b481c48a31a630284f9c32d94213a210ea792334
[linux-modified.git] / pool.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  * Copyright (C) 2020 Google LLC
5  */
6 #include <linux/cma.h>
7 #include <linux/debugfs.h>
8 #include <linux/dma-map-ops.h>
9 #include <linux/dma-direct.h>
10 #include <linux/init.h>
11 #include <linux/genalloc.h>
12 #include <linux/set_memory.h>
13 #include <linux/slab.h>
14 #include <linux/workqueue.h>
15
16 static struct gen_pool *atomic_pool_dma __ro_after_init;
17 static unsigned long pool_size_dma;
18 static struct gen_pool *atomic_pool_dma32 __ro_after_init;
19 static unsigned long pool_size_dma32;
20 static struct gen_pool *atomic_pool_kernel __ro_after_init;
21 static unsigned long pool_size_kernel;
22
23 /* Size can be defined by the coherent_pool command line */
24 static size_t atomic_pool_size;
25
26 /* Dynamic background expansion when the atomic pool is near capacity */
27 static struct work_struct atomic_pool_work;
28
29 static int __init early_coherent_pool(char *p)
30 {
31         atomic_pool_size = memparse(p, &p);
32         return 0;
33 }
34 early_param("coherent_pool", early_coherent_pool);
35
36 static void __init dma_atomic_pool_debugfs_init(void)
37 {
38         struct dentry *root;
39
40         root = debugfs_create_dir("dma_pools", NULL);
41         debugfs_create_ulong("pool_size_dma", 0400, root, &pool_size_dma);
42         debugfs_create_ulong("pool_size_dma32", 0400, root, &pool_size_dma32);
43         debugfs_create_ulong("pool_size_kernel", 0400, root, &pool_size_kernel);
44 }
45
46 static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
47 {
48         if (gfp & __GFP_DMA)
49                 pool_size_dma += size;
50         else if (gfp & __GFP_DMA32)
51                 pool_size_dma32 += size;
52         else
53                 pool_size_kernel += size;
54 }
55
56 static bool cma_in_zone(gfp_t gfp)
57 {
58         unsigned long size;
59         phys_addr_t end;
60         struct cma *cma;
61
62         cma = dev_get_cma_area(NULL);
63         if (!cma)
64                 return false;
65
66         size = cma_get_size(cma);
67         if (!size)
68                 return false;
69
70         /* CMA can't cross zone boundaries, see cma_activate_area() */
71         end = cma_get_base(cma) + size - 1;
72         if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
73                 return end <= DMA_BIT_MASK(zone_dma_bits);
74         if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
75                 return end <= DMA_BIT_MASK(32);
76         return true;
77 }
78
79 static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
80                               gfp_t gfp)
81 {
82         unsigned int order;
83         struct page *page = NULL;
84         void *addr;
85         int ret = -ENOMEM;
86
87         /* Cannot allocate larger than MAX_ORDER */
88         order = min(get_order(pool_size), MAX_ORDER);
89
90         do {
91                 pool_size = 1 << (PAGE_SHIFT + order);
92                 if (cma_in_zone(gfp))
93                         page = dma_alloc_from_contiguous(NULL, 1 << order,
94                                                          order, false);
95                 if (!page)
96                         page = alloc_pages(gfp, order);
97         } while (!page && order-- > 0);
98         if (!page)
99                 goto out;
100
101         arch_dma_prep_coherent(page, pool_size);
102
103 #ifdef CONFIG_DMA_DIRECT_REMAP
104         addr = dma_common_contiguous_remap(page, pool_size,
105                                            pgprot_dmacoherent(PAGE_KERNEL),
106                                            __builtin_return_address(0));
107         if (!addr)
108                 goto free_page;
109 #else
110         addr = page_to_virt(page);
111 #endif
112         /*
113          * Memory in the atomic DMA pools must be unencrypted, the pools do not
114          * shrink so no re-encryption occurs in dma_direct_free().
115          */
116         ret = set_memory_decrypted((unsigned long)page_to_virt(page),
117                                    1 << order);
118         if (ret)
119                 goto remove_mapping;
120         ret = gen_pool_add_virt(pool, (unsigned long)addr, page_to_phys(page),
121                                 pool_size, NUMA_NO_NODE);
122         if (ret)
123                 goto encrypt_mapping;
124
125         dma_atomic_pool_size_add(gfp, pool_size);
126         return 0;
127
128 encrypt_mapping:
129         ret = set_memory_encrypted((unsigned long)page_to_virt(page),
130                                    1 << order);
131         if (WARN_ON_ONCE(ret)) {
132                 /* Decrypt succeeded but encrypt failed, purposely leak */
133                 goto out;
134         }
135 remove_mapping:
136 #ifdef CONFIG_DMA_DIRECT_REMAP
137         dma_common_free_remap(addr, pool_size);
138 free_page:
139         __free_pages(page, order);
140 #endif
141 out:
142         return ret;
143 }
144
145 static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp)
146 {
147         if (pool && gen_pool_avail(pool) < atomic_pool_size)
148                 atomic_pool_expand(pool, gen_pool_size(pool), gfp);
149 }
150
151 static void atomic_pool_work_fn(struct work_struct *work)
152 {
153         if (IS_ENABLED(CONFIG_ZONE_DMA))
154                 atomic_pool_resize(atomic_pool_dma,
155                                    GFP_KERNEL | GFP_DMA);
156         if (IS_ENABLED(CONFIG_ZONE_DMA32))
157                 atomic_pool_resize(atomic_pool_dma32,
158                                    GFP_KERNEL | GFP_DMA32);
159         atomic_pool_resize(atomic_pool_kernel, GFP_KERNEL);
160 }
161
162 static __init struct gen_pool *__dma_atomic_pool_init(size_t pool_size,
163                                                       gfp_t gfp)
164 {
165         struct gen_pool *pool;
166         int ret;
167
168         pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
169         if (!pool)
170                 return NULL;
171
172         gen_pool_set_algo(pool, gen_pool_first_fit_order_align, NULL);
173
174         ret = atomic_pool_expand(pool, pool_size, gfp);
175         if (ret) {
176                 gen_pool_destroy(pool);
177                 pr_err("DMA: failed to allocate %zu KiB %pGg pool for atomic allocation\n",
178                        pool_size >> 10, &gfp);
179                 return NULL;
180         }
181
182         pr_info("DMA: preallocated %zu KiB %pGg pool for atomic allocations\n",
183                 gen_pool_size(pool) >> 10, &gfp);
184         return pool;
185 }
186
187 static int __init dma_atomic_pool_init(void)
188 {
189         int ret = 0;
190
191         /*
192          * If coherent_pool was not used on the command line, default the pool
193          * sizes to 128KB per 1GB of memory, min 128KB, max MAX_ORDER.
194          */
195         if (!atomic_pool_size) {
196                 unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K);
197                 pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES);
198                 atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K);
199         }
200         INIT_WORK(&atomic_pool_work, atomic_pool_work_fn);
201
202         atomic_pool_kernel = __dma_atomic_pool_init(atomic_pool_size,
203                                                     GFP_KERNEL);
204         if (!atomic_pool_kernel)
205                 ret = -ENOMEM;
206         if (has_managed_dma()) {
207                 atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size,
208                                                 GFP_KERNEL | GFP_DMA);
209                 if (!atomic_pool_dma)
210                         ret = -ENOMEM;
211         }
212         if (IS_ENABLED(CONFIG_ZONE_DMA32)) {
213                 atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size,
214                                                 GFP_KERNEL | GFP_DMA32);
215                 if (!atomic_pool_dma32)
216                         ret = -ENOMEM;
217         }
218
219         dma_atomic_pool_debugfs_init();
220         return ret;
221 }
222 postcore_initcall(dma_atomic_pool_init);
223
224 static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp)
225 {
226         if (prev == NULL) {
227                 if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
228                         return atomic_pool_dma32;
229                 if (atomic_pool_dma && (gfp & GFP_DMA))
230                         return atomic_pool_dma;
231                 return atomic_pool_kernel;
232         }
233         if (prev == atomic_pool_kernel)
234                 return atomic_pool_dma32 ? atomic_pool_dma32 : atomic_pool_dma;
235         if (prev == atomic_pool_dma32)
236                 return atomic_pool_dma;
237         return NULL;
238 }
239
240 static struct page *__dma_alloc_from_pool(struct device *dev, size_t size,
241                 struct gen_pool *pool, void **cpu_addr,
242                 bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
243 {
244         unsigned long addr;
245         phys_addr_t phys;
246
247         addr = gen_pool_alloc(pool, size);
248         if (!addr)
249                 return NULL;
250
251         phys = gen_pool_virt_to_phys(pool, addr);
252         if (phys_addr_ok && !phys_addr_ok(dev, phys, size)) {
253                 gen_pool_free(pool, addr, size);
254                 return NULL;
255         }
256
257         if (gen_pool_avail(pool) < atomic_pool_size)
258                 schedule_work(&atomic_pool_work);
259
260         *cpu_addr = (void *)addr;
261         memset(*cpu_addr, 0, size);
262         return pfn_to_page(__phys_to_pfn(phys));
263 }
264
265 struct page *dma_alloc_from_pool(struct device *dev, size_t size,
266                 void **cpu_addr, gfp_t gfp,
267                 bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t))
268 {
269         struct gen_pool *pool = NULL;
270         struct page *page;
271
272         while ((pool = dma_guess_pool(pool, gfp))) {
273                 page = __dma_alloc_from_pool(dev, size, pool, cpu_addr,
274                                              phys_addr_ok);
275                 if (page)
276                         return page;
277         }
278
279         WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev));
280         return NULL;
281 }
282
283 bool dma_free_from_pool(struct device *dev, void *start, size_t size)
284 {
285         struct gen_pool *pool = NULL;
286
287         while ((pool = dma_guess_pool(pool, 0))) {
288                 if (!gen_pool_has_addr(pool, (unsigned long)start, size))
289                         continue;
290                 gen_pool_free(pool, (unsigned long)start, size);
291                 return true;
292         }
293
294         return false;
295 }