1 /*
2  * Device driver for the SYMBIOS/LSILOGIC 53C8XX and 53C1010 family
3  * of PCI-SCSI IO processors.
4  *
5  * Copyright (C) 1999-2001  Gerard Roudier <groudier@free.fr>
6  *
7  * This driver is derived from the Linux sym53c8xx driver.
8  * Copyright (C) 1998-2000  Gerard Roudier
9  *
10  * The sym53c8xx driver is derived from the ncr53c8xx driver that had been
11  * a port of the FreeBSD ncr driver to Linux-1.2.13.
12  *
13  * The original ncr driver has been written for 386bsd and FreeBSD by
14  *         Wolfgang Stanglmeier        <wolf@cologne.de>
15  *         Stefan Esser                <se@mi.Uni-Koeln.de>
16  * Copyright (C) 1994  Wolfgang Stanglmeier
17  *
18  * Other major contributions:
19  *
20  * NVRAM detection and reading.
21  * Copyright (C) 1997 Richard Waltham <dormouse@farsrobt.demon.co.uk>
22  *
23  *-----------------------------------------------------------------------------
24  *
25  * This program is free software; you can redistribute it and/or modify
26  * it under the terms of the GNU General Public License as published by
27  * the Free Software Foundation; either version 2 of the License, or
28  * (at your option) any later version.
29  *
30  * This program is distributed in the hope that it will be useful,
31  * but WITHOUT ANY WARRANTY; without even the implied warranty of
32  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
33  * GNU General Public License for more details.
34  *
35  * You should have received a copy of the GNU General Public License
36  * along with this program; if not, write to the Free Software
37  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
38  */
39 
40 #include "sym_glue.h"
41 
42 /*
43  *  Simple power of two buddy-like generic allocator.
44  *  Provides naturally aligned memory chunks.
45  *
46  *  This simple code is not intended to be fast, but to
47  *  provide power of 2 aligned memory allocations.
48  *  Since the SCRIPTS processor only supplies 8 bit arithmetic,
49  *  this allocator allows simple and fast address calculations
50  *  from the SCRIPTS code. In addition, cache line alignment
51  *  is guaranteed for power of 2 cache line size.
52  *
53  *  This allocator has been developed for the Linux sym53c8xx
54  *  driver, since this O/S does not provide naturally aligned
55  *  allocations.
56  *  It has the advantage of allowing the driver to use private
57  *  pages of memory that will be useful if we ever need to deal
58  *  with IO MMUs for PCI.
59  */
60 static void *___sym_malloc(m_pool_p mp, int size)
61 {
62 	int i = 0;
63 	int s = (1 << SYM_MEM_SHIFT);
64 	int j;
65 	void *a;
66 	m_link_p h = mp->h;
67 
68 	if (size > SYM_MEM_CLUSTER_SIZE)
69 		return NULL;
70 
71 	while (size > s) {
72 		s <<= 1;
73 		++i;
74 	}
75 
76 	j = i;
77 	while (!h[j].next) {
78 		if (s == SYM_MEM_CLUSTER_SIZE) {
79 			h[j].next = (m_link_p) M_GET_MEM_CLUSTER();
80 			if (h[j].next)
81 				h[j].next->next = NULL;
82 			break;
83 		}
84 		++j;
85 		s <<= 1;
86 	}
87 	a = h[j].next;
88 	if (a) {
89 		h[j].next = h[j].next->next;
90 		while (j > i) {
91 			j -= 1;
92 			s >>= 1;
93 			h[j].next = (m_link_p) (a+s);
94 			h[j].next->next = NULL;
95 		}
96 	}
97 #ifdef DEBUG
98 	printf("___sym_malloc(%d) = %p\n", size, (void *) a);
99 #endif
100 	return a;
101 }
102 
103 /*
104  *  Counter-part of the generic allocator.
105  */
106 static void ___sym_mfree(m_pool_p mp, void *ptr, int size)
107 {
108 	int i = 0;
109 	int s = (1 << SYM_MEM_SHIFT);
110 	m_link_p q;
111 	unsigned long a, b;
112 	m_link_p h = mp->h;
113 
114 #ifdef DEBUG
115 	printf("___sym_mfree(%p, %d)\n", ptr, size);
116 #endif
117 
118 	if (size > SYM_MEM_CLUSTER_SIZE)
119 		return;
120 
121 	while (size > s) {
122 		s <<= 1;
123 		++i;
124 	}
125 
126 	a = (unsigned long)ptr;
127 
128 	while (1) {
129 		if (s == SYM_MEM_CLUSTER_SIZE) {
130 #ifdef SYM_MEM_FREE_UNUSED
131 			M_FREE_MEM_CLUSTER((void *)a);
132 #else
133 			((m_link_p) a)->next = h[i].next;
134 			h[i].next = (m_link_p) a;
135 #endif
136 			break;
137 		}
138 		b = a ^ s;
139 		q = &h[i];
140 		while (q->next && q->next != (m_link_p) b) {
141 			q = q->next;
142 		}
143 		if (!q->next) {
144 			((m_link_p) a)->next = h[i].next;
145 			h[i].next = (m_link_p) a;
146 			break;
147 		}
148 		q->next = q->next->next;
149 		a = a & b;
150 		s <<= 1;
151 		++i;
152 	}
153 }
154 
155 /*
156  *  Verbose and zeroing allocator that wrapps to the generic allocator.
157  */
158 static void *__sym_calloc2(m_pool_p mp, int size, char *name, int uflags)
159 {
160 	void *p;
161 
162 	p = ___sym_malloc(mp, size);
163 
164 	if (DEBUG_FLAGS & DEBUG_ALLOC) {
165 		printf ("new %-10s[%4d] @%p.\n", name, size, p);
166 	}
167 
168 	if (p)
169 		memset(p, 0, size);
170 	else if (uflags & SYM_MEM_WARN)
171 		printf ("__sym_calloc2: failed to allocate %s[%d]\n", name, size);
172 	return p;
173 }
174 #define __sym_calloc(mp, s, n)	__sym_calloc2(mp, s, n, SYM_MEM_WARN)
175 
176 /*
177  *  Its counter-part.
178  */
179 static void __sym_mfree(m_pool_p mp, void *ptr, int size, char *name)
180 {
181 	if (DEBUG_FLAGS & DEBUG_ALLOC)
182 		printf ("freeing %-10s[%4d] @%p.\n", name, size, ptr);
183 
184 	___sym_mfree(mp, ptr, size);
185 }
186 
187 /*
188  *  Default memory pool we donnot need to involve in DMA.
189  *
190  *  With DMA abstraction, we use functions (methods), to
191  *  distinguish between non DMAable memory and DMAable memory.
192  */
193 static void *___mp0_get_mem_cluster(m_pool_p mp)
194 {
195 	void *m = sym_get_mem_cluster();
196 	if (m)
197 		++mp->nump;
198 	return m;
199 }
200 
201 #ifdef	SYM_MEM_FREE_UNUSED
202 static void ___mp0_free_mem_cluster(m_pool_p mp, void *m)
203 {
204 	sym_free_mem_cluster(m);
205 	--mp->nump;
206 }
207 #else
208 #define ___mp0_free_mem_cluster NULL
209 #endif
210 
211 static struct sym_m_pool mp0 = {
212 	NULL,
213 	___mp0_get_mem_cluster,
214 	___mp0_free_mem_cluster
215 };
216 
217 /*
218  *  Methods that maintains DMAable pools according to user allocations.
219  *  New pools are created on the fly when a new pool id is provided.
220  *  They are deleted on the fly when they get emptied.
221  */
222 /* Get a memory cluster that matches the DMA constraints of a given pool */
223 static void * ___get_dma_mem_cluster(m_pool_p mp)
224 {
225 	m_vtob_p vbp;
226 	void *vaddr;
227 
228 	vbp = __sym_calloc(&mp0, sizeof(*vbp), "VTOB");
229 	if (!vbp)
230 		goto out_err;
231 
232 	vaddr = sym_m_get_dma_mem_cluster(mp, vbp);
233 	if (vaddr) {
234 		int hc = VTOB_HASH_CODE(vaddr);
235 		vbp->next = mp->vtob[hc];
236 		mp->vtob[hc] = vbp;
237 		++mp->nump;
238 	}
239 	return vaddr;
240 out_err:
241 	return NULL;
242 }
243 
244 #ifdef	SYM_MEM_FREE_UNUSED
245 /* Free a memory cluster and associated resources for DMA */
246 static void ___free_dma_mem_cluster(m_pool_p mp, void *m)
247 {
248 	m_vtob_p *vbpp, vbp;
249 	int hc = VTOB_HASH_CODE(m);
250 
251 	vbpp = &mp->vtob[hc];
252 	while (*vbpp && (*vbpp)->vaddr != m)
253 		vbpp = &(*vbpp)->next;
254 	if (*vbpp) {
255 		vbp = *vbpp;
256 		*vbpp = (*vbpp)->next;
257 		sym_m_free_dma_mem_cluster(mp, vbp);
258 		__sym_mfree(&mp0, vbp, sizeof(*vbp), "VTOB");
259 		--mp->nump;
260 	}
261 }
262 #endif
263 
264 /* Fetch the memory pool for a given pool id (i.e. DMA constraints) */
265 static inline m_pool_p ___get_dma_pool(m_pool_ident_t dev_dmat)
266 {
267 	m_pool_p mp;
268 	for (mp = mp0.next;
269 		mp && !sym_m_pool_match(mp->dev_dmat, dev_dmat);
270 			mp = mp->next);
271 	return mp;
272 }
273 
274 /* Create a new memory DMAable pool (when fetch failed) */
275 static m_pool_p ___cre_dma_pool(m_pool_ident_t dev_dmat)
276 {
277 	m_pool_p mp = __sym_calloc(&mp0, sizeof(*mp), "MPOOL");
278 	if (mp) {
279 		mp->dev_dmat = dev_dmat;
280 		mp->get_mem_cluster = ___get_dma_mem_cluster;
281 #ifdef	SYM_MEM_FREE_UNUSED
282 		mp->free_mem_cluster = ___free_dma_mem_cluster;
283 #endif
284 		mp->next = mp0.next;
285 		mp0.next = mp;
286 		return mp;
287 	}
288 	return NULL;
289 }
290 
291 #ifdef	SYM_MEM_FREE_UNUSED
292 /* Destroy a DMAable memory pool (when got emptied) */
293 static void ___del_dma_pool(m_pool_p p)
294 {
295 	m_pool_p *pp = &mp0.next;
296 
297 	while (*pp && *pp != p)
298 		pp = &(*pp)->next;
299 	if (*pp) {
300 		*pp = (*pp)->next;
301 		__sym_mfree(&mp0, p, sizeof(*p), "MPOOL");
302 	}
303 }
304 #endif
305 
306 /* This lock protects only the memory allocation/free.  */
307 static DEFINE_SPINLOCK(sym53c8xx_lock);
308 
309 /*
310  *  Actual allocator for DMAable memory.
311  */
312 void *__sym_calloc_dma(m_pool_ident_t dev_dmat, int size, char *name)
313 {
314 	unsigned long flags;
315 	m_pool_p mp;
316 	void *m = NULL;
317 
318 	spin_lock_irqsave(&sym53c8xx_lock, flags);
319 	mp = ___get_dma_pool(dev_dmat);
320 	if (!mp)
321 		mp = ___cre_dma_pool(dev_dmat);
322 	if (!mp)
323 		goto out;
324 	m = __sym_calloc(mp, size, name);
325 #ifdef	SYM_MEM_FREE_UNUSED
326 	if (!mp->nump)
327 		___del_dma_pool(mp);
328 #endif
329 
330  out:
331 	spin_unlock_irqrestore(&sym53c8xx_lock, flags);
332 	return m;
333 }
334 
335 void __sym_mfree_dma(m_pool_ident_t dev_dmat, void *m, int size, char *name)
336 {
337 	unsigned long flags;
338 	m_pool_p mp;
339 
340 	spin_lock_irqsave(&sym53c8xx_lock, flags);
341 	mp = ___get_dma_pool(dev_dmat);
342 	if (!mp)
343 		goto out;
344 	__sym_mfree(mp, m, size, name);
345 #ifdef	SYM_MEM_FREE_UNUSED
346 	if (!mp->nump)
347 		___del_dma_pool(mp);
348 #endif
349  out:
350 	spin_unlock_irqrestore(&sym53c8xx_lock, flags);
351 }
352 
353 /*
354  *  Actual virtual to bus physical address translator
355  *  for 32 bit addressable DMAable memory.
356  */
357 dma_addr_t __vtobus(m_pool_ident_t dev_dmat, void *m)
358 {
359 	unsigned long flags;
360 	m_pool_p mp;
361 	int hc = VTOB_HASH_CODE(m);
362 	m_vtob_p vp = NULL;
363 	void *a = (void *)((unsigned long)m & ~SYM_MEM_CLUSTER_MASK);
364 	dma_addr_t b;
365 
366 	spin_lock_irqsave(&sym53c8xx_lock, flags);
367 	mp = ___get_dma_pool(dev_dmat);
368 	if (mp) {
369 		vp = mp->vtob[hc];
370 		while (vp && vp->vaddr != a)
371 			vp = vp->next;
372 	}
373 	if (!vp)
374 		panic("sym: VTOBUS FAILED!\n");
375 	b = vp->baddr + (m - a);
376 	spin_unlock_irqrestore(&sym53c8xx_lock, flags);
377 	return b;
378 }
379