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1 | // SPDX-License-Identifier: GPL-2.0 |
2 | ||
3 | /****************************************************************************** | |
4 | * Xen memory reservation utilities. | |
5 | * | |
6 | * Copyright (c) 2003, B Dragovic | |
7 | * Copyright (c) 2003-2004, M Williamson, K Fraser | |
8 | * Copyright (c) 2005 Dan M. Smith, IBM Corporation | |
9 | * Copyright (c) 2010 Daniel Kiper | |
10 | * Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc. | |
11 | */ | |
12 | ||
13 | #include <asm/xen/hypercall.h> | |
14 | ||
15 | #include <xen/interface/memory.h> | |
16 | #include <xen/mem-reservation.h> | |
197ecb38 MMG |
17 | #include <linux/moduleparam.h> |
18 | ||
19 | bool __read_mostly xen_scrub_pages = IS_ENABLED(CONFIG_XEN_SCRUB_PAGES_DEFAULT); | |
20 | core_param(xen_scrub_pages, xen_scrub_pages, bool, 0); | |
ae4c51a5 OA |
21 | |
22 | /* | |
23 | * Use one extent per PAGE_SIZE to avoid to break down the page into | |
24 | * multiple frame. | |
25 | */ | |
26 | #define EXTENT_ORDER (fls(XEN_PFN_PER_PAGE) - 1) | |
27 | ||
28 | #ifdef CONFIG_XEN_HAVE_PVMMU | |
29 | void __xenmem_reservation_va_mapping_update(unsigned long count, | |
30 | struct page **pages, | |
31 | xen_pfn_t *frames) | |
32 | { | |
33 | int i; | |
34 | ||
35 | for (i = 0; i < count; i++) { | |
36 | struct page *page = pages[i]; | |
37 | unsigned long pfn = page_to_pfn(page); | |
38 | ||
39 | BUG_ON(!page); | |
40 | ||
41 | /* | |
42 | * We don't support PV MMU when Linux and Xen is using | |
43 | * different page granularity. | |
44 | */ | |
45 | BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE); | |
46 | ||
47 | set_phys_to_machine(pfn, frames[i]); | |
48 | ||
49 | /* Link back into the page tables if not highmem. */ | |
50 | if (!PageHighMem(page)) { | |
51 | int ret; | |
52 | ||
53 | ret = HYPERVISOR_update_va_mapping( | |
54 | (unsigned long)__va(pfn << PAGE_SHIFT), | |
55 | mfn_pte(frames[i], PAGE_KERNEL), | |
56 | 0); | |
57 | BUG_ON(ret); | |
58 | } | |
59 | } | |
60 | } | |
61 | EXPORT_SYMBOL_GPL(__xenmem_reservation_va_mapping_update); | |
62 | ||
63 | void __xenmem_reservation_va_mapping_reset(unsigned long count, | |
64 | struct page **pages) | |
65 | { | |
66 | int i; | |
67 | ||
68 | for (i = 0; i < count; i++) { | |
69 | struct page *page = pages[i]; | |
70 | unsigned long pfn = page_to_pfn(page); | |
71 | ||
72 | /* | |
73 | * We don't support PV MMU when Linux and Xen are using | |
74 | * different page granularity. | |
75 | */ | |
76 | BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE); | |
77 | ||
78 | if (!PageHighMem(page)) { | |
79 | int ret; | |
80 | ||
81 | ret = HYPERVISOR_update_va_mapping( | |
82 | (unsigned long)__va(pfn << PAGE_SHIFT), | |
83 | __pte_ma(0), 0); | |
84 | BUG_ON(ret); | |
85 | } | |
86 | __set_phys_to_machine(pfn, INVALID_P2M_ENTRY); | |
87 | } | |
88 | } | |
89 | EXPORT_SYMBOL_GPL(__xenmem_reservation_va_mapping_reset); | |
90 | #endif /* CONFIG_XEN_HAVE_PVMMU */ | |
91 | ||
92 | /* @frames is an array of PFNs */ | |
93 | int xenmem_reservation_increase(int count, xen_pfn_t *frames) | |
94 | { | |
95 | struct xen_memory_reservation reservation = { | |
96 | .address_bits = 0, | |
97 | .extent_order = EXTENT_ORDER, | |
98 | .domid = DOMID_SELF | |
99 | }; | |
100 | ||
101 | /* XENMEM_populate_physmap requires a PFN based on Xen granularity. */ | |
102 | set_xen_guest_handle(reservation.extent_start, frames); | |
103 | reservation.nr_extents = count; | |
104 | return HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation); | |
105 | } | |
106 | EXPORT_SYMBOL_GPL(xenmem_reservation_increase); | |
107 | ||
108 | /* @frames is an array of GFNs */ | |
109 | int xenmem_reservation_decrease(int count, xen_pfn_t *frames) | |
110 | { | |
111 | struct xen_memory_reservation reservation = { | |
112 | .address_bits = 0, | |
113 | .extent_order = EXTENT_ORDER, | |
114 | .domid = DOMID_SELF | |
115 | }; | |
116 | ||
117 | /* XENMEM_decrease_reservation requires a GFN */ | |
118 | set_xen_guest_handle(reservation.extent_start, frames); | |
119 | reservation.nr_extents = count; | |
120 | return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); | |
121 | } | |
122 | EXPORT_SYMBOL_GPL(xenmem_reservation_decrease); |