~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/powerpc/mm/dma-noncoherent.c

Version: ~ [ linux-5.5-rc1 ] ~ [ linux-5.4.2 ] ~ [ linux-5.3.15 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.88 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.158 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.206 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.206 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 
 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 /*
 40  * This address range defaults to a value that is safe for all
 41  * platforms which currently set CONFIG_NOT_COHERENT_CACHE. It
 42  * can be further configured for specific applications under
 43  * the "Advanced Setup" menu. -Matt
 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  * This is the page table (2MB) covering uncached, DMA consistent allocations
 51  */
 52 static DEFINE_SPINLOCK(consistent_lock);
 53 
 54 /*
 55  * VM region handling support.
 56  *
 57  * This should become something generic, handling VM region allocations for
 58  * vmalloc and similar (ioremap, module space, etc).
 59  *
 60  * I envisage vmalloc()'s supporting vm_struct becoming:
 61  *
 62  *  struct vm_struct {
 63  *    struct vm_region  region;
 64  *    unsigned long     flags;
 65  *    struct page       **pages;
 66  *    unsigned int      nr_pages;
 67  *    unsigned long     phys_addr;
 68  *  };
 69  *
 70  * get_vm_area() would then call vm_region_alloc with an appropriate
 71  * struct vm_region head (eg):
 72  *
 73  *  struct vm_region vmalloc_head = {
 74  *      .vm_list        = LIST_HEAD_INIT(vmalloc_head.vm_list),
 75  *      .vm_start       = VMALLOC_START,
 76  *      .vm_end         = VMALLOC_END,
 77  *  };
 78  *
 79  * However, vmalloc_head.vm_start is variable (typically, it is dependent on
 80  * the amount of RAM found at boot time.)  I would imagine that get_vm_area()
 81  * would have to initialise this each time prior to calling vm_region_alloc().
 82  */
 83 struct ppc_vm_region {
 84         struct list_head        vm_list;
 85         unsigned long           vm_start;
 86         unsigned long           vm_end;
 87 };
 88 
 89 static 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 
 95 static struct ppc_vm_region *
 96 ppc_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          * Insert this entry _before_ the one we found.
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 
136 static 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  * Allocate DMA-coherent memory space and return both the kernel remapped
151  * virtual and bus address for that space.
152  */
153 void *
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                  * Sanity check the DMA mask - it must be non-zero, and
166                  * must be able to be satisfied by a DMA allocation.
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         /* Might be useful if we ever have a real legacy DMA zone... */
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          * Invalidate any data that might be lurking in the
203          * kernel direct-mapped region for device DMA.
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          * Allocate a virtual address in the consistent mapping region.
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                  * Set the "dma handle"
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                  * Free the otherwise unused pages.
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 }
251 EXPORT_SYMBOL(__dma_alloc_coherent);
252 
253 /*
254  * free a page as defined by the above mapping.
255  */
256 void __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 }
313 EXPORT_SYMBOL(__dma_free_coherent);
314 
315 /*
316  * make an area consistent.
317  */
318 void __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                  * invalidate only when cache-line aligned otherwise there is
329                  * the potential for discarding uncommitted data from the cache
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:             /* writeback only */
337                 clean_dcache_range(start, end);
338                 break;
339         case DMA_BIDIRECTIONAL: /* writeback and invalidate */
340                 flush_dcache_range(start, end);
341                 break;
342         }
343 }
344 EXPORT_SYMBOL(__dma_sync);
345 
346 #ifdef CONFIG_HIGHMEM
347 /*
348  * __dma_sync_page() implementation for systems using highmem.
349  * In this case, each page of a buffer must be kmapped/kunmapped
350  * in order to have a virtual address for __dma_sync(). This must
351  * not sleep so kmap_atomic()/kunmap_atomic() are used.
352  *
353  * Note: yes, it is possible and correct to have a buffer extend
354  * beyond the first page.
355  */
356 static 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                 /* Sync this buffer segment */
371                 __dma_sync((void *)start, seg_size, direction);
372                 kunmap_atomic((void *)start);
373                 seg_nr++;
374 
375                 /* Calculate next buffer segment size */
376                 seg_size = min((size_t)PAGE_SIZE, size - cur_size);
377 
378                 /* Add the segment size to our running total */
379                 cur_size += seg_size;
380                 seg_offset = 0;
381         } while (seg_nr < nr_segs);
382 
383         local_irq_restore(flags);
384 }
385 #endif /* CONFIG_HIGHMEM */
386 
387 /*
388  * __dma_sync_page makes memory consistent. identical to __dma_sync, but
389  * takes a struct page instead of a virtual address
390  */
391 void __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 }
401 EXPORT_SYMBOL(__dma_sync_page);
402 
403 /*
404  * Return the PFN for a given cpu virtual address returned by
405  * __dma_alloc_coherent. This is used by dma_mmap_coherent()
406  */
407 unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr)
408 {
409         /* This should always be populated, so we don't test every
410          * level. If that fails, we'll have a nice crash which
411          * will be as good as a BUG_ON()
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 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp