Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/mm/consistent.c | |
3 | * | |
4 | * Copyright (C) 2000-2004 Russell King | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * DMA uncached mapping support. | |
11 | */ | |
12 | #include <linux/module.h> | |
13 | #include <linux/mm.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/errno.h> | |
16 | #include <linux/list.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/device.h> | |
19 | #include <linux/dma-mapping.h> | |
20 | ||
23759dc6 | 21 | #include <asm/memory.h> |
1da177e4 | 22 | #include <asm/cacheflush.h> |
1da177e4 | 23 | #include <asm/tlbflush.h> |
37134cd5 KH |
24 | #include <asm/sizes.h> |
25 | ||
26 | /* Sanity check size */ | |
27 | #if (CONSISTENT_DMA_SIZE % SZ_2M) | |
28 | #error "CONSISTENT_DMA_SIZE must be multiple of 2MiB" | |
29 | #endif | |
1da177e4 | 30 | |
1da177e4 | 31 | #define CONSISTENT_END (0xffe00000) |
37134cd5 KH |
32 | #define CONSISTENT_BASE (CONSISTENT_END - CONSISTENT_DMA_SIZE) |
33 | ||
1da177e4 | 34 | #define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT) |
37134cd5 KH |
35 | #define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PGDIR_SHIFT) |
36 | #define NUM_CONSISTENT_PTES (CONSISTENT_DMA_SIZE >> PGDIR_SHIFT) | |
37 | ||
1da177e4 LT |
38 | |
39 | /* | |
37134cd5 | 40 | * These are the page tables (2MB each) covering uncached, DMA consistent allocations |
1da177e4 | 41 | */ |
37134cd5 | 42 | static pte_t *consistent_pte[NUM_CONSISTENT_PTES]; |
1da177e4 LT |
43 | static DEFINE_SPINLOCK(consistent_lock); |
44 | ||
45 | /* | |
46 | * VM region handling support. | |
47 | * | |
48 | * This should become something generic, handling VM region allocations for | |
49 | * vmalloc and similar (ioremap, module space, etc). | |
50 | * | |
51 | * I envisage vmalloc()'s supporting vm_struct becoming: | |
52 | * | |
53 | * struct vm_struct { | |
54 | * struct vm_region region; | |
55 | * unsigned long flags; | |
56 | * struct page **pages; | |
57 | * unsigned int nr_pages; | |
58 | * unsigned long phys_addr; | |
59 | * }; | |
60 | * | |
61 | * get_vm_area() would then call vm_region_alloc with an appropriate | |
62 | * struct vm_region head (eg): | |
63 | * | |
64 | * struct vm_region vmalloc_head = { | |
65 | * .vm_list = LIST_HEAD_INIT(vmalloc_head.vm_list), | |
66 | * .vm_start = VMALLOC_START, | |
67 | * .vm_end = VMALLOC_END, | |
68 | * }; | |
69 | * | |
70 | * However, vmalloc_head.vm_start is variable (typically, it is dependent on | |
71 | * the amount of RAM found at boot time.) I would imagine that get_vm_area() | |
72 | * would have to initialise this each time prior to calling vm_region_alloc(). | |
73 | */ | |
74 | struct vm_region { | |
75 | struct list_head vm_list; | |
76 | unsigned long vm_start; | |
77 | unsigned long vm_end; | |
78 | struct page *vm_pages; | |
5edf71ae | 79 | int vm_active; |
1da177e4 LT |
80 | }; |
81 | ||
82 | static struct vm_region consistent_head = { | |
83 | .vm_list = LIST_HEAD_INIT(consistent_head.vm_list), | |
84 | .vm_start = CONSISTENT_BASE, | |
85 | .vm_end = CONSISTENT_END, | |
86 | }; | |
87 | ||
88 | static struct vm_region * | |
f9e3214a | 89 | vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp) |
1da177e4 LT |
90 | { |
91 | unsigned long addr = head->vm_start, end = head->vm_end - size; | |
92 | unsigned long flags; | |
93 | struct vm_region *c, *new; | |
94 | ||
95 | new = kmalloc(sizeof(struct vm_region), gfp); | |
96 | if (!new) | |
97 | goto out; | |
98 | ||
99 | spin_lock_irqsave(&consistent_lock, flags); | |
100 | ||
101 | list_for_each_entry(c, &head->vm_list, vm_list) { | |
102 | if ((addr + size) < addr) | |
103 | goto nospc; | |
104 | if ((addr + size) <= c->vm_start) | |
105 | goto found; | |
106 | addr = c->vm_end; | |
107 | if (addr > end) | |
108 | goto nospc; | |
109 | } | |
110 | ||
111 | found: | |
112 | /* | |
113 | * Insert this entry _before_ the one we found. | |
114 | */ | |
115 | list_add_tail(&new->vm_list, &c->vm_list); | |
116 | new->vm_start = addr; | |
117 | new->vm_end = addr + size; | |
5edf71ae | 118 | new->vm_active = 1; |
1da177e4 LT |
119 | |
120 | spin_unlock_irqrestore(&consistent_lock, flags); | |
121 | return new; | |
122 | ||
123 | nospc: | |
124 | spin_unlock_irqrestore(&consistent_lock, flags); | |
125 | kfree(new); | |
126 | out: | |
127 | return NULL; | |
128 | } | |
129 | ||
130 | static struct vm_region *vm_region_find(struct vm_region *head, unsigned long addr) | |
131 | { | |
132 | struct vm_region *c; | |
133 | ||
134 | list_for_each_entry(c, &head->vm_list, vm_list) { | |
5edf71ae | 135 | if (c->vm_active && c->vm_start == addr) |
1da177e4 LT |
136 | goto out; |
137 | } | |
138 | c = NULL; | |
139 | out: | |
140 | return c; | |
141 | } | |
142 | ||
143 | #ifdef CONFIG_HUGETLB_PAGE | |
144 | #error ARM Coherent DMA allocator does not (yet) support huge TLB | |
145 | #endif | |
146 | ||
147 | static void * | |
f9e3214a | 148 | __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, |
1da177e4 LT |
149 | pgprot_t prot) |
150 | { | |
151 | struct page *page; | |
152 | struct vm_region *c; | |
153 | unsigned long order; | |
154 | u64 mask = ISA_DMA_THRESHOLD, limit; | |
155 | ||
37134cd5 | 156 | if (!consistent_pte[0]) { |
1da177e4 LT |
157 | printk(KERN_ERR "%s: not initialised\n", __func__); |
158 | dump_stack(); | |
159 | return NULL; | |
160 | } | |
161 | ||
162 | if (dev) { | |
163 | mask = dev->coherent_dma_mask; | |
164 | ||
165 | /* | |
166 | * Sanity check the DMA mask - it must be non-zero, and | |
167 | * must be able to be satisfied by a DMA allocation. | |
168 | */ | |
169 | if (mask == 0) { | |
170 | dev_warn(dev, "coherent DMA mask is unset\n"); | |
171 | goto no_page; | |
172 | } | |
173 | ||
174 | if ((~mask) & ISA_DMA_THRESHOLD) { | |
175 | dev_warn(dev, "coherent DMA mask %#llx is smaller " | |
176 | "than system GFP_DMA mask %#llx\n", | |
177 | mask, (unsigned long long)ISA_DMA_THRESHOLD); | |
178 | goto no_page; | |
179 | } | |
180 | } | |
181 | ||
182 | /* | |
183 | * Sanity check the allocation size. | |
184 | */ | |
185 | size = PAGE_ALIGN(size); | |
186 | limit = (mask + 1) & ~mask; | |
187 | if ((limit && size >= limit) || | |
188 | size >= (CONSISTENT_END - CONSISTENT_BASE)) { | |
189 | printk(KERN_WARNING "coherent allocation too big " | |
190 | "(requested %#x mask %#llx)\n", size, mask); | |
191 | goto no_page; | |
192 | } | |
193 | ||
194 | order = get_order(size); | |
195 | ||
196 | if (mask != 0xffffffff) | |
197 | gfp |= GFP_DMA; | |
198 | ||
199 | page = alloc_pages(gfp, order); | |
200 | if (!page) | |
201 | goto no_page; | |
202 | ||
203 | /* | |
204 | * Invalidate any data that might be lurking in the | |
205 | * kernel direct-mapped region for device DMA. | |
206 | */ | |
207 | { | |
7ae5a761 RK |
208 | void *ptr = page_address(page); |
209 | memset(ptr, 0, size); | |
210 | dmac_flush_range(ptr, ptr + size); | |
211 | outer_flush_range(__pa(ptr), __pa(ptr) + size); | |
1da177e4 LT |
212 | } |
213 | ||
214 | /* | |
215 | * Allocate a virtual address in the consistent mapping region. | |
216 | */ | |
217 | c = vm_region_alloc(&consistent_head, size, | |
218 | gfp & ~(__GFP_DMA | __GFP_HIGHMEM)); | |
219 | if (c) { | |
37134cd5 | 220 | pte_t *pte; |
1da177e4 | 221 | struct page *end = page + (1 << order); |
37134cd5 KH |
222 | int idx = CONSISTENT_PTE_INDEX(c->vm_start); |
223 | u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1); | |
1da177e4 | 224 | |
37134cd5 | 225 | pte = consistent_pte[idx] + off; |
1da177e4 LT |
226 | c->vm_pages = page; |
227 | ||
8dfcc9ba NP |
228 | split_page(page, order); |
229 | ||
1da177e4 LT |
230 | /* |
231 | * Set the "dma handle" | |
232 | */ | |
233 | *handle = page_to_dma(dev, page); | |
234 | ||
235 | do { | |
236 | BUG_ON(!pte_none(*pte)); | |
237 | ||
1da177e4 LT |
238 | /* |
239 | * x86 does not mark the pages reserved... | |
240 | */ | |
241 | SetPageReserved(page); | |
ad1ae2fe | 242 | set_pte_ext(pte, mk_pte(page, prot), 0); |
1da177e4 LT |
243 | page++; |
244 | pte++; | |
37134cd5 KH |
245 | off++; |
246 | if (off >= PTRS_PER_PTE) { | |
247 | off = 0; | |
248 | pte = consistent_pte[++idx]; | |
249 | } | |
1da177e4 LT |
250 | } while (size -= PAGE_SIZE); |
251 | ||
252 | /* | |
253 | * Free the otherwise unused pages. | |
254 | */ | |
255 | while (page < end) { | |
1da177e4 LT |
256 | __free_page(page); |
257 | page++; | |
258 | } | |
259 | ||
260 | return (void *)c->vm_start; | |
261 | } | |
262 | ||
263 | if (page) | |
264 | __free_pages(page, order); | |
265 | no_page: | |
266 | *handle = ~0; | |
267 | return NULL; | |
268 | } | |
269 | ||
270 | /* | |
271 | * Allocate DMA-coherent memory space and return both the kernel remapped | |
272 | * virtual and bus address for that space. | |
273 | */ | |
274 | void * | |
f9e3214a | 275 | dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) |
1da177e4 | 276 | { |
23759dc6 LB |
277 | if (arch_is_coherent()) { |
278 | void *virt; | |
279 | ||
280 | virt = kmalloc(size, gfp); | |
281 | if (!virt) | |
282 | return NULL; | |
283 | *handle = virt_to_dma(dev, virt); | |
284 | ||
285 | return virt; | |
286 | } | |
287 | ||
1da177e4 LT |
288 | return __dma_alloc(dev, size, handle, gfp, |
289 | pgprot_noncached(pgprot_kernel)); | |
290 | } | |
291 | EXPORT_SYMBOL(dma_alloc_coherent); | |
292 | ||
293 | /* | |
294 | * Allocate a writecombining region, in much the same way as | |
295 | * dma_alloc_coherent above. | |
296 | */ | |
297 | void * | |
f9e3214a | 298 | dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) |
1da177e4 LT |
299 | { |
300 | return __dma_alloc(dev, size, handle, gfp, | |
301 | pgprot_writecombine(pgprot_kernel)); | |
302 | } | |
303 | EXPORT_SYMBOL(dma_alloc_writecombine); | |
304 | ||
305 | static int dma_mmap(struct device *dev, struct vm_area_struct *vma, | |
306 | void *cpu_addr, dma_addr_t dma_addr, size_t size) | |
307 | { | |
308 | unsigned long flags, user_size, kern_size; | |
309 | struct vm_region *c; | |
310 | int ret = -ENXIO; | |
311 | ||
312 | user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
313 | ||
314 | spin_lock_irqsave(&consistent_lock, flags); | |
315 | c = vm_region_find(&consistent_head, (unsigned long)cpu_addr); | |
316 | spin_unlock_irqrestore(&consistent_lock, flags); | |
317 | ||
318 | if (c) { | |
319 | unsigned long off = vma->vm_pgoff; | |
320 | ||
321 | kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT; | |
322 | ||
323 | if (off < kern_size && | |
324 | user_size <= (kern_size - off)) { | |
325 | vma->vm_flags |= VM_RESERVED; | |
326 | ret = remap_pfn_range(vma, vma->vm_start, | |
327 | page_to_pfn(c->vm_pages) + off, | |
328 | user_size << PAGE_SHIFT, | |
329 | vma->vm_page_prot); | |
330 | } | |
331 | } | |
332 | ||
333 | return ret; | |
334 | } | |
335 | ||
336 | int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma, | |
337 | void *cpu_addr, dma_addr_t dma_addr, size_t size) | |
338 | { | |
339 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); | |
340 | return dma_mmap(dev, vma, cpu_addr, dma_addr, size); | |
341 | } | |
342 | EXPORT_SYMBOL(dma_mmap_coherent); | |
343 | ||
344 | int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma, | |
345 | void *cpu_addr, dma_addr_t dma_addr, size_t size) | |
346 | { | |
347 | vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); | |
348 | return dma_mmap(dev, vma, cpu_addr, dma_addr, size); | |
349 | } | |
350 | EXPORT_SYMBOL(dma_mmap_writecombine); | |
351 | ||
352 | /* | |
353 | * free a page as defined by the above mapping. | |
5edf71ae | 354 | * Must not be called with IRQs disabled. |
1da177e4 LT |
355 | */ |
356 | void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle) | |
357 | { | |
358 | struct vm_region *c; | |
359 | unsigned long flags, addr; | |
360 | pte_t *ptep; | |
37134cd5 KH |
361 | int idx; |
362 | u32 off; | |
1da177e4 | 363 | |
5edf71ae RK |
364 | WARN_ON(irqs_disabled()); |
365 | ||
23759dc6 LB |
366 | if (arch_is_coherent()) { |
367 | kfree(cpu_addr); | |
368 | return; | |
369 | } | |
370 | ||
1da177e4 LT |
371 | size = PAGE_ALIGN(size); |
372 | ||
373 | spin_lock_irqsave(&consistent_lock, flags); | |
1da177e4 LT |
374 | c = vm_region_find(&consistent_head, (unsigned long)cpu_addr); |
375 | if (!c) | |
376 | goto no_area; | |
377 | ||
5edf71ae RK |
378 | c->vm_active = 0; |
379 | spin_unlock_irqrestore(&consistent_lock, flags); | |
380 | ||
1da177e4 LT |
381 | if ((c->vm_end - c->vm_start) != size) { |
382 | printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n", | |
383 | __func__, c->vm_end - c->vm_start, size); | |
384 | dump_stack(); | |
385 | size = c->vm_end - c->vm_start; | |
386 | } | |
387 | ||
37134cd5 KH |
388 | idx = CONSISTENT_PTE_INDEX(c->vm_start); |
389 | off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1); | |
390 | ptep = consistent_pte[idx] + off; | |
1da177e4 LT |
391 | addr = c->vm_start; |
392 | do { | |
393 | pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep); | |
394 | unsigned long pfn; | |
395 | ||
396 | ptep++; | |
397 | addr += PAGE_SIZE; | |
37134cd5 KH |
398 | off++; |
399 | if (off >= PTRS_PER_PTE) { | |
400 | off = 0; | |
401 | ptep = consistent_pte[++idx]; | |
402 | } | |
1da177e4 LT |
403 | |
404 | if (!pte_none(pte) && pte_present(pte)) { | |
405 | pfn = pte_pfn(pte); | |
406 | ||
407 | if (pfn_valid(pfn)) { | |
408 | struct page *page = pfn_to_page(pfn); | |
409 | ||
410 | /* | |
411 | * x86 does not mark the pages reserved... | |
412 | */ | |
413 | ClearPageReserved(page); | |
414 | ||
415 | __free_page(page); | |
416 | continue; | |
417 | } | |
418 | } | |
419 | ||
420 | printk(KERN_CRIT "%s: bad page in kernel page table\n", | |
421 | __func__); | |
422 | } while (size -= PAGE_SIZE); | |
423 | ||
424 | flush_tlb_kernel_range(c->vm_start, c->vm_end); | |
425 | ||
5edf71ae | 426 | spin_lock_irqsave(&consistent_lock, flags); |
1da177e4 | 427 | list_del(&c->vm_list); |
1da177e4 LT |
428 | spin_unlock_irqrestore(&consistent_lock, flags); |
429 | ||
430 | kfree(c); | |
431 | return; | |
432 | ||
433 | no_area: | |
434 | spin_unlock_irqrestore(&consistent_lock, flags); | |
435 | printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n", | |
436 | __func__, cpu_addr); | |
437 | dump_stack(); | |
438 | } | |
439 | EXPORT_SYMBOL(dma_free_coherent); | |
440 | ||
441 | /* | |
442 | * Initialise the consistent memory allocation. | |
443 | */ | |
444 | static int __init consistent_init(void) | |
445 | { | |
446 | pgd_t *pgd; | |
447 | pmd_t *pmd; | |
448 | pte_t *pte; | |
37134cd5 KH |
449 | int ret = 0, i = 0; |
450 | u32 base = CONSISTENT_BASE; | |
1da177e4 | 451 | |
1da177e4 | 452 | do { |
37134cd5 KH |
453 | pgd = pgd_offset(&init_mm, base); |
454 | pmd = pmd_alloc(&init_mm, pgd, base); | |
1da177e4 LT |
455 | if (!pmd) { |
456 | printk(KERN_ERR "%s: no pmd tables\n", __func__); | |
457 | ret = -ENOMEM; | |
458 | break; | |
459 | } | |
460 | WARN_ON(!pmd_none(*pmd)); | |
461 | ||
37134cd5 | 462 | pte = pte_alloc_kernel(pmd, base); |
1da177e4 LT |
463 | if (!pte) { |
464 | printk(KERN_ERR "%s: no pte tables\n", __func__); | |
465 | ret = -ENOMEM; | |
466 | break; | |
467 | } | |
468 | ||
37134cd5 KH |
469 | consistent_pte[i++] = pte; |
470 | base += (1 << PGDIR_SHIFT); | |
471 | } while (base < CONSISTENT_END); | |
1da177e4 | 472 | |
1da177e4 LT |
473 | return ret; |
474 | } | |
475 | ||
476 | core_initcall(consistent_init); | |
477 | ||
478 | /* | |
479 | * Make an area consistent for devices. | |
105ef9a0 DW |
480 | * Note: Drivers should NOT use this function directly, as it will break |
481 | * platforms with CONFIG_DMABOUNCE. | |
482 | * Use the driver DMA support - see dma-mapping.h (dma_sync_*) | |
1da177e4 | 483 | */ |
7ae5a761 | 484 | void consistent_sync(const void *start, size_t size, int direction) |
1da177e4 | 485 | { |
7ae5a761 | 486 | const void *end = start + size; |
1da177e4 | 487 | |
953233dc CM |
488 | BUG_ON(!virt_addr_valid(start) || !virt_addr_valid(end)); |
489 | ||
1da177e4 LT |
490 | switch (direction) { |
491 | case DMA_FROM_DEVICE: /* invalidate only */ | |
492 | dmac_inv_range(start, end); | |
953233dc | 493 | outer_inv_range(__pa(start), __pa(end)); |
1da177e4 LT |
494 | break; |
495 | case DMA_TO_DEVICE: /* writeback only */ | |
496 | dmac_clean_range(start, end); | |
953233dc | 497 | outer_clean_range(__pa(start), __pa(end)); |
1da177e4 LT |
498 | break; |
499 | case DMA_BIDIRECTIONAL: /* writeback and invalidate */ | |
500 | dmac_flush_range(start, end); | |
953233dc | 501 | outer_flush_range(__pa(start), __pa(end)); |
1da177e4 LT |
502 | break; |
503 | default: | |
504 | BUG(); | |
505 | } | |
506 | } | |
507 | EXPORT_SYMBOL(consistent_sync); |