diff options
Diffstat (limited to 'arch/um/kernel/irq.c')
| -rw-r--r-- | arch/um/kernel/irq.c | 877 |
1 files changed, 503 insertions, 374 deletions
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c index 3577118bb4a5..f4b13f15a9c1 100644 --- a/arch/um/kernel/irq.c +++ b/arch/um/kernel/irq.c @@ -19,27 +19,51 @@ #include <kern_util.h> #include <os.h> #include <irq_user.h> +#include <irq_kern.h> +#include <linux/time-internal.h> +DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); -extern void free_irqs(void); +#define irq_stats(x) (&per_cpu(irq_stat, x)) /* When epoll triggers we do not know why it did so * we can also have different IRQs for read and write. - * This is why we keep a small irq_fd array for each fd - + * This is why we keep a small irq_reg array for each fd - * one entry per IRQ type */ +struct irq_reg { + void *id; + int irq; + /* it's cheaper to store this than to query it */ + int events; + bool active; + bool pending; + bool wakeup; +#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT + bool pending_event; + void (*timetravel_handler)(int, int, void *, + struct time_travel_event *); + struct time_travel_event event; +#endif +}; struct irq_entry { - struct irq_entry *next; + struct list_head list; int fd; - struct irq_fd *irq_array[MAX_IRQ_TYPE + 1]; + struct irq_reg reg[NUM_IRQ_TYPES]; + bool suspended; + bool sigio_workaround; }; -static struct irq_entry *active_fds; - -static DEFINE_SPINLOCK(irq_lock); +static DEFINE_RAW_SPINLOCK(irq_lock); +static LIST_HEAD(active_fds); +static DECLARE_BITMAP(irqs_allocated, UM_LAST_SIGNAL_IRQ); +static bool irqs_suspended; +#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT +static bool irqs_pending; +#endif -static void irq_io_loop(struct irq_fd *irq, struct uml_pt_regs *regs) +static void irq_io_loop(struct irq_reg *irq, struct uml_pt_regs *regs) { /* * irq->active guards against reentry @@ -49,23 +73,140 @@ static void irq_io_loop(struct irq_fd *irq, struct uml_pt_regs *regs) */ if (irq->active) { irq->active = false; + do { irq->pending = false; do_IRQ(irq->irq, regs); - } while (irq->pending && (!irq->purge)); - if (!irq->purge) - irq->active = true; + } while (irq->pending); + + irq->active = true; } else { irq->pending = true; } } -void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs) +#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT +static void irq_event_handler(struct time_travel_event *ev) +{ + struct irq_reg *reg = container_of(ev, struct irq_reg, event); + + /* do nothing if suspended; just cause a wakeup and mark as pending */ + if (irqs_suspended) { + irqs_pending = true; + reg->pending_event = true; + return; + } + + generic_handle_irq(reg->irq); +} + +static bool irq_do_timetravel_handler(struct irq_entry *entry, + enum um_irq_type t) +{ + struct irq_reg *reg = &entry->reg[t]; + + if (!reg->timetravel_handler) + return false; + + /* + * Handle all messages - we might get multiple even while + * interrupts are already suspended, due to suspend order + * etc. Note that time_travel_add_irq_event() will not add + * an event twice, if it's pending already "first wins". + */ + reg->timetravel_handler(reg->irq, entry->fd, reg->id, ®->event); + + if (!reg->event.pending) + return false; + + return true; +} + +static void irq_do_pending_events(bool timetravel_handlers_only) +{ + struct irq_entry *entry; + + if (!irqs_pending || timetravel_handlers_only) + return; + + irqs_pending = false; + + list_for_each_entry(entry, &active_fds, list) { + enum um_irq_type t; + + for (t = 0; t < NUM_IRQ_TYPES; t++) { + struct irq_reg *reg = &entry->reg[t]; + + /* + * Any timetravel_handler was invoked already, just + * directly run the IRQ. + */ + if (reg->pending_event) { + irq_enter(); + generic_handle_irq(reg->irq); + irq_exit(); + reg->pending_event = false; + } + } + } +} +#else +static bool irq_do_timetravel_handler(struct irq_entry *entry, + enum um_irq_type t) +{ + return false; +} + +static void irq_do_pending_events(bool timetravel_handlers_only) +{ +} +#endif + +static void sigio_reg_handler(int idx, struct irq_entry *entry, enum um_irq_type t, + struct uml_pt_regs *regs, + bool timetravel_handlers_only) +{ + struct irq_reg *reg = &entry->reg[t]; + + if (!reg->events) + return; + + if (os_epoll_triggered(idx, reg->events) <= 0) + return; + + if (irq_do_timetravel_handler(entry, t)) + return; + + /* + * If we're called to only run time-travel handlers then don't + * actually proceed but mark sigio as pending (if applicable). + * For suspend/resume, timetravel_handlers_only may be true + * despite time-travel not being configured and used. + */ + if (timetravel_handlers_only) { +#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT + reg->pending_event = true; + irqs_pending = true; + mark_sigio_pending(); +#endif + return; + } + + irq_io_loop(reg, regs); +} + +static void _sigio_handler(struct uml_pt_regs *regs, + bool timetravel_handlers_only) { struct irq_entry *irq_entry; - struct irq_fd *irq; + int n, i; + + if (timetravel_handlers_only && !um_irq_timetravel_handler_used()) + return; - int n, i, j; + /* Flush out pending events that were ignored due to time-travel. */ + if (!irqs_suspended) + irq_do_pending_events(timetravel_handlers_only); while (1) { /* This is now lockless - epoll keeps back-referencesto the irqs @@ -84,294 +225,218 @@ void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs) } for (i = 0; i < n ; i++) { - /* Epoll back reference is the entry with 3 irq_fd - * leaves - one for each irq type. - */ - irq_entry = (struct irq_entry *) - os_epoll_get_data_pointer(i); - for (j = 0; j < MAX_IRQ_TYPE ; j++) { - irq = irq_entry->irq_array[j]; - if (irq == NULL) - continue; - if (os_epoll_triggered(i, irq->events) > 0) - irq_io_loop(irq, regs); - if (irq->purge) { - irq_entry->irq_array[j] = NULL; - kfree(irq); - } - } + enum um_irq_type t; + + irq_entry = os_epoll_get_data_pointer(i); + + for (t = 0; t < NUM_IRQ_TYPES; t++) + sigio_reg_handler(i, irq_entry, t, regs, + timetravel_handlers_only); } } - free_irqs(); + if (!timetravel_handlers_only) + free_irqs(); } -static int assign_epoll_events_to_irq(struct irq_entry *irq_entry) +void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs, + void *mc) { - int i; - int events = 0; - struct irq_fd *irq; - - for (i = 0; i < MAX_IRQ_TYPE ; i++) { - irq = irq_entry->irq_array[i]; - if (irq != NULL) - events = irq->events | events; - } - if (events > 0) { - /* os_add_epoll will call os_mod_epoll if this already exists */ - return os_add_epoll_fd(events, irq_entry->fd, irq_entry); - } - /* No events - delete */ - return os_del_epoll_fd(irq_entry->fd); + preempt_disable(); + _sigio_handler(regs, irqs_suspended); + preempt_enable(); } - - -static int activate_fd(int irq, int fd, int type, void *dev_id) +static struct irq_entry *get_irq_entry_by_fd(int fd) { - struct irq_fd *new_fd; - struct irq_entry *irq_entry; - int i, err, events; - unsigned long flags; - - err = os_set_fd_async(fd); - if (err < 0) - goto out; - - spin_lock_irqsave(&irq_lock, flags); + struct irq_entry *walk; - /* Check if we have an entry for this fd */ + lockdep_assert_held(&irq_lock); - err = -EBUSY; - for (irq_entry = active_fds; - irq_entry != NULL; irq_entry = irq_entry->next) { - if (irq_entry->fd == fd) - break; + list_for_each_entry(walk, &active_fds, list) { + if (walk->fd == fd) + return walk; } - if (irq_entry == NULL) { - /* This needs to be atomic as it may be called from an - * IRQ context. - */ - irq_entry = kmalloc(sizeof(struct irq_entry), GFP_ATOMIC); - if (irq_entry == NULL) { - printk(KERN_ERR - "Failed to allocate new IRQ entry\n"); - goto out_unlock; - } - irq_entry->fd = fd; - for (i = 0; i < MAX_IRQ_TYPE; i++) - irq_entry->irq_array[i] = NULL; - irq_entry->next = active_fds; - active_fds = irq_entry; - } + return NULL; +} - /* Check if we are trying to re-register an interrupt for a - * particular fd - */ +static void remove_irq_entry(struct irq_entry *to_free, bool remove) +{ + if (!to_free) + return; - if (irq_entry->irq_array[type] != NULL) { - printk(KERN_ERR - "Trying to reregister IRQ %d FD %d TYPE %d ID %p\n", - irq, fd, type, dev_id - ); - goto out_unlock; - } else { - /* New entry for this fd */ + if (remove) + os_del_epoll_fd(to_free->fd); + list_del(&to_free->list); +} - err = -ENOMEM; - new_fd = kmalloc(sizeof(struct irq_fd), GFP_ATOMIC); - if (new_fd == NULL) - goto out_unlock; +static bool update_irq_entry(struct irq_entry *entry) +{ + enum um_irq_type i; + int events = 0; - events = os_event_mask(type); - - *new_fd = ((struct irq_fd) { - .id = dev_id, - .irq = irq, - .type = type, - .events = events, - .active = true, - .pending = false, - .purge = false - }); - /* Turn off any IO on this fd - allows us to - * avoid locking the IRQ loop - */ - os_del_epoll_fd(irq_entry->fd); - irq_entry->irq_array[type] = new_fd; - } + for (i = 0; i < NUM_IRQ_TYPES; i++) + events |= entry->reg[i].events; - /* Turn back IO on with the correct (new) IO event mask */ - assign_epoll_events_to_irq(irq_entry); - spin_unlock_irqrestore(&irq_lock, flags); - maybe_sigio_broken(fd, (type != IRQ_NONE)); + if (events) { + /* will modify (instead of add) if needed */ + os_add_epoll_fd(events, entry->fd, entry); + return true; + } - return 0; -out_unlock: - spin_unlock_irqrestore(&irq_lock, flags); -out: - return err; + os_del_epoll_fd(entry->fd); + return false; } -/* - * Walk the IRQ list and dispose of any unused entries. - * Should be done under irq_lock. - */ +static struct irq_entry *update_or_remove_irq_entry(struct irq_entry *entry) +{ + if (update_irq_entry(entry)) + return NULL; + remove_irq_entry(entry, false); + return entry; +} -static void garbage_collect_irq_entries(void) +static int activate_fd(int irq, int fd, enum um_irq_type type, void *dev_id, + void (*timetravel_handler)(int, int, void *, + struct time_travel_event *)) { - int i; - bool reap; - struct irq_entry *walk; - struct irq_entry *previous = NULL; - struct irq_entry *to_free; + struct irq_entry *irq_entry, *to_free = NULL; + int err, events = os_event_mask(type); + unsigned long flags; - if (active_fds == NULL) - return; - walk = active_fds; - while (walk != NULL) { - reap = true; - for (i = 0; i < MAX_IRQ_TYPE ; i++) { - if (walk->irq_array[i] != NULL) { - reap = false; - break; - } + err = os_set_fd_async(fd); + if (err < 0) + goto out; + + raw_spin_lock_irqsave(&irq_lock, flags); + irq_entry = get_irq_entry_by_fd(fd); + if (irq_entry) { +already: + /* cannot register the same FD twice with the same type */ + if (WARN_ON(irq_entry->reg[type].events)) { + err = -EALREADY; + goto out_unlock; } - if (reap) { - if (previous == NULL) - active_fds = walk->next; - else - previous->next = walk->next; - to_free = walk; - } else { - to_free = NULL; + + /* temporarily disable to avoid IRQ-side locking */ + os_del_epoll_fd(fd); + } else { + struct irq_entry *new; + + /* don't restore interrupts */ + raw_spin_unlock(&irq_lock); + new = kzalloc(sizeof(*irq_entry), GFP_ATOMIC); + if (!new) { + local_irq_restore(flags); + return -ENOMEM; + } + raw_spin_lock(&irq_lock); + irq_entry = get_irq_entry_by_fd(fd); + if (irq_entry) { + to_free = new; + goto already; } - walk = walk->next; - kfree(to_free); + irq_entry = new; + irq_entry->fd = fd; + list_add_tail(&irq_entry->list, &active_fds); + maybe_sigio_broken(fd); } -} - -/* - * Walk the IRQ list and get the descriptor for our FD - */ -static struct irq_entry *get_irq_entry_by_fd(int fd) -{ - struct irq_entry *walk = active_fds; + irq_entry->reg[type].id = dev_id; + irq_entry->reg[type].irq = irq; + irq_entry->reg[type].active = true; + irq_entry->reg[type].events = events; - while (walk != NULL) { - if (walk->fd == fd) - return walk; - walk = walk->next; +#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT + if (um_irq_timetravel_handler_used()) { + irq_entry->reg[type].timetravel_handler = timetravel_handler; + irq_entry->reg[type].event.fn = irq_event_handler; } - return NULL; -} +#endif + WARN_ON(!update_irq_entry(irq_entry)); + err = 0; +out_unlock: + raw_spin_unlock_irqrestore(&irq_lock, flags); +out: + kfree(to_free); + return err; +} /* - * Walk the IRQ list and dispose of an entry for a specific - * device, fd and number. Note - if sharing an IRQ for read - * and writefor the same FD it will be disposed in either case. - * If this behaviour is undesirable use different IRQ ids. + * Remove the entry or entries for a specific FD, if you + * don't want to remove all the possible entries then use + * um_free_irq() or deactivate_fd() instead. */ - -#define IGNORE_IRQ 1 -#define IGNORE_DEV (1<<1) - -static void do_free_by_irq_and_dev( - struct irq_entry *irq_entry, - unsigned int irq, - void *dev, - int flags -) -{ - int i; - struct irq_fd *to_free; - - for (i = 0; i < MAX_IRQ_TYPE ; i++) { - if (irq_entry->irq_array[i] != NULL) { - if ( - ((flags & IGNORE_IRQ) || - (irq_entry->irq_array[i]->irq == irq)) && - ((flags & IGNORE_DEV) || - (irq_entry->irq_array[i]->id == dev)) - ) { - /* Turn off any IO on this fd - allows us to - * avoid locking the IRQ loop - */ - os_del_epoll_fd(irq_entry->fd); - to_free = irq_entry->irq_array[i]; - irq_entry->irq_array[i] = NULL; - assign_epoll_events_to_irq(irq_entry); - if (to_free->active) - to_free->purge = true; - else - kfree(to_free); - } - } - } -} - void free_irq_by_fd(int fd) { struct irq_entry *to_free; unsigned long flags; - spin_lock_irqsave(&irq_lock, flags); + raw_spin_lock_irqsave(&irq_lock, flags); to_free = get_irq_entry_by_fd(fd); - if (to_free != NULL) { - do_free_by_irq_and_dev( - to_free, - -1, - NULL, - IGNORE_IRQ | IGNORE_DEV - ); - } - garbage_collect_irq_entries(); - spin_unlock_irqrestore(&irq_lock, flags); + remove_irq_entry(to_free, true); + raw_spin_unlock_irqrestore(&irq_lock, flags); + kfree(to_free); } EXPORT_SYMBOL(free_irq_by_fd); static void free_irq_by_irq_and_dev(unsigned int irq, void *dev) { - struct irq_entry *to_free; + struct irq_entry *entry, *to_free = NULL; unsigned long flags; - spin_lock_irqsave(&irq_lock, flags); - to_free = active_fds; - while (to_free != NULL) { - do_free_by_irq_and_dev( - to_free, - irq, - dev, - 0 - ); - to_free = to_free->next; + raw_spin_lock_irqsave(&irq_lock, flags); + list_for_each_entry(entry, &active_fds, list) { + enum um_irq_type i; + + for (i = 0; i < NUM_IRQ_TYPES; i++) { + struct irq_reg *reg = &entry->reg[i]; + + if (!reg->events) + continue; + if (reg->irq != irq) + continue; + if (reg->id != dev) + continue; + + os_del_epoll_fd(entry->fd); + reg->events = 0; + to_free = update_or_remove_irq_entry(entry); + goto out; + } } - garbage_collect_irq_entries(); - spin_unlock_irqrestore(&irq_lock, flags); +out: + raw_spin_unlock_irqrestore(&irq_lock, flags); + kfree(to_free); } - void deactivate_fd(int fd, int irqnum) { - struct irq_entry *to_free; + struct irq_entry *entry; unsigned long flags; + enum um_irq_type i; os_del_epoll_fd(fd); - spin_lock_irqsave(&irq_lock, flags); - to_free = get_irq_entry_by_fd(fd); - if (to_free != NULL) { - do_free_by_irq_and_dev( - to_free, - irqnum, - NULL, - IGNORE_DEV - ); + + raw_spin_lock_irqsave(&irq_lock, flags); + entry = get_irq_entry_by_fd(fd); + if (!entry) + goto out; + + for (i = 0; i < NUM_IRQ_TYPES; i++) { + if (!entry->reg[i].events) + continue; + if (entry->reg[i].irq == irqnum) + entry->reg[i].events = 0; } - garbage_collect_irq_entries(); - spin_unlock_irqrestore(&irq_lock, flags); + + entry = update_or_remove_irq_entry(entry); +out: + raw_spin_unlock_irqrestore(&irq_lock, flags); + kfree(entry); + ignore_sigio_fd(fd); } EXPORT_SYMBOL(deactivate_fd); @@ -384,24 +449,17 @@ EXPORT_SYMBOL(deactivate_fd); */ int deactivate_all_fds(void) { - struct irq_entry *to_free; + struct irq_entry *entry; /* Stop IO. The IRQ loop has no lock so this is our * only way of making sure we are safe to dispose * of all IRQ handlers */ os_set_ioignore(); - to_free = active_fds; - while (to_free != NULL) { - do_free_by_irq_and_dev( - to_free, - -1, - NULL, - IGNORE_IRQ | IGNORE_DEV - ); - to_free = to_free->next; - } - /* don't garbage collect - we can no longer call kfree() here */ + + /* we can no longer call kfree() here so just deactivate */ + list_for_each_entry(entry, &active_fds, list) + os_del_epoll_fd(entry->fd); os_close_epoll_fd(); return 0; } @@ -421,31 +479,181 @@ unsigned int do_IRQ(int irq, struct uml_pt_regs *regs) return 1; } -void um_free_irq(unsigned int irq, void *dev) +void um_free_irq(int irq, void *dev) { + if (WARN(irq < 0 || irq > UM_LAST_SIGNAL_IRQ, + "freeing invalid irq %d", irq)) + return; + free_irq_by_irq_and_dev(irq, dev); free_irq(irq, dev); + clear_bit(irq, irqs_allocated); } EXPORT_SYMBOL(um_free_irq); -int um_request_irq(unsigned int irq, int fd, int type, - irq_handler_t handler, - unsigned long irqflags, const char * devname, - void *dev_id) +static int +_um_request_irq(int irq, int fd, enum um_irq_type type, + irq_handler_t handler, unsigned long irqflags, + const char *devname, void *dev_id, + void (*timetravel_handler)(int, int, void *, + struct time_travel_event *)) { int err; + if (irq == UM_IRQ_ALLOC) { + int i; + + for (i = UM_FIRST_DYN_IRQ; i < NR_IRQS; i++) { + if (!test_and_set_bit(i, irqs_allocated)) { + irq = i; + break; + } + } + } + + if (irq < 0) + return -ENOSPC; + if (fd != -1) { - err = activate_fd(irq, fd, type, dev_id); + err = activate_fd(irq, fd, type, dev_id, timetravel_handler); if (err) - return err; + goto error; } - return request_irq(irq, handler, irqflags, devname, dev_id); + err = request_irq(irq, handler, irqflags, devname, dev_id); + if (err < 0) + goto error; + + return irq; +error: + clear_bit(irq, irqs_allocated); + return err; } +int um_request_irq(int irq, int fd, enum um_irq_type type, + irq_handler_t handler, unsigned long irqflags, + const char *devname, void *dev_id) +{ + return _um_request_irq(irq, fd, type, handler, irqflags, + devname, dev_id, NULL); +} EXPORT_SYMBOL(um_request_irq); +#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT +int um_request_irq_tt(int irq, int fd, enum um_irq_type type, + irq_handler_t handler, unsigned long irqflags, + const char *devname, void *dev_id, + void (*timetravel_handler)(int, int, void *, + struct time_travel_event *)) +{ + return _um_request_irq(irq, fd, type, handler, irqflags, + devname, dev_id, timetravel_handler); +} +EXPORT_SYMBOL(um_request_irq_tt); + +void sigio_run_timetravel_handlers(void) +{ + _sigio_handler(NULL, true); +} +#endif + +#ifdef CONFIG_PM_SLEEP +void um_irqs_suspend(void) +{ + struct irq_entry *entry; + unsigned long flags; + + irqs_suspended = true; + + raw_spin_lock_irqsave(&irq_lock, flags); + list_for_each_entry(entry, &active_fds, list) { + enum um_irq_type t; + bool clear = true; + + for (t = 0; t < NUM_IRQ_TYPES; t++) { + if (!entry->reg[t].events) + continue; + + /* + * For the SIGIO_WRITE_IRQ, which is used to handle the + * SIGIO workaround thread, we need special handling: + * enable wake for it itself, but below we tell it about + * any FDs that should be suspended. + */ + if (entry->reg[t].wakeup || + entry->reg[t].irq == SIGIO_WRITE_IRQ +#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT + || entry->reg[t].timetravel_handler +#endif + ) { + clear = false; + break; + } + } + + if (clear) { + entry->suspended = true; + os_clear_fd_async(entry->fd); + entry->sigio_workaround = + !__ignore_sigio_fd(entry->fd); + } + } + raw_spin_unlock_irqrestore(&irq_lock, flags); +} + +void um_irqs_resume(void) +{ + struct irq_entry *entry; + unsigned long flags; + + + raw_spin_lock_irqsave(&irq_lock, flags); + list_for_each_entry(entry, &active_fds, list) { + if (entry->suspended) { + int err = os_set_fd_async(entry->fd); + + WARN(err < 0, "os_set_fd_async returned %d\n", err); + entry->suspended = false; + + if (entry->sigio_workaround) { + err = __add_sigio_fd(entry->fd); + WARN(err < 0, "add_sigio_returned %d\n", err); + } + } + } + raw_spin_unlock_irqrestore(&irq_lock, flags); + + irqs_suspended = false; + send_sigio_to_self(); +} + +static int normal_irq_set_wake(struct irq_data *d, unsigned int on) +{ + struct irq_entry *entry; + unsigned long flags; + + raw_spin_lock_irqsave(&irq_lock, flags); + list_for_each_entry(entry, &active_fds, list) { + enum um_irq_type t; + + for (t = 0; t < NUM_IRQ_TYPES; t++) { + if (!entry->reg[t].events) + continue; + + if (entry->reg[t].irq != d->irq) + continue; + entry->reg[t].wakeup = on; + goto unlock; + } + } +unlock: + raw_spin_unlock_irqrestore(&irq_lock, flags); + return 0; +} +#else +#define normal_irq_set_wake NULL +#endif + /* * irq_chip must define at least enable/disable and ack when * the edge handler is used. @@ -454,7 +662,7 @@ static void dummy(struct irq_data *d) { } -/* This is used for everything else than the timer. */ +/* This is used for everything other than the timer. */ static struct irq_chip normal_irq_type = { .name = "SIGIO", .irq_disable = dummy, @@ -462,10 +670,11 @@ static struct irq_chip normal_irq_type = { .irq_ack = dummy, .irq_mask = dummy, .irq_unmask = dummy, + .irq_set_wake = normal_irq_set_wake, }; -static struct irq_chip SIGVTALRM_irq_type = { - .name = "SIGVTALRM", +static struct irq_chip alarm_irq_type = { + .name = "SIGALRM", .irq_disable = dummy, .irq_enable = dummy, .irq_ack = dummy, @@ -477,123 +686,43 @@ void __init init_IRQ(void) { int i; - irq_set_chip_and_handler(TIMER_IRQ, &SIGVTALRM_irq_type, handle_edge_irq); - + irq_set_chip_and_handler(TIMER_IRQ, &alarm_irq_type, handle_percpu_irq); - for (i = 1; i <= LAST_IRQ; i++) + for (i = 1; i < UM_LAST_SIGNAL_IRQ; i++) irq_set_chip_and_handler(i, &normal_irq_type, handle_edge_irq); /* Initialize EPOLL Loop */ os_setup_epoll(); } -/* - * IRQ stack entry and exit: - * - * Unlike i386, UML doesn't receive IRQs on the normal kernel stack - * and switch over to the IRQ stack after some preparation. We use - * sigaltstack to receive signals on a separate stack from the start. - * These two functions make sure the rest of the kernel won't be too - * upset by being on a different stack. The IRQ stack has a - * thread_info structure at the bottom so that current et al continue - * to work. - * - * to_irq_stack copies the current task's thread_info to the IRQ stack - * thread_info and sets the tasks's stack to point to the IRQ stack. - * - * from_irq_stack copies the thread_info struct back (flags may have - * been modified) and resets the task's stack pointer. - * - * Tricky bits - - * - * What happens when two signals race each other? UML doesn't block - * signals with sigprocmask, SA_DEFER, or sa_mask, so a second signal - * could arrive while a previous one is still setting up the - * thread_info. - * - * There are three cases - - * The first interrupt on the stack - sets up the thread_info and - * handles the interrupt - * A nested interrupt interrupting the copying of the thread_info - - * can't handle the interrupt, as the stack is in an unknown state - * A nested interrupt not interrupting the copying of the - * thread_info - doesn't do any setup, just handles the interrupt - * - * The first job is to figure out whether we interrupted stack setup. - * This is done by xchging the signal mask with thread_info->pending. - * If the value that comes back is zero, then there is no setup in - * progress, and the interrupt can be handled. If the value is - * non-zero, then there is stack setup in progress. In order to have - * the interrupt handled, we leave our signal in the mask, and it will - * be handled by the upper handler after it has set up the stack. - * - * Next is to figure out whether we are the outer handler or a nested - * one. As part of setting up the stack, thread_info->real_thread is - * set to non-NULL (and is reset to NULL on exit). This is the - * nesting indicator. If it is non-NULL, then the stack is already - * set up and the handler can run. - */ - -static unsigned long pending_mask; - -unsigned long to_irq_stack(unsigned long *mask_out) +int __init arch_probe_nr_irqs(void) { - struct thread_info *ti; - unsigned long mask, old; - int nested; - - mask = xchg(&pending_mask, *mask_out); - if (mask != 0) { - /* - * If any interrupts come in at this point, we want to - * make sure that their bits aren't lost by our - * putting our bit in. So, this loop accumulates bits - * until xchg returns the same value that we put in. - * When that happens, there were no new interrupts, - * and pending_mask contains a bit for each interrupt - * that came in. - */ - old = *mask_out; - do { - old |= mask; - mask = xchg(&pending_mask, old); - } while (mask != old); - return 1; - } - - ti = current_thread_info(); - nested = (ti->real_thread != NULL); - if (!nested) { - struct task_struct *task; - struct thread_info *tti; - - task = cpu_tasks[ti->cpu].task; - tti = task_thread_info(task); - - *ti = *tti; - ti->real_thread = tti; - task->stack = ti; - } - - mask = xchg(&pending_mask, 0); - *mask_out |= mask | nested; - return 0; + return NR_IRQS; } -unsigned long from_irq_stack(int nested) +void sigchld_handler(int sig, struct siginfo *unused_si, + struct uml_pt_regs *regs, void *mc) { - struct thread_info *ti, *to; - unsigned long mask; + do_IRQ(SIGCHLD_IRQ, regs); +} - ti = current_thread_info(); +/* + * /proc/interrupts printing for arch specific interrupts + */ +int arch_show_interrupts(struct seq_file *p, int prec) +{ +#if IS_ENABLED(CONFIG_SMP) + int cpu; - pending_mask = 1; + seq_printf(p, "%*s: ", prec, "RES"); + for_each_online_cpu(cpu) + seq_printf(p, "%10u ", irq_stats(cpu)->irq_resched_count); + seq_puts(p, " Rescheduling interrupts\n"); - to = ti->real_thread; - current->stack = to; - ti->real_thread = NULL; - *to = *ti; + seq_printf(p, "%*s: ", prec, "CAL"); + for_each_online_cpu(cpu) + seq_printf(p, "%10u ", irq_stats(cpu)->irq_call_count); + seq_puts(p, " Function call interrupts\n"); +#endif - mask = xchg(&pending_mask, 0); - return mask & ~1; + return 0; } - |