1 /* 2 * Copyright 2011 IBM Corporation. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 */ 10 11 #include <linux/types.h> 12 #include <linux/kernel.h> 13 #include <linux/irq.h> 14 #include <linux/smp.h> 15 #include <linux/interrupt.h> 16 #include <linux/init.h> 17 #include <linux/cpu.h> 18 #include <linux/of.h> 19 #include <linux/spinlock.h> 20 #include <linux/module.h> 21 22 #include <asm/prom.h> 23 #include <asm/io.h> 24 #include <asm/smp.h> 25 #include <asm/irq.h> 26 #include <asm/errno.h> 27 #include <asm/xics.h> 28 #include <asm/kvm_ppc.h> 29 #include <asm/dbell.h> 30 31 struct icp_ipl { 32 union { 33 u32 word; 34 u8 bytes[4]; 35 } xirr_poll; 36 union { 37 u32 word; 38 u8 bytes[4]; 39 } xirr; 40 u32 dummy; 41 union { 42 u32 word; 43 u8 bytes[4]; 44 } qirr; 45 u32 link_a; 46 u32 link_b; 47 u32 link_c; 48 }; 49 50 static struct icp_ipl __iomem *icp_native_regs[NR_CPUS]; 51 52 static inline unsigned int icp_native_get_xirr(void) 53 { 54 int cpu = smp_processor_id(); 55 unsigned int xirr; 56 57 /* Handled an interrupt latched by KVM */ 58 xirr = kvmppc_get_xics_latch(); 59 if (xirr) 60 return xirr; 61 62 return in_be32(&icp_native_regs[cpu]->xirr.word); 63 } 64 65 static inline void icp_native_set_xirr(unsigned int value) 66 { 67 int cpu = smp_processor_id(); 68 69 out_be32(&icp_native_regs[cpu]->xirr.word, value); 70 } 71 72 static inline void icp_native_set_cppr(u8 value) 73 { 74 int cpu = smp_processor_id(); 75 76 out_8(&icp_native_regs[cpu]->xirr.bytes[0], value); 77 } 78 79 static inline void icp_native_set_qirr(int n_cpu, u8 value) 80 { 81 out_8(&icp_native_regs[n_cpu]->qirr.bytes[0], value); 82 } 83 84 static void icp_native_set_cpu_priority(unsigned char cppr) 85 { 86 xics_set_base_cppr(cppr); 87 icp_native_set_cppr(cppr); 88 iosync(); 89 } 90 91 void icp_native_eoi(struct irq_data *d) 92 { 93 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 94 95 iosync(); 96 icp_native_set_xirr((xics_pop_cppr() << 24) | hw_irq); 97 } 98 99 static void icp_native_teardown_cpu(void) 100 { 101 int cpu = smp_processor_id(); 102 103 /* Clear any pending IPI */ 104 icp_native_set_qirr(cpu, 0xff); 105 } 106 107 static void icp_native_flush_ipi(void) 108 { 109 /* We take the ipi irq but and never return so we 110 * need to EOI the IPI, but want to leave our priority 0 111 * 112 * should we check all the other interrupts too? 113 * should we be flagging idle loop instead? 114 * or creating some task to be scheduled? 115 */ 116 117 icp_native_set_xirr((0x00 << 24) | XICS_IPI); 118 } 119 120 static unsigned int icp_native_get_irq(void) 121 { 122 unsigned int xirr = icp_native_get_xirr(); 123 unsigned int vec = xirr & 0x00ffffff; 124 unsigned int irq; 125 126 if (vec == XICS_IRQ_SPURIOUS) 127 return NO_IRQ; 128 129 irq = irq_find_mapping(xics_host, vec); 130 if (likely(irq != NO_IRQ)) { 131 xics_push_cppr(vec); 132 return irq; 133 } 134 135 /* We don't have a linux mapping, so have rtas mask it. */ 136 xics_mask_unknown_vec(vec); 137 138 /* We might learn about it later, so EOI it */ 139 icp_native_set_xirr(xirr); 140 141 return NO_IRQ; 142 } 143 144 #ifdef CONFIG_SMP 145 146 static void icp_native_cause_ipi(int cpu, unsigned long data) 147 { 148 kvmppc_set_host_ipi(cpu, 1); 149 #ifdef CONFIG_PPC_DOORBELL 150 if (cpu_has_feature(CPU_FTR_DBELL)) { 151 if (cpumask_test_cpu(cpu, cpu_sibling_mask(get_cpu()))) { 152 doorbell_cause_ipi(cpu, data); 153 put_cpu(); 154 return; 155 } 156 put_cpu(); 157 } 158 #endif 159 icp_native_set_qirr(cpu, IPI_PRIORITY); 160 } 161 162 /* 163 * Called when an interrupt is received on an off-line CPU to 164 * clear the interrupt, so that the CPU can go back to nap mode. 165 */ 166 void icp_native_flush_interrupt(void) 167 { 168 unsigned int xirr = icp_native_get_xirr(); 169 unsigned int vec = xirr & 0x00ffffff; 170 171 if (vec == XICS_IRQ_SPURIOUS) 172 return; 173 if (vec == XICS_IPI) { 174 /* Clear pending IPI */ 175 int cpu = smp_processor_id(); 176 kvmppc_set_host_ipi(cpu, 0); 177 icp_native_set_qirr(cpu, 0xff); 178 } else { 179 pr_err("XICS: hw interrupt 0x%x to offline cpu, disabling\n", 180 vec); 181 xics_mask_unknown_vec(vec); 182 } 183 /* EOI the interrupt */ 184 icp_native_set_xirr(xirr); 185 } 186 187 void xics_wake_cpu(int cpu) 188 { 189 icp_native_set_qirr(cpu, IPI_PRIORITY); 190 } 191 EXPORT_SYMBOL_GPL(xics_wake_cpu); 192 193 static irqreturn_t icp_native_ipi_action(int irq, void *dev_id) 194 { 195 int cpu = smp_processor_id(); 196 197 kvmppc_set_host_ipi(cpu, 0); 198 icp_native_set_qirr(cpu, 0xff); 199 200 return smp_ipi_demux(); 201 } 202 203 #endif /* CONFIG_SMP */ 204 205 static int __init icp_native_map_one_cpu(int hw_id, unsigned long addr, 206 unsigned long size) 207 { 208 char *rname; 209 int i, cpu = -1; 210 211 /* This may look gross but it's good enough for now, we don't quite 212 * have a hard -> linux processor id matching. 213 */ 214 for_each_possible_cpu(i) { 215 if (!cpu_present(i)) 216 continue; 217 if (hw_id == get_hard_smp_processor_id(i)) { 218 cpu = i; 219 break; 220 } 221 } 222 223 /* Fail, skip that CPU. Don't print, it's normal, some XICS come up 224 * with way more entries in there than you have CPUs 225 */ 226 if (cpu == -1) 227 return 0; 228 229 rname = kasprintf(GFP_KERNEL, "CPU %d [0x%x] Interrupt Presentation", 230 cpu, hw_id); 231 232 if (!request_mem_region(addr, size, rname)) { 233 pr_warning("icp_native: Could not reserve ICP MMIO" 234 " for CPU %d, interrupt server #0x%x\n", 235 cpu, hw_id); 236 return -EBUSY; 237 } 238 239 icp_native_regs[cpu] = ioremap(addr, size); 240 kvmppc_set_xics_phys(cpu, addr); 241 if (!icp_native_regs[cpu]) { 242 pr_warning("icp_native: Failed ioremap for CPU %d, " 243 "interrupt server #0x%x, addr %#lx\n", 244 cpu, hw_id, addr); 245 release_mem_region(addr, size); 246 return -ENOMEM; 247 } 248 return 0; 249 } 250 251 static int __init icp_native_init_one_node(struct device_node *np, 252 unsigned int *indx) 253 { 254 unsigned int ilen; 255 const __be32 *ireg; 256 int i; 257 int reg_tuple_size; 258 int num_servers = 0; 259 260 /* This code does the theorically broken assumption that the interrupt 261 * server numbers are the same as the hard CPU numbers. 262 * This happens to be the case so far but we are playing with fire... 263 * should be fixed one of these days. -BenH. 264 */ 265 ireg = of_get_property(np, "ibm,interrupt-server-ranges", &ilen); 266 267 /* Do that ever happen ? we'll know soon enough... but even good'old 268 * f80 does have that property .. 269 */ 270 WARN_ON((ireg == NULL) || (ilen != 2*sizeof(u32))); 271 272 if (ireg) { 273 *indx = of_read_number(ireg, 1); 274 if (ilen >= 2*sizeof(u32)) 275 num_servers = of_read_number(ireg + 1, 1); 276 } 277 278 ireg = of_get_property(np, "reg", &ilen); 279 if (!ireg) { 280 pr_err("icp_native: Can't find interrupt reg property"); 281 return -1; 282 } 283 284 reg_tuple_size = (of_n_addr_cells(np) + of_n_size_cells(np)) * 4; 285 if (((ilen % reg_tuple_size) != 0) 286 || (num_servers && (num_servers != (ilen / reg_tuple_size)))) { 287 pr_err("icp_native: ICP reg len (%d) != num servers (%d)", 288 ilen / reg_tuple_size, num_servers); 289 return -1; 290 } 291 292 for (i = 0; i < (ilen / reg_tuple_size); i++) { 293 struct resource r; 294 int err; 295 296 err = of_address_to_resource(np, i, &r); 297 if (err) { 298 pr_err("icp_native: Could not translate ICP MMIO" 299 " for interrupt server 0x%x (%d)\n", *indx, err); 300 return -1; 301 } 302 303 if (icp_native_map_one_cpu(*indx, r.start, resource_size(&r))) 304 return -1; 305 306 (*indx)++; 307 } 308 return 0; 309 } 310 311 static const struct icp_ops icp_native_ops = { 312 .get_irq = icp_native_get_irq, 313 .eoi = icp_native_eoi, 314 .set_priority = icp_native_set_cpu_priority, 315 .teardown_cpu = icp_native_teardown_cpu, 316 .flush_ipi = icp_native_flush_ipi, 317 #ifdef CONFIG_SMP 318 .ipi_action = icp_native_ipi_action, 319 .cause_ipi = icp_native_cause_ipi, 320 #endif 321 }; 322 323 int __init icp_native_init(void) 324 { 325 struct device_node *np; 326 u32 indx = 0; 327 int found = 0; 328 329 for_each_compatible_node(np, NULL, "ibm,ppc-xicp") 330 if (icp_native_init_one_node(np, &indx) == 0) 331 found = 1; 332 if (!found) { 333 for_each_node_by_type(np, 334 "PowerPC-External-Interrupt-Presentation") { 335 if (icp_native_init_one_node(np, &indx) == 0) 336 found = 1; 337 } 338 } 339 340 if (found == 0) 341 return -ENODEV; 342 343 icp_ops = &icp_native_ops; 344 345 return 0; 346 } 347