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 void noop_vector_allocation_domain(int cpu, struct cpumask *retmask, 93 const struct cpumask *mask) 94 { 95 if (cpu != 0) 96 pr_warning("APIC: Vector allocated for non-BSP cpu\n"); 97 cpumask_copy(retmask, cpumask_of(cpu)); 98 } 99 100 static u32 noop_apic_read(u32 reg) 101 { 102 WARN_ON_ONCE((cpu_has_apic && !disable_apic)); 103 return 0; 104 } 105 106 static void noop_apic_write(u32 reg, u32 v) 107 { 108 WARN_ON_ONCE(cpu_has_apic && !disable_apic); 109 } 110 111 struct apic apic_noop = { 112 .name = "noop", 113 .probe = noop_probe, 114 .acpi_madt_oem_check = NULL, 115 116 .apic_id_valid = default_apic_id_valid, 117 .apic_id_registered = noop_apic_id_registered, 118 119 .irq_delivery_mode = dest_LowestPrio, 120 /* logical delivery broadcast to all CPUs: */ 121 .irq_dest_mode = 1, 122 123 .target_cpus = noop_target_cpus, 124 .disable_esr = 0, 125 .dest_logical = APIC_DEST_LOGICAL, 126 .check_apicid_used = default_check_apicid_used, 127 128 .vector_allocation_domain = noop_vector_allocation_domain, 129 .init_apic_ldr = noop_init_apic_ldr, 130 131 .ioapic_phys_id_map = default_ioapic_phys_id_map, 132 .setup_apic_routing = NULL, 133 134 .cpu_present_to_apicid = default_cpu_present_to_apicid, 135 .apicid_to_cpu_present = physid_set_mask_of_physid, 136 137 .check_phys_apicid_present = default_check_phys_apicid_present, 138 139 .phys_pkg_id = noop_phys_pkg_id, 140 141 .get_apic_id = noop_get_apic_id, 142 .set_apic_id = NULL, 143 .apic_id_mask = 0x0F << 24, 144 145 .cpu_mask_to_apicid_and = flat_cpu_mask_to_apicid_and, 146 147 .send_IPI_mask = noop_send_IPI_mask, 148 .send_IPI_mask_allbutself = noop_send_IPI_mask_allbutself, 149 .send_IPI_allbutself = noop_send_IPI_allbutself, 150 .send_IPI_all = noop_send_IPI_all, 151 .send_IPI_self = noop_send_IPI_self, 152 153 .wakeup_secondary_cpu = noop_wakeup_secondary_cpu, 154 155 .wait_for_init_deassert = false, 156 .inquire_remote_apic = NULL, 157 158 .read = noop_apic_read, 159 .write = noop_apic_write, 160 .eoi_write = noop_apic_write, 161 .icr_read = noop_apic_icr_read, 162 .icr_write = noop_apic_icr_write, 163 .wait_icr_idle = noop_apic_wait_icr_idle, 164 .safe_wait_icr_idle = noop_safe_apic_wait_icr_idle, 165 166 #ifdef CONFIG_X86_32 167 .x86_32_early_logical_apicid = noop_x86_32_early_logical_apicid, 168 #endif 169 }; 170