diff options
Diffstat (limited to 'arch/x86/kernel/apic/vector.c')
| -rw-r--r-- | arch/x86/kernel/apic/vector.c | 1394 |
1 files changed, 1394 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c new file mode 100644 index 000000000..319448d87 --- /dev/null +++ b/arch/x86/kernel/apic/vector.c @@ -0,0 +1,1394 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Local APIC related interfaces to support IOAPIC, MSI, etc. + * + * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo + * Moved from arch/x86/kernel/apic/io_apic.c. + * Jiang Liu <jiang.liu@linux.intel.com> + * Enable support of hierarchical irqdomains + */ +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/seq_file.h> +#include <linux/init.h> +#include <linux/compiler.h> +#include <linux/slab.h> +#include <asm/irqdomain.h> +#include <asm/hw_irq.h> +#include <asm/traps.h> +#include <asm/apic.h> +#include <asm/i8259.h> +#include <asm/desc.h> +#include <asm/irq_remapping.h> + +#include <asm/trace/irq_vectors.h> + +struct apic_chip_data { + struct irq_cfg hw_irq_cfg; + unsigned int vector; + unsigned int prev_vector; + unsigned int cpu; + unsigned int prev_cpu; + unsigned int irq; + struct hlist_node clist; + unsigned int move_in_progress : 1, + is_managed : 1, + can_reserve : 1, + has_reserved : 1; +}; + +struct irq_domain *x86_vector_domain; +EXPORT_SYMBOL_GPL(x86_vector_domain); +static DEFINE_RAW_SPINLOCK(vector_lock); +static cpumask_var_t vector_searchmask; +static struct irq_chip lapic_controller; +static struct irq_matrix *vector_matrix; +#ifdef CONFIG_SMP + +static void vector_cleanup_callback(struct timer_list *tmr); + +struct vector_cleanup { + struct hlist_head head; + struct timer_list timer; +}; + +static DEFINE_PER_CPU(struct vector_cleanup, vector_cleanup) = { + .head = HLIST_HEAD_INIT, + .timer = __TIMER_INITIALIZER(vector_cleanup_callback, TIMER_PINNED), +}; +#endif + +void lock_vector_lock(void) +{ + /* Used to the online set of cpus does not change + * during assign_irq_vector. + */ + raw_spin_lock(&vector_lock); +} + +void unlock_vector_lock(void) +{ + raw_spin_unlock(&vector_lock); +} + +void init_irq_alloc_info(struct irq_alloc_info *info, + const struct cpumask *mask) +{ + memset(info, 0, sizeof(*info)); + info->mask = mask; +} + +void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src) +{ + if (src) + *dst = *src; + else + memset(dst, 0, sizeof(*dst)); +} + +static struct apic_chip_data *apic_chip_data(struct irq_data *irqd) +{ + if (!irqd) + return NULL; + + while (irqd->parent_data) + irqd = irqd->parent_data; + + return irqd->chip_data; +} + +struct irq_cfg *irqd_cfg(struct irq_data *irqd) +{ + struct apic_chip_data *apicd = apic_chip_data(irqd); + + return apicd ? &apicd->hw_irq_cfg : NULL; +} +EXPORT_SYMBOL_GPL(irqd_cfg); + +struct irq_cfg *irq_cfg(unsigned int irq) +{ + return irqd_cfg(irq_get_irq_data(irq)); +} + +static struct apic_chip_data *alloc_apic_chip_data(int node) +{ + struct apic_chip_data *apicd; + + apicd = kzalloc_node(sizeof(*apicd), GFP_KERNEL, node); + if (apicd) + INIT_HLIST_NODE(&apicd->clist); + return apicd; +} + +static void free_apic_chip_data(struct apic_chip_data *apicd) +{ + kfree(apicd); +} + +static void apic_update_irq_cfg(struct irq_data *irqd, unsigned int vector, + unsigned int cpu) +{ + struct apic_chip_data *apicd = apic_chip_data(irqd); + + lockdep_assert_held(&vector_lock); + + apicd->hw_irq_cfg.vector = vector; + apicd->hw_irq_cfg.dest_apicid = apic->calc_dest_apicid(cpu); + irq_data_update_effective_affinity(irqd, cpumask_of(cpu)); + trace_vector_config(irqd->irq, vector, cpu, + apicd->hw_irq_cfg.dest_apicid); +} + +static void apic_update_vector(struct irq_data *irqd, unsigned int newvec, + unsigned int newcpu) +{ + struct apic_chip_data *apicd = apic_chip_data(irqd); + struct irq_desc *desc = irq_data_to_desc(irqd); + bool managed = irqd_affinity_is_managed(irqd); + + lockdep_assert_held(&vector_lock); + + trace_vector_update(irqd->irq, newvec, newcpu, apicd->vector, + apicd->cpu); + + /* + * If there is no vector associated or if the associated vector is + * the shutdown vector, which is associated to make PCI/MSI + * shutdown mode work, then there is nothing to release. Clear out + * prev_vector for this and the offlined target case. + */ + apicd->prev_vector = 0; + if (!apicd->vector || apicd->vector == MANAGED_IRQ_SHUTDOWN_VECTOR) + goto setnew; + /* + * If the target CPU of the previous vector is online, then mark + * the vector as move in progress and store it for cleanup when the + * first interrupt on the new vector arrives. If the target CPU is + * offline then the regular release mechanism via the cleanup + * vector is not possible and the vector can be immediately freed + * in the underlying matrix allocator. + */ + if (cpu_online(apicd->cpu)) { + apicd->move_in_progress = true; + apicd->prev_vector = apicd->vector; + apicd->prev_cpu = apicd->cpu; + WARN_ON_ONCE(apicd->cpu == newcpu); + } else { + irq_matrix_free(vector_matrix, apicd->cpu, apicd->vector, + managed); + } + +setnew: + apicd->vector = newvec; + apicd->cpu = newcpu; + BUG_ON(!IS_ERR_OR_NULL(per_cpu(vector_irq, newcpu)[newvec])); + per_cpu(vector_irq, newcpu)[newvec] = desc; +} + +static void vector_assign_managed_shutdown(struct irq_data *irqd) +{ + unsigned int cpu = cpumask_first(cpu_online_mask); + + apic_update_irq_cfg(irqd, MANAGED_IRQ_SHUTDOWN_VECTOR, cpu); +} + +static int reserve_managed_vector(struct irq_data *irqd) +{ + const struct cpumask *affmsk = irq_data_get_affinity_mask(irqd); + struct apic_chip_data *apicd = apic_chip_data(irqd); + unsigned long flags; + int ret; + + raw_spin_lock_irqsave(&vector_lock, flags); + apicd->is_managed = true; + ret = irq_matrix_reserve_managed(vector_matrix, affmsk); + raw_spin_unlock_irqrestore(&vector_lock, flags); + trace_vector_reserve_managed(irqd->irq, ret); + return ret; +} + +static void reserve_irq_vector_locked(struct irq_data *irqd) +{ + struct apic_chip_data *apicd = apic_chip_data(irqd); + + irq_matrix_reserve(vector_matrix); + apicd->can_reserve = true; + apicd->has_reserved = true; + irqd_set_can_reserve(irqd); + trace_vector_reserve(irqd->irq, 0); + vector_assign_managed_shutdown(irqd); +} + +static int reserve_irq_vector(struct irq_data *irqd) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&vector_lock, flags); + reserve_irq_vector_locked(irqd); + raw_spin_unlock_irqrestore(&vector_lock, flags); + return 0; +} + +static int +assign_vector_locked(struct irq_data *irqd, const struct cpumask *dest) +{ + struct apic_chip_data *apicd = apic_chip_data(irqd); + bool resvd = apicd->has_reserved; + unsigned int cpu = apicd->cpu; + int vector = apicd->vector; + + lockdep_assert_held(&vector_lock); + + /* + * If the current target CPU is online and in the new requested + * affinity mask, there is no point in moving the interrupt from + * one CPU to another. + */ + if (vector && cpu_online(cpu) && cpumask_test_cpu(cpu, dest)) + return 0; + + /* + * Careful here. @apicd might either have move_in_progress set or + * be enqueued for cleanup. Assigning a new vector would either + * leave a stale vector on some CPU around or in case of a pending + * cleanup corrupt the hlist. + */ + if (apicd->move_in_progress || !hlist_unhashed(&apicd->clist)) + return -EBUSY; + + vector = irq_matrix_alloc(vector_matrix, dest, resvd, &cpu); + trace_vector_alloc(irqd->irq, vector, resvd, vector); + if (vector < 0) + return vector; + apic_update_vector(irqd, vector, cpu); + apic_update_irq_cfg(irqd, vector, cpu); + + return 0; +} + +static int assign_irq_vector(struct irq_data *irqd, const struct cpumask *dest) +{ + unsigned long flags; + int ret; + + raw_spin_lock_irqsave(&vector_lock, flags); + cpumask_and(vector_searchmask, dest, cpu_online_mask); + ret = assign_vector_locked(irqd, vector_searchmask); + raw_spin_unlock_irqrestore(&vector_lock, flags); + return ret; +} + +static int assign_irq_vector_any_locked(struct irq_data *irqd) +{ + /* Get the affinity mask - either irq_default_affinity or (user) set */ + const struct cpumask *affmsk = irq_data_get_affinity_mask(irqd); + int node = irq_data_get_node(irqd); + + if (node != NUMA_NO_NODE) { + /* Try the intersection of @affmsk and node mask */ + cpumask_and(vector_searchmask, cpumask_of_node(node), affmsk); + if (!assign_vector_locked(irqd, vector_searchmask)) + return 0; + } + + /* Try the full affinity mask */ + cpumask_and(vector_searchmask, affmsk, cpu_online_mask); + if (!assign_vector_locked(irqd, vector_searchmask)) + return 0; + + if (node != NUMA_NO_NODE) { + /* Try the node mask */ + if (!assign_vector_locked(irqd, cpumask_of_node(node))) + return 0; + } + + /* Try the full online mask */ + return assign_vector_locked(irqd, cpu_online_mask); +} + +static int +assign_irq_vector_policy(struct irq_data *irqd, struct irq_alloc_info *info) +{ + if (irqd_affinity_is_managed(irqd)) + return reserve_managed_vector(irqd); + if (info->mask) + return assign_irq_vector(irqd, info->mask); + /* + * Make only a global reservation with no guarantee. A real vector + * is associated at activation time. + */ + return reserve_irq_vector(irqd); +} + +static int +assign_managed_vector(struct irq_data *irqd, const struct cpumask *dest) +{ + const struct cpumask *affmsk = irq_data_get_affinity_mask(irqd); + struct apic_chip_data *apicd = apic_chip_data(irqd); + int vector, cpu; + + cpumask_and(vector_searchmask, dest, affmsk); + + /* set_affinity might call here for nothing */ + if (apicd->vector && cpumask_test_cpu(apicd->cpu, vector_searchmask)) + return 0; + vector = irq_matrix_alloc_managed(vector_matrix, vector_searchmask, + &cpu); + trace_vector_alloc_managed(irqd->irq, vector, vector); + if (vector < 0) + return vector; + apic_update_vector(irqd, vector, cpu); + apic_update_irq_cfg(irqd, vector, cpu); + return 0; +} + +static void clear_irq_vector(struct irq_data *irqd) +{ + struct apic_chip_data *apicd = apic_chip_data(irqd); + bool managed = irqd_affinity_is_managed(irqd); + unsigned int vector = apicd->vector; + + lockdep_assert_held(&vector_lock); + + if (!vector) + return; + + trace_vector_clear(irqd->irq, vector, apicd->cpu, apicd->prev_vector, + apicd->prev_cpu); + + per_cpu(vector_irq, apicd->cpu)[vector] = VECTOR_SHUTDOWN; + irq_matrix_free(vector_matrix, apicd->cpu, vector, managed); + apicd->vector = 0; + + /* Clean up move in progress */ + vector = apicd->prev_vector; + if (!vector) + return; + + per_cpu(vector_irq, apicd->prev_cpu)[vector] = VECTOR_SHUTDOWN; + irq_matrix_free(vector_matrix, apicd->prev_cpu, vector, managed); + apicd->prev_vector = 0; + apicd->move_in_progress = 0; + hlist_del_init(&apicd->clist); +} + +static void x86_vector_deactivate(struct irq_domain *dom, struct irq_data *irqd) +{ + struct apic_chip_data *apicd = apic_chip_data(irqd); + unsigned long flags; + + trace_vector_deactivate(irqd->irq, apicd->is_managed, + apicd->can_reserve, false); + + /* Regular fixed assigned interrupt */ + if (!apicd->is_managed && !apicd->can_reserve) + return; + /* If the interrupt has a global reservation, nothing to do */ + if (apicd->has_reserved) + return; + + raw_spin_lock_irqsave(&vector_lock, flags); + clear_irq_vector(irqd); + if (apicd->can_reserve) + reserve_irq_vector_locked(irqd); + else + vector_assign_managed_shutdown(irqd); + raw_spin_unlock_irqrestore(&vector_lock, flags); +} + +static int activate_reserved(struct irq_data *irqd) +{ + struct apic_chip_data *apicd = apic_chip_data(irqd); + int ret; + + ret = assign_irq_vector_any_locked(irqd); + if (!ret) { + apicd->has_reserved = false; + /* + * Core might have disabled reservation mode after + * allocating the irq descriptor. Ideally this should + * happen before allocation time, but that would require + * completely convoluted ways of transporting that + * information. + */ + if (!irqd_can_reserve(irqd)) + apicd->can_reserve = false; + } + + /* + * Check to ensure that the effective affinity mask is a subset + * the user supplied affinity mask, and warn the user if it is not + */ + if (!cpumask_subset(irq_data_get_effective_affinity_mask(irqd), + irq_data_get_affinity_mask(irqd))) { + pr_warn("irq %u: Affinity broken due to vector space exhaustion.\n", + irqd->irq); + } + + return ret; +} + +static int activate_managed(struct irq_data *irqd) +{ + const struct cpumask *dest = irq_data_get_affinity_mask(irqd); + int ret; + + cpumask_and(vector_searchmask, dest, cpu_online_mask); + if (WARN_ON_ONCE(cpumask_empty(vector_searchmask))) { + /* Something in the core code broke! Survive gracefully */ + pr_err("Managed startup for irq %u, but no CPU\n", irqd->irq); + return -EINVAL; + } + + ret = assign_managed_vector(irqd, vector_searchmask); + /* + * This should not happen. The vector reservation got buggered. Handle + * it gracefully. + */ + if (WARN_ON_ONCE(ret < 0)) { + pr_err("Managed startup irq %u, no vector available\n", + irqd->irq); + } + return ret; +} + +static int x86_vector_activate(struct irq_domain *dom, struct irq_data *irqd, + bool reserve) +{ + struct apic_chip_data *apicd = apic_chip_data(irqd); + unsigned long flags; + int ret = 0; + + trace_vector_activate(irqd->irq, apicd->is_managed, + apicd->can_reserve, reserve); + + raw_spin_lock_irqsave(&vector_lock, flags); + if (!apicd->can_reserve && !apicd->is_managed) + assign_irq_vector_any_locked(irqd); + else if (reserve || irqd_is_managed_and_shutdown(irqd)) + vector_assign_managed_shutdown(irqd); + else if (apicd->is_managed) + ret = activate_managed(irqd); + else if (apicd->has_reserved) + ret = activate_reserved(irqd); + raw_spin_unlock_irqrestore(&vector_lock, flags); + return ret; +} + +static void vector_free_reserved_and_managed(struct irq_data *irqd) +{ + const struct cpumask *dest = irq_data_get_affinity_mask(irqd); + struct apic_chip_data *apicd = apic_chip_data(irqd); + + trace_vector_teardown(irqd->irq, apicd->is_managed, + apicd->has_reserved); + + if (apicd->has_reserved) + irq_matrix_remove_reserved(vector_matrix); + if (apicd->is_managed) + irq_matrix_remove_managed(vector_matrix, dest); +} + +static void x86_vector_free_irqs(struct irq_domain *domain, + unsigned int virq, unsigned int nr_irqs) +{ + struct apic_chip_data *apicd; + struct irq_data *irqd; + unsigned long flags; + int i; + + for (i = 0; i < nr_irqs; i++) { + irqd = irq_domain_get_irq_data(x86_vector_domain, virq + i); + if (irqd && irqd->chip_data) { + raw_spin_lock_irqsave(&vector_lock, flags); + clear_irq_vector(irqd); + vector_free_reserved_and_managed(irqd); + apicd = irqd->chip_data; + irq_domain_reset_irq_data(irqd); + raw_spin_unlock_irqrestore(&vector_lock, flags); + free_apic_chip_data(apicd); + } + } +} + +static bool vector_configure_legacy(unsigned int virq, struct irq_data *irqd, + struct apic_chip_data *apicd) +{ + unsigned long flags; + bool realloc = false; + + apicd->vector = ISA_IRQ_VECTOR(virq); + apicd->cpu = 0; + + raw_spin_lock_irqsave(&vector_lock, flags); + /* + * If the interrupt is activated, then it must stay at this vector + * position. That's usually the timer interrupt (0). + */ + if (irqd_is_activated(irqd)) { + trace_vector_setup(virq, true, 0); + apic_update_irq_cfg(irqd, apicd->vector, apicd->cpu); + } else { + /* Release the vector */ + apicd->can_reserve = true; + irqd_set_can_reserve(irqd); + clear_irq_vector(irqd); + realloc = true; + } + raw_spin_unlock_irqrestore(&vector_lock, flags); + return realloc; +} + +static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *arg) +{ + struct irq_alloc_info *info = arg; + struct apic_chip_data *apicd; + struct irq_data *irqd; + int i, err, node; + + if (apic_is_disabled) + return -ENXIO; + + /* + * Catch any attempt to touch the cascade interrupt on a PIC + * equipped system. + */ + if (WARN_ON_ONCE(info->flags & X86_IRQ_ALLOC_LEGACY && + virq == PIC_CASCADE_IR)) + return -EINVAL; + + for (i = 0; i < nr_irqs; i++) { + irqd = irq_domain_get_irq_data(domain, virq + i); + BUG_ON(!irqd); + node = irq_data_get_node(irqd); + WARN_ON_ONCE(irqd->chip_data); + apicd = alloc_apic_chip_data(node); + if (!apicd) { + err = -ENOMEM; + goto error; + } + + apicd->irq = virq + i; + irqd->chip = &lapic_controller; + irqd->chip_data = apicd; + irqd->hwirq = virq + i; + irqd_set_single_target(irqd); + /* + * Prevent that any of these interrupts is invoked in + * non interrupt context via e.g. generic_handle_irq() + * as that can corrupt the affinity move state. + */ + irqd_set_handle_enforce_irqctx(irqd); + + /* Don't invoke affinity setter on deactivated interrupts */ + irqd_set_affinity_on_activate(irqd); + + /* + * Legacy vectors are already assigned when the IOAPIC + * takes them over. They stay on the same vector. This is + * required for check_timer() to work correctly as it might + * switch back to legacy mode. Only update the hardware + * config. + */ + if (info->flags & X86_IRQ_ALLOC_LEGACY) { + if (!vector_configure_legacy(virq + i, irqd, apicd)) + continue; + } + + err = assign_irq_vector_policy(irqd, info); + trace_vector_setup(virq + i, false, err); + if (err) { + irqd->chip_data = NULL; + free_apic_chip_data(apicd); + goto error; + } + } + + return 0; + +error: + x86_vector_free_irqs(domain, virq, i); + return err; +} + +#ifdef CONFIG_GENERIC_IRQ_DEBUGFS +static void x86_vector_debug_show(struct seq_file *m, struct irq_domain *d, + struct irq_data *irqd, int ind) +{ + struct apic_chip_data apicd; + unsigned long flags; + int irq; + + if (!irqd) { + irq_matrix_debug_show(m, vector_matrix, ind); + return; + } + + irq = irqd->irq; + if (irq < nr_legacy_irqs() && !test_bit(irq, &io_apic_irqs)) { + seq_printf(m, "%*sVector: %5d\n", ind, "", ISA_IRQ_VECTOR(irq)); + seq_printf(m, "%*sTarget: Legacy PIC all CPUs\n", ind, ""); + return; + } + + if (!irqd->chip_data) { + seq_printf(m, "%*sVector: Not assigned\n", ind, ""); + return; + } + + raw_spin_lock_irqsave(&vector_lock, flags); + memcpy(&apicd, irqd->chip_data, sizeof(apicd)); + raw_spin_unlock_irqrestore(&vector_lock, flags); + + seq_printf(m, "%*sVector: %5u\n", ind, "", apicd.vector); + seq_printf(m, "%*sTarget: %5u\n", ind, "", apicd.cpu); + if (apicd.prev_vector) { + seq_printf(m, "%*sPrevious vector: %5u\n", ind, "", apicd.prev_vector); + seq_printf(m, "%*sPrevious target: %5u\n", ind, "", apicd.prev_cpu); + } + seq_printf(m, "%*smove_in_progress: %u\n", ind, "", apicd.move_in_progress ? 1 : 0); + seq_printf(m, "%*sis_managed: %u\n", ind, "", apicd.is_managed ? 1 : 0); + seq_printf(m, "%*scan_reserve: %u\n", ind, "", apicd.can_reserve ? 1 : 0); + seq_printf(m, "%*shas_reserved: %u\n", ind, "", apicd.has_reserved ? 1 : 0); + seq_printf(m, "%*scleanup_pending: %u\n", ind, "", !hlist_unhashed(&apicd.clist)); +} +#endif + +int x86_fwspec_is_ioapic(struct irq_fwspec *fwspec) +{ + if (fwspec->param_count != 1) + return 0; + + if (is_fwnode_irqchip(fwspec->fwnode)) { + const char *fwname = fwnode_get_name(fwspec->fwnode); + return fwname && !strncmp(fwname, "IO-APIC-", 8) && + simple_strtol(fwname+8, NULL, 10) == fwspec->param[0]; + } + return to_of_node(fwspec->fwnode) && + of_device_is_compatible(to_of_node(fwspec->fwnode), + "intel,ce4100-ioapic"); +} + +int x86_fwspec_is_hpet(struct irq_fwspec *fwspec) +{ + if (fwspec->param_count != 1) + return 0; + + if (is_fwnode_irqchip(fwspec->fwnode)) { + const char *fwname = fwnode_get_name(fwspec->fwnode); + return fwname && !strncmp(fwname, "HPET-MSI-", 9) && + simple_strtol(fwname+9, NULL, 10) == fwspec->param[0]; + } + return 0; +} + +static int x86_vector_select(struct irq_domain *d, struct irq_fwspec *fwspec, + enum irq_domain_bus_token bus_token) +{ + /* + * HPET and I/OAPIC cannot be parented in the vector domain + * if IRQ remapping is enabled. APIC IDs above 15 bits are + * only permitted if IRQ remapping is enabled, so check that. + */ + if (apic_id_valid(32768)) + return 0; + + return x86_fwspec_is_ioapic(fwspec) || x86_fwspec_is_hpet(fwspec); +} + +static const struct irq_domain_ops x86_vector_domain_ops = { + .select = x86_vector_select, + .alloc = x86_vector_alloc_irqs, + .free = x86_vector_free_irqs, + .activate = x86_vector_activate, + .deactivate = x86_vector_deactivate, +#ifdef CONFIG_GENERIC_IRQ_DEBUGFS + .debug_show = x86_vector_debug_show, +#endif +}; + +int __init arch_probe_nr_irqs(void) +{ + int nr; + + if (nr_irqs > (NR_VECTORS * nr_cpu_ids)) + nr_irqs = NR_VECTORS * nr_cpu_ids; + + nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids; +#if defined(CONFIG_PCI_MSI) + /* + * for MSI and HT dyn irq + */ + if (gsi_top <= NR_IRQS_LEGACY) + nr += 8 * nr_cpu_ids; + else + nr += gsi_top * 16; +#endif + if (nr < nr_irqs) + nr_irqs = nr; + + /* + * We don't know if PIC is present at this point so we need to do + * probe() to get the right number of legacy IRQs. + */ + return legacy_pic->probe(); +} + +void lapic_assign_legacy_vector(unsigned int irq, bool replace) +{ + /* + * Use assign system here so it wont get accounted as allocated + * and moveable in the cpu hotplug check and it prevents managed + * irq reservation from touching it. + */ + irq_matrix_assign_system(vector_matrix, ISA_IRQ_VECTOR(irq), replace); +} + +void __init lapic_update_legacy_vectors(void) +{ + unsigned int i; + + if (IS_ENABLED(CONFIG_X86_IO_APIC) && nr_ioapics > 0) + return; + + /* + * If the IO/APIC is disabled via config, kernel command line or + * lack of enumeration then all legacy interrupts are routed + * through the PIC. Make sure that they are marked as legacy + * vectors. PIC_CASCADE_IRQ has already been marked in + * lapic_assign_system_vectors(). + */ + for (i = 0; i < nr_legacy_irqs(); i++) { + if (i != PIC_CASCADE_IR) + lapic_assign_legacy_vector(i, true); + } +} + +void __init lapic_assign_system_vectors(void) +{ + unsigned int i, vector; + + for_each_set_bit(vector, system_vectors, NR_VECTORS) + irq_matrix_assign_system(vector_matrix, vector, false); + + if (nr_legacy_irqs() > 1) + lapic_assign_legacy_vector(PIC_CASCADE_IR, false); + + /* System vectors are reserved, online it */ + irq_matrix_online(vector_matrix); + + /* Mark the preallocated legacy interrupts */ + for (i = 0; i < nr_legacy_irqs(); i++) { + /* + * Don't touch the cascade interrupt. It's unusable + * on PIC equipped machines. See the large comment + * in the IO/APIC code. + */ + if (i != PIC_CASCADE_IR) + irq_matrix_assign(vector_matrix, ISA_IRQ_VECTOR(i)); + } +} + +int __init arch_early_irq_init(void) +{ + struct fwnode_handle *fn; + + fn = irq_domain_alloc_named_fwnode("VECTOR"); + BUG_ON(!fn); + x86_vector_domain = irq_domain_create_tree(fn, &x86_vector_domain_ops, + NULL); + BUG_ON(x86_vector_domain == NULL); + irq_set_default_host(x86_vector_domain); + + BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL)); + + /* + * Allocate the vector matrix allocator data structure and limit the + * search area. + */ + vector_matrix = irq_alloc_matrix(NR_VECTORS, FIRST_EXTERNAL_VECTOR, + FIRST_SYSTEM_VECTOR); + BUG_ON(!vector_matrix); + + return arch_early_ioapic_init(); +} + +#ifdef CONFIG_SMP + +static struct irq_desc *__setup_vector_irq(int vector) +{ + int isairq = vector - ISA_IRQ_VECTOR(0); + + /* Check whether the irq is in the legacy space */ + if (isairq < 0 || isairq >= nr_legacy_irqs()) + return VECTOR_UNUSED; + /* Check whether the irq is handled by the IOAPIC */ + if (test_bit(isairq, &io_apic_irqs)) + return VECTOR_UNUSED; + return irq_to_desc(isairq); +} + +/* Online the local APIC infrastructure and initialize the vectors */ +void lapic_online(void) +{ + unsigned int vector; + + lockdep_assert_held(&vector_lock); + + /* Online the vector matrix array for this CPU */ + irq_matrix_online(vector_matrix); + + /* + * The interrupt affinity logic never targets interrupts to offline + * CPUs. The exception are the legacy PIC interrupts. In general + * they are only targeted to CPU0, but depending on the platform + * they can be distributed to any online CPU in hardware. The + * kernel has no influence on that. So all active legacy vectors + * must be installed on all CPUs. All non legacy interrupts can be + * cleared. + */ + for (vector = 0; vector < NR_VECTORS; vector++) + this_cpu_write(vector_irq[vector], __setup_vector_irq(vector)); +} + +static void __vector_cleanup(struct vector_cleanup *cl, bool check_irr); + +void lapic_offline(void) +{ + struct vector_cleanup *cl = this_cpu_ptr(&vector_cleanup); + + lock_vector_lock(); + + /* In case the vector cleanup timer has not expired */ + __vector_cleanup(cl, false); + + irq_matrix_offline(vector_matrix); + WARN_ON_ONCE(try_to_del_timer_sync(&cl->timer) < 0); + WARN_ON_ONCE(!hlist_empty(&cl->head)); + + unlock_vector_lock(); +} + +static int apic_set_affinity(struct irq_data *irqd, + const struct cpumask *dest, bool force) +{ + int err; + + if (WARN_ON_ONCE(!irqd_is_activated(irqd))) + return -EIO; + + raw_spin_lock(&vector_lock); + cpumask_and(vector_searchmask, dest, cpu_online_mask); + if (irqd_affinity_is_managed(irqd)) + err = assign_managed_vector(irqd, vector_searchmask); + else + err = assign_vector_locked(irqd, vector_searchmask); + raw_spin_unlock(&vector_lock); + return err ? err : IRQ_SET_MASK_OK; +} + +#else +# define apic_set_affinity NULL +#endif + +static int apic_retrigger_irq(struct irq_data *irqd) +{ + struct apic_chip_data *apicd = apic_chip_data(irqd); + unsigned long flags; + + raw_spin_lock_irqsave(&vector_lock, flags); + __apic_send_IPI(apicd->cpu, apicd->vector); + raw_spin_unlock_irqrestore(&vector_lock, flags); + + return 1; +} + +void apic_ack_irq(struct irq_data *irqd) +{ + irq_move_irq(irqd); + apic_eoi(); +} + +void apic_ack_edge(struct irq_data *irqd) +{ + irq_complete_move(irqd_cfg(irqd)); + apic_ack_irq(irqd); +} + +static void x86_vector_msi_compose_msg(struct irq_data *data, + struct msi_msg *msg) +{ + __irq_msi_compose_msg(irqd_cfg(data), msg, false); +} + +static struct irq_chip lapic_controller = { + .name = "APIC", + .irq_ack = apic_ack_edge, + .irq_set_affinity = apic_set_affinity, + .irq_compose_msi_msg = x86_vector_msi_compose_msg, + .irq_retrigger = apic_retrigger_irq, +}; + +#ifdef CONFIG_SMP + +static void free_moved_vector(struct apic_chip_data *apicd) +{ + unsigned int vector = apicd->prev_vector; + unsigned int cpu = apicd->prev_cpu; + bool managed = apicd->is_managed; + + /* + * Managed interrupts are usually not migrated away + * from an online CPU, but CPU isolation 'managed_irq' + * can make that happen. + * 1) Activation does not take the isolation into account + * to keep the code simple + * 2) Migration away from an isolated CPU can happen when + * a non-isolated CPU which is in the calculated + * affinity mask comes online. + */ + trace_vector_free_moved(apicd->irq, cpu, vector, managed); + irq_matrix_free(vector_matrix, cpu, vector, managed); + per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED; + hlist_del_init(&apicd->clist); + apicd->prev_vector = 0; + apicd->move_in_progress = 0; +} + +static void __vector_cleanup(struct vector_cleanup *cl, bool check_irr) +{ + struct apic_chip_data *apicd; + struct hlist_node *tmp; + bool rearm = false; + + lockdep_assert_held(&vector_lock); + + hlist_for_each_entry_safe(apicd, tmp, &cl->head, clist) { + unsigned int irr, vector = apicd->prev_vector; + + /* + * Paranoia: Check if the vector that needs to be cleaned + * up is registered at the APICs IRR. That's clearly a + * hardware issue if the vector arrived on the old target + * _after_ interrupts were disabled above. Keep @apicd + * on the list and schedule the timer again to give the CPU + * a chance to handle the pending interrupt. + * + * Do not check IRR when called from lapic_offline(), because + * fixup_irqs() was just called to scan IRR for set bits and + * forward them to new destination CPUs via IPIs. + */ + irr = check_irr ? apic_read(APIC_IRR + (vector / 32 * 0x10)) : 0; + if (irr & (1U << (vector % 32))) { + pr_warn_once("Moved interrupt pending in old target APIC %u\n", apicd->irq); + rearm = true; + continue; + } + free_moved_vector(apicd); + } + + /* + * Must happen under vector_lock to make the timer_pending() check + * in __vector_schedule_cleanup() race free against the rearm here. + */ + if (rearm) + mod_timer(&cl->timer, jiffies + 1); +} + +static void vector_cleanup_callback(struct timer_list *tmr) +{ + struct vector_cleanup *cl = container_of(tmr, typeof(*cl), timer); + + /* Prevent vectors vanishing under us */ + raw_spin_lock_irq(&vector_lock); + __vector_cleanup(cl, true); + raw_spin_unlock_irq(&vector_lock); +} + +static void __vector_schedule_cleanup(struct apic_chip_data *apicd) +{ + unsigned int cpu = apicd->prev_cpu; + + raw_spin_lock(&vector_lock); + apicd->move_in_progress = 0; + if (cpu_online(cpu)) { + struct vector_cleanup *cl = per_cpu_ptr(&vector_cleanup, cpu); + + hlist_add_head(&apicd->clist, &cl->head); + + /* + * The lockless timer_pending() check is safe here. If it + * returns true, then the callback will observe this new + * apic data in the hlist as everything is serialized by + * vector lock. + * + * If it returns false then the timer is either not armed + * or the other CPU executes the callback, which again + * would be blocked on vector lock. Rearming it in the + * latter case makes it fire for nothing. + * + * This is also safe against the callback rearming the timer + * because that's serialized via vector lock too. + */ + if (!timer_pending(&cl->timer)) { + cl->timer.expires = jiffies + 1; + add_timer_on(&cl->timer, cpu); + } + } else { + apicd->prev_vector = 0; + } + raw_spin_unlock(&vector_lock); +} + +void vector_schedule_cleanup(struct irq_cfg *cfg) +{ + struct apic_chip_data *apicd; + + apicd = container_of(cfg, struct apic_chip_data, hw_irq_cfg); + if (apicd->move_in_progress) + __vector_schedule_cleanup(apicd); +} + +void irq_complete_move(struct irq_cfg *cfg) +{ + struct apic_chip_data *apicd; + + apicd = container_of(cfg, struct apic_chip_data, hw_irq_cfg); + if (likely(!apicd->move_in_progress)) + return; + + /* + * If the interrupt arrived on the new target CPU, cleanup the + * vector on the old target CPU. A vector check is not required + * because an interrupt can never move from one vector to another + * on the same CPU. + */ + if (apicd->cpu == smp_processor_id()) + __vector_schedule_cleanup(apicd); +} + +/* + * Called from fixup_irqs() with @desc->lock held and interrupts disabled. + */ +void irq_force_complete_move(struct irq_desc *desc) +{ + struct apic_chip_data *apicd; + struct irq_data *irqd; + unsigned int vector; + + /* + * The function is called for all descriptors regardless of which + * irqdomain they belong to. For example if an IRQ is provided by + * an irq_chip as part of a GPIO driver, the chip data for that + * descriptor is specific to the irq_chip in question. + * + * Check first that the chip_data is what we expect + * (apic_chip_data) before touching it any further. + */ + irqd = irq_domain_get_irq_data(x86_vector_domain, + irq_desc_get_irq(desc)); + if (!irqd) + return; + + raw_spin_lock(&vector_lock); + apicd = apic_chip_data(irqd); + if (!apicd) + goto unlock; + + /* + * If prev_vector is empty, no action required. + */ + vector = apicd->prev_vector; + if (!vector) + goto unlock; + + /* + * This is tricky. If the cleanup of the old vector has not been + * done yet, then the following setaffinity call will fail with + * -EBUSY. This can leave the interrupt in a stale state. + * + * All CPUs are stuck in stop machine with interrupts disabled so + * calling __irq_complete_move() would be completely pointless. + * + * 1) The interrupt is in move_in_progress state. That means that we + * have not seen an interrupt since the io_apic was reprogrammed to + * the new vector. + * + * 2) The interrupt has fired on the new vector, but the cleanup IPIs + * have not been processed yet. + */ + if (apicd->move_in_progress) { + /* + * In theory there is a race: + * + * set_ioapic(new_vector) <-- Interrupt is raised before update + * is effective, i.e. it's raised on + * the old vector. + * + * So if the target cpu cannot handle that interrupt before + * the old vector is cleaned up, we get a spurious interrupt + * and in the worst case the ioapic irq line becomes stale. + * + * But in case of cpu hotplug this should be a non issue + * because if the affinity update happens right before all + * cpus rendezvous in stop machine, there is no way that the + * interrupt can be blocked on the target cpu because all cpus + * loops first with interrupts enabled in stop machine, so the + * old vector is not yet cleaned up when the interrupt fires. + * + * So the only way to run into this issue is if the delivery + * of the interrupt on the apic/system bus would be delayed + * beyond the point where the target cpu disables interrupts + * in stop machine. I doubt that it can happen, but at least + * there is a theoretical chance. Virtualization might be + * able to expose this, but AFAICT the IOAPIC emulation is not + * as stupid as the real hardware. + * + * Anyway, there is nothing we can do about that at this point + * w/o refactoring the whole fixup_irq() business completely. + * We print at least the irq number and the old vector number, + * so we have the necessary information when a problem in that + * area arises. + */ + pr_warn("IRQ fixup: irq %d move in progress, old vector %d\n", + irqd->irq, vector); + } + free_moved_vector(apicd); +unlock: + raw_spin_unlock(&vector_lock); +} + +#ifdef CONFIG_HOTPLUG_CPU +/* + * Note, this is not accurate accounting, but at least good enough to + * prevent that the actual interrupt move will run out of vectors. + */ +int lapic_can_unplug_cpu(void) +{ + unsigned int rsvd, avl, tomove, cpu = smp_processor_id(); + int ret = 0; + + raw_spin_lock(&vector_lock); + tomove = irq_matrix_allocated(vector_matrix); + avl = irq_matrix_available(vector_matrix, true); + if (avl < tomove) { + pr_warn("CPU %u has %u vectors, %u available. Cannot disable CPU\n", + cpu, tomove, avl); + ret = -ENOSPC; + goto out; + } + rsvd = irq_matrix_reserved(vector_matrix); + if (avl < rsvd) { + pr_warn("Reserved vectors %u > available %u. IRQ request may fail\n", + rsvd, avl); + } +out: + raw_spin_unlock(&vector_lock); + return ret; +} +#endif /* HOTPLUG_CPU */ +#endif /* SMP */ + +static void __init print_APIC_field(int base) +{ + int i; + + printk(KERN_DEBUG); + + for (i = 0; i < 8; i++) + pr_cont("%08x", apic_read(base + i*0x10)); + + pr_cont("\n"); +} + +static void __init print_local_APIC(void *dummy) +{ + unsigned int i, v, ver, maxlvt; + u64 icr; + + pr_debug("printing local APIC contents on CPU#%d/%d:\n", + smp_processor_id(), read_apic_id()); + v = apic_read(APIC_ID); + pr_info("... APIC ID: %08x (%01x)\n", v, read_apic_id()); + v = apic_read(APIC_LVR); + pr_info("... APIC VERSION: %08x\n", v); + ver = GET_APIC_VERSION(v); + maxlvt = lapic_get_maxlvt(); + + v = apic_read(APIC_TASKPRI); + pr_debug("... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK); + + /* !82489DX */ + if (APIC_INTEGRATED(ver)) { + if (!APIC_XAPIC(ver)) { + v = apic_read(APIC_ARBPRI); + pr_debug("... APIC ARBPRI: %08x (%02x)\n", + v, v & APIC_ARBPRI_MASK); + } + v = apic_read(APIC_PROCPRI); + pr_debug("... APIC PROCPRI: %08x\n", v); + } + + /* + * Remote read supported only in the 82489DX and local APIC for + * Pentium processors. + */ + if (!APIC_INTEGRATED(ver) || maxlvt == 3) { + v = apic_read(APIC_RRR); + pr_debug("... APIC RRR: %08x\n", v); + } + + v = apic_read(APIC_LDR); + pr_debug("... APIC LDR: %08x\n", v); + if (!x2apic_enabled()) { + v = apic_read(APIC_DFR); + pr_debug("... APIC DFR: %08x\n", v); + } + v = apic_read(APIC_SPIV); + pr_debug("... APIC SPIV: %08x\n", v); + + pr_debug("... APIC ISR field:\n"); + print_APIC_field(APIC_ISR); + pr_debug("... APIC TMR field:\n"); + print_APIC_field(APIC_TMR); + pr_debug("... APIC IRR field:\n"); + print_APIC_field(APIC_IRR); + + /* !82489DX */ + if (APIC_INTEGRATED(ver)) { + /* Due to the Pentium erratum 3AP. */ + if (maxlvt > 3) + apic_write(APIC_ESR, 0); + + v = apic_read(APIC_ESR); + pr_debug("... APIC ESR: %08x\n", v); + } + + icr = apic_icr_read(); + pr_debug("... APIC ICR: %08x\n", (u32)icr); + pr_debug("... APIC ICR2: %08x\n", (u32)(icr >> 32)); + + v = apic_read(APIC_LVTT); + pr_debug("... APIC LVTT: %08x\n", v); + + if (maxlvt > 3) { + /* PC is LVT#4. */ + v = apic_read(APIC_LVTPC); + pr_debug("... APIC LVTPC: %08x\n", v); + } + v = apic_read(APIC_LVT0); + pr_debug("... APIC LVT0: %08x\n", v); + v = apic_read(APIC_LVT1); + pr_debug("... APIC LVT1: %08x\n", v); + + if (maxlvt > 2) { + /* ERR is LVT#3. */ + v = apic_read(APIC_LVTERR); + pr_debug("... APIC LVTERR: %08x\n", v); + } + + v = apic_read(APIC_TMICT); + pr_debug("... APIC TMICT: %08x\n", v); + v = apic_read(APIC_TMCCT); + pr_debug("... APIC TMCCT: %08x\n", v); + v = apic_read(APIC_TDCR); + pr_debug("... APIC TDCR: %08x\n", v); + + if (boot_cpu_has(X86_FEATURE_EXTAPIC)) { + v = apic_read(APIC_EFEAT); + maxlvt = (v >> 16) & 0xff; + pr_debug("... APIC EFEAT: %08x\n", v); + v = apic_read(APIC_ECTRL); + pr_debug("... APIC ECTRL: %08x\n", v); + for (i = 0; i < maxlvt; i++) { + v = apic_read(APIC_EILVTn(i)); + pr_debug("... APIC EILVT%d: %08x\n", i, v); + } + } + pr_cont("\n"); +} + +static void __init print_local_APICs(int maxcpu) +{ + int cpu; + + if (!maxcpu) + return; + + preempt_disable(); + for_each_online_cpu(cpu) { + if (cpu >= maxcpu) + break; + smp_call_function_single(cpu, print_local_APIC, NULL, 1); + } + preempt_enable(); +} + +static void __init print_PIC(void) +{ + unsigned int v; + unsigned long flags; + + if (!nr_legacy_irqs()) + return; + + pr_debug("\nprinting PIC contents\n"); + + raw_spin_lock_irqsave(&i8259A_lock, flags); + + v = inb(0xa1) << 8 | inb(0x21); + pr_debug("... PIC IMR: %04x\n", v); + + v = inb(0xa0) << 8 | inb(0x20); + pr_debug("... PIC IRR: %04x\n", v); + + outb(0x0b, 0xa0); + outb(0x0b, 0x20); + v = inb(0xa0) << 8 | inb(0x20); + outb(0x0a, 0xa0); + outb(0x0a, 0x20); + + raw_spin_unlock_irqrestore(&i8259A_lock, flags); + + pr_debug("... PIC ISR: %04x\n", v); + + v = inb(PIC_ELCR2) << 8 | inb(PIC_ELCR1); + pr_debug("... PIC ELCR: %04x\n", v); +} + +static int show_lapic __initdata = 1; +static __init int setup_show_lapic(char *arg) +{ + int num = -1; + + if (strcmp(arg, "all") == 0) { + show_lapic = CONFIG_NR_CPUS; + } else { + get_option(&arg, &num); + if (num >= 0) + show_lapic = num; + } + + return 1; +} +__setup("show_lapic=", setup_show_lapic); + +static int __init print_ICs(void) +{ + if (apic_verbosity == APIC_QUIET) + return 0; + + print_PIC(); + + /* don't print out if apic is not there */ + if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config()) + return 0; + + print_local_APICs(show_lapic); + print_IO_APICs(); + + return 0; +} + +late_initcall(print_ICs); |