diff options
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/drivers/chan_kern.c | 53 | ||||
| -rw-r--r-- | arch/um/drivers/line.c | 2 | ||||
| -rw-r--r-- | arch/um/drivers/random.c | 11 | ||||
| -rw-r--r-- | arch/um/drivers/ubd_kern.c | 4 | ||||
| -rw-r--r-- | arch/um/include/shared/irq_user.h | 12 | ||||
| -rw-r--r-- | arch/um/include/shared/os.h | 17 | ||||
| -rw-r--r-- | arch/um/kernel/irq.c | 460 | ||||
| -rw-r--r-- | arch/um/os-Linux/irq.c | 202 |
8 files changed, 444 insertions, 317 deletions
diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c index acbe6c6..05588f9 100644 --- a/arch/um/drivers/chan_kern.c +++ b/arch/um/drivers/chan_kern.c @@ -171,56 +171,19 @@ int enable_chan(struct line *line) return err; } -/* Items are added in IRQ context, when free_irq can't be called, and - * removed in process context, when it can. - * This handles interrupt sources which disappear, and which need to - * be permanently disabled. This is discovered in IRQ context, but - * the freeing of the IRQ must be done later. - */ -static DEFINE_SPINLOCK(irqs_to_free_lock); -static LIST_HEAD(irqs_to_free); - -void free_irqs(void) -{ - struct chan *chan; - LIST_HEAD(list); - struct list_head *ele; - unsigned long flags; - - spin_lock_irqsave(&irqs_to_free_lock, flags); - list_splice_init(&irqs_to_free, &list); - spin_unlock_irqrestore(&irqs_to_free_lock, flags); - - list_for_each(ele, &list) { - chan = list_entry(ele, struct chan, free_list); - - if (chan->input && chan->enabled) - um_free_irq(chan->line->driver->read_irq, chan); - if (chan->output && chan->enabled) - um_free_irq(chan->line->driver->write_irq, chan); - chan->enabled = 0; - } -} - static void close_one_chan(struct chan *chan, int delay_free_irq) { - unsigned long flags; - if (!chan->opened) return; - if (delay_free_irq) { - spin_lock_irqsave(&irqs_to_free_lock, flags); - list_add(&chan->free_list, &irqs_to_free); - spin_unlock_irqrestore(&irqs_to_free_lock, flags); - } - else { - if (chan->input && chan->enabled) - um_free_irq(chan->line->driver->read_irq, chan); - if (chan->output && chan->enabled) - um_free_irq(chan->line->driver->write_irq, chan); - chan->enabled = 0; - } + /* we can safely call free now - it will be marked + * as free and freed once the IRQ stopped processing + */ + if (chan->input && chan->enabled) + um_free_irq(chan->line->driver->read_irq, chan); + if (chan->output && chan->enabled) + um_free_irq(chan->line->driver->write_irq, chan); + chan->enabled = 0; if (chan->ops->close != NULL) (*chan->ops->close)(chan->fd, chan->data); diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c index 366e57f..8d80b27 100644 --- a/arch/um/drivers/line.c +++ b/arch/um/drivers/line.c @@ -284,7 +284,7 @@ int line_setup_irq(int fd, int input, int output, struct line *line, void *data) if (err) return err; if (output) - err = um_request_irq(driver->write_irq, fd, IRQ_WRITE, + err = um_request_irq(driver->write_irq, fd, IRQ_NONE, line_write_interrupt, IRQF_SHARED, driver->write_irq_name, data); return err; diff --git a/arch/um/drivers/random.c b/arch/um/drivers/random.c index 37c51a6..778a0e5 100644 --- a/arch/um/drivers/random.c +++ b/arch/um/drivers/random.c @@ -13,6 +13,7 @@ #include <linux/miscdevice.h> #include <linux/delay.h> #include <linux/uaccess.h> +#include <init.h> #include <irq_kern.h> #include <os.h> @@ -154,7 +155,14 @@ err_out_cleanup_hw: /* * rng_cleanup - shutdown RNG module */ -static void __exit rng_cleanup (void) + +static void cleanup(void) +{ + free_irq_by_fd(random_fd); + os_close_file(random_fd); +} + +static void __exit rng_cleanup(void) { os_close_file(random_fd); misc_deregister (&rng_miscdev); @@ -162,6 +170,7 @@ static void __exit rng_cleanup (void) module_init (rng_init); module_exit (rng_cleanup); +__uml_exitcall(cleanup); MODULE_DESCRIPTION("UML Host Random Number Generator (RNG) driver"); MODULE_LICENSE("GPL"); diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index b55fe9b..d4e8c49 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -1587,11 +1587,11 @@ int io_thread(void *arg) do { res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written, n); - if (res > 0) { + if (res >= 0) { written += res; } else { if (res != -EAGAIN) { - printk("io_thread - read failed, fd = %d, " + printk("io_thread - write failed, fd = %d, " "err = %d\n", kernel_fd, -n); } } diff --git a/arch/um/include/shared/irq_user.h b/arch/um/include/shared/irq_user.h index df56330..a7a6120 100644 --- a/arch/um/include/shared/irq_user.h +++ b/arch/um/include/shared/irq_user.h @@ -7,6 +7,7 @@ #define __IRQ_USER_H__ #include <sysdep/ptrace.h> +#include <stdbool.h> struct irq_fd { struct irq_fd *next; @@ -15,10 +16,17 @@ struct irq_fd { int type; int irq; int events; - int current_events; + bool active; + bool pending; + bool purge; }; -enum { IRQ_READ, IRQ_WRITE }; +#define IRQ_READ 0 +#define IRQ_WRITE 1 +#define IRQ_NONE 2 +#define MAX_IRQ_TYPE (IRQ_NONE + 1) + + struct siginfo; extern void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs); diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h index d8ddaf9..048ae37 100644 --- a/arch/um/include/shared/os.h +++ b/arch/um/include/shared/os.h @@ -290,15 +290,16 @@ extern void halt_skas(void); extern void reboot_skas(void); /* irq.c */ -extern int os_waiting_for_events(struct irq_fd *active_fds); -extern int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds); -extern void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg, - struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2); -extern void os_free_irq_later(struct irq_fd *active_fds, - int irq, void *dev_id); -extern int os_get_pollfd(int i); -extern void os_set_pollfd(int i, int fd); +extern int os_waiting_for_events_epoll(void); +extern void *os_epoll_get_data_pointer(int index); +extern int os_epoll_triggered(int index, int events); +extern int os_event_mask(int irq_type); +extern int os_setup_epoll(void); +extern int os_add_epoll_fd(int events, int fd, void *data); +extern int os_mod_epoll_fd(int events, int fd, void *data); +extern int os_del_epoll_fd(int fd); extern void os_set_ioignore(void); +extern void os_close_epoll_fd(void); /* sigio.c */ extern int add_sigio_fd(int fd); diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c index 23cb935..980148d 100644 --- a/arch/um/kernel/irq.c +++ b/arch/um/kernel/irq.c @@ -1,4 +1,6 @@ /* + * Copyright (C) 2017 - Cambridge Greys Ltd + * Copyright (C) 2011 - 2014 Cisco Systems Inc * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Licensed under the GPL * Derived (i.e. mostly copied) from arch/i386/kernel/irq.c: @@ -16,243 +18,361 @@ #include <as-layout.h> #include <kern_util.h> #include <os.h> +#include <irq_user.h> -/* - * This list is accessed under irq_lock, except in sigio_handler, - * where it is safe from being modified. IRQ handlers won't change it - - * if an IRQ source has vanished, it will be freed by free_irqs just - * before returning from sigio_handler. That will process a separate - * list of irqs to free, with its own locking, coming back here to - * remove list elements, taking the irq_lock to do so. + +/* 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 - + * one entry per IRQ type */ -static struct irq_fd *active_fds = NULL; -static struct irq_fd **last_irq_ptr = &active_fds; -extern void free_irqs(void); +struct irq_entry { + struct irq_entry *next; + int fd; + struct irq_fd *irq_array[MAX_IRQ_TYPE + 1]; +}; + +static struct irq_entry *active_fds; + +static DEFINE_SPINLOCK(irq_lock); + +static void irq_io_loop(struct irq_fd *irq, struct uml_pt_regs *regs) +{ +/* + * irq->active guards against reentry + * irq->pending accumulates pending requests + * if pending is raised the irq_handler is re-run + * until pending is cleared + */ + 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; + } else { + irq->pending = true; + } +} void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs) { - struct irq_fd *irq_fd; - int n; + struct irq_entry *irq_entry; + struct irq_fd *irq; + + int n, i, j; while (1) { - n = os_waiting_for_events(active_fds); + /* This is now lockless - epoll keeps back-referencesto the irqs + * which have trigger it so there is no need to walk the irq + * list and lock it every time. We avoid locking by turning off + * IO for a specific fd by executing os_del_epoll_fd(fd) before + * we do any changes to the actual data structures + */ + n = os_waiting_for_events_epoll(); + if (n <= 0) { if (n == -EINTR) continue; - else break; + else + break; } - for (irq_fd = active_fds; irq_fd != NULL; - irq_fd = irq_fd->next) { - if (irq_fd->current_events != 0) { - irq_fd->current_events = 0; - do_IRQ(irq_fd->irq, 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); + } } } } +} + +static int assign_epoll_events_to_irq(struct irq_entry *irq_entry) +{ + int i; + int events = 0; + struct irq_fd *irq; - free_irqs(); + 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); } -static DEFINE_SPINLOCK(irq_lock); + static int activate_fd(int irq, int fd, int type, void *dev_id) { - struct pollfd *tmp_pfd; - struct irq_fd *new_fd, *irq_fd; + struct irq_fd *new_fd; + struct irq_entry *irq_entry; + int i, err, events; unsigned long flags; - int events, err, n; err = os_set_fd_async(fd); if (err < 0) goto out; - err = -ENOMEM; - new_fd = kmalloc(sizeof(struct irq_fd), GFP_KERNEL); - if (new_fd == NULL) - goto out; + spin_lock_irqsave(&irq_lock, flags); - if (type == IRQ_READ) - events = UM_POLLIN | UM_POLLPRI; - else events = UM_POLLOUT; - *new_fd = ((struct irq_fd) { .next = NULL, - .id = dev_id, - .fd = fd, - .type = type, - .irq = irq, - .events = events, - .current_events = 0 } ); + /* Check if we have an entry for this fd */ err = -EBUSY; - spin_lock_irqsave(&irq_lock, flags); - for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) { - if ((irq_fd->fd == fd) && (irq_fd->type == type)) { - printk(KERN_ERR "Registering fd %d twice\n", fd); - printk(KERN_ERR "Irqs : %d, %d\n", irq_fd->irq, irq); - printk(KERN_ERR "Ids : 0x%p, 0x%p\n", irq_fd->id, - dev_id); + for (irq_entry = active_fds; + irq_entry != NULL; irq_entry = irq_entry->next) { + if (irq_entry->fd == fd) + break; + } + + 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; } - if (type == IRQ_WRITE) - fd = -1; - - tmp_pfd = NULL; - n = 0; + /* Check if we are trying to re-register an interrupt for a + * particular fd + */ - while (1) { - n = os_create_pollfd(fd, events, tmp_pfd, n); - if (n == 0) - break; + 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 */ + + err = -ENOMEM; + new_fd = kmalloc(sizeof(struct irq_fd), GFP_ATOMIC); + if (new_fd == NULL) + goto out_unlock; - /* - * n > 0 - * It means we couldn't put new pollfd to current pollfds - * and tmp_fds is NULL or too small for new pollfds array. - * Needed size is equal to n as minimum. - * - * Here we have to drop the lock in order to call - * kmalloc, which might sleep. - * If something else came in and changed the pollfds array - * so we will not be able to put new pollfd struct to pollfds - * then we free the buffer tmp_fds and try again. + 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 */ - spin_unlock_irqrestore(&irq_lock, flags); - kfree(tmp_pfd); - - tmp_pfd = kmalloc(n, GFP_KERNEL); - if (tmp_pfd == NULL) - goto out_kfree; - - spin_lock_irqsave(&irq_lock, flags); + os_del_epoll_fd(irq_entry->fd); + irq_entry->irq_array[type] = new_fd; } - *last_irq_ptr = new_fd; - last_irq_ptr = &new_fd->next; - + /* Turn back IO on with the correct (new) IO event mask */ + assign_epoll_events_to_irq(irq_entry); spin_unlock_irqrestore(&irq_lock, flags); - - /* - * This calls activate_fd, so it has to be outside the critical - * section. - */ - maybe_sigio_broken(fd, (type == IRQ_READ)); + maybe_sigio_broken(fd, (type != IRQ_NONE)); return 0; - - out_unlock: +out_unlock: spin_unlock_irqrestore(&irq_lock, flags); - out_kfree: - kfree(new_fd); - out: +out: return err; } -static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg) +/* + * Walk the IRQ list and dispose of any unused entries. + * Should be done under irq_lock. + */ + +static void garbage_collect_irq_entries(void) { - unsigned long flags; + int i; + bool reap; + struct irq_entry *walk; + struct irq_entry *previous = NULL; + struct irq_entry *to_free; - spin_lock_irqsave(&irq_lock, flags); - os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr); - spin_unlock_irqrestore(&irq_lock, 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; + } + } + if (reap) { + if (previous == NULL) + active_fds = walk->next; + else + previous->next = walk->next; + to_free = walk; + } else { + to_free = NULL; + } + walk = walk->next; + if (to_free != NULL) + kfree(to_free); + } } -struct irq_and_dev { - int irq; - void *dev; -}; +/* + * Walk the IRQ list and get the descriptor for our FD + */ -static int same_irq_and_dev(struct irq_fd *irq, void *d) +static struct irq_entry *get_irq_entry_by_fd(int fd) { - struct irq_and_dev *data = d; + struct irq_entry *walk = active_fds; - return ((irq->irq == data->irq) && (irq->id == data->dev)); + while (walk != NULL) { + if (walk->fd == fd) + return walk; + walk = walk->next; + } + return NULL; } -static void free_irq_by_irq_and_dev(unsigned int irq, void *dev) -{ - struct irq_and_dev data = ((struct irq_and_dev) { .irq = irq, - .dev = dev }); - free_irq_by_cb(same_irq_and_dev, &data); -} +/* + * 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. + */ -static int same_fd(struct irq_fd *irq, void *fd) -{ - return (irq->fd == *((int *)fd)); -} +#define IGNORE_IRQ 1 +#define IGNORE_DEV (1<<1) -void free_irq_by_fd(int fd) +static void do_free_by_irq_and_dev( + struct irq_entry *irq_entry, + unsigned int irq, + void *dev, + int flags +) { - free_irq_by_cb(same_fd, &fd); + 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); + } + } + } } -/* Must be called with irq_lock held */ -static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out) +void free_irq_by_fd(int fd) { - struct irq_fd *irq; - int i = 0; - int fdi; + struct irq_entry *to_free; + unsigned long flags; - for (irq = active_fds; irq != NULL; irq = irq->next) { - if ((irq->fd == fd) && (irq->irq == irqnum)) - break; - i++; - } - if (irq == NULL) { - printk(KERN_ERR "find_irq_by_fd doesn't have descriptor %d\n", - fd); - goto out; - } - fdi = os_get_pollfd(i); - if ((fdi != -1) && (fdi != fd)) { - printk(KERN_ERR "find_irq_by_fd - mismatch between active_fds " - "and pollfds, fd %d vs %d, need %d\n", irq->fd, - fdi, fd); - irq = NULL; - goto out; + 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 + ); } - *index_out = i; - out: - return irq; + garbage_collect_irq_entries(); + spin_unlock_irqrestore(&irq_lock, flags); } -void reactivate_fd(int fd, int irqnum) +static void free_irq_by_irq_and_dev(unsigned int irq, void *dev) { - struct irq_fd *irq; + struct irq_entry *to_free; unsigned long flags; - int i; spin_lock_irqsave(&irq_lock, flags); - irq = find_irq_by_fd(fd, irqnum, &i); - if (irq == NULL) { - spin_unlock_irqrestore(&irq_lock, flags); - return; + to_free = active_fds; + while (to_free != NULL) { + do_free_by_irq_and_dev( + to_free, + irq, + dev, + 0 + ); + to_free = to_free->next; } - os_set_pollfd(i, irq->fd); + garbage_collect_irq_entries(); spin_unlock_irqrestore(&irq_lock, flags); +} - add_sigio_fd(fd); + +void reactivate_fd(int fd, int irqnum) +{ + /** NOP - we do auto-EOI now **/ } void deactivate_fd(int fd, int irqnum) { - struct irq_fd *irq; + struct irq_entry *to_free; unsigned long flags; - int i; + os_del_epoll_fd(fd); spin_lock_irqsave(&irq_lock, flags); - irq = find_irq_by_fd(fd, irqnum, &i); - if (irq == NULL) { - spin_unlock_irqrestore(&irq_lock, flags); - return; + to_free = get_irq_entry_by_fd(fd); + if (to_free != NULL) { + do_free_by_irq_and_dev( + to_free, + irqnum, + NULL, + IGNORE_DEV + ); } - - os_set_pollfd(i, -1); + garbage_collect_irq_entries(); spin_unlock_irqrestore(&irq_lock, flags); - ignore_sigio_fd(fd); } EXPORT_SYMBOL(deactivate_fd); @@ -265,17 +385,28 @@ EXPORT_SYMBOL(deactivate_fd); */ int deactivate_all_fds(void) { - struct irq_fd *irq; - int err; + unsigned long flags; + struct irq_entry *to_free; - for (irq = active_fds; irq != NULL; irq = irq->next) { - err = os_clear_fd_async(irq->fd); - if (err) - return err; - } - /* If there is a signal already queued, after unblocking ignore it */ + spin_lock_irqsave(&irq_lock, flags); + /* 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; + } + garbage_collect_irq_entries(); + spin_unlock_irqrestore(&irq_lock, flags); + os_close_epoll_fd(); return 0; } @@ -353,8 +484,11 @@ void __init init_IRQ(void) irq_set_chip_and_handler(TIMER_IRQ, &SIGVTALRM_irq_type, handle_edge_irq); + for (i = 1; i < NR_IRQS; i++) irq_set_chip_and_handler(i, &normal_irq_type, handle_edge_irq); + /* Initialize EPOLL Loop */ + os_setup_epoll(); } /* diff --git a/arch/um/os-Linux/irq.c b/arch/um/os-Linux/irq.c index b9afb74..3658230 100644 --- a/arch/um/os-Linux/irq.c +++ b/arch/um/os-Linux/irq.c @@ -1,135 +1,147 @@ /* + * Copyright (C) 2017 - Cambridge Greys Ltd + * Copyright (C) 2011 - 2014 Cisco Systems Inc * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Licensed under the GPL */ #include <stdlib.h> #include <errno.h> -#include <poll.h> +#include <sys/epoll.h> #include <signal.h> #include <string.h> #include <irq_user.h> #include <os.h> #include <um_malloc.h> +/* Epoll support */ + +static int epollfd = -1; + +#define MAX_EPOLL_EVENTS 64 + +static struct epoll_event epoll_events[MAX_EPOLL_EVENTS]; + +/* Helper to return an Epoll data pointer from an epoll event structure. + * We need to keep this one on the userspace side to keep includes separate + */ + +void *os_epoll_get_data_pointer(int index) +{ + return epoll_events[index].data.ptr; +} + +/* Helper to compare events versus the events in the epoll structure. + * Same as above - needs to be on the userspace side + */ + + +int os_epoll_triggered(int index, int events) +{ + return epoll_events[index].events & events; +} +/* Helper to set the event mask. + * The event mask is opaque to the kernel side, because it does not have + * access to the right includes/defines for EPOLL constants. + */ + +int os_event_mask(int irq_type) +{ + if (irq_type == IRQ_READ) + return EPOLLIN | EPOLLPRI; + if (irq_type == IRQ_WRITE) + return EPOLLOUT; + return 0; +} + /* - * Locked by irq_lock in arch/um/kernel/irq.c. Changed by os_create_pollfd - * and os_free_irq_by_cb, which are called under irq_lock. + * Initial Epoll Setup */ -static struct pollfd *pollfds = NULL; -static int pollfds_num = 0; -static int pollfds_size = 0; +int os_setup_epoll(void) +{ + epollfd = epoll_create(MAX_EPOLL_EVENTS); + return epollfd; +} -int os_waiting_for_events(struct irq_fd *active_fds) +/* + * Helper to run the actual epoll_wait + */ +int os_waiting_for_events_epoll(void) { - struct irq_fd *irq_fd; - int i, n, err; + int n, err; - n = poll(pollfds, pollfds_num, 0); + n = epoll_wait(epollfd, + (struct epoll_event *) &epoll_events, MAX_EPOLL_EVENTS, 0); if (n < 0) { err = -errno; if (errno != EINTR) - printk(UM_KERN_ERR "os_waiting_for_events:" - " poll returned %d, errno = %d\n", n, errno); + printk( + UM_KERN_ERR "os_waiting_for_events:" + " epoll returned %d, error = %s\n", n, + strerror(errno) + ); return err; } - - if (n == 0) - return 0; - - irq_fd = active_fds; - - for (i = 0; i < pollfds_num; i++) { - if (pollfds[i].revents != 0) { - irq_fd->current_events = pollfds[i].revents; - pollfds[i].fd = -1; - } - irq_fd = irq_fd->next; - } return n; } -int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds) -{ - if (pollfds_num == pollfds_size) { - if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) { - /* return min size needed for new pollfds area */ - return (pollfds_size + 1) * sizeof(pollfds[0]); - } - - if (pollfds != NULL) { - memcpy(tmp_pfd, pollfds, - sizeof(pollfds[0]) * pollfds_size); - /* remove old pollfds */ - kfree(pollfds); - } - pollfds = tmp_pfd; - pollfds_size++; - } else - kfree(tmp_pfd); /* remove not used tmp_pfd */ - - pollfds[pollfds_num] = ((struct pollfd) { .fd = fd, - .events = events, - .revents = 0 }); - pollfds_num++; - - return 0; -} -void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg, - struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2) +/* + * Helper to add a fd to epoll + */ +int os_add_epoll_fd(int events, int fd, void *data) { - struct irq_fd **prev; - int i = 0; - - prev = &active_fds; - while (*prev != NULL) { - if ((*test)(*prev, arg)) { - struct irq_fd *old_fd = *prev; - if ((pollfds[i].fd != -1) && - (pollfds[i].fd != (*prev)->fd)) { - printk(UM_KERN_ERR "os_free_irq_by_cb - " - "mismatch between active_fds and " - "pollfds, fd %d vs %d\n", - (*prev)->fd, pollfds[i].fd); - goto out; - } - - pollfds_num--; - - /* - * This moves the *whole* array after pollfds[i] - * (though it doesn't spot as such)! - */ - memmove(&pollfds[i], &pollfds[i + 1], - (pollfds_num - i) * sizeof(pollfds[0])); - if (*last_irq_ptr2 == &old_fd->next) - *last_irq_ptr2 = prev; - - *prev = (*prev)->next; - if (old_fd->type == IRQ_WRITE) - ignore_sigio_fd(old_fd->fd); - kfree(old_fd); - continue; - } - prev = &(*prev)->next; - i++; - } - out: - return; + struct epoll_event event; + int result; + + event.data.ptr = data; + event.events = events | EPOLLET; + result = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event); + if ((result) && (errno == EEXIST)) + result = os_mod_epoll_fd(events, fd, data); + if (result) + printk("epollctl add err fd %d, %s\n", fd, strerror(errno)); + return result; } -int os_get_pollfd(int i) +/* + * Helper to mod the fd event mask and/or data backreference + */ +int os_mod_epoll_fd(int events, int fd, void *data) { - return pollfds[i].fd; + struct epoll_event event; + int result; + + event.data.ptr = data; + event.events = events; + result = epoll_ctl(epollfd, EPOLL_CTL_MOD, fd, &event); + if (result) + printk(UM_KERN_ERR + "epollctl mod err fd %d, %s\n", fd, strerror(errno)); + return result; } -void os_set_pollfd(int i, int fd) +/* + * Helper to delete the epoll fd + */ +int os_del_epoll_fd(int fd) { - pollfds[i].fd = fd; + struct epoll_event event; + int result; + /* This is quiet as we use this as IO ON/OFF - so it is often + * invoked on a non-existent fd + */ + result = epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, &event); + return result; } void os_set_ioignore(void) { signal(SIGIO, SIG_IGN); } + +void os_close_epoll_fd(void) +{ + /* Needed so we do not leak an fd when rebooting */ + os_close_file(epollfd); +} |
