nandsim_swap.c revision 235537
1/*-
2 * Copyright (C) 2009-2012 Semihalf
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/dev/nand/nandsim_swap.c 235537 2012-05-17 10:11:18Z gber $");
29
30#include <sys/param.h>
31#include <sys/types.h>
32#include <sys/systm.h>
33#include <sys/malloc.h>
34#include <sys/queue.h>
35#include <sys/fcntl.h>
36#include <sys/proc.h>
37#include <sys/namei.h>
38#include <sys/lock.h>
39#include <sys/vnode.h>
40#include <sys/mount.h>
41
42#include <dev/nand/nandsim_chip.h>
43#include <dev/nand/nandsim_swap.h>
44
45static int  init_block_state(struct chip_swap *);
46static void destroy_block_state(struct chip_swap *);
47
48static int  create_buffers(struct chip_swap *);
49static void destroy_buffers(struct chip_swap *);
50
51static int  swap_file_open(struct chip_swap *, const char *);
52static void swap_file_close(struct chip_swap *);
53static int  swap_file_write(struct chip_swap *, struct block_state *);
54static int  swap_file_read(struct chip_swap *, struct block_state *);
55
56#define	CHIP_SWAP_CMODE		0600
57#define	CHIP_SWAP_BLOCKSPACES	2
58
59static int
60init_block_state(struct chip_swap *swap)
61{
62	struct block_state *blk_state;
63	int i;
64
65	if (swap == NULL)
66		return (-1);
67
68	blk_state = malloc(swap->nof_blks * sizeof(struct block_state),
69	    M_NANDSIM, M_WAITOK | M_ZERO);
70
71	for (i = 0; i < swap->nof_blks; i++)
72		blk_state[i].offset = 0xffffffff;
73
74	swap->blk_state = blk_state;
75
76	return (0);
77}
78
79static void
80destroy_block_state(struct chip_swap *swap)
81{
82
83	if (swap == NULL)
84		return;
85
86	if (swap->blk_state != NULL)
87		free(swap->blk_state, M_NANDSIM);
88}
89
90static int
91create_buffers(struct chip_swap *swap)
92{
93	struct block_space *block_space;
94	void *block;
95	int i;
96
97	for (i = 0; i < CHIP_SWAP_BLOCKSPACES; i++) {
98		block_space = malloc(sizeof(*block_space), M_NANDSIM, M_WAITOK);
99		block = malloc(swap->blk_size, M_NANDSIM, M_WAITOK);
100		block_space->blk_ptr = block;
101		SLIST_INSERT_HEAD(&swap->free_bs, block_space, free_link);
102		nand_debug(NDBG_SIM,"created blk_space %p[%p]\n", block_space,
103		    block);
104	}
105
106	if (i == 0)
107		return (-1);
108
109	return (0);
110}
111
112static void
113destroy_buffers(struct chip_swap *swap)
114{
115	struct block_space *blk_space;
116
117	if (swap == NULL)
118		return;
119
120	blk_space = SLIST_FIRST(&swap->free_bs);
121	while (blk_space) {
122		SLIST_REMOVE_HEAD(&swap->free_bs, free_link);
123		nand_debug(NDBG_SIM,"destroyed blk_space %p[%p]\n",
124		    blk_space, blk_space->blk_ptr);
125		free(blk_space->blk_ptr, M_NANDSIM);
126		free(blk_space, M_NANDSIM);
127		blk_space = SLIST_FIRST(&swap->free_bs);
128	}
129
130	blk_space = STAILQ_FIRST(&swap->used_bs);
131	while (blk_space) {
132		STAILQ_REMOVE_HEAD(&swap->used_bs, used_link);
133		nand_debug(NDBG_SIM,"destroyed blk_space %p[%p]\n",
134		    blk_space, blk_space->blk_ptr);
135		free(blk_space->blk_ptr, M_NANDSIM);
136		free(blk_space, M_NANDSIM);
137		blk_space = STAILQ_FIRST(&swap->used_bs);
138	}
139}
140
141static int
142swap_file_open(struct chip_swap *swap, const char *swap_file)
143{
144	struct nameidata nd;
145	int vfslocked, flags, error;
146
147	NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, swap_file,
148	    curthread);
149
150	flags = FWRITE | FREAD | O_NOFOLLOW | O_CREAT | O_TRUNC;
151
152	error = vn_open(&nd, &flags, CHIP_SWAP_CMODE, NULL);
153	if (error) {
154		nand_debug(NDBG_SIM,"Cannot create swap file %s", swap_file);
155		NDFREE(&nd, NDF_ONLY_PNBUF);
156		return (error);
157	}
158
159	swap->swap_cred = crhold(curthread->td_ucred);
160	vfslocked = NDHASGIANT(&nd);
161	NDFREE(&nd, NDF_ONLY_PNBUF);
162
163	/* We just unlock so we hold a reference */
164	VOP_UNLOCK(nd.ni_vp, 0);
165	VFS_UNLOCK_GIANT(vfslocked);
166
167	swap->swap_vp = nd.ni_vp;
168
169	return (0);
170}
171
172static void
173swap_file_close(struct chip_swap *swap)
174{
175
176	if (swap == NULL)
177		return;
178
179	if (swap->swap_vp == NULL)
180		return;
181
182	vn_close(swap->swap_vp, FWRITE, swap->swap_cred, curthread);
183	crfree(swap->swap_cred);
184}
185
186static int
187swap_file_write(struct chip_swap *swap, struct block_state *blk_state)
188{
189	struct block_space *blk_space;
190	struct thread *td;
191	struct mount *mp;
192	struct vnode *vp;
193	struct uio auio;
194	struct iovec aiov;
195	int vfslocked;
196
197	if (swap == NULL || blk_state == NULL)
198		return (-1);
199
200	blk_space = blk_state->blk_sp;
201	if (blk_state->offset == -1) {
202		blk_state->offset = swap->swap_offset;
203		swap->swap_offset += swap->blk_size;
204	}
205
206	nand_debug(NDBG_SIM,"saving %p[%p] at %x\n",
207	    blk_space, blk_space->blk_ptr, blk_state->offset);
208
209	bzero(&aiov, sizeof(aiov));
210	bzero(&auio, sizeof(auio));
211
212	aiov.iov_base = blk_space->blk_ptr;
213	aiov.iov_len = swap->blk_size;
214	td = curthread;
215	vp = swap->swap_vp;
216
217	auio.uio_iov = &aiov;
218	auio.uio_offset = blk_state->offset;
219	auio.uio_segflg = UIO_SYSSPACE;
220	auio.uio_rw = UIO_WRITE;
221	auio.uio_iovcnt = 1;
222	auio.uio_resid = swap->blk_size;
223	auio.uio_td = td;
224
225	vfslocked = VFS_LOCK_GIANT(vp->v_mount);
226	vn_start_write(vp, &mp, V_WAIT);
227	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
228	VOP_WRITE(vp, &auio, IO_UNIT, swap->swap_cred);
229	VOP_UNLOCK(vp, 0);
230	vn_finished_write(mp);
231	VFS_UNLOCK_GIANT(vfslocked);
232
233	return (0);
234}
235
236static int
237swap_file_read(struct chip_swap *swap, struct block_state *blk_state)
238{
239	struct block_space *blk_space;
240	struct thread *td;
241	struct vnode *vp;
242	struct uio auio;
243	struct iovec aiov;
244	int vfslocked;
245
246	if (swap == NULL || blk_state == NULL)
247		return (-1);
248
249	blk_space = blk_state->blk_sp;
250
251	nand_debug(NDBG_SIM,"restore %p[%p] at %x\n",
252	    blk_space, blk_space->blk_ptr, blk_state->offset);
253
254	bzero(&aiov, sizeof(aiov));
255	bzero(&auio, sizeof(auio));
256
257	aiov.iov_base = blk_space->blk_ptr;
258	aiov.iov_len = swap->blk_size;
259	td = curthread;
260	vp = swap->swap_vp;
261
262	auio.uio_iov = &aiov;
263	auio.uio_offset = blk_state->offset;
264	auio.uio_segflg = UIO_SYSSPACE;
265	auio.uio_rw = UIO_READ;
266	auio.uio_iovcnt = 1;
267	auio.uio_resid = swap->blk_size;
268	auio.uio_td = td;
269
270	vfslocked = VFS_LOCK_GIANT(vp->v_mount);
271	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
272	VOP_READ(vp, &auio, 0, swap->swap_cred);
273	VOP_UNLOCK(vp, 0);
274	VFS_UNLOCK_GIANT(vfslocked);
275
276	return (0);
277}
278
279struct chip_swap *
280nandsim_swap_init(const char *swap_file, uint32_t nof_blks, uint32_t blk_size)
281{
282	struct chip_swap *swap;
283	int err = 0;
284
285	if ((swap_file == NULL) || (nof_blks == 0) || (blk_size == 0))
286		return (NULL);
287
288	swap = malloc(sizeof(*swap), M_NANDSIM, M_WAITOK | M_ZERO);
289
290	SLIST_INIT(&swap->free_bs);
291	STAILQ_INIT(&swap->used_bs);
292	swap->blk_size = blk_size;
293	swap->nof_blks = nof_blks;
294
295	err = init_block_state(swap);
296	if (err) {
297		nandsim_swap_destroy(swap);
298		return (NULL);
299	}
300
301	err = create_buffers(swap);
302	if (err) {
303		nandsim_swap_destroy(swap);
304		return (NULL);
305	}
306
307	err = swap_file_open(swap, swap_file);
308	if (err) {
309		nandsim_swap_destroy(swap);
310		return (NULL);
311	}
312
313	return (swap);
314}
315
316void
317nandsim_swap_destroy(struct chip_swap *swap)
318{
319
320	if (swap == NULL)
321		return;
322
323	destroy_block_state(swap);
324	destroy_buffers(swap);
325	swap_file_close(swap);
326	free(swap, M_NANDSIM);
327}
328
329struct block_space *
330get_bs(struct chip_swap *swap, uint32_t block, uint8_t writing)
331{
332	struct block_state *blk_state, *old_blk_state = NULL;
333	struct block_space *blk_space;
334
335	if (swap == NULL || (block >= swap->nof_blks))
336		return (NULL);
337
338	blk_state = &swap->blk_state[block];
339	nand_debug(NDBG_SIM,"blk_state %x\n", blk_state->status);
340
341	if (blk_state->status & BLOCK_ALLOCATED) {
342		blk_space = blk_state->blk_sp;
343	} else {
344		blk_space = SLIST_FIRST(&swap->free_bs);
345		if (blk_space) {
346			SLIST_REMOVE_HEAD(&swap->free_bs, free_link);
347			STAILQ_INSERT_TAIL(&swap->used_bs, blk_space,
348			    used_link);
349		} else {
350			blk_space = STAILQ_FIRST(&swap->used_bs);
351			old_blk_state = blk_space->blk_state;
352			STAILQ_REMOVE_HEAD(&swap->used_bs, used_link);
353			STAILQ_INSERT_TAIL(&swap->used_bs, blk_space,
354			    used_link);
355			if (old_blk_state->status & BLOCK_DIRTY) {
356				swap_file_write(swap, old_blk_state);
357				old_blk_state->status &= ~BLOCK_DIRTY;
358				old_blk_state->status |= BLOCK_SWAPPED;
359			}
360		}
361	}
362
363	if (blk_space == NULL)
364		return (NULL);
365
366	if (old_blk_state != NULL) {
367		old_blk_state->status &= ~BLOCK_ALLOCATED;
368		old_blk_state->blk_sp = NULL;
369	}
370
371	blk_state->blk_sp = blk_space;
372	blk_space->blk_state = blk_state;
373
374	if (!(blk_state->status & BLOCK_ALLOCATED)) {
375		if (blk_state->status & BLOCK_SWAPPED)
376			swap_file_read(swap, blk_state);
377		else
378			memset(blk_space->blk_ptr, 0xff, swap->blk_size);
379		blk_state->status |= BLOCK_ALLOCATED;
380	}
381
382	if (writing)
383		blk_state->status |= BLOCK_DIRTY;
384
385	nand_debug(NDBG_SIM,"get_bs returned %p[%p] state %x\n", blk_space,
386	    blk_space->blk_ptr, blk_state->status);
387
388	return (blk_space);
389}
390