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 0; 128 129 irq = irq_find_mapping(xics_host, vec); 130 if (likely(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 0; 142 } 143 144 #ifdef CONFIG_SMP 145 146 static void icp_native_cause_ipi(int cpu) 147 { 148 kvmppc_set_host_ipi(cpu, 1); 149 icp_native_set_qirr(cpu, IPI_PRIORITY); 150 } 151 152 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE 153 void icp_native_cause_ipi_rm(int cpu) 154 { 155 /* 156 * Currently not used to send IPIs to another CPU 157 * on the same core. Only caller is KVM real mode. 158 * Need the physical address of the XICS to be 159 * previously saved in kvm_hstate in the paca. 160 */ 161 void __iomem *xics_phys; 162 163 /* 164 * Just like the cause_ipi functions, it is required to 165 * include a full barrier before causing the IPI. 166 */ 167 xics_phys = paca[cpu].kvm_hstate.xics_phys; 168 mb(); 169 __raw_rm_writeb(IPI_PRIORITY, xics_phys + XICS_MFRR); 170 } 171 #endif 172 173 /* 174 * Called when an interrupt is received on an off-line CPU to 175 * clear the interrupt, so that the CPU can go back to nap mode. 176 */ 177 void icp_native_flush_interrupt(void) 178 { 179 unsigned int xirr = icp_native_get_xirr(); 180 unsigned int vec = xirr & 0x00ffffff; 181 182 if (vec == XICS_IRQ_SPURIOUS) 183 return; 184 if (vec == XICS_IPI) { 185 /* Clear pending IPI */ 186 int cpu = smp_processor_id(); 187 kvmppc_set_host_ipi(cpu, 0); 188 icp_native_set_qirr(cpu, 0xff); 189 } else { 190 pr_err("XICS: hw interrupt 0x%x to offline cpu, disabling\n", 191 vec); 192 xics_mask_unknown_vec(vec); 193 } 194 /* EOI the interrupt */ 195 icp_native_set_xirr(xirr); 196 } 197 198 void xics_wake_cpu(int cpu) 199 { 200 icp_native_set_qirr(cpu, IPI_PRIORITY); 201 } 202 EXPORT_SYMBOL_GPL(xics_wake_cpu); 203 204 static irqreturn_t icp_native_ipi_action(int irq, void *dev_id) 205 { 206 int cpu = smp_processor_id(); 207 208 kvmppc_set_host_ipi(cpu, 0); 209 icp_native_set_qirr(cpu, 0xff); 210 211 return smp_ipi_demux(); 212 } 213 214 #endif /* CONFIG_SMP */ 215 216 static int __init icp_native_map_one_cpu(int hw_id, unsigned long addr, 217 unsigned long size) 218 { 219 char *rname; 220 int i, cpu = -1; 221 222 /* This may look gross but it's good enough for now, we don't quite 223 * have a hard -> linux processor id matching. 224 */ 225 for_each_possible_cpu(i) { 226 if (!cpu_present(i)) 227 continue; 228 if (hw_id == get_hard_smp_processor_id(i)) { 229 cpu = i; 230 break; 231 } 232 } 233 234 /* Fail, skip that CPU. Don't print, it's normal, some XICS come up 235 * with way more entries in there than you have CPUs 236 */ 237 if (cpu == -1) 238 return 0; 239 240 rname = kasprintf(GFP_KERNEL, "CPU %d [0x%x] Interrupt Presentation", 241 cpu, hw_id); 242 243 if (!request_mem_region(addr, size, rname)) { 244 pr_warning("icp_native: Could not reserve ICP MMIO" 245 " for CPU %d, interrupt server #0x%x\n", 246 cpu, hw_id); 247 return -EBUSY; 248 } 249 250 icp_native_regs[cpu] = ioremap(addr, size); 251 kvmppc_set_xics_phys(cpu, addr); 252 if (!icp_native_regs[cpu]) { 253 pr_warning("icp_native: Failed ioremap for CPU %d, " 254 "interrupt server #0x%x, addr %#lx\n", 255 cpu, hw_id, addr); 256 release_mem_region(addr, size); 257 return -ENOMEM; 258 } 259 return 0; 260 } 261 262 static int __init icp_native_init_one_node(struct device_node *np, 263 unsigned int *indx) 264 { 265 unsigned int ilen; 266 const __be32 *ireg; 267 int i; 268 int reg_tuple_size; 269 int num_servers = 0; 270 271 /* This code does the theorically broken assumption that the interrupt 272 * server numbers are the same as the hard CPU numbers. 273 * This happens to be the case so far but we are playing with fire... 274 * should be fixed one of these days. -BenH. 275 */ 276 ireg = of_get_property(np, "ibm,interrupt-server-ranges", &ilen); 277 278 /* Do that ever happen ? we'll know soon enough... but even good'old 279 * f80 does have that property .. 280 */ 281 WARN_ON((ireg == NULL) || (ilen != 2*sizeof(u32))); 282 283 if (ireg) { 284 *indx = of_read_number(ireg, 1); 285 if (ilen >= 2*sizeof(u32)) 286 num_servers = of_read_number(ireg + 1, 1); 287 } 288 289 ireg = of_get_property(np, "reg", &ilen); 290 if (!ireg) { 291 pr_err("icp_native: Can't find interrupt reg property"); 292 return -1; 293 } 294 295 reg_tuple_size = (of_n_addr_cells(np) + of_n_size_cells(np)) * 4; 296 if (((ilen % reg_tuple_size) != 0) 297 || (num_servers && (num_servers != (ilen / reg_tuple_size)))) { 298 pr_err("icp_native: ICP reg len (%d) != num servers (%d)", 299 ilen / reg_tuple_size, num_servers); 300 return -1; 301 } 302 303 for (i = 0; i < (ilen / reg_tuple_size); i++) { 304 struct resource r; 305 int err; 306 307 err = of_address_to_resource(np, i, &r); 308 if (err) { 309 pr_err("icp_native: Could not translate ICP MMIO" 310 " for interrupt server 0x%x (%d)\n", *indx, err); 311 return -1; 312 } 313 314 if (icp_native_map_one_cpu(*indx, r.start, resource_size(&r))) 315 return -1; 316 317 (*indx)++; 318 } 319 return 0; 320 } 321 322 static const struct icp_ops icp_native_ops = { 323 .get_irq = icp_native_get_irq, 324 .eoi = icp_native_eoi, 325 .set_priority = icp_native_set_cpu_priority, 326 .teardown_cpu = icp_native_teardown_cpu, 327 .flush_ipi = icp_native_flush_ipi, 328 #ifdef CONFIG_SMP 329 .ipi_action = icp_native_ipi_action, 330 .cause_ipi = icp_native_cause_ipi, 331 #endif 332 }; 333 334 int __init icp_native_init(void) 335 { 336 struct device_node *np; 337 u32 indx = 0; 338 int found = 0; 339 340 for_each_compatible_node(np, NULL, "ibm,ppc-xicp") 341 if (icp_native_init_one_node(np, &indx) == 0) 342 found = 1; 343 if (!found) { 344 for_each_node_by_type(np, 345 "PowerPC-External-Interrupt-Presentation") { 346 if (icp_native_init_one_node(np, &indx) == 0) 347 found = 1; 348 } 349 } 350 351 if (found == 0) 352 return -ENODEV; 353 354 icp_ops = &icp_native_ops; 355 356 return 0; 357 } 358