1 #include <linux/types.h> 2 #include <linux/kernel.h> 3 #include <linux/irq.h> 4 #include <linux/smp.h> 5 #include <linux/interrupt.h> 6 #include <linux/init.h> 7 #include <linux/cpu.h> 8 #include <linux/of.h> 9 #include <linux/spinlock.h> 10 #include <linux/msi.h> 11 12 #include <asm/prom.h> 13 #include <asm/smp.h> 14 #include <asm/machdep.h> 15 #include <asm/irq.h> 16 #include <asm/errno.h> 17 #include <asm/xics.h> 18 #include <asm/rtas.h> 19 20 /* RTAS service tokens */ 21 static int ibm_get_xive; 22 static int ibm_set_xive; 23 static int ibm_int_on; 24 static int ibm_int_off; 25 26 static int ics_rtas_map(struct ics *ics, unsigned int virq); 27 static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec); 28 static long ics_rtas_get_server(struct ics *ics, unsigned long vec); 29 static int ics_rtas_host_match(struct ics *ics, struct device_node *node); 30 31 /* Only one global & state struct ics */ 32 static struct ics ics_rtas = { 33 .map = ics_rtas_map, 34 .mask_unknown = ics_rtas_mask_unknown, 35 .get_server = ics_rtas_get_server, 36 .host_match = ics_rtas_host_match, 37 }; 38 39 static void ics_rtas_unmask_irq(struct irq_data *d) 40 { 41 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 42 int call_status; 43 int server; 44 45 pr_devel("xics: unmask virq %d [hw 0x%x]\n", d->irq, hw_irq); 46 47 if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) 48 return; 49 50 server = xics_get_irq_server(d->irq, irq_data_get_affinity_mask(d), 0); 51 52 call_status = rtas_call(ibm_set_xive, 3, 1, NULL, hw_irq, server, 53 DEFAULT_PRIORITY); 54 if (call_status != 0) { 55 printk(KERN_ERR 56 "%s: ibm_set_xive irq %u server %x returned %d\n", 57 __func__, hw_irq, server, call_status); 58 return; 59 } 60 61 /* Now unmask the interrupt (often a no-op) */ 62 call_status = rtas_call(ibm_int_on, 1, 1, NULL, hw_irq); 63 if (call_status != 0) { 64 printk(KERN_ERR "%s: ibm_int_on irq=%u returned %d\n", 65 __func__, hw_irq, call_status); 66 return; 67 } 68 } 69 70 static unsigned int ics_rtas_startup(struct irq_data *d) 71 { 72 #ifdef CONFIG_PCI_MSI 73 /* 74 * The generic MSI code returns with the interrupt disabled on the 75 * card, using the MSI mask bits. Firmware doesn't appear to unmask 76 * at that level, so we do it here by hand. 77 */ 78 if (irq_data_get_msi_desc(d)) 79 pci_msi_unmask_irq(d); 80 #endif 81 /* unmask it */ 82 ics_rtas_unmask_irq(d); 83 return 0; 84 } 85 86 static void ics_rtas_mask_real_irq(unsigned int hw_irq) 87 { 88 int call_status; 89 90 if (hw_irq == XICS_IPI) 91 return; 92 93 call_status = rtas_call(ibm_int_off, 1, 1, NULL, hw_irq); 94 if (call_status != 0) { 95 printk(KERN_ERR "%s: ibm_int_off irq=%u returned %d\n", 96 __func__, hw_irq, call_status); 97 return; 98 } 99 100 /* Have to set XIVE to 0xff to be able to remove a slot */ 101 call_status = rtas_call(ibm_set_xive, 3, 1, NULL, hw_irq, 102 xics_default_server, 0xff); 103 if (call_status != 0) { 104 printk(KERN_ERR "%s: ibm_set_xive(0xff) irq=%u returned %d\n", 105 __func__, hw_irq, call_status); 106 return; 107 } 108 } 109 110 static void ics_rtas_mask_irq(struct irq_data *d) 111 { 112 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 113 114 pr_devel("xics: mask virq %d [hw 0x%x]\n", d->irq, hw_irq); 115 116 if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) 117 return; 118 ics_rtas_mask_real_irq(hw_irq); 119 } 120 121 static int ics_rtas_set_affinity(struct irq_data *d, 122 const struct cpumask *cpumask, 123 bool force) 124 { 125 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 126 int status; 127 int xics_status[2]; 128 int irq_server; 129 130 if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) 131 return -1; 132 133 status = rtas_call(ibm_get_xive, 1, 3, xics_status, hw_irq); 134 135 if (status) { 136 printk(KERN_ERR "%s: ibm,get-xive irq=%u returns %d\n", 137 __func__, hw_irq, status); 138 return -1; 139 } 140 141 irq_server = xics_get_irq_server(d->irq, cpumask, 1); 142 if (irq_server == -1) { 143 pr_warning("%s: No online cpus in the mask %*pb for irq %d\n", 144 __func__, cpumask_pr_args(cpumask), d->irq); 145 return -1; 146 } 147 148 status = rtas_call(ibm_set_xive, 3, 1, NULL, 149 hw_irq, irq_server, xics_status[1]); 150 151 if (status) { 152 printk(KERN_ERR "%s: ibm,set-xive irq=%u returns %d\n", 153 __func__, hw_irq, status); 154 return -1; 155 } 156 157 return IRQ_SET_MASK_OK; 158 } 159 160 static struct irq_chip ics_rtas_irq_chip = { 161 .name = "XICS", 162 .irq_startup = ics_rtas_startup, 163 .irq_mask = ics_rtas_mask_irq, 164 .irq_unmask = ics_rtas_unmask_irq, 165 .irq_eoi = NULL, /* Patched at init time */ 166 .irq_set_affinity = ics_rtas_set_affinity 167 }; 168 169 static int ics_rtas_map(struct ics *ics, unsigned int virq) 170 { 171 unsigned int hw_irq = (unsigned int)virq_to_hw(virq); 172 int status[2]; 173 int rc; 174 175 if (WARN_ON(hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)) 176 return -EINVAL; 177 178 /* Check if RTAS knows about this interrupt */ 179 rc = rtas_call(ibm_get_xive, 1, 3, status, hw_irq); 180 if (rc) 181 return -ENXIO; 182 183 irq_set_chip_and_handler(virq, &ics_rtas_irq_chip, handle_fasteoi_irq); 184 irq_set_chip_data(virq, &ics_rtas); 185 186 return 0; 187 } 188 189 static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec) 190 { 191 ics_rtas_mask_real_irq(vec); 192 } 193 194 static long ics_rtas_get_server(struct ics *ics, unsigned long vec) 195 { 196 int rc, status[2]; 197 198 rc = rtas_call(ibm_get_xive, 1, 3, status, vec); 199 if (rc) 200 return -1; 201 return status[0]; 202 } 203 204 static int ics_rtas_host_match(struct ics *ics, struct device_node *node) 205 { 206 /* IBM machines have interrupt parents of various funky types for things 207 * like vdevices, events, etc... The trick we use here is to match 208 * everything here except the legacy 8259 which is compatible "chrp,iic" 209 */ 210 return !of_device_is_compatible(node, "chrp,iic"); 211 } 212 213 __init int ics_rtas_init(void) 214 { 215 ibm_get_xive = rtas_token("ibm,get-xive"); 216 ibm_set_xive = rtas_token("ibm,set-xive"); 217 ibm_int_on = rtas_token("ibm,int-on"); 218 ibm_int_off = rtas_token("ibm,int-off"); 219 220 /* We enable the RTAS "ICS" if RTAS is present with the 221 * appropriate tokens 222 */ 223 if (ibm_get_xive == RTAS_UNKNOWN_SERVICE || 224 ibm_set_xive == RTAS_UNKNOWN_SERVICE) 225 return -ENODEV; 226 227 /* We need to patch our irq chip's EOI to point to the 228 * right ICP 229 */ 230 ics_rtas_irq_chip.irq_eoi = icp_ops->eoi; 231 232 /* Register ourselves */ 233 xics_register_ics(&ics_rtas); 234 235 return 0; 236 } 237 238