1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/arch/m68k/sun3/sun3dvma.c
4 *
5 * Copyright (C) 2000 Sam Creasey
6 *
7 * Contains common routines for sun3/sun3x DVMA management.
8 */
9
10 #include <linux/bootmem.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/gfp.h>
15 #include <linux/mm.h>
16 #include <linux/list.h>
17
18 #include <asm/page.h>
19 #include <asm/pgtable.h>
20 #include <asm/dvma.h>
21
22 #undef DVMA_DEBUG
23
24 #ifdef CONFIG_SUN3X
25 extern void dvma_unmap_iommu(unsigned long baddr, int len);
26 #else
dvma_unmap_iommu(unsigned long a,int b)27 static inline void dvma_unmap_iommu(unsigned long a, int b)
28 {
29 }
30 #endif
31
32 #ifdef CONFIG_SUN3
33 extern void sun3_dvma_init(void);
34 #endif
35
36 static unsigned long *iommu_use;
37
38 #define dvma_index(baddr) ((baddr - DVMA_START) >> DVMA_PAGE_SHIFT)
39
40 #define dvma_entry_use(baddr) (iommu_use[dvma_index(baddr)])
41
42 struct hole {
43 unsigned long start;
44 unsigned long end;
45 unsigned long size;
46 struct list_head list;
47 };
48
49 static struct list_head hole_list;
50 static struct list_head hole_cache;
51 static struct hole initholes[64];
52
53 #ifdef DVMA_DEBUG
54
55 static unsigned long dvma_allocs;
56 static unsigned long dvma_frees;
57 static unsigned long long dvma_alloc_bytes;
58 static unsigned long long dvma_free_bytes;
59
print_use(void)60 static void print_use(void)
61 {
62
63 int i;
64 int j = 0;
65
66 pr_info("dvma entry usage:\n");
67
68 for(i = 0; i < IOMMU_TOTAL_ENTRIES; i++) {
69 if(!iommu_use[i])
70 continue;
71
72 j++;
73
74 pr_info("dvma entry: %08x len %08lx\n",
75 (i << DVMA_PAGE_SHIFT) + DVMA_START, iommu_use[i]);
76 }
77
78 pr_info("%d entries in use total\n", j);
79
80 pr_info("allocation/free calls: %lu/%lu\n", dvma_allocs, dvma_frees);
81 pr_info("allocation/free bytes: %Lx/%Lx\n", dvma_alloc_bytes,
82 dvma_free_bytes);
83 }
84
print_holes(struct list_head * holes)85 static void print_holes(struct list_head *holes)
86 {
87
88 struct list_head *cur;
89 struct hole *hole;
90
91 pr_info("listing dvma holes\n");
92 list_for_each(cur, holes) {
93 hole = list_entry(cur, struct hole, list);
94
95 if((hole->start == 0) && (hole->end == 0) && (hole->size == 0))
96 continue;
97
98 pr_info("hole: start %08lx end %08lx size %08lx\n",
99 hole->start, hole->end, hole->size);
100 }
101
102 pr_info("end of hole listing...\n");
103 }
104 #endif /* DVMA_DEBUG */
105
refill(void)106 static inline int refill(void)
107 {
108
109 struct hole *hole;
110 struct hole *prev = NULL;
111 struct list_head *cur;
112 int ret = 0;
113
114 list_for_each(cur, &hole_list) {
115 hole = list_entry(cur, struct hole, list);
116
117 if(!prev) {
118 prev = hole;
119 continue;
120 }
121
122 if(hole->end == prev->start) {
123 hole->size += prev->size;
124 hole->end = prev->end;
125 list_move(&(prev->list), &hole_cache);
126 ret++;
127 }
128
129 }
130
131 return ret;
132 }
133
rmcache(void)134 static inline struct hole *rmcache(void)
135 {
136 struct hole *ret;
137
138 if(list_empty(&hole_cache)) {
139 if(!refill()) {
140 pr_crit("out of dvma hole cache!\n");
141 BUG();
142 }
143 }
144
145 ret = list_entry(hole_cache.next, struct hole, list);
146 list_del(&(ret->list));
147
148 return ret;
149
150 }
151
get_baddr(int len,unsigned long align)152 static inline unsigned long get_baddr(int len, unsigned long align)
153 {
154
155 struct list_head *cur;
156 struct hole *hole;
157
158 if(list_empty(&hole_list)) {
159 #ifdef DVMA_DEBUG
160 pr_crit("out of dvma holes! (printing hole cache)\n");
161 print_holes(&hole_cache);
162 print_use();
163 #endif
164 BUG();
165 }
166
167 list_for_each(cur, &hole_list) {
168 unsigned long newlen;
169
170 hole = list_entry(cur, struct hole, list);
171
172 if(align > DVMA_PAGE_SIZE)
173 newlen = len + ((hole->end - len) & (align-1));
174 else
175 newlen = len;
176
177 if(hole->size > newlen) {
178 hole->end -= newlen;
179 hole->size -= newlen;
180 dvma_entry_use(hole->end) = newlen;
181 #ifdef DVMA_DEBUG
182 dvma_allocs++;
183 dvma_alloc_bytes += newlen;
184 #endif
185 return hole->end;
186 } else if(hole->size == newlen) {
187 list_move(&(hole->list), &hole_cache);
188 dvma_entry_use(hole->start) = newlen;
189 #ifdef DVMA_DEBUG
190 dvma_allocs++;
191 dvma_alloc_bytes += newlen;
192 #endif
193 return hole->start;
194 }
195
196 }
197
198 pr_crit("unable to find dvma hole!\n");
199 BUG();
200 return 0;
201 }
202
free_baddr(unsigned long baddr)203 static inline int free_baddr(unsigned long baddr)
204 {
205
206 unsigned long len;
207 struct hole *hole;
208 struct list_head *cur;
209 unsigned long orig_baddr;
210
211 orig_baddr = baddr;
212 len = dvma_entry_use(baddr);
213 dvma_entry_use(baddr) = 0;
214 baddr &= DVMA_PAGE_MASK;
215 dvma_unmap_iommu(baddr, len);
216
217 #ifdef DVMA_DEBUG
218 dvma_frees++;
219 dvma_free_bytes += len;
220 #endif
221
222 list_for_each(cur, &hole_list) {
223 hole = list_entry(cur, struct hole, list);
224
225 if(hole->end == baddr) {
226 hole->end += len;
227 hole->size += len;
228 return 0;
229 } else if(hole->start == (baddr + len)) {
230 hole->start = baddr;
231 hole->size += len;
232 return 0;
233 }
234
235 }
236
237 hole = rmcache();
238
239 hole->start = baddr;
240 hole->end = baddr + len;
241 hole->size = len;
242
243 // list_add_tail(&(hole->list), cur);
244 list_add(&(hole->list), cur);
245
246 return 0;
247
248 }
249
dvma_init(void)250 void __init dvma_init(void)
251 {
252
253 struct hole *hole;
254 int i;
255
256 INIT_LIST_HEAD(&hole_list);
257 INIT_LIST_HEAD(&hole_cache);
258
259 /* prepare the hole cache */
260 for(i = 0; i < 64; i++)
261 list_add(&(initholes[i].list), &hole_cache);
262
263 hole = rmcache();
264 hole->start = DVMA_START;
265 hole->end = DVMA_END;
266 hole->size = DVMA_SIZE;
267
268 list_add(&(hole->list), &hole_list);
269
270 iommu_use = alloc_bootmem(IOMMU_TOTAL_ENTRIES * sizeof(unsigned long));
271
272 dvma_unmap_iommu(DVMA_START, DVMA_SIZE);
273
274 #ifdef CONFIG_SUN3
275 sun3_dvma_init();
276 #endif
277
278 }
279
dvma_map_align(unsigned long kaddr,int len,int align)280 unsigned long dvma_map_align(unsigned long kaddr, int len, int align)
281 {
282
283 unsigned long baddr;
284 unsigned long off;
285
286 if(!len)
287 len = 0x800;
288
289 if(!kaddr || !len) {
290 // pr_err("error: kaddr %lx len %x\n", kaddr, len);
291 // *(int *)4 = 0;
292 return 0;
293 }
294
295 pr_debug("dvma_map request %08x bytes from %08lx\n", len, kaddr);
296 off = kaddr & ~DVMA_PAGE_MASK;
297 kaddr &= PAGE_MASK;
298 len += off;
299 len = ((len + (DVMA_PAGE_SIZE-1)) & DVMA_PAGE_MASK);
300
301 if(align == 0)
302 align = DVMA_PAGE_SIZE;
303 else
304 align = ((align + (DVMA_PAGE_SIZE-1)) & DVMA_PAGE_MASK);
305
306 baddr = get_baddr(len, align);
307 // pr_info("using baddr %lx\n", baddr);
308
309 if(!dvma_map_iommu(kaddr, baddr, len))
310 return (baddr + off);
311
312 pr_crit("dvma_map failed kaddr %lx baddr %lx len %x\n", kaddr, baddr,
313 len);
314 BUG();
315 return 0;
316 }
317 EXPORT_SYMBOL(dvma_map_align);
318
dvma_unmap(void * baddr)319 void dvma_unmap(void *baddr)
320 {
321 unsigned long addr;
322
323 addr = (unsigned long)baddr;
324 /* check if this is a vme mapping */
325 if(!(addr & 0x00f00000))
326 addr |= 0xf00000;
327
328 free_baddr(addr);
329
330 return;
331
332 }
333 EXPORT_SYMBOL(dvma_unmap);
334
dvma_malloc_align(unsigned long len,unsigned long align)335 void *dvma_malloc_align(unsigned long len, unsigned long align)
336 {
337 unsigned long kaddr;
338 unsigned long baddr;
339 unsigned long vaddr;
340
341 if(!len)
342 return NULL;
343
344 pr_debug("dvma_malloc request %lx bytes\n", len);
345 len = ((len + (DVMA_PAGE_SIZE-1)) & DVMA_PAGE_MASK);
346
347 if((kaddr = __get_free_pages(GFP_ATOMIC, get_order(len))) == 0)
348 return NULL;
349
350 if((baddr = (unsigned long)dvma_map_align(kaddr, len, align)) == 0) {
351 free_pages(kaddr, get_order(len));
352 return NULL;
353 }
354
355 vaddr = dvma_btov(baddr);
356
357 if(dvma_map_cpu(kaddr, vaddr, len) < 0) {
358 dvma_unmap((void *)baddr);
359 free_pages(kaddr, get_order(len));
360 return NULL;
361 }
362
363 pr_debug("mapped %08lx bytes %08lx kern -> %08lx bus\n", len, kaddr,
364 baddr);
365
366 return (void *)vaddr;
367
368 }
369 EXPORT_SYMBOL(dvma_malloc_align);
370
dvma_free(void * vaddr)371 void dvma_free(void *vaddr)
372 {
373
374 return;
375
376 }
377 EXPORT_SYMBOL(dvma_free);
378