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 | ||
931641c6 | 37 | static inline int cmma_test_essa(void) |
45e576b1 MS |
38 | { |
39 | register unsigned long tmp asm("0") = 0; | |
40 | register int rc asm("1") = -EOPNOTSUPP; | |
41 | ||
45e576b1 MS |
42 | asm volatile( |
43 | " .insn rrf,0xb9ab0000,%1,%1,0,0\n" | |
44 | "0: la %0,0\n" | |
45 | "1:\n" | |
46 | EX_TABLE(0b,1b) | |
47 | : "+&d" (rc), "+&d" (tmp)); | |
931641c6 HC |
48 | return rc; |
49 | } | |
50 | ||
51 | void __init cmma_init(void) | |
52 | { | |
53 | if (!cmma_flag) | |
54 | return; | |
55 | if (cmma_test_essa()) | |
45e576b1 MS |
56 | cmma_flag = 0; |
57 | } | |
58 | ||
846955c8 | 59 | static inline void set_page_unstable(struct page *page, int order) |
45e576b1 MS |
60 | { |
61 | int i, rc; | |
62 | ||
45e576b1 MS |
63 | for (i = 0; i < (1 << order); i++) |
64 | asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" | |
65 | : "=&d" (rc) | |
846955c8 | 66 | : "a" (page_to_phys(page + i)), |
45e576b1 MS |
67 | "i" (ESSA_SET_UNUSED)); |
68 | } | |
69 | ||
846955c8 | 70 | void arch_free_page(struct page *page, int order) |
45e576b1 | 71 | { |
45e576b1 MS |
72 | if (!cmma_flag) |
73 | return; | |
846955c8 HC |
74 | set_page_unstable(page, order); |
75 | } | |
76 | ||
77 | static inline void set_page_stable(struct page *page, int order) | |
78 | { | |
79 | int i, rc; | |
80 | ||
45e576b1 MS |
81 | for (i = 0; i < (1 << order); i++) |
82 | asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" | |
83 | : "=&d" (rc) | |
846955c8 | 84 | : "a" (page_to_phys(page + i)), |
45e576b1 MS |
85 | "i" (ESSA_SET_STABLE)); |
86 | } | |
846955c8 HC |
87 | |
88 | void arch_alloc_page(struct page *page, int order) | |
89 | { | |
90 | if (!cmma_flag) | |
91 | return; | |
92 | set_page_stable(page, order); | |
93 | } | |
94 | ||
95 | void arch_set_page_states(int make_stable) | |
96 | { | |
97 | unsigned long flags, order, t; | |
98 | struct list_head *l; | |
99 | struct page *page; | |
100 | struct zone *zone; | |
101 | ||
102 | if (!cmma_flag) | |
103 | return; | |
104 | if (make_stable) | |
105 | drain_local_pages(NULL); | |
106 | for_each_populated_zone(zone) { | |
107 | spin_lock_irqsave(&zone->lock, flags); | |
108 | for_each_migratetype_order(order, t) { | |
109 | list_for_each(l, &zone->free_area[order].free_list[t]) { | |
110 | page = list_entry(l, struct page, lru); | |
111 | if (make_stable) | |
112 | set_page_stable(page, order); | |
113 | else | |
114 | set_page_unstable(page, order); | |
115 | } | |
116 | } | |
117 | spin_unlock_irqrestore(&zone->lock, flags); | |
118 | } | |
119 | } |