Merge tag '5.7-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6
[linux-2.6-microblaze.git] / kernel / dma / remap.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  * Copyright (c) 2014 The Linux Foundation
5  */
6 #include <linux/dma-direct.h>
7 #include <linux/dma-noncoherent.h>
8 #include <linux/dma-contiguous.h>
9 #include <linux/init.h>
10 #include <linux/genalloc.h>
11 #include <linux/slab.h>
12 #include <linux/vmalloc.h>
13
14 struct page **dma_common_find_pages(void *cpu_addr)
15 {
16         struct vm_struct *area = find_vm_area(cpu_addr);
17
18         if (!area || area->flags != VM_DMA_COHERENT)
19                 return NULL;
20         return area->pages;
21 }
22
23 static struct vm_struct *__dma_common_pages_remap(struct page **pages,
24                         size_t size, pgprot_t prot, const void *caller)
25 {
26         struct vm_struct *area;
27
28         area = get_vm_area_caller(size, VM_DMA_COHERENT, caller);
29         if (!area)
30                 return NULL;
31
32         if (map_vm_area(area, prot, pages)) {
33                 vunmap(area->addr);
34                 return NULL;
35         }
36
37         return area;
38 }
39
40 /*
41  * Remaps an array of PAGE_SIZE pages into another vm_area.
42  * Cannot be used in non-sleeping contexts
43  */
44 void *dma_common_pages_remap(struct page **pages, size_t size,
45                          pgprot_t prot, const void *caller)
46 {
47         struct vm_struct *area;
48
49         area = __dma_common_pages_remap(pages, size, prot, caller);
50         if (!area)
51                 return NULL;
52
53         area->pages = pages;
54
55         return area->addr;
56 }
57
58 /*
59  * Remaps an allocated contiguous region into another vm_area.
60  * Cannot be used in non-sleeping contexts
61  */
62 void *dma_common_contiguous_remap(struct page *page, size_t size,
63                         pgprot_t prot, const void *caller)
64 {
65         int i;
66         struct page **pages;
67         struct vm_struct *area;
68
69         pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
70         if (!pages)
71                 return NULL;
72
73         for (i = 0; i < (size >> PAGE_SHIFT); i++)
74                 pages[i] = nth_page(page, i);
75
76         area = __dma_common_pages_remap(pages, size, prot, caller);
77
78         kfree(pages);
79
80         if (!area)
81                 return NULL;
82         return area->addr;
83 }
84
85 /*
86  * Unmaps a range previously mapped by dma_common_*_remap
87  */
88 void dma_common_free_remap(void *cpu_addr, size_t size)
89 {
90         struct vm_struct *area = find_vm_area(cpu_addr);
91
92         if (!area || area->flags != VM_DMA_COHERENT) {
93                 WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
94                 return;
95         }
96
97         unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
98         vunmap(cpu_addr);
99 }
100
101 #ifdef CONFIG_DMA_DIRECT_REMAP
102 static struct gen_pool *atomic_pool __ro_after_init;
103
104 #define DEFAULT_DMA_COHERENT_POOL_SIZE  SZ_256K
105 static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;
106
107 static int __init early_coherent_pool(char *p)
108 {
109         atomic_pool_size = memparse(p, &p);
110         return 0;
111 }
112 early_param("coherent_pool", early_coherent_pool);
113
114 static gfp_t dma_atomic_pool_gfp(void)
115 {
116         if (IS_ENABLED(CONFIG_ZONE_DMA))
117                 return GFP_DMA;
118         if (IS_ENABLED(CONFIG_ZONE_DMA32))
119                 return GFP_DMA32;
120         return GFP_KERNEL;
121 }
122
123 static int __init dma_atomic_pool_init(void)
124 {
125         unsigned int pool_size_order = get_order(atomic_pool_size);
126         unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
127         struct page *page;
128         void *addr;
129         int ret;
130
131         if (dev_get_cma_area(NULL))
132                 page = dma_alloc_from_contiguous(NULL, nr_pages,
133                                                  pool_size_order, false);
134         else
135                 page = alloc_pages(dma_atomic_pool_gfp(), pool_size_order);
136         if (!page)
137                 goto out;
138
139         arch_dma_prep_coherent(page, atomic_pool_size);
140
141         atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
142         if (!atomic_pool)
143                 goto free_page;
144
145         addr = dma_common_contiguous_remap(page, atomic_pool_size,
146                                            pgprot_dmacoherent(PAGE_KERNEL),
147                                            __builtin_return_address(0));
148         if (!addr)
149                 goto destroy_genpool;
150
151         ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
152                                 page_to_phys(page), atomic_pool_size, -1);
153         if (ret)
154                 goto remove_mapping;
155         gen_pool_set_algo(atomic_pool, gen_pool_first_fit_order_align, NULL);
156
157         pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
158                 atomic_pool_size / 1024);
159         return 0;
160
161 remove_mapping:
162         dma_common_free_remap(addr, atomic_pool_size);
163 destroy_genpool:
164         gen_pool_destroy(atomic_pool);
165         atomic_pool = NULL;
166 free_page:
167         if (!dma_release_from_contiguous(NULL, page, nr_pages))
168                 __free_pages(page, pool_size_order);
169 out:
170         pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
171                 atomic_pool_size / 1024);
172         return -ENOMEM;
173 }
174 postcore_initcall(dma_atomic_pool_init);
175
176 bool dma_in_atomic_pool(void *start, size_t size)
177 {
178         if (unlikely(!atomic_pool))
179                 return false;
180
181         return gen_pool_has_addr(atomic_pool, (unsigned long)start, size);
182 }
183
184 void *dma_alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
185 {
186         unsigned long val;
187         void *ptr = NULL;
188
189         if (!atomic_pool) {
190                 WARN(1, "coherent pool not initialised!\n");
191                 return NULL;
192         }
193
194         val = gen_pool_alloc(atomic_pool, size);
195         if (val) {
196                 phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
197
198                 *ret_page = pfn_to_page(__phys_to_pfn(phys));
199                 ptr = (void *)val;
200                 memset(ptr, 0, size);
201         }
202
203         return ptr;
204 }
205
206 bool dma_free_from_pool(void *start, size_t size)
207 {
208         if (!dma_in_atomic_pool(start, size))
209                 return false;
210         gen_pool_free(atomic_pool, (unsigned long)start, size);
211         return true;
212 }
213 #endif /* CONFIG_DMA_DIRECT_REMAP */