projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 45e576b1 | 1 | /* |
| 45e576b1 MS |
2 | * Copyright IBM Corp. 2008 |
| 3 | * | |
| 4 | * Guest page hinting for unused pages. | |
| 5 | * | |
| 6 | * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> | |
| 7 | */ | |
| 8 | ||
| 9 | #include <linux/kernel.h> | |
| 10 | #include <linux/errno.h> | |
| 11 | #include <linux/types.h> | |
| 12 | #include <linux/mm.h> | |
| 5a0e3ad6 | 13 | #include <linux/gfp.h> |
| 45e576b1 MS |
14 | #include <linux/init.h> |
| 15 | ||
| 16 | #define ESSA_SET_STABLE 1 | |
| 17 | #define ESSA_SET_UNUSED 2 | |
| 18 | ||
| 2ddddf3e | 19 | static int cmma_flag = 1; |
| 45e576b1 MS |
20 | |
| 21 | static int __init cmma(char *str) | |
| 22 | { | |
| 23 | char *parm; | |
| 2ddddf3e | 24 | |
| 45e576b1 MS |
25 | parm = strstrip(str); |
| 26 | if (strcmp(parm, "yes") == 0 || strcmp(parm, "on") == 0) { | |
| 27 | cmma_flag = 1; | |
| 28 | return 1; | |
| 29 | } | |
| 30 | cmma_flag = 0; | |
| 31 | if (strcmp(parm, "no") == 0 || strcmp(parm, "off") == 0) | |
| 32 | return 1; | |
| 33 | return 0; | |
| 34 | } | |
| 45e576b1 MS |
35 | __setup("cmma=", cmma); |
| 36 | ||
| 37 | void __init cmma_init(void) | |
| 38 | { | |
| 39 | register unsigned long tmp asm("0") = 0; | |
| 40 | register int rc asm("1") = -EOPNOTSUPP; | |
| 41 | ||
| 42 | if (!cmma_flag) | |
| 43 | return; | |
| 44 | asm volatile( | |
| 45 | " .insn rrf,0xb9ab0000,%1,%1,0,0\n" | |
| 46 | "0: la %0,0\n" | |
| 47 | "1:\n" | |
| 48 | EX_TABLE(0b,1b) | |
| 49 | : "+&d" (rc), "+&d" (tmp)); | |
| 50 | if (rc) | |
| 51 | cmma_flag = 0; | |
| 52 | } | |
| 53 | ||
| 846955c8 | 54 | static inline void set_page_unstable(struct page *page, int order) |
| 45e576b1 MS |
55 | { |
| 56 | int i, rc; | |
| 57 | ||
| 45e576b1 MS |
58 | for (i = 0; i < (1 << order); i++) |
| 59 | asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" | |
| 60 | : "=&d" (rc) | |
| 846955c8 | 61 | : "a" (page_to_phys(page + i)), |
| 45e576b1 MS |
62 | "i" (ESSA_SET_UNUSED)); |
| 63 | } | |
| 64 | ||
| 846955c8 | 65 | void arch_free_page(struct page *page, int order) |
| 45e576b1 | 66 | { |
| 45e576b1 MS |
67 | if (!cmma_flag) |
| 68 | return; | |
| 846955c8 HC |
69 | set_page_unstable(page, order); |
| 70 | } | |
| 71 | ||
| 72 | static inline void set_page_stable(struct page *page, int order) | |
| 73 | { | |
| 74 | int i, rc; | |
| 75 | ||
| 45e576b1 MS |
76 | for (i = 0; i < (1 << order); i++) |
| 77 | asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" | |
| 78 | : "=&d" (rc) | |
| 846955c8 | 79 | : "a" (page_to_phys(page + i)), |
| 45e576b1 MS |
80 | "i" (ESSA_SET_STABLE)); |
| 81 | } | |
| 846955c8 HC |
82 | |
| 83 | void arch_alloc_page(struct page *page, int order) | |
| 84 | { | |
| 85 | if (!cmma_flag) | |
| 86 | return; | |
| 87 | set_page_stable(page, order); | |
| 88 | } | |
| 89 | ||
| 90 | void arch_set_page_states(int make_stable) | |
| 91 | { | |
| 92 | unsigned long flags, order, t; | |
| 93 | struct list_head *l; | |
| 94 | struct page *page; | |
| 95 | struct zone *zone; | |
| 96 | ||
| 97 | if (!cmma_flag) | |
| 98 | return; | |
| 99 | if (make_stable) | |
| 100 | drain_local_pages(NULL); | |
| 101 | for_each_populated_zone(zone) { | |
| 102 | spin_lock_irqsave(&zone->lock, flags); | |
| 103 | for_each_migratetype_order(order, t) { | |
| 104 | list_for_each(l, &zone->free_area[order].free_list[t]) { | |
| 105 | page = list_entry(l, struct page, lru); | |
| 106 | if (make_stable) | |
| 107 | set_page_stable(page, order); | |
| 108 | else | |
| 109 | set_page_unstable(page, order); | |
| 110 | } | |
| 111 | } | |
| 112 | spin_unlock_irqrestore(&zone->lock, flags); | |
| 113 | } | |
| 114 | } |