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