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