xref: /freebsd/sys/powerpc/ofw/rtas.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
1 /*-
2  * Copyright (c) 2011 Nathan Whitehorn
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("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/lock.h>
33 #include <sys/mutex.h>
34 #include <sys/systm.h>
35 
36 #include <vm/vm.h>
37 #include <vm/vm_page.h>
38 #include <vm/pmap.h>
39 
40 #include <machine/bus.h>
41 #include <machine/md_var.h>
42 #include <machine/pmap.h>
43 #include <machine/rtas.h>
44 #include <machine/stdarg.h>
45 
46 #include <dev/ofw/openfirm.h>
47 
48 MALLOC_DEFINE(M_RTAS, "rtas", "Run Time Abstraction Service");
49 
50 static vm_offset_t	rtas_bounce_phys;
51 static caddr_t		rtas_bounce_virt;
52 static off_t		rtas_bounce_offset;
53 static size_t		rtas_bounce_size;
54 static uintptr_t	rtas_private_data;
55 static struct mtx	rtas_mtx;
56 static phandle_t	rtas;
57 
58 /* From ofwcall.S */
59 int rtascall(vm_offset_t callbuffer, uintptr_t rtas_privdat);
60 extern uintptr_t	rtas_entry;
61 extern register_t	rtasmsr;
62 
63 /*
64  * After the VM is up, allocate RTAS memory and instantiate it
65  */
66 
67 static void rtas_setup(void *);
68 
69 SYSINIT(rtas_setup, SI_SUB_KMEM, SI_ORDER_ANY, rtas_setup, NULL);
70 
71 static void
72 rtas_setup(void *junk)
73 {
74 	ihandle_t rtasi;
75 	cell_t rtas_size = 0, rtas_ptr;
76 	char path[31];
77 	int result;
78 
79 	rtas = OF_finddevice("/rtas");
80 	if (rtas == -1) {
81 		rtas = 0;
82 		return;
83 	}
84 	OF_package_to_path(rtas, path, sizeof(path));
85 	rtasi = OF_open(path);
86 	if (rtasi == 0) {
87 		rtas = 0;
88 		printf("Error initializing RTAS: could not open node\n");
89 		return;
90 	}
91 
92 	mtx_init(&rtas_mtx, "RTAS", MTX_DEF, 0);
93 
94 	/* RTAS must be called with everything turned off in MSR */
95 	rtasmsr = mfmsr();
96 	rtasmsr &= ~(PSL_IR | PSL_DR | PSL_EE | PSL_SE);
97 	#ifdef __powerpc64__
98 	rtasmsr &= ~PSL_SF;
99 	#endif
100 
101 	/*
102 	 * Allocate rtas_size + one page of contiguous, wired physical memory
103 	 * that can fit into a 32-bit address space and accessed from real mode.
104 	 * This is used both to bounce arguments and for RTAS private data.
105 	 *
106 	 * It must be 4KB-aligned and not cross a 256 MB boundary.
107 	 */
108 
109 	OF_getprop(rtas, "rtas-size", &rtas_size, sizeof(rtas_size));
110 	rtas_size = round_page(rtas_size);
111 	rtas_bounce_virt = contigmalloc(rtas_size + PAGE_SIZE, M_RTAS, 0, 0,
112 	    ulmin(platform_real_maxaddr(), BUS_SPACE_MAXADDR_32BIT),
113 	    4096, 256*1024*1024);
114 
115 	rtas_private_data = vtophys(rtas_bounce_virt);
116 	rtas_bounce_virt += rtas_size;	/* Actual bounce area */
117 	rtas_bounce_phys = vtophys(rtas_bounce_virt);
118 	rtas_bounce_size = PAGE_SIZE;
119 
120 	/*
121 	 * Instantiate RTAS. We always use the 32-bit version.
122 	 */
123 
124 	result = OF_call_method("instantiate-rtas", rtasi, 1, 1,
125 	    (cell_t)rtas_private_data, &rtas_ptr);
126 	OF_close(rtasi);
127 
128 	if (result != 0) {
129 		rtas = 0;
130 		rtas_ptr = 0;
131 		printf("Error initializing RTAS (%d)\n", result);
132 		return;
133 	}
134 
135 	rtas_entry = (uintptr_t)(rtas_ptr);
136 }
137 
138 static cell_t
139 rtas_real_map(const void *buf, size_t len)
140 {
141 	cell_t phys;
142 
143 	mtx_assert(&rtas_mtx, MA_OWNED);
144 
145 	/*
146 	 * Make sure the bounce page offset satisfies any reasonable
147 	 * alignment constraint.
148 	 */
149 	rtas_bounce_offset += sizeof(register_t) -
150 	    (rtas_bounce_offset % sizeof(register_t));
151 
152 	if (rtas_bounce_offset + len > rtas_bounce_size) {
153 		panic("Oversize RTAS call!");
154 		return 0;
155 	}
156 
157 	if (buf != NULL)
158 		memcpy(rtas_bounce_virt + rtas_bounce_offset, buf, len);
159 	else
160 		return (0);
161 
162 	phys = rtas_bounce_phys + rtas_bounce_offset;
163 	rtas_bounce_offset += len;
164 
165 	return (phys);
166 }
167 
168 static void
169 rtas_real_unmap(cell_t physaddr, void *buf, size_t len)
170 {
171 	mtx_assert(&rtas_mtx, MA_OWNED);
172 
173 	if (physaddr == 0)
174 		return;
175 
176 	memcpy(buf, rtas_bounce_virt + (physaddr - rtas_bounce_phys), len);
177 }
178 
179 /* Check if we have RTAS */
180 int
181 rtas_exists(void)
182 {
183 	return (rtas != 0);
184 }
185 
186 /* Call an RTAS method by token */
187 int
188 rtas_call_method(cell_t token, int nargs, int nreturns, ...)
189 {
190 	vm_offset_t argsptr;
191 	va_list ap;
192 	struct {
193 		cell_t token;
194 		cell_t nargs;
195 		cell_t nreturns;
196 		cell_t args_n_results[12];
197 	} args;
198 	int n, result;
199 
200 	if (!rtas_exists() || nargs + nreturns > 12)
201 		return (-1);
202 
203 	args.token = token;
204 	va_start(ap, nreturns);
205 
206 	mtx_lock(&rtas_mtx);
207 	rtas_bounce_offset = 0;
208 
209 	args.nargs = nargs;
210 	args.nreturns = nreturns;
211 
212 	for (n = 0; n < nargs; n++)
213 		args.args_n_results[n] = va_arg(ap, cell_t);
214 
215 	argsptr = rtas_real_map(&args, sizeof(args));
216 	result = rtascall(argsptr, rtas_private_data);
217 	rtas_real_unmap(argsptr, &args, sizeof(args));
218 	mtx_unlock(&rtas_mtx);
219 
220 	if (result < 0)
221 		return (result);
222 
223 	for (n = nargs; n < nargs + nreturns; n++)
224 		*va_arg(ap, cell_t *) = args.args_n_results[n];
225 	return (result);
226 }
227 
228 /* Look up an RTAS token */
229 cell_t
230 rtas_token_lookup(const char *method)
231 {
232 	cell_t token;
233 
234 	if (!rtas_exists())
235 		return (-1);
236 
237 	if (OF_getprop(rtas, method, &token, sizeof(token)) == -1)
238 		return (-1);
239 
240 	return (token);
241 }
242 
243 
244