arch/x86/kernel/apic/apic_noop.c

   1 /*
   2  * NOOP APIC driver.
   3  *
   4  * Does almost nothing and should be substituted by a real apic driver via
   5  * probe routine.
   6  *
   7  * Though in case if apic is disabled (for some reason) we try
   8  * to not uglify the caller's code and allow to call (some) apic routines
   9  * like self-ipi, etc...
  10  */
  11
  12 #include <linux/threads.h>
  13 #include <linux/cpumask.h>
  14 #include <linux/module.h>
  15 #include <linux/string.h>
  16 #include <linux/kernel.h>
  17 #include <linux/ctype.h>
  18 #include <linux/errno.h>
  19 #include <asm/fixmap.h>
  20 #include <asm/mpspec.h>
  21 #include <asm/apicdef.h>
  22 #include <asm/apic.h>
  23 #include <asm/setup.h>
  24
  25 #include <linux/smp.h>
  26 #include <asm/ipi.h>
  27
  28 #include <linux/interrupt.h>
  29 #include <asm/acpi.h>
  30 #include <asm/e820.h>
  31
  32 static void noop_init_apic_ldr(void) { }
  33 static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { }
  34 static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { }
  35 static void noop_send_IPI_allbutself(int vector) { }
  36 static void noop_send_IPI_all(int vector) { }
  37 static void noop_send_IPI_self(int vector) { }
  38 static void noop_apic_wait_icr_idle(void) { }
  39 static void noop_apic_icr_write(u32 low, u32 id) { }
  40
  41 static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip)
  42 {
  43         return -1;
  44 }
  45
  46 static u32 noop_safe_apic_wait_icr_idle(void)
  47 {
  48         return 0;
  49 }
  50
  51 static u64 noop_apic_icr_read(void)
  52 {
  53         return 0;
  54 }
  55
  56 static int noop_phys_pkg_id(int cpuid_apic, int index_msb)
  57 {
  58         return 0;
  59 }
  60
  61 static unsigned int noop_get_apic_id(unsigned long x)
  62 {
  63         return 0;
  64 }
  65
  66 static int noop_probe(void)
  67 {
  68         /*
  69          * NOOP apic should not ever be
  70          * enabled via probe routine
  71          */
  72         return 0;
  73 }
  74
  75 static int noop_apic_id_registered(void)
  76 {
  77         /*
  78          * if we would be really "pedantic"
  79          * we should pass read_apic_id() here
  80          * but since NOOP suppose APIC ID = 0
  81          * lets save a few cycles
  82          */
  83         return physid_isset(0, phys_cpu_present_map);
  84 }
  85
  86 static const struct cpumask *noop_target_cpus(void)
  87 {
  88         /* only BSP here */
  89         return cpumask_of(0);
  90 }
  91
  92 static unsigned long noop_check_apicid_used(physid_mask_t *map, int apicid)
  93 {
  94         return physid_isset(apicid, *map);
  95 }
  96
  97 static unsigned long noop_check_apicid_present(int bit)
  98 {
  99         return physid_isset(bit, phys_cpu_present_map);
 100 }
 101
 102 static void noop_vector_allocation_domain(int cpu, struct cpumask *retmask,
 103                                           const struct cpumask *mask)
 104 {
 105         if (cpu != 0)
 106                 pr_warning("APIC: Vector allocated for non-BSP cpu\n");
 107         cpumask_copy(retmask, cpumask_of(cpu));
 108 }
 109
 110 static u32 noop_apic_read(u32 reg)
 111 {
 112         WARN_ON_ONCE((cpu_has_apic && !disable_apic));
 113         return 0;
 114 }
 115
 116 static void noop_apic_write(u32 reg, u32 v)
 117 {
 118         WARN_ON_ONCE(cpu_has_apic && !disable_apic);
 119 }
 120
 121 struct apic apic_noop = {
 122         .name                           = "noop",
 123         .probe                          = noop_probe,
 124         .acpi_madt_oem_check            = NULL,
 125
 126         .apic_id_valid                  = default_apic_id_valid,
 127         .apic_id_registered             = noop_apic_id_registered,
 128
 129         .irq_delivery_mode              = dest_LowestPrio,
 130         /* logical delivery broadcast to all CPUs: */
 131         .irq_dest_mode                  = 1,
 132
 133         .target_cpus                    = noop_target_cpus,
 134         .disable_esr                    = 0,
 135         .dest_logical                   = APIC_DEST_LOGICAL,
 136         .check_apicid_used              = noop_check_apicid_used,
 137         .check_apicid_present           = noop_check_apicid_present,
 138
 139         .vector_allocation_domain       = noop_vector_allocation_domain,
 140         .init_apic_ldr                  = noop_init_apic_ldr,
 141
 142         .ioapic_phys_id_map             = default_ioapic_phys_id_map,
 143         .setup_apic_routing             = NULL,
 144         .multi_timer_check              = NULL,
 145
 146         .cpu_present_to_apicid          = default_cpu_present_to_apicid,
 147         .apicid_to_cpu_present          = physid_set_mask_of_physid,
 148
 149         .setup_portio_remap             = NULL,
 150         .check_phys_apicid_present      = default_check_phys_apicid_present,
 151         .enable_apic_mode               = NULL,
 152
 153         .phys_pkg_id                    = noop_phys_pkg_id,
 154
 155         .mps_oem_check                  = NULL,
 156
 157         .get_apic_id                    = noop_get_apic_id,
 158         .set_apic_id                    = NULL,
 159         .apic_id_mask                   = 0x0F << 24,
 160
 161         .cpu_mask_to_apicid_and         = flat_cpu_mask_to_apicid_and,
 162
 163         .send_IPI_mask                  = noop_send_IPI_mask,
 164         .send_IPI_mask_allbutself       = noop_send_IPI_mask_allbutself,
 165         .send_IPI_allbutself            = noop_send_IPI_allbutself,
 166         .send_IPI_all                   = noop_send_IPI_all,
 167         .send_IPI_self                  = noop_send_IPI_self,
 168
 169         .wakeup_secondary_cpu           = noop_wakeup_secondary_cpu,
 170
 171         /* should be safe */
 172         .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
 173         .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,
 174
 175         .wait_for_init_deassert         = NULL,
 176
 177         .smp_callin_clear_local_apic    = NULL,
 178         .inquire_remote_apic            = NULL,
 179
 180         .read                           = noop_apic_read,
 181         .write                          = noop_apic_write,
 182         .eoi_write                      = noop_apic_write,
 183         .icr_read                       = noop_apic_icr_read,
 184         .icr_write                      = noop_apic_icr_write,
 185         .wait_icr_idle                  = noop_apic_wait_icr_idle,
 186         .safe_wait_icr_idle             = noop_safe_apic_wait_icr_idle,
 187
 188 #ifdef CONFIG_X86_32
 189         .x86_32_early_logical_apicid    = noop_x86_32_early_logical_apicid,
 190 #endif
 191 };