1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 2011 IBM Corporation. 4 */ 5 #include <linux/types.h> 6 #include <linux/kernel.h> 7 #include <linux/irq.h> 8 #include <linux/smp.h> 9 #include <linux/interrupt.h> 10 #include <linux/irqdomain.h> 11 #include <linux/cpu.h> 12 #include <linux/of.h> 13 14 #include <asm/smp.h> 15 #include <asm/irq.h> 16 #include <asm/errno.h> 17 #include <asm/xics.h> 18 #include <asm/io.h> 19 #include <asm/hvcall.h> 20 21 static inline unsigned int icp_hv_get_xirr(unsigned char cppr) 22 { 23 unsigned long retbuf[PLPAR_HCALL_BUFSIZE]; 24 long rc; 25 unsigned int ret = XICS_IRQ_SPURIOUS; 26 27 rc = plpar_hcall(H_XIRR, retbuf, cppr); 28 if (rc == H_SUCCESS) { 29 ret = (unsigned int)retbuf[0]; 30 } else { 31 pr_err("%s: bad return code xirr cppr=0x%x returned %ld\n", 32 __func__, cppr, rc); 33 WARN_ON_ONCE(1); 34 } 35 36 return ret; 37 } 38 39 static inline void icp_hv_set_cppr(u8 value) 40 { 41 long rc = plpar_hcall_norets(H_CPPR, value); 42 if (rc != H_SUCCESS) { 43 pr_err("%s: bad return code cppr cppr=0x%x returned %ld\n", 44 __func__, value, rc); 45 WARN_ON_ONCE(1); 46 } 47 } 48 49 static inline void icp_hv_set_xirr(unsigned int value) 50 { 51 long rc = plpar_hcall_norets(H_EOI, value); 52 if (rc != H_SUCCESS) { 53 pr_err("%s: bad return code eoi xirr=0x%x returned %ld\n", 54 __func__, value, rc); 55 WARN_ON_ONCE(1); 56 icp_hv_set_cppr(value >> 24); 57 } 58 } 59 60 static inline void icp_hv_set_qirr(int n_cpu , u8 value) 61 { 62 int hw_cpu = get_hard_smp_processor_id(n_cpu); 63 long rc; 64 65 /* Make sure all previous accesses are ordered before IPI sending */ 66 mb(); 67 rc = plpar_hcall_norets(H_IPI, hw_cpu, value); 68 if (rc != H_SUCCESS) { 69 pr_err("%s: bad return code qirr cpu=%d hw_cpu=%d mfrr=0x%x " 70 "returned %ld\n", __func__, n_cpu, hw_cpu, value, rc); 71 WARN_ON_ONCE(1); 72 } 73 } 74 75 static void icp_hv_eoi(struct irq_data *d) 76 { 77 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 78 79 iosync(); 80 icp_hv_set_xirr((xics_pop_cppr() << 24) | hw_irq); 81 } 82 83 static void icp_hv_teardown_cpu(void) 84 { 85 int cpu = smp_processor_id(); 86 87 /* Clear any pending IPI */ 88 icp_hv_set_qirr(cpu, 0xff); 89 } 90 91 static void icp_hv_flush_ipi(void) 92 { 93 /* We take the ipi irq but and never return so we 94 * need to EOI the IPI, but want to leave our priority 0 95 * 96 * should we check all the other interrupts too? 97 * should we be flagging idle loop instead? 98 * or creating some task to be scheduled? 99 */ 100 101 icp_hv_set_xirr((0x00 << 24) | XICS_IPI); 102 } 103 104 static unsigned int icp_hv_get_irq(void) 105 { 106 unsigned int xirr = icp_hv_get_xirr(xics_cppr_top()); 107 unsigned int vec = xirr & 0x00ffffff; 108 unsigned int irq; 109 110 if (vec == XICS_IRQ_SPURIOUS) 111 return 0; 112 113 irq = irq_find_mapping(xics_host, vec); 114 if (likely(irq)) { 115 xics_push_cppr(vec); 116 return irq; 117 } 118 119 /* We don't have a linux mapping, so have rtas mask it. */ 120 xics_mask_unknown_vec(vec); 121 122 /* We might learn about it later, so EOI it */ 123 icp_hv_set_xirr(xirr); 124 125 return 0; 126 } 127 128 static void icp_hv_set_cpu_priority(unsigned char cppr) 129 { 130 xics_set_base_cppr(cppr); 131 icp_hv_set_cppr(cppr); 132 iosync(); 133 } 134 135 #ifdef CONFIG_SMP 136 137 static void icp_hv_cause_ipi(int cpu) 138 { 139 icp_hv_set_qirr(cpu, IPI_PRIORITY); 140 } 141 142 static irqreturn_t icp_hv_ipi_action(int irq, void *dev_id) 143 { 144 int cpu = smp_processor_id(); 145 146 icp_hv_set_qirr(cpu, 0xff); 147 148 return smp_ipi_demux(); 149 } 150 151 #endif /* CONFIG_SMP */ 152 153 static const struct icp_ops icp_hv_ops = { 154 .get_irq = icp_hv_get_irq, 155 .eoi = icp_hv_eoi, 156 .set_priority = icp_hv_set_cpu_priority, 157 .teardown_cpu = icp_hv_teardown_cpu, 158 .flush_ipi = icp_hv_flush_ipi, 159 #ifdef CONFIG_SMP 160 .ipi_action = icp_hv_ipi_action, 161 .cause_ipi = icp_hv_cause_ipi, 162 #endif 163 }; 164 165 int __init icp_hv_init(void) 166 { 167 struct device_node *np; 168 169 np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xicp"); 170 if (!np) 171 np = of_find_node_by_type(NULL, 172 "PowerPC-External-Interrupt-Presentation"); 173 if (!np) 174 return -ENODEV; 175 176 icp_ops = &icp_hv_ops; 177 178 of_node_put(np); 179 return 0; 180 } 181 182