1 /*-
2 * Copyright (c) 1982, 1986 The Regents of the University of California.
3 * Copyright (c) 1989, 1990 William Jolitz
4 * Copyright (c) 1994 John Dyson
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * the Systems Programming Group of the University of Utah Computer
9 * Science Department, and William Jolitz.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
40 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
41 * $FreeBSD: releng/10.4/sys/powerpc/powerpc/vm_machdep.c 265952 2014-05-13 16:50:10Z ian $
42 */
43 /*-
44 * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
45 * All rights reserved.
46 *
47 * Author: Chris G. Demetriou
48 *
49 * Permission to use, copy, modify and distribute this software and
50 * its documentation is hereby granted, provided that both the copyright
51 * notice and this permission notice appear in all copies of the
52 * software, derivative works or modified versions, and any portions
53 * thereof, and that both notices appear in supporting documentation.
54 *
55 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
56 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
57 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
58 *
59 * Carnegie Mellon requests users of this software to return to
60 *
61 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
62 * School of Computer Science
63 * Carnegie Mellon University
64 * Pittsburgh PA 15213-3890
65 *
66 * any improvements or extensions that they make and grant Carnegie the
67 * rights to redistribute these changes.
68 */
69
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/proc.h>
73 #include <sys/malloc.h>
74 #include <sys/bio.h>
75 #include <sys/buf.h>
76 #include <sys/ktr.h>
77 #include <sys/lock.h>
78 #include <sys/mutex.h>
79 #include <sys/vnode.h>
80 #include <sys/vmmeter.h>
81 #include <sys/kernel.h>
82 #include <sys/mbuf.h>
83 #include <sys/sf_buf.h>
84 #include <sys/sysctl.h>
85 #include <sys/sysent.h>
86 #include <sys/unistd.h>
87
88 #include <machine/cpu.h>
89 #include <machine/fpu.h>
90 #include <machine/frame.h>
91 #include <machine/md_var.h>
92 #include <machine/pcb.h>
93
94 #include <dev/ofw/openfirm.h>
95
96 #include <vm/vm.h>
97 #include <vm/vm_param.h>
98 #include <vm/vm_kern.h>
99 #include <vm/vm_page.h>
100 #include <vm/vm_map.h>
101 #include <vm/vm_extern.h>
102
103 /*
104 * On systems without a direct mapped region (e.g. PPC64),
105 * we use the same code as the Book E implementation. Since
106 * we need to have runtime detection of this, define some machinery
107 * for sf_bufs in this case, and ignore it on systems with direct maps.
108 */
109
110 #ifndef NSFBUFS
111 #define NSFBUFS (512 + maxusers * 16)
112 #endif
113
114 static int nsfbufs;
115 static int nsfbufspeak;
116 static int nsfbufsused;
117
118 SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufs, CTLFLAG_RDTUN, &nsfbufs, 0,
119 "Maximum number of sendfile(2) sf_bufs available");
120 SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufspeak, CTLFLAG_RD, &nsfbufspeak, 0,
121 "Number of sendfile(2) sf_bufs at peak usage");
122 SYSCTL_INT(_kern_ipc, OID_AUTO, nsfbufsused, CTLFLAG_RD, &nsfbufsused, 0,
123 "Number of sendfile(2) sf_bufs in use");
124
125 static void sf_buf_init(void *arg);
126 SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL);
127
128 LIST_HEAD(sf_head, sf_buf);
129
130 /* A hash table of active sendfile(2) buffers */
131 static struct sf_head *sf_buf_active;
132 static u_long sf_buf_hashmask;
133
134 #define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask)
135
136 static TAILQ_HEAD(, sf_buf) sf_buf_freelist;
137 static u_int sf_buf_alloc_want;
138
139 /*
140 * A lock used to synchronize access to the hash table and free list
141 */
142 static struct mtx sf_buf_lock;
143
144 #ifdef __powerpc64__
145 extern uintptr_t tocbase;
146 #endif
147
148
149 /*
150 * Finish a fork operation, with process p2 nearly set up.
151 * Copy and update the pcb, set up the stack so that the child
152 * ready to run and return to user mode.
153 */
154 void
155 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
156 {
157 struct trapframe *tf;
158 struct callframe *cf;
159 struct pcb *pcb;
160
161 KASSERT(td1 == curthread || td1 == &thread0,
162 ("cpu_fork: p1 not curproc and not proc0"));
163 CTR3(KTR_PROC, "cpu_fork: called td1=%p p2=%p flags=%x",
164 td1, p2, flags);
165
166 if ((flags & RFPROC) == 0)
167 return;
168
169 pcb = (struct pcb *)((td2->td_kstack +
170 td2->td_kstack_pages * PAGE_SIZE - sizeof(struct pcb)) & ~0x2fUL);
171 td2->td_pcb = pcb;
172
173 /* Copy the pcb */
174 bcopy(td1->td_pcb, pcb, sizeof(struct pcb));
175
176 /*
177 * Create a fresh stack for the new process.
178 * Copy the trap frame for the return to user mode as if from a
179 * syscall. This copies most of the user mode register values.
180 */
181 tf = (struct trapframe *)pcb - 1;
182 bcopy(td1->td_frame, tf, sizeof(*tf));
183
184 /* Set up trap frame. */
185 tf->fixreg[FIRSTARG] = 0;
186 tf->fixreg[FIRSTARG + 1] = 0;
187 tf->cr &= ~0x10000000;
188
189 td2->td_frame = tf;
190
191 cf = (struct callframe *)tf - 1;
192 memset(cf, 0, sizeof(struct callframe));
193 #ifdef __powerpc64__
194 cf->cf_toc = tocbase;
195 #endif
196 cf->cf_func = (register_t)fork_return;
197 cf->cf_arg0 = (register_t)td2;
198 cf->cf_arg1 = (register_t)tf;
199
200 pcb->pcb_sp = (register_t)cf;
201 KASSERT(pcb->pcb_sp % 16 == 0, ("stack misaligned"));
202 #ifdef __powerpc64__
203 pcb->pcb_lr = ((register_t *)fork_trampoline)[0];
204 pcb->pcb_toc = ((register_t *)fork_trampoline)[1];
205 #else
206 pcb->pcb_lr = (register_t)fork_trampoline;
207 #endif
208 #ifdef AIM
209 pcb->pcb_cpu.aim.usr_vsid = 0;
210 #endif
211
212 /* Setup to release spin count in fork_exit(). */
213 td2->td_md.md_spinlock_count = 1;
214 td2->td_md.md_saved_msr = PSL_KERNSET;
215
216 /*
217 * Now cpu_switch() can schedule the new process.
218 */
219 }
220
221 /*
222 * Intercept the return address from a freshly forked process that has NOT
223 * been scheduled yet.
224 *
225 * This is needed to make kernel threads stay in kernel mode.
226 */
227 void
228 cpu_set_fork_handler(struct thread *td, void (*func)(void *), void *arg)
229 {
230 struct callframe *cf;
231
232 CTR4(KTR_PROC, "%s called with td=%p func=%p arg=%p",
233 __func__, td, func, arg);
234
235 cf = (struct callframe *)td->td_pcb->pcb_sp;
236
237 cf->cf_func = (register_t)func;
238 cf->cf_arg0 = (register_t)arg;
239 }
240
241 void
242 cpu_exit(struct thread *td)
243 {
244
245 }
246
247 /*
248 * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-))
249 */
250 static void
251 sf_buf_init(void *arg)
252 {
253 struct sf_buf *sf_bufs;
254 vm_offset_t sf_base;
255 int i;
256
257 /* Don't bother on systems with a direct map */
258 if (hw_direct_map)
259 return;
260
261 nsfbufs = NSFBUFS;
262 TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs);
263
264 sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask);
265 TAILQ_INIT(&sf_buf_freelist);
266 sf_base = kva_alloc(nsfbufs * PAGE_SIZE);
267 sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP,
268 M_NOWAIT | M_ZERO);
269
270 for (i = 0; i < nsfbufs; i++) {
271 sf_bufs[i].kva = sf_base + i * PAGE_SIZE;
272 TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry);
273 }
274 sf_buf_alloc_want = 0;
275 mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF);
276 }
277
278 /*
279 * Get an sf_buf from the freelist. Will block if none are available.
280 */
281 struct sf_buf *
282 sf_buf_alloc(struct vm_page *m, int flags)
283 {
284 struct sf_head *hash_list;
285 struct sf_buf *sf;
286 int error;
287
288 if (hw_direct_map) {
289 /* Shortcut the direct mapped case */
290 return ((struct sf_buf *)m);
291 }
292
293 hash_list = &sf_buf_active[SF_BUF_HASH(m)];
294 mtx_lock(&sf_buf_lock);
295 LIST_FOREACH(sf, hash_list, list_entry) {
296 if (sf->m == m) {
297 sf->ref_count++;
298 if (sf->ref_count == 1) {
299 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
300 nsfbufsused++;
301 nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
302 }
303 goto done;
304 }
305 }
306
307 while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) {
308 if (flags & SFB_NOWAIT)
309 goto done;
310
311 sf_buf_alloc_want++;
312 SFSTAT_INC(sf_allocwait);
313 error = msleep(&sf_buf_freelist, &sf_buf_lock,
314 (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0);
315 sf_buf_alloc_want--;
316
317 /*
318 * If we got a signal, don't risk going back to sleep.
319 */
320 if (error)
321 goto done;
322 }
323
324 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry);
325 if (sf->m != NULL)
326 LIST_REMOVE(sf, list_entry);
327
328 LIST_INSERT_HEAD(hash_list, sf, list_entry);
329 sf->ref_count = 1;
330 sf->m = m;
331 nsfbufsused++;
332 nsfbufspeak = imax(nsfbufspeak, nsfbufsused);
333 pmap_qenter(sf->kva, &sf->m, 1);
334 done:
335 mtx_unlock(&sf_buf_lock);
336 return (sf);
337 }
338
339 /*
340 * Detach mapped page and release resources back to the system.
341 *
342 * Remove a reference from the given sf_buf, adding it to the free
343 * list when its reference count reaches zero. A freed sf_buf still,
344 * however, retains its virtual-to-physical mapping until it is
345 * recycled or reactivated by sf_buf_alloc(9).
346 */
347 void
348 sf_buf_free(struct sf_buf *sf)
349 {
350 if (hw_direct_map)
351 return;
352
353 mtx_lock(&sf_buf_lock);
354 sf->ref_count--;
355 if (sf->ref_count == 0) {
356 TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry);
357 nsfbufsused--;
358
359 if (sf_buf_alloc_want > 0)
360 wakeup(&sf_buf_freelist);
361 }
362 mtx_unlock(&sf_buf_lock);
363 }
364
365 /*
366 * Software interrupt handler for queued VM system processing.
367 */
368 void
369 swi_vm(void *dummy)
370 {
371
372 if (busdma_swi_pending != 0)
373 busdma_swi();
374 }
375
376 /*
377 * Tell whether this address is in some physical memory region.
378 * Currently used by the kernel coredump code in order to avoid
379 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
380 * or other unpredictable behaviour.
381 */
382 int
383 is_physical_memory(vm_offset_t addr)
384 {
385
386 /*
387 * stuff other tests for known memory-mapped devices (PCI?)
388 * here
389 */
390 return (1);
391 }
392
393 /*
394 * CPU threading functions related to the VM layer. These could be used
395 * to map the SLB bits required for the kernel stack instead of forcing a
396 * fixed-size KVA.
397 */
398
399 void
400 cpu_thread_swapin(struct thread *td)
401 {
402
403 }
404
405 void
406 cpu_thread_swapout(struct thread *td)
407 {
408
409 }
410
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