1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 29844ab11SCyrill Gorcunov /* 39844ab11SCyrill Gorcunov * NOOP APIC driver. 49844ab11SCyrill Gorcunov * 59844ab11SCyrill Gorcunov * Does almost nothing and should be substituted by a real apic driver via 69844ab11SCyrill Gorcunov * probe routine. 79844ab11SCyrill Gorcunov * 89844ab11SCyrill Gorcunov * Though in case if apic is disabled (for some reason) we try 99844ab11SCyrill Gorcunov * to not uglify the caller's code and allow to call (some) apic routines 10f88f2b4fSCyrill Gorcunov * like self-ipi, etc... 119844ab11SCyrill Gorcunov */ 129844ab11SCyrill Gorcunov #include <linux/cpumask.h> 130cd39f46SPeter Zijlstra #include <linux/thread_info.h> 14521b82feSThomas Gleixner 159844ab11SCyrill Gorcunov #include <asm/apic.h> 169844ab11SCyrill Gorcunov 174727da2eSThomas Gleixner static void noop_send_IPI(int cpu, int vector) { } 18f88f2b4fSCyrill Gorcunov static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { } 19f88f2b4fSCyrill Gorcunov static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { } 20f88f2b4fSCyrill Gorcunov static void noop_send_IPI_allbutself(int vector) { } 21f88f2b4fSCyrill Gorcunov static void noop_send_IPI_all(int vector) { } 22f88f2b4fSCyrill Gorcunov static void noop_send_IPI_self(int vector) { } 23f88f2b4fSCyrill Gorcunov static void noop_apic_icr_write(u32 low, u32 id) { } 24f88f2b4fSCyrill Gorcunov 25f88f2b4fSCyrill Gorcunov static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip) 269844ab11SCyrill Gorcunov { 27f88f2b4fSCyrill Gorcunov return -1; 289844ab11SCyrill Gorcunov } 299844ab11SCyrill Gorcunov 30f88f2b4fSCyrill Gorcunov static u64 noop_apic_icr_read(void) 31f88f2b4fSCyrill Gorcunov { 32f88f2b4fSCyrill Gorcunov return 0; 33f88f2b4fSCyrill Gorcunov } 34f88f2b4fSCyrill Gorcunov 35f88f2b4fSCyrill Gorcunov static int noop_phys_pkg_id(int cpuid_apic, int index_msb) 36f88f2b4fSCyrill Gorcunov { 37f88f2b4fSCyrill Gorcunov return 0; 38f88f2b4fSCyrill Gorcunov } 39f88f2b4fSCyrill Gorcunov 40f88f2b4fSCyrill Gorcunov static unsigned int noop_get_apic_id(unsigned long x) 41f88f2b4fSCyrill Gorcunov { 42f88f2b4fSCyrill Gorcunov return 0; 43f88f2b4fSCyrill Gorcunov } 449844ab11SCyrill Gorcunov 459844ab11SCyrill Gorcunov static int noop_probe(void) 469844ab11SCyrill Gorcunov { 47f88f2b4fSCyrill Gorcunov /* 48f88f2b4fSCyrill Gorcunov * NOOP apic should not ever be 49f88f2b4fSCyrill Gorcunov * enabled via probe routine 50f88f2b4fSCyrill Gorcunov */ 519844ab11SCyrill Gorcunov return 0; 529844ab11SCyrill Gorcunov } 539844ab11SCyrill Gorcunov 549844ab11SCyrill Gorcunov static u32 noop_apic_read(u32 reg) 559844ab11SCyrill Gorcunov { 5649062454SThomas Gleixner WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled); 579844ab11SCyrill Gorcunov return 0; 589844ab11SCyrill Gorcunov } 599844ab11SCyrill Gorcunov 6049062454SThomas Gleixner static void noop_apic_write(u32 reg, u32 val) 61f88f2b4fSCyrill Gorcunov { 6249062454SThomas Gleixner WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled); 63f88f2b4fSCyrill Gorcunov } 64f88f2b4fSCyrill Gorcunov 65404f6aacSKees Cook struct apic apic_noop __ro_after_init = { 669844ab11SCyrill Gorcunov .name = "noop", 679844ab11SCyrill Gorcunov .probe = noop_probe, 689844ab11SCyrill Gorcunov .acpi_madt_oem_check = NULL, 699844ab11SCyrill Gorcunov 70fa63030eSDaniel J Blueman .apic_id_valid = default_apic_id_valid, 719844ab11SCyrill Gorcunov 7272161299SThomas Gleixner .delivery_mode = APIC_DELIVERY_MODE_FIXED, 738c44963bSThomas Gleixner .dest_mode_logical = true, 749844ab11SCyrill Gorcunov 759844ab11SCyrill Gorcunov .disable_esr = 0, 76e57d04e5SThomas Gleixner 774c59f3e6SDavid Rientjes .check_apicid_used = default_check_apicid_used, 787abc0753SCyrill Gorcunov .ioapic_phys_id_map = default_ioapic_phys_id_map, 799844ab11SCyrill Gorcunov .cpu_present_to_apicid = default_cpu_present_to_apicid, 809844ab11SCyrill Gorcunov 81f88f2b4fSCyrill Gorcunov .phys_pkg_id = noop_phys_pkg_id, 829844ab11SCyrill Gorcunov 83*d92e5e7cSThomas Gleixner .max_apic_id = 0xFE, 849844ab11SCyrill Gorcunov .get_apic_id = noop_get_apic_id, 859844ab11SCyrill Gorcunov .set_apic_id = NULL, 869844ab11SCyrill Gorcunov 879f9e3bb1SThomas Gleixner .calc_dest_apicid = apic_flat_calc_apicid, 889844ab11SCyrill Gorcunov 894727da2eSThomas Gleixner .send_IPI = noop_send_IPI, 909844ab11SCyrill Gorcunov .send_IPI_mask = noop_send_IPI_mask, 919844ab11SCyrill Gorcunov .send_IPI_mask_allbutself = noop_send_IPI_mask_allbutself, 929844ab11SCyrill Gorcunov .send_IPI_allbutself = noop_send_IPI_allbutself, 939844ab11SCyrill Gorcunov .send_IPI_all = noop_send_IPI_all, 949844ab11SCyrill Gorcunov .send_IPI_self = noop_send_IPI_self, 959844ab11SCyrill Gorcunov 969844ab11SCyrill Gorcunov .wakeup_secondary_cpu = noop_wakeup_secondary_cpu, 979844ab11SCyrill Gorcunov 989844ab11SCyrill Gorcunov .read = noop_apic_read, 999844ab11SCyrill Gorcunov .write = noop_apic_write, 1002a43195dSMichael S. Tsirkin .eoi_write = noop_apic_write, 1019844ab11SCyrill Gorcunov .icr_read = noop_apic_icr_read, 1029844ab11SCyrill Gorcunov .icr_write = noop_apic_icr_write, 1039844ab11SCyrill Gorcunov }; 104