1 /* $NetBSD: fdt_intr.c,v 1.17 2018/07/15 16:59:16 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 1.17 2018/07/15 16:59:16 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 struct fdtbus_interrupt_controller *ic; 138 struct fdtbus_interrupt_cookie *c = NULL; 139 const u_int *specifier; 140 int ihandle; 141 void *ih; 142 143 specifier = get_specifier_by_index(phandle, index, &ihandle); 144 if (specifier == NULL) 145 return NULL; 146 147 ic = fdtbus_get_interrupt_controller(ihandle); 148 if (ic == NULL) 149 return NULL; 150 151 ih = ic->ic_funcs->establish(ic->ic_dev, __UNCONST(specifier), 152 ipl, flags, func, arg); 153 if (ih != NULL) { 154 c = kmem_alloc(sizeof(*c), KM_SLEEP); 155 c->c_ic = ic; 156 c->c_ih = ih; 157 LIST_INSERT_HEAD(&fdtbus_interrupt_cookies, c, c_next); 158 } 159 160 return ih; 161 } 162 163 void 164 fdtbus_intr_disestablish(int phandle, void *cookie) 165 { 166 struct fdtbus_interrupt_controller *ic = NULL; 167 struct fdtbus_interrupt_cookie *c; 168 169 LIST_FOREACH(c, &fdtbus_interrupt_cookies, c_next) { 170 if (c->c_ih == cookie) { 171 ic = c->c_ic; 172 LIST_REMOVE(c, c_next); 173 kmem_free(c, sizeof(*c)); 174 break; 175 } 176 } 177 178 if (ic != NULL) 179 panic("%s: interrupt handle not valid", __func__); 180 181 return ic->ic_funcs->disestablish(ic->ic_dev, cookie); 182 } 183 184 bool 185 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen) 186 { 187 struct fdtbus_interrupt_controller *ic; 188 const u_int *specifier; 189 int ihandle; 190 191 specifier = get_specifier_by_index(phandle, index, &ihandle); 192 193 ic = fdtbus_get_interrupt_controller(ihandle); 194 if (ic == NULL) 195 return false; 196 197 return ic->ic_funcs->intrstr(ic->ic_dev, __UNCONST(specifier), buf, buflen); 198 } 199 200 static int 201 find_address_cells(int phandle) 202 { 203 uint32_t cells; 204 205 if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0) 206 cells = 2; 207 208 return cells; 209 } 210 211 static int 212 find_interrupt_cells(int phandle) 213 { 214 uint32_t cells; 215 216 while (phandle > 0) { 217 if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0) 218 return cells; 219 phandle = OF_parent(phandle); 220 } 221 return 0; 222 } 223 224 static const u_int * 225 get_specifier_from_map(int phandle, const u_int *interrupt_spec, int *piphandle) 226 { 227 const u_int *result = NULL; 228 int len, resid; 229 230 const u_int *data = fdtbus_get_prop(phandle, "interrupt-map", &len); 231 if (data == NULL || len <= 0) 232 return NULL; 233 resid = len; 234 235 /* child unit address: #address-cells prop of child bus node */ 236 const int cua_cells = find_address_cells(phandle); 237 /* child interrupt specifier: #interrupt-cells of the nexus node */ 238 const int cis_cells = find_interrupt_cells(phandle); 239 240 /* Offset (in cells) from map entry to child unit address specifier */ 241 const u_int cua_off = 0; 242 /* Offset (in cells) from map entry to child interrupt specifier */ 243 const u_int cis_off = cua_off + cua_cells; 244 /* Offset (in cells) from map entry to interrupt parent phandle */ 245 const u_int ip_off = cis_off + cis_cells; 246 /* Offset (in cells) from map entry to parent unit specifier */ 247 const u_int pus_off = ip_off + 1; 248 249 const u_int *p = (const u_int *)data; 250 while (resid > 0) { 251 /* Interrupt parent phandle */ 252 const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off])); 253 254 /* parent unit specifier: #address-cells of the interrupt parent */ 255 const u_int pus_cells = find_address_cells(iparent); 256 /* parent interrupt specifier: #interrupt-cells of the interrupt parent */ 257 const u_int pis_cells = find_interrupt_cells(iparent); 258 259 /* Offset (in cells) from map entry to parent interrupt specifier */ 260 const u_int pis_off = pus_off + pus_cells; 261 262 #ifdef FDT_INTR_DEBUG 263 printf(" intr map (len %d):", pis_off + pis_cells); 264 for (int i = 0; i < pis_off + pis_cells; i++) 265 printf(" %08x", p[i]); 266 printf("\n"); 267 #endif 268 269 if (memcmp(&p[cis_off], interrupt_spec, cis_cells * 4) == 0) { 270 #ifdef FDT_INTR_DEBUG 271 const int slen = pus_cells + pis_cells; 272 printf(" intr map match iparent %08x slen %d:", iparent, slen); 273 for (int i = 0; i < slen; i++) 274 printf(" %08x", p[pus_off + i]); 275 printf("\n"); 276 #endif 277 result = &p[pus_off]; 278 *piphandle = iparent; 279 goto done; 280 } 281 /* Determine the length of the entry and skip that many 282 * 32 bit words 283 */ 284 const u_int reclen = pis_off + pis_cells; 285 resid -= reclen * sizeof(u_int); 286 p += reclen; 287 } 288 289 done: 290 return result; 291 } 292 293 static const u_int * 294 get_specifier_by_index(int phandle, int pindex, int *piphandle) 295 { 296 const u_int *node_specifier; 297 int interrupt_parent, interrupt_cells, len; 298 299 interrupt_parent = fdtbus_get_interrupt_parent(phandle); 300 if (interrupt_parent <= 0) 301 return NULL; 302 303 node_specifier = fdtbus_get_prop(phandle, "interrupts", &len); 304 if (node_specifier == NULL) 305 return NULL; 306 307 interrupt_cells = find_interrupt_cells(interrupt_parent); 308 if (interrupt_cells <= 0) 309 return NULL; 310 311 const u_int spec_length = len / 4; 312 const u_int nintr = spec_length / interrupt_cells; 313 if (pindex >= nintr) 314 return NULL; 315 316 node_specifier += (interrupt_cells * pindex); 317 318 if (of_hasprop(interrupt_parent, "interrupt-map")) 319 return get_specifier_from_map(interrupt_parent, node_specifier, piphandle); 320 321 *piphandle = interrupt_parent; 322 323 return node_specifier; 324 } 325