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

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

Version: ~ [ linux-5.8-rc3 ] ~ [ linux-5.7.5 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.48 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.129 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.185 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.228 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.228 ] ~ [ 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-3.16.85 ] ~ [ 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-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 #include <asm/dma.h>
 37 
 38 #include "mmu_decl.h"
 39 
 40 /*
 41  * This address range defaults to a value that is safe for all
 42  * platforms which currently set CONFIG_NOT_COHERENT_CACHE. It
 43  * can be further configured for specific applications under
 44  * the "Advanced Setup" menu. -Matt
 45  */
 46 #define CONSISTENT_BASE         (IOREMAP_TOP)
 47 #define CONSISTENT_END          (CONSISTENT_BASE + CONFIG_CONSISTENT_SIZE)
 48 #define CONSISTENT_OFFSET(x)    (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
 49 
 50 /*
 51  * This is the page table (2MB) covering uncached, DMA consistent allocations
 52  */
 53 static DEFINE_SPINLOCK(consistent_lock);
 54 
 55 /*
 56  * VM region handling support.
 57  *
 58  * This should become something generic, handling VM region allocations for
 59  * vmalloc and similar (ioremap, module space, etc).
 60  *
 61  * I envisage vmalloc()'s supporting vm_struct becoming:
 62  *
 63  *  struct vm_struct {
 64  *    struct vm_region  region;
 65  *    unsigned long     flags;
 66  *    struct page       **pages;
 67  *    unsigned int      nr_pages;
 68  *    unsigned long     phys_addr;
 69  *  };
 70  *
 71  * get_vm_area() would then call vm_region_alloc with an appropriate
 72  * struct vm_region head (eg):
 73  *
 74  *  struct vm_region vmalloc_head = {
 75  *      .vm_list        = LIST_HEAD_INIT(vmalloc_head.vm_list),
 76  *      .vm_start       = VMALLOC_START,
 77  *      .vm_end         = VMALLOC_END,
 78  *  };
 79  *
 80  * However, vmalloc_head.vm_start is variable (typically, it is dependent on
 81  * the amount of RAM found at boot time.)  I would imagine that get_vm_area()
 82  * would have to initialise this each time prior to calling vm_region_alloc().
 83  */
 84 struct ppc_vm_region {
 85         struct list_head        vm_list;
 86         unsigned long           vm_start;
 87         unsigned long           vm_end;
 88 };
 89 
 90 static struct ppc_vm_region consistent_head = {
 91         .vm_list        = LIST_HEAD_INIT(consistent_head.vm_list),
 92         .vm_start       = CONSISTENT_BASE,
 93         .vm_end         = CONSISTENT_END,
 94 };
 95 
 96 static struct ppc_vm_region *
 97 ppc_vm_region_alloc(struct ppc_vm_region *head, size_t size, gfp_t gfp)
 98 {
 99         unsigned long addr = head->vm_start, end = head->vm_end - size;
100         unsigned long flags;
101         struct ppc_vm_region *c, *new;
102 
103         new = kmalloc(sizeof(struct ppc_vm_region), gfp);
104         if (!new)
105                 goto out;
106 
107         spin_lock_irqsave(&consistent_lock, flags);
108 
109         list_for_each_entry(c, &head->vm_list, vm_list) {
110                 if ((addr + size) < addr)
111                         goto nospc;
112                 if ((addr + size) <= c->vm_start)
113                         goto found;
114                 addr = c->vm_end;
115                 if (addr > end)
116                         goto nospc;
117         }
118 
119  found:
120         /*
121          * Insert this entry _before_ the one we found.
122          */
123         list_add_tail(&new->vm_list, &c->vm_list);
124         new->vm_start = addr;
125         new->vm_end = addr + size;
126 
127         spin_unlock_irqrestore(&consistent_lock, flags);
128         return new;
129 
130  nospc:
131         spin_unlock_irqrestore(&consistent_lock, flags);
132         kfree(new);
133  out:
134         return NULL;
135 }
136 
137 static struct ppc_vm_region *ppc_vm_region_find(struct ppc_vm_region *head, unsigned long addr)
138 {
139         struct ppc_vm_region *c;
140 
141         list_for_each_entry(c, &head->vm_list, vm_list) {
142                 if (c->vm_start == addr)
143                         goto out;
144         }
145         c = NULL;
146  out:
147         return c;
148 }
149 
150 /*
151  * Allocate DMA-coherent memory space and return both the kernel remapped
152  * virtual and bus address for that space.
153  */
154 void *
155 __dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
156 {
157         struct page *page;
158         struct ppc_vm_region *c;
159         unsigned long order;
160         u64 mask = ISA_DMA_THRESHOLD, limit;
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         size = PAGE_ALIGN(size);
184         limit = (mask + 1) & ~mask;
185         if ((limit && size >= limit) ||
186             size >= (CONSISTENT_END - CONSISTENT_BASE)) {
187                 printk(KERN_WARNING "coherent allocation too big (requested %#x mask %#Lx)\n",
188                        size, mask);
189                 return NULL;
190         }
191 
192         order = get_order(size);
193 
194         /* Might be useful if we ever have a real legacy DMA zone... */
195         if (mask != 0xffffffff)
196                 gfp |= GFP_DMA;
197 
198         page = alloc_pages(gfp, order);
199         if (!page)
200                 goto no_page;
201 
202         /*
203          * Invalidate any data that might be lurking in the
204          * kernel direct-mapped region for device DMA.
205          */
206         {
207                 unsigned long kaddr = (unsigned long)page_address(page);
208                 memset(page_address(page), 0, size);
209                 flush_dcache_range(kaddr, kaddr + size);
210         }
211 
212         /*
213          * Allocate a virtual address in the consistent mapping region.
214          */
215         c = ppc_vm_region_alloc(&consistent_head, size,
216                             gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
217         if (c) {
218                 unsigned long vaddr = c->vm_start;
219                 struct page *end = page + (1 << order);
220 
221                 split_page(page, order);
222 
223                 /*
224                  * Set the "dma handle"
225                  */
226                 *handle = page_to_phys(page);
227 
228                 do {
229                         SetPageReserved(page);
230                         map_page(vaddr, page_to_phys(page),
231                                  pgprot_noncached(PAGE_KERNEL));
232                         page++;
233                         vaddr += PAGE_SIZE;
234                 } while (size -= PAGE_SIZE);
235 
236                 /*
237                  * Free the otherwise unused pages.
238                  */
239                 while (page < end) {
240                         __free_page(page);
241                         page++;
242                 }
243 
244                 return (void *)c->vm_start;
245         }
246 
247         if (page)
248                 __free_pages(page, order);
249  no_page:
250         return NULL;
251 }
252 EXPORT_SYMBOL(__dma_alloc_coherent);
253 
254 /*
255  * free a page as defined by the above mapping.
256  */
257 void __dma_free_coherent(size_t size, void *vaddr)
258 {
259         struct ppc_vm_region *c;
260         unsigned long flags, addr;
261         
262         size = PAGE_ALIGN(size);
263 
264         spin_lock_irqsave(&consistent_lock, flags);
265 
266         c = ppc_vm_region_find(&consistent_head, (unsigned long)vaddr);
267         if (!c)
268                 goto no_area;
269 
270         if ((c->vm_end - c->vm_start) != size) {
271                 printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
272                        __func__, c->vm_end - c->vm_start, size);
273                 dump_stack();
274                 size = c->vm_end - c->vm_start;
275         }
276 
277         addr = c->vm_start;
278         do {
279                 pte_t *ptep;
280                 unsigned long pfn;
281 
282                 ptep = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(addr),
283                                                                addr),
284                                                     addr),
285                                          addr);
286                 if (!pte_none(*ptep) && pte_present(*ptep)) {
287                         pfn = pte_pfn(*ptep);
288                         pte_clear(&init_mm, addr, ptep);
289                         if (pfn_valid(pfn)) {
290                                 struct page *page = pfn_to_page(pfn);
291                                 __free_reserved_page(page);
292                         }
293                 }
294                 addr += PAGE_SIZE;
295         } while (size -= PAGE_SIZE);
296 
297         flush_tlb_kernel_range(c->vm_start, c->vm_end);
298 
299         list_del(&c->vm_list);
300 
301         spin_unlock_irqrestore(&consistent_lock, flags);
302 
303         kfree(c);
304         return;
305 
306  no_area:
307         spin_unlock_irqrestore(&consistent_lock, flags);
308         printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
309                __func__, vaddr);
310         dump_stack();
311 }
312 EXPORT_SYMBOL(__dma_free_coherent);
313 
314 /*
315  * make an area consistent.
316  */
317 void __dma_sync(void *vaddr, size_t size, int direction)
318 {
319         unsigned long start = (unsigned long)vaddr;
320         unsigned long end   = start + size;
321 
322         switch (direction) {
323         case DMA_NONE:
324                 BUG();
325         case DMA_FROM_DEVICE:
326                 /*
327                  * invalidate only when cache-line aligned otherwise there is
328                  * the potential for discarding uncommitted data from the cache
329                  */
330                 if ((start & (L1_CACHE_BYTES - 1)) || (size & (L1_CACHE_BYTES - 1)))
331                         flush_dcache_range(start, end);
332                 else
333                         invalidate_dcache_range(start, end);
334                 break;
335         case DMA_TO_DEVICE:             /* writeback only */
336                 clean_dcache_range(start, end);
337                 break;
338         case DMA_BIDIRECTIONAL: /* writeback and invalidate */
339                 flush_dcache_range(start, end);
340                 break;
341         }
342 }
343 EXPORT_SYMBOL(__dma_sync);
344 
345 #ifdef CONFIG_HIGHMEM
346 /*
347  * __dma_sync_page() implementation for systems using highmem.
348  * In this case, each page of a buffer must be kmapped/kunmapped
349  * in order to have a virtual address for __dma_sync(). This must
350  * not sleep so kmap_atomic()/kunmap_atomic() are used.
351  *
352  * Note: yes, it is possible and correct to have a buffer extend
353  * beyond the first page.
354  */
355 static inline void __dma_sync_page_highmem(struct page *page,
356                 unsigned long offset, size_t size, int direction)
357 {
358         size_t seg_size = min((size_t)(PAGE_SIZE - offset), size);
359         size_t cur_size = seg_size;
360         unsigned long flags, start, seg_offset = offset;
361         int nr_segs = 1 + ((size - seg_size) + PAGE_SIZE - 1)/PAGE_SIZE;
362         int seg_nr = 0;
363 
364         local_irq_save(flags);
365 
366         do {
367                 start = (unsigned long)kmap_atomic(page + seg_nr) + seg_offset;
368 
369                 /* Sync this buffer segment */
370                 __dma_sync((void *)start, seg_size, direction);
371                 kunmap_atomic((void *)start);
372                 seg_nr++;
373 
374                 /* Calculate next buffer segment size */
375                 seg_size = min((size_t)PAGE_SIZE, size - cur_size);
376 
377                 /* Add the segment size to our running total */
378                 cur_size += seg_size;
379                 seg_offset = 0;
380         } while (seg_nr < nr_segs);
381 
382         local_irq_restore(flags);
383 }
384 #endif /* CONFIG_HIGHMEM */
385 
386 /*
387  * __dma_sync_page makes memory consistent. identical to __dma_sync, but
388  * takes a struct page instead of a virtual address
389  */
390 void __dma_sync_page(struct page *page, unsigned long offset,
391         size_t size, int direction)
392 {
393 #ifdef CONFIG_HIGHMEM
394         __dma_sync_page_highmem(page, offset, size, direction);
395 #else
396         unsigned long start = (unsigned long)page_address(page) + offset;
397         __dma_sync((void *)start, size, direction);
398 #endif
399 }
400 EXPORT_SYMBOL(__dma_sync_page);
401 
402 /*
403  * Return the PFN for a given cpu virtual address returned by
404  * __dma_alloc_coherent. This is used by dma_mmap_coherent()
405  */
406 unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr)
407 {
408         /* This should always be populated, so we don't test every
409          * level. If that fails, we'll have a nice crash which
410          * will be as good as a BUG_ON()
411          */
412         pgd_t *pgd = pgd_offset_k(cpu_addr);
413         pud_t *pud = pud_offset(pgd, cpu_addr);
414         pmd_t *pmd = pmd_offset(pud, cpu_addr);
415         pte_t *ptep = pte_offset_kernel(pmd, cpu_addr);
416 
417         if (pte_none(*ptep) || !pte_present(*ptep))
418                 return 0;
419         return pte_pfn(*ptep);
420 }
421 

~ [ 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