1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 ** PARISC 1.1 Dynamic DMA mapping support.
4 ** This implementation is for PA-RISC platforms that do not support
5 ** I/O TLBs (aka DMA address translation hardware).
6 ** See Documentation/DMA-API-HOWTO.txt for interface definitions.
7 **
8 ** (c) Copyright 1999,2000 Hewlett-Packard Company
9 ** (c) Copyright 2000 Grant Grundler
10 ** (c) Copyright 2000 Philipp Rumpf <prumpf@tux.org>
11 ** (c) Copyright 2000 John Marvin
12 **
13 ** "leveraged" from 2.3.47: arch/ia64/kernel/pci-dma.c.
14 ** (I assume it's from David Mosberger-Tang but there was no Copyright)
15 **
16 ** AFAIK, all PA7100LC and PA7300LC platforms can use this code.
17 **
18 ** - ggg
19 */
20
21 #include <linux/init.h>
22 #include <linux/gfp.h>
23 #include <linux/mm.h>
24 #include <linux/proc_fs.h>
25 #include <linux/seq_file.h>
26 #include <linux/string.h>
27 #include <linux/types.h>
28 #include <linux/dma-direct.h>
29 #include <linux/dma-noncoherent.h>
30
31 #include <asm/cacheflush.h>
32 #include <asm/dma.h> /* for DMA_CHUNK_SIZE */
33 #include <asm/io.h>
34 #include <asm/page.h> /* get_order */
35 #include <asm/pgalloc.h>
36 #include <linux/uaccess.h>
37 #include <asm/tlbflush.h> /* for purge_tlb_*() macros */
38
39 static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL;
40 static unsigned long pcxl_used_bytes __read_mostly = 0;
41 static unsigned long pcxl_used_pages __read_mostly = 0;
42
43 extern unsigned long pcxl_dma_start; /* Start of pcxl dma mapping area */
44 static DEFINE_SPINLOCK(pcxl_res_lock);
45 static char *pcxl_res_map;
46 static int pcxl_res_hint;
47 static int pcxl_res_size;
48
49 #ifdef DEBUG_PCXL_RESOURCE
50 #define DBG_RES(x...) printk(x)
51 #else
52 #define DBG_RES(x...)
53 #endif
54
55
56 /*
57 ** Dump a hex representation of the resource map.
58 */
59
60 #ifdef DUMP_RESMAP
61 static
dump_resmap(void)62 void dump_resmap(void)
63 {
64 u_long *res_ptr = (unsigned long *)pcxl_res_map;
65 u_long i = 0;
66
67 printk("res_map: ");
68 for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr)
69 printk("%08lx ", *res_ptr);
70
71 printk("\n");
72 }
73 #else
dump_resmap(void)74 static inline void dump_resmap(void) {;}
75 #endif
76
map_pte_uncached(pte_t * pte,unsigned long vaddr,unsigned long size,unsigned long * paddr_ptr)77 static inline int map_pte_uncached(pte_t * pte,
78 unsigned long vaddr,
79 unsigned long size, unsigned long *paddr_ptr)
80 {
81 unsigned long end;
82 unsigned long orig_vaddr = vaddr;
83
84 vaddr &= ~PMD_MASK;
85 end = vaddr + size;
86 if (end > PMD_SIZE)
87 end = PMD_SIZE;
88 do {
89 unsigned long flags;
90
91 if (!pte_none(*pte))
92 printk(KERN_ERR "map_pte_uncached: page already exists\n");
93 purge_tlb_start(flags);
94 set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
95 pdtlb_kernel(orig_vaddr);
96 purge_tlb_end(flags);
97 vaddr += PAGE_SIZE;
98 orig_vaddr += PAGE_SIZE;
99 (*paddr_ptr) += PAGE_SIZE;
100 pte++;
101 } while (vaddr < end);
102 return 0;
103 }
104
map_pmd_uncached(pmd_t * pmd,unsigned long vaddr,unsigned long size,unsigned long * paddr_ptr)105 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
106 unsigned long size, unsigned long *paddr_ptr)
107 {
108 unsigned long end;
109 unsigned long orig_vaddr = vaddr;
110
111 vaddr &= ~PGDIR_MASK;
112 end = vaddr + size;
113 if (end > PGDIR_SIZE)
114 end = PGDIR_SIZE;
115 do {
116 pte_t * pte = pte_alloc_kernel(pmd, vaddr);
117 if (!pte)
118 return -ENOMEM;
119 if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr))
120 return -ENOMEM;
121 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
122 orig_vaddr += PMD_SIZE;
123 pmd++;
124 } while (vaddr < end);
125 return 0;
126 }
127
map_uncached_pages(unsigned long vaddr,unsigned long size,unsigned long paddr)128 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,
129 unsigned long paddr)
130 {
131 pgd_t * dir;
132 unsigned long end = vaddr + size;
133
134 dir = pgd_offset_k(vaddr);
135 do {
136 pmd_t *pmd;
137
138 pmd = pmd_alloc(NULL, dir, vaddr);
139 if (!pmd)
140 return -ENOMEM;
141 if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr))
142 return -ENOMEM;
143 vaddr = vaddr + PGDIR_SIZE;
144 dir++;
145 } while (vaddr && (vaddr < end));
146 return 0;
147 }
148
unmap_uncached_pte(pmd_t * pmd,unsigned long vaddr,unsigned long size)149 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
150 unsigned long size)
151 {
152 pte_t * pte;
153 unsigned long end;
154 unsigned long orig_vaddr = vaddr;
155
156 if (pmd_none(*pmd))
157 return;
158 if (pmd_bad(*pmd)) {
159 pmd_ERROR(*pmd);
160 pmd_clear(pmd);
161 return;
162 }
163 pte = pte_offset_map(pmd, vaddr);
164 vaddr &= ~PMD_MASK;
165 end = vaddr + size;
166 if (end > PMD_SIZE)
167 end = PMD_SIZE;
168 do {
169 unsigned long flags;
170 pte_t page = *pte;
171
172 pte_clear(&init_mm, vaddr, pte);
173 purge_tlb_start(flags);
174 pdtlb_kernel(orig_vaddr);
175 purge_tlb_end(flags);
176 vaddr += PAGE_SIZE;
177 orig_vaddr += PAGE_SIZE;
178 pte++;
179 if (pte_none(page) || pte_present(page))
180 continue;
181 printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
182 } while (vaddr < end);
183 }
184
unmap_uncached_pmd(pgd_t * dir,unsigned long vaddr,unsigned long size)185 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr,
186 unsigned long size)
187 {
188 pmd_t * pmd;
189 unsigned long end;
190 unsigned long orig_vaddr = vaddr;
191
192 if (pgd_none(*dir))
193 return;
194 if (pgd_bad(*dir)) {
195 pgd_ERROR(*dir);
196 pgd_clear(dir);
197 return;
198 }
199 pmd = pmd_offset(dir, vaddr);
200 vaddr &= ~PGDIR_MASK;
201 end = vaddr + size;
202 if (end > PGDIR_SIZE)
203 end = PGDIR_SIZE;
204 do {
205 unmap_uncached_pte(pmd, orig_vaddr, end - vaddr);
206 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
207 orig_vaddr += PMD_SIZE;
208 pmd++;
209 } while (vaddr < end);
210 }
211
unmap_uncached_pages(unsigned long vaddr,unsigned long size)212 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size)
213 {
214 pgd_t * dir;
215 unsigned long end = vaddr + size;
216
217 dir = pgd_offset_k(vaddr);
218 do {
219 unmap_uncached_pmd(dir, vaddr, end - vaddr);
220 vaddr = vaddr + PGDIR_SIZE;
221 dir++;
222 } while (vaddr && (vaddr < end));
223 }
224
225 #define PCXL_SEARCH_LOOP(idx, mask, size) \
226 for(; res_ptr < res_end; ++res_ptr) \
227 { \
228 if(0 == ((*res_ptr) & mask)) { \
229 *res_ptr |= mask; \
230 idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \
231 pcxl_res_hint = idx + (size >> 3); \
232 goto resource_found; \
233 } \
234 }
235
236 #define PCXL_FIND_FREE_MAPPING(idx, mask, size) { \
237 u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \
238 u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \
239 PCXL_SEARCH_LOOP(idx, mask, size); \
240 res_ptr = (u##size *)&pcxl_res_map[0]; \
241 PCXL_SEARCH_LOOP(idx, mask, size); \
242 }
243
244 unsigned long
pcxl_alloc_range(size_t size)245 pcxl_alloc_range(size_t size)
246 {
247 int res_idx;
248 u_long mask, flags;
249 unsigned int pages_needed = size >> PAGE_SHIFT;
250
251 mask = (u_long) -1L;
252 mask >>= BITS_PER_LONG - pages_needed;
253
254 DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n",
255 size, pages_needed, mask);
256
257 spin_lock_irqsave(&pcxl_res_lock, flags);
258
259 if(pages_needed <= 8) {
260 PCXL_FIND_FREE_MAPPING(res_idx, mask, 8);
261 } else if(pages_needed <= 16) {
262 PCXL_FIND_FREE_MAPPING(res_idx, mask, 16);
263 } else if(pages_needed <= 32) {
264 PCXL_FIND_FREE_MAPPING(res_idx, mask, 32);
265 } else {
266 panic("%s: pcxl_alloc_range() Too many pages to map.\n",
267 __FILE__);
268 }
269
270 dump_resmap();
271 panic("%s: pcxl_alloc_range() out of dma mapping resources\n",
272 __FILE__);
273
274 resource_found:
275
276 DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n",
277 res_idx, mask, pcxl_res_hint);
278
279 pcxl_used_pages += pages_needed;
280 pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1);
281
282 spin_unlock_irqrestore(&pcxl_res_lock, flags);
283
284 dump_resmap();
285
286 /*
287 ** return the corresponding vaddr in the pcxl dma map
288 */
289 return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3)));
290 }
291
292 #define PCXL_FREE_MAPPINGS(idx, m, size) \
293 u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \
294 /* BUG_ON((*res_ptr & m) != m); */ \
295 *res_ptr &= ~m;
296
297 /*
298 ** clear bits in the pcxl resource map
299 */
300 static void
pcxl_free_range(unsigned long vaddr,size_t size)301 pcxl_free_range(unsigned long vaddr, size_t size)
302 {
303 u_long mask, flags;
304 unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3);
305 unsigned int pages_mapped = size >> PAGE_SHIFT;
306
307 mask = (u_long) -1L;
308 mask >>= BITS_PER_LONG - pages_mapped;
309
310 DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n",
311 res_idx, size, pages_mapped, mask);
312
313 spin_lock_irqsave(&pcxl_res_lock, flags);
314
315 if(pages_mapped <= 8) {
316 PCXL_FREE_MAPPINGS(res_idx, mask, 8);
317 } else if(pages_mapped <= 16) {
318 PCXL_FREE_MAPPINGS(res_idx, mask, 16);
319 } else if(pages_mapped <= 32) {
320 PCXL_FREE_MAPPINGS(res_idx, mask, 32);
321 } else {
322 panic("%s: pcxl_free_range() Too many pages to unmap.\n",
323 __FILE__);
324 }
325
326 pcxl_used_pages -= (pages_mapped ? pages_mapped : 1);
327 pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1);
328
329 spin_unlock_irqrestore(&pcxl_res_lock, flags);
330
331 dump_resmap();
332 }
333
proc_pcxl_dma_show(struct seq_file * m,void * v)334 static int proc_pcxl_dma_show(struct seq_file *m, void *v)
335 {
336 #if 0
337 u_long i = 0;
338 unsigned long *res_ptr = (u_long *)pcxl_res_map;
339 #endif
340 unsigned long total_pages = pcxl_res_size << 3; /* 8 bits per byte */
341
342 seq_printf(m, "\nDMA Mapping Area size : %d bytes (%ld pages)\n",
343 PCXL_DMA_MAP_SIZE, total_pages);
344
345 seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size);
346
347 seq_puts(m, " total: free: used: % used:\n");
348 seq_printf(m, "blocks %8d %8ld %8ld %8ld%%\n", pcxl_res_size,
349 pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes,
350 (pcxl_used_bytes * 100) / pcxl_res_size);
351
352 seq_printf(m, "pages %8ld %8ld %8ld %8ld%%\n", total_pages,
353 total_pages - pcxl_used_pages, pcxl_used_pages,
354 (pcxl_used_pages * 100 / total_pages));
355
356 #if 0
357 seq_puts(m, "\nResource bitmap:");
358
359 for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) {
360 if ((i & 7) == 0)
361 seq_puts(m,"\n ");
362 seq_printf(m, "%s %08lx", buf, *res_ptr);
363 }
364 #endif
365 seq_putc(m, '\n');
366 return 0;
367 }
368
369 static int __init
pcxl_dma_init(void)370 pcxl_dma_init(void)
371 {
372 if (pcxl_dma_start == 0)
373 return 0;
374
375 pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3);
376 pcxl_res_hint = 0;
377 pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL,
378 get_order(pcxl_res_size));
379 memset(pcxl_res_map, 0, pcxl_res_size);
380 proc_gsc_root = proc_mkdir("gsc", NULL);
381 if (!proc_gsc_root)
382 printk(KERN_WARNING
383 "pcxl_dma_init: Unable to create gsc /proc dir entry\n");
384 else {
385 struct proc_dir_entry* ent;
386 ent = proc_create_single("pcxl_dma", 0, proc_gsc_root,
387 proc_pcxl_dma_show);
388 if (!ent)
389 printk(KERN_WARNING
390 "pci-dma.c: Unable to create pcxl_dma /proc entry.\n");
391 }
392 return 0;
393 }
394
395 __initcall(pcxl_dma_init);
396
arch_dma_alloc(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t gfp,unsigned long attrs)397 void *arch_dma_alloc(struct device *dev, size_t size,
398 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
399 {
400 unsigned long vaddr;
401 unsigned long paddr;
402 int order;
403
404 if (boot_cpu_data.cpu_type != pcxl2 && boot_cpu_data.cpu_type != pcxl)
405 return NULL;
406
407 order = get_order(size);
408 size = 1 << (order + PAGE_SHIFT);
409 vaddr = pcxl_alloc_range(size);
410 paddr = __get_free_pages(gfp | __GFP_ZERO, order);
411 flush_kernel_dcache_range(paddr, size);
412 paddr = __pa(paddr);
413 map_uncached_pages(vaddr, size, paddr);
414 *dma_handle = (dma_addr_t) paddr;
415
416 #if 0
417 /* This probably isn't needed to support EISA cards.
418 ** ISA cards will certainly only support 24-bit DMA addressing.
419 ** Not clear if we can, want, or need to support ISA.
420 */
421 if (!dev || *dev->coherent_dma_mask < 0xffffffff)
422 gfp |= GFP_DMA;
423 #endif
424 return (void *)vaddr;
425 }
426
arch_dma_free(struct device * dev,size_t size,void * vaddr,dma_addr_t dma_handle,unsigned long attrs)427 void arch_dma_free(struct device *dev, size_t size, void *vaddr,
428 dma_addr_t dma_handle, unsigned long attrs)
429 {
430 int order = get_order(size);
431
432 WARN_ON_ONCE(boot_cpu_data.cpu_type != pcxl2 &&
433 boot_cpu_data.cpu_type != pcxl);
434
435 size = 1 << (order + PAGE_SHIFT);
436 unmap_uncached_pages((unsigned long)vaddr, size);
437 pcxl_free_range((unsigned long)vaddr, size);
438
439 free_pages((unsigned long)__va(dma_handle), order);
440 }
441
arch_sync_dma_for_device(phys_addr_t paddr,size_t size,enum dma_data_direction dir)442 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
443 enum dma_data_direction dir)
444 {
445 /*
446 * fdc: The data cache line is written back to memory, if and only if
447 * it is dirty, and then invalidated from the data cache.
448 */
449 flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size);
450 }
451
arch_sync_dma_for_cpu(phys_addr_t paddr,size_t size,enum dma_data_direction dir)452 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
453 enum dma_data_direction dir)
454 {
455 unsigned long addr = (unsigned long) phys_to_virt(paddr);
456
457 switch (dir) {
458 case DMA_TO_DEVICE:
459 case DMA_BIDIRECTIONAL:
460 flush_kernel_dcache_range(addr, size);
461 return;
462 case DMA_FROM_DEVICE:
463 purge_kernel_dcache_range_asm(addr, addr + size);
464 return;
465 default:
466 BUG();
467 }
468 }
469
arch_dma_cache_sync(struct device * dev,void * vaddr,size_t size,enum dma_data_direction direction)470 void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
471 enum dma_data_direction direction)
472 {
473 flush_kernel_dcache_range((unsigned long)vaddr, size);
474 }
475