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/core-api/dma-api-howto.rst 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-map-ops.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 <linux/uaccess.h>
36 #include <asm/tlbflush.h> /* for purge_tlb_*() macros */
37
38 static struct proc_dir_entry * proc_gsc_root __read_mostly = NULL;
39 static unsigned long pcxl_used_bytes __read_mostly;
40 static unsigned long pcxl_used_pages __read_mostly;
41
42 unsigned long pcxl_dma_start __ro_after_init; /* pcxl dma mapping area start */
43 static DEFINE_SPINLOCK(pcxl_res_lock);
44 static char *pcxl_res_map;
45 static int pcxl_res_hint;
46 static int pcxl_res_size;
47
48 #ifdef DEBUG_PCXL_RESOURCE
49 #define DBG_RES(x...) printk(x)
50 #else
51 #define DBG_RES(x...)
52 #endif
53
54
55 /*
56 ** Dump a hex representation of the resource map.
57 */
58
59 #ifdef DUMP_RESMAP
60 static
61 void dump_resmap(void)
62 {
63 u_long *res_ptr = (unsigned long *)pcxl_res_map;
64 u_long i = 0;
65
66 printk("res_map: ");
67 for(; i < (pcxl_res_size / sizeof(unsigned long)); ++i, ++res_ptr)
68 printk("%08lx ", *res_ptr);
69
70 printk("\n");
71 }
72 #else
73 static inline void dump_resmap(void) {;}
74 #endif
75
76 static inline int map_pte_uncached(pte_t * pte,
77 unsigned long vaddr,
78 unsigned long size, unsigned long *paddr_ptr)
79 {
80 unsigned long end;
81 unsigned long orig_vaddr = vaddr;
82
83 vaddr &= ~PMD_MASK;
84 end = vaddr + size;
85 if (end > PMD_SIZE)
86 end = PMD_SIZE;
87 do {
88 unsigned long flags;
89
90 if (!pte_none(*pte))
91 printk(KERN_ERR "map_pte_uncached: page already exists\n");
92 purge_tlb_start(flags);
93 set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC));
94 pdtlb(SR_KERNEL, orig_vaddr);
95 purge_tlb_end(flags);
96 vaddr += PAGE_SIZE;
97 orig_vaddr += PAGE_SIZE;
98 (*paddr_ptr) += PAGE_SIZE;
99 pte++;
100 } while (vaddr < end);
101 return 0;
102 }
103
104 static inline int map_pmd_uncached(pmd_t * pmd, unsigned long vaddr,
105 unsigned long size, unsigned long *paddr_ptr)
106 {
107 unsigned long end;
108 unsigned long orig_vaddr = vaddr;
109
110 vaddr &= ~PGDIR_MASK;
111 end = vaddr + size;
112 if (end > PGDIR_SIZE)
113 end = PGDIR_SIZE;
114 do {
115 pte_t * pte = pte_alloc_kernel(pmd, vaddr);
116 if (!pte)
117 return -ENOMEM;
118 if (map_pte_uncached(pte, orig_vaddr, end - vaddr, paddr_ptr))
119 return -ENOMEM;
120 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
121 orig_vaddr += PMD_SIZE;
122 pmd++;
123 } while (vaddr < end);
124 return 0;
125 }
126
127 static inline int map_uncached_pages(unsigned long vaddr, unsigned long size,
128 unsigned long paddr)
129 {
130 pgd_t * dir;
131 unsigned long end = vaddr + size;
132
133 dir = pgd_offset_k(vaddr);
134 do {
135 p4d_t *p4d;
136 pud_t *pud;
137 pmd_t *pmd;
138
139 p4d = p4d_offset(dir, vaddr);
140 pud = pud_offset(p4d, vaddr);
141 pmd = pmd_alloc(NULL, pud, vaddr);
142
143 if (!pmd)
144 return -ENOMEM;
145 if (map_pmd_uncached(pmd, vaddr, end - vaddr, &paddr))
146 return -ENOMEM;
147 vaddr = vaddr + PGDIR_SIZE;
148 dir++;
149 } while (vaddr && (vaddr < end));
150 return 0;
151 }
152
153 static inline void unmap_uncached_pte(pmd_t * pmd, unsigned long vaddr,
154 unsigned long size)
155 {
156 pte_t * pte;
157 unsigned long end;
158 unsigned long orig_vaddr = vaddr;
159
160 if (pmd_none(*pmd))
161 return;
162 if (pmd_bad(*pmd)) {
163 pmd_ERROR(*pmd);
164 pmd_clear(pmd);
165 return;
166 }
167 pte = pte_offset_kernel(pmd, vaddr);
168 vaddr &= ~PMD_MASK;
169 end = vaddr + size;
170 if (end > PMD_SIZE)
171 end = PMD_SIZE;
172 do {
173 unsigned long flags;
174 pte_t page = *pte;
175
176 pte_clear(&init_mm, vaddr, pte);
177 purge_tlb_start(flags);
178 pdtlb(SR_KERNEL, orig_vaddr);
179 purge_tlb_end(flags);
180 vaddr += PAGE_SIZE;
181 orig_vaddr += PAGE_SIZE;
182 pte++;
183 if (pte_none(page) || pte_present(page))
184 continue;
185 printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
186 } while (vaddr < end);
187 }
188
189 static inline void unmap_uncached_pmd(pgd_t * dir, unsigned long vaddr,
190 unsigned long size)
191 {
192 pmd_t * pmd;
193 unsigned long end;
194 unsigned long orig_vaddr = vaddr;
195
196 if (pgd_none(*dir))
197 return;
198 if (pgd_bad(*dir)) {
199 pgd_ERROR(*dir);
200 pgd_clear(dir);
201 return;
202 }
203 pmd = pmd_offset(pud_offset(p4d_offset(dir, vaddr), vaddr), vaddr);
204 vaddr &= ~PGDIR_MASK;
205 end = vaddr + size;
206 if (end > PGDIR_SIZE)
207 end = PGDIR_SIZE;
208 do {
209 unmap_uncached_pte(pmd, orig_vaddr, end - vaddr);
210 vaddr = (vaddr + PMD_SIZE) & PMD_MASK;
211 orig_vaddr += PMD_SIZE;
212 pmd++;
213 } while (vaddr < end);
214 }
215
216 static void unmap_uncached_pages(unsigned long vaddr, unsigned long size)
217 {
218 pgd_t * dir;
219 unsigned long end = vaddr + size;
220
221 dir = pgd_offset_k(vaddr);
222 do {
223 unmap_uncached_pmd(dir, vaddr, end - vaddr);
224 vaddr = vaddr + PGDIR_SIZE;
225 dir++;
226 } while (vaddr && (vaddr < end));
227 }
228
229 #define PCXL_SEARCH_LOOP(idx, mask, size) \
230 for(; res_ptr < res_end; ++res_ptr) \
231 { \
232 if(0 == ((*res_ptr) & mask)) { \
233 *res_ptr |= mask; \
234 idx = (int)((u_long)res_ptr - (u_long)pcxl_res_map); \
235 pcxl_res_hint = idx + (size >> 3); \
236 goto resource_found; \
237 } \
238 }
239
240 #define PCXL_FIND_FREE_MAPPING(idx, mask, size) { \
241 u##size *res_ptr = (u##size *)&(pcxl_res_map[pcxl_res_hint & ~((size >> 3) - 1)]); \
242 u##size *res_end = (u##size *)&pcxl_res_map[pcxl_res_size]; \
243 PCXL_SEARCH_LOOP(idx, mask, size); \
244 res_ptr = (u##size *)&pcxl_res_map[0]; \
245 PCXL_SEARCH_LOOP(idx, mask, size); \
246 }
247
248 static unsigned long
249 pcxl_alloc_range(size_t size)
250 {
251 int res_idx;
252 u_long mask, flags;
253 unsigned int pages_needed = size >> PAGE_SHIFT;
254
255 mask = (u_long) -1L;
256 mask >>= BITS_PER_LONG - pages_needed;
257
258 DBG_RES("pcxl_alloc_range() size: %d pages_needed %d pages_mask 0x%08lx\n",
259 size, pages_needed, mask);
260
261 spin_lock_irqsave(&pcxl_res_lock, flags);
262
263 if(pages_needed <= 8) {
264 PCXL_FIND_FREE_MAPPING(res_idx, mask, 8);
265 } else if(pages_needed <= 16) {
266 PCXL_FIND_FREE_MAPPING(res_idx, mask, 16);
267 } else if(pages_needed <= 32) {
268 PCXL_FIND_FREE_MAPPING(res_idx, mask, 32);
269 } else {
270 panic("%s: pcxl_alloc_range() Too many pages to map.\n",
271 __FILE__);
272 }
273
274 dump_resmap();
275 panic("%s: pcxl_alloc_range() out of dma mapping resources\n",
276 __FILE__);
277
278 resource_found:
279
280 DBG_RES("pcxl_alloc_range() res_idx %d mask 0x%08lx res_hint: %d\n",
281 res_idx, mask, pcxl_res_hint);
282
283 pcxl_used_pages += pages_needed;
284 pcxl_used_bytes += ((pages_needed >> 3) ? (pages_needed >> 3) : 1);
285
286 spin_unlock_irqrestore(&pcxl_res_lock, flags);
287
288 dump_resmap();
289
290 /*
291 ** return the corresponding vaddr in the pcxl dma map
292 */
293 return (pcxl_dma_start + (res_idx << (PAGE_SHIFT + 3)));
294 }
295
296 #define PCXL_FREE_MAPPINGS(idx, m, size) \
297 u##size *res_ptr = (u##size *)&(pcxl_res_map[(idx) + (((size >> 3) - 1) & (~((size >> 3) - 1)))]); \
298 /* BUG_ON((*res_ptr & m) != m); */ \
299 *res_ptr &= ~m;
300
301 /*
302 ** clear bits in the pcxl resource map
303 */
304 static void
305 pcxl_free_range(unsigned long vaddr, size_t size)
306 {
307 u_long mask, flags;
308 unsigned int res_idx = (vaddr - pcxl_dma_start) >> (PAGE_SHIFT + 3);
309 unsigned int pages_mapped = size >> PAGE_SHIFT;
310
311 mask = (u_long) -1L;
312 mask >>= BITS_PER_LONG - pages_mapped;
313
314 DBG_RES("pcxl_free_range() res_idx: %d size: %d pages_mapped %d mask 0x%08lx\n",
315 res_idx, size, pages_mapped, mask);
316
317 spin_lock_irqsave(&pcxl_res_lock, flags);
318
319 if(pages_mapped <= 8) {
320 PCXL_FREE_MAPPINGS(res_idx, mask, 8);
321 } else if(pages_mapped <= 16) {
322 PCXL_FREE_MAPPINGS(res_idx, mask, 16);
323 } else if(pages_mapped <= 32) {
324 PCXL_FREE_MAPPINGS(res_idx, mask, 32);
325 } else {
326 panic("%s: pcxl_free_range() Too many pages to unmap.\n",
327 __FILE__);
328 }
329
330 pcxl_used_pages -= (pages_mapped ? pages_mapped : 1);
331 pcxl_used_bytes -= ((pages_mapped >> 3) ? (pages_mapped >> 3) : 1);
332
333 spin_unlock_irqrestore(&pcxl_res_lock, flags);
334
335 dump_resmap();
336 }
337
338 static int __maybe_unused proc_pcxl_dma_show(struct seq_file *m, void *v)
339 {
340 #if 0
341 u_long i = 0;
342 unsigned long *res_ptr = (u_long *)pcxl_res_map;
343 #endif
344 unsigned long total_pages = pcxl_res_size << 3; /* 8 bits per byte */
345
346 seq_printf(m, "\nDMA Mapping Area size : %d bytes (%ld pages)\n",
347 PCXL_DMA_MAP_SIZE, total_pages);
348
349 seq_printf(m, "Resource bitmap : %d bytes\n", pcxl_res_size);
350
351 seq_puts(m, " total: free: used: % used:\n");
352 seq_printf(m, "blocks %8d %8ld %8ld %8ld%%\n", pcxl_res_size,
353 pcxl_res_size - pcxl_used_bytes, pcxl_used_bytes,
354 (pcxl_used_bytes * 100) / pcxl_res_size);
355
356 seq_printf(m, "pages %8ld %8ld %8ld %8ld%%\n", total_pages,
357 total_pages - pcxl_used_pages, pcxl_used_pages,
358 (pcxl_used_pages * 100 / total_pages));
359
360 #if 0
361 seq_puts(m, "\nResource bitmap:");
362
363 for(; i < (pcxl_res_size / sizeof(u_long)); ++i, ++res_ptr) {
364 if ((i & 7) == 0)
365 seq_puts(m,"\n ");
366 seq_printf(m, "%s %08lx", buf, *res_ptr);
367 }
368 #endif
369 seq_putc(m, '\n');
370 return 0;
371 }
372
373 static int __init
374 pcxl_dma_init(void)
375 {
376 if (pcxl_dma_start == 0)
377 return 0;
378
379 pcxl_res_size = PCXL_DMA_MAP_SIZE >> (PAGE_SHIFT + 3);
380 pcxl_res_hint = 0;
381 pcxl_res_map = (char *)__get_free_pages(GFP_KERNEL,
382 get_order(pcxl_res_size));
383 memset(pcxl_res_map, 0, pcxl_res_size);
384 proc_gsc_root = proc_mkdir("bus/gsc", NULL);
385 if (!proc_gsc_root)
386 printk(KERN_WARNING
387 "pcxl_dma_init: Unable to create gsc /proc dir entry\n");
388 else {
389 struct proc_dir_entry* ent;
390 ent = proc_create_single("pcxl_dma", 0, proc_gsc_root,
391 proc_pcxl_dma_show);
392 if (!ent)
393 printk(KERN_WARNING
394 "pci-dma.c: Unable to create pcxl_dma /proc entry.\n");
395 }
396 return 0;
397 }
398
399 __initcall(pcxl_dma_init);
400
401 void *arch_dma_alloc(struct device *dev, size_t size,
402 dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
403 {
404 unsigned long vaddr;
405 unsigned long paddr;
406 int order;
407
408 if (boot_cpu_data.cpu_type != pcxl2 && boot_cpu_data.cpu_type != pcxl)
409 return NULL;
410
411 order = get_order(size);
412 size = 1 << (order + PAGE_SHIFT);
413 vaddr = pcxl_alloc_range(size);
414 paddr = __get_free_pages(gfp | __GFP_ZERO, order);
415 flush_kernel_dcache_range(paddr, size);
416 paddr = __pa(paddr);
417 map_uncached_pages(vaddr, size, paddr);
418 *dma_handle = (dma_addr_t) paddr;
419
420 return (void *)vaddr;
421 }
422
423 void arch_dma_free(struct device *dev, size_t size, void *vaddr,
424 dma_addr_t dma_handle, unsigned long attrs)
425 {
426 int order = get_order(size);
427
428 WARN_ON_ONCE(boot_cpu_data.cpu_type != pcxl2 &&
429 boot_cpu_data.cpu_type != pcxl);
430
431 size = 1 << (order + PAGE_SHIFT);
432 unmap_uncached_pages((unsigned long)vaddr, size);
433 pcxl_free_range((unsigned long)vaddr, size);
434
435 free_pages((unsigned long)__va(dma_handle), order);
436 }
437
438 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
439 enum dma_data_direction dir)
440 {
441 /*
442 * fdc: The data cache line is written back to memory, if and only if
443 * it is dirty, and then invalidated from the data cache.
444 */
445 flush_kernel_dcache_range((unsigned long)phys_to_virt(paddr), size);
446 }
447
448 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
449 enum dma_data_direction dir)
450 {
451 unsigned long addr = (unsigned long) phys_to_virt(paddr);
452
453 switch (dir) {
454 case DMA_TO_DEVICE:
455 case DMA_BIDIRECTIONAL:
456 flush_kernel_dcache_range(addr, size);
457 return;
458 case DMA_FROM_DEVICE:
459 purge_kernel_dcache_range_asm(addr, addr + size);
460 return;
461 default:
462 BUG();
463 }
464 }
465
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