arch/x86_64/kernel/genapic_xen.c

   1 /*
   2  * Copyright 2004 James Cleverdon, IBM.
   3  * Subject to the GNU Public License, v.2
   4  *
   5  * Xen APIC subarch code.  Maximum 8 CPUs, logical delivery.
   6  *
   7  * Hacked for x86-64 by James Cleverdon from i386 architecture code by
   8  * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
   9  * James Cleverdon.
  10  *
  11  * Hacked to pieces for Xen by Chris Wright.
  12  */
  13 #include <linux/threads.h>
  14 #include <linux/cpumask.h>
  15 #include <linux/string.h>
  16 #include <linux/kernel.h>
  17 #include <linux/ctype.h>
  18 #include <linux/init.h>
  19 #ifdef CONFIG_XEN_PRIVILEGED_GUEST
  20 #include <asm/smp.h>
  21 #include <asm/ipi.h>
  22 #else
  23 #include <asm/apic.h>
  24 #include <asm/apicdef.h>
  25 #include <asm/genapic.h>
  26 #endif
  27 #include <xen/evtchn.h>
  28
  29 DECLARE_PER_CPU(int, ipi_to_irq[NR_IPIS]);
  30
  31 static inline void __send_IPI_one(unsigned int cpu, int vector)
  32 {
  33         int irq = per_cpu(ipi_to_irq, cpu)[vector];
  34         BUG_ON(irq < 0);
  35         notify_remote_via_irq(irq);
  36 }
  37
  38 void xen_send_IPI_shortcut(unsigned int shortcut, int vector, unsigned int dest)
  39 {
  40         int cpu;
  41
  42         switch (shortcut) {
  43         case APIC_DEST_SELF:
  44                 __send_IPI_one(smp_processor_id(), vector);
  45                 break;
  46         case APIC_DEST_ALLBUT:
  47                 for (cpu = 0; cpu < NR_CPUS; ++cpu) {
  48                         if (cpu == smp_processor_id())
  49                                 continue;
  50                         if (cpu_isset(cpu, cpu_online_map)) {
  51                                 __send_IPI_one(cpu, vector);
  52                         }
  53                 }
  54                 break;
  55         case APIC_DEST_ALLINC:
  56                 for (cpu = 0; cpu < NR_CPUS; ++cpu) {
  57                         if (cpu_isset(cpu, cpu_online_map)) {
  58                                 __send_IPI_one(cpu, vector);
  59                         }
  60                 }
  61                 break;
  62         default:
  63                 printk("XXXXXX __send_IPI_shortcut %08x vector %d\n", shortcut,
  64                        vector);
  65                 break;
  66         }
  67 }
  68
  69 static cpumask_t xen_target_cpus(void)
  70 {
  71         return cpu_online_map;
  72 }
  73
  74 static cpumask_t xen_vector_allocation_domain(int cpu)
  75 {
  76         /* Careful. Some cpus do not strictly honor the set of cpus
  77          * specified in the interrupt destination when using lowest
  78          * priority interrupt delivery mode.
  79          *
  80          * In particular there was a hyperthreading cpu observed to
  81          * deliver interrupts to the wrong hyperthread when only one
  82          * hyperthread was specified in the interrupt desitination.
  83          */
  84         cpumask_t domain = { { [0] = APIC_ALL_CPUS, } };
  85         return domain;
  86 }
  87
  88 /*
  89  * Set up the logical destination ID.
  90  * Do nothing, not called now.
  91  */
  92 static void xen_init_apic_ldr(void)
  93 {
  94         Dprintk("%s\n", __FUNCTION__);
  95         return;
  96 }
  97
  98 static void xen_send_IPI_mask(cpumask_t cpumask, int vector)
  99 {
 100         unsigned long mask = cpus_addr(cpumask)[0];
 101         unsigned int cpu;
 102         unsigned long flags;
 103
 104         Dprintk("%s\n", __FUNCTION__);
 105         local_irq_save(flags);
 106         WARN_ON(mask & ~cpus_addr(cpu_online_map)[0]);
 107
 108         for (cpu = 0; cpu < NR_CPUS; ++cpu) {
 109                 if (cpu_isset(cpu, cpumask)) {
 110                         __send_IPI_one(cpu, vector);
 111                 }
 112         }
 113         local_irq_restore(flags);
 114 }
 115
 116 static void xen_send_IPI_allbutself(int vector)
 117 {
 118 #ifdef  CONFIG_HOTPLUG_CPU
 119         int hotplug = 1;
 120 #else
 121         int hotplug = 0;
 122 #endif
 123         /*
 124          * if there are no other CPUs in the system then
 125          * we get an APIC send error if we try to broadcast.
 126          * thus we have to avoid sending IPIs in this case.
 127          */
 128         Dprintk("%s\n", __FUNCTION__);
 129         if (hotplug || vector == NMI_VECTOR) {
 130                 cpumask_t allbutme = cpu_online_map;
 131
 132                 cpu_clear(smp_processor_id(), allbutme);
 133
 134                 if (!cpus_empty(allbutme))
 135                         xen_send_IPI_mask(allbutme, vector);
 136         } else if (num_online_cpus() > 1) {
 137                 xen_send_IPI_shortcut(APIC_DEST_ALLBUT, vector, APIC_DEST_LOGICAL);
 138         }
 139 }
 140
 141 static void xen_send_IPI_all(int vector)
 142 {
 143         Dprintk("%s\n", __FUNCTION__);
 144         if (vector == NMI_VECTOR)
 145                 xen_send_IPI_mask(cpu_online_map, vector);
 146         else
 147                 xen_send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL);
 148 }
 149
 150 #ifdef CONFIG_XEN_PRIVILEGED_GUEST
 151 static int xen_apic_id_registered(void)
 152 {
 153         /* better be set */
 154         Dprintk("%s\n", __FUNCTION__);
 155         return physid_isset(smp_processor_id(), phys_cpu_present_map);
 156 }
 157 #endif
 158
 159 static unsigned int xen_cpu_mask_to_apicid(cpumask_t cpumask)
 160 {
 161         Dprintk("%s\n", __FUNCTION__);
 162         return cpus_addr(cpumask)[0] & APIC_ALL_CPUS;
 163 }
 164
 165 static unsigned int phys_pkg_id(int index_msb)
 166 {
 167         int ebx;
 168         Dprintk("%s\n", __FUNCTION__);
 169         ebx = cpuid_ebx(1);
 170         return ((ebx >> 24) & 0xFF) >> index_msb;
 171 }
 172
 173 struct genapic apic_xen =  {
 174         .name = "xen",
 175 #ifdef CONFIG_XEN_PRIVILEGED_GUEST
 176         .int_delivery_mode = dest_LowestPrio,
 177 #endif
 178         .int_dest_mode = (APIC_DEST_LOGICAL != 0),
 179         .target_cpus = xen_target_cpus,
 180         .vector_allocation_domain = xen_vector_allocation_domain,
 181 #ifdef CONFIG_XEN_PRIVILEGED_GUEST
 182         .apic_id_registered = xen_apic_id_registered,
 183 #endif
 184         .init_apic_ldr = xen_init_apic_ldr,
 185         .send_IPI_all = xen_send_IPI_all,
 186         .send_IPI_allbutself = xen_send_IPI_allbutself,
 187         .send_IPI_mask = xen_send_IPI_mask,
 188         .cpu_mask_to_apicid = xen_cpu_mask_to_apicid,
 189         .phys_pkg_id = phys_pkg_id,
 190 };