1 /* $NetBSD: fdt_intr.c,v 1.18 2018/09/06 22:54:05 jmcneill Exp $ */ 2 3 /*- 4 * Copyright (c) 2015-2018 Jared McNeill <jmcneill@invisible.ca> 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 ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * 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 __KERNEL_RCSID(0, "$NetBSD: fdt_intr.c,v 1.18 2018/09/06 22:54:05 jmcneill Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/kmem.h> 35 #include <sys/queue.h> 36 37 #include <libfdt.h> 38 #include <dev/fdt/fdtvar.h> 39 40 struct fdtbus_interrupt_controller { 41 device_t ic_dev; 42 int ic_phandle; 43 const struct fdtbus_interrupt_controller_func *ic_funcs; 44 45 LIST_ENTRY(fdtbus_interrupt_controller) ic_next; 46 }; 47 48 static LIST_HEAD(, fdtbus_interrupt_controller) fdtbus_interrupt_controllers = 49 LIST_HEAD_INITIALIZER(fdtbus_interrupt_controllers); 50 51 struct fdtbus_interrupt_cookie { 52 struct fdtbus_interrupt_controller *c_ic; 53 void *c_ih; 54 55 LIST_ENTRY(fdtbus_interrupt_cookie) c_next; 56 }; 57 58 static LIST_HEAD(, fdtbus_interrupt_cookie) fdtbus_interrupt_cookies = 59 LIST_HEAD_INITIALIZER(fdtbus_interrupt_cookies); 60 61 static const u_int * get_specifier_by_index(int, int, int *); 62 static const u_int * get_specifier_from_map(int, const u_int *, int *); 63 64 /* 65 * Find the interrupt controller for a given node. This function will either 66 * return the phandle of the interrupt controller for this node, or the phandle 67 * of a node containing an interrupt-map table that can be used to find the 68 * real interrupt controller. 69 */ 70 static int 71 fdtbus_get_interrupt_parent(int phandle) 72 { 73 int iparent = phandle; 74 75 do { 76 /* 77 * If the node is an interrupt-controller, we are done. Note that 78 * a node cannot be an interrupt-controller for itself, so we skip 79 * the leaf node here. 80 */ 81 if (phandle != iparent && of_hasprop(iparent, "interrupt-controller")) 82 return iparent; 83 84 /* 85 * If the node has an explicit interrupt-parent, follow the reference. 86 */ 87 if (of_hasprop(iparent, "interrupt-parent")) 88 return fdtbus_get_phandle(iparent, "interrupt-parent"); 89 90 /* 91 * If the node has an interrupt-map, use it. The caller is responsible 92 * for parsing the interrupt-map and finding the real interrupt parent. 93 */ 94 if (of_hasprop(iparent, "interrupt-map")) 95 return iparent; 96 97 /* 98 * Continue searching up the tree. 99 */ 100 iparent = OF_parent(iparent); 101 } while (iparent > 0); 102 103 return 0; 104 } 105 106 static struct fdtbus_interrupt_controller * 107 fdtbus_get_interrupt_controller(int phandle) 108 { 109 struct fdtbus_interrupt_controller * ic; 110 LIST_FOREACH(ic, &fdtbus_interrupt_controllers, ic_next) { 111 if (ic->ic_phandle == phandle) 112 return ic; 113 } 114 return NULL; 115 } 116 117 int 118 fdtbus_register_interrupt_controller(device_t dev, int phandle, 119 const struct fdtbus_interrupt_controller_func *funcs) 120 { 121 struct fdtbus_interrupt_controller *ic; 122 123 ic = kmem_alloc(sizeof(*ic), KM_SLEEP); 124 ic->ic_dev = dev; 125 ic->ic_phandle = phandle; 126 ic->ic_funcs = funcs; 127 128 LIST_INSERT_HEAD(&fdtbus_interrupt_controllers, ic, ic_next); 129 130 return 0; 131 } 132 133 void * 134 fdtbus_intr_establish(int phandle, u_int index, int ipl, int flags, 135 int (*func)(void *), void *arg) 136 { 137 const u_int *specifier; 138 int ihandle; 139 140 specifier = get_specifier_by_index(phandle, index, &ihandle); 141 if (specifier == NULL) 142 return NULL; 143 144 return fdtbus_intr_establish_raw(ihandle, specifier, ipl, 145 flags, func, arg); 146 } 147 148 void * 149 fdtbus_intr_establish_raw(int ihandle, const u_int *specifier, int ipl, 150 int flags, int (*func)(void *), void *arg) 151 { 152 struct fdtbus_interrupt_controller *ic; 153 struct fdtbus_interrupt_cookie *c; 154 void *ih; 155 156 ic = fdtbus_get_interrupt_controller(ihandle); 157 if (ic == NULL) 158 return NULL; 159 160 ih = ic->ic_funcs->establish(ic->ic_dev, __UNCONST(specifier), 161 ipl, flags, func, arg); 162 if (ih != NULL) { 163 c = kmem_alloc(sizeof(*c), KM_SLEEP); 164 c->c_ic = ic; 165 c->c_ih = ih; 166 LIST_INSERT_HEAD(&fdtbus_interrupt_cookies, c, c_next); 167 } 168 169 return ih; 170 } 171 172 void 173 fdtbus_intr_disestablish(int phandle, void *cookie) 174 { 175 struct fdtbus_interrupt_controller *ic = NULL; 176 struct fdtbus_interrupt_cookie *c; 177 178 LIST_FOREACH(c, &fdtbus_interrupt_cookies, c_next) { 179 if (c->c_ih == cookie) { 180 ic = c->c_ic; 181 LIST_REMOVE(c, c_next); 182 kmem_free(c, sizeof(*c)); 183 break; 184 } 185 } 186 187 if (ic != NULL) 188 panic("%s: interrupt handle not valid", __func__); 189 190 return ic->ic_funcs->disestablish(ic->ic_dev, cookie); 191 } 192 193 bool 194 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen) 195 { 196 const u_int *specifier; 197 int ihandle; 198 199 specifier = get_specifier_by_index(phandle, index, &ihandle); 200 if (specifier == NULL) 201 return false; 202 203 return fdtbus_intr_str_raw(ihandle, specifier, buf, buflen); 204 } 205 206 bool 207 fdtbus_intr_str_raw(int ihandle, const u_int *specifier, char *buf, size_t buflen) 208 { 209 struct fdtbus_interrupt_controller *ic; 210 211 ic = fdtbus_get_interrupt_controller(ihandle); 212 if (ic == NULL) 213 return false; 214 215 return ic->ic_funcs->intrstr(ic->ic_dev, __UNCONST(specifier), buf, buflen); 216 } 217 218 static int 219 find_address_cells(int phandle) 220 { 221 uint32_t cells; 222 223 if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0) 224 cells = 2; 225 226 return cells; 227 } 228 229 static int 230 find_interrupt_cells(int phandle) 231 { 232 uint32_t cells; 233 234 while (phandle > 0) { 235 if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0) 236 return cells; 237 phandle = OF_parent(phandle); 238 } 239 return 0; 240 } 241 242 static const u_int * 243 get_specifier_from_map(int phandle, const u_int *interrupt_spec, int *piphandle) 244 { 245 const u_int *result = NULL; 246 int len, resid; 247 248 const u_int *data = fdtbus_get_prop(phandle, "interrupt-map", &len); 249 if (data == NULL || len <= 0) 250 return NULL; 251 resid = len; 252 253 /* child unit address: #address-cells prop of child bus node */ 254 const int cua_cells = find_address_cells(phandle); 255 /* child interrupt specifier: #interrupt-cells of the nexus node */ 256 const int cis_cells = find_interrupt_cells(phandle); 257 258 /* Offset (in cells) from map entry to child unit address specifier */ 259 const u_int cua_off = 0; 260 /* Offset (in cells) from map entry to child interrupt specifier */ 261 const u_int cis_off = cua_off + cua_cells; 262 /* Offset (in cells) from map entry to interrupt parent phandle */ 263 const u_int ip_off = cis_off + cis_cells; 264 /* Offset (in cells) from map entry to parent unit specifier */ 265 const u_int pus_off = ip_off + 1; 266 267 const u_int *p = (const u_int *)data; 268 while (resid > 0) { 269 /* Interrupt parent phandle */ 270 const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off])); 271 272 /* parent unit specifier: #address-cells of the interrupt parent */ 273 const u_int pus_cells = find_address_cells(iparent); 274 /* parent interrupt specifier: #interrupt-cells of the interrupt parent */ 275 const u_int pis_cells = find_interrupt_cells(iparent); 276 277 /* Offset (in cells) from map entry to parent interrupt specifier */ 278 const u_int pis_off = pus_off + pus_cells; 279 280 #ifdef FDT_INTR_DEBUG 281 printf(" intr map (len %d):", pis_off + pis_cells); 282 for (int i = 0; i < pis_off + pis_cells; i++) 283 printf(" %08x", p[i]); 284 printf("\n"); 285 #endif 286 287 if (memcmp(&p[cis_off], interrupt_spec, cis_cells * 4) == 0) { 288 #ifdef FDT_INTR_DEBUG 289 const int slen = pus_cells + pis_cells; 290 printf(" intr map match iparent %08x slen %d:", iparent, slen); 291 for (int i = 0; i < slen; i++) 292 printf(" %08x", p[pus_off + i]); 293 printf("\n"); 294 #endif 295 result = &p[pus_off]; 296 *piphandle = iparent; 297 goto done; 298 } 299 /* Determine the length of the entry and skip that many 300 * 32 bit words 301 */ 302 const u_int reclen = pis_off + pis_cells; 303 resid -= reclen * sizeof(u_int); 304 p += reclen; 305 } 306 307 done: 308 return result; 309 } 310 311 static const u_int * 312 get_specifier_by_index(int phandle, int pindex, int *piphandle) 313 { 314 const u_int *node_specifier; 315 int interrupt_parent, interrupt_cells, len; 316 317 interrupt_parent = fdtbus_get_interrupt_parent(phandle); 318 if (interrupt_parent <= 0) 319 return NULL; 320 321 node_specifier = fdtbus_get_prop(phandle, "interrupts", &len); 322 if (node_specifier == NULL) 323 return NULL; 324 325 interrupt_cells = find_interrupt_cells(interrupt_parent); 326 if (interrupt_cells <= 0) 327 return NULL; 328 329 const u_int spec_length = len / 4; 330 const u_int nintr = spec_length / interrupt_cells; 331 if (pindex >= nintr) 332 return NULL; 333 334 node_specifier += (interrupt_cells * pindex); 335 336 if (of_hasprop(interrupt_parent, "interrupt-map")) 337 return get_specifier_from_map(interrupt_parent, node_specifier, piphandle); 338 339 *piphandle = interrupt_parent; 340 341 return node_specifier; 342 } 343