sparc64: vcc: Enable VCC port probe and removal
Enables VCC port probe and removal to initialize and terminate VCC ports respectively. When a device/port matching the VCC driver is added, the probe function is invoked along with a reference to the device. remove function is called when the device is removed. Also add APIs to cache and retrieve VCC ports from a VCC table Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jag Raman
David S. Miller
parent
ce808b7463
commit
5d171050e2
@ -52,6 +52,7 @@ struct vio_ver_info {
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#define VDEV_NETWORK_SWITCH 0x02
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#define VDEV_DISK 0x03
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#define VDEV_DISK_SERVER 0x04
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#define VDEV_CONSOLE_CON 0x05
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u8 resv1[3];
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u64 resv2[5];
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@ -282,6 +283,14 @@ struct vio_dring_state {
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struct ldc_trans_cookie cookies[VIO_MAX_RING_COOKIES];
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};
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#define VIO_TAG_SIZE ((int)sizeof(struct vio_msg_tag))
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#define VIO_VCC_MTU_SIZE (LDC_PACKET_SIZE - VIO_TAG_SIZE)
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struct vio_vcc {
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struct vio_msg_tag tag;
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char data[VIO_VCC_MTU_SIZE];
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};
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static inline void *vio_dring_cur(struct vio_dring_state *dr)
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{
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return dr->base + (dr->entry_size * dr->prod);
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@ -246,6 +246,7 @@ u64 vio_vdev_node(struct mdesc_handle *hp, struct vio_dev *vdev)
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return node;
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}
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EXPORT_SYMBOL(vio_vdev_node);
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static void vio_fill_channel_info(struct mdesc_handle *hp, u64 mp,
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struct vio_dev *vdev)
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@ -814,15 +814,21 @@ int vio_driver_init(struct vio_driver_state *vio, struct vio_dev *vdev,
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case VDEV_NETWORK_SWITCH:
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case VDEV_DISK:
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case VDEV_DISK_SERVER:
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case VDEV_CONSOLE_CON:
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break;
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default:
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return -EINVAL;
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}
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if (!ops || !ops->send_attr || !ops->handle_attr ||
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!ops->handshake_complete)
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return -EINVAL;
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if (dev_class == VDEV_NETWORK ||
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dev_class == VDEV_NETWORK_SWITCH ||
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dev_class == VDEV_DISK ||
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dev_class == VDEV_DISK_SERVER) {
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if (!ops || !ops->send_attr || !ops->handle_attr ||
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!ops->handshake_complete)
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return -EINVAL;
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}
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if (!ver_table || ver_table_size < 0)
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return -EINVAL;
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@ -3,8 +3,13 @@
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* Copyright (C) 2017 Oracle. All rights reserved.
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*/
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/tty.h>
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#include <asm/vio.h>
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#include <asm/ldc.h>
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#define DRV_MODULE_NAME "vcc"
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#define DRV_MODULE_VERSION "1.1"
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@ -17,6 +22,33 @@ MODULE_DESCRIPTION("Sun LDOM virtual console concentrator driver");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(DRV_MODULE_VERSION);
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struct vcc_port {
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struct vio_driver_state vio;
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spinlock_t lock;
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char *domain;
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struct tty_struct *tty; /* only populated while dev is open */
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unsigned long index; /* index into the vcc_table */
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u64 refcnt;
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bool excl_locked;
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bool removed;
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/* This buffer is required to support the tty write_room interface
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* and guarantee that any characters that the driver accepts will
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* be eventually sent, either immediately or later.
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*/
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int chars_in_buffer;
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struct vio_vcc buffer;
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struct timer_list rx_timer;
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struct timer_list tx_timer;
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};
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/* Microseconds that thread will delay waiting for a vcc port ref */
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#define VCC_REF_DELAY 100
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#define VCC_MAX_PORTS 1024
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#define VCC_MINOR_START 0 /* must be zero */
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@ -24,6 +56,9 @@ static const char vcc_driver_name[] = "vcc";
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static const char vcc_device_node[] = "vcc";
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static struct tty_driver *vcc_tty_driver;
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static struct vcc_port *vcc_table[VCC_MAX_PORTS];
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static DEFINE_SPINLOCK(vcc_table_lock);
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int vcc_dbg;
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int vcc_dbg_ldc;
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int vcc_dbg_vio;
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@ -70,6 +105,340 @@ static struct ktermios vcc_tty_termios = {
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.c_ospeed = 38400
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};
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/**
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* vcc_table_add() - Add VCC port to the VCC table
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* @port: pointer to the VCC port
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*
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* Return: index of the port in the VCC table on success,
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* -1 on failure
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*/
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static int vcc_table_add(struct vcc_port *port)
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{
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unsigned long flags;
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int i;
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spin_lock_irqsave(&vcc_table_lock, flags);
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for (i = VCC_MINOR_START; i < VCC_MAX_PORTS; i++) {
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if (!vcc_table[i]) {
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vcc_table[i] = port;
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break;
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}
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}
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spin_unlock_irqrestore(&vcc_table_lock, flags);
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if (i < VCC_MAX_PORTS)
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return i;
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else
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return -1;
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}
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/**
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* vcc_table_remove() - Removes a VCC port from the VCC table
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* @index: Index into the VCC table
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*/
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static void vcc_table_remove(unsigned long index)
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{
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unsigned long flags;
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if (WARN_ON(index >= VCC_MAX_PORTS))
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return;
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spin_lock_irqsave(&vcc_table_lock, flags);
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vcc_table[index] = NULL;
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spin_unlock_irqrestore(&vcc_table_lock, flags);
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}
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/**
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* vcc_get() - Gets a reference to VCC port
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* @index: Index into the VCC table
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* @excl: Indicates if an exclusive access is requested
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*
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* Return: reference to the VCC port, if found
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* NULL, if port not found
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*/
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static struct vcc_port *vcc_get(unsigned long index, bool excl)
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{
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struct vcc_port *port;
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unsigned long flags;
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try_again:
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spin_lock_irqsave(&vcc_table_lock, flags);
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port = vcc_table[index];
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if (!port) {
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spin_unlock_irqrestore(&vcc_table_lock, flags);
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return NULL;
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}
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if (!excl) {
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if (port->excl_locked) {
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spin_unlock_irqrestore(&vcc_table_lock, flags);
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udelay(VCC_REF_DELAY);
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goto try_again;
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}
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port->refcnt++;
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spin_unlock_irqrestore(&vcc_table_lock, flags);
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return port;
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}
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if (port->refcnt) {
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spin_unlock_irqrestore(&vcc_table_lock, flags);
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/* Threads wanting exclusive access will wait half the time,
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* probably giving them higher priority in the case of
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* multiple waiters.
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*/
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udelay(VCC_REF_DELAY/2);
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goto try_again;
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}
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port->refcnt++;
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port->excl_locked = true;
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spin_unlock_irqrestore(&vcc_table_lock, flags);
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return port;
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}
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/**
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* vcc_put() - Returns a reference to VCC port
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* @port: pointer to VCC port
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* @excl: Indicates if the returned reference is an exclusive reference
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*
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* Note: It's the caller's responsibility to ensure the correct value
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* for the excl flag
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*/
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static void vcc_put(struct vcc_port *port, bool excl)
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{
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unsigned long flags;
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if (!port)
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return;
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spin_lock_irqsave(&vcc_table_lock, flags);
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/* check if caller attempted to put with the wrong flags */
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if (WARN_ON((excl && !port->excl_locked) ||
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(!excl && port->excl_locked)))
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goto done;
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port->refcnt--;
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if (excl)
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port->excl_locked = false;
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done:
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spin_unlock_irqrestore(&vcc_table_lock, flags);
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}
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/**
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* vcc_get_ne() - Get a non-exclusive reference to VCC port
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* @index: Index into the VCC table
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*
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* Gets a non-exclusive reference to VCC port, if it's not removed
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*
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* Return: pointer to the VCC port, if found
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* NULL, if port not found
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*/
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static struct vcc_port *vcc_get_ne(unsigned long index)
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{
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struct vcc_port *port;
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port = vcc_get(index, false);
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if (port && port->removed) {
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vcc_put(port, false);
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return NULL;
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}
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return port;
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}
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static void vcc_event(void *arg, int event)
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{
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}
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static struct ldc_channel_config vcc_ldc_cfg = {
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.event = vcc_event,
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.mtu = VIO_VCC_MTU_SIZE,
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.mode = LDC_MODE_RAW,
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.debug = 0,
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};
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/* Ordered from largest major to lowest */
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static struct vio_version vcc_versions[] = {
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{ .major = 1, .minor = 0 },
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};
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/**
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* vcc_probe() - Initialize VCC port
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* @vdev: Pointer to VIO device of the new VCC port
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* @id: VIO device ID
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*
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* Initializes a VCC port to receive serial console data from
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* the guest domain. Sets up a TTY end point on the control
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* domain. Sets up VIO/LDC link between the guest & control
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* domain endpoints.
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*
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* Return: status of the probe
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*/
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static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
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{
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struct mdesc_handle *hp;
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struct vcc_port *port;
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struct device *dev;
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const char *domain;
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char *name;
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u64 node;
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int rv;
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vccdbg("VCC: name=%s\n", dev_name(&vdev->dev));
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if (!vcc_tty_driver) {
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pr_err("VCC: TTY driver not registered\n");
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return -ENODEV;
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}
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port = kzalloc(sizeof(struct vcc_port), GFP_KERNEL);
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if (!port)
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return -ENOMEM;
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name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL);
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rv = vio_driver_init(&port->vio, vdev, VDEV_CONSOLE_CON, vcc_versions,
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ARRAY_SIZE(vcc_versions), NULL, name);
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if (rv)
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goto free_port;
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port->vio.debug = vcc_dbg_vio;
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vcc_ldc_cfg.debug = vcc_dbg_ldc;
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rv = vio_ldc_alloc(&port->vio, &vcc_ldc_cfg, port);
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if (rv)
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goto free_port;
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spin_lock_init(&port->lock);
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port->index = vcc_table_add(port);
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if (port->index == -1) {
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pr_err("VCC: no more TTY indices left for allocation\n");
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goto free_ldc;
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}
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/* Register the device using VCC table index as TTY index */
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dev = tty_register_device(vcc_tty_driver, port->index, &vdev->dev);
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if (IS_ERR(dev)) {
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rv = PTR_ERR(dev);
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goto free_table;
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}
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hp = mdesc_grab();
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node = vio_vdev_node(hp, vdev);
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if (node == MDESC_NODE_NULL) {
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rv = -ENXIO;
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mdesc_release(hp);
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goto unreg_tty;
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}
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domain = mdesc_get_property(hp, node, "vcc-domain-name", NULL);
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if (!domain) {
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rv = -ENXIO;
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mdesc_release(hp);
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goto unreg_tty;
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}
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port->domain = kstrdup(domain, GFP_KERNEL);
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mdesc_release(hp);
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dev_set_drvdata(&vdev->dev, port);
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/* It's possible to receive IRQs in the middle of vio_port_up. Disable
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* IRQs until the port is up.
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*/
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disable_irq_nosync(vdev->rx_irq);
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vio_port_up(&port->vio);
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enable_irq(vdev->rx_irq);
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return 0;
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unreg_tty:
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tty_unregister_device(vcc_tty_driver, port->index);
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free_table:
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vcc_table_remove(port->index);
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free_ldc:
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vio_ldc_free(&port->vio);
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free_port:
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kfree(name);
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kfree(port);
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return rv;
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}
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/**
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* vcc_remove() - Terminate a VCC port
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* @vdev: Pointer to VIO device of the VCC port
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*
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* Terminates a VCC port. Sets up the teardown of TTY and
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* VIO/LDC link between guest and primary domains.
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*
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* Return: status of removal
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*/
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static int vcc_remove(struct vio_dev *vdev)
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{
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struct vcc_port *port = dev_get_drvdata(&vdev->dev);
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if (!port)
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return -ENODEV;
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/* If there's a process with the device open, do a synchronous
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* hangup of the TTY. This *may* cause the process to call close
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* asynchronously, but it's not guaranteed.
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*/
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if (port->tty)
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tty_vhangup(port->tty);
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/* Get exclusive reference to VCC, ensures that there are no other
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* clients to this port
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*/
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port = vcc_get(port->index, true);
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if (WARN_ON(!port))
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return -ENODEV;
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tty_unregister_device(vcc_tty_driver, port->index);
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del_timer_sync(&port->vio.timer);
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vio_ldc_free(&port->vio);
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dev_set_drvdata(&vdev->dev, NULL);
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if (port->tty) {
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port->removed = true;
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vcc_put(port, true);
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} else {
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vcc_table_remove(port->index);
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kfree(port->vio.name);
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kfree(port->domain);
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kfree(port);
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}
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return 0;
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}
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static const struct vio_device_id vcc_match[] = {
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{
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.type = "vcc-port",
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},
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{},
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};
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MODULE_DEVICE_TABLE(vio, vcc_match);
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static struct vio_driver vcc_driver = {
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.id_table = vcc_match,
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.probe = vcc_probe,
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.remove = vcc_remove,
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.name = "vcc",
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};
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static const struct tty_operations vcc_ops;
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#define VCC_TTY_FLAGS (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW)
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@ -127,11 +496,21 @@ static int __init vcc_init(void)
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return rv;
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}
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rv = vio_register_driver(&vcc_driver);
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if (rv) {
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pr_err("VCC: VIO driver registration failed\n");
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vcc_tty_exit();
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} else {
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vccdbg("VCC: VIO driver registered successfully\n");
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}
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return rv;
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}
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static void __exit vcc_exit(void)
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{
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vio_unregister_driver(&vcc_driver);
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vccdbg("VCC: VIO driver unregistered\n");
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vcc_tty_exit();
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vccdbg("VCC: TTY driver unregistered\n");
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}
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