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 int ics_rtas_map(struct ics *ics, unsigned int virq); 28 static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec); 29 static long ics_rtas_get_server(struct ics *ics, unsigned long vec); 30 static int ics_rtas_host_match(struct ics *ics, struct device_node *node); 31 32 /* Only one global & state struct ics */ 33 static struct ics ics_rtas = { 34 .map = ics_rtas_map, 35 .mask_unknown = ics_rtas_mask_unknown, 36 .get_server = ics_rtas_get_server, 37 .host_match = ics_rtas_host_match, 38 }; 39 40 static void ics_rtas_unmask_irq(struct irq_data *d) 41 { 42 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 43 int call_status; 44 int server; 45 46 pr_devel("xics: unmask virq %d [hw 0x%x]\n", d->irq, hw_irq); 47 48 if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) 49 return; 50 51 server = xics_get_irq_server(d->irq, irq_data_get_affinity_mask(d), 0); 52 53 call_status = rtas_call_reentrant(ibm_set_xive, 3, 1, NULL, hw_irq, 54 server, DEFAULT_PRIORITY); 55 if (call_status != 0) { 56 printk(KERN_ERR 57 "%s: ibm_set_xive irq %u server %x returned %d\n", 58 __func__, hw_irq, server, call_status); 59 return; 60 } 61 62 /* Now unmask the interrupt (often a no-op) */ 63 call_status = rtas_call_reentrant(ibm_int_on, 1, 1, NULL, hw_irq); 64 if (call_status != 0) { 65 printk(KERN_ERR "%s: ibm_int_on irq=%u returned %d\n", 66 __func__, hw_irq, call_status); 67 return; 68 } 69 } 70 71 static unsigned int ics_rtas_startup(struct irq_data *d) 72 { 73 #ifdef CONFIG_PCI_MSI 74 /* 75 * The generic MSI code returns with the interrupt disabled on the 76 * card, using the MSI mask bits. Firmware doesn't appear to unmask 77 * at that level, so we do it here by hand. 78 */ 79 if (irq_data_get_msi_desc(d)) 80 pci_msi_unmask_irq(d); 81 #endif 82 /* unmask it */ 83 ics_rtas_unmask_irq(d); 84 return 0; 85 } 86 87 static void ics_rtas_mask_real_irq(unsigned int hw_irq) 88 { 89 int call_status; 90 91 if (hw_irq == XICS_IPI) 92 return; 93 94 call_status = rtas_call_reentrant(ibm_int_off, 1, 1, NULL, hw_irq); 95 if (call_status != 0) { 96 printk(KERN_ERR "%s: ibm_int_off irq=%u returned %d\n", 97 __func__, hw_irq, call_status); 98 return; 99 } 100 101 /* Have to set XIVE to 0xff to be able to remove a slot */ 102 call_status = rtas_call_reentrant(ibm_set_xive, 3, 1, NULL, hw_irq, 103 xics_default_server, 0xff); 104 if (call_status != 0) { 105 printk(KERN_ERR "%s: ibm_set_xive(0xff) irq=%u returned %d\n", 106 __func__, hw_irq, call_status); 107 return; 108 } 109 } 110 111 static void ics_rtas_mask_irq(struct irq_data *d) 112 { 113 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 114 115 pr_devel("xics: mask virq %d [hw 0x%x]\n", d->irq, hw_irq); 116 117 if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) 118 return; 119 ics_rtas_mask_real_irq(hw_irq); 120 } 121 122 static int ics_rtas_set_affinity(struct irq_data *d, 123 const struct cpumask *cpumask, 124 bool force) 125 { 126 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 127 int status; 128 int xics_status[2]; 129 int irq_server; 130 131 if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) 132 return -1; 133 134 status = rtas_call_reentrant(ibm_get_xive, 1, 3, xics_status, hw_irq); 135 136 if (status) { 137 printk(KERN_ERR "%s: ibm,get-xive irq=%u returns %d\n", 138 __func__, hw_irq, status); 139 return -1; 140 } 141 142 irq_server = xics_get_irq_server(d->irq, cpumask, 1); 143 if (irq_server == -1) { 144 pr_warn("%s: No online cpus in the mask %*pb for irq %d\n", 145 __func__, cpumask_pr_args(cpumask), d->irq); 146 return -1; 147 } 148 149 status = rtas_call_reentrant(ibm_set_xive, 3, 1, NULL, 150 hw_irq, irq_server, xics_status[1]); 151 152 if (status) { 153 printk(KERN_ERR "%s: ibm,set-xive irq=%u returns %d\n", 154 __func__, hw_irq, status); 155 return -1; 156 } 157 158 return IRQ_SET_MASK_OK; 159 } 160 161 static struct irq_chip ics_rtas_irq_chip = { 162 .name = "XICS", 163 .irq_startup = ics_rtas_startup, 164 .irq_mask = ics_rtas_mask_irq, 165 .irq_unmask = ics_rtas_unmask_irq, 166 .irq_eoi = NULL, /* Patched at init time */ 167 .irq_set_affinity = ics_rtas_set_affinity, 168 .irq_set_type = xics_set_irq_type, 169 .irq_retrigger = xics_retrigger, 170 }; 171 172 static int ics_rtas_map(struct ics *ics, unsigned int virq) 173 { 174 unsigned int hw_irq = (unsigned int)virq_to_hw(virq); 175 int status[2]; 176 int rc; 177 178 if (WARN_ON(hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)) 179 return -EINVAL; 180 181 /* Check if RTAS knows about this interrupt */ 182 rc = rtas_call_reentrant(ibm_get_xive, 1, 3, status, hw_irq); 183 if (rc) 184 return -ENXIO; 185 186 irq_set_chip_and_handler(virq, &ics_rtas_irq_chip, handle_fasteoi_irq); 187 irq_set_chip_data(virq, &ics_rtas); 188 189 return 0; 190 } 191 192 static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec) 193 { 194 ics_rtas_mask_real_irq(vec); 195 } 196 197 static long ics_rtas_get_server(struct ics *ics, unsigned long vec) 198 { 199 int rc, status[2]; 200 201 rc = rtas_call_reentrant(ibm_get_xive, 1, 3, status, vec); 202 if (rc) 203 return -1; 204 return status[0]; 205 } 206 207 static int ics_rtas_host_match(struct ics *ics, struct device_node *node) 208 { 209 /* IBM machines have interrupt parents of various funky types for things 210 * like vdevices, events, etc... The trick we use here is to match 211 * everything here except the legacy 8259 which is compatible "chrp,iic" 212 */ 213 return !of_device_is_compatible(node, "chrp,iic"); 214 } 215 216 __init int ics_rtas_init(void) 217 { 218 ibm_get_xive = rtas_token("ibm,get-xive"); 219 ibm_set_xive = rtas_token("ibm,set-xive"); 220 ibm_int_on = rtas_token("ibm,int-on"); 221 ibm_int_off = rtas_token("ibm,int-off"); 222 223 /* We enable the RTAS "ICS" if RTAS is present with the 224 * appropriate tokens 225 */ 226 if (ibm_get_xive == RTAS_UNKNOWN_SERVICE || 227 ibm_set_xive == RTAS_UNKNOWN_SERVICE) 228 return -ENODEV; 229 230 /* We need to patch our irq chip's EOI to point to the 231 * right ICP 232 */ 233 ics_rtas_irq_chip.irq_eoi = icp_ops->eoi; 234 235 /* Register ourselves */ 236 xics_register_ics(&ics_rtas); 237 238 return 0; 239 } 240 241