3 * ===================================
4 * HARP | Host ATM Research Platform
5 * ===================================
8 * This Host ATM Research Platform ("HARP") file (the "Software") is
9 * made available by Network Computing Services, Inc. ("NetworkCS")
10 * "AS IS". NetworkCS does not provide maintenance, improvements or
11 * support of any kind.
13 * NETWORKCS MAKES NO WARRANTIES OR REPRESENTATIONS, EXPRESS OR IMPLIED,
14 * INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY
15 * AND FITNESS FOR A PARTICULAR PURPOSE, AS TO ANY ELEMENT OF THE
16 * SOFTWARE OR ANY SUPPORT PROVIDED IN CONNECTION WITH THIS SOFTWARE.
17 * In no event shall NetworkCS be responsible for any damages, including
18 * but not limited to consequential damages, arising from or relating to
19 * any use of the Software or related support.
21 * Copyright 1994-1998 Network Computing Services, Inc.
23 * Copies of this Software may be made, however, the above copyright
24 * notice must be reproduced on all copies.
26 * @(#) $FreeBSD: src/sys/dev/hea/eni_buffer.c,v 1.5 1999/08/28 00:41:43 peter Exp $
27 * @(#) $DragonFly: src/sys/dev/atm/hea/eni_buffer.c,v 1.6 2004/05/13 19:44:28 dillon Exp $
31 * Efficient ENI Adapter Support
32 * -----------------------------
34 * Handle adapter memory buffers for ENI adapters
38 #include <netproto/atm/kern_include.h>
40 #include "eni_stats.h"
44 static int eni_test_memory (Eni_unit *);
47 * The host is going to manage (that is, allocate and free) buffers
48 * in the adapters RAM space. We are going to implement this as a
49 * linked list describing FREE and INUSE memory segments. Initially,
50 * the list contains one element with all memory marked free. As requests
51 * are made, we search the list until we find the first free element
52 * which can satisfy the request. If necessary, we will break the free
53 * element into an INUSE element, and a new FREE element. When freeing
54 * memory, we look at adjacent elements and if one or more are free,
55 * we will combine into a single larger FREE element.
59 * This is for testing purposes. Since there are two versions of
60 * the Efficient adapter with different memory sizes, this allows
61 * us to fool an adapter with more memory into thinking it has less.
63 static int eni_mem_max = MAX_ENI_MEM; /* Default to all available memory */
66 * Size and test adapter RAM
68 * Walk through adapter RAM writing known patterns and reading back
69 * for comparison. We write more than one pattern on the off chance
70 * that we "get lucky" and read what we expected.
73 * eup pointer to device unit structure
76 * size memory size in bytes
79 eni_test_memory ( eup )
87 * Walk through to maximum looking for RAM
89 for ( i = 0; i < MAX_ENI_MEM; i += TEST_STEP ) {
90 mp = (Eni_mem)((int)eup->eu_ram + i);
92 *mp = (u_long)TEST_PAT;
93 /* read pattern, match? */
94 if ( *mp == (u_long)TEST_PAT ) {
95 /* yes - write inverse pattern */
96 *mp = (u_long)~TEST_PAT;
97 /* read pattern, match? */
98 if ( *mp == (u_long)~TEST_PAT ) {
99 /* yes - assume another 1K available */
100 ram_size = i + TEST_STEP;
107 * Clear all RAM to initial value of zero.
108 * This makes sure we don't leave anything funny in the
111 KM_ZERO ( eup->eu_ram, ram_size );
114 * If we'd like to claim to have less memory, here's where
115 * we do so. We take the minimum of what we'd like and what
116 * we really found on the adapter.
118 ram_size = MIN ( ram_size, eni_mem_max );
125 * Initialize our memory allocator.
128 * eup Pointer to per unit structure
131 * size Physical RAM size
132 * -1 failed to initialize memory
136 eni_init_memory ( eup )
141 * Have we (somehow) been called before?
143 if ( eup->eu_memmap != NULL )
145 /* Oops - it's already been initialized */
150 * Allocate initial element which will hold all of memory
152 eup->eu_memmap = (Mbd *)KM_ALLOC(sizeof(Mbd), M_DEVBUF, M_WAITOK);
155 * Test and size memory
157 eup->eu_ramsize = eni_test_memory ( eup );
160 * Initialize a one element list which contains
163 eup->eu_memmap->prev = eup->eu_memmap->next = NULL;
164 eup->eu_memmap->base = (caddr_t)SEGBUF_BASE;
165 eup->eu_memmap->size = eup->eu_ramsize - SEGBUF_BASE;
166 eup->eu_memmap->state = MEM_FREE;
168 return ( eup->eu_ramsize );
172 * Allocate a buffer from adapter RAM. Due to constraints on the card,
173 * we may roundup the size request to the next largest chunksize. Note
174 * also that we must pay attention to address alignment within adapter
178 * eup pointer to per unit structure
179 * size pointer to requested size - in bytes
182 * addr address relative to adapter of allocated memory
183 * size modified to reflect actual size of buffer
187 eni_allocate_buffer ( eup, size )
193 Mbd *eptr = eup->eu_memmap;
196 * Initial size requested
201 * Find the buffer size which will hold this request. There
202 * are 8 possible sizes, each a power of two up, starting at
203 * 256 words or 1024 bytes.
205 for ( nclicks = 0; nclicks < ENI_BUF_NBIT; nclicks++ )
206 if ( ( 1 << nclicks ) * ENI_BUF_PGSZ >= nsize )
210 * Request was for larger then the card supports
212 if ( nclicks >= ENI_BUF_NBIT ) {
213 eup->eu_stats.eni_st_drv.drv_mm_toobig++;
214 /* Indicate 0 bytes allocated */
216 /* Return NULL buffer */
217 return ( (caddr_t)NULL );
221 * New size will be buffer size
223 nsize = ( 1 << nclicks ) * ENI_BUF_PGSZ;
226 * Look through memory for a segment large enough to
231 * State must be FREE and size must hold request
233 if ( eptr->state == MEM_FREE && eptr->size >= nsize )
236 * Request will fit - now check if the
237 * alignment needs fixing
239 if ( ((u_int)eptr->base & (nsize-1)) != 0 )
244 * Calculate where the buffer would have to
245 * fall to be aligned.
247 nbase = (caddr_t)((u_int)( eptr->base + nsize ) &
250 * If we use this alignment, will it still fit?
252 if ( (eptr->size - (nbase - eptr->base)) >= 0 )
256 /* Yep - create a new segment */
257 etmp = (Mbd *)KM_ALLOC(sizeof(Mbd), M_DEVBUF, M_WAITOK);
258 /* Place it in the list */
259 etmp->next = eptr->next;
261 etmp->next->prev = etmp;
264 /* Fill in new base and size */
266 etmp->size = eptr->size - ( nbase - eptr->base );
267 /* Adjust old size */
268 eptr->size -= etmp->size;
270 etmp->state = MEM_FREE;
272 /* Done - outa here */
276 break; /* Alignment is okay - we're done */
278 /* Haven't found anything yet - keep looking */
284 /* Found a usable segment - grab what we need */
286 if ( eptr->size == nsize )
287 /* Mark it as INUSE */
288 eptr->state = MEM_INUSE;
292 /* larger then we need - split it */
294 etmp = (Mbd *)KM_ALLOC(sizeof(Mbd), M_DEVBUF, M_WAITOK);
295 /* Place new element in list */
296 etmp->next = eptr->next;
298 etmp->next->prev = etmp;
301 /* Set new base, size and state */
302 etmp->base = eptr->base + nsize;
303 etmp->size = eptr->size - nsize;
304 etmp->state = MEM_FREE;
305 /* Adjust size and state of element we intend to use */
307 eptr->state = MEM_INUSE;
311 /* After all that, did we find a usable buffer? */
314 /* Record another inuse buffer of this size */
316 eup->eu_memclicks[nclicks]++;
319 * Return true size of allocated buffer
323 * Make address relative to start of RAM since
324 * its (the address) for use by the adapter, not
327 return ((caddr_t)eptr->base);
329 eup->eu_stats.eni_st_drv.drv_mm_nobuf++;
330 /* No buffer to return - indicate zero length */
332 /* Return NULL buffer */
333 return ( (caddr_t)NULL );
338 * Procedure to release a buffer previously allocated from adapter
339 * RAM. When possible, we'll compact memory.
342 * eup pointer to per unit structure
343 * base base adapter address of buffer to be freed
350 eni_free_buffer ( eup, base )
354 Mbd *eptr = eup->eu_memmap;
357 /* Look through entire list */
360 /* Is this the buffer to be freed? */
361 if ( eptr->base == base )
364 * We're probably asking for trouble but,
367 if ( eptr->state != MEM_INUSE )
369 eup->eu_stats.eni_st_drv.drv_mm_notuse++;
370 /* Huh? Something's wrong */
373 /* Reset state to FREE */
374 eptr->state = MEM_FREE;
376 /* Determine size for stats info */
377 for ( nclicks = 0; nclicks < ENI_BUF_NBIT; nclicks++ )
378 if ( ( 1 << nclicks ) * ENI_BUF_PGSZ == eptr->size )
381 /* Valid size? Yes - decrement inuse count */
382 if ( nclicks < ENI_BUF_NBIT )
383 eup->eu_memclicks[nclicks]--;
385 /* Try to compact neighbors */
388 if ( eptr->prev->state == MEM_FREE )
391 /* Add to previous block */
392 eptr->prev->size += eptr->size;
393 /* Set prev block to skip this one */
394 eptr->prev->next = eptr->next;
395 /* Set next block to skip this one */
397 eptr->next->prev = eptr->prev;
398 /* Reset to where we want to be */
400 /* and free this element */
401 (void)KM_FREE(etmp, etmp->size, M_DEVBUF);
405 if ( eptr->next->state == MEM_FREE )
407 Mbd *etmp = eptr->next;
409 /* add following block in */
410 eptr->size += etmp->size;
411 /* set next next block to skip next block */
413 etmp->next->prev = eptr;
414 /* skip next block */
415 eptr->next = etmp->next;
416 /* and free next element */
417 (void)KM_FREE(etmp, etmp->size, M_DEVBUF);
420 * We've freed the buffer and done any compaction,
421 * we needn't look any further...
430 /* Oops - failed to find the buffer. This is BAD */
431 eup->eu_stats.eni_st_drv.drv_mm_notfnd++;