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