xref: /openbmc/linux/arch/parisc/kernel/pci-dma.c (revision 87c2ce3b)
1 /*
2 ** PARISC 1.1 Dynamic DMA mapping support.
3 ** This implementation is for PA-RISC platforms that do not support
4 ** I/O TLBs (aka DMA address translation hardware).
5 ** See Documentation/DMA-mapping.txt for interface definitions.
6 **
7 **      (c) Copyright 1999,2000 Hewlett-Packard Company
8 **      (c) Copyright 2000 Grant Grundler
9 **	(c) Copyright 2000 Philipp Rumpf <prumpf@tux.org>
10 **      (c) Copyright 2000 John Marvin
11 **
12 ** "leveraged" from 2.3.47: arch/ia64/kernel/pci-dma.c.
13 ** (I assume it's from David Mosberger-Tang but there was no Copyright)
14 **
15 ** AFAIK, all PA7100LC and PA7300LC platforms can use this code.
16 **
17 ** - ggg
18 */
19 
20 #include <linux/init.h>
21 #include <linux/mm.h>
22 #include <linux/pci.h>
23 #include <linux/proc_fs.h>
24 #include <linux/slab.h>
25 #include <linux/string.h>
26 #include <linux/types.h>
27 
28 #include <asm/cacheflush.h>
29 #include <asm/dma.h>    /* for DMA_CHUNK_SIZE */
30 #include <asm/io.h>
31 #include <asm/page.h>	/* get_order */
32 #include <asm/pgalloc.h>
33 #include <asm/uaccess.h>
34 #include <asm/tlbflush.h>	/* for purge_tlb_*() macros */
35 
36 static struct proc_dir_entry * proc_gsc_root = NULL;
37 static int pcxl_proc_info(char *buffer, char **start, off_t offset, int length);
38 static unsigned long pcxl_used_bytes = 0;
39 static unsigned long pcxl_used_pages = 0;
40 
41 extern unsigned long pcxl_dma_start; /* Start of pcxl dma mapping area */
42 static spinlock_t   pcxl_res_lock;
43 static char    *pcxl_res_map;
44 static int     pcxl_res_hint;
45 static int     pcxl_res_size;
46 
47 #ifdef DEBUG_PCXL_RESOURCE
48 #define DBG_RES(x...)	printk(x)
49 #else
50 #define DBG_RES(x...)
51 #endif
52 
53 
54 /*
55 ** Dump a hex representation of the resource map.
56 */
57 
58 #ifdef DUMP_RESMAP
59 static
60 void dump_resmap(void)
61 {
62 	u_long *res_ptr = (unsigned long *)pcxl_res_map;
63 	u_long i = 0;
64 
65 	printk("res_map: ");
66 	for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr)
67 		printk("%08lx ", *res_ptr);
68 
69 	printk("\n");
70 }
71 #else
72 static inline void dump_resmap(void) {;}
73 #endif
74 
75 static int pa11_dma_supported( struct device *dev, u64 mask)
76 {
77 	return 1;
78 }
79 
80 static inline int map_pte_uncached(pte_t * pte,
81 		unsigned long vaddr,
82 		unsigned long size, unsigned long *paddr_ptr)
83 {
84 	unsigned long end;
85 	unsigned long orig_vaddr = vaddr;
86 
87 	vaddr &= ~PMD_MASK;
88 	end = vaddr + size;
89 	if (end > PMD_SIZE)
90 		end = PMD_SIZE;
91 	do {
92 		if (!pte_none(*pte))
93 			printk(KERN_ERR "map_pte_uncached: page already exists\n");
94 		set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
95 		purge_tlb_start();
96 		pdtlb_kernel(orig_vaddr);
97 		purge_tlb_end();
98 		vaddr += PAGE_SIZE;
99 		orig_vaddr += PAGE_SIZE;
100 		(*paddr_ptr) += PAGE_SIZE;
101 		pte++;
102 	} while (vaddr < end);
103 	return 0;
104 }
105 
106 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
107 		unsigned long size, unsigned long *paddr_ptr)
108 {
109 	unsigned long end;
110 	unsigned long orig_vaddr = vaddr;
111 
112 	vaddr &= ~PGDIR_MASK;
113 	end = vaddr + size;
114 	if (end > PGDIR_SIZE)
115 		end = PGDIR_SIZE;
116 	do {
117 		pte_t * pte = pte_alloc_kernel(pmd, vaddr);
118 		if (!pte)
119 			return -ENOMEM;
120 		if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr))
121 			return -ENOMEM;
122 		vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
123 		orig_vaddr += PMD_SIZE;
124 		pmd++;
125 	} while (vaddr < end);
126 	return 0;
127 }
128 
129 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,
130 		unsigned long paddr)
131 {
132 	pgd_t * dir;
133 	unsigned long end = vaddr + size;
134 
135 	dir = pgd_offset_k(vaddr);
136 	do {
137 		pmd_t *pmd;
138 
139 		pmd = pmd_alloc(NULL, dir, vaddr);
140 		if (!pmd)
141 			return -ENOMEM;
142 		if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr))
143 			return -ENOMEM;
144 		vaddr = vaddr + PGDIR_SIZE;
145 		dir++;
146 	} while (vaddr && (vaddr < end));
147 	return 0;
148 }
149 
150 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
151 		unsigned long size)
152 {
153 	pte_t * pte;
154 	unsigned long end;
155 	unsigned long orig_vaddr = vaddr;
156 
157 	if (pmd_none(*pmd))
158 		return;
159 	if (pmd_bad(*pmd)) {
160 		pmd_ERROR(*pmd);
161 		pmd_clear(pmd);
162 		return;
163 	}
164 	pte = pte_offset_map(pmd, vaddr);
165 	vaddr &= ~PMD_MASK;
166 	end = vaddr + size;
167 	if (end > PMD_SIZE)
168 		end = PMD_SIZE;
169 	do {
170 		pte_t page = *pte;
171 		pte_clear(&init_mm, vaddr, pte);
172 		purge_tlb_start();
173 		pdtlb_kernel(orig_vaddr);
174 		purge_tlb_end();
175 		vaddr += PAGE_SIZE;
176 		orig_vaddr += PAGE_SIZE;
177 		pte++;
178 		if (pte_none(page) || pte_present(page))
179 			continue;
180 		printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
181 	} while (vaddr < end);
182 }
183 
184 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr,
185 		unsigned long size)
186 {
187 	pmd_t * pmd;
188 	unsigned long end;
189 	unsigned long orig_vaddr = vaddr;
190 
191 	if (pgd_none(*dir))
192 		return;
193 	if (pgd_bad(*dir)) {
194 		pgd_ERROR(*dir);
195 		pgd_clear(dir);
196 		return;
197 	}
198 	pmd = pmd_offset(dir, vaddr);
199 	vaddr &= ~PGDIR_MASK;
200 	end = vaddr + size;
201 	if (end > PGDIR_SIZE)
202 		end = PGDIR_SIZE;
203 	do {
204 		unmap_uncached_pte(pmd, orig_vaddr, end - vaddr);
205 		vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
206 		orig_vaddr += PMD_SIZE;
207 		pmd++;
208 	} while (vaddr < end);
209 }
210 
211 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size)
212 {
213 	pgd_t * dir;
214 	unsigned long end = vaddr + size;
215 
216 	dir = pgd_offset_k(vaddr);
217 	do {
218 		unmap_uncached_pmd(dir, vaddr, end - vaddr);
219 		vaddr = vaddr + PGDIR_SIZE;
220 		dir++;
221 	} while (vaddr && (vaddr < end));
222 }
223 
224 #define PCXL_SEARCH_LOOP(idx, mask, size)  \
225        for(; res_ptr < res_end; ++res_ptr) \
226        { \
227                if(0 == ((*res_ptr) & mask)) { \
228                        *res_ptr |= mask; \
229 		       idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \
230 		       pcxl_res_hint = idx + (size >> 3); \
231                        goto resource_found; \
232                } \
233        }
234 
235 #define PCXL_FIND_FREE_MAPPING(idx, mask, size)  { \
236        u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \
237        u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \
238        PCXL_SEARCH_LOOP(idx, mask, size); \
239        res_ptr = (u##size *)&pcxl_res_map[0]; \
240        PCXL_SEARCH_LOOP(idx, mask, size); \
241 }
242 
243 unsigned long
244 pcxl_alloc_range(size_t size)
245 {
246 	int res_idx;
247 	u_long mask, flags;
248 	unsigned int pages_needed = size >> PAGE_SHIFT;
249 
250 	mask = (u_long) -1L;
251  	mask >>= BITS_PER_LONG - pages_needed;
252 
253 	DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n",
254 		size, pages_needed, mask);
255 
256 	spin_lock_irqsave(&pcxl_res_lock, flags);
257 
258 	if(pages_needed <= 8) {
259 		PCXL_FIND_FREE_MAPPING(res_idx, mask, 8);
260 	} else if(pages_needed <= 16) {
261 		PCXL_FIND_FREE_MAPPING(res_idx, mask, 16);
262 	} else if(pages_needed <= 32) {
263 		PCXL_FIND_FREE_MAPPING(res_idx, mask, 32);
264 	} else {
265 		panic("%s: pcxl_alloc_range() Too many pages to map.\n",
266 		      __FILE__);
267 	}
268 
269 	dump_resmap();
270 	panic("%s: pcxl_alloc_range() out of dma mapping resources\n",
271 	      __FILE__);
272 
273 resource_found:
274 
275 	DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n",
276 		res_idx, mask, pcxl_res_hint);
277 
278 	pcxl_used_pages += pages_needed;
279 	pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1);
280 
281 	spin_unlock_irqrestore(&pcxl_res_lock, flags);
282 
283 	dump_resmap();
284 
285 	/*
286 	** return the corresponding vaddr in the pcxl dma map
287 	*/
288 	return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3)));
289 }
290 
291 #define PCXL_FREE_MAPPINGS(idx, m, size) \
292 		u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \
293 		/* BUG_ON((*res_ptr & m) != m); */ \
294 		*res_ptr &= ~m;
295 
296 /*
297 ** clear bits in the pcxl resource map
298 */
299 static void
300 pcxl_free_range(unsigned long vaddr, size_t size)
301 {
302 	u_long mask, flags;
303 	unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3);
304 	unsigned int pages_mapped = size >> PAGE_SHIFT;
305 
306 	mask = (u_long) -1L;
307  	mask >>= BITS_PER_LONG - pages_mapped;
308 
309 	DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n",
310 		res_idx, size, pages_mapped, mask);
311 
312 	spin_lock_irqsave(&pcxl_res_lock, flags);
313 
314 	if(pages_mapped <= 8) {
315 		PCXL_FREE_MAPPINGS(res_idx, mask, 8);
316 	} else if(pages_mapped <= 16) {
317 		PCXL_FREE_MAPPINGS(res_idx, mask, 16);
318 	} else if(pages_mapped <= 32) {
319 		PCXL_FREE_MAPPINGS(res_idx, mask, 32);
320 	} else {
321 		panic("%s: pcxl_free_range() Too many pages to unmap.\n",
322 		      __FILE__);
323 	}
324 
325 	pcxl_used_pages -= (pages_mapped ? pages_mapped : 1);
326 	pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1);
327 
328 	spin_unlock_irqrestore(&pcxl_res_lock, flags);
329 
330 	dump_resmap();
331 }
332 
333 static int __init
334 pcxl_dma_init(void)
335 {
336 	if (pcxl_dma_start == 0)
337 		return 0;
338 
339 	spin_lock_init(&pcxl_res_lock);
340 	pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3);
341 	pcxl_res_hint = 0;
342 	pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL,
343 					    get_order(pcxl_res_size));
344 	memset(pcxl_res_map, 0, pcxl_res_size);
345 	proc_gsc_root = proc_mkdir("gsc", 0);
346 	if (!proc_gsc_root)
347     		printk(KERN_WARNING
348 			"pcxl_dma_init: Unable to create gsc /proc dir entry\n");
349 	else {
350 		struct proc_dir_entry* ent;
351 		ent = create_proc_info_entry("pcxl_dma", 0,
352 				proc_gsc_root, pcxl_proc_info);
353 		if (!ent)
354 			printk(KERN_WARNING
355 				"pci-dma.c: Unable to create pcxl_dma /proc entry.\n");
356 	}
357 	return 0;
358 }
359 
360 __initcall(pcxl_dma_init);
361 
362 static void * pa11_dma_alloc_consistent (struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag)
363 {
364 	unsigned long vaddr;
365 	unsigned long paddr;
366 	int order;
367 
368 	order = get_order(size);
369 	size = 1 << (order + PAGE_SHIFT);
370 	vaddr = pcxl_alloc_range(size);
371 	paddr = __get_free_pages(flag, order);
372 	flush_kernel_dcache_range(paddr, size);
373 	paddr = __pa(paddr);
374 	map_uncached_pages(vaddr, size, paddr);
375 	*dma_handle = (dma_addr_t) paddr;
376 
377 #if 0
378 /* This probably isn't needed to support EISA cards.
379 ** ISA cards will certainly only support 24-bit DMA addressing.
380 ** Not clear if we can, want, or need to support ISA.
381 */
382 	if (!dev || *dev->coherent_dma_mask < 0xffffffff)
383 		gfp |= GFP_DMA;
384 #endif
385 	return (void *)vaddr;
386 }
387 
388 static void pa11_dma_free_consistent (struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle)
389 {
390 	int order;
391 
392 	order = get_order(size);
393 	size = 1 << (order + PAGE_SHIFT);
394 	unmap_uncached_pages((unsigned long)vaddr, size);
395 	pcxl_free_range((unsigned long)vaddr, size);
396 	free_pages((unsigned long)__va(dma_handle), order);
397 }
398 
399 static dma_addr_t pa11_dma_map_single(struct device *dev, void *addr, size_t size, enum dma_data_direction direction)
400 {
401 	if (direction == DMA_NONE) {
402 		printk(KERN_ERR "pa11_dma_map_single(PCI_DMA_NONE) called by %p\n", __builtin_return_address(0));
403 		BUG();
404 	}
405 
406 	flush_kernel_dcache_range((unsigned long) addr, size);
407 	return virt_to_phys(addr);
408 }
409 
410 static void pa11_dma_unmap_single(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
411 {
412 	if (direction == DMA_NONE) {
413 		printk(KERN_ERR "pa11_dma_unmap_single(PCI_DMA_NONE) called by %p\n", __builtin_return_address(0));
414 		BUG();
415 	}
416 
417 	if (direction == DMA_TO_DEVICE)
418 	    return;
419 
420 	/*
421 	 * For PCI_DMA_FROMDEVICE this flush is not necessary for the
422 	 * simple map/unmap case. However, it IS necessary if if
423 	 * pci_dma_sync_single_* has been called and the buffer reused.
424 	 */
425 
426 	flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle), size);
427 	return;
428 }
429 
430 static int pa11_dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
431 {
432 	int i;
433 
434 	if (direction == DMA_NONE)
435 	    BUG();
436 
437 	for (i = 0; i < nents; i++, sglist++ ) {
438 		unsigned long vaddr = sg_virt_addr(sglist);
439 		sg_dma_address(sglist) = (dma_addr_t) virt_to_phys(vaddr);
440 		sg_dma_len(sglist) = sglist->length;
441 		flush_kernel_dcache_range(vaddr, sglist->length);
442 	}
443 	return nents;
444 }
445 
446 static void pa11_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
447 {
448 	int i;
449 
450 	if (direction == DMA_NONE)
451 	    BUG();
452 
453 	if (direction == DMA_TO_DEVICE)
454 	    return;
455 
456 	/* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
457 
458 	for (i = 0; i < nents; i++, sglist++ )
459 		flush_kernel_dcache_range(sg_virt_addr(sglist), sglist->length);
460 	return;
461 }
462 
463 static void pa11_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, unsigned long offset, size_t size, enum dma_data_direction direction)
464 {
465 	if (direction == DMA_NONE)
466 	    BUG();
467 
468 	flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle) + offset, size);
469 }
470 
471 static void pa11_dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, unsigned long offset, size_t size, enum dma_data_direction direction)
472 {
473 	if (direction == DMA_NONE)
474 	    BUG();
475 
476 	flush_kernel_dcache_range((unsigned long) phys_to_virt(dma_handle) + offset, size);
477 }
478 
479 static void pa11_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
480 {
481 	int i;
482 
483 	/* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
484 
485 	for (i = 0; i < nents; i++, sglist++ )
486 		flush_kernel_dcache_range(sg_virt_addr(sglist), sglist->length);
487 }
488 
489 static void pa11_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist, int nents, enum dma_data_direction direction)
490 {
491 	int i;
492 
493 	/* once we do combining we'll need to use phys_to_virt(sg_dma_address(sglist)) */
494 
495 	for (i = 0; i < nents; i++, sglist++ )
496 		flush_kernel_dcache_range(sg_virt_addr(sglist), sglist->length);
497 }
498 
499 struct hppa_dma_ops pcxl_dma_ops = {
500 	.dma_supported =	pa11_dma_supported,
501 	.alloc_consistent =	pa11_dma_alloc_consistent,
502 	.alloc_noncoherent =	pa11_dma_alloc_consistent,
503 	.free_consistent =	pa11_dma_free_consistent,
504 	.map_single =		pa11_dma_map_single,
505 	.unmap_single =		pa11_dma_unmap_single,
506 	.map_sg =		pa11_dma_map_sg,
507 	.unmap_sg =		pa11_dma_unmap_sg,
508 	.dma_sync_single_for_cpu = pa11_dma_sync_single_for_cpu,
509 	.dma_sync_single_for_device = pa11_dma_sync_single_for_device,
510 	.dma_sync_sg_for_cpu = pa11_dma_sync_sg_for_cpu,
511 	.dma_sync_sg_for_device = pa11_dma_sync_sg_for_device,
512 };
513 
514 static void *fail_alloc_consistent(struct device *dev, size_t size,
515 				   dma_addr_t *dma_handle, gfp_t flag)
516 {
517 	return NULL;
518 }
519 
520 static void *pa11_dma_alloc_noncoherent(struct device *dev, size_t size,
521 					  dma_addr_t *dma_handle, gfp_t flag)
522 {
523 	void *addr = NULL;
524 
525 	/* rely on kmalloc to be cacheline aligned */
526 	addr = kmalloc(size, flag);
527 	if(addr)
528 		*dma_handle = (dma_addr_t)virt_to_phys(addr);
529 
530 	return addr;
531 }
532 
533 static void pa11_dma_free_noncoherent(struct device *dev, size_t size,
534 					void *vaddr, dma_addr_t iova)
535 {
536 	kfree(vaddr);
537 	return;
538 }
539 
540 struct hppa_dma_ops pcx_dma_ops = {
541 	.dma_supported =	pa11_dma_supported,
542 	.alloc_consistent =	fail_alloc_consistent,
543 	.alloc_noncoherent =	pa11_dma_alloc_noncoherent,
544 	.free_consistent =	pa11_dma_free_noncoherent,
545 	.map_single =		pa11_dma_map_single,
546 	.unmap_single =		pa11_dma_unmap_single,
547 	.map_sg =		pa11_dma_map_sg,
548 	.unmap_sg =		pa11_dma_unmap_sg,
549 	.dma_sync_single_for_cpu =	pa11_dma_sync_single_for_cpu,
550 	.dma_sync_single_for_device =	pa11_dma_sync_single_for_device,
551 	.dma_sync_sg_for_cpu =		pa11_dma_sync_sg_for_cpu,
552 	.dma_sync_sg_for_device =	pa11_dma_sync_sg_for_device,
553 };
554 
555 
556 static int pcxl_proc_info(char *buf, char **start, off_t offset, int len)
557 {
558 #if 0
559 	u_long i = 0;
560 	unsigned long *res_ptr = (u_long *)pcxl_res_map;
561 #endif
562 	unsigned long total_pages = pcxl_res_size << 3;   /* 8 bits per byte */
563 
564 	sprintf(buf, "\nDMA Mapping Area size    : %d bytes (%ld pages)\n",
565 		PCXL_DMA_MAP_SIZE, total_pages);
566 
567 	sprintf(buf, "%sResource bitmap : %d bytes\n", buf, pcxl_res_size);
568 
569 	strcat(buf,  "     	  total:    free:    used:   % used:\n");
570 	sprintf(buf, "%sblocks  %8d %8ld %8ld %8ld%%\n", buf, pcxl_res_size,
571 		pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes,
572 		(pcxl_used_bytes * 100) / pcxl_res_size);
573 
574 	sprintf(buf, "%spages   %8ld %8ld %8ld %8ld%%\n", buf, total_pages,
575 		total_pages - pcxl_used_pages, pcxl_used_pages,
576 		(pcxl_used_pages * 100 / total_pages));
577 
578 #if 0
579 	strcat(buf, "\nResource bitmap:");
580 
581 	for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) {
582 		if ((i & 7) == 0)
583 		    strcat(buf,"\n   ");
584 		sprintf(buf, "%s %08lx", buf, *res_ptr);
585 	}
586 #endif
587 	strcat(buf, "\n");
588 	return strlen(buf);
589 }
590 
591