diff options
Diffstat (limited to 'arch/x86/kernel/apic/ipi.c')
| -rw-r--r-- | arch/x86/kernel/apic/ipi.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/ipi.c b/arch/x86/kernel/apic/ipi.c new file mode 100644 index 000000000..82f9244fe --- /dev/null +++ b/arch/x86/kernel/apic/ipi.c @@ -0,0 +1,244 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/cpumask.h> +#include <linux/interrupt.h> + +#include <linux/mm.h> +#include <linux/delay.h> +#include <linux/spinlock.h> +#include <linux/kernel_stat.h> +#include <linux/mc146818rtc.h> +#include <linux/cache.h> +#include <linux/cpu.h> + +#include <asm/smp.h> +#include <asm/mtrr.h> +#include <asm/tlbflush.h> +#include <asm/mmu_context.h> +#include <asm/apic.h> +#include <asm/proto.h> +#include <asm/ipi.h> + +void __default_send_IPI_shortcut(unsigned int shortcut, int vector, unsigned int dest) +{ + /* + * Subtle. In the case of the 'never do double writes' workaround + * we have to lock out interrupts to be safe. As we don't care + * of the value read we use an atomic rmw access to avoid costly + * cli/sti. Otherwise we use an even cheaper single atomic write + * to the APIC. + */ + unsigned int cfg; + + /* + * Wait for idle. + */ + __xapic_wait_icr_idle(); + + /* + * No need to touch the target chip field + */ + cfg = __prepare_ICR(shortcut, vector, dest); + + /* + * Send the IPI. The write to APIC_ICR fires this off. + */ + native_apic_mem_write(APIC_ICR, cfg); +} + +/* + * This is used to send an IPI with no shorthand notation (the destination is + * specified in bits 56 to 63 of the ICR). + */ +void __default_send_IPI_dest_field(unsigned int mask, int vector, unsigned int dest) +{ + unsigned long cfg; + + /* + * Wait for idle. + */ + if (unlikely(vector == NMI_VECTOR)) + safe_apic_wait_icr_idle(); + else + __xapic_wait_icr_idle(); + + /* + * prepare target chip field + */ + cfg = __prepare_ICR2(mask); + native_apic_mem_write(APIC_ICR2, cfg); + + /* + * program the ICR + */ + cfg = __prepare_ICR(0, vector, dest); + + /* + * Send the IPI. The write to APIC_ICR fires this off. + */ + native_apic_mem_write(APIC_ICR, cfg); +} + +void default_send_IPI_single_phys(int cpu, int vector) +{ + unsigned long flags; + + local_irq_save(flags); + __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, cpu), + vector, APIC_DEST_PHYSICAL); + local_irq_restore(flags); +} + +void default_send_IPI_mask_sequence_phys(const struct cpumask *mask, int vector) +{ + unsigned long query_cpu; + unsigned long flags; + + /* + * Hack. The clustered APIC addressing mode doesn't allow us to send + * to an arbitrary mask, so I do a unicast to each CPU instead. + * - mbligh + */ + local_irq_save(flags); + for_each_cpu(query_cpu, mask) { + __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, + query_cpu), vector, APIC_DEST_PHYSICAL); + } + local_irq_restore(flags); +} + +void default_send_IPI_mask_allbutself_phys(const struct cpumask *mask, + int vector) +{ + unsigned int this_cpu = smp_processor_id(); + unsigned int query_cpu; + unsigned long flags; + + /* See Hack comment above */ + + local_irq_save(flags); + for_each_cpu(query_cpu, mask) { + if (query_cpu == this_cpu) + continue; + __default_send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, + query_cpu), vector, APIC_DEST_PHYSICAL); + } + local_irq_restore(flags); +} + +/* + * Helper function for APICs which insist on cpumasks + */ +void default_send_IPI_single(int cpu, int vector) +{ + apic->send_IPI_mask(cpumask_of(cpu), vector); +} + +#ifdef CONFIG_X86_32 + +void default_send_IPI_mask_sequence_logical(const struct cpumask *mask, + int vector) +{ + unsigned long flags; + unsigned int query_cpu; + + /* + * Hack. The clustered APIC addressing mode doesn't allow us to send + * to an arbitrary mask, so I do a unicasts to each CPU instead. This + * should be modified to do 1 message per cluster ID - mbligh + */ + + local_irq_save(flags); + for_each_cpu(query_cpu, mask) + __default_send_IPI_dest_field( + early_per_cpu(x86_cpu_to_logical_apicid, query_cpu), + vector, apic->dest_logical); + local_irq_restore(flags); +} + +void default_send_IPI_mask_allbutself_logical(const struct cpumask *mask, + int vector) +{ + unsigned long flags; + unsigned int query_cpu; + unsigned int this_cpu = smp_processor_id(); + + /* See Hack comment above */ + + local_irq_save(flags); + for_each_cpu(query_cpu, mask) { + if (query_cpu == this_cpu) + continue; + __default_send_IPI_dest_field( + early_per_cpu(x86_cpu_to_logical_apicid, query_cpu), + vector, apic->dest_logical); + } + local_irq_restore(flags); +} + +/* + * This is only used on smaller machines. + */ +void default_send_IPI_mask_logical(const struct cpumask *cpumask, int vector) +{ + unsigned long mask = cpumask_bits(cpumask)[0]; + unsigned long flags; + + if (!mask) + return; + + local_irq_save(flags); + WARN_ON(mask & ~cpumask_bits(cpu_online_mask)[0]); + __default_send_IPI_dest_field(mask, vector, apic->dest_logical); + local_irq_restore(flags); +} + +void default_send_IPI_allbutself(int vector) +{ + /* + * if there are no other CPUs in the system then we get an APIC send + * error if we try to broadcast, thus avoid sending IPIs in this case. + */ + if (!(num_online_cpus() > 1)) + return; + + __default_local_send_IPI_allbutself(vector); +} + +void default_send_IPI_all(int vector) +{ + __default_local_send_IPI_all(vector); +} + +void default_send_IPI_self(int vector) +{ + __default_send_IPI_shortcut(APIC_DEST_SELF, vector, apic->dest_logical); +} + +/* must come after the send_IPI functions above for inlining */ +static int convert_apicid_to_cpu(int apic_id) +{ + int i; + + for_each_possible_cpu(i) { + if (per_cpu(x86_cpu_to_apicid, i) == apic_id) + return i; + } + return -1; +} + +int safe_smp_processor_id(void) +{ + int apicid, cpuid; + + if (!boot_cpu_has(X86_FEATURE_APIC)) + return 0; + + apicid = hard_smp_processor_id(); + if (apicid == BAD_APICID) + return 0; + + cpuid = convert_apicid_to_cpu(apicid); + + return cpuid >= 0 ? cpuid : 0; +} +#endif |