projects / linux-block.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> | |
| 13 | #include <linux/init.h> | |
| 14 | ||
| 15 | #define ESSA_SET_STABLE 1 | |
| 16 | #define ESSA_SET_UNUSED 2 | |
| 17 | ||
| 2ddddf3e | 18 | static int cmma_flag = 1; |
| 45e576b1 MS |
19 | |
| 20 | static int __init cmma(char *str) | |
| 21 | { | |
| 22 | char *parm; | |
| 2ddddf3e | 23 | |
| 45e576b1 MS |
24 | parm = strstrip(str); |
| 25 | if (strcmp(parm, "yes") == 0 || strcmp(parm, "on") == 0) { | |
| 26 | cmma_flag = 1; | |
| 27 | return 1; | |
| 28 | } | |
| 29 | cmma_flag = 0; | |
| 30 | if (strcmp(parm, "no") == 0 || strcmp(parm, "off") == 0) | |
| 31 | return 1; | |
| 32 | return 0; | |
| 33 | } | |
| 45e576b1 MS |
34 | __setup("cmma=", cmma); |
| 35 | ||
| 36 | void __init cmma_init(void) | |
| 37 | { | |
| 38 | register unsigned long tmp asm("0") = 0; | |
| 39 | register int rc asm("1") = -EOPNOTSUPP; | |
| 40 | ||
| 41 | if (!cmma_flag) | |
| 42 | return; | |
| 43 | asm volatile( | |
| 44 | " .insn rrf,0xb9ab0000,%1,%1,0,0\n" | |
| 45 | "0: la %0,0\n" | |
| 46 | "1:\n" | |
| 47 | EX_TABLE(0b,1b) | |
| 48 | : "+&d" (rc), "+&d" (tmp)); | |
| 49 | if (rc) | |
| 50 | cmma_flag = 0; | |
| 51 | } | |
| 52 | ||
| 53 | void arch_free_page(struct page *page, int order) | |
| 54 | { | |
| 55 | int i, rc; | |
| 56 | ||
| 57 | if (!cmma_flag) | |
| 58 | return; | |
| 59 | for (i = 0; i < (1 << order); i++) | |
| 60 | asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" | |
| 61 | : "=&d" (rc) | |
| 62 | : "a" ((page_to_pfn(page) + i) << PAGE_SHIFT), | |
| 63 | "i" (ESSA_SET_UNUSED)); | |
| 64 | } | |
| 65 | ||
| 66 | void arch_alloc_page(struct page *page, int order) | |
| 67 | { | |
| 68 | int i, rc; | |
| 69 | ||
| 70 | if (!cmma_flag) | |
| 71 | return; | |
| 72 | for (i = 0; i < (1 << order); i++) | |
| 73 | asm volatile(".insn rrf,0xb9ab0000,%0,%1,%2,0" | |
| 74 | : "=&d" (rc) | |
| 75 | : "a" ((page_to_pfn(page) + i) << PAGE_SHIFT), | |
| 76 | "i" (ESSA_SET_STABLE)); | |
| 77 | } |