diff options
Diffstat (limited to 'drivers/char/hvcs.c')
| -rw-r--r-- | drivers/char/hvcs.c | 1604 |
1 files changed, 0 insertions, 1604 deletions
diff --git a/drivers/char/hvcs.c b/drivers/char/hvcs.c deleted file mode 100644 index bedc6c1b6fa5..000000000000 --- a/drivers/char/hvcs.c +++ /dev/null @@ -1,1604 +0,0 @@ -/* - * IBM eServer Hypervisor Virtual Console Server Device Driver - * Copyright (C) 2003, 2004 IBM Corp. - * Ryan S. Arnold (rsa@us.ibm.com) - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - * - * Author(s) : Ryan S. Arnold <rsa@us.ibm.com> - * - * This is the device driver for the IBM Hypervisor Virtual Console Server, - * "hvcs". The IBM hvcs provides a tty driver interface to allow Linux - * user space applications access to the system consoles of logically - * partitioned operating systems, e.g. Linux, running on the same partitioned - * Power5 ppc64 system. Physical hardware consoles per partition are not - * practical on this hardware so system consoles are accessed by this driver - * using inter-partition firmware interfaces to virtual terminal devices. - * - * A vty is known to the HMC as a "virtual serial server adapter". It is a - * virtual terminal device that is created by firmware upon partition creation - * to act as a partitioned OS's console device. - * - * Firmware dynamically (via hotplug) exposes vty-servers to a running ppc64 - * Linux system upon their creation by the HMC or their exposure during boot. - * The non-user interactive backend of this driver is implemented as a vio - * device driver so that it can receive notification of vty-server lifetimes - * after it registers with the vio bus to handle vty-server probe and remove - * callbacks. - * - * Many vty-servers can be configured to connect to one vty, but a vty can - * only be actively connected to by a single vty-server, in any manner, at one - * time. If the HMC is currently hosting the console for a target Linux - * partition; attempts to open the tty device to the partition's console using - * the hvcs on any partition will return -EBUSY with every open attempt until - * the HMC frees the connection between its vty-server and the desired - * partition's vty device. Conversely, a vty-server may only be connected to - * a single vty at one time even though it may have several configured vty - * partner possibilities. - * - * Firmware does not provide notification of vty partner changes to this - * driver. This means that an HMC Super Admin may add or remove partner vtys - * from a vty-server's partner list but the changes will not be signaled to - * the vty-server. Firmware only notifies the driver when a vty-server is - * added or removed from the system. To compensate for this deficiency, this - * driver implements a sysfs update attribute which provides a method for - * rescanning partner information upon a user's request. - * - * Each vty-server, prior to being exposed to this driver is reference counted - * using the 2.6 Linux kernel kref construct. - * - * For direction on installation and usage of this driver please reference - * Documentation/powerpc/hvcs.txt. - */ - -#include <linux/device.h> -#include <linux/init.h> -#include <linux/interrupt.h> -#include <linux/kernel.h> -#include <linux/kref.h> -#include <linux/kthread.h> -#include <linux/list.h> -#include <linux/major.h> -#include <linux/module.h> -#include <linux/moduleparam.h> -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/spinlock.h> -#include <linux/stat.h> -#include <linux/tty.h> -#include <linux/tty_flip.h> -#include <asm/hvconsole.h> -#include <asm/hvcserver.h> -#include <asm/uaccess.h> -#include <asm/vio.h> - -/* - * 1.3.0 -> 1.3.1 In hvcs_open memset(..,0x00,..) instead of memset(..,0x3F,00). - * Removed braces around single statements following conditionals. Removed '= - * 0' after static int declarations since these default to zero. Removed - * list_for_each_safe() and replaced with list_for_each_entry() in - * hvcs_get_by_index(). The 'safe' version is un-needed now that the driver is - * using spinlocks. Changed spin_lock_irqsave() to spin_lock() when locking - * hvcs_structs_lock and hvcs_pi_lock since these are not touched in an int - * handler. Initialized hvcs_structs_lock and hvcs_pi_lock to - * SPIN_LOCK_UNLOCKED at declaration time rather than in hvcs_module_init(). - * Added spin_lock around list_del() in destroy_hvcs_struct() to protect the - * list traversals from a deletion. Removed '= NULL' from pointer declaration - * statements since they are initialized NULL by default. Removed wmb() - * instances from hvcs_try_write(). They probably aren't needed with locking in - * place. Added check and cleanup for hvcs_pi_buff = kmalloc() in - * hvcs_module_init(). Exposed hvcs_struct.index via a sysfs attribute so that - * the coupling between /dev/hvcs* and a vty-server can be automatically - * determined. Moved kobject_put() in hvcs_open outside of the - * spin_unlock_irqrestore(). - * - * 1.3.1 -> 1.3.2 Changed method for determining hvcs_struct->index and had it - * align with how the tty layer always assigns the lowest index available. This - * change resulted in a list of ints that denotes which indexes are available. - * Device additions and removals use the new hvcs_get_index() and - * hvcs_return_index() helper functions. The list is created with - * hvsc_alloc_index_list() and it is destroyed with hvcs_free_index_list(). - * Without these fixes hotplug vty-server adapter support goes crazy with this - * driver if the user removes a vty-server adapter. Moved free_irq() outside of - * the hvcs_final_close() function in order to get it out of the spinlock. - * Rearranged hvcs_close(). Cleaned up some printks and did some housekeeping - * on the changelog. Removed local CLC_LENGTH and used HVCS_CLC_LENGTH from - * arch/powerepc/include/asm/hvcserver.h - * - * 1.3.2 -> 1.3.3 Replaced yield() in hvcs_close() with tty_wait_until_sent() to - * prevent possible lockup with realtime scheduling as similarily pointed out by - * akpm in hvc_console. Changed resulted in the removal of hvcs_final_close() - * to reorder cleanup operations and prevent discarding of pending data during - * an hvcs_close(). Removed spinlock protection of hvcs_struct data members in - * hvcs_write_room() and hvcs_chars_in_buffer() because they aren't needed. - */ - -#define HVCS_DRIVER_VERSION "1.3.3" - -MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>"); -MODULE_DESCRIPTION("IBM hvcs (Hypervisor Virtual Console Server) Driver"); -MODULE_LICENSE("GPL"); -MODULE_VERSION(HVCS_DRIVER_VERSION); - -/* - * Wait this long per iteration while trying to push buffered data to the - * hypervisor before allowing the tty to complete a close operation. - */ -#define HVCS_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ - -/* - * Since the Linux TTY code does not currently (2-04-2004) support dynamic - * addition of tty derived devices and we shouldn't allocate thousands of - * tty_device pointers when the number of vty-server & vty partner connections - * will most often be much lower than this, we'll arbitrarily allocate - * HVCS_DEFAULT_SERVER_ADAPTERS tty_structs and cdev's by default when we - * register the tty_driver. This can be overridden using an insmod parameter. - */ -#define HVCS_DEFAULT_SERVER_ADAPTERS 64 - -/* - * The user can't insmod with more than HVCS_MAX_SERVER_ADAPTERS hvcs device - * nodes as a sanity check. Theoretically there can be over 1 Billion - * vty-server & vty partner connections. - */ -#define HVCS_MAX_SERVER_ADAPTERS 1024 - -/* - * We let Linux assign us a major number and we start the minors at zero. There - * is no intuitive mapping between minor number and the target vty-server - * adapter except that each new vty-server adapter is always assigned to the - * smallest minor number available. - */ -#define HVCS_MINOR_START 0 - -/* - * The hcall interface involves putting 8 chars into each of two registers. - * We load up those 2 registers (in arch/powerpc/platforms/pseries/hvconsole.c) - * by casting char[16] to long[2]. It would work without __ALIGNED__, but a - * little (tiny) bit slower because an unaligned load is slower than aligned - * load. - */ -#define __ALIGNED__ __attribute__((__aligned__(8))) - -/* - * How much data can firmware send with each hvc_put_chars()? Maybe this - * should be moved into an architecture specific area. - */ -#define HVCS_BUFF_LEN 16 - -/* - * This is the maximum amount of data we'll let the user send us (hvcs_write) at - * once in a chunk as a sanity check. - */ -#define HVCS_MAX_FROM_USER 4096 - -/* - * Be careful when adding flags to this line discipline. Don't add anything - * that will cause echoing or we'll go into recursive loop echoing chars back - * and forth with the console drivers. - */ -static struct ktermios hvcs_tty_termios = { - .c_iflag = IGNBRK | IGNPAR, - .c_oflag = OPOST, - .c_cflag = B38400 | CS8 | CREAD | HUPCL, - .c_cc = INIT_C_CC, - .c_ispeed = 38400, - .c_ospeed = 38400 -}; - -/* - * This value is used to take the place of a command line parameter when the - * module is inserted. It starts as -1 and stays as such if the user doesn't - * specify a module insmod parameter. If they DO specify one then it is set to - * the value of the integer passed in. - */ -static int hvcs_parm_num_devs = -1; -module_param(hvcs_parm_num_devs, int, 0); - -static const char hvcs_driver_name[] = "hvcs"; -static const char hvcs_device_node[] = "hvcs"; -static const char hvcs_driver_string[] - = "IBM hvcs (Hypervisor Virtual Console Server) Driver"; - -/* Status of partner info rescan triggered via sysfs. */ -static int hvcs_rescan_status; - -static struct tty_driver *hvcs_tty_driver; - -/* - * In order to be somewhat sane this driver always associates the hvcs_struct - * index element with the numerically equal tty->index. This means that a - * hotplugged vty-server adapter will always map to the lowest index valued - * device node. If vty-servers were hotplug removed from the system and then - * new ones added the new vty-server may have the largest slot number of all - * the vty-server adapters in the partition but it may have the lowest dev node - * index of all the adapters due to the hole left by the hotplug removed - * adapter. There are a set of functions provided to get the lowest index for - * a new device as well as return the index to the list. This list is allocated - * with a number of elements equal to the number of device nodes requested when - * the module was inserted. - */ -static int *hvcs_index_list; - -/* - * How large is the list? This is kept for traversal since the list is - * dynamically created. - */ -static int hvcs_index_count; - -/* - * Used by the khvcsd to pick up I/O operations when the kernel_thread is - * already awake but potentially shifted to TASK_INTERRUPTIBLE state. - */ -static int hvcs_kicked; - -/* - * Use by the kthread construct for task operations like waking the sleeping - * thread and stopping the kthread. - */ -static struct task_struct *hvcs_task; - -/* - * We allocate this for the use of all of the hvcs_structs when they fetch - * partner info. - */ -static unsigned long *hvcs_pi_buff; - -/* Only allow one hvcs_struct to use the hvcs_pi_buff at a time. */ -static DEFINE_SPINLOCK(hvcs_pi_lock); - -/* One vty-server per hvcs_struct */ -struct hvcs_struct { - spinlock_t lock; - - /* - * This index identifies this hvcs device as the complement to a - * specific tty index. - */ - unsigned int index; - - struct tty_struct *tty; - int open_count; - - /* - * Used to tell the driver kernel_thread what operations need to take - * place upon this hvcs_struct instance. - */ - int todo_mask; - - /* - * This buffer is required so that when hvcs_write_room() reports that - * it can send HVCS_BUFF_LEN characters that it will buffer the full - * HVCS_BUFF_LEN characters if need be. This is essential for opost - * writes since they do not do high level buffering and expect to be - * able to send what the driver commits to sending buffering - * [e.g. tab to space conversions in n_tty.c opost()]. - */ - char buffer[HVCS_BUFF_LEN]; - int chars_in_buffer; - - /* - * Any variable below the kref is valid before a tty is connected and - * stays valid after the tty is disconnected. These shouldn't be - * whacked until the koject refcount reaches zero though some entries - * may be changed via sysfs initiatives. - */ - struct kref kref; /* ref count & hvcs_struct lifetime */ - int connected; /* is the vty-server currently connected to a vty? */ - uint32_t p_unit_address; /* partner unit address */ - uint32_t p_partition_ID; /* partner partition ID */ - char p_location_code[HVCS_CLC_LENGTH + 1]; /* CLC + Null Term */ - struct list_head next; /* list management */ - struct vio_dev *vdev; -}; - -/* Required to back map a kref to its containing object */ -#define from_kref(k) container_of(k, struct hvcs_struct, kref) - -static LIST_HEAD(hvcs_structs); -static DEFINE_SPINLOCK(hvcs_structs_lock); - -static void hvcs_unthrottle(struct tty_struct *tty); -static void hvcs_throttle(struct tty_struct *tty); -static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance); - -static int hvcs_write(struct tty_struct *tty, - const unsigned char *buf, int count); -static int hvcs_write_room(struct tty_struct *tty); -static int hvcs_chars_in_buffer(struct tty_struct *tty); - -static int hvcs_has_pi(struct hvcs_struct *hvcsd); -static void hvcs_set_pi(struct hvcs_partner_info *pi, - struct hvcs_struct *hvcsd); -static int hvcs_get_pi(struct hvcs_struct *hvcsd); -static int hvcs_rescan_devices_list(void); - -static int hvcs_partner_connect(struct hvcs_struct *hvcsd); -static void hvcs_partner_free(struct hvcs_struct *hvcsd); - -static int hvcs_enable_device(struct hvcs_struct *hvcsd, - uint32_t unit_address, unsigned int irq, struct vio_dev *dev); - -static int hvcs_open(struct tty_struct *tty, struct file *filp); -static void hvcs_close(struct tty_struct *tty, struct file *filp); -static void hvcs_hangup(struct tty_struct * tty); - -static int __devinit hvcs_probe(struct vio_dev *dev, - const struct vio_device_id *id); -static int __devexit hvcs_remove(struct vio_dev *dev); -static int __init hvcs_module_init(void); -static void __exit hvcs_module_exit(void); - -#define HVCS_SCHED_READ 0x00000001 -#define HVCS_QUICK_READ 0x00000002 -#define HVCS_TRY_WRITE 0x00000004 -#define HVCS_READ_MASK (HVCS_SCHED_READ | HVCS_QUICK_READ) - -static inline struct hvcs_struct *from_vio_dev(struct vio_dev *viod) -{ - return dev_get_drvdata(&viod->dev); -} -/* The sysfs interface for the driver and devices */ - -static ssize_t hvcs_partner_vtys_show(struct device *dev, struct device_attribute *attr, char *buf) -{ - struct vio_dev *viod = to_vio_dev(dev); - struct hvcs_struct *hvcsd = from_vio_dev(viod); - unsigned long flags; - int retval; - - spin_lock_irqsave(&hvcsd->lock, flags); - retval = sprintf(buf, "%X\n", hvcsd->p_unit_address); - spin_unlock_irqrestore(&hvcsd->lock, flags); - return retval; -} -static DEVICE_ATTR(partner_vtys, S_IRUGO, hvcs_partner_vtys_show, NULL); - -static ssize_t hvcs_partner_clcs_show(struct device *dev, struct device_attribute *attr, char *buf) -{ - struct vio_dev *viod = to_vio_dev(dev); - struct hvcs_struct *hvcsd = from_vio_dev(viod); - unsigned long flags; - int retval; - - spin_lock_irqsave(&hvcsd->lock, flags); - retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]); - spin_unlock_irqrestore(&hvcsd->lock, flags); - return retval; -} -static DEVICE_ATTR(partner_clcs, S_IRUGO, hvcs_partner_clcs_show, NULL); - -static ssize_t hvcs_current_vty_store(struct device *dev, struct device_attribute *attr, const char * buf, - size_t count) -{ - /* - * Don't need this feature at the present time because firmware doesn't - * yet support multiple partners. - */ - printk(KERN_INFO "HVCS: Denied current_vty change: -EPERM.\n"); - return -EPERM; -} - -static ssize_t hvcs_current_vty_show(struct device *dev, struct device_attribute *attr, char *buf) -{ - struct vio_dev *viod = to_vio_dev(dev); - struct hvcs_struct *hvcsd = from_vio_dev(viod); - unsigned long flags; - int retval; - - spin_lock_irqsave(&hvcsd->lock, flags); - retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]); - spin_unlock_irqrestore(&hvcsd->lock, flags); - return retval; -} - -static DEVICE_ATTR(current_vty, - S_IRUGO | S_IWUSR, hvcs_current_vty_show, hvcs_current_vty_store); - -static ssize_t hvcs_vterm_state_store(struct device *dev, struct device_attribute *attr, const char *buf, - size_t count) -{ - struct vio_dev *viod = to_vio_dev(dev); - struct hvcs_struct *hvcsd = from_vio_dev(viod); - unsigned long flags; - - /* writing a '0' to this sysfs entry will result in the disconnect. */ - if (simple_strtol(buf, NULL, 0) != 0) - return -EINVAL; - - spin_lock_irqsave(&hvcsd->lock, flags); - - if (hvcsd->open_count > 0) { - spin_unlock_irqrestore(&hvcsd->lock, flags); - printk(KERN_INFO "HVCS: vterm state unchanged. " - "The hvcs device node is still in use.\n"); - return -EPERM; - } - - if (hvcsd->connected == 0) { - spin_unlock_irqrestore(&hvcsd->lock, flags); - printk(KERN_INFO "HVCS: vterm state unchanged. The" - " vty-server is not connected to a vty.\n"); - return -EPERM; - } - - hvcs_partner_free(hvcsd); - printk(KERN_INFO "HVCS: Closed vty-server@%X and" - " partner vty@%X:%d connection.\n", - hvcsd->vdev->unit_address, - hvcsd->p_unit_address, - (uint32_t)hvcsd->p_partition_ID); - - spin_unlock_irqrestore(&hvcsd->lock, flags); - return count; -} - -static ssize_t hvcs_vterm_state_show(struct device *dev, struct device_attribute *attr, char *buf) -{ - struct vio_dev *viod = to_vio_dev(dev); - struct hvcs_struct *hvcsd = from_vio_dev(viod); - unsigned long flags; - int retval; - - spin_lock_irqsave(&hvcsd->lock, flags); - retval = sprintf(buf, "%d\n", hvcsd->connected); - spin_unlock_irqrestore(&hvcsd->lock, flags); - return retval; -} -static DEVICE_ATTR(vterm_state, S_IRUGO | S_IWUSR, - hvcs_vterm_state_show, hvcs_vterm_state_store); - -static ssize_t hvcs_index_show(struct device *dev, struct device_attribute *attr, char *buf) -{ - struct vio_dev *viod = to_vio_dev(dev); - struct hvcs_struct *hvcsd = from_vio_dev(viod); - unsigned long flags; - int retval; - - spin_lock_irqsave(&hvcsd->lock, flags); - retval = sprintf(buf, "%d\n", hvcsd->index); - spin_unlock_irqrestore(&hvcsd->lock, flags); - return retval; -} - -static DEVICE_ATTR(index, S_IRUGO, hvcs_index_show, NULL); - -static struct attribute *hvcs_attrs[] = { - &dev_attr_partner_vtys.attr, - &dev_attr_partner_clcs.attr, - &dev_attr_current_vty.attr, - &dev_attr_vterm_state.attr, - &dev_attr_index.attr, - NULL, -}; - -static struct attribute_group hvcs_attr_group = { - .attrs = hvcs_attrs, -}; - -static ssize_t hvcs_rescan_show(struct device_driver *ddp, char *buf) -{ - /* A 1 means it is updating, a 0 means it is done updating */ - return snprintf(buf, PAGE_SIZE, "%d\n", hvcs_rescan_status); -} - -static ssize_t hvcs_rescan_store(struct device_driver *ddp, const char * buf, - size_t count) -{ - if ((simple_strtol(buf, NULL, 0) != 1) - && (hvcs_rescan_status != 0)) - return -EINVAL; - - hvcs_rescan_status = 1; - printk(KERN_INFO "HVCS: rescanning partner info for all" - " vty-servers.\n"); - hvcs_rescan_devices_list(); - hvcs_rescan_status = 0; - return count; -} - -static DRIVER_ATTR(rescan, - S_IRUGO | S_IWUSR, hvcs_rescan_show, hvcs_rescan_store); - -static void hvcs_kick(void) -{ - hvcs_kicked = 1; - wmb(); - wake_up_process(hvcs_task); -} - -static void hvcs_unthrottle(struct tty_struct *tty) -{ - struct hvcs_struct *hvcsd = tty->driver_data; - unsigned long flags; - - spin_lock_irqsave(&hvcsd->lock, flags); - hvcsd->todo_mask |= HVCS_SCHED_READ; - spin_unlock_irqrestore(&hvcsd->lock, flags); - hvcs_kick(); -} - -static void hvcs_throttle(struct tty_struct *tty) -{ - struct hvcs_struct *hvcsd = tty->driver_data; - unsigned long flags; - - spin_lock_irqsave(&hvcsd->lock, flags); - vio_disable_interrupts(hvcsd->vdev); - spin_unlock_irqrestore(&hvcsd->lock, flags); -} - -/* - * If the device is being removed we don't have to worry about this interrupt - * handler taking any further interrupts because they are disabled which means - * the hvcs_struct will always be valid in this handler. - */ -static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance) -{ - struct hvcs_struct *hvcsd = dev_instance; - - spin_lock(&hvcsd->lock); - vio_disable_interrupts(hvcsd->vdev); - hvcsd->todo_mask |= HVCS_SCHED_READ; - spin_unlock(&hvcsd->lock); - hvcs_kick(); - - return IRQ_HANDLED; -} - -/* This function must be called with the hvcsd->lock held */ -static void hvcs_try_write(struct hvcs_struct *hvcsd) -{ - uint32_t unit_address = hvcsd->vdev->unit_address; - struct tty_struct *tty = hvcsd->tty; - int sent; - - if (hvcsd->todo_mask & HVCS_TRY_WRITE) { - /* won't send partial writes */ - sent = hvc_put_chars(unit_address, - &hvcsd->buffer[0], - hvcsd->chars_in_buffer ); - if (sent > 0) { - hvcsd->chars_in_buffer = 0; - /* wmb(); */ - hvcsd->todo_mask &= ~(HVCS_TRY_WRITE); - /* wmb(); */ - - /* - * We are still obligated to deliver the data to the - * hypervisor even if the tty has been closed because - * we commited to delivering it. But don't try to wake - * a non-existent tty. - */ - if (tty) { - tty_wakeup(tty); - } - } - } -} - -static int hvcs_io(struct hvcs_struct *hvcsd) -{ - uint32_t unit_address; - struct tty_struct *tty; - char buf[HVCS_BUFF_LEN] __ALIGNED__; - unsigned long flags; - int got = 0; - - spin_lock_irqsave(&hvcsd->lock, flags); - - unit_address = hvcsd->vdev->unit_address; - tty = hvcsd->tty; - - hvcs_try_write(hvcsd); - - if (!tty || test_bit(TTY_THROTTLED, &tty->flags)) { - hvcsd->todo_mask &= ~(HVCS_READ_MASK); - goto bail; - } else if (!(hvcsd->todo_mask & (HVCS_READ_MASK))) - goto bail; - - /* remove the read masks */ - hvcsd->todo_mask &= ~(HVCS_READ_MASK); - - if (tty_buffer_request_room(tty, HVCS_BUFF_LEN) >= HVCS_BUFF_LEN) { - got = hvc_get_chars(unit_address, - &buf[0], - HVCS_BUFF_LEN); - tty_insert_flip_string(tty, buf, got); - } - - /* Give the TTY time to process the data we just sent. */ - if (got) - hvcsd->todo_mask |= HVCS_QUICK_READ; - - spin_unlock_irqrestore(&hvcsd->lock, flags); - /* This is synch because tty->low_latency == 1 */ - if(got) - tty_flip_buffer_push(tty); - - if (!got) { - /* Do this _after_ the flip_buffer_push */ - spin_lock_irqsave(&hvcsd->lock, flags); - vio_enable_interrupts(hvcsd->vdev); - spin_unlock_irqrestore(&hvcsd->lock, flags); - } - - return hvcsd->todo_mask; - - bail: - spin_unlock_irqrestore(&hvcsd->lock, flags); - return hvcsd->todo_mask; -} - -static int khvcsd(void *unused) -{ - struct hvcs_struct *hvcsd; - int hvcs_todo_mask; - - __set_current_state(TASK_RUNNING); - - do { - hvcs_todo_mask = 0; - hvcs_kicked = 0; - wmb(); - - spin_lock(&hvcs_structs_lock); - list_for_each_entry(hvcsd, &hvcs_structs, next) { - hvcs_todo_mask |= hvcs_io(hvcsd); - } - spin_unlock(&hvcs_structs_lock); - - /* - * If any of the hvcs adapters want to try a write or quick read - * don't schedule(), yield a smidgen then execute the hvcs_io - * thread again for those that want the write. - */ - if (hvcs_todo_mask & (HVCS_TRY_WRITE | HVCS_QUICK_READ)) { - yield(); - continue; - } - - set_current_state(TASK_INTERRUPTIBLE); - if (!hvcs_kicked) - schedule(); - __set_current_state(TASK_RUNNING); - } while (!kthread_should_stop()); - - return 0; -} - -static struct vio_device_id hvcs_driver_table[] __devinitdata= { - {"serial-server", "hvterm2"}, - { "", "" } -}; -MODULE_DEVICE_TABLE(vio, hvcs_driver_table); - -static void hvcs_return_index(int index) -{ - /* Paranoia check */ - if (!hvcs_index_list) - return; - if (index < 0 || index >= hvcs_index_count) - return; - if (hvcs_index_list[index] == -1) - return; - else - hvcs_index_list[index] = -1; -} - -/* callback when the kref ref count reaches zero */ -static void destroy_hvcs_struct(struct kref *kref) -{ - struct hvcs_struct *hvcsd = from_kref(kref); - struct vio_dev *vdev; - unsigned long flags; - - spin_lock(&hvcs_structs_lock); - spin_lock_irqsave(&hvcsd->lock, flags); - - /* the list_del poisons the pointers */ - list_del(&(hvcsd->next)); - - if (hvcsd->connected == 1) { - hvcs_partner_free(hvcsd); - printk(KERN_INFO "HVCS: Closed vty-server@%X and" - " partner vty@%X:%d connection.\n", - hvcsd->vdev->unit_address, - hvcsd->p_unit_address, - (uint32_t)hvcsd->p_partition_ID); - } - printk(KERN_INFO "HVCS: Destroyed hvcs_struct for vty-server@%X.\n", - hvcsd->vdev->unit_address); - - vdev = hvcsd->vdev; - hvcsd->vdev = NULL; - - hvcsd->p_unit_address = 0; - hvcsd->p_partition_ID = 0; - hvcs_return_index(hvcsd->index); - memset(&hvcsd->p_location_code[0], 0x00, HVCS_CLC_LENGTH + 1); - - spin_unlock_irqrestore(&hvcsd->lock, flags); - spin_unlock(&hvcs_structs_lock); - - sysfs_remove_group(&vdev->dev.kobj, &hvcs_attr_group); - - kfree(hvcsd); -} - -static int hvcs_get_index(void) -{ - int i; - /* Paranoia check */ - if (!hvcs_index_list) { - printk(KERN_ERR "HVCS: hvcs_index_list NOT valid!.\n"); - return -EFAULT; - } - /* Find the numerically lowest first free index. */ - for(i = 0; i < hvcs_index_count; i++) { - if (hvcs_index_list[i] == -1) { - hvcs_index_list[i] = 0; - return i; - } - } - return -1; -} - -static int __devinit hvcs_probe( - struct vio_dev *dev, - const struct vio_device_id *id) -{ - struct hvcs_struct *hvcsd; - int index; - int retval; - - if (!dev || !id) { - printk(KERN_ERR "HVCS: probed with invalid parameter.\n"); - return -EPERM; - } - - /* early to avoid cleanup on failure */ - index = hvcs_get_index(); - if (index < 0) { - return -EFAULT; - } - - hvcsd = kzalloc(sizeof(*hvcsd), GFP_KERNEL); - if (!hvcsd) - return -ENODEV; - - - spin_lock_init(&hvcsd->lock); - /* Automatically incs the refcount the first time */ - kref_init(&hvcsd->kref); - - hvcsd->vdev = dev; - dev_set_drvdata(&dev->dev, hvcsd); - - hvcsd->index = index; - - /* hvcsd->index = ++hvcs_struct_count; */ - hvcsd->chars_in_buffer = 0; - hvcsd->todo_mask = 0; - hvcsd->connected = 0; - - /* - * This will populate the hvcs_struct's partner info fields for the - * first time. - */ - if (hvcs_get_pi(hvcsd)) { - printk(KERN_ERR "HVCS: Failed to fetch partner" - " info for vty-server@%X on device probe.\n", - hvcsd->vdev->unit_address); - } - - /* - * If a user app opens a tty that corresponds to this vty-server before - * the hvcs_struct has been added to the devices list then the user app - * will get -ENODEV. - */ - spin_lock(&hvcs_structs_lock); - list_add_tail(&(hvcsd->next), &hvcs_structs); - spin_unlock(&hvcs_structs_lock); - - retval = sysfs_create_group(&dev->dev.kobj, &hvcs_attr_group); - if (retval) { - printk(KERN_ERR "HVCS: Can't create sysfs attrs for vty-server@%X\n", - hvcsd->vdev->unit_address); - return retval; - } - - printk(KERN_INFO "HVCS: vty-server@%X added to the vio bus.\n", dev->unit_address); - - /* - * DON'T enable interrupts here because there is no user to receive the - * data. - */ - return 0; -} - -static int __devexit hvcs_remove(struct vio_dev *dev) -{ - struct hvcs_struct *hvcsd = dev_get_drvdata(&dev->dev); - unsigned long flags; - struct tty_struct *tty; - - if (!hvcsd) - return -ENODEV; - - /* By this time the vty-server won't be getting any more interrupts */ - - spin_lock_irqsave(&hvcsd->lock, flags); - - tty = hvcsd->tty; - - spin_unlock_irqrestore(&hvcsd->lock, flags); - - /* - * Let the last holder of this object cause it to be removed, which - * would probably be tty_hangup below. - */ - kref_put(&hvcsd->kref, destroy_hvcs_struct); - - /* - * The hangup is a scheduled function which will auto chain call - * hvcs_hangup. The tty should always be valid at this time unless a - * simultaneous tty close already cleaned up the hvcs_struct. - */ - if (tty) - tty_hangup(tty); - - printk(KERN_INFO "HVCS: vty-server@%X removed from the" - " vio bus.\n", dev->unit_address); - return 0; -}; - -static struct vio_driver hvcs_vio_driver = { - .id_table = hvcs_driver_table, - .probe = hvcs_probe, - .remove = __devexit_p(hvcs_remove), - .driver = { - .name = hvcs_driver_name, - .owner = THIS_MODULE, - } -}; - -/* Only called from hvcs_get_pi please */ -static void hvcs_set_pi(struct hvcs_partner_info *pi, struct hvcs_struct *hvcsd) -{ - int clclength; - - hvcsd->p_unit_address = pi->unit_address; - hvcsd->p_partition_ID = pi->partition_ID; - clclength = strlen(&pi->location_code[0]); - if (clclength > HVCS_CLC_LENGTH) - clclength = HVCS_CLC_LENGTH; - - /* copy the null-term char too */ - strncpy(&hvcsd->p_location_code[0], - &pi->location_code[0], clclength + 1); -} - -/* - * Traverse the list and add the partner info that is found to the hvcs_struct - * struct entry. NOTE: At this time I know that partner info will return a - * single entry but in the future there may be multiple partner info entries per - * vty-server and you'll want to zero out that list and reset it. If for some - * reason you have an old version of this driver but there IS more than one - * partner info then hvcsd->p_* will hold the last partner info data from the - * firmware query. A good way to update this code would be to replace the three - * partner info fields in hvcs_struct with a list of hvcs_partner_info - * instances. - * - * This function must be called with the hvcsd->lock held. - */ -static int hvcs_get_pi(struct hvcs_struct *hvcsd) -{ - struct hvcs_partner_info *pi; - uint32_t unit_address = hvcsd->vdev->unit_address; - struct list_head head; - int retval; - - spin_lock(&hvcs_pi_lock); - if (!hvcs_pi_buff) { - spin_unlock(&hvcs_pi_lock); - return -EFAULT; - } - retval = hvcs_get_partner_info(unit_address, &head, hvcs_pi_buff); - spin_unlock(&hvcs_pi_lock); - if (retval) { - printk(KERN_ERR "HVCS: Failed to fetch partner" - " info for vty-server@%x.\n", unit_address); - return retval; - } - - /* nixes the values if the partner vty went away */ - hvcsd->p_unit_address = 0; - hvcsd->p_partition_ID = 0; - - list_for_each_entry(pi, &head, node) - hvcs_set_pi(pi, hvcsd); - - hvcs_free_partner_info(&head); - return 0; -} - -/* - * This function is executed by the driver "rescan" sysfs entry. It shouldn't - * be executed elsewhere, in order to prevent deadlock issues. - */ -static int hvcs_rescan_devices_list(void) -{ - struct hvcs_struct *hvcsd; - unsigned long flags; - - spin_lock(&hvcs_structs_lock); - - list_for_each_entry(hvcsd, &hvcs_structs, next) { - spin_lock_irqsave(&hvcsd->lock, flags); - hvcs_get_pi(hvcsd); - spin_unlock_irqrestore(&hvcsd->lock, flags); - } - - spin_unlock(&hvcs_structs_lock); - - return 0; -} - -/* - * Farm this off into its own function because it could be more complex once - * multiple partners support is added. This function should be called with - * the hvcsd->lock held. - */ -static int hvcs_has_pi(struct hvcs_struct *hvcsd) -{ - if ((!hvcsd->p_unit_address) || (!hvcsd->p_partition_ID)) - return 0; - return 1; -} - -/* - * NOTE: It is possible that the super admin removed a partner vty and then - * added a different vty as the new partner. - * - * This function must be called with the hvcsd->lock held. - */ -static int hvcs_partner_connect(struct hvcs_struct *hvcsd) -{ - int retval; - unsigned int unit_address = hvcsd->vdev->unit_address; - - /* - * If there wasn't any pi when the device was added it doesn't meant - * there isn't any now. This driver isn't notified when a new partner - * vty is added to a vty-server so we discover changes on our own. - * Please see comments in hvcs_register_connection() for justification - * of this bizarre code. - */ - retval = hvcs_register_connection(unit_address, - hvcsd->p_partition_ID, - hvcsd->p_unit_address); - if (!retval) { - hvcsd->connected = 1; - return 0; - } else if (retval != -EINVAL) - return retval; - - /* - * As per the spec re-get the pi and try again if -EINVAL after the - * first connection attempt. - */ - if (hvcs_get_pi(hvcsd)) - return -ENOMEM; - - if (!hvcs_has_pi(hvcsd)) - return -ENODEV; - - retval = hvcs_register_connection(unit_address, - hvcsd->p_partition_ID, - hvcsd->p_unit_address); - if (retval != -EINVAL) { - hvcsd->connected = 1; - return retval; - } - - /* - * EBUSY is the most likely scenario though the vty could have been - * removed or there really could be an hcall error due to the parameter - * data but thanks to ambiguous firmware return codes we can't really - * tell. - */ - printk(KERN_INFO "HVCS: vty-server or partner" - " vty is busy. Try again later.\n"); - return -EBUSY; -} - -/* This function must be called with the hvcsd->lock held */ -static void hvcs_partner_free(struct hvcs_struct *hvcsd) -{ - int retval; - do { - retval = hvcs_free_connection(hvcsd->vdev->unit_address); - } while (retval == -EBUSY); - hvcsd->connected = 0; -} - -/* This helper function must be called WITHOUT the hvcsd->lock held */ -static int hvcs_enable_device(struct hvcs_struct *hvcsd, uint32_t unit_address, - unsigned int irq, struct vio_dev *vdev) -{ - unsigned long flags; - int rc; - - /* - * It is possible that the vty-server was removed between the time that - * the conn was registered and now. - */ - if (!(rc = request_irq(irq, &hvcs_handle_interrupt, - IRQF_DISABLED, "ibmhvcs", hvcsd))) { - /* - * It is possible the vty-server was removed after the irq was - * requested but before we have time to enable interrupts. - */ - if (vio_enable_interrupts(vdev) == H_SUCCESS) - return 0; - else { - printk(KERN_ERR "HVCS: int enable failed for" - " vty-server@%X.\n", unit_address); - free_irq(irq, hvcsd); - } - } else - printk(KERN_ERR "HVCS: irq req failed for" - " vty-server@%X.\n", unit_address); - - spin_lock_irqsave(&hvcsd->lock, flags); - hvcs_partner_free(hvcsd); - spin_unlock_irqrestore(&hvcsd->lock, flags); - - return rc; - -} - -/* - * This always increments the kref ref count if the call is successful. - * Please remember to dec when you are done with the instance. - * - * NOTICE: Do NOT hold either the hvcs_struct.lock or hvcs_structs_lock when - * calling this function or you will get deadlock. - */ -static struct hvcs_struct *hvcs_get_by_index(int index) -{ - struct hvcs_struct *hvcsd = NULL; - unsigned long flags; - - spin_lock(&hvcs_structs_lock); - /* We can immediately discard OOB requests */ - if (index >= 0 && index < HVCS_MAX_SERVER_ADAPTERS) { - list_for_each_entry(hvcsd, &hvcs_structs, next) { - spin_lock_irqsave(&hvcsd->lock, flags); - if (hvcsd->index == index) { - kref_get(&hvcsd->kref); - spin_unlock_irqrestore(&hvcsd->lock, flags); - spin_unlock(&hvcs_structs_lock); - return hvcsd; - } - spin_unlock_irqrestore(&hvcsd->lock, flags); - } - hvcsd = NULL; - } - - spin_unlock(&hvcs_structs_lock); - return hvcsd; -} - -/* - * This is invoked via the tty_open interface when a user app connects to the - * /dev node. - */ -static int hvcs_open(struct tty_struct *tty, struct file *filp) -{ - struct hvcs_struct *hvcsd; - int rc, retval = 0; - unsigned long flags; - unsigned int irq; - struct vio_dev *vdev; - unsigned long unit_address; - - if (tty->driver_data) - goto fast_open; - - /* - * Is there a vty-server that shares the same index? - * This function increments the kref index. - */ - if (!(hvcsd = hvcs_get_by_index(tty->index))) { - printk(KERN_WARNING "HVCS: open failed, no device associated" - " with tty->index %d.\n", tty->index); - return -ENODEV; - } - - spin_lock_irqsave(&hvcsd->lock, flags); - - if (hvcsd->connected == 0) - if ((retval = hvcs_partner_connect(hvcsd))) - goto error_release; - - hvcsd->open_count = 1; - hvcsd->tty = tty; - tty->driver_data = hvcsd; - - memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN); - - /* - * Save these in the spinlock for the enable operations that need them - * outside of the spinlock. - */ - irq = hvcsd->vdev->irq; - vdev = hvcsd->vdev; - unit_address = hvcsd->vdev->unit_address; - - hvcsd->todo_mask |= HVCS_SCHED_READ; - spin_unlock_irqrestore(&hvcsd->lock, flags); - - /* - * This must be done outside of the spinlock because it requests irqs - * and will grab the spinlock and free the connection if it fails. - */ - if (((rc = hvcs_enable_device(hvcsd, unit_address, irq, vdev)))) { - kref_put(&hvcsd->kref, destroy_hvcs_struct); - printk(KERN_WARNING "HVCS: enable device failed.\n"); - return rc; - } - - goto open_success; - -fast_open: - hvcsd = tty->driver_data; - - spin_lock_irqsave(&hvcsd->lock, flags); - kref_get(&hvcsd->kref); - hvcsd->open_count++; - hvcsd->todo_mask |= HVCS_SCHED_READ; - spin_unlock_irqrestore(&hvcsd->lock, flags); - -open_success: - hvcs_kick(); - - printk(KERN_INFO "HVCS: vty-server@%X connection opened.\n", - hvcsd->vdev->unit_address ); - - return 0; - -error_release: - spin_unlock_irqrestore(&hvcsd->lock, flags); - kref_put(&hvcsd->kref, destroy_hvcs_struct); - - printk(KERN_WARNING "HVCS: partner connect failed.\n"); - return retval; -} - -static void hvcs_close(struct tty_struct *tty, struct file *filp) -{ - struct hvcs_struct *hvcsd; - unsigned long flags; - int irq = NO_IRQ; - - /* - * Is someone trying to close the file associated with this device after - * we have hung up? If so tty->driver_data wouldn't be valid. - */ - if (tty_hung_up_p(filp)) - return; - - /* - * No driver_data means that this close was probably issued after a - * failed hvcs_open by the tty layer's release_dev() api and we can just - * exit cleanly. - */ - if (!tty->driver_data) - return; - - hvcsd = tty->driver_data; - - spin_lock_irqsave(&hvcsd->lock, flags); - if (--hvcsd->open_count == 0) { - - vio_disable_interrupts(hvcsd->vdev); - - /* - * NULL this early so that the kernel_thread doesn't try to - * execute any operations on the TTY even though it is obligated - * to deliver any pending I/O to the hypervisor. - */ - hvcsd->tty = NULL; - - irq = hvcsd->vdev->irq; - spin_unlock_irqrestore(&hvcsd->lock, flags); - - tty_wait_until_sent(tty, HVCS_CLOSE_WAIT); - - /* - * This line is important because it tells hvcs_open that this - * device needs to be re-configured the next time hvcs_open is - * called. - */ - tty->driver_data = NULL; - - free_irq(irq, hvcsd); - kref_put(&hvcsd->kref, destroy_hvcs_struct); - return; - } else if (hvcsd->open_count < 0) { - printk(KERN_ERR "HVCS: vty-server@%X open_count: %d" - " is missmanaged.\n", - hvcsd->vdev->unit_address, hvcsd->open_count); - } - - spin_unlock_irqrestore(&hvcsd->lock, flags); - kref_put(&hvcsd->kref, destroy_hvcs_struct); -} - -static void hvcs_hangup(struct tty_struct * tty) -{ - struct hvcs_struct *hvcsd = tty->driver_data; - unsigned long flags; - int temp_open_count; - int irq = NO_IRQ; - - spin_lock_irqsave(&hvcsd->lock, flags); - /* Preserve this so that we know how many kref refs to put */ - temp_open_count = hvcsd->open_count; - - /* - * Don't kref put inside the spinlock because the destruction - * callback may use the spinlock and it may get called before the - * spinlock has been released. - */ - vio_disable_interrupts(hvcsd->vdev); - - hvcsd->todo_mask = 0; - - /* I don't think the tty needs the hvcs_struct pointer after a hangup */ - hvcsd->tty->driver_data = NULL; - hvcsd->tty = NULL; - - hvcsd->open_count = 0; - - /* This will drop any buffered data on the floor which is OK in a hangup - * scenario. */ - memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN); - hvcsd->chars_in_buffer = 0; - - irq = hvcsd->vdev->irq; - - spin_unlock_irqrestore(&hvcsd->lock, flags); - - free_irq(irq, hvcsd); - - /* - * We need to kref_put() for every open_count we have since the - * tty_hangup() function doesn't invoke a close per open connection on a - * non-console device. - */ - while(temp_open_count) { - --temp_open_count; - /* - * The final put will trigger destruction of the hvcs_struct. - * NOTE: If this hangup was signaled from user space then the - * final put will never happen. - */ - kref_put(&hvcsd->kref, destroy_hvcs_struct); - } -} - -/* - * NOTE: This is almost always from_user since user level apps interact with the - * /dev nodes. I'm trusting that if hvcs_write gets called and interrupted by - * hvcs_remove (which removes the target device and executes tty_hangup()) that - * tty_hangup will allow hvcs_write time to complete execution before it - * terminates our device. - */ -static int hvcs_write(struct tty_struct *tty, - const unsigned char *buf, int count) -{ - struct hvcs_struct *hvcsd = tty->driver_data; - unsigned int unit_address; - const unsigned char *charbuf; - unsigned long flags; - int total_sent = 0; - int tosend = 0; - int result = 0; - - /* - * If they don't check the return code off of their open they may - * attempt this even if there is no connected device. - */ - if (!hvcsd) - return -ENODEV; - - /* Reasonable size to prevent user level flooding */ - if (count > HVCS_MAX_FROM_USER) { - printk(KERN_WARNING "HVCS write: count being truncated to" - " HVCS_MAX_FROM_USER.\n"); - count = HVCS_MAX_FROM_USER; - } - - charbuf = buf; - - spin_lock_irqsave(&hvcsd->lock, flags); - - /* - * Somehow an open succedded but the device was removed or the - * connection terminated between the vty-server and partner vty during - * the middle of a write operation? This is a crummy place to do this - * but we want to keep it all in the spinlock. - */ - if (hvcsd->open_count <= 0) { - spin_unlock_irqrestore(&hvcsd->lock, flags); - return -ENODEV; - } - - unit_address = hvcsd->vdev->unit_address; - - while (count > 0) { - tosend = min(count, (HVCS_BUFF_LEN - hvcsd->chars_in_buffer)); - /* - * No more space, this probably means that the last call to - * hvcs_write() didn't succeed and the buffer was filled up. - */ - if (!tosend) - break; - - memcpy(&hvcsd->buffer[hvcsd->chars_in_buffer], - &charbuf[total_sent], - tosend); - - hvcsd->chars_in_buffer += tosend; - - result = 0; - - /* - * If this is true then we don't want to try writing to the - * hypervisor because that is the kernel_threads job now. We'll - * just add to the buffer. - */ - if (!(hvcsd->todo_mask & HVCS_TRY_WRITE)) - /* won't send partial writes */ - result = hvc_put_chars(unit_address, - &hvcsd->buffer[0], - hvcsd->chars_in_buffer); - - /* - * Since we know we have enough room in hvcsd->buffer for - * tosend we record that it was sent regardless of whether the - * hypervisor actually took it because we have it buffered. - */ - total_sent+=tosend; - count-=tosend; - if (result == 0) { - hvcsd->todo_mask |= HVCS_TRY_WRITE; - hvcs_kick(); - break; - } - - hvcsd->chars_in_buffer = 0; - /* - * Test after the chars_in_buffer reset otherwise this could - * deadlock our writes if hvc_put_chars fails. - */ - if (result < 0) - break; - } - - spin_unlock_irqrestore(&hvcsd->lock, flags); - - if (result == -1) - return -EIO; - else - return total_sent; -} - -/* - * This is really asking how much can we guarentee that we can send or that we - * absolutely WILL BUFFER if we can't send it. This driver MUST honor the - * return value, hence the reason for hvcs_struct buffering. - */ -static int hvcs_write_room(struct tty_struct *tty) -{ - struct hvcs_struct *hvcsd = tty->driver_data; - - if (!hvcsd || hvcsd->open_count <= 0) - return 0; - - return HVCS_BUFF_LEN - hvcsd->chars_in_buffer; -} - -static int hvcs_chars_in_buffer(struct tty_struct *tty) -{ - struct hvcs_struct *hvcsd = tty->driver_data; - - return hvcsd->chars_in_buffer; -} - -static const struct tty_operations hvcs_ops = { - .open = hvcs_open, - .close = hvcs_close, - .hangup = hvcs_hangup, - .write = hvcs_write, - .write_room = hvcs_write_room, - .chars_in_buffer = hvcs_chars_in_buffer, - .unthrottle = hvcs_unthrottle, - .throttle = hvcs_throttle, -}; - -static int hvcs_alloc_index_list(int n) -{ - int i; - - hvcs_index_list = kmalloc(n * sizeof(hvcs_index_count),GFP_KERNEL); - if (!hvcs_index_list) - return -ENOMEM; - hvcs_index_count = n; - for (i = 0; i < hvcs_index_count; i++) - hvcs_index_list[i] = -1; - return 0; -} - -static void hvcs_free_index_list(void) -{ - /* Paranoia check to be thorough. */ - kfree(hvcs_index_list); - hvcs_index_list = NULL; - hvcs_index_count = 0; -} - -static int __init hvcs_module_init(void) -{ - int rc; - int num_ttys_to_alloc; - - printk(KERN_INFO "Initializing %s\n", hvcs_driver_string); - - /* Has the user specified an overload with an insmod param? */ - if (hvcs_parm_num_devs <= 0 || - (hvcs_parm_num_devs > HVCS_MAX_SERVER_ADAPTERS)) { - num_ttys_to_alloc = HVCS_DEFAULT_SERVER_ADAPTERS; - } else - num_ttys_to_alloc = hvcs_parm_num_devs; - - hvcs_tty_driver = alloc_tty_driver(num_ttys_to_alloc); - if (!hvcs_tty_driver) - return -ENOMEM; - - if (hvcs_alloc_index_list(num_ttys_to_alloc)) { - rc = -ENOMEM; - goto index_fail; - } - - hvcs_tty_driver->owner = THIS_MODULE; - - hvcs_tty_driver->driver_name = hvcs_driver_name; - hvcs_tty_driver->name = hvcs_device_node; - - /* - * We'll let the system assign us a major number, indicated by leaving - * it blank. - */ - - hvcs_tty_driver->minor_start = HVCS_MINOR_START; - hvcs_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; - - /* - * We role our own so that we DONT ECHO. We can't echo because the - * device we are connecting to already echoes by default and this would - * throw us into a horrible recursive echo-echo-echo loop. - */ - hvcs_tty_driver->init_termios = hvcs_tty_termios; - hvcs_tty_driver->flags = TTY_DRIVER_REAL_RAW; - - tty_set_operations(hvcs_tty_driver, &hvcs_ops); - - /* - * The following call will result in sysfs entries that denote the - * dynamically assigned major and minor numbers for our devices. - */ - if (tty_register_driver(hvcs_tty_driver)) { - printk(KERN_ERR "HVCS: registration as a tty driver failed.\n"); - rc = -EIO; - goto register_fail; - } - - hvcs_pi_buff = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!hvcs_pi_buff) { - rc = -ENOMEM; - goto buff_alloc_fail; - } - - hvcs_task = kthread_run(khvcsd, NULL, "khvcsd"); - if (IS_ERR(hvcs_task)) { - printk(KERN_ERR "HVCS: khvcsd creation failed. Driver not loaded.\n"); - rc = -EIO; - goto kthread_fail; - } - - rc = vio_register_driver(&hvcs_vio_driver); - if (rc) { - printk(KERN_ERR "HVCS: can't register vio driver\n"); - goto vio_fail; - } - - /* - * This needs to be done AFTER the vio_register_driver() call or else - * the kobjects won't be initialized properly. - */ - rc = driver_create_file(&(hvcs_vio_driver.driver), &driver_attr_rescan); - if (rc) { - printk(KERN_ERR "HVCS: sysfs attr create failed\n"); - goto attr_fail; - } - - printk(KERN_INFO "HVCS: driver module inserted.\n"); - - return 0; - -attr_fail: - vio_unregister_driver(&hvcs_vio_driver); -vio_fail: - kthread_stop(hvcs_task); -kthread_fail: - kfree(hvcs_pi_buff); -buff_alloc_fail: - tty_unregister_driver(hvcs_tty_driver); -register_fail: - hvcs_free_index_list(); -index_fail: - put_tty_driver(hvcs_tty_driver); - hvcs_tty_driver = NULL; - return rc; -} - -static void __exit hvcs_module_exit(void) -{ - /* - * This driver receives hvcs_remove callbacks for each device upon - * module removal. - */ - - /* - * This synchronous operation will wake the khvcsd kthread if it is - * asleep and will return when khvcsd has terminated. - */ - kthread_stop(hvcs_task); - - spin_lock(&hvcs_pi_lock); - kfree(hvcs_pi_buff); - hvcs_pi_buff = NULL; - spin_unlock(&hvcs_pi_lock); - - driver_remove_file(&hvcs_vio_driver.driver, &driver_attr_rescan); - - vio_unregister_driver(&hvcs_vio_driver); - - tty_unregister_driver(hvcs_tty_driver); - - hvcs_free_index_list(); - - put_tty_driver(hvcs_tty_driver); - - printk(KERN_INFO "HVCS: driver module removed.\n"); -} - -module_init(hvcs_module_init); -module_exit(hvcs_module_exit); |