| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Ryan S. Arnold | 2628 | 52.46% | 4 | 6.15% |
| Linas Vepstas | 1769 | 35.31% | 1 | 1.54% |
| Jiri Slaby | 205 | 4.09% | 14 | 21.54% |
| Brian King | 140 | 2.79% | 6 | 9.23% |
| Benjamin Herrenschmidt | 114 | 2.28% | 2 | 3.08% |
| Yani Ioannou | 35 | 0.70% | 1 | 1.54% |
| Greg Kroah-Hartman | 29 | 0.58% | 5 | 7.69% |
| Alan Cox | 18 | 0.36% | 2 | 3.08% |
| Anton Blanchard | 11 | 0.22% | 2 | 3.08% |
| Thomas Gleixner | 8 | 0.16% | 1 | 1.54% |
| Tyrel Datwyler | 7 | 0.14% | 1 | 1.54% |
| Chen Gang S | 6 | 0.12% | 1 | 1.54% |
| Stephen Rothwell | 5 | 0.10% | 1 | 1.54% |
| Lucas De Marchi | 4 | 0.08% | 1 | 1.54% |
| Linus Torvalds | 3 | 0.06% | 3 | 4.62% |
| Andrew Morton | 3 | 0.06% | 1 | 1.54% |
| Al Viro | 3 | 0.06% | 1 | 1.54% |
| Kees Cook | 2 | 0.04% | 1 | 1.54% |
| Wei Yongjun | 2 | 0.04% | 1 | 1.54% |
| Cheng Renquan | 2 | 0.04% | 1 | 1.54% |
| Linus Torvalds (pre-git) | 2 | 0.04% | 1 | 1.54% |
| Peter Hurley | 2 | 0.04% | 2 | 3.08% |
| Colin Ian King | 1 | 0.02% | 1 | 1.54% |
| Yong Zhang | 1 | 0.02% | 1 | 1.54% |
| Uwe Kleine-König | 1 | 0.02% | 1 | 1.54% |
| Mauro Carvalho Chehab | 1 | 0.02% | 1 | 1.54% |
| Bhumika Goyal | 1 | 0.02% | 1 | 1.54% |
| Joe Perches | 1 | 0.02% | 1 | 1.54% |
| Wan Jiabing | 1 | 0.02% | 1 | 1.54% |
| Jon Mason | 1 | 0.02% | 1 | 1.54% |
| Yoann Padioleau | 1 | 0.02% | 1 | 1.54% |
| Wolfram Sang | 1 | 0.02% | 1 | 1.54% |
| Arvind Yadav | 1 | 0.02% | 1 | 1.54% |
| Segher Boessenkool | 1 | 0.02% | 1 | 1.54% |
| Total | 5010 | 65 |
// SPDX-License-Identifier: GPL-2.0+ /* * IBM eServer Hypervisor Virtual Console Server Device Driver * Copyright (C) 2003, 2004 IBM Corp. * Ryan S. Arnold (rsa@us.ibm.com) * * 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.rst. */ #include <linux/device.h> #include <linux/init.h> #include <linux/completion.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 <linux/uaccess.h> #include <linux/termios_internal.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 similarly 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 const 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"; /* 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 { struct tty_port port; spinlock_t lock; /* * This index identifies this hvcs device as the complement to a * specific tty index. */ unsigned int index; /* * 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 is valid before a tty is connected and * stays valid after the tty is disconnected. These shouldn't be * whacked until the kobject refcount reaches zero though some entries * may be changed via sysfs initiatives. */ 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; struct completion *destroyed; }; static LIST_HEAD(hvcs_structs); static DEFINE_SPINLOCK(hvcs_structs_lock); static DEFINE_MUTEX(hvcs_init_mutex); static int hvcs_get_pi(struct hvcs_struct *hvcsd); static int hvcs_rescan_devices_list(void); static void hvcs_partner_free(struct hvcs_struct *hvcsd); static int hvcs_initialize(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->port.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_dev_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, }; ATTRIBUTE_GROUPS(hvcs_dev); static ssize_t 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 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_RW(rescan); static struct attribute *hvcs_attrs[] = { &driver_attr_rescan.attr, NULL, }; ATTRIBUTE_GROUPS(hvcs); 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->port.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 committed 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->port.tty; hvcs_try_write(hvcsd); if (!tty || tty_throttled(tty)) { 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(&hvcsd->port, HVCS_BUFF_LEN) >= HVCS_BUFF_LEN) { got = hvc_get_chars(unit_address, &buf[0], HVCS_BUFF_LEN); tty_insert_flip_string(&hvcsd->port, 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 -- FIXME :js: it is not! */ if (got) tty_flip_buffer_push(&hvcsd->port); else { /* 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 const struct vio_device_id hvcs_driver_table[] = { {"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; } static void hvcs_destruct_port(struct tty_port *p) { struct hvcs_struct *hvcsd = container_of(p, struct hvcs_struct, port); struct vio_dev *vdev; struct completion *comp; unsigned long flags; spin_lock(&hvcs_structs_lock); spin_lock_irqsave(&hvcsd->lock, flags); comp = hvcsd->destroyed; /* 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; hvcsd->destroyed = NULL; 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); kfree(hvcsd); if (comp) complete(comp); } static const struct tty_port_operations hvcs_port_ops = { .destruct = hvcs_destruct_port, }; 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 hvcs_probe( struct vio_dev *dev, const struct vio_device_id *id) { struct hvcs_struct *hvcsd; int index, rc; if (!dev || !id) { printk(KERN_ERR "HVCS: probed with invalid parameter.\n"); return -EPERM; } /* Make sure we are properly initialized */ rc = hvcs_initialize(); if (rc) { pr_err("HVCS: Failed to initialize core driver.\n"); return rc; } /* 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; tty_port_init(&hvcsd->port); hvcsd->port.ops = &hvcs_port_ops; spin_lock_init(&hvcsd->lock); 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); 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 void hvcs_remove(struct vio_dev *dev) { struct hvcs_struct *hvcsd = dev_get_drvdata(&dev->dev); DECLARE_COMPLETION_ONSTACK(comp); unsigned long flags; struct tty_struct *tty; /* By this time the vty-server won't be getting any more interrupts */ spin_lock_irqsave(&hvcsd->lock, flags); hvcsd->destroyed = ∁ tty = tty_port_tty_get(&hvcsd->port); spin_unlock_irqrestore(&hvcsd->lock, flags); /* * The tty should always be valid at this time unless a * simultaneous tty close already cleaned up the hvcs_struct. */ if (tty) { tty_vhangup(tty); tty_kref_put(tty); } tty_port_put(&hvcsd->port); wait_for_completion(&comp); printk(KERN_INFO "HVCS: vty-server@%X removed from the" " vio bus.\n", dev->unit_address); }; static struct vio_driver hvcs_vio_driver = { .id_table = hvcs_driver_table, .probe = hvcs_probe, .remove = hvcs_remove, .name = hvcs_driver_name, .driver = { .groups = hvcs_groups, .dev_groups = hvcs_dev_groups, }, }; /* Only called from hvcs_get_pi please */ static void hvcs_set_pi(struct hvcs_partner_info *pi, struct hvcs_struct *hvcsd) { hvcsd->p_unit_address = pi->unit_address; hvcsd->p_partition_ID = pi->partition_ID; /* copy the null-term char too */ strscpy(hvcsd->p_location_code, pi->location_code, sizeof(hvcsd->p_location_code)); } /* * 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. */ rc = request_irq(irq, &hvcs_handle_interrupt, 0, "ibmhvcs", hvcsd); if (!rc) { /* * 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; unsigned long flags; spin_lock(&hvcs_structs_lock); list_for_each_entry(hvcsd, &hvcs_structs, next) { spin_lock_irqsave(&hvcsd->lock, flags); if (hvcsd->index == index) { tty_port_get(&hvcsd->port); spin_unlock_irqrestore(&hvcsd->lock, flags); spin_unlock(&hvcs_structs_lock); return hvcsd; } spin_unlock_irqrestore(&hvcsd->lock, flags); } spin_unlock(&hvcs_structs_lock); return NULL; } static int hvcs_install(struct tty_driver *driver, struct tty_struct *tty) { struct hvcs_struct *hvcsd; struct vio_dev *vdev; unsigned long unit_address, flags; unsigned int irq; int retval; /* * Is there a vty-server that shares the same index? * This function increments the kref index. */ hvcsd = hvcs_get_by_index(tty->index); if (!hvcsd) { 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) { retval = hvcs_partner_connect(hvcsd); if (retval) { spin_unlock_irqrestore(&hvcsd->lock, flags); printk(KERN_WARNING "HVCS: partner connect failed.\n"); goto err_put; } } hvcsd->port.count = 0; hvcsd->port.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. */ retval = hvcs_enable_device(hvcsd, unit_address, irq, vdev); if (retval) { printk(KERN_WARNING "HVCS: enable device failed.\n"); goto err_put; } retval = tty_port_install(&hvcsd->port, driver, tty); if (retval) goto err_irq; return 0; err_irq: spin_lock_irqsave(&hvcsd->lock, flags); vio_disable_interrupts(hvcsd->vdev); spin_unlock_irqrestore(&hvcsd->lock, flags); free_irq(irq, hvcsd); err_put: tty_port_put(&hvcsd->port); return retval; } /* * 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 = tty->driver_data; unsigned long flags; spin_lock_irqsave(&hvcsd->lock, flags); hvcsd->port.count++; hvcsd->todo_mask |= HVCS_SCHED_READ; spin_unlock_irqrestore(&hvcsd->lock, flags); hvcs_kick(); printk(KERN_INFO "HVCS: vty-server@%X connection opened.\n", hvcsd->vdev->unit_address ); return 0; } static void hvcs_close(struct tty_struct *tty, struct file *filp) { struct hvcs_struct *hvcsd; unsigned long flags; int 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->port.count == 0) { spin_unlock_irqrestore(&hvcsd->lock, flags); return; } else if (--hvcsd->port.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->port.tty = NULL; irq = hvcsd->vdev->irq; spin_unlock_irqrestore(&hvcsd->lock, flags); tty_wait_until_sent(tty, HVCS_CLOSE_WAIT); free_irq(irq, hvcsd); return; } else if (hvcsd->port.count < 0) { printk(KERN_ERR "HVCS: vty-server@%X open_count: %d is mismanaged.\n", hvcsd->vdev->unit_address, hvcsd->port.count); } spin_unlock_irqrestore(&hvcsd->lock, flags); } static void hvcs_cleanup(struct tty_struct * tty) { struct hvcs_struct *hvcsd = tty->driver_data; /* * 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; tty_port_put(&hvcsd->port); } static void hvcs_hangup(struct tty_struct * tty) { struct hvcs_struct *hvcsd = tty->driver_data; unsigned long flags; int irq; spin_lock_irqsave(&hvcsd->lock, flags); /* * 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; hvcsd->port.tty = NULL; hvcsd->port.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); } /* * 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 succeeded 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->port.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 guarantee 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 unsigned int hvcs_write_room(struct tty_struct *tty) { struct hvcs_struct *hvcsd = tty->driver_data; if (!hvcsd || hvcsd->port.count <= 0) return 0; return HVCS_BUFF_LEN - hvcsd->chars_in_buffer; } static unsigned 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 = { .install = hvcs_install, .open = hvcs_open, .close = hvcs_close, .cleanup = hvcs_cleanup, .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_array(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 hvcs_initialize(void) { int rc, num_ttys_to_alloc; mutex_lock(&hvcs_init_mutex); if (hvcs_task) { mutex_unlock(&hvcs_init_mutex); return 0; } /* 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 = tty_alloc_driver(num_ttys_to_alloc, TTY_DRIVER_REAL_RAW); if (IS_ERR(hvcs_tty_driver)) { mutex_unlock(&hvcs_init_mutex); return PTR_ERR(hvcs_tty_driver); } if (hvcs_alloc_index_list(num_ttys_to_alloc)) { rc = -ENOMEM; goto index_fail; } 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; 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 = (unsigned long *) __get_free_page(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.\n"); rc = -EIO; goto kthread_fail; } mutex_unlock(&hvcs_init_mutex); return 0; kthread_fail: free_page((unsigned long)hvcs_pi_buff); buff_alloc_fail: tty_unregister_driver(hvcs_tty_driver); register_fail: hvcs_free_index_list(); index_fail: tty_driver_kref_put(hvcs_tty_driver); hvcs_tty_driver = NULL; mutex_unlock(&hvcs_init_mutex); return rc; } static int __init hvcs_module_init(void) { int rc = vio_register_driver(&hvcs_vio_driver); if (rc) { printk(KERN_ERR "HVCS: can't register vio driver\n"); return rc; } pr_info("HVCS: Driver registered.\n"); return 0; } static void __exit hvcs_module_exit(void) { /* * This driver receives hvcs_remove callbacks for each device upon * module removal. */ vio_unregister_driver(&hvcs_vio_driver); if (!hvcs_task) return; /* * 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); free_page((unsigned long)hvcs_pi_buff); hvcs_pi_buff = NULL; spin_unlock(&hvcs_pi_lock); tty_unregister_driver(hvcs_tty_driver); hvcs_free_index_list(); tty_driver_kref_put(hvcs_tty_driver); printk(KERN_INFO "HVCS: driver module removed.\n"); } module_init(hvcs_module_init); module_exit(hvcs_module_exit);
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