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