+++ /dev/null
-/*
- * 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);
projects / mv-sheeva.git / blobdiff