rtas.c revision 222613
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: head/sys/powerpc/ofw/rtas.c 222613 2011-06-02 14:12:37Z nwhitehorn $"); 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 48MALLOC_DEFINE(M_RTAS, "rtas", "Run Time Abstraction Service"); 49 50static vm_offset_t rtas_bounce_phys; 51static caddr_t rtas_bounce_virt; 52static off_t rtas_bounce_offset; 53static size_t rtas_bounce_size; 54static uintptr_t rtas_private_data; 55static struct mtx rtas_mtx; 56static phandle_t rtas; 57 58/* From ofwcall.S */ 59int rtascall(vm_offset_t callbuffer, uintptr_t rtas_privdat); 60extern uintptr_t rtas_entry; 61extern register_t rtasmsr; 62 63/* 64 * After the VM is up, allocate RTAS memory and instantiate it 65 */ 66 67static void rtas_setup(void *); 68 69SYSINIT(rtas_setup, SI_SUB_KMEM, SI_ORDER_ANY, rtas_setup, NULL); 70 71static void 72rtas_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 138static cell_t 139rtas_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 168static void 169rtas_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 */ 180int 181rtas_exists(void) 182{ 183 return (rtas != 0); 184} 185 186/* Call an RTAS method by token */ 187int 188rtas_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 */ 229cell_t 230rtas_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