1 /* $NetBSD: vmalloc.h,v 1.12 2022/02/26 15:57:22 rillig Exp $ */
2
3 /*-
4 * Copyright (c) 2013, 2018 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #ifndef _LINUX_VMALLOC_H_
33 #define _LINUX_VMALLOC_H_
34
35 #include <uvm/uvm_extern.h>
36
37 #include <linux/mm.h>
38 #include <linux/mm_types.h>
39 #include <linux/overflow.h>
40 #include <linux/slab.h>
41
42 #include <asm/page.h>
43
44 struct notifier_block;
45
46 /*
47 * XXX vmalloc and kvmalloc both use kmalloc. If you change that, be
48 * sure to update this so kvfree in <linux/mm.h> still works on vmalloc
49 * addresses.
50 */
51
52 static inline bool
is_vmalloc_addr(void * addr)53 is_vmalloc_addr(void *addr)
54 {
55 return true;
56 }
57
58 static inline void *
vmalloc(unsigned long size)59 vmalloc(unsigned long size)
60 {
61 return kmalloc(size, GFP_KERNEL);
62 }
63
64 static inline void *
vmalloc_user(unsigned long size)65 vmalloc_user(unsigned long size)
66 {
67 return kzalloc(size, GFP_KERNEL);
68 }
69
70 static inline void *
vzalloc(unsigned long size)71 vzalloc(unsigned long size)
72 {
73 return kzalloc(size, GFP_KERNEL);
74 }
75
76 static inline void
vfree(void * ptr)77 vfree(void *ptr)
78 {
79 kfree(ptr);
80 }
81
82 #define PAGE_KERNEL UVM_PROT_RW
83
84 /*
85 * vmap(pages, npages, flags, prot)
86 *
87 * Map pages[0], pages[1], ..., pages[npages-1] into contiguous
88 * kernel virtual address space with the specified protection, and
89 * return a KVA pointer to the start.
90 *
91 * prot may be a bitwise ior of UVM_PROT_READ/WRITE/EXEC and
92 * PMAP_* cache flags accepted by pmap_enter().
93 */
94 static inline void *
vmap(struct page ** pages,unsigned npages,unsigned long flags,pgprot_t protflags)95 vmap(struct page **pages, unsigned npages, unsigned long flags,
96 pgprot_t protflags)
97 {
98 vm_prot_t justprot = protflags & UVM_PROT_ALL;
99 vaddr_t va;
100 unsigned i;
101
102 /* Allocate some KVA, or return NULL if we can't. */
103 va = uvm_km_alloc(kernel_map, (vsize_t)npages << PAGE_SHIFT, PAGE_SIZE,
104 UVM_KMF_VAONLY|UVM_KMF_NOWAIT);
105 if (va == 0)
106 return NULL;
107
108 /* Ask pmap to map the KVA to the specified page addresses. */
109 for (i = 0; i < npages; i++) {
110 pmap_kenter_pa(va + i*PAGE_SIZE, page_to_phys(pages[i]),
111 justprot, protflags);
112 }
113
114 /* Commit the pmap updates. */
115 pmap_update(pmap_kernel());
116
117 return (void *)va;
118 }
119
120 /*
121 * vunmap(ptr, npages)
122 *
123 * Unmap the KVA pages starting at ptr that were mapped by a call
124 * to vmap with the same npages parameter.
125 */
126 static inline void
vunmap(void * ptr,unsigned npages)127 vunmap(void *ptr, unsigned npages)
128 {
129 vaddr_t va = (vaddr_t)ptr;
130
131 /* Ask pmap to unmap the KVA. */
132 pmap_kremove(va, (vsize_t)npages << PAGE_SHIFT);
133
134 /* Commit the pmap updates. */
135 pmap_update(pmap_kernel());
136
137 /*
138 * Now that the pmap is no longer mapping the KVA we allocated
139 * on any CPU, it is safe to free the KVA.
140 */
141 uvm_km_free(kernel_map, va, (vsize_t)npages << PAGE_SHIFT,
142 UVM_KMF_VAONLY);
143 }
144
145 static inline int
register_vmap_purge_notifier(struct notifier_block * nb __unused)146 register_vmap_purge_notifier(struct notifier_block *nb __unused)
147 {
148 return 0;
149 }
150
151 static inline int
unregister_vmap_purge_notifier(struct notifier_block * nb __unused)152 unregister_vmap_purge_notifier(struct notifier_block *nb __unused)
153 {
154 return 0;
155 }
156
157 #endif /* _LINUX_VMALLOC_H_ */
158