diff options
Diffstat (limited to 'arch/x86/kernel/apic/apic_noop.c')
-rw-r--r-- | arch/x86/kernel/apic/apic_noop.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/apic_noop.c b/arch/x86/kernel/apic/apic_noop.c new file mode 100644 index 0000000000..966d7cf10b --- /dev/null +++ b/arch/x86/kernel/apic/apic_noop.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * NOOP APIC driver. + * + * Does almost nothing and should be substituted by a real apic driver via + * probe routine. + * + * Though in case if apic is disabled (for some reason) we try + * to not uglify the caller's code and allow to call (some) apic routines + * like self-ipi, etc... + * + * FIXME: Remove this gunk. The above argument which was intentionally left + * in place is silly to begin with because none of the callbacks except for + * APIC::read/write() have a WARN_ON_ONCE() in them. Sigh... + */ +#include <linux/cpumask.h> +#include <linux/thread_info.h> + +#include <asm/apic.h> + +static void noop_send_IPI(int cpu, int vector) { } +static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { } +static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { } +static void noop_send_IPI_allbutself(int vector) { } +static void noop_send_IPI_all(int vector) { } +static void noop_send_IPI_self(int vector) { } +static void noop_apic_icr_write(u32 low, u32 id) { } +static int noop_wakeup_secondary_cpu(int apicid, unsigned long start_eip) { return -1; } +static u64 noop_apic_icr_read(void) { return 0; } +static int noop_phys_pkg_id(int cpuid_apic, int index_msb) { return 0; } +static unsigned int noop_get_apic_id(unsigned long x) { return 0; } +static void noop_apic_eoi(void) { } + +static u32 noop_apic_read(u32 reg) +{ + WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled); + return 0; +} + +static void noop_apic_write(u32 reg, u32 val) +{ + WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !apic_is_disabled); +} + +struct apic apic_noop __ro_after_init = { + .name = "noop", + + .delivery_mode = APIC_DELIVERY_MODE_FIXED, + .dest_mode_logical = true, + + .disable_esr = 0, + + .check_apicid_used = default_check_apicid_used, + .ioapic_phys_id_map = default_ioapic_phys_id_map, + .cpu_present_to_apicid = default_cpu_present_to_apicid, + + .phys_pkg_id = noop_phys_pkg_id, + + .max_apic_id = 0xFE, + .get_apic_id = noop_get_apic_id, + + .calc_dest_apicid = apic_flat_calc_apicid, + + .send_IPI = noop_send_IPI, + .send_IPI_mask = noop_send_IPI_mask, + .send_IPI_mask_allbutself = noop_send_IPI_mask_allbutself, + .send_IPI_allbutself = noop_send_IPI_allbutself, + .send_IPI_all = noop_send_IPI_all, + .send_IPI_self = noop_send_IPI_self, + + .wakeup_secondary_cpu = noop_wakeup_secondary_cpu, + + .read = noop_apic_read, + .write = noop_apic_write, + .eoi = noop_apic_eoi, + .icr_read = noop_apic_icr_read, + .icr_write = noop_apic_icr_write, +}; |