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25#include <linux/sched.h>
26#include <linux/slab.h>
27#include <linux/kernel.h>
28#include <linux/errno.h>
29#include <linux/string.h>
30#include <linux/types.h>
31#include <linux/highmem.h>
32#include <linux/dma-mapping.h>
33#include <linux/export.h>
34
35#include <asm/tlbflush.h>
36
37#include "mmu_decl.h"
38
39
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42
43
44
45#define CONSISTENT_BASE (IOREMAP_TOP)
46#define CONSISTENT_END (CONSISTENT_BASE + CONFIG_CONSISTENT_SIZE)
47#define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
48
49
50
51
52static DEFINE_SPINLOCK(consistent_lock);
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83struct ppc_vm_region {
84 struct list_head vm_list;
85 unsigned long vm_start;
86 unsigned long vm_end;
87};
88
89static struct ppc_vm_region consistent_head = {
90 .vm_list = LIST_HEAD_INIT(consistent_head.vm_list),
91 .vm_start = CONSISTENT_BASE,
92 .vm_end = CONSISTENT_END,
93};
94
95static struct ppc_vm_region *
96ppc_vm_region_alloc(struct ppc_vm_region *head, size_t size, gfp_t gfp)
97{
98 unsigned long addr = head->vm_start, end = head->vm_end - size;
99 unsigned long flags;
100 struct ppc_vm_region *c, *new;
101
102 new = kmalloc(sizeof(struct ppc_vm_region), gfp);
103 if (!new)
104 goto out;
105
106 spin_lock_irqsave(&consistent_lock, flags);
107
108 list_for_each_entry(c, &head->vm_list, vm_list) {
109 if ((addr + size) < addr)
110 goto nospc;
111 if ((addr + size) <= c->vm_start)
112 goto found;
113 addr = c->vm_end;
114 if (addr > end)
115 goto nospc;
116 }
117
118 found:
119
120
121
122 list_add_tail(&new->vm_list, &c->vm_list);
123 new->vm_start = addr;
124 new->vm_end = addr + size;
125
126 spin_unlock_irqrestore(&consistent_lock, flags);
127 return new;
128
129 nospc:
130 spin_unlock_irqrestore(&consistent_lock, flags);
131 kfree(new);
132 out:
133 return NULL;
134}
135
136static struct ppc_vm_region *ppc_vm_region_find(struct ppc_vm_region *head, unsigned long addr)
137{
138 struct ppc_vm_region *c;
139
140 list_for_each_entry(c, &head->vm_list, vm_list) {
141 if (c->vm_start == addr)
142 goto out;
143 }
144 c = NULL;
145 out:
146 return c;
147}
148
149
150
151
152
153void *
154__dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
155{
156 struct page *page;
157 struct ppc_vm_region *c;
158 unsigned long order;
159 u64 mask = ISA_DMA_THRESHOLD, limit;
160
161 if (dev) {
162 mask = dev->coherent_dma_mask;
163
164
165
166
167
168 if (mask == 0) {
169 dev_warn(dev, "coherent DMA mask is unset\n");
170 goto no_page;
171 }
172
173 if ((~mask) & ISA_DMA_THRESHOLD) {
174 dev_warn(dev, "coherent DMA mask %#llx is smaller "
175 "than system GFP_DMA mask %#llx\n",
176 mask, (unsigned long long)ISA_DMA_THRESHOLD);
177 goto no_page;
178 }
179 }
180
181
182 size = PAGE_ALIGN(size);
183 limit = (mask + 1) & ~mask;
184 if ((limit && size >= limit) ||
185 size >= (CONSISTENT_END - CONSISTENT_BASE)) {
186 printk(KERN_WARNING "coherent allocation too big (requested %#x mask %#Lx)\n",
187 size, mask);
188 return NULL;
189 }
190
191 order = get_order(size);
192
193
194 if (mask != 0xffffffff)
195 gfp |= GFP_DMA;
196
197 page = alloc_pages(gfp, order);
198 if (!page)
199 goto no_page;
200
201
202
203
204
205 {
206 unsigned long kaddr = (unsigned long)page_address(page);
207 memset(page_address(page), 0, size);
208 flush_dcache_range(kaddr, kaddr + size);
209 }
210
211
212
213
214 c = ppc_vm_region_alloc(&consistent_head, size,
215 gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
216 if (c) {
217 unsigned long vaddr = c->vm_start;
218 struct page *end = page + (1 << order);
219
220 split_page(page, order);
221
222
223
224
225 *handle = page_to_phys(page);
226
227 do {
228 SetPageReserved(page);
229 map_page(vaddr, page_to_phys(page),
230 pgprot_noncached(PAGE_KERNEL));
231 page++;
232 vaddr += PAGE_SIZE;
233 } while (size -= PAGE_SIZE);
234
235
236
237
238 while (page < end) {
239 __free_page(page);
240 page++;
241 }
242
243 return (void *)c->vm_start;
244 }
245
246 if (page)
247 __free_pages(page, order);
248 no_page:
249 return NULL;
250}
251EXPORT_SYMBOL(__dma_alloc_coherent);
252
253
254
255
256void __dma_free_coherent(size_t size, void *vaddr)
257{
258 struct ppc_vm_region *c;
259 unsigned long flags, addr;
260
261 size = PAGE_ALIGN(size);
262
263 spin_lock_irqsave(&consistent_lock, flags);
264
265 c = ppc_vm_region_find(&consistent_head, (unsigned long)vaddr);
266 if (!c)
267 goto no_area;
268
269 if ((c->vm_end - c->vm_start) != size) {
270 printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
271 __func__, c->vm_end - c->vm_start, size);
272 dump_stack();
273 size = c->vm_end - c->vm_start;
274 }
275
276 addr = c->vm_start;
277 do {
278 pte_t *ptep;
279 unsigned long pfn;
280
281 ptep = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(addr),
282 addr),
283 addr),
284 addr);
285 if (!pte_none(*ptep) && pte_present(*ptep)) {
286 pfn = pte_pfn(*ptep);
287 pte_clear(&init_mm, addr, ptep);
288 if (pfn_valid(pfn)) {
289 struct page *page = pfn_to_page(pfn);
290
291 ClearPageReserved(page);
292 __free_page(page);
293 }
294 }
295 addr += PAGE_SIZE;
296 } while (size -= PAGE_SIZE);
297
298 flush_tlb_kernel_range(c->vm_start, c->vm_end);
299
300 list_del(&c->vm_list);
301
302 spin_unlock_irqrestore(&consistent_lock, flags);
303
304 kfree(c);
305 return;
306
307 no_area:
308 spin_unlock_irqrestore(&consistent_lock, flags);
309 printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
310 __func__, vaddr);
311 dump_stack();
312}
313EXPORT_SYMBOL(__dma_free_coherent);
314
315
316
317
318void __dma_sync(void *vaddr, size_t size, int direction)
319{
320 unsigned long start = (unsigned long)vaddr;
321 unsigned long end = start + size;
322
323 switch (direction) {
324 case DMA_NONE:
325 BUG();
326 case DMA_FROM_DEVICE:
327
328
329
330
331 if ((start & (L1_CACHE_BYTES - 1)) || (size & (L1_CACHE_BYTES - 1)))
332 flush_dcache_range(start, end);
333 else
334 invalidate_dcache_range(start, end);
335 break;
336 case DMA_TO_DEVICE:
337 clean_dcache_range(start, end);
338 break;
339 case DMA_BIDIRECTIONAL:
340 flush_dcache_range(start, end);
341 break;
342 }
343}
344EXPORT_SYMBOL(__dma_sync);
345
346#ifdef CONFIG_HIGHMEM
347
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354
355
356static inline void __dma_sync_page_highmem(struct page *page,
357 unsigned long offset, size_t size, int direction)
358{
359 size_t seg_size = min((size_t)(PAGE_SIZE - offset), size);
360 size_t cur_size = seg_size;
361 unsigned long flags, start, seg_offset = offset;
362 int nr_segs = 1 + ((size - seg_size) + PAGE_SIZE - 1)/PAGE_SIZE;
363 int seg_nr = 0;
364
365 local_irq_save(flags);
366
367 do {
368 start = (unsigned long)kmap_atomic(page + seg_nr) + seg_offset;
369
370
371 __dma_sync((void *)start, seg_size, direction);
372 kunmap_atomic((void *)start);
373 seg_nr++;
374
375
376 seg_size = min((size_t)PAGE_SIZE, size - cur_size);
377
378
379 cur_size += seg_size;
380 seg_offset = 0;
381 } while (seg_nr < nr_segs);
382
383 local_irq_restore(flags);
384}
385#endif
386
387
388
389
390
391void __dma_sync_page(struct page *page, unsigned long offset,
392 size_t size, int direction)
393{
394#ifdef CONFIG_HIGHMEM
395 __dma_sync_page_highmem(page, offset, size, direction);
396#else
397 unsigned long start = (unsigned long)page_address(page) + offset;
398 __dma_sync((void *)start, size, direction);
399#endif
400}
401EXPORT_SYMBOL(__dma_sync_page);
402
403
404
405
406
407unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr)
408{
409
410
411
412
413 pgd_t *pgd = pgd_offset_k(cpu_addr);
414 pud_t *pud = pud_offset(pgd, cpu_addr);
415 pmd_t *pmd = pmd_offset(pud, cpu_addr);
416 pte_t *ptep = pte_offset_kernel(pmd, cpu_addr);
417
418 if (pte_none(*ptep) || !pte_present(*ptep))
419 return 0;
420 return pte_pfn(*ptep);
421}
422