1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2011 Nathan Whitehorn
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/systm.h>
37 #include <sys/proc.h>
38
39 #include <vm/vm.h>
40 #include <vm/vm_page.h>
41 #include <vm/pmap.h>
42
43 #include <machine/bus.h>
44 #include <machine/md_var.h>
45 #include <machine/pcb.h>
46 #include <machine/rtas.h>
47 #include <machine/stdarg.h>
48
49 #include <dev/ofw/openfirm.h>
50
51 static MALLOC_DEFINE(M_RTAS, "rtas", "Run Time Abstraction Service");
52
53 static vm_offset_t rtas_bounce_phys;
54 static caddr_t rtas_bounce_virt;
55 static off_t rtas_bounce_offset;
56 static size_t rtas_bounce_size;
57 static uintptr_t rtas_private_data;
58 static struct mtx rtas_mtx;
59 static phandle_t rtas;
60
61 /* From ofwcall.S */
62 int rtascall(vm_offset_t callbuffer, uintptr_t rtas_privdat);
63 extern uintptr_t rtas_entry;
64 extern register_t rtasmsr;
65
66 /*
67 * After the VM is up, allocate RTAS memory and instantiate it
68 */
69
70 static void rtas_setup(void *);
71
72 SYSINIT(rtas_setup, SI_SUB_KMEM, SI_ORDER_ANY, rtas_setup, NULL);
73
74 static void
rtas_setup(void * junk)75 rtas_setup(void *junk)
76 {
77 ihandle_t rtasi;
78 cell_t rtas_size = 0, rtas_ptr;
79 char path[31];
80 int result;
81
82 rtas = OF_finddevice("/rtas");
83 if (rtas == -1) {
84 rtas = 0;
85 return;
86 }
87 OF_package_to_path(rtas, path, sizeof(path));
88
89 mtx_init(&rtas_mtx, "RTAS", NULL, MTX_SPIN);
90
91 /* RTAS must be called with everything turned off in MSR */
92 rtasmsr = mfmsr();
93 rtasmsr &= ~(PSL_IR | PSL_DR | PSL_EE | PSL_SE);
94 #ifdef __powerpc64__
95 rtasmsr &= ~PSL_SF;
96 #endif
97
98 /*
99 * Allocate rtas_size + one page of contiguous, wired physical memory
100 * that can fit into a 32-bit address space and accessed from real mode.
101 * This is used both to bounce arguments and for RTAS private data.
102 *
103 * It must be 4KB-aligned and not cross a 256 MB boundary.
104 */
105
106 OF_getencprop(rtas, "rtas-size", &rtas_size, sizeof(rtas_size));
107 rtas_size = round_page(rtas_size);
108 rtas_bounce_virt = contigmalloc(rtas_size + PAGE_SIZE, M_RTAS, 0, 0,
109 ulmin(platform_real_maxaddr(), BUS_SPACE_MAXADDR_32BIT),
110 4096, 256*1024*1024);
111
112 rtas_private_data = vtophys(rtas_bounce_virt);
113 rtas_bounce_virt += rtas_size; /* Actual bounce area */
114 rtas_bounce_phys = vtophys(rtas_bounce_virt);
115 rtas_bounce_size = PAGE_SIZE;
116
117 /*
118 * Instantiate RTAS. We always use the 32-bit version.
119 */
120
121 if (OF_hasprop(rtas, "linux,rtas-entry") &&
122 OF_hasprop(rtas, "linux,rtas-base")) {
123 OF_getencprop(rtas, "linux,rtas-base", &rtas_ptr,
124 sizeof(rtas_ptr));
125 rtas_private_data = rtas_ptr;
126 OF_getencprop(rtas, "linux,rtas-entry", &rtas_ptr,
127 sizeof(rtas_ptr));
128 } else {
129 rtasi = OF_open(path);
130 if (rtasi == 0) {
131 rtas = 0;
132 printf("Error initializing RTAS: could not open "
133 "node\n");
134 return;
135 }
136
137 result = OF_call_method("instantiate-rtas", rtasi, 1, 1,
138 (cell_t)rtas_private_data, &rtas_ptr);
139 OF_close(rtasi);
140
141 if (result != 0) {
142 rtas = 0;
143 rtas_ptr = 0;
144 printf("Error initializing RTAS (%d)\n", result);
145 return;
146 }
147 }
148
149 rtas_entry = (uintptr_t)(rtas_ptr);
150 }
151
152 static cell_t
rtas_real_map(const void * buf,size_t len)153 rtas_real_map(const void *buf, size_t len)
154 {
155 cell_t phys;
156
157 mtx_assert(&rtas_mtx, MA_OWNED);
158
159 /*
160 * Make sure the bounce page offset satisfies any reasonable
161 * alignment constraint.
162 */
163 rtas_bounce_offset += sizeof(register_t) -
164 (rtas_bounce_offset % sizeof(register_t));
165
166 if (rtas_bounce_offset + len > rtas_bounce_size) {
167 panic("Oversize RTAS call!");
168 return 0;
169 }
170
171 if (buf != NULL)
172 memcpy(rtas_bounce_virt + rtas_bounce_offset, buf, len);
173 else
174 return (0);
175
176 phys = rtas_bounce_phys + rtas_bounce_offset;
177 rtas_bounce_offset += len;
178
179 return (phys);
180 }
181
182 static void
rtas_real_unmap(cell_t physaddr,void * buf,size_t len)183 rtas_real_unmap(cell_t physaddr, void *buf, size_t len)
184 {
185 mtx_assert(&rtas_mtx, MA_OWNED);
186
187 if (physaddr == 0)
188 return;
189
190 memcpy(buf, rtas_bounce_virt + (physaddr - rtas_bounce_phys), len);
191 }
192
193 /* Check if we have RTAS */
194 int
rtas_exists(void)195 rtas_exists(void)
196 {
197 return (rtas != 0);
198 }
199
200 /* Call an RTAS method by token */
201 int
rtas_call_method(cell_t token,int nargs,int nreturns,...)202 rtas_call_method(cell_t token, int nargs, int nreturns, ...)
203 {
204 vm_offset_t argsptr;
205 jmp_buf env, *oldfaultbuf;
206 va_list ap;
207 struct {
208 cell_t token;
209 cell_t nargs;
210 cell_t nreturns;
211 cell_t args_n_results[12];
212 } args;
213 int n, result;
214
215 if (!rtas_exists() || nargs + nreturns > 12)
216 return (-1);
217
218 args.token = token;
219 va_start(ap, nreturns);
220
221 mtx_lock_spin(&rtas_mtx);
222 rtas_bounce_offset = 0;
223
224 args.nargs = nargs;
225 args.nreturns = nreturns;
226
227 for (n = 0; n < nargs; n++)
228 args.args_n_results[n] = va_arg(ap, cell_t);
229
230 argsptr = rtas_real_map(&args, sizeof(args));
231
232 /* Get rid of any stale machine checks that have been waiting. */
233 __asm __volatile ("sync; isync");
234 oldfaultbuf = curthread->td_pcb->pcb_onfault;
235 curthread->td_pcb->pcb_onfault = &env;
236 if (!setjmp(env)) {
237 __asm __volatile ("sync");
238 result = rtascall(argsptr, rtas_private_data);
239 __asm __volatile ("sync; isync");
240 } else {
241 result = RTAS_HW_ERROR;
242 }
243 curthread->td_pcb->pcb_onfault = oldfaultbuf;
244 __asm __volatile ("sync");
245
246 rtas_real_unmap(argsptr, &args, sizeof(args));
247 mtx_unlock_spin(&rtas_mtx);
248
249 if (result < 0)
250 return (result);
251
252 for (n = nargs; n < nargs + nreturns; n++)
253 *va_arg(ap, cell_t *) = args.args_n_results[n];
254 return (result);
255 }
256
257 /* Look up an RTAS token */
258 cell_t
rtas_token_lookup(const char * method)259 rtas_token_lookup(const char *method)
260 {
261 cell_t token;
262
263 if (!rtas_exists())
264 return (-1);
265
266 if (OF_getencprop(rtas, method, &token, sizeof(token)) == -1)
267 return (-1);
268
269 return (token);
270 }
271
272
273