Quelle  probe_32.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Default generic APIC driver. This handles up to 8 CPUs.
 *
 * Copyright 2003 Andi Kleen, SuSE Labs.
 *
 * Generic x86 APIC driver probe layer.
 */
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/smp.h>

#include <xen/xen.h>

#include <asm/io_apic.h>
#include <asm/apic.h>
#include <asm/acpi.h>

#include "local.h"

static u32 default_get_apic_id(u32 x)
{
 unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));

 if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
  return (x >> 24) & 0xFF;
 else
  return (x >> 24) & 0x0F;
}

/* should be called last. */
static int probe_default(void)
{
 return 1;
}

static struct apic apic_default __ro_after_init = {

 .name    = "default",
 .probe    = probe_default,

 .dest_mode_logical  = true,

 .disable_esr   = 0,

 .init_apic_ldr   = default_init_apic_ldr,
 .cpu_present_to_apicid  = default_cpu_present_to_apicid,

 .max_apic_id   = 0xFE,
 .get_apic_id   = default_get_apic_id,

 .calc_dest_apicid  = apic_flat_calc_apicid,

 .send_IPI   = default_send_IPI_single,
 .send_IPI_mask   = default_send_IPI_mask_logical,
 .send_IPI_mask_allbutself = default_send_IPI_mask_allbutself_logical,
 .send_IPI_allbutself  = default_send_IPI_allbutself,
 .send_IPI_all   = default_send_IPI_all,
 .send_IPI_self   = default_send_IPI_self,

 .read    = native_apic_mem_read,
 .write    = native_apic_mem_write,
 .eoi    = native_apic_mem_eoi,
 .icr_read   = native_apic_icr_read,
 .icr_write   = native_apic_icr_write,
 .wait_icr_idle   = apic_mem_wait_icr_idle,
 .safe_wait_icr_idle  = apic_mem_wait_icr_idle_timeout,
};

apic_driver(apic_default);

struct apic *apic __ro_after_init = &apic_default;
EXPORT_SYMBOL_GPL(apic);

static int cmdline_apic __initdata;
static int __init parse_apic(char *arg)
{
 struct apic **drv;

 if (!arg)
  return -EINVAL;

 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
  if (!strcmp((*drv)->name, arg)) {
   apic_install_driver(*drv);
   cmdline_apic = 1;
   return 0;
  }
 }

 /* Parsed again by __setup for debug/verbose */
 return 0;
}
early_param("apic", parse_apic);

void __init x86_32_probe_apic(void)
{
 if (!cmdline_apic) {
  struct apic **drv;

  for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
   if ((*drv)->probe()) {
    apic_install_driver(*drv);
    break;
   }
  }
  /* Not visible without early console */
  if (drv == __apicdrivers_end)
   panic("Didn't find an APIC driver");
 }
}