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Commit | Line | Data |
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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 | } |