGS |
90572890 | 94 | #define LAST_CPUPID_WIDTH LAST_CPUPID_SHIFT |
75980e97 | 95 | #else |
90572890 | 96 | #define LAST_CPUPID_WIDTH 0 |
75980e97 PZ |
97 | #endif |
98 | ||
1587db62 YZ |
99 | #if LAST_CPUPID_SHIFT != 0 && LAST_CPUPID_WIDTH == 0 |
100 | #define LAST_CPUPID_NOT_IN_PAGE_FLAGS | |
bbeae5b0 PZ |
101 | #endif |
102 | ||
1587db62 YZ |
103 | #if ZONES_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + KASAN_TAG_WIDTH + LAST_CPUPID_WIDTH \ |
104 | > BITS_PER_LONG - NR_PAGEFLAGS | |
105 | #error "Not enough bits in page flags" | |
75980e97 PZ |
106 | #endif |
107 | ||
ee38d94a | 108 | #endif |
bbeae5b0 | 109 | #endif /* _LINUX_PAGE_FLAGS_LAYOUT */ |