X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fchar%2Fhvc_console.c;h=2b6a56b2bf35c78b53153d87b032c720b5b0b004;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=88cd858f74d0d12d9bfdcc255f5b36be0fac5068;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c index 88cd858f7..2b6a56b2b 100644 --- a/drivers/char/hvc_console.c +++ b/drivers/char/hvc_console.c @@ -22,6 +22,7 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include #include #include #include @@ -38,9 +39,10 @@ #include #include #include + #include -#include -#include + +#include "hvc_console.h" #define HVC_MAJOR 229 #define HVC_MINOR 0 @@ -54,23 +56,25 @@ #define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ /* - * The Linux TTY code does not support dynamic addition of tty derived devices - * so we need to know how many tty devices we might need when space is allocated - * for the tty device. Since this driver supports hotplug of vty adapters we - * need to make sure we have enough allocated. + * These sizes are most efficient for vio, because they are the + * native transfer size. We could make them selectable in the + * future to better deal with backends that want other buffer sizes. */ -#define HVC_ALLOC_TTY_ADAPTERS 8 +#define N_OUTBUF 16 +#define N_INBUF 16 + +#define __ALIGNED__ __attribute__((__aligned__(sizeof(long)))) static struct tty_driver *hvc_driver; +static struct task_struct *hvc_task; + +/* Picks up late kicks after list walk but before schedule() */ +static int hvc_kicked; + #ifdef CONFIG_MAGIC_SYSRQ static int sysrq_pressed; #endif -#define N_OUTBUF 16 -#define N_INBUF 16 - -#define __ALIGNED__ __attribute__((__aligned__(8))) - struct hvc_struct { spinlock_t lock; int index; @@ -80,11 +84,11 @@ struct hvc_struct { char outbuf[N_OUTBUF] __ALIGNED__; int n_outbuf; uint32_t vtermno; + struct hv_ops *ops; int irq_requested; int irq; struct list_head next; struct kobject kobj; /* ref count & hvc_struct lifetime */ - struct vio_dev *vdev; }; /* dynamic list of hvc_struct instances */ @@ -96,27 +100,186 @@ static struct list_head hvc_structs = LIST_HEAD_INIT(hvc_structs); */ static DEFINE_SPINLOCK(hvc_structs_lock); +/* + * This value is used to assign a tty->index value to a hvc_struct based + * upon order of exposure via hvc_probe(), when we can not match it to + * a console canidate registered with hvc_instantiate(). + */ +static int last_hvc = -1; + +/* + * Do not call this function with either the hvc_strucst_lock or the hvc_struct + * lock held. If successful, this function increments the kobject reference + * count against the target hvc_struct so it should be released when finished. + */ +struct hvc_struct *hvc_get_by_index(int index) +{ + struct hvc_struct *hp; + unsigned long flags; + + spin_lock(&hvc_structs_lock); + + list_for_each_entry(hp, &hvc_structs, next) { + spin_lock_irqsave(&hp->lock, flags); + if (hp->index == index) { + kobject_get(&hp->kobj); + spin_unlock_irqrestore(&hp->lock, flags); + spin_unlock(&hvc_structs_lock); + return hp; + } + spin_unlock_irqrestore(&hp->lock, flags); + } + hp = NULL; + + spin_unlock(&hvc_structs_lock); + return hp; +} + + /* * Initial console vtermnos for console API usage prior to full console * initialization. Any vty adapter outside this range will not have usable * console interfaces but can still be used as a tty device. This has to be * static because kmalloc will not work during early console init. */ -static uint32_t vtermnos[MAX_NR_HVC_CONSOLES]; +static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; +static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] = + {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1}; -/* Used for accounting purposes */ -static int num_vterms = 0; +/* + * Console APIs, NOT TTY. These APIs are available immediately when + * hvc_console_setup() finds adapters. + */ -static struct task_struct *hvc_task; +void hvc_console_print(struct console *co, const char *b, unsigned count) +{ + char c[N_OUTBUF] __ALIGNED__; + unsigned i = 0, n = 0; + int r, donecr = 0, index = co->index; + + /* Console access attempt outside of acceptable console range. */ + if (index >= MAX_NR_HVC_CONSOLES) + return; + + /* This console adapter was removed so it is not useable. */ + if (vtermnos[index] < 0) + return; + + while (count > 0 || i > 0) { + if (count > 0 && i < sizeof(c)) { + if (b[n] == '\n' && !donecr) { + c[i++] = '\r'; + donecr = 1; + } else { + c[i++] = b[n++]; + donecr = 0; + --count; + } + } else { + r = cons_ops[index]->put_chars(vtermnos[index], c, i); + if (r < 0) { + /* throw away chars on error */ + i = 0; + } else if (r > 0) { + i -= r; + if (i > 0) + memmove(c, c+r, i); + } + } + } +} + +static struct tty_driver *hvc_console_device(struct console *c, int *index) +{ + if (vtermnos[c->index] == -1) + return NULL; + + *index = c->index; + return hvc_driver; +} + +static int __init hvc_console_setup(struct console *co, char *options) +{ + if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES) + return -ENODEV; + + if (vtermnos[co->index] == -1) + return -ENODEV; + + return 0; +} + +struct console hvc_con_driver = { + .name = "hvc", + .write = hvc_console_print, + .device = hvc_console_device, + .setup = hvc_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +/* + * Early console initialization. Preceeds driver initialization. + * + * (1) we are first, and the user specified another driver + * -- index will remain -1 + * (2) we are first and the user specified no driver + * -- index will be set to 0, then we will fail setup. + * (3) we are first and the user specified our driver + * -- index will be set to user specified driver, and we will fail + * (4) we are after driver, and this initcall will register us + * -- if the user didn't specify a driver then the console will match + * + * Note that for cases 2 and 3, we will match later when the io driver + * calls hvc_instantiate() and call register again. + */ +static int __init hvc_console_init(void) +{ + register_console(&hvc_con_driver); + return 0; +} +console_initcall(hvc_console_init); /* - * This value is used to associate a tty->index value to a hvc_struct based - * upon order of exposure via hvc_probe(). + * hvc_instantiate() is an early console discovery method which locates + * consoles * prior to the vio subsystem discovering them. Hotplugged + * vty adapters do NOT get an hvc_instantiate() callback since they + * appear after early console init. */ -static int hvc_count = -1; +int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops) +{ + struct hvc_struct *hp; -/* Picks up late kicks after list walk but before schedule() */ -static int hvc_kicked; + if (index < 0 || index >= MAX_NR_HVC_CONSOLES) + return -1; + + if (vtermnos[index] != -1) + return -1; + + /* make sure no no tty has been registerd in this index */ + hp = hvc_get_by_index(index); + if (hp) { + kobject_put(&hp->kobj); + return -1; + } + + vtermnos[index] = vtermno; + cons_ops[index] = ops; + + /* reserve all indices upto and including this index */ + if (last_hvc < index) + last_hvc = index; + + /* if this index is what the user requested, then register + * now (setup won't fail at this point). It's ok to just + * call register again if previously .setup failed. + */ + if (index == hvc_con_driver.index) + register_console(&hvc_con_driver); + + return 0; +} +EXPORT_SYMBOL(hvc_instantiate); /* Wake the sleeping khvcd */ static void hvc_kick(void) @@ -125,13 +288,17 @@ static void hvc_kick(void) wake_up_process(hvc_task); } +static int hvc_poll(struct hvc_struct *hp); + /* * NOTE: This API isn't used if the console adapter doesn't support interrupts. * In this case the console is poll driven. */ static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance, struct pt_regs *regs) { - hvc_kick(); + /* if hvc_poll request a repoll, then kick the hvcd thread */ + if (hvc_poll(dev_instance)) + hvc_kick(); return IRQ_HANDLED; } @@ -140,34 +307,6 @@ static void hvc_unthrottle(struct tty_struct *tty) hvc_kick(); } -/* - * Do not call this function with either the hvc_strucst_lock or the hvc_struct - * lock held. If successful, this function increments the kobject reference - * count against the target hvc_struct so it should be released when finished. - */ -struct hvc_struct *hvc_get_by_index(int index) -{ - struct hvc_struct *hp; - unsigned long flags; - - spin_lock(&hvc_structs_lock); - - list_for_each_entry(hp, &hvc_structs, next) { - spin_lock_irqsave(&hp->lock, flags); - if (hp->index == index) { - kobject_get(&hp->kobj); - spin_unlock_irqrestore(&hp->lock, flags); - spin_unlock(&hvc_structs_lock); - return hp; - } - spin_unlock_irqrestore(&hp->lock, flags); - } - hp = NULL; - - spin_unlock(&hvc_structs_lock); - return hp; -} - /* * The TTY interface won't be used until after the vio layer has exposed the vty * adapter to the kernel. @@ -195,6 +334,8 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) } /* else count == 0 */ tty->driver_data = hp; + tty->low_latency = 1; /* Makes flushes to ldisc synchronous. */ + hp->tty = tty; /* Save for request_irq outside of spin_lock. */ irq = hp->irq; @@ -329,10 +470,12 @@ static void hvc_push(struct hvc_struct *hp) { int n; - n = hvc_put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); + n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); if (n <= 0) { - if (n == 0) + if (n == 0) { + hp->do_wakeup = 1; return; + } /* throw away output on error; this happens when there is no session connected to the vterm. */ hp->n_outbuf = 0; @@ -344,12 +487,19 @@ static void hvc_push(struct hvc_struct *hp) hp->do_wakeup = 1; } -static inline int __hvc_write_kernel(struct hvc_struct *hp, - const unsigned char *buf, int count) +static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) { + struct hvc_struct *hp = tty->driver_data; unsigned long flags; int rsize, written = 0; + /* This write was probably executed during a tty close. */ + if (!hp) + return -EPIPE; + + if (hp->count <= 0) + return -EIO; + spin_lock_irqsave(&hp->lock, flags); /* Push pending writes */ @@ -368,26 +518,8 @@ static inline int __hvc_write_kernel(struct hvc_struct *hp, } spin_unlock_irqrestore(&hp->lock, flags); - return written; -} -static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) -{ - struct hvc_struct *hp = tty->driver_data; - int written; - - /* This write was probably executed during a tty close. */ - if (!hp) - return -EPIPE; - - if (hp->count <= 0) - return -EIO; - - written = __hvc_write_kernel(hp, buf, count); - /* * Racy, but harmless, kick thread if there is still pending data. - * There really is nothing wrong with kicking the thread, even if there - * is no buffered data. */ if (hp->n_outbuf) hvc_kick(); @@ -457,9 +589,7 @@ static int hvc_poll(struct hvc_struct *hp) /* Read data if any */ for (;;) { - int count = N_INBUF; - if (count > (TTY_FLIPBUF_SIZE - tty->flip.count)) - count = TTY_FLIPBUF_SIZE - tty->flip.count; + int count = tty_buffer_request_room(tty, N_INBUF); /* If flip is full, just reschedule a later read */ if (count == 0) { @@ -467,44 +597,42 @@ static int hvc_poll(struct hvc_struct *hp) break; } - n = hvc_get_chars(hp->vtermno, buf, count); + n = hp->ops->get_chars(hp->vtermno, buf, count); if (n <= 0) { /* Hangup the tty when disconnected from host */ if (n == -EPIPE) { spin_unlock_irqrestore(&hp->lock, flags); tty_hangup(tty); spin_lock_irqsave(&hp->lock, flags); + } else if ( n == -EAGAIN ) { + /* + * Some back-ends can only ensure a certain min + * num of bytes read, which may be > 'count'. + * Let the tty clear the flip buff to make room. + */ + poll_mask |= HVC_POLL_READ; } break; } for (i = 0; i < n; ++i) { #ifdef CONFIG_MAGIC_SYSRQ - /* Handle the SysRq Hack */ - if (buf[i] == '\x0f') { /* ^O -- should support a sequence */ - sysrq_pressed = 1; - continue; - } else if (sysrq_pressed) { - handle_sysrq(buf[i], NULL, tty); - sysrq_pressed = 0; - continue; + if (hp->index == hvc_con_driver.index) { + /* Handle the SysRq Hack */ + /* XXX should support a sequence */ + if (buf[i] == '\x0f') { /* ^O */ + sysrq_pressed = 1; + continue; + } else if (sysrq_pressed) { + handle_sysrq(buf[i], NULL, tty); + sysrq_pressed = 0; + continue; + } } #endif /* CONFIG_MAGIC_SYSRQ */ tty_insert_flip_char(tty, buf[i], 0); } - if (tty->flip.count) - tty_schedule_flip(tty); - - /* - * Account for the total amount read in one loop, and if above - * 64 bytes, we do a quick schedule loop to let the tty grok the - * data and eventually throttle us. - */ read_total += n; - if (read_total >= 64) { - poll_mask |= HVC_POLL_QUICK; - break; - } } throttled: /* Wakeup write queue if necessary */ @@ -515,6 +643,9 @@ static int hvc_poll(struct hvc_struct *hp) bail: spin_unlock_irqrestore(&hp->lock, flags); + if (read_total) + tty_flip_buffer_push(tty); + return poll_mask; } @@ -542,7 +673,6 @@ int khvcd(void *unused) if (cpus_empty(cpus_in_xmon)) { spin_lock(&hvc_structs_lock); list_for_each_entry(hp, &hvc_structs, next) { - /*hp = list_entry(node, struct hvc_struct, * next); */ poll_mask |= hvc_poll(hp); } spin_unlock(&hvc_structs_lock); @@ -577,14 +707,6 @@ static struct tty_operations hvc_ops = { .chars_in_buffer = hvc_chars_in_buffer, }; -char hvc_driver_name[] = "hvc_console"; - -static struct vio_device_id hvc_driver_table[] __devinitdata= { - {"serial", "hvterm1"}, - { NULL, } -}; -MODULE_DEVICE_TABLE(vio, hvc_driver_table); - /* callback when the kboject ref count reaches zero. */ static void destroy_hvc_struct(struct kobject *kobj) { @@ -606,41 +728,52 @@ static struct kobj_type hvc_kobj_type = { .release = destroy_hvc_struct, }; -static int __devinit hvc_probe( - struct vio_dev *dev, - const struct vio_device_id *id) +struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int irq, + struct hv_ops *ops) { struct hvc_struct *hp; - - /* probed with invalid parameters. */ - if (!dev || !id) - return -EPERM; + int i; hp = kmalloc(sizeof(*hp), GFP_KERNEL); if (!hp) - return -ENOMEM; + return ERR_PTR(-ENOMEM); memset(hp, 0x00, sizeof(*hp)); - hp->vtermno = dev->unit_address; - hp->vdev = dev; - hp->vdev->dev.driver_data = hp; - hp->irq = dev->irq; + + hp->vtermno = vtermno; + hp->irq = irq; + hp->ops = ops; kobject_init(&hp->kobj); hp->kobj.ktype = &hvc_kobj_type; spin_lock_init(&hp->lock); spin_lock(&hvc_structs_lock); - hp->index = ++hvc_count; + + /* + * find index to use: + * see if this vterm id matches one registered for console. + */ + for (i=0; i < MAX_NR_HVC_CONSOLES; i++) + if (vtermnos[i] == hp->vtermno && + cons_ops[i] == hp->ops) + break; + + /* no matching slot, just use a counter */ + if (i >= MAX_NR_HVC_CONSOLES) + i = ++last_hvc; + + hp->index = i; + list_add_tail(&(hp->next), &hvc_structs); spin_unlock(&hvc_structs_lock); - return 0; + return hp; } +EXPORT_SYMBOL(hvc_alloc); -static int __devexit hvc_remove(struct vio_dev *dev) +int __devexit hvc_remove(struct hvc_struct *hp) { - struct hvc_struct *hp = dev->dev.driver_data; unsigned long flags; struct kobject *kobjp; struct tty_struct *tty; @@ -673,159 +806,58 @@ static int __devexit hvc_remove(struct vio_dev *dev) tty_hangup(tty); return 0; } - -static struct vio_driver hvc_vio_driver = { - .name = hvc_driver_name, - .id_table = hvc_driver_table, - .probe = hvc_probe, - .remove = hvc_remove, -}; +EXPORT_SYMBOL(hvc_remove); /* Driver initialization. Follow console initialization. This is where the TTY * interfaces start to become available. */ int __init hvc_init(void) { - int rc; + struct tty_driver *drv; - /* We need more than num_vterms adapters due to hotplug additions. */ - hvc_driver = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); - /* hvc_driver = alloc_tty_driver(num_vterms); */ - if (!hvc_driver) + /* We need more than hvc_count adapters due to hotplug additions. */ + drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); + if (!drv) return -ENOMEM; - hvc_driver->owner = THIS_MODULE; - hvc_driver->devfs_name = "hvc/"; - hvc_driver->driver_name = "hvc"; - hvc_driver->name = "hvc"; - hvc_driver->major = HVC_MAJOR; - hvc_driver->minor_start = HVC_MINOR; - hvc_driver->type = TTY_DRIVER_TYPE_SYSTEM; - hvc_driver->init_termios = tty_std_termios; - hvc_driver->flags = TTY_DRIVER_REAL_RAW; - tty_set_operations(hvc_driver, &hvc_ops); - - if (tty_register_driver(hvc_driver)) - panic("Couldn't register hvc console driver\n"); + drv->owner = THIS_MODULE; + drv->devfs_name = "hvc/"; + drv->driver_name = "hvc"; + drv->name = "hvc"; + drv->major = HVC_MAJOR; + drv->minor_start = HVC_MINOR; + drv->type = TTY_DRIVER_TYPE_SYSTEM; + drv->init_termios = tty_std_termios; + drv->flags = TTY_DRIVER_REAL_RAW; + tty_set_operations(drv, &hvc_ops); /* Always start the kthread because there can be hotplug vty adapters * added later. */ hvc_task = kthread_run(khvcd, NULL, "khvcd"); if (IS_ERR(hvc_task)) { panic("Couldn't create kthread for console.\n"); - put_tty_driver(hvc_driver); + put_tty_driver(drv); return -EIO; } - /* Register as a vio device to receive callbacks */ - rc = vio_register_driver(&hvc_vio_driver); + if (tty_register_driver(drv)) + panic("Couldn't register hvc console driver\n"); - return rc; + mb(); + hvc_driver = drv; + return 0; } +module_init(hvc_init); -/* This isn't particularily necessary due to this being a console driver but it - * is nice to be thorough */ +/* This isn't particularily necessary due to this being a console driver + * but it is nice to be thorough. + */ static void __exit hvc_exit(void) { kthread_stop(hvc_task); - vio_unregister_driver(&hvc_vio_driver); tty_unregister_driver(hvc_driver); /* return tty_struct instances allocated in hvc_init(). */ put_tty_driver(hvc_driver); + unregister_console(&hvc_con_driver); } - -/* - * Console APIs, NOT TTY. These APIs are available immediately when - * hvc_console_setup() finds adapters. - */ - -/* - * hvc_instantiate() is an early console discovery method which locates consoles - * prior to the vio subsystem discovering them. Hotplugged vty adapters do NOT - * get an hvc_instantiate() callback since the appear after early console init. - */ -int hvc_instantiate(uint32_t vtermno, int index) -{ - if (index < 0 || index >= MAX_NR_HVC_CONSOLES) - return -1; - - if (vtermnos[index] != -1) - return -1; - - vtermnos[index] = vtermno; - return 0; -} - -void hvc_console_print(struct console *co, const char *b, unsigned count) -{ - char c[16] __ALIGNED__; - unsigned i = 0, n = 0; - int r, donecr = 0; - - /* Console access attempt outside of acceptable console range. */ - if (co->index >= MAX_NR_HVC_CONSOLES) - return; - - /* This console adapter was removed so it is not useable. */ - if (vtermnos[co->index] < 0) - return; - - while (count > 0 || i > 0) { - if (count > 0 && i < sizeof(c)) { - if (b[n] == '\n' && !donecr) { - c[i++] = '\r'; - donecr = 1; - } else { - c[i++] = b[n++]; - donecr = 0; - --count; - } - } else { - r = hvc_put_chars(vtermnos[co->index], c, i); - if (r < 0) { - /* throw away chars on error */ - i = 0; - } else if (r > 0) { - i -= r; - if (i > 0) - memmove(c, c+r, i); - } - } - } -} - -static struct tty_driver *hvc_console_device(struct console *c, int *index) -{ - *index = c->index; - return hvc_driver; -} - -static int __init hvc_console_setup(struct console *co, char *options) -{ - return 0; -} - -struct console hvc_con_driver = { - .name = "hvc", - .write = hvc_console_print, - .device = hvc_console_device, - .setup = hvc_console_setup, - .flags = CON_PRINTBUFFER, - .index = -1, -}; - -/* Early console initialization. Preceeds driver initialization. */ -static int __init hvc_console_init(void) -{ - int i; - - for (i=0; i