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 31 rc = plpar_hcall(H_XIRR, retbuf, cppr); 32 if (rc != H_SUCCESS) 33 panic(" bad return code xirr - rc = %lx\n", rc); 34 return (unsigned int)retbuf[0]; 35 } 36 37 static inline void icp_hv_set_xirr(unsigned int value) 38 { 39 long rc = plpar_hcall_norets(H_EOI, value); 40 if (rc != H_SUCCESS) 41 panic("bad return code EOI - rc = %ld, value=%x\n", rc, value); 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 panic("bad return code cppr - rc = %lx\n", rc); 49 } 50 51 static inline void icp_hv_set_qirr(int n_cpu , u8 value) 52 { 53 long rc = plpar_hcall_norets(H_IPI, get_hard_smp_processor_id(n_cpu), 54 value); 55 if (rc != H_SUCCESS) 56 panic("bad return code qirr - rc = %lx\n", rc); 57 } 58 59 static void icp_hv_eoi(struct irq_data *d) 60 { 61 unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); 62 63 iosync(); 64 icp_hv_set_xirr((xics_pop_cppr() << 24) | hw_irq); 65 } 66 67 static void icp_hv_teardown_cpu(void) 68 { 69 int cpu = smp_processor_id(); 70 71 /* Clear any pending IPI */ 72 icp_hv_set_qirr(cpu, 0xff); 73 } 74 75 static void icp_hv_flush_ipi(void) 76 { 77 /* We take the ipi irq but and never return so we 78 * need to EOI the IPI, but want to leave our priority 0 79 * 80 * should we check all the other interrupts too? 81 * should we be flagging idle loop instead? 82 * or creating some task to be scheduled? 83 */ 84 85 icp_hv_set_xirr((0x00 << 24) | XICS_IPI); 86 } 87 88 static unsigned int icp_hv_get_irq(void) 89 { 90 unsigned int xirr = icp_hv_get_xirr(xics_cppr_top()); 91 unsigned int vec = xirr & 0x00ffffff; 92 unsigned int irq; 93 94 if (vec == XICS_IRQ_SPURIOUS) 95 return NO_IRQ; 96 97 irq = irq_radix_revmap_lookup(xics_host, vec); 98 if (likely(irq != NO_IRQ)) { 99 xics_push_cppr(vec); 100 return irq; 101 } 102 103 /* We don't have a linux mapping, so have rtas mask it. */ 104 xics_mask_unknown_vec(vec); 105 106 /* We might learn about it later, so EOI it */ 107 icp_hv_set_xirr(xirr); 108 109 return NO_IRQ; 110 } 111 112 static void icp_hv_set_cpu_priority(unsigned char cppr) 113 { 114 xics_set_base_cppr(cppr); 115 icp_hv_set_cppr(cppr); 116 iosync(); 117 } 118 119 #ifdef CONFIG_SMP 120 121 static void icp_hv_cause_ipi(int cpu, unsigned long data) 122 { 123 icp_hv_set_qirr(cpu, IPI_PRIORITY); 124 } 125 126 static irqreturn_t icp_hv_ipi_action(int irq, void *dev_id) 127 { 128 int cpu = smp_processor_id(); 129 130 icp_hv_set_qirr(cpu, 0xff); 131 132 return smp_ipi_demux(); 133 } 134 135 #endif /* CONFIG_SMP */ 136 137 static const struct icp_ops icp_hv_ops = { 138 .get_irq = icp_hv_get_irq, 139 .eoi = icp_hv_eoi, 140 .set_priority = icp_hv_set_cpu_priority, 141 .teardown_cpu = icp_hv_teardown_cpu, 142 .flush_ipi = icp_hv_flush_ipi, 143 #ifdef CONFIG_SMP 144 .ipi_action = icp_hv_ipi_action, 145 .cause_ipi = icp_hv_cause_ipi, 146 #endif 147 }; 148 149 int icp_hv_init(void) 150 { 151 struct device_node *np; 152 153 np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xicp"); 154 if (!np) 155 np = of_find_node_by_type(NULL, 156 "PowerPC-External-Interrupt-Presentation"); 157 if (!np) 158 return -ENODEV; 159 160 icp_ops = &icp_hv_ops; 161 162 return 0; 163 } 164 165