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