~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/powerpc/sysdev/xics/icp-opal.c

Version: ~ [ linux-5.4-rc3 ] ~ [ linux-5.3.6 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.79 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.149 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.196 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.196 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.75 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Copyright 2016 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 #include <linux/types.h>
 10 #include <linux/kernel.h>
 11 #include <linux/irq.h>
 12 #include <linux/smp.h>
 13 #include <linux/interrupt.h>
 14 #include <linux/cpu.h>
 15 #include <linux/of.h>
 16 
 17 #include <asm/smp.h>
 18 #include <asm/irq.h>
 19 #include <asm/errno.h>
 20 #include <asm/xics.h>
 21 #include <asm/io.h>
 22 #include <asm/opal.h>
 23 #include <asm/kvm_ppc.h>
 24 
 25 static void icp_opal_teardown_cpu(void)
 26 {
 27         int hw_cpu = hard_smp_processor_id();
 28 
 29         /* Clear any pending IPI */
 30         opal_int_set_mfrr(hw_cpu, 0xff);
 31 }
 32 
 33 static void icp_opal_flush_ipi(void)
 34 {
 35         /*
 36          * We take the ipi irq but and never return so we need to EOI the IPI,
 37          * but want to leave our priority 0.
 38          *
 39          * Should we check all the other interrupts too?
 40          * Should we be flagging idle loop instead?
 41          * Or creating some task to be scheduled?
 42          */
 43         if (opal_int_eoi((0x00 << 24) | XICS_IPI) > 0)
 44                 force_external_irq_replay();
 45 }
 46 
 47 static unsigned int icp_opal_get_xirr(void)
 48 {
 49         unsigned int kvm_xirr;
 50         __be32 hw_xirr;
 51         int64_t rc;
 52 
 53         /* Handle an interrupt latched by KVM first */
 54         kvm_xirr = kvmppc_get_xics_latch();
 55         if (kvm_xirr)
 56                 return kvm_xirr;
 57 
 58         /* Then ask OPAL */
 59         rc = opal_int_get_xirr(&hw_xirr, false);
 60         if (rc < 0)
 61                 return 0;
 62         return be32_to_cpu(hw_xirr);
 63 }
 64 
 65 static unsigned int icp_opal_get_irq(void)
 66 {
 67         unsigned int xirr;
 68         unsigned int vec;
 69         unsigned int irq;
 70 
 71         xirr = icp_opal_get_xirr();
 72         vec = xirr & 0x00ffffff;
 73         if (vec == XICS_IRQ_SPURIOUS)
 74                 return 0;
 75 
 76         irq = irq_find_mapping(xics_host, vec);
 77         if (likely(irq)) {
 78                 xics_push_cppr(vec);
 79                 return irq;
 80         }
 81 
 82         /* We don't have a linux mapping, so have rtas mask it. */
 83         xics_mask_unknown_vec(vec);
 84 
 85         /* We might learn about it later, so EOI it */
 86         if (opal_int_eoi(xirr) > 0)
 87                 force_external_irq_replay();
 88 
 89         return 0;
 90 }
 91 
 92 static void icp_opal_set_cpu_priority(unsigned char cppr)
 93 {
 94         /*
 95          * Here be dragons. The caller has asked to allow only IPI's and not
 96          * external interrupts. But OPAL XIVE doesn't support that. So instead
 97          * of allowing no interrupts allow all. That's still not right, but
 98          * currently the only caller who does this is xics_migrate_irqs_away()
 99          * and it works in that case.
100          */
101         if (cppr >= DEFAULT_PRIORITY)
102                 cppr = LOWEST_PRIORITY;
103 
104         xics_set_base_cppr(cppr);
105         opal_int_set_cppr(cppr);
106         iosync();
107 }
108 
109 static void icp_opal_eoi(struct irq_data *d)
110 {
111         unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
112         int64_t rc;
113 
114         iosync();
115         rc = opal_int_eoi((xics_pop_cppr() << 24) | hw_irq);
116 
117         /*
118          * EOI tells us whether there are more interrupts to fetch.
119          *
120          * Some HW implementations might not be able to send us another
121          * external interrupt in that case, so we force a replay.
122          */
123         if (rc > 0)
124                 force_external_irq_replay();
125 }
126 
127 #ifdef CONFIG_SMP
128 
129 static void icp_opal_cause_ipi(int cpu)
130 {
131         int hw_cpu = get_hard_smp_processor_id(cpu);
132 
133         kvmppc_set_host_ipi(cpu, 1);
134         opal_int_set_mfrr(hw_cpu, IPI_PRIORITY);
135 }
136 
137 static irqreturn_t icp_opal_ipi_action(int irq, void *dev_id)
138 {
139         int cpu = smp_processor_id();
140 
141         kvmppc_set_host_ipi(cpu, 0);
142         opal_int_set_mfrr(get_hard_smp_processor_id(cpu), 0xff);
143 
144         return smp_ipi_demux();
145 }
146 
147 /*
148  * Called when an interrupt is received on an off-line CPU to
149  * clear the interrupt, so that the CPU can go back to nap mode.
150  */
151 void icp_opal_flush_interrupt(void)
152 {
153         unsigned int xirr;
154         unsigned int vec;
155 
156         do {
157                 xirr = icp_opal_get_xirr();
158                 vec = xirr & 0x00ffffff;
159                 if (vec == XICS_IRQ_SPURIOUS)
160                         break;
161                 if (vec == XICS_IPI) {
162                         /* Clear pending IPI */
163                         int cpu = smp_processor_id();
164                         kvmppc_set_host_ipi(cpu, 0);
165                         opal_int_set_mfrr(get_hard_smp_processor_id(cpu), 0xff);
166                 } else {
167                         pr_err("XICS: hw interrupt 0x%x to offline cpu, "
168                                "disabling\n", vec);
169                         xics_mask_unknown_vec(vec);
170                 }
171 
172                 /* EOI the interrupt */
173         } while (opal_int_eoi(xirr) > 0);
174 }
175 
176 #endif /* CONFIG_SMP */
177 
178 static const struct icp_ops icp_opal_ops = {
179         .get_irq        = icp_opal_get_irq,
180         .eoi            = icp_opal_eoi,
181         .set_priority   = icp_opal_set_cpu_priority,
182         .teardown_cpu   = icp_opal_teardown_cpu,
183         .flush_ipi      = icp_opal_flush_ipi,
184 #ifdef CONFIG_SMP
185         .ipi_action     = icp_opal_ipi_action,
186         .cause_ipi      = icp_opal_cause_ipi,
187 #endif
188 };
189 
190 int icp_opal_init(void)
191 {
192         struct device_node *np;
193 
194         np = of_find_compatible_node(NULL, NULL, "ibm,opal-intc");
195         if (!np)
196                 return -ENODEV;
197 
198         icp_ops = &icp_opal_ops;
199 
200         printk("XICS: Using OPAL ICP fallbacks\n");
201 
202         return 0;
203 }
204 
205 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp