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/init.h> 19 #include <linux/errno.h> 20 #include <asm/fixmap.h> 21 #include <asm/mpspec.h> 22 #include <asm/apicdef.h> 23 #include <asm/apic.h> 24 #include <asm/setup.h> 25 26 #include <linux/smp.h> 27 #include <asm/ipi.h> 28 29 #include <linux/interrupt.h> 30 #include <asm/acpi.h> 31 #include <asm/e820.h> 32 33 static void noop_init_apic_ldr(void) { } 34 static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { } 35 static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { } 36 static void noop_send_IPI_allbutself(int vector) { } 37 static void noop_send_IPI_all(int vector) { } 38 static void noop_send_IPI_self(int vector) { } 39 static void noop_apic_wait_icr_idle(void) { } 40 static void noop_apic_icr_write(u32 low, u32 id) { } 41 42 static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip) 43 { 44 return -1; 45 } 46 47 static u32 noop_safe_apic_wait_icr_idle(void) 48 { 49 return 0; 50 } 51 52 static u64 noop_apic_icr_read(void) 53 { 54 return 0; 55 } 56 57 static int noop_phys_pkg_id(int cpuid_apic, int index_msb) 58 { 59 return 0; 60 } 61 62 static unsigned int noop_get_apic_id(unsigned long x) 63 { 64 return 0; 65 } 66 67 static int noop_probe(void) 68 { 69 /* 70 * NOOP apic should not ever be 71 * enabled via probe routine 72 */ 73 return 0; 74 } 75 76 static int noop_apic_id_registered(void) 77 { 78 /* 79 * if we would be really "pedantic" 80 * we should pass read_apic_id() here 81 * but since NOOP suppose APIC ID = 0 82 * lets save a few cycles 83 */ 84 return physid_isset(0, phys_cpu_present_map); 85 } 86 87 static const struct cpumask *noop_target_cpus(void) 88 { 89 /* only BSP here */ 90 return cpumask_of(0); 91 } 92 93 static unsigned long noop_check_apicid_used(physid_mask_t *map, int apicid) 94 { 95 return physid_isset(apicid, *map); 96 } 97 98 static unsigned long noop_check_apicid_present(int bit) 99 { 100 return physid_isset(bit, phys_cpu_present_map); 101 } 102 103 static void noop_vector_allocation_domain(int cpu, struct cpumask *retmask) 104 { 105 if (cpu != 0) 106 pr_warning("APIC: Vector allocated for non-BSP cpu\n"); 107 cpumask_clear(retmask); 108 cpumask_set_cpu(cpu, retmask); 109 } 110 111 static u32 noop_apic_read(u32 reg) 112 { 113 WARN_ON_ONCE((cpu_has_apic && !disable_apic)); 114 return 0; 115 } 116 117 static void noop_apic_write(u32 reg, u32 v) 118 { 119 WARN_ON_ONCE(cpu_has_apic && !disable_apic); 120 } 121 122 #ifdef CONFIG_X86_32 123 static int noop_x86_32_numa_cpu_node(int cpu) 124 { 125 /* we're always on node 0 */ 126 return 0; 127 } 128 #endif 129 130 struct apic apic_noop = { 131 .name = "noop", 132 .probe = noop_probe, 133 .acpi_madt_oem_check = NULL, 134 135 .apic_id_registered = noop_apic_id_registered, 136 137 .irq_delivery_mode = dest_LowestPrio, 138 /* logical delivery broadcast to all CPUs: */ 139 .irq_dest_mode = 1, 140 141 .target_cpus = noop_target_cpus, 142 .disable_esr = 0, 143 .dest_logical = APIC_DEST_LOGICAL, 144 .check_apicid_used = noop_check_apicid_used, 145 .check_apicid_present = noop_check_apicid_present, 146 147 .vector_allocation_domain = noop_vector_allocation_domain, 148 .init_apic_ldr = noop_init_apic_ldr, 149 150 .ioapic_phys_id_map = default_ioapic_phys_id_map, 151 .setup_apic_routing = NULL, 152 .multi_timer_check = NULL, 153 154 .cpu_present_to_apicid = default_cpu_present_to_apicid, 155 .apicid_to_cpu_present = physid_set_mask_of_physid, 156 157 .setup_portio_remap = NULL, 158 .check_phys_apicid_present = default_check_phys_apicid_present, 159 .enable_apic_mode = NULL, 160 161 .phys_pkg_id = noop_phys_pkg_id, 162 163 .mps_oem_check = NULL, 164 165 .get_apic_id = noop_get_apic_id, 166 .set_apic_id = NULL, 167 .apic_id_mask = 0x0F << 24, 168 169 .cpu_mask_to_apicid = default_cpu_mask_to_apicid, 170 .cpu_mask_to_apicid_and = default_cpu_mask_to_apicid_and, 171 172 .send_IPI_mask = noop_send_IPI_mask, 173 .send_IPI_mask_allbutself = noop_send_IPI_mask_allbutself, 174 .send_IPI_allbutself = noop_send_IPI_allbutself, 175 .send_IPI_all = noop_send_IPI_all, 176 .send_IPI_self = noop_send_IPI_self, 177 178 .wakeup_secondary_cpu = noop_wakeup_secondary_cpu, 179 180 /* should be safe */ 181 .trampoline_phys_low = DEFAULT_TRAMPOLINE_PHYS_LOW, 182 .trampoline_phys_high = DEFAULT_TRAMPOLINE_PHYS_HIGH, 183 184 .wait_for_init_deassert = NULL, 185 186 .smp_callin_clear_local_apic = NULL, 187 .inquire_remote_apic = NULL, 188 189 .read = noop_apic_read, 190 .write = noop_apic_write, 191 .icr_read = noop_apic_icr_read, 192 .icr_write = noop_apic_icr_write, 193 .wait_icr_idle = noop_apic_wait_icr_idle, 194 .safe_wait_icr_idle = noop_safe_apic_wait_icr_idle, 195 196 #ifdef CONFIG_X86_32 197 .x86_32_early_logical_apicid = noop_x86_32_early_logical_apicid, 198 .x86_32_numa_cpu_node = noop_x86_32_numa_cpu_node, 199 #endif 200 }; 201