[S390] s390/hvc_console: z/VM IUCV hypervisor console support
This patch introduces a new hypervisor console (HVC) back-end that provides terminal access over the z/VM inter-user communication vehicle (IUCV). The z/VM IUCV communication is independent of the regular tcp/ip network and allows access even if there is no network connection between two z/VM guest virtual machines. The z/VM IUCV hypervisor console back-end helps the user to access a z/VM guest virtual machine that lacks of network connectivity; and thus, provides a "full-screen" terminal alternative to 3215/3270 terminal sessions. Use the hvc_iucv=[0..8] kernel boot parameter to specify the number of HVC terminals using a z/VM IUCV back-end. A recent version of the s390-tools package is required to establish a terminal connection to a z/VM IUCV hypervisor console back-end. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Hendrik Brueckner
Martin Schwidefsky
parent
5d360a75f8
commit
44a01d5ba8
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@ -622,6 +622,16 @@ config HVC_BEAT
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help
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Toshiba's Cell Reference Set Beat Console device driver
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config HVC_IUCV
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bool "z/VM IUCV Hypervisor console support (VM only)"
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depends on S390
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select HVC_DRIVER
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select IUCV
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default y
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help
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This driver provides a Hypervisor console (HVC) back-end to access
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a Linux (console) terminal via a z/VM IUCV communication path.
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config HVC_XEN
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bool "Xen Hypervisor Console support"
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depends on XEN
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@ -50,6 +50,7 @@ obj-$(CONFIG_HVC_BEAT) += hvc_beat.o
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obj-$(CONFIG_HVC_DRIVER) += hvc_console.o
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obj-$(CONFIG_HVC_IRQ) += hvc_irq.o
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obj-$(CONFIG_HVC_XEN) += hvc_xen.o
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obj-$(CONFIG_HVC_IUCV) += hvc_iucv.o
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obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o
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obj-$(CONFIG_RAW_DRIVER) += raw.o
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obj-$(CONFIG_SGI_SNSC) += snsc.o snsc_event.o
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@ -0,0 +1,850 @@
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/*
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* hvc_iucv.c - z/VM IUCV back-end for the Hypervisor Console (HVC)
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*
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* This back-end for HVC provides terminal access via
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* z/VM IUCV communication paths.
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*
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* Copyright IBM Corp. 2008.
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*
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* Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
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*/
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#define KMSG_COMPONENT "hvc_iucv"
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#include <linux/types.h>
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#include <asm/ebcdic.h>
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#include <linux/mempool.h>
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#include <linux/module.h>
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#include <linux/tty.h>
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#include <net/iucv/iucv.h>
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#include "hvc_console.h"
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/* HVC backend for z/VM IUCV */
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#define HVC_IUCV_MAGIC 0xc9e4c3e5
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#define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS
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#define MEMPOOL_MIN_NR (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4)
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/* IUCV TTY message */
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#define MSG_VERSION 0x02 /* Message version */
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#define MSG_TYPE_ERROR 0x01 /* Error message */
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#define MSG_TYPE_TERMENV 0x02 /* Terminal environment variable */
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#define MSG_TYPE_TERMIOS 0x04 /* Terminal IO struct update */
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#define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */
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#define MSG_TYPE_DATA 0x10 /* Terminal data */
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#define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data))
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struct iucv_tty_msg {
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u8 version; /* Message version */
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u8 type; /* Message type */
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#define MSG_MAX_DATALEN (~(u16)0)
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u16 datalen; /* Payload length */
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u8 data[]; /* Payload buffer */
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} __attribute__((packed));
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enum iucv_state_t {
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IUCV_DISCONN = 0,
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IUCV_CONNECTED = 1,
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IUCV_SEVERED = 2,
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};
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enum tty_state_t {
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TTY_CLOSED = 0,
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TTY_OPENED = 1,
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};
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struct hvc_iucv_private {
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struct hvc_struct *hvc; /* HVC console struct reference */
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u8 srv_name[8]; /* IUCV service name (ebcdic) */
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enum iucv_state_t iucv_state; /* IUCV connection status */
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enum tty_state_t tty_state; /* TTY status */
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struct iucv_path *path; /* IUCV path pointer */
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spinlock_t lock; /* hvc_iucv_private lock */
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struct list_head tty_outqueue; /* outgoing IUCV messages */
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struct list_head tty_inqueue; /* incoming IUCV messages */
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};
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struct iucv_tty_buffer {
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struct list_head list; /* list pointer */
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struct iucv_message msg; /* store an incoming IUCV message */
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size_t offset; /* data buffer offset */
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struct iucv_tty_msg *mbuf; /* buffer to store input/output data */
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};
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/* IUCV callback handler */
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static int hvc_iucv_path_pending(struct iucv_path *, u8[8], u8[16]);
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static void hvc_iucv_path_severed(struct iucv_path *, u8[16]);
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static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *);
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static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *);
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/* Kernel module parameters */
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static unsigned long hvc_iucv_devices;
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/* Array of allocated hvc iucv tty lines... */
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static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES];
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/* Kmem cache and mempool for iucv_tty_buffer elements */
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static struct kmem_cache *hvc_iucv_buffer_cache;
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static mempool_t *hvc_iucv_mempool;
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/* IUCV handler callback functions */
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static struct iucv_handler hvc_iucv_handler = {
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.path_pending = hvc_iucv_path_pending,
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.path_severed = hvc_iucv_path_severed,
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.message_complete = hvc_iucv_msg_complete,
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.message_pending = hvc_iucv_msg_pending,
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};
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/**
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* hvc_iucv_get_private() - Return a struct hvc_iucv_private instance.
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* @num: The HVC virtual terminal number (vtermno)
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*
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* This function returns the struct hvc_iucv_private instance that corresponds
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* to the HVC virtual terminal number specified as parameter @num.
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*/
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struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num)
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{
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if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices))
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return NULL;
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return hvc_iucv_table[num - HVC_IUCV_MAGIC];
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}
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/**
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* alloc_tty_buffer() - Returns a new struct iucv_tty_buffer element.
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* @size: Size of the internal buffer used to store data.
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* @flags: Memory allocation flags passed to mempool.
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*
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* This function allocates a new struct iucv_tty_buffer element and, optionally,
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* allocates an internal data buffer with the specified size @size.
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* Note: The total message size arises from the internal buffer size and the
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* members of the iucv_tty_msg structure.
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*
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* The function returns NULL if memory allocation has failed.
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*/
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static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags)
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{
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struct iucv_tty_buffer *bufp;
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bufp = mempool_alloc(hvc_iucv_mempool, flags);
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if (!bufp)
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return NULL;
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memset(bufp, 0, sizeof(struct iucv_tty_buffer));
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if (size > 0) {
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bufp->msg.length = MSG_SIZE(size);
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bufp->mbuf = kmalloc(bufp->msg.length, flags);
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if (!bufp->mbuf) {
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mempool_free(bufp, hvc_iucv_mempool);
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return NULL;
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}
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bufp->mbuf->version = MSG_VERSION;
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bufp->mbuf->type = MSG_TYPE_DATA;
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bufp->mbuf->datalen = (u16) size;
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}
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return bufp;
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}
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/**
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* destroy_tty_buffer() - destroy struct iucv_tty_buffer element.
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* @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL.
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*
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* The destroy_tty_buffer() function frees the internal data buffer and returns
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* the struct iucv_tty_buffer element back to the mempool for freeing.
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*/
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static void destroy_tty_buffer(struct iucv_tty_buffer *bufp)
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{
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kfree(bufp->mbuf);
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mempool_free(bufp, hvc_iucv_mempool);
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}
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/**
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* destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element.
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* @list: List head pointer to a list containing struct iucv_tty_buffer
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* elements.
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*
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* Calls destroy_tty_buffer() for each struct iucv_tty_buffer element in the
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* list @list.
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*/
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static void destroy_tty_buffer_list(struct list_head *list)
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{
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struct iucv_tty_buffer *ent, *next;
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list_for_each_entry_safe(ent, next, list, list) {
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list_del(&ent->list);
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destroy_tty_buffer(ent);
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}
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}
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/**
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* hvc_iucv_write() - Receive IUCV message write data to HVC console buffer.
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* @priv: Pointer to hvc_iucv_private structure.
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* @buf: HVC console buffer for writing received terminal data.
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* @count: HVC console buffer size.
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* @has_more_data: Pointer to an int variable.
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*
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* The function picks up pending messages from the input queue and receives
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* the message data that is then written to the specified buffer @buf.
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* If the buffer size @count is less than the data message size, then the
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* message is kept on the input queue and @has_more_data is set to 1.
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* If the message data has been entirely written, the message is removed from
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* the input queue.
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*
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* The function returns the number of bytes written to the terminal, zero if
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* there are no pending data messages available or if there is no established
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* IUCV path.
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* If the IUCV path has been severed, then -EPIPE is returned to cause a
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* hang up (that is issued by the HVC console layer).
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*/
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static int hvc_iucv_write(struct hvc_iucv_private *priv,
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char *buf, int count, int *has_more_data)
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{
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struct iucv_tty_buffer *rb;
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int written;
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int rc;
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/* Immediately return if there is no IUCV connection */
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if (priv->iucv_state == IUCV_DISCONN)
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return 0;
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/* If the IUCV path has been severed, return -EPIPE to inform the
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* hvc console layer to hang up the tty device. */
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if (priv->iucv_state == IUCV_SEVERED)
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return -EPIPE;
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/* check if there are pending messages */
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if (list_empty(&priv->tty_inqueue))
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return 0;
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/* receive a iucv message and flip data to the tty (ldisc) */
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rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list);
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written = 0;
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if (!rb->mbuf) { /* message not yet received ... */
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/* allocate mem to store msg data; if no memory is available
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* then leave the buffer on the list and re-try later */
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rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC);
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if (!rb->mbuf)
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return -ENOMEM;
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rc = __iucv_message_receive(priv->path, &rb->msg, 0,
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rb->mbuf, rb->msg.length, NULL);
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switch (rc) {
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case 0: /* Successful */
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break;
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case 2: /* No message found */
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case 9: /* Message purged */
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break;
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default:
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written = -EIO;
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}
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/* remove buffer if an error has occured or received data
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* is not correct */
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if (rc || (rb->mbuf->version != MSG_VERSION) ||
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(rb->msg.length != MSG_SIZE(rb->mbuf->datalen)))
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goto out_remove_buffer;
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}
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switch (rb->mbuf->type) {
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case MSG_TYPE_DATA:
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written = min_t(int, rb->mbuf->datalen - rb->offset, count);
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memcpy(buf, rb->mbuf->data + rb->offset, written);
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if (written < (rb->mbuf->datalen - rb->offset)) {
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rb->offset += written;
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*has_more_data = 1;
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goto out_written;
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}
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break;
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case MSG_TYPE_WINSIZE:
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if (rb->mbuf->datalen != sizeof(struct winsize))
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break;
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hvc_resize(priv->hvc, *((struct winsize *)rb->mbuf->data));
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break;
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case MSG_TYPE_ERROR: /* ignored ... */
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case MSG_TYPE_TERMENV: /* ignored ... */
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case MSG_TYPE_TERMIOS: /* ignored ... */
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break;
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}
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out_remove_buffer:
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list_del(&rb->list);
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destroy_tty_buffer(rb);
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*has_more_data = !list_empty(&priv->tty_inqueue);
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out_written:
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return written;
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}
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/**
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* hvc_iucv_get_chars() - HVC get_chars operation.
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* @vtermno: HVC virtual terminal number.
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* @buf: Pointer to a buffer to store data
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* @count: Size of buffer available for writing
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*
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* The hvc_console thread calls this method to read characters from
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* the terminal backend. If an IUCV communication path has been established,
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* pending IUCV messages are received and data is copied into buffer @buf
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* up to @count bytes.
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*
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* Locking: The routine gets called under an irqsave() spinlock; and
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* the routine locks the struct hvc_iucv_private->lock to call
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* helper functions.
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*/
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static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count)
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{
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struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
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int written;
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int has_more_data;
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if (count <= 0)
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return 0;
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if (!priv)
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return -ENODEV;
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spin_lock(&priv->lock);
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has_more_data = 0;
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written = hvc_iucv_write(priv, buf, count, &has_more_data);
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spin_unlock(&priv->lock);
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/* if there are still messages on the queue... schedule another run */
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if (has_more_data)
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hvc_kick();
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return written;
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}
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/**
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* hvc_iucv_send() - Send an IUCV message containing terminal data.
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* @priv: Pointer to struct hvc_iucv_private instance.
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* @buf: Buffer containing data to send.
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* @size: Size of buffer and amount of data to send.
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*
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* If an IUCV communication path is established, the function copies the buffer
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* data to a newly allocated struct iucv_tty_buffer element, sends the data and
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* puts the element to the outqueue.
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*
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* If there is no IUCV communication path established, the function returns 0.
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* If an existing IUCV communicaton path has been severed, the function returns
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* -EPIPE (can be passed to HVC layer to cause a tty hangup).
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*/
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static int hvc_iucv_send(struct hvc_iucv_private *priv, const char *buf,
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int count)
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{
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struct iucv_tty_buffer *sb;
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int rc;
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u16 len;
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if (priv->iucv_state == IUCV_SEVERED)
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return -EPIPE;
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if (priv->iucv_state == IUCV_DISCONN)
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return 0;
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len = min_t(u16, MSG_MAX_DATALEN, count);
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/* allocate internal buffer to store msg data and also compute total
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* message length */
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sb = alloc_tty_buffer(len, GFP_ATOMIC);
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if (!sb)
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return -ENOMEM;
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sb->mbuf->datalen = len;
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memcpy(sb->mbuf->data, buf, len);
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list_add_tail(&sb->list, &priv->tty_outqueue);
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rc = __iucv_message_send(priv->path, &sb->msg, 0, 0,
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(void *) sb->mbuf, sb->msg.length);
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if (rc) {
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list_del(&sb->list);
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destroy_tty_buffer(sb);
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len = 0;
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}
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return len;
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}
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/**
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* hvc_iucv_put_chars() - HVC put_chars operation.
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* @vtermno: HVC virtual terminal number.
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* @buf: Pointer to an buffer to read data from
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* @count: Size of buffer available for reading
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*
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* The hvc_console thread calls this method to write characters from
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* to the terminal backend.
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* The function calls hvc_iucv_send() under the lock of the
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* struct hvc_iucv_private instance that corresponds to the tty @vtermno.
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*
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* Locking: The method gets called under an irqsave() spinlock; and
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* locks struct hvc_iucv_private->lock.
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*/
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static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count)
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{
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struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
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int sent;
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if (count <= 0)
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return 0;
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if (!priv)
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return -ENODEV;
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spin_lock(&priv->lock);
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sent = hvc_iucv_send(priv, buf, count);
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spin_unlock(&priv->lock);
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return sent;
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}
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/**
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* hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time.
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* @hp: Pointer to the HVC device (struct hvc_struct)
|
||||
* @id: Additional data (originally passed to hvc_alloc): the index of an struct
|
||||
* hvc_iucv_private instance.
|
||||
*
|
||||
* The function sets the tty state to TTY_OPEN for the struct hvc_iucv_private
|
||||
* instance that is derived from @id. Always returns 0.
|
||||
*
|
||||
* Locking: struct hvc_iucv_private->lock, spin_lock_bh
|
||||
*/
|
||||
static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id)
|
||||
{
|
||||
struct hvc_iucv_private *priv;
|
||||
|
||||
priv = hvc_iucv_get_private(id);
|
||||
if (!priv)
|
||||
return 0;
|
||||
|
||||
spin_lock_bh(&priv->lock);
|
||||
priv->tty_state = TTY_OPENED;
|
||||
spin_unlock_bh(&priv->lock);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* hvc_iucv_cleanup() - Clean up function if the tty portion is finally closed.
|
||||
* @priv: Pointer to the struct hvc_iucv_private instance.
|
||||
*
|
||||
* The functions severs the established IUCV communication path (if any), and
|
||||
* destroy struct iucv_tty_buffer elements from the in- and outqueue. Finally,
|
||||
* the functions resets the states to TTY_CLOSED and IUCV_DISCONN.
|
||||
*/
|
||||
static void hvc_iucv_cleanup(struct hvc_iucv_private *priv)
|
||||
{
|
||||
destroy_tty_buffer_list(&priv->tty_outqueue);
|
||||
destroy_tty_buffer_list(&priv->tty_inqueue);
|
||||
|
||||
priv->tty_state = TTY_CLOSED;
|
||||
priv->iucv_state = IUCV_DISCONN;
|
||||
}
|
||||
|
||||
/**
|
||||
* hvc_iucv_notifier_hangup() - HVC notifier for tty hangups.
|
||||
* @hp: Pointer to the HVC device (struct hvc_struct)
|
||||
* @id: Additional data (originally passed to hvc_alloc): the index of an struct
|
||||
* hvc_iucv_private instance.
|
||||
*
|
||||
* This routine notifies the HVC backend that a tty hangup (carrier loss,
|
||||
* virtual or otherwise) has occured.
|
||||
*
|
||||
* The HVC backend for z/VM IUCV ignores virtual hangups (vhangup()), to keep
|
||||
* an existing IUCV communication path established.
|
||||
* (Background: vhangup() is called from user space (by getty or login) to
|
||||
* disable writing to the tty by other applications).
|
||||
*
|
||||
* If the tty has been opened (e.g. getty) and an established IUCV path has been
|
||||
* severed (we caused the tty hangup in that case), then the functions invokes
|
||||
* hvc_iucv_cleanup() to clean up.
|
||||
*
|
||||
* Locking: struct hvc_iucv_private->lock
|
||||
*/
|
||||
static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
|
||||
{
|
||||
struct hvc_iucv_private *priv;
|
||||
|
||||
priv = hvc_iucv_get_private(id);
|
||||
if (!priv)
|
||||
return;
|
||||
|
||||
spin_lock_bh(&priv->lock);
|
||||
/* NOTE: If the hangup was scheduled by ourself (from the iucv
|
||||
* path_servered callback [IUCV_SEVERED]), then we have to
|
||||
* finally clean up the tty backend structure and set state to
|
||||
* TTY_CLOSED.
|
||||
*
|
||||
* If the tty was hung up otherwise (e.g. vhangup()), then we
|
||||
* ignore this hangup and keep an established IUCV path open...
|
||||
* (...the reason is that we are not able to connect back to the
|
||||
* client if we disconnect on hang up) */
|
||||
priv->tty_state = TTY_CLOSED;
|
||||
|
||||
if (priv->iucv_state == IUCV_SEVERED)
|
||||
hvc_iucv_cleanup(priv);
|
||||
spin_unlock_bh(&priv->lock);
|
||||
}
|
||||
|
||||
/**
|
||||
* hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.
|
||||
* @hp: Pointer to the HVC device (struct hvc_struct)
|
||||
* @id: Additional data (originally passed to hvc_alloc):
|
||||
* the index of an struct hvc_iucv_private instance.
|
||||
*
|
||||
* This routine notifies the HVC backend that the last tty device file
|
||||
* descriptor has been closed.
|
||||
* The function calls hvc_iucv_cleanup() to clean up the struct hvc_iucv_private
|
||||
* instance.
|
||||
*
|
||||
* Locking: struct hvc_iucv_private->lock
|
||||
*/
|
||||
static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
|
||||
{
|
||||
struct hvc_iucv_private *priv;
|
||||
struct iucv_path *path;
|
||||
|
||||
priv = hvc_iucv_get_private(id);
|
||||
if (!priv)
|
||||
return;
|
||||
|
||||
spin_lock_bh(&priv->lock);
|
||||
path = priv->path; /* save reference to IUCV path */
|
||||
priv->path = NULL;
|
||||
hvc_iucv_cleanup(priv);
|
||||
spin_unlock_bh(&priv->lock);
|
||||
|
||||
/* sever IUCV path outside of priv->lock due to lock ordering of:
|
||||
* priv->lock <--> iucv_table_lock */
|
||||
if (path) {
|
||||
iucv_path_sever(path, NULL);
|
||||
iucv_path_free(path);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* hvc_iucv_path_pending() - IUCV handler to process a connection request.
|
||||
* @path: Pending path (struct iucv_path)
|
||||
* @ipvmid: Originator z/VM system identifier
|
||||
* @ipuser: User specified data for this path
|
||||
* (AF_IUCV: port/service name and originator port)
|
||||
*
|
||||
* The function uses the @ipuser data to check to determine if the pending
|
||||
* path belongs to a terminal managed by this HVC backend.
|
||||
* If the check is successful, then an additional check is done to ensure
|
||||
* that a terminal cannot be accessed multiple times (only one connection
|
||||
* to a terminal is allowed). In that particular case, the pending path is
|
||||
* severed. If it is the first connection, the pending path is accepted and
|
||||
* associated to the struct hvc_iucv_private. The iucv state is updated to
|
||||
* reflect that a communication path has been established.
|
||||
*
|
||||
* Returns 0 if the path belongs to a terminal managed by the this HVC backend;
|
||||
* otherwise returns -ENODEV in order to dispatch this path to other handlers.
|
||||
*
|
||||
* Locking: struct hvc_iucv_private->lock
|
||||
*/
|
||||
static int hvc_iucv_path_pending(struct iucv_path *path,
|
||||
u8 ipvmid[8], u8 ipuser[16])
|
||||
{
|
||||
struct hvc_iucv_private *priv;
|
||||
u8 nuser_data[16];
|
||||
int i, rc;
|
||||
|
||||
priv = NULL;
|
||||
for (i = 0; i < hvc_iucv_devices; i++)
|
||||
if (hvc_iucv_table[i] &&
|
||||
(0 == memcmp(hvc_iucv_table[i]->srv_name, ipuser, 8))) {
|
||||
priv = hvc_iucv_table[i];
|
||||
break;
|
||||
}
|
||||
|
||||
if (!priv)
|
||||
return -ENODEV;
|
||||
|
||||
spin_lock(&priv->lock);
|
||||
|
||||
/* If the terminal is already connected or being severed, then sever
|
||||
* this path to enforce that there is only ONE established communication
|
||||
* path per terminal. */
|
||||
if (priv->iucv_state != IUCV_DISCONN) {
|
||||
iucv_path_sever(path, ipuser);
|
||||
iucv_path_free(path);
|
||||
goto out_path_handled;
|
||||
}
|
||||
|
||||
/* accept path */
|
||||
memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */
|
||||
memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */
|
||||
path->msglim = 0xffff; /* IUCV MSGLIMIT */
|
||||
path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */
|
||||
rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv);
|
||||
if (rc) {
|
||||
iucv_path_sever(path, ipuser);
|
||||
iucv_path_free(path);
|
||||
goto out_path_handled;
|
||||
}
|
||||
priv->path = path;
|
||||
priv->iucv_state = IUCV_CONNECTED;
|
||||
|
||||
out_path_handled:
|
||||
spin_unlock(&priv->lock);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* hvc_iucv_path_severed() - IUCV handler to process a path sever.
|
||||
* @path: Pending path (struct iucv_path)
|
||||
* @ipuser: User specified data for this path
|
||||
* (AF_IUCV: port/service name and originator port)
|
||||
*
|
||||
* The function also severs the path (as required by the IUCV protocol) and
|
||||
* sets the iucv state to IUCV_SEVERED for the associated struct
|
||||
* hvc_iucv_private instance. Later, the IUCV_SEVERED state triggers a tty
|
||||
* hangup (hvc_iucv_get_chars() / hvc_iucv_write()).
|
||||
*
|
||||
* If tty portion of the HVC is closed then clean up the outqueue in addition.
|
||||
*
|
||||
* Locking: struct hvc_iucv_private->lock
|
||||
*/
|
||||
static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16])
|
||||
{
|
||||
struct hvc_iucv_private *priv = path->private;
|
||||
|
||||
spin_lock(&priv->lock);
|
||||
priv->iucv_state = IUCV_SEVERED;
|
||||
|
||||
/* NOTE: If the tty has not yet been opened by a getty program
|
||||
* (e.g. to see console messages), then cleanup the
|
||||
* hvc_iucv_private structure to allow re-connects.
|
||||
*
|
||||
* If the tty has been opened, the get_chars() callback returns
|
||||
* -EPIPE to signal the hvc console layer to hang up the tty. */
|
||||
priv->path = NULL;
|
||||
if (priv->tty_state == TTY_CLOSED)
|
||||
hvc_iucv_cleanup(priv);
|
||||
spin_unlock(&priv->lock);
|
||||
|
||||
/* finally sever path (outside of priv->lock due to lock ordering) */
|
||||
iucv_path_sever(path, ipuser);
|
||||
iucv_path_free(path);
|
||||
}
|
||||
|
||||
/**
|
||||
* hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message.
|
||||
* @path: Pending path (struct iucv_path)
|
||||
* @msg: Pointer to the IUCV message
|
||||
*
|
||||
* The function stores an incoming message on the input queue for later
|
||||
* processing (by hvc_iucv_get_chars() / hvc_iucv_write()).
|
||||
* However, if the tty has not yet been opened, the message is rejected.
|
||||
*
|
||||
* Locking: struct hvc_iucv_private->lock
|
||||
*/
|
||||
static void hvc_iucv_msg_pending(struct iucv_path *path,
|
||||
struct iucv_message *msg)
|
||||
{
|
||||
struct hvc_iucv_private *priv = path->private;
|
||||
struct iucv_tty_buffer *rb;
|
||||
|
||||
spin_lock(&priv->lock);
|
||||
|
||||
/* reject messages if tty has not yet been opened */
|
||||
if (priv->tty_state == TTY_CLOSED) {
|
||||
iucv_message_reject(path, msg);
|
||||
goto unlock_return;
|
||||
}
|
||||
|
||||
/* allocate buffer an empty buffer element */
|
||||
rb = alloc_tty_buffer(0, GFP_ATOMIC);
|
||||
if (!rb) {
|
||||
iucv_message_reject(path, msg);
|
||||
goto unlock_return; /* -ENOMEM */
|
||||
}
|
||||
rb->msg = *msg;
|
||||
|
||||
list_add_tail(&rb->list, &priv->tty_inqueue);
|
||||
|
||||
hvc_kick(); /* wakup hvc console thread */
|
||||
|
||||
unlock_return:
|
||||
spin_unlock(&priv->lock);
|
||||
}
|
||||
|
||||
/**
|
||||
* hvc_iucv_msg_complete() - IUCV handler to process message completion
|
||||
* @path: Pending path (struct iucv_path)
|
||||
* @msg: Pointer to the IUCV message
|
||||
*
|
||||
* The function is called upon completion of message delivery and the
|
||||
* message is removed from the outqueue. Additional delivery information
|
||||
* can be found in msg->audit: rejected messages (0x040000 (IPADRJCT)) and
|
||||
* purged messages (0x010000 (IPADPGNR)).
|
||||
*
|
||||
* Locking: struct hvc_iucv_private->lock
|
||||
*/
|
||||
static void hvc_iucv_msg_complete(struct iucv_path *path,
|
||||
struct iucv_message *msg)
|
||||
{
|
||||
struct hvc_iucv_private *priv = path->private;
|
||||
struct iucv_tty_buffer *ent, *next;
|
||||
LIST_HEAD(list_remove);
|
||||
|
||||
spin_lock(&priv->lock);
|
||||
list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list)
|
||||
if (ent->msg.id == msg->id) {
|
||||
list_move(&ent->list, &list_remove);
|
||||
break;
|
||||
}
|
||||
spin_unlock(&priv->lock);
|
||||
destroy_tty_buffer_list(&list_remove);
|
||||
}
|
||||
|
||||
|
||||
/* HVC operations */
|
||||
static struct hv_ops hvc_iucv_ops = {
|
||||
.get_chars = hvc_iucv_get_chars,
|
||||
.put_chars = hvc_iucv_put_chars,
|
||||
.notifier_add = hvc_iucv_notifier_add,
|
||||
.notifier_del = hvc_iucv_notifier_del,
|
||||
.notifier_hangup = hvc_iucv_notifier_hangup,
|
||||
};
|
||||
|
||||
/**
|
||||
* hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance
|
||||
* @id: hvc_iucv_table index
|
||||
*
|
||||
* This function allocates a new hvc_iucv_private struct and put the
|
||||
* instance into hvc_iucv_table at index @id.
|
||||
* Returns 0 on success; otherwise non-zero.
|
||||
*/
|
||||
static int __init hvc_iucv_alloc(int id)
|
||||
{
|
||||
struct hvc_iucv_private *priv;
|
||||
char name[9];
|
||||
int rc;
|
||||
|
||||
priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL);
|
||||
if (!priv)
|
||||
return -ENOMEM;
|
||||
|
||||
spin_lock_init(&priv->lock);
|
||||
INIT_LIST_HEAD(&priv->tty_outqueue);
|
||||
INIT_LIST_HEAD(&priv->tty_inqueue);
|
||||
|
||||
/* Finally allocate hvc */
|
||||
priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id,
|
||||
HVC_IUCV_MAGIC + id, &hvc_iucv_ops, PAGE_SIZE);
|
||||
if (IS_ERR(priv->hvc)) {
|
||||
rc = PTR_ERR(priv->hvc);
|
||||
kfree(priv);
|
||||
return rc;
|
||||
}
|
||||
|
||||
/* setup iucv related information */
|
||||
snprintf(name, 9, "ihvc%-4d", id);
|
||||
memcpy(priv->srv_name, name, 8);
|
||||
ASCEBC(priv->srv_name, 8);
|
||||
|
||||
hvc_iucv_table[id] = priv;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* hvc_iucv_init() - Initialization of HVC backend for z/VM IUCV
|
||||
*/
|
||||
static int __init hvc_iucv_init(void)
|
||||
{
|
||||
int rc, i;
|
||||
|
||||
if (!MACHINE_IS_VM) {
|
||||
pr_warning("The z/VM IUCV Hypervisor console cannot be "
|
||||
"used without z/VM.\n");
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
if (!hvc_iucv_devices)
|
||||
return -ENODEV;
|
||||
|
||||
if (hvc_iucv_devices > MAX_HVC_IUCV_LINES)
|
||||
return -EINVAL;
|
||||
|
||||
hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT,
|
||||
sizeof(struct iucv_tty_buffer),
|
||||
0, 0, NULL);
|
||||
if (!hvc_iucv_buffer_cache) {
|
||||
pr_err("Not enough memory for driver initialization "
|
||||
"(rs=%d).\n", 1);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR,
|
||||
hvc_iucv_buffer_cache);
|
||||
if (!hvc_iucv_mempool) {
|
||||
pr_err("Not enough memory for driver initialization "
|
||||
"(rs=%d).\n", 2);
|
||||
kmem_cache_destroy(hvc_iucv_buffer_cache);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
/* allocate hvc_iucv_private structs */
|
||||
for (i = 0; i < hvc_iucv_devices; i++) {
|
||||
rc = hvc_iucv_alloc(i);
|
||||
if (rc) {
|
||||
pr_err("Could not create new z/VM IUCV HVC backend "
|
||||
"rc=%d.\n", rc);
|
||||
goto out_error_hvc;
|
||||
}
|
||||
}
|
||||
|
||||
/* register IUCV callback handler */
|
||||
rc = iucv_register(&hvc_iucv_handler, 0);
|
||||
if (rc) {
|
||||
pr_err("Could not register iucv handler (rc=%d).\n", rc);
|
||||
goto out_error_iucv;
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
||||
out_error_iucv:
|
||||
iucv_unregister(&hvc_iucv_handler, 0);
|
||||
out_error_hvc:
|
||||
for (i = 0; i < hvc_iucv_devices; i++)
|
||||
if (hvc_iucv_table[i]) {
|
||||
if (hvc_iucv_table[i]->hvc)
|
||||
hvc_remove(hvc_iucv_table[i]->hvc);
|
||||
kfree(hvc_iucv_table[i]);
|
||||
}
|
||||
mempool_destroy(hvc_iucv_mempool);
|
||||
kmem_cache_destroy(hvc_iucv_buffer_cache);
|
||||
return rc;
|
||||
}
|
||||
|
||||
/**
|
||||
* hvc_iucv_console_init() - Early console initialization
|
||||
*/
|
||||
static int __init hvc_iucv_console_init(void)
|
||||
{
|
||||
if (!MACHINE_IS_VM || !hvc_iucv_devices)
|
||||
return -ENODEV;
|
||||
return hvc_instantiate(HVC_IUCV_MAGIC, 0, &hvc_iucv_ops);
|
||||
}
|
||||
|
||||
/**
|
||||
* hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter
|
||||
* @val: Parameter value (numeric)
|
||||
*/
|
||||
static int __init hvc_iucv_config(char *val)
|
||||
{
|
||||
return strict_strtoul(val, 10, &hvc_iucv_devices);
|
||||
}
|
||||
|
||||
|
||||
module_init(hvc_iucv_init);
|
||||
console_initcall(hvc_iucv_console_init);
|
||||
__setup("hvc_iucv=", hvc_iucv_config);
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_DESCRIPTION("HVC back-end for z/VM IUCV.");
|
||||
MODULE_AUTHOR("Hendrik Brueckner <brueckner@linux.vnet.ibm.com>");
|
||||
Loading…
Reference in New Issue