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 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 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 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 195 rtas_exists(void) 196 { 197 return (rtas != 0); 198 } 199 200 /* Call an RTAS method by token */ 201 int 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 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