Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * PowerPC version derived from arch/arm/mm/consistent.c | |
3 | * Copyright (C) 2001 Dan Malek (dmalek@jlc.net) | |
4 | * | |
5 | * Copyright (C) 2000 Russell King | |
6 | * | |
7 | * Consistent memory allocators. Used for DMA devices that want to | |
8 | * share uncached memory with the processor core. The function return | |
9 | * is the virtual address and 'dma_handle' is the physical address. | |
10 | * Mostly stolen from the ARM port, with some changes for PowerPC. | |
11 | * -- Dan | |
12 | * | |
13 | * Reorganized to get rid of the arch-specific consistent_* functions | |
14 | * and provide non-coherent implementations for the DMA API. -Matt | |
15 | * | |
16 | * Added in_interrupt() safe dma_alloc_coherent()/dma_free_coherent() | |
17 | * implementation. This is pulled straight from ARM and barely | |
18 | * modified. -Matt | |
19 | * | |
20 | * This program is free software; you can redistribute it and/or modify | |
21 | * it under the terms of the GNU General Public License version 2 as | |
22 | * published by the Free Software Foundation. | |
23 | */ | |
24 | ||
1da177e4 LT |
25 | #include <linux/sched.h> |
26 | #include <linux/kernel.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/string.h> | |
29 | #include <linux/types.h> | |
1da177e4 LT |
30 | #include <linux/highmem.h> |
31 | #include <linux/dma-mapping.h> | |
1da177e4 LT |
32 | |
33 | #include <asm/tlbflush.h> | |
34 | ||
84532a0f BH |
35 | /* |
36 | * This address range defaults to a value that is safe for all | |
37 | * platforms which currently set CONFIG_NOT_COHERENT_CACHE. It | |
38 | * can be further configured for specific applications under | |
39 | * the "Advanced Setup" menu. -Matt | |
40 | */ | |
41 | #define CONSISTENT_BASE (CONFIG_CONSISTENT_START) | |
42 | #define CONSISTENT_END (CONFIG_CONSISTENT_START + CONFIG_CONSISTENT_SIZE) | |
43 | #define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT) | |
44 | ||
45 | /* | |
46 | * This is the page table (2MB) covering uncached, DMA consistent allocations | |
47 | */ | |
48 | static pte_t *consistent_pte; | |
49 | static DEFINE_SPINLOCK(consistent_lock); | |
50 | ||
51 | /* | |
52 | * VM region handling support. | |
53 | * | |
54 | * This should become something generic, handling VM region allocations for | |
55 | * vmalloc and similar (ioremap, module space, etc). | |
56 | * | |
57 | * I envisage vmalloc()'s supporting vm_struct becoming: | |
58 | * | |
59 | * struct vm_struct { | |
60 | * struct vm_region region; | |
61 | * unsigned long flags; | |
62 | * struct page **pages; | |
63 | * unsigned int nr_pages; | |
64 | * unsigned long phys_addr; | |
65 | * }; | |
66 | * | |
67 | * get_vm_area() would then call vm_region_alloc with an appropriate | |
68 | * struct vm_region head (eg): | |
69 | * | |
70 | * struct vm_region vmalloc_head = { | |
71 | * .vm_list = LIST_HEAD_INIT(vmalloc_head.vm_list), | |
72 | * .vm_start = VMALLOC_START, | |
73 | * .vm_end = VMALLOC_END, | |
74 | * }; | |
75 | * | |
76 | * However, vmalloc_head.vm_start is variable (typically, it is dependent on | |
77 | * the amount of RAM found at boot time.) I would imagine that get_vm_area() | |
78 | * would have to initialise this each time prior to calling vm_region_alloc(). | |
79 | */ | |
80 | struct ppc_vm_region { | |
81 | struct list_head vm_list; | |
82 | unsigned long vm_start; | |
83 | unsigned long vm_end; | |
84 | }; | |
85 | ||
86 | static struct ppc_vm_region consistent_head = { | |
87 | .vm_list = LIST_HEAD_INIT(consistent_head.vm_list), | |
88 | .vm_start = CONSISTENT_BASE, | |
89 | .vm_end = CONSISTENT_END, | |
90 | }; | |
91 | ||
92 | static struct ppc_vm_region * | |
93 | ppc_vm_region_alloc(struct ppc_vm_region *head, size_t size, gfp_t gfp) | |
94 | { | |
95 | unsigned long addr = head->vm_start, end = head->vm_end - size; | |
96 | unsigned long flags; | |
97 | struct ppc_vm_region *c, *new; | |
98 | ||
99 | new = kmalloc(sizeof(struct ppc_vm_region), gfp); | |
100 | if (!new) | |
101 | goto out; | |
102 | ||
103 | spin_lock_irqsave(&consistent_lock, flags); | |
104 | ||
105 | list_for_each_entry(c, &head->vm_list, vm_list) { | |
106 | if ((addr + size) < addr) | |
107 | goto nospc; | |
108 | if ((addr + size) <= c->vm_start) | |
109 | goto found; | |
110 | addr = c->vm_end; | |
111 | if (addr > end) | |
112 | goto nospc; | |
113 | } | |
114 | ||
115 | found: | |
116 | /* | |
117 | * Insert this entry _before_ the one we found. | |
118 | */ | |
119 | list_add_tail(&new->vm_list, &c->vm_list); | |
120 | new->vm_start = addr; | |
121 | new->vm_end = addr + size; | |
122 | ||
123 | spin_unlock_irqrestore(&consistent_lock, flags); | |
124 | return new; | |
125 | ||
126 | nospc: | |
127 | spin_unlock_irqrestore(&consistent_lock, flags); | |
128 | kfree(new); | |
129 | out: | |
130 | return NULL; | |
131 | } | |
132 | ||
133 | static struct ppc_vm_region *ppc_vm_region_find(struct ppc_vm_region *head, unsigned long addr) | |
134 | { | |
135 | struct ppc_vm_region *c; | |
136 | ||
137 | list_for_each_entry(c, &head->vm_list, vm_list) { | |
138 | if (c->vm_start == addr) | |
139 | goto out; | |
140 | } | |
141 | c = NULL; | |
142 | out: | |
143 | return c; | |
144 | } | |
145 | ||
1da177e4 LT |
146 | /* |
147 | * Allocate DMA-coherent memory space and return both the kernel remapped | |
148 | * virtual and bus address for that space. | |
149 | */ | |
150 | void * | |
e82dd4d6 | 151 | __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp) |
1da177e4 LT |
152 | { |
153 | struct page *page; | |
84532a0f | 154 | struct ppc_vm_region *c; |
1da177e4 LT |
155 | unsigned long order; |
156 | u64 mask = 0x00ffffff, limit; /* ISA default */ | |
157 | ||
84532a0f BH |
158 | if (!consistent_pte) { |
159 | printk(KERN_ERR "%s: not initialised\n", __func__); | |
160 | dump_stack(); | |
161 | return NULL; | |
162 | } | |
163 | ||
1da177e4 LT |
164 | size = PAGE_ALIGN(size); |
165 | limit = (mask + 1) & ~mask; | |
84532a0f BH |
166 | if ((limit && size >= limit) || size >= (CONSISTENT_END - CONSISTENT_BASE)) { |
167 | printk(KERN_WARNING "coherent allocation too big (requested %#x mask %#Lx)\n", | |
168 | size, mask); | |
1da177e4 LT |
169 | return NULL; |
170 | } | |
171 | ||
172 | order = get_order(size); | |
173 | ||
174 | if (mask != 0xffffffff) | |
175 | gfp |= GFP_DMA; | |
176 | ||
177 | page = alloc_pages(gfp, order); | |
178 | if (!page) | |
179 | goto no_page; | |
180 | ||
181 | /* | |
182 | * Invalidate any data that might be lurking in the | |
183 | * kernel direct-mapped region for device DMA. | |
184 | */ | |
185 | { | |
186 | unsigned long kaddr = (unsigned long)page_address(page); | |
187 | memset(page_address(page), 0, size); | |
188 | flush_dcache_range(kaddr, kaddr + size); | |
189 | } | |
190 | ||
191 | /* | |
84532a0f | 192 | * Allocate a virtual address in the consistent mapping region. |
1da177e4 | 193 | */ |
84532a0f BH |
194 | c = ppc_vm_region_alloc(&consistent_head, size, |
195 | gfp & ~(__GFP_DMA | __GFP_HIGHMEM)); | |
196 | if (c) { | |
197 | unsigned long vaddr = c->vm_start; | |
198 | pte_t *pte = consistent_pte + CONSISTENT_OFFSET(vaddr); | |
199 | struct page *end = page + (1 << order); | |
1da177e4 | 200 | |
84532a0f BH |
201 | split_page(page, order); |
202 | ||
203 | /* | |
204 | * Set the "dma handle" | |
205 | */ | |
206 | *handle = page_to_phys(page); | |
1da177e4 | 207 | |
84532a0f BH |
208 | do { |
209 | BUG_ON(!pte_none(*pte)); | |
1da177e4 | 210 | |
84532a0f BH |
211 | SetPageReserved(page); |
212 | set_pte_at(&init_mm, vaddr, | |
213 | pte, mk_pte(page, pgprot_noncached(PAGE_KERNEL))); | |
214 | page++; | |
215 | pte++; | |
216 | vaddr += PAGE_SIZE; | |
217 | } while (size -= PAGE_SIZE); | |
1da177e4 | 218 | |
84532a0f BH |
219 | /* |
220 | * Free the otherwise unused pages. | |
221 | */ | |
222 | while (page < end) { | |
223 | __free_page(page); | |
224 | page++; | |
225 | } | |
226 | ||
227 | return (void *)c->vm_start; | |
1da177e4 LT |
228 | } |
229 | ||
230 | if (page) | |
231 | __free_pages(page, order); | |
84532a0f | 232 | no_page: |
1da177e4 LT |
233 | return NULL; |
234 | } | |
235 | EXPORT_SYMBOL(__dma_alloc_coherent); | |
236 | ||
237 | /* | |
238 | * free a page as defined by the above mapping. | |
239 | */ | |
240 | void __dma_free_coherent(size_t size, void *vaddr) | |
241 | { | |
84532a0f BH |
242 | struct ppc_vm_region *c; |
243 | unsigned long flags, addr; | |
244 | pte_t *ptep; | |
245 | ||
246 | size = PAGE_ALIGN(size); | |
247 | ||
248 | spin_lock_irqsave(&consistent_lock, flags); | |
249 | ||
250 | c = ppc_vm_region_find(&consistent_head, (unsigned long)vaddr); | |
251 | if (!c) | |
252 | goto no_area; | |
253 | ||
254 | if ((c->vm_end - c->vm_start) != size) { | |
255 | printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n", | |
256 | __func__, c->vm_end - c->vm_start, size); | |
257 | dump_stack(); | |
258 | size = c->vm_end - c->vm_start; | |
259 | } | |
260 | ||
261 | ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start); | |
262 | addr = c->vm_start; | |
263 | do { | |
264 | pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep); | |
265 | unsigned long pfn; | |
266 | ||
267 | ptep++; | |
268 | addr += PAGE_SIZE; | |
1da177e4 | 269 | |
84532a0f BH |
270 | if (!pte_none(pte) && pte_present(pte)) { |
271 | pfn = pte_pfn(pte); | |
272 | ||
273 | if (pfn_valid(pfn)) { | |
274 | struct page *page = pfn_to_page(pfn); | |
275 | ClearPageReserved(page); | |
276 | ||
277 | __free_page(page); | |
278 | continue; | |
279 | } | |
280 | } | |
281 | ||
282 | printk(KERN_CRIT "%s: bad page in kernel page table\n", | |
283 | __func__); | |
284 | } while (size -= PAGE_SIZE); | |
285 | ||
286 | flush_tlb_kernel_range(c->vm_start, c->vm_end); | |
287 | ||
288 | list_del(&c->vm_list); | |
289 | ||
290 | spin_unlock_irqrestore(&consistent_lock, flags); | |
291 | ||
292 | kfree(c); | |
293 | return; | |
294 | ||
295 | no_area: | |
296 | spin_unlock_irqrestore(&consistent_lock, flags); | |
297 | printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n", | |
298 | __func__, vaddr); | |
299 | dump_stack(); | |
1da177e4 LT |
300 | } |
301 | EXPORT_SYMBOL(__dma_free_coherent); | |
302 | ||
84532a0f BH |
303 | /* |
304 | * Initialise the consistent memory allocation. | |
305 | */ | |
306 | static int __init dma_alloc_init(void) | |
307 | { | |
308 | pgd_t *pgd; | |
309 | pud_t *pud; | |
310 | pmd_t *pmd; | |
311 | pte_t *pte; | |
312 | int ret = 0; | |
313 | ||
314 | do { | |
315 | pgd = pgd_offset(&init_mm, CONSISTENT_BASE); | |
316 | pud = pud_alloc(&init_mm, pgd, CONSISTENT_BASE); | |
317 | pmd = pmd_alloc(&init_mm, pud, CONSISTENT_BASE); | |
318 | if (!pmd) { | |
319 | printk(KERN_ERR "%s: no pmd tables\n", __func__); | |
320 | ret = -ENOMEM; | |
321 | break; | |
322 | } | |
323 | ||
324 | pte = pte_alloc_kernel(pmd, CONSISTENT_BASE); | |
325 | if (!pte) { | |
326 | printk(KERN_ERR "%s: no pte tables\n", __func__); | |
327 | ret = -ENOMEM; | |
328 | break; | |
329 | } | |
330 | ||
331 | consistent_pte = pte; | |
332 | } while (0); | |
333 | ||
334 | return ret; | |
335 | } | |
336 | ||
337 | core_initcall(dma_alloc_init); | |
338 | ||
1da177e4 LT |
339 | /* |
340 | * make an area consistent. | |
341 | */ | |
342 | void __dma_sync(void *vaddr, size_t size, int direction) | |
343 | { | |
344 | unsigned long start = (unsigned long)vaddr; | |
345 | unsigned long end = start + size; | |
346 | ||
347 | switch (direction) { | |
348 | case DMA_NONE: | |
349 | BUG(); | |
03d70617 AL |
350 | case DMA_FROM_DEVICE: |
351 | /* | |
352 | * invalidate only when cache-line aligned otherwise there is | |
353 | * the potential for discarding uncommitted data from the cache | |
354 | */ | |
355 | if ((start & (L1_CACHE_BYTES - 1)) || (size & (L1_CACHE_BYTES - 1))) | |
356 | flush_dcache_range(start, end); | |
357 | else | |
358 | invalidate_dcache_range(start, end); | |
1da177e4 LT |
359 | break; |
360 | case DMA_TO_DEVICE: /* writeback only */ | |
361 | clean_dcache_range(start, end); | |
362 | break; | |
363 | case DMA_BIDIRECTIONAL: /* writeback and invalidate */ | |
364 | flush_dcache_range(start, end); | |
365 | break; | |
366 | } | |
367 | } | |
368 | EXPORT_SYMBOL(__dma_sync); | |
369 | ||
370 | #ifdef CONFIG_HIGHMEM | |
371 | /* | |
372 | * __dma_sync_page() implementation for systems using highmem. | |
373 | * In this case, each page of a buffer must be kmapped/kunmapped | |
374 | * in order to have a virtual address for __dma_sync(). This must | |
338cec32 | 375 | * not sleep so kmap_atomic()/kunmap_atomic() are used. |
1da177e4 LT |
376 | * |
377 | * Note: yes, it is possible and correct to have a buffer extend | |
378 | * beyond the first page. | |
379 | */ | |
380 | static inline void __dma_sync_page_highmem(struct page *page, | |
381 | unsigned long offset, size_t size, int direction) | |
382 | { | |
a0c111c6 | 383 | size_t seg_size = min((size_t)(PAGE_SIZE - offset), size); |
1da177e4 LT |
384 | size_t cur_size = seg_size; |
385 | unsigned long flags, start, seg_offset = offset; | |
a0c111c6 | 386 | int nr_segs = 1 + ((size - seg_size) + PAGE_SIZE - 1)/PAGE_SIZE; |
1da177e4 LT |
387 | int seg_nr = 0; |
388 | ||
389 | local_irq_save(flags); | |
390 | ||
391 | do { | |
392 | start = (unsigned long)kmap_atomic(page + seg_nr, | |
393 | KM_PPC_SYNC_PAGE) + seg_offset; | |
394 | ||
395 | /* Sync this buffer segment */ | |
396 | __dma_sync((void *)start, seg_size, direction); | |
397 | kunmap_atomic((void *)start, KM_PPC_SYNC_PAGE); | |
398 | seg_nr++; | |
399 | ||
400 | /* Calculate next buffer segment size */ | |
401 | seg_size = min((size_t)PAGE_SIZE, size - cur_size); | |
402 | ||
403 | /* Add the segment size to our running total */ | |
404 | cur_size += seg_size; | |
405 | seg_offset = 0; | |
406 | } while (seg_nr < nr_segs); | |
407 | ||
408 | local_irq_restore(flags); | |
409 | } | |
410 | #endif /* CONFIG_HIGHMEM */ | |
411 | ||
412 | /* | |
413 | * __dma_sync_page makes memory consistent. identical to __dma_sync, but | |
414 | * takes a struct page instead of a virtual address | |
415 | */ | |
416 | void __dma_sync_page(struct page *page, unsigned long offset, | |
417 | size_t size, int direction) | |
418 | { | |
419 | #ifdef CONFIG_HIGHMEM | |
420 | __dma_sync_page_highmem(page, offset, size, direction); | |
421 | #else | |
422 | unsigned long start = (unsigned long)page_address(page) + offset; | |
423 | __dma_sync((void *)start, size, direction); | |
424 | #endif | |
425 | } | |
426 | EXPORT_SYMBOL(__dma_sync_page); |