1 /* 2 * Copyright 2011 IBM Corporation. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 */ 10 #include <linux/types.h> 11 #include <linux/kernel.h> 12 #include <linux/irq.h> 13 #include <linux/smp.h> 14 #include <linux/interrupt.h> 15 #include <linux/init.h> 16 #include <linux/cpu.h> 17 #include <linux/of.h> 18 19 #include <asm/smp.h> 20 #include <asm/irq.h> 21 #include <asm/errno.h> 22 #include <asm/xics.h> 23 #include <asm/io.h> 24 #include <asm/hvcall.h> 25 26 static inline unsigned int icp_hv_get_xirr(unsigned char cppr) 27 { 28 unsigned long retbuf[PLPAR_HCALL_BUFSIZE]; 29 long rc; 30 unsigned int ret = XICS_IRQ_SPURIOUS; 31 32 rc = plpar_hcall(H_XIRR, retbuf, cppr); 33 if (rc == H_SUCCESS) { 34 ret = (unsigned int)retbuf[0]; 35 } else { 36 pr_err("%s: bad return code xirr cppr=0x%x returned %ld\n", 37 __func__, cppr, rc); 38 WARN_ON_ONCE(1); 39 } 40 41 return ret; 42 } 43 44 static inline void icp_hv_set_cppr(u8 value) 45 { 46 long rc = plpar_hcall_norets(H_CPPR, value); 47 if (rc != H_SUCCESS) { 48 pr_err("%s: bad return code cppr cppr=0x%x returned %ld\n", 49 __func__, value, rc); 50 WARN_ON_ONCE(1); 51 } 52 } 53 54 static inline void icp_hv_set_xirr(unsigned int value) 55 { 56 long rc = plpar_hcall_norets(H_EOI, value); 57 if (rc != H_SUCCESS) { 58 pr_err("%s: bad return code eoi xirr=0x%x returned %ld\n", 59 __func__, value, rc); 60 WARN_ON_ONCE(1); 61 icp_hv_set_cppr(value >> 24); 62 } 63 } 64 65 static inline void icp_hv_set_qirr(int n_cpu , u8 value) 66 { 67 int hw_cpu = get_hard_smp_processor_id(n_cpu); 68 long rc; 69 70 /* Make sure all previous accesses are ordered before IPI sending */ 71 mb(); 72 rc = plpar_hcall_norets(H_IPI, hw_cpu, value); 73 if (rc != H_SUCCESS) { 74 pr_err("%s: bad return code qirr cpu=%d hw_cpu=%d mfrr=0x%x " 75 "returned %ld\n", __func__, n_cpu, hw_cpu, value, rc); 76 WARN_ON_ONCE(1); 77 } 78 } 79 80 static void icp_hv_eoi(struct irq_data *d) 81 { 82 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 83 84 iosync(); 85 icp_hv_set_xirr((xics_pop_cppr() << 24) | hw_irq); 86 } 87 88 static void icp_hv_teardown_cpu(void) 89 { 90 int cpu = smp_processor_id(); 91 92 /* Clear any pending IPI */ 93 icp_hv_set_qirr(cpu, 0xff); 94 } 95 96 static void icp_hv_flush_ipi(void) 97 { 98 /* We take the ipi irq but and never return so we 99 * need to EOI the IPI, but want to leave our priority 0 100 * 101 * should we check all the other interrupts too? 102 * should we be flagging idle loop instead? 103 * or creating some task to be scheduled? 104 */ 105 106 icp_hv_set_xirr((0x00 << 24) | XICS_IPI); 107 } 108 109 static unsigned int icp_hv_get_irq(void) 110 { 111 unsigned int xirr = icp_hv_get_xirr(xics_cppr_top()); 112 unsigned int vec = xirr & 0x00ffffff; 113 unsigned int irq; 114 115 if (vec == XICS_IRQ_SPURIOUS) 116 return NO_IRQ; 117 118 irq = irq_find_mapping(xics_host, vec); 119 if (likely(irq != NO_IRQ)) { 120 xics_push_cppr(vec); 121 return irq; 122 } 123 124 /* We don't have a linux mapping, so have rtas mask it. */ 125 xics_mask_unknown_vec(vec); 126 127 /* We might learn about it later, so EOI it */ 128 icp_hv_set_xirr(xirr); 129 130 return NO_IRQ; 131 } 132 133 static void icp_hv_set_cpu_priority(unsigned char cppr) 134 { 135 xics_set_base_cppr(cppr); 136 icp_hv_set_cppr(cppr); 137 iosync(); 138 } 139 140 #ifdef CONFIG_SMP 141 142 static void icp_hv_cause_ipi(int cpu, unsigned long data) 143 { 144 icp_hv_set_qirr(cpu, IPI_PRIORITY); 145 } 146 147 static irqreturn_t icp_hv_ipi_action(int irq, void *dev_id) 148 { 149 int cpu = smp_processor_id(); 150 151 icp_hv_set_qirr(cpu, 0xff); 152 153 return smp_ipi_demux(); 154 } 155 156 #endif /* CONFIG_SMP */ 157 158 static const struct icp_ops icp_hv_ops = { 159 .get_irq = icp_hv_get_irq, 160 .eoi = icp_hv_eoi, 161 .set_priority = icp_hv_set_cpu_priority, 162 .teardown_cpu = icp_hv_teardown_cpu, 163 .flush_ipi = icp_hv_flush_ipi, 164 #ifdef CONFIG_SMP 165 .ipi_action = icp_hv_ipi_action, 166 .cause_ipi = icp_hv_cause_ipi, 167 #endif 168 }; 169 170 int icp_hv_init(void) 171 { 172 struct device_node *np; 173 174 np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xicp"); 175 if (!np) 176 np = of_find_node_by_type(NULL, 177 "PowerPC-External-Interrupt-Presentation"); 178 if (!np) 179 return -ENODEV; 180 181 icp_ops = &icp_hv_ops; 182 183 return 0; 184 } 185 186