xref: /openbmc/linux/drivers/scsi/sym53c8xx_2/sym_malloc.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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 #ifdef __FreeBSD__
41 #include <dev/sym/sym_glue.h>
42 #else
43 #include "sym_glue.h"
44 #endif
45 
46 /*
47  *  Simple power of two buddy-like generic allocator.
48  *  Provides naturally aligned memory chunks.
49  *
50  *  This simple code is not intended to be fast, but to
51  *  provide power of 2 aligned memory allocations.
52  *  Since the SCRIPTS processor only supplies 8 bit arithmetic,
53  *  this allocator allows simple and fast address calculations
54  *  from the SCRIPTS code. In addition, cache line alignment
55  *  is guaranteed for power of 2 cache line size.
56  *
57  *  This allocator has been developped for the Linux sym53c8xx
58  *  driver, since this O/S does not provide naturally aligned
59  *  allocations.
60  *  It has the advantage of allowing the driver to use private
61  *  pages of memory that will be useful if we ever need to deal
62  *  with IO MMUs for PCI.
63  */
64 static void *___sym_malloc(m_pool_p mp, int size)
65 {
66 	int i = 0;
67 	int s = (1 << SYM_MEM_SHIFT);
68 	int j;
69 	void *a;
70 	m_link_p h = mp->h;
71 
72 	if (size > SYM_MEM_CLUSTER_SIZE)
73 		return NULL;
74 
75 	while (size > s) {
76 		s <<= 1;
77 		++i;
78 	}
79 
80 	j = i;
81 	while (!h[j].next) {
82 		if (s == SYM_MEM_CLUSTER_SIZE) {
83 			h[j].next = (m_link_p) M_GET_MEM_CLUSTER();
84 			if (h[j].next)
85 				h[j].next->next = NULL;
86 			break;
87 		}
88 		++j;
89 		s <<= 1;
90 	}
91 	a = h[j].next;
92 	if (a) {
93 		h[j].next = h[j].next->next;
94 		while (j > i) {
95 			j -= 1;
96 			s >>= 1;
97 			h[j].next = (m_link_p) (a+s);
98 			h[j].next->next = NULL;
99 		}
100 	}
101 #ifdef DEBUG
102 	printf("___sym_malloc(%d) = %p\n", size, (void *) a);
103 #endif
104 	return a;
105 }
106 
107 /*
108  *  Counter-part of the generic allocator.
109  */
110 static void ___sym_mfree(m_pool_p mp, void *ptr, int size)
111 {
112 	int i = 0;
113 	int s = (1 << SYM_MEM_SHIFT);
114 	m_link_p q;
115 	unsigned long a, b;
116 	m_link_p h = mp->h;
117 
118 #ifdef DEBUG
119 	printf("___sym_mfree(%p, %d)\n", ptr, size);
120 #endif
121 
122 	if (size > SYM_MEM_CLUSTER_SIZE)
123 		return;
124 
125 	while (size > s) {
126 		s <<= 1;
127 		++i;
128 	}
129 
130 	a = (unsigned long)ptr;
131 
132 	while (1) {
133 		if (s == SYM_MEM_CLUSTER_SIZE) {
134 #ifdef SYM_MEM_FREE_UNUSED
135 			M_FREE_MEM_CLUSTER((void *)a);
136 #else
137 			((m_link_p) a)->next = h[i].next;
138 			h[i].next = (m_link_p) a;
139 #endif
140 			break;
141 		}
142 		b = a ^ s;
143 		q = &h[i];
144 		while (q->next && q->next != (m_link_p) b) {
145 			q = q->next;
146 		}
147 		if (!q->next) {
148 			((m_link_p) a)->next = h[i].next;
149 			h[i].next = (m_link_p) a;
150 			break;
151 		}
152 		q->next = q->next->next;
153 		a = a & b;
154 		s <<= 1;
155 		++i;
156 	}
157 }
158 
159 /*
160  *  Verbose and zeroing allocator that wrapps to the generic allocator.
161  */
162 static void *__sym_calloc2(m_pool_p mp, int size, char *name, int uflags)
163 {
164 	void *p;
165 
166 	p = ___sym_malloc(mp, size);
167 
168 	if (DEBUG_FLAGS & DEBUG_ALLOC) {
169 		printf ("new %-10s[%4d] @%p.\n", name, size, p);
170 	}
171 
172 	if (p)
173 		memset(p, 0, size);
174 	else if (uflags & SYM_MEM_WARN)
175 		printf ("__sym_calloc2: failed to allocate %s[%d]\n", name, size);
176 	return p;
177 }
178 #define __sym_calloc(mp, s, n)	__sym_calloc2(mp, s, n, SYM_MEM_WARN)
179 
180 /*
181  *  Its counter-part.
182  */
183 static void __sym_mfree(m_pool_p mp, void *ptr, int size, char *name)
184 {
185 	if (DEBUG_FLAGS & DEBUG_ALLOC)
186 		printf ("freeing %-10s[%4d] @%p.\n", name, size, ptr);
187 
188 	___sym_mfree(mp, ptr, size);
189 }
190 
191 /*
192  *  Default memory pool we donnot need to involve in DMA.
193  *
194  *  With DMA abstraction, we use functions (methods), to
195  *  distinguish between non DMAable memory and DMAable memory.
196  */
197 static void *___mp0_get_mem_cluster(m_pool_p mp)
198 {
199 	void *m = sym_get_mem_cluster();
200 	if (m)
201 		++mp->nump;
202 	return m;
203 }
204 
205 #ifdef	SYM_MEM_FREE_UNUSED
206 static void ___mp0_free_mem_cluster(m_pool_p mp, void *m)
207 {
208 	sym_free_mem_cluster(m);
209 	--mp->nump;
210 }
211 #else
212 #define ___mp0_free_mem_cluster NULL
213 #endif
214 
215 static struct sym_m_pool mp0 = {
216 	NULL,
217 	___mp0_get_mem_cluster,
218 	___mp0_free_mem_cluster
219 };
220 
221 /*
222  *  Methods that maintains DMAable pools according to user allocations.
223  *  New pools are created on the fly when a new pool id is provided.
224  *  They are deleted on the fly when they get emptied.
225  */
226 /* Get a memory cluster that matches the DMA constraints of a given pool */
227 static void * ___get_dma_mem_cluster(m_pool_p mp)
228 {
229 	m_vtob_p vbp;
230 	void *vaddr;
231 
232 	vbp = __sym_calloc(&mp0, sizeof(*vbp), "VTOB");
233 	if (!vbp)
234 		goto out_err;
235 
236 	vaddr = sym_m_get_dma_mem_cluster(mp, vbp);
237 	if (vaddr) {
238 		int hc = VTOB_HASH_CODE(vaddr);
239 		vbp->next = mp->vtob[hc];
240 		mp->vtob[hc] = vbp;
241 		++mp->nump;
242 	}
243 	return vaddr;
244 out_err:
245 	return NULL;
246 }
247 
248 #ifdef	SYM_MEM_FREE_UNUSED
249 /* Free a memory cluster and associated resources for DMA */
250 static void ___free_dma_mem_cluster(m_pool_p mp, void *m)
251 {
252 	m_vtob_p *vbpp, vbp;
253 	int hc = VTOB_HASH_CODE(m);
254 
255 	vbpp = &mp->vtob[hc];
256 	while (*vbpp && (*vbpp)->vaddr != m)
257 		vbpp = &(*vbpp)->next;
258 	if (*vbpp) {
259 		vbp = *vbpp;
260 		*vbpp = (*vbpp)->next;
261 		sym_m_free_dma_mem_cluster(mp, vbp);
262 		__sym_mfree(&mp0, vbp, sizeof(*vbp), "VTOB");
263 		--mp->nump;
264 	}
265 }
266 #endif
267 
268 /* Fetch the memory pool for a given pool id (i.e. DMA constraints) */
269 static __inline m_pool_p ___get_dma_pool(m_pool_ident_t dev_dmat)
270 {
271 	m_pool_p mp;
272 	for (mp = mp0.next;
273 		mp && !sym_m_pool_match(mp->dev_dmat, dev_dmat);
274 			mp = mp->next);
275 	return mp;
276 }
277 
278 /* Create a new memory DMAable pool (when fetch failed) */
279 static m_pool_p ___cre_dma_pool(m_pool_ident_t dev_dmat)
280 {
281 	m_pool_p mp = __sym_calloc(&mp0, sizeof(*mp), "MPOOL");
282 	if (mp) {
283 		mp->dev_dmat = dev_dmat;
284 		mp->get_mem_cluster = ___get_dma_mem_cluster;
285 #ifdef	SYM_MEM_FREE_UNUSED
286 		mp->free_mem_cluster = ___free_dma_mem_cluster;
287 #endif
288 		mp->next = mp0.next;
289 		mp0.next = mp;
290 		return mp;
291 	}
292 	return NULL;
293 }
294 
295 #ifdef	SYM_MEM_FREE_UNUSED
296 /* Destroy a DMAable memory pool (when got emptied) */
297 static void ___del_dma_pool(m_pool_p p)
298 {
299 	m_pool_p *pp = &mp0.next;
300 
301 	while (*pp && *pp != p)
302 		pp = &(*pp)->next;
303 	if (*pp) {
304 		*pp = (*pp)->next;
305 		__sym_mfree(&mp0, p, sizeof(*p), "MPOOL");
306 	}
307 }
308 #endif
309 
310 /* This lock protects only the memory allocation/free.  */
311 static DEFINE_SPINLOCK(sym53c8xx_lock);
312 
313 /*
314  *  Actual allocator for DMAable memory.
315  */
316 void *__sym_calloc_dma(m_pool_ident_t dev_dmat, int size, char *name)
317 {
318 	unsigned long flags;
319 	m_pool_p mp;
320 	void *m = NULL;
321 
322 	spin_lock_irqsave(&sym53c8xx_lock, flags);
323 	mp = ___get_dma_pool(dev_dmat);
324 	if (!mp)
325 		mp = ___cre_dma_pool(dev_dmat);
326 	if (!mp)
327 		goto out;
328 	m = __sym_calloc(mp, size, name);
329 #ifdef	SYM_MEM_FREE_UNUSED
330 	if (!mp->nump)
331 		___del_dma_pool(mp);
332 #endif
333 
334  out:
335 	spin_unlock_irqrestore(&sym53c8xx_lock, flags);
336 	return m;
337 }
338 
339 void __sym_mfree_dma(m_pool_ident_t dev_dmat, void *m, int size, char *name)
340 {
341 	unsigned long flags;
342 	m_pool_p mp;
343 
344 	spin_lock_irqsave(&sym53c8xx_lock, flags);
345 	mp = ___get_dma_pool(dev_dmat);
346 	if (!mp)
347 		goto out;
348 	__sym_mfree(mp, m, size, name);
349 #ifdef	SYM_MEM_FREE_UNUSED
350 	if (!mp->nump)
351 		___del_dma_pool(mp);
352 #endif
353  out:
354 	spin_unlock_irqrestore(&sym53c8xx_lock, flags);
355 }
356 
357 /*
358  *  Actual virtual to bus physical address translator
359  *  for 32 bit addressable DMAable memory.
360  */
361 dma_addr_t __vtobus(m_pool_ident_t dev_dmat, void *m)
362 {
363 	unsigned long flags;
364 	m_pool_p mp;
365 	int hc = VTOB_HASH_CODE(m);
366 	m_vtob_p vp = NULL;
367 	void *a = (void *)((unsigned long)m & ~SYM_MEM_CLUSTER_MASK);
368 	dma_addr_t b;
369 
370 	spin_lock_irqsave(&sym53c8xx_lock, flags);
371 	mp = ___get_dma_pool(dev_dmat);
372 	if (mp) {
373 		vp = mp->vtob[hc];
374 		while (vp && vp->vaddr != a)
375 			vp = vp->next;
376 	}
377 	if (!vp)
378 		panic("sym: VTOBUS FAILED!\n");
379 	b = vp->baddr + (m - a);
380 	spin_unlock_irqrestore(&sym53c8xx_lock, flags);
381 	return b;
382 }
383