arch/x86/kernel/apic/init.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #define pr_fmt(fmt) "APIC: " fmt
   3
   4 #include <asm/apic.h>
   5
   6 #include "local.h"
   7
   8 /*
   9  * Use DEFINE_STATIC_CALL_NULL() to avoid having to provide stub functions
  10  * for each callback. The callbacks are setup during boot and all except
  11  * wait_icr_idle() must be initialized before usage. The IPI wrappers
  12  * use static_call() and not static_call_cond() to catch any fails.
  13  */
  14 #define DEFINE_APIC_CALL(__cb)                                          \
  15         DEFINE_STATIC_CALL_NULL(apic_call_##__cb, *apic->__cb)
  16
  17 DEFINE_APIC_CALL(eoi);
  18 DEFINE_APIC_CALL(native_eoi);
  19 DEFINE_APIC_CALL(icr_read);
  20 DEFINE_APIC_CALL(icr_write);
  21 DEFINE_APIC_CALL(read);
  22 DEFINE_APIC_CALL(send_IPI);
  23 DEFINE_APIC_CALL(send_IPI_mask);
  24 DEFINE_APIC_CALL(send_IPI_mask_allbutself);
  25 DEFINE_APIC_CALL(send_IPI_allbutself);
  26 DEFINE_APIC_CALL(send_IPI_all);
  27 DEFINE_APIC_CALL(send_IPI_self);
  28 DEFINE_APIC_CALL(wait_icr_idle);
  29 DEFINE_APIC_CALL(wakeup_secondary_cpu);
  30 DEFINE_APIC_CALL(wakeup_secondary_cpu_64);
  31 DEFINE_APIC_CALL(write);
  32
  33 EXPORT_STATIC_CALL_TRAMP_GPL(apic_call_send_IPI_mask);
  34 EXPORT_STATIC_CALL_TRAMP_GPL(apic_call_send_IPI_self);
  35
  36 /* The container for function call overrides */
  37 struct apic_override __x86_apic_override __initdata;
  38
  39 #define apply_override(__cb)                                    \
  40         if (__x86_apic_override.__cb)                           \
  41                 apic->__cb = __x86_apic_override.__cb
  42
  43 static __init void restore_override_callbacks(void)
  44 {
  45         apply_override(eoi);
  46         apply_override(native_eoi);
  47         apply_override(write);
  48         apply_override(read);
  49         apply_override(send_IPI);
  50         apply_override(send_IPI_mask);
  51         apply_override(send_IPI_mask_allbutself);
  52         apply_override(send_IPI_allbutself);
  53         apply_override(send_IPI_all);
  54         apply_override(send_IPI_self);
  55         apply_override(icr_read);
  56         apply_override(icr_write);
  57         apply_override(wakeup_secondary_cpu);
  58         apply_override(wakeup_secondary_cpu_64);
  59 }
  60
  61 #define update_call(__cb)                                       \
  62         static_call_update(apic_call_##__cb, *apic->__cb)
  63
  64 static __init void update_static_calls(void)
  65 {
  66         update_call(eoi);
  67         update_call(native_eoi);
  68         update_call(write);
  69         update_call(read);
  70         update_call(send_IPI);
  71         update_call(send_IPI_mask);
  72         update_call(send_IPI_mask_allbutself);
  73         update_call(send_IPI_allbutself);
  74         update_call(send_IPI_all);
  75         update_call(send_IPI_self);
  76         update_call(icr_read);
  77         update_call(icr_write);
  78         update_call(wait_icr_idle);
  79         update_call(wakeup_secondary_cpu);
  80         update_call(wakeup_secondary_cpu_64);
  81 }
  82
  83 void __init apic_setup_apic_calls(void)
  84 {
  85         /* Ensure that the default APIC has native_eoi populated */
  86         apic->native_eoi = apic->eoi;
  87         update_static_calls();
  88         pr_info("Static calls initialized\n");
  89 }
  90
  91 void __init apic_install_driver(struct apic *driver)
  92 {
  93         if (apic == driver)
  94                 return;
  95
  96         apic = driver;
  97
  98         if (IS_ENABLED(CONFIG_X86_X2APIC) && apic->x2apic_set_max_apicid)
  99                 apic->max_apic_id = x2apic_max_apicid;
 100
 101         /* Copy the original eoi() callback as KVM/HyperV might overwrite it */
 102         if (!apic->native_eoi)
 103                 apic->native_eoi = apic->eoi;
 104
 105         /* Apply any already installed callback overrides */
 106         restore_override_callbacks();
 107         update_static_calls();
 108
 109         pr_info("Switched APIC routing to: %s\n", driver->name);
 110 }