diff options
| -rw-r--r-- | arch/sparc/include/asm/vio.h | 9 | ||||
| -rw-r--r-- | arch/sparc/kernel/vio.c | 1 | ||||
| -rw-r--r-- | arch/sparc/kernel/viohs.c | 12 | ||||
| -rw-r--r-- | drivers/tty/vcc.c | 379 |
4 files changed, 398 insertions, 3 deletions
diff --git a/arch/sparc/include/asm/vio.h b/arch/sparc/include/asm/vio.h index d1c47e9f0090..f3d4ac232690 100644 --- a/arch/sparc/include/asm/vio.h +++ b/arch/sparc/include/asm/vio.h @@ -52,6 +52,7 @@ struct vio_ver_info { #define VDEV_NETWORK_SWITCH 0x02 #define VDEV_DISK 0x03 #define VDEV_DISK_SERVER 0x04 +#define VDEV_CONSOLE_CON 0x05 u8 resv1[3]; u64 resv2[5]; @@ -282,6 +283,14 @@ struct vio_dring_state { struct ldc_trans_cookie cookies[VIO_MAX_RING_COOKIES]; }; +#define VIO_TAG_SIZE ((int)sizeof(struct vio_msg_tag)) +#define VIO_VCC_MTU_SIZE (LDC_PACKET_SIZE - VIO_TAG_SIZE) + +struct vio_vcc { + struct vio_msg_tag tag; + char data[VIO_VCC_MTU_SIZE]; +}; + static inline void *vio_dring_cur(struct vio_dring_state *dr) { return dr->base + (dr->entry_size * dr->prod); diff --git a/arch/sparc/kernel/vio.c b/arch/sparc/kernel/vio.c index 1c8763c9c52b..da1ac3f22b24 100644 --- a/arch/sparc/kernel/vio.c +++ b/arch/sparc/kernel/vio.c @@ -246,6 +246,7 @@ u64 vio_vdev_node(struct mdesc_handle *hp, struct vio_dev *vdev) return node; } +EXPORT_SYMBOL(vio_vdev_node); static void vio_fill_channel_info(struct mdesc_handle *hp, u64 mp, struct vio_dev *vdev) diff --git a/arch/sparc/kernel/viohs.c b/arch/sparc/kernel/viohs.c index d4f13c037a40..dcd278f29573 100644 --- a/arch/sparc/kernel/viohs.c +++ b/arch/sparc/kernel/viohs.c @@ -814,15 +814,21 @@ int vio_driver_init(struct vio_driver_state *vio, struct vio_dev *vdev, case VDEV_NETWORK_SWITCH: case VDEV_DISK: case VDEV_DISK_SERVER: + case VDEV_CONSOLE_CON: break; default: return -EINVAL; } - if (!ops || !ops->send_attr || !ops->handle_attr || - !ops->handshake_complete) - return -EINVAL; + if (dev_class == VDEV_NETWORK || + dev_class == VDEV_NETWORK_SWITCH || + dev_class == VDEV_DISK || + dev_class == VDEV_DISK_SERVER) { + if (!ops || !ops->send_attr || !ops->handle_attr || + !ops->handshake_complete) + return -EINVAL; + } if (!ver_table || ver_table_size < 0) return -EINVAL; diff --git a/drivers/tty/vcc.c b/drivers/tty/vcc.c index ba3384d23d79..4edace1d9e4b 100644 --- a/drivers/tty/vcc.c +++ b/drivers/tty/vcc.c @@ -3,8 +3,13 @@ * Copyright (C) 2017 Oracle. All rights reserved. */ +#include <linux/delay.h> +#include <linux/interrupt.h> #include <linux/module.h> +#include <linux/slab.h> #include <linux/tty.h> +#include <asm/vio.h> +#include <asm/ldc.h> #define DRV_MODULE_NAME "vcc" #define DRV_MODULE_VERSION "1.1" @@ -17,6 +22,33 @@ MODULE_DESCRIPTION("Sun LDOM virtual console concentrator driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_MODULE_VERSION); +struct vcc_port { + struct vio_driver_state vio; + + spinlock_t lock; + char *domain; + struct tty_struct *tty; /* only populated while dev is open */ + unsigned long index; /* index into the vcc_table */ + + u64 refcnt; + bool excl_locked; + + bool removed; + + /* This buffer is required to support the tty write_room interface + * and guarantee that any characters that the driver accepts will + * be eventually sent, either immediately or later. + */ + int chars_in_buffer; + struct vio_vcc buffer; + + struct timer_list rx_timer; + struct timer_list tx_timer; +}; + +/* Microseconds that thread will delay waiting for a vcc port ref */ +#define VCC_REF_DELAY 100 + #define VCC_MAX_PORTS 1024 #define VCC_MINOR_START 0 /* must be zero */ @@ -24,6 +56,9 @@ static const char vcc_driver_name[] = "vcc"; static const char vcc_device_node[] = "vcc"; static struct tty_driver *vcc_tty_driver; +static struct vcc_port *vcc_table[VCC_MAX_PORTS]; +static DEFINE_SPINLOCK(vcc_table_lock); + int vcc_dbg; int vcc_dbg_ldc; int vcc_dbg_vio; @@ -70,6 +105,340 @@ static struct ktermios vcc_tty_termios = { .c_ospeed = 38400 }; +/** + * vcc_table_add() - Add VCC port to the VCC table + * @port: pointer to the VCC port + * + * Return: index of the port in the VCC table on success, + * -1 on failure + */ +static int vcc_table_add(struct vcc_port *port) +{ + unsigned long flags; + int i; + + spin_lock_irqsave(&vcc_table_lock, flags); + for (i = VCC_MINOR_START; i < VCC_MAX_PORTS; i++) { + if (!vcc_table[i]) { + vcc_table[i] = port; + break; + } + } + spin_unlock_irqrestore(&vcc_table_lock, flags); + + if (i < VCC_MAX_PORTS) + return i; + else + return -1; +} + +/** + * vcc_table_remove() - Removes a VCC port from the VCC table + * @index: Index into the VCC table + */ +static void vcc_table_remove(unsigned long index) +{ + unsigned long flags; + + if (WARN_ON(index >= VCC_MAX_PORTS)) + return; + + spin_lock_irqsave(&vcc_table_lock, flags); + vcc_table[index] = NULL; + spin_unlock_irqrestore(&vcc_table_lock, flags); +} + +/** + * vcc_get() - Gets a reference to VCC port + * @index: Index into the VCC table + * @excl: Indicates if an exclusive access is requested + * + * Return: reference to the VCC port, if found + * NULL, if port not found + */ +static struct vcc_port *vcc_get(unsigned long index, bool excl) +{ + struct vcc_port *port; + unsigned long flags; + +try_again: + spin_lock_irqsave(&vcc_table_lock, flags); + + port = vcc_table[index]; + if (!port) { + spin_unlock_irqrestore(&vcc_table_lock, flags); + return NULL; + } + + if (!excl) { + if (port->excl_locked) { + spin_unlock_irqrestore(&vcc_table_lock, flags); + udelay(VCC_REF_DELAY); + goto try_again; + } + port->refcnt++; + spin_unlock_irqrestore(&vcc_table_lock, flags); + return port; + } + + if (port->refcnt) { + spin_unlock_irqrestore(&vcc_table_lock, flags); + /* Threads wanting exclusive access will wait half the time, + * probably giving them higher priority in the case of + * multiple waiters. + */ + udelay(VCC_REF_DELAY/2); + goto try_again; + } + + port->refcnt++; + port->excl_locked = true; + spin_unlock_irqrestore(&vcc_table_lock, flags); + + return port; +} + +/** + * vcc_put() - Returns a reference to VCC port + * @port: pointer to VCC port + * @excl: Indicates if the returned reference is an exclusive reference + * + * Note: It's the caller's responsibility to ensure the correct value + * for the excl flag + */ +static void vcc_put(struct vcc_port *port, bool excl) +{ + unsigned long flags; + + if (!port) + return; + + spin_lock_irqsave(&vcc_table_lock, flags); + + /* check if caller attempted to put with the wrong flags */ + if (WARN_ON((excl && !port->excl_locked) || + (!excl && port->excl_locked))) + goto done; + + port->refcnt--; + + if (excl) + port->excl_locked = false; + +done: + spin_unlock_irqrestore(&vcc_table_lock, flags); +} + +/** + * vcc_get_ne() - Get a non-exclusive reference to VCC port + * @index: Index into the VCC table + * + * Gets a non-exclusive reference to VCC port, if it's not removed + * + * Return: pointer to the VCC port, if found + * NULL, if port not found + */ +static struct vcc_port *vcc_get_ne(unsigned long index) +{ + struct vcc_port *port; + + port = vcc_get(index, false); + + if (port && port->removed) { + vcc_put(port, false); + return NULL; + } + + return port; +} + +static void vcc_event(void *arg, int event) +{ +} + +static struct ldc_channel_config vcc_ldc_cfg = { + .event = vcc_event, + .mtu = VIO_VCC_MTU_SIZE, + .mode = LDC_MODE_RAW, + .debug = 0, +}; + +/* Ordered from largest major to lowest */ +static struct vio_version vcc_versions[] = { + { .major = 1, .minor = 0 }, +}; + +/** + * vcc_probe() - Initialize VCC port + * @vdev: Pointer to VIO device of the new VCC port + * @id: VIO device ID + * + * Initializes a VCC port to receive serial console data from + * the guest domain. Sets up a TTY end point on the control + * domain. Sets up VIO/LDC link between the guest & control + * domain endpoints. + * + * Return: status of the probe + */ +static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id) +{ + struct mdesc_handle *hp; + struct vcc_port *port; + struct device *dev; + const char *domain; + char *name; + u64 node; + int rv; + + vccdbg("VCC: name=%s\n", dev_name(&vdev->dev)); + + if (!vcc_tty_driver) { + pr_err("VCC: TTY driver not registered\n"); + return -ENODEV; + } + + port = kzalloc(sizeof(struct vcc_port), GFP_KERNEL); + if (!port) + return -ENOMEM; + + name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL); + + rv = vio_driver_init(&port->vio, vdev, VDEV_CONSOLE_CON, vcc_versions, + ARRAY_SIZE(vcc_versions), NULL, name); + if (rv) + goto free_port; + + port->vio.debug = vcc_dbg_vio; + vcc_ldc_cfg.debug = vcc_dbg_ldc; + + rv = vio_ldc_alloc(&port->vio, &vcc_ldc_cfg, port); + if (rv) + goto free_port; + + spin_lock_init(&port->lock); + + port->index = vcc_table_add(port); + if (port->index == -1) { + pr_err("VCC: no more TTY indices left for allocation\n"); + goto free_ldc; + } + + /* Register the device using VCC table index as TTY index */ + dev = tty_register_device(vcc_tty_driver, port->index, &vdev->dev); + if (IS_ERR(dev)) { + rv = PTR_ERR(dev); + goto free_table; + } + + hp = mdesc_grab(); + + node = vio_vdev_node(hp, vdev); + if (node == MDESC_NODE_NULL) { + rv = -ENXIO; + mdesc_release(hp); + goto unreg_tty; + } + + domain = mdesc_get_property(hp, node, "vcc-domain-name", NULL); + if (!domain) { + rv = -ENXIO; + mdesc_release(hp); + goto unreg_tty; + } + port->domain = kstrdup(domain, GFP_KERNEL); + + mdesc_release(hp); + + dev_set_drvdata(&vdev->dev, port); + + /* It's possible to receive IRQs in the middle of vio_port_up. Disable + * IRQs until the port is up. + */ + disable_irq_nosync(vdev->rx_irq); + vio_port_up(&port->vio); + enable_irq(vdev->rx_irq); + + return 0; + +unreg_tty: + tty_unregister_device(vcc_tty_driver, port->index); +free_table: + vcc_table_remove(port->index); +free_ldc: + vio_ldc_free(&port->vio); +free_port: + kfree(name); + kfree(port); + + return rv; +} + +/** + * vcc_remove() - Terminate a VCC port + * @vdev: Pointer to VIO device of the VCC port + * + * Terminates a VCC port. Sets up the teardown of TTY and + * VIO/LDC link between guest and primary domains. + * + * Return: status of removal + */ +static int vcc_remove(struct vio_dev *vdev) +{ + struct vcc_port *port = dev_get_drvdata(&vdev->dev); + + if (!port) + return -ENODEV; + + /* If there's a process with the device open, do a synchronous + * hangup of the TTY. This *may* cause the process to call close + * asynchronously, but it's not guaranteed. + */ + if (port->tty) + tty_vhangup(port->tty); + + /* Get exclusive reference to VCC, ensures that there are no other + * clients to this port + */ + port = vcc_get(port->index, true); + + if (WARN_ON(!port)) + return -ENODEV; + + tty_unregister_device(vcc_tty_driver, port->index); + + del_timer_sync(&port->vio.timer); + vio_ldc_free(&port->vio); + dev_set_drvdata(&vdev->dev, NULL); + + if (port->tty) { + port->removed = true; + vcc_put(port, true); + } else { + vcc_table_remove(port->index); + + kfree(port->vio.name); + kfree(port->domain); + kfree(port); + } + + return 0; +} + +static const struct vio_device_id vcc_match[] = { + { + .type = "vcc-port", + }, + {}, +}; +MODULE_DEVICE_TABLE(vio, vcc_match); + +static struct vio_driver vcc_driver = { + .id_table = vcc_match, + .probe = vcc_probe, + .remove = vcc_remove, + .name = "vcc", +}; + static const struct tty_operations vcc_ops; #define VCC_TTY_FLAGS (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW) @@ -127,11 +496,21 @@ static int __init vcc_init(void) return rv; } + rv = vio_register_driver(&vcc_driver); + if (rv) { + pr_err("VCC: VIO driver registration failed\n"); + vcc_tty_exit(); + } else { + vccdbg("VCC: VIO driver registered successfully\n"); + } + return rv; } static void __exit vcc_exit(void) { + vio_unregister_driver(&vcc_driver); + vccdbg("VCC: VIO driver unregistered\n"); vcc_tty_exit(); vccdbg("VCC: TTY driver unregistered\n"); } |