arch/x86_64/kernel/genapic_flat.c

   1 /*
   2  * Copyright 2004 James Cleverdon, IBM.
   3  * Subject to the GNU Public License, v.2
   4  *
   5  * Flat 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 #include <linux/config.h>
  12 #include <linux/threads.h>
  13 #include <linux/cpumask.h>
  14 #include <linux/string.h>
  15 #include <linux/kernel.h>
  16 #include <linux/ctype.h>
  17 #include <linux/init.h>
  18 #include <asm/smp.h>
  19 #include <asm/ipi.h>
  20
  21
  22 static cpumask_t flat_target_cpus(void)
  23 {
  24         return cpu_online_map;
  25 }
  26
  27 /*
  28  * Set up the logical destination ID.
  29  *
  30  * Intel recommends to set DFR, LDR and TPR before enabling
  31  * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
  32  * document number 292116).  So here it goes...
  33  */
  34 static void flat_init_apic_ldr(void)
  35 {
  36         unsigned long val;
  37         unsigned long num, id;
  38
  39         num = smp_processor_id();
  40         id = 1UL << num;
  41         x86_cpu_to_log_apicid[num] = id;
  42         apic_write_around(APIC_DFR, APIC_DFR_FLAT);
  43         val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
  44         val |= SET_APIC_LOGICAL_ID(id);
  45         apic_write_around(APIC_LDR, val);
  46 }
  47
  48 static void flat_send_IPI_allbutself(int vector)
  49 {
  50         /*
  51          * if there are no other CPUs in the system then
  52          * we get an APIC send error if we try to broadcast.
  53          * thus we have to avoid sending IPIs in this case.
  54          */
  55         if (num_online_cpus() > 1)
  56                 __send_IPI_shortcut(APIC_DEST_ALLBUT, vector, APIC_DEST_LOGICAL);
  57 }
  58
  59 static void flat_send_IPI_all(int vector)
  60 {
  61         __send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL);
  62 }
  63
  64 static void flat_send_IPI_mask(cpumask_t cpumask, int vector)
  65 {
  66         unsigned long mask = cpus_addr(cpumask)[0];
  67         unsigned long cfg;
  68         unsigned long flags;
  69
  70         local_save_flags(flags);
  71         local_irq_disable();
  72
  73         /*
  74          * Wait for idle.
  75          */
  76         apic_wait_icr_idle();
  77
  78         /*
  79          * prepare target chip field
  80          */
  81         cfg = __prepare_ICR2(mask);
  82         apic_write_around(APIC_ICR2, cfg);
  83
  84         /*
  85          * program the ICR
  86          */
  87         cfg = __prepare_ICR(0, vector, APIC_DEST_LOGICAL);
  88
  89         /*
  90          * Send the IPI. The write to APIC_ICR fires this off.
  91          */
  92         apic_write_around(APIC_ICR, cfg);
  93         local_irq_restore(flags);
  94 }
  95
  96 static int flat_apic_id_registered(void)
  97 {
  98         return physid_isset(GET_APIC_ID(apic_read(APIC_ID)), phys_cpu_present_map);
  99 }
 100
 101 static unsigned int flat_cpu_mask_to_apicid(cpumask_t cpumask)
 102 {
 103         return cpus_addr(cpumask)[0] & APIC_ALL_CPUS;
 104 }
 105
 106 static unsigned int phys_pkg_id(int index_msb)
 107 {
 108         u32 ebx;
 109
 110         ebx = cpuid_ebx(1);
 111         return ((ebx >> 24) & 0xFF) >> index_msb;
 112 }
 113
 114 struct genapic apic_flat =  {
 115         .name = "flat",
 116         .int_delivery_mode = dest_LowestPrio,
 117         .int_dest_mode = (APIC_DEST_LOGICAL != 0),
 118         .int_delivery_dest = APIC_DEST_LOGICAL | APIC_DM_LOWEST,
 119         .target_cpus = flat_target_cpus,
 120         .apic_id_registered = flat_apic_id_registered,
 121         .init_apic_ldr = flat_init_apic_ldr,
 122         .send_IPI_all = flat_send_IPI_all,
 123         .send_IPI_allbutself = flat_send_IPI_allbutself,
 124         .send_IPI_mask = flat_send_IPI_mask,
 125         .cpu_mask_to_apicid = flat_cpu_mask_to_apicid,
 126         .phys_pkg_id = phys_pkg_id,
 127 };