1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/endian.h>
31 #include <sys/param.h>
32 #include <sys/kernel.h>
33 #include <sys/lock.h>
34 #include <sys/mutex.h>
35 #include <sys/systm.h>
36 #include <sys/proc.h>
37
38 #include <vm/vm.h>
39 #include <vm/vm_page.h>
40 #include <vm/pmap.h>
41
42 #include <machine/bus.h>
43 #include <machine/md_var.h>
44 #include <machine/pcb.h>
45 #include <machine/rtas.h>
46 #include <machine/stdarg.h>
47
48 #include <dev/ofw/openfirm.h>
49
50 static MALLOC_DEFINE(M_RTAS, "rtas", "Run Time Abstraction Service");
51
52 static vm_offset_t rtas_bounce_phys;
53 static caddr_t rtas_bounce_virt;
54 static off_t rtas_bounce_offset;
55 static size_t rtas_bounce_size;
56 static uintptr_t rtas_private_data;
57 static struct mtx rtas_mtx;
58 static phandle_t rtas;
59
60 /* From ofwcall.S */
61 int rtascall(vm_offset_t callbuffer, uintptr_t rtas_privdat);
62 extern uintptr_t rtas_entry;
63 extern register_t rtasmsr;
64
65 /*
66 * After the VM is up, allocate RTAS memory and instantiate it
67 */
68
69 static void rtas_setup(void *);
70
71 SYSINIT(rtas_setup, SI_SUB_KMEM, SI_ORDER_ANY, rtas_setup, NULL);
72
73 static void
rtas_setup(void * junk)74 rtas_setup(void *junk)
75 {
76 ihandle_t rtasi;
77 cell_t rtas_size = 0, rtas_ptr;
78 char path[31];
79 int result;
80
81 rtas = OF_finddevice("/rtas");
82 if (rtas == -1) {
83 rtas = 0;
84 return;
85 }
86 OF_package_to_path(rtas, path, sizeof(path));
87
88 mtx_init(&rtas_mtx, "RTAS", NULL, MTX_SPIN);
89
90 /* RTAS must be called with everything turned off in MSR */
91 rtasmsr = mfmsr();
92 rtasmsr &= ~(PSL_IR | PSL_DR | PSL_EE | PSL_SE | PSL_LE);
93 #ifdef __powerpc64__
94 rtasmsr &= ~PSL_SF;
95 #endif
96
97 /*
98 * Allocate rtas_size + one page of contiguous, wired physical memory
99 * that can fit into a 32-bit address space and accessed from real mode.
100 * This is used both to bounce arguments and for RTAS private data.
101 *
102 * It must be 4KB-aligned and not cross a 256 MB boundary.
103 */
104
105 OF_getencprop(rtas, "rtas-size", &rtas_size, sizeof(rtas_size));
106 rtas_size = round_page(rtas_size);
107 rtas_bounce_virt = contigmalloc(rtas_size + PAGE_SIZE, M_RTAS, 0, 0,
108 ulmin(platform_real_maxaddr(), BUS_SPACE_MAXADDR_32BIT),
109 4096, 256*1024*1024);
110
111 rtas_private_data = vtophys(rtas_bounce_virt);
112 rtas_bounce_virt += rtas_size; /* Actual bounce area */
113 rtas_bounce_phys = vtophys(rtas_bounce_virt);
114 rtas_bounce_size = PAGE_SIZE;
115
116 /*
117 * Instantiate RTAS. We always use the 32-bit version.
118 */
119
120 if (OF_hasprop(rtas, "linux,rtas-entry") &&
121 OF_hasprop(rtas, "linux,rtas-base")) {
122 OF_getencprop(rtas, "linux,rtas-base", &rtas_ptr,
123 sizeof(rtas_ptr));
124 rtas_private_data = rtas_ptr;
125 OF_getencprop(rtas, "linux,rtas-entry", &rtas_ptr,
126 sizeof(rtas_ptr));
127 } else {
128 rtasi = OF_open(path);
129 if (rtasi == 0) {
130 rtas = 0;
131 printf("Error initializing RTAS: could not open "
132 "node\n");
133 return;
134 }
135
136 result = OF_call_method("instantiate-rtas", rtasi, 1, 1,
137 (cell_t)rtas_private_data, &rtas_ptr);
138 OF_close(rtasi);
139
140 if (result != 0) {
141 rtas = 0;
142 rtas_ptr = 0;
143 printf("Error initializing RTAS (%d)\n", result);
144 return;
145 }
146 }
147
148 rtas_entry = (uintptr_t)(rtas_ptr);
149 }
150
151 static cell_t
rtas_real_map(const void * buf,size_t len)152 rtas_real_map(const void *buf, size_t len)
153 {
154 cell_t phys;
155
156 mtx_assert(&rtas_mtx, MA_OWNED);
157
158 /*
159 * Make sure the bounce page offset satisfies any reasonable
160 * alignment constraint.
161 */
162 rtas_bounce_offset += sizeof(register_t) -
163 (rtas_bounce_offset % sizeof(register_t));
164
165 if (rtas_bounce_offset + len > rtas_bounce_size) {
166 panic("Oversize RTAS call!");
167 return 0;
168 }
169
170 if (buf != NULL)
171 memcpy(rtas_bounce_virt + rtas_bounce_offset, buf, len);
172 else
173 return (0);
174
175 phys = rtas_bounce_phys + rtas_bounce_offset;
176 rtas_bounce_offset += len;
177
178 return (phys);
179 }
180
181 static void
rtas_real_unmap(cell_t physaddr,void * buf,size_t len)182 rtas_real_unmap(cell_t physaddr, void *buf, size_t len)
183 {
184 mtx_assert(&rtas_mtx, MA_OWNED);
185
186 if (physaddr == 0)
187 return;
188
189 memcpy(buf, rtas_bounce_virt + (physaddr - rtas_bounce_phys), len);
190 }
191
192 /* Check if we have RTAS */
193 int
rtas_exists(void)194 rtas_exists(void)
195 {
196 return (rtas != 0);
197 }
198
199 /* Call an RTAS method by token */
200 int
rtas_call_method(cell_t token,int nargs,int nreturns,...)201 rtas_call_method(cell_t token, int nargs, int nreturns, ...)
202 {
203 vm_offset_t argsptr;
204 jmp_buf env, *oldfaultbuf;
205 va_list ap;
206 struct {
207 cell_t token;
208 cell_t nargs;
209 cell_t nreturns;
210 cell_t args_n_results[12];
211 } args;
212 int n, result;
213
214 if (!rtas_exists() || nargs + nreturns > 12)
215 return (-1);
216
217 args.token = htobe32(token);
218 va_start(ap, nreturns);
219
220 mtx_lock_spin(&rtas_mtx);
221 rtas_bounce_offset = 0;
222
223 args.nargs = htobe32(nargs);
224 args.nreturns = htobe32(nreturns);
225
226 for (n = 0; n < nargs; n++)
227 args.args_n_results[n] = htobe32(va_arg(ap, cell_t));
228
229 argsptr = rtas_real_map(&args, sizeof(args));
230
231 /* Get rid of any stale machine checks that have been waiting. */
232 __asm __volatile ("sync; isync");
233 oldfaultbuf = curthread->td_pcb->pcb_onfault;
234 curthread->td_pcb->pcb_onfault = &env;
235 if (!setjmp(env)) {
236 __asm __volatile ("sync");
237 result = rtascall(argsptr, rtas_private_data);
238 __asm __volatile ("sync; isync");
239 } else {
240 result = RTAS_HW_ERROR;
241 }
242 curthread->td_pcb->pcb_onfault = oldfaultbuf;
243 __asm __volatile ("sync");
244
245 rtas_real_unmap(argsptr, &args, sizeof(args));
246 mtx_unlock_spin(&rtas_mtx);
247
248 if (result < 0)
249 return (result);
250
251 for (n = nargs; n < nargs + nreturns; n++)
252 *va_arg(ap, cell_t *) = be32toh(args.args_n_results[n]);
253 return (result);
254 }
255
256 /* Look up an RTAS token */
257 cell_t
rtas_token_lookup(const char * method)258 rtas_token_lookup(const char *method)
259 {
260 cell_t token;
261
262 if (!rtas_exists())
263 return (-1);
264
265 if (OF_getencprop(rtas, method, &token, sizeof(token)) == -1)
266 return (-1);
267
268 return (token);
269 }
270