1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/types.h> 3 #include <linux/kernel.h> 4 #include <linux/irq.h> 5 #include <linux/smp.h> 6 #include <linux/interrupt.h> 7 #include <linux/init.h> 8 #include <linux/cpu.h> 9 #include <linux/of.h> 10 #include <linux/spinlock.h> 11 #include <linux/msi.h> 12 13 #include <asm/prom.h> 14 #include <asm/smp.h> 15 #include <asm/machdep.h> 16 #include <asm/irq.h> 17 #include <asm/errno.h> 18 #include <asm/xics.h> 19 #include <asm/rtas.h> 20 21 /* RTAS service tokens */ 22 static int ibm_get_xive; 23 static int ibm_set_xive; 24 static int ibm_int_on; 25 static int ibm_int_off; 26 27 static void ics_rtas_unmask_irq(struct irq_data *d) 28 { 29 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 30 int call_status; 31 int server; 32 33 pr_devel("xics: unmask virq %d [hw 0x%x]\n", d->irq, hw_irq); 34 35 if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) 36 return; 37 38 server = xics_get_irq_server(d->irq, irq_data_get_affinity_mask(d), 0); 39 40 call_status = rtas_call_reentrant(ibm_set_xive, 3, 1, NULL, hw_irq, 41 server, DEFAULT_PRIORITY); 42 if (call_status != 0) { 43 printk(KERN_ERR 44 "%s: ibm_set_xive irq %u server %x returned %d\n", 45 __func__, hw_irq, server, call_status); 46 return; 47 } 48 49 /* Now unmask the interrupt (often a no-op) */ 50 call_status = rtas_call_reentrant(ibm_int_on, 1, 1, NULL, hw_irq); 51 if (call_status != 0) { 52 printk(KERN_ERR "%s: ibm_int_on irq=%u returned %d\n", 53 __func__, hw_irq, call_status); 54 return; 55 } 56 } 57 58 static unsigned int ics_rtas_startup(struct irq_data *d) 59 { 60 /* unmask it */ 61 ics_rtas_unmask_irq(d); 62 return 0; 63 } 64 65 static void ics_rtas_mask_real_irq(unsigned int hw_irq) 66 { 67 int call_status; 68 69 if (hw_irq == XICS_IPI) 70 return; 71 72 call_status = rtas_call_reentrant(ibm_int_off, 1, 1, NULL, hw_irq); 73 if (call_status != 0) { 74 printk(KERN_ERR "%s: ibm_int_off irq=%u returned %d\n", 75 __func__, hw_irq, call_status); 76 return; 77 } 78 79 /* Have to set XIVE to 0xff to be able to remove a slot */ 80 call_status = rtas_call_reentrant(ibm_set_xive, 3, 1, NULL, hw_irq, 81 xics_default_server, 0xff); 82 if (call_status != 0) { 83 printk(KERN_ERR "%s: ibm_set_xive(0xff) irq=%u returned %d\n", 84 __func__, hw_irq, call_status); 85 return; 86 } 87 } 88 89 static void ics_rtas_mask_irq(struct irq_data *d) 90 { 91 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 92 93 pr_devel("xics: mask virq %d [hw 0x%x]\n", d->irq, hw_irq); 94 95 if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) 96 return; 97 ics_rtas_mask_real_irq(hw_irq); 98 } 99 100 static int ics_rtas_set_affinity(struct irq_data *d, 101 const struct cpumask *cpumask, 102 bool force) 103 { 104 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 105 int status; 106 int xics_status[2]; 107 int irq_server; 108 109 if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) 110 return -1; 111 112 status = rtas_call_reentrant(ibm_get_xive, 1, 3, xics_status, hw_irq); 113 114 if (status) { 115 printk(KERN_ERR "%s: ibm,get-xive irq=%u returns %d\n", 116 __func__, hw_irq, status); 117 return -1; 118 } 119 120 irq_server = xics_get_irq_server(d->irq, cpumask, 1); 121 if (irq_server == -1) { 122 pr_warn("%s: No online cpus in the mask %*pb for irq %d\n", 123 __func__, cpumask_pr_args(cpumask), d->irq); 124 return -1; 125 } 126 127 pr_debug("%s: irq %d [hw 0x%x] server: 0x%x\n", __func__, d->irq, 128 hw_irq, irq_server); 129 130 status = rtas_call_reentrant(ibm_set_xive, 3, 1, NULL, 131 hw_irq, irq_server, xics_status[1]); 132 133 if (status) { 134 printk(KERN_ERR "%s: ibm,set-xive irq=%u returns %d\n", 135 __func__, hw_irq, status); 136 return -1; 137 } 138 139 return IRQ_SET_MASK_OK; 140 } 141 142 static struct irq_chip ics_rtas_irq_chip = { 143 .name = "XICS", 144 .irq_startup = ics_rtas_startup, 145 .irq_mask = ics_rtas_mask_irq, 146 .irq_unmask = ics_rtas_unmask_irq, 147 .irq_eoi = NULL, /* Patched at init time */ 148 .irq_set_affinity = ics_rtas_set_affinity, 149 .irq_set_type = xics_set_irq_type, 150 .irq_retrigger = xics_retrigger, 151 }; 152 153 static int ics_rtas_check(struct ics *ics, unsigned int hw_irq) 154 { 155 int status[2]; 156 int rc; 157 158 if (WARN_ON(hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)) 159 return -EINVAL; 160 161 /* Check if RTAS knows about this interrupt */ 162 rc = rtas_call_reentrant(ibm_get_xive, 1, 3, status, hw_irq); 163 if (rc) 164 return -ENXIO; 165 166 return 0; 167 } 168 169 static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec) 170 { 171 ics_rtas_mask_real_irq(vec); 172 } 173 174 static long ics_rtas_get_server(struct ics *ics, unsigned long vec) 175 { 176 int rc, status[2]; 177 178 rc = rtas_call_reentrant(ibm_get_xive, 1, 3, status, vec); 179 if (rc) 180 return -1; 181 return status[0]; 182 } 183 184 static int ics_rtas_host_match(struct ics *ics, struct device_node *node) 185 { 186 /* IBM machines have interrupt parents of various funky types for things 187 * like vdevices, events, etc... The trick we use here is to match 188 * everything here except the legacy 8259 which is compatible "chrp,iic" 189 */ 190 return !of_device_is_compatible(node, "chrp,iic"); 191 } 192 193 /* Only one global & state struct ics */ 194 static struct ics ics_rtas = { 195 .check = ics_rtas_check, 196 .mask_unknown = ics_rtas_mask_unknown, 197 .get_server = ics_rtas_get_server, 198 .host_match = ics_rtas_host_match, 199 .chip = &ics_rtas_irq_chip, 200 }; 201 202 __init int ics_rtas_init(void) 203 { 204 ibm_get_xive = rtas_token("ibm,get-xive"); 205 ibm_set_xive = rtas_token("ibm,set-xive"); 206 ibm_int_on = rtas_token("ibm,int-on"); 207 ibm_int_off = rtas_token("ibm,int-off"); 208 209 /* We enable the RTAS "ICS" if RTAS is present with the 210 * appropriate tokens 211 */ 212 if (ibm_get_xive == RTAS_UNKNOWN_SERVICE || 213 ibm_set_xive == RTAS_UNKNOWN_SERVICE) 214 return -ENODEV; 215 216 /* We need to patch our irq chip's EOI to point to the 217 * right ICP 218 */ 219 ics_rtas_irq_chip.irq_eoi = icp_ops->eoi; 220 221 /* Register ourselves */ 222 xics_register_ics(&ics_rtas); 223 224 return 0; 225 } 226 227