![Dan Carpenter](/assets/img/avatar_default.png)
If kzalloc() returns a NULL here, we pass a NULL to xencons_disconnect_backend() which will cause an Oops. Also I removed the __GFP_ZERO while I was at it since kzalloc() implies __GFP_ZERO. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
653 lines
14 KiB
C
653 lines
14 KiB
C
/*
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* xen console driver interface to hvc_console.c
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*
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* (c) 2007 Gerd Hoffmann <kraxel@suse.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/console.h>
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/types.h>
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#include <linux/list.h>
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#include <asm/io.h>
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#include <asm/xen/hypervisor.h>
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#include <xen/xen.h>
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#include <xen/interface/xen.h>
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#include <xen/hvm.h>
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#include <xen/grant_table.h>
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#include <xen/page.h>
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#include <xen/events.h>
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#include <xen/interface/io/console.h>
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#include <xen/hvc-console.h>
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#include <xen/xenbus.h>
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#include "hvc_console.h"
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#define HVC_COOKIE 0x58656e /* "Xen" in hex */
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struct xencons_info {
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struct list_head list;
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struct xenbus_device *xbdev;
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struct xencons_interface *intf;
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unsigned int evtchn;
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struct hvc_struct *hvc;
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int irq;
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int vtermno;
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grant_ref_t gntref;
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};
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static LIST_HEAD(xenconsoles);
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static DEFINE_SPINLOCK(xencons_lock);
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/* ------------------------------------------------------------------ */
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static struct xencons_info *vtermno_to_xencons(int vtermno)
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{
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struct xencons_info *entry, *n, *ret = NULL;
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if (list_empty(&xenconsoles))
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return NULL;
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list_for_each_entry_safe(entry, n, &xenconsoles, list) {
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if (entry->vtermno == vtermno) {
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ret = entry;
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break;
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}
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}
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return ret;
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}
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static inline int xenbus_devid_to_vtermno(int devid)
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{
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return devid + HVC_COOKIE;
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}
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static inline void notify_daemon(struct xencons_info *cons)
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{
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/* Use evtchn: this is called early, before irq is set up. */
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notify_remote_via_evtchn(cons->evtchn);
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}
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static int __write_console(struct xencons_info *xencons,
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const char *data, int len)
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{
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XENCONS_RING_IDX cons, prod;
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struct xencons_interface *intf = xencons->intf;
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int sent = 0;
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cons = intf->out_cons;
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prod = intf->out_prod;
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mb(); /* update queue values before going on */
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BUG_ON((prod - cons) > sizeof(intf->out));
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while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
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intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++];
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wmb(); /* write ring before updating pointer */
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intf->out_prod = prod;
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if (sent)
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notify_daemon(xencons);
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return sent;
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}
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static int domU_write_console(uint32_t vtermno, const char *data, int len)
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{
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int ret = len;
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struct xencons_info *cons = vtermno_to_xencons(vtermno);
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if (cons == NULL)
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return -EINVAL;
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/*
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* Make sure the whole buffer is emitted, polling if
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* necessary. We don't ever want to rely on the hvc daemon
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* because the most interesting console output is when the
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* kernel is crippled.
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*/
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while (len) {
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int sent = __write_console(cons, data, len);
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data += sent;
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len -= sent;
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if (unlikely(len))
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HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
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}
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return ret;
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}
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static int domU_read_console(uint32_t vtermno, char *buf, int len)
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{
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struct xencons_interface *intf;
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XENCONS_RING_IDX cons, prod;
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int recv = 0;
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struct xencons_info *xencons = vtermno_to_xencons(vtermno);
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if (xencons == NULL)
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return -EINVAL;
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intf = xencons->intf;
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cons = intf->in_cons;
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prod = intf->in_prod;
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mb(); /* get pointers before reading ring */
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BUG_ON((prod - cons) > sizeof(intf->in));
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while (cons != prod && recv < len)
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buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];
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mb(); /* read ring before consuming */
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intf->in_cons = cons;
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notify_daemon(xencons);
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return recv;
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}
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static struct hv_ops domU_hvc_ops = {
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.get_chars = domU_read_console,
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.put_chars = domU_write_console,
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.notifier_add = notifier_add_irq,
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.notifier_del = notifier_del_irq,
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.notifier_hangup = notifier_hangup_irq,
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};
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static int dom0_read_console(uint32_t vtermno, char *buf, int len)
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{
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return HYPERVISOR_console_io(CONSOLEIO_read, len, buf);
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}
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/*
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* Either for a dom0 to write to the system console, or a domU with a
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* debug version of Xen
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*/
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static int dom0_write_console(uint32_t vtermno, const char *str, int len)
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{
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int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str);
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if (rc < 0)
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return 0;
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return len;
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}
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static struct hv_ops dom0_hvc_ops = {
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.get_chars = dom0_read_console,
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.put_chars = dom0_write_console,
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.notifier_add = notifier_add_irq,
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.notifier_del = notifier_del_irq,
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.notifier_hangup = notifier_hangup_irq,
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};
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static int xen_hvm_console_init(void)
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{
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int r;
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uint64_t v = 0;
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unsigned long mfn;
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struct xencons_info *info;
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if (!xen_hvm_domain())
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return -ENODEV;
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info = vtermno_to_xencons(HVC_COOKIE);
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if (!info) {
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info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
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if (!info)
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return -ENOMEM;
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}
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/* already configured */
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if (info->intf != NULL)
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return 0;
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r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
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if (r < 0) {
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kfree(info);
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return -ENODEV;
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}
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info->evtchn = v;
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hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
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if (r < 0) {
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kfree(info);
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return -ENODEV;
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}
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mfn = v;
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info->intf = ioremap(mfn << PAGE_SHIFT, PAGE_SIZE);
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if (info->intf == NULL) {
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kfree(info);
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return -ENODEV;
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}
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info->vtermno = HVC_COOKIE;
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spin_lock(&xencons_lock);
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list_add_tail(&info->list, &xenconsoles);
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spin_unlock(&xencons_lock);
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return 0;
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}
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static int xen_pv_console_init(void)
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{
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struct xencons_info *info;
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if (!xen_pv_domain())
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return -ENODEV;
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if (!xen_start_info->console.domU.evtchn)
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return -ENODEV;
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info = vtermno_to_xencons(HVC_COOKIE);
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if (!info) {
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info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
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if (!info)
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return -ENOMEM;
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}
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/* already configured */
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if (info->intf != NULL)
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return 0;
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info->evtchn = xen_start_info->console.domU.evtchn;
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info->intf = mfn_to_virt(xen_start_info->console.domU.mfn);
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info->vtermno = HVC_COOKIE;
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spin_lock(&xencons_lock);
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list_add_tail(&info->list, &xenconsoles);
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spin_unlock(&xencons_lock);
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return 0;
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}
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static int xen_initial_domain_console_init(void)
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{
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struct xencons_info *info;
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if (!xen_initial_domain())
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return -ENODEV;
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info = vtermno_to_xencons(HVC_COOKIE);
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if (!info) {
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info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
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if (!info)
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return -ENOMEM;
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}
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info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0);
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info->vtermno = HVC_COOKIE;
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spin_lock(&xencons_lock);
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list_add_tail(&info->list, &xenconsoles);
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spin_unlock(&xencons_lock);
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return 0;
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}
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void xen_console_resume(void)
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{
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struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE);
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if (info != NULL && info->irq)
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rebind_evtchn_irq(info->evtchn, info->irq);
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}
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static void xencons_disconnect_backend(struct xencons_info *info)
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{
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if (info->irq > 0)
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unbind_from_irqhandler(info->irq, NULL);
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info->irq = 0;
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if (info->evtchn > 0)
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xenbus_free_evtchn(info->xbdev, info->evtchn);
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info->evtchn = 0;
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if (info->gntref > 0)
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gnttab_free_grant_references(info->gntref);
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info->gntref = 0;
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if (info->hvc != NULL)
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hvc_remove(info->hvc);
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info->hvc = NULL;
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}
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static void xencons_free(struct xencons_info *info)
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{
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free_page((unsigned long)info->intf);
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info->intf = NULL;
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info->vtermno = 0;
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kfree(info);
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}
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static int xen_console_remove(struct xencons_info *info)
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{
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xencons_disconnect_backend(info);
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spin_lock(&xencons_lock);
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list_del(&info->list);
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spin_unlock(&xencons_lock);
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if (info->xbdev != NULL)
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xencons_free(info);
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else {
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if (xen_hvm_domain())
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iounmap(info->intf);
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kfree(info);
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}
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return 0;
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}
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#ifdef CONFIG_HVC_XEN_FRONTEND
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static struct xenbus_driver xencons_driver;
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static int xencons_remove(struct xenbus_device *dev)
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{
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return xen_console_remove(dev_get_drvdata(&dev->dev));
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}
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static int xencons_connect_backend(struct xenbus_device *dev,
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struct xencons_info *info)
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{
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int ret, evtchn, devid, ref, irq;
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struct xenbus_transaction xbt;
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grant_ref_t gref_head;
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unsigned long mfn;
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ret = xenbus_alloc_evtchn(dev, &evtchn);
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if (ret)
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return ret;
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info->evtchn = evtchn;
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irq = bind_evtchn_to_irq(evtchn);
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if (irq < 0)
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return irq;
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info->irq = irq;
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devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
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info->hvc = hvc_alloc(xenbus_devid_to_vtermno(devid),
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irq, &domU_hvc_ops, 256);
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if (IS_ERR(info->hvc))
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return PTR_ERR(info->hvc);
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if (xen_pv_domain())
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mfn = virt_to_mfn(info->intf);
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else
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mfn = __pa(info->intf) >> PAGE_SHIFT;
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ret = gnttab_alloc_grant_references(1, &gref_head);
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if (ret < 0)
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return ret;
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info->gntref = gref_head;
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ref = gnttab_claim_grant_reference(&gref_head);
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if (ref < 0)
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return ref;
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gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id,
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mfn, 0);
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again:
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ret = xenbus_transaction_start(&xbt);
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if (ret) {
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xenbus_dev_fatal(dev, ret, "starting transaction");
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return ret;
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}
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ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", ref);
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if (ret)
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goto error_xenbus;
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ret = xenbus_printf(xbt, dev->nodename, "port", "%u",
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evtchn);
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if (ret)
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goto error_xenbus;
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ret = xenbus_printf(xbt, dev->nodename, "type", "ioemu");
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if (ret)
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goto error_xenbus;
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ret = xenbus_transaction_end(xbt, 0);
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if (ret) {
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if (ret == -EAGAIN)
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goto again;
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xenbus_dev_fatal(dev, ret, "completing transaction");
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return ret;
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}
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xenbus_switch_state(dev, XenbusStateInitialised);
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return 0;
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error_xenbus:
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xenbus_transaction_end(xbt, 1);
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xenbus_dev_fatal(dev, ret, "writing xenstore");
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return ret;
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}
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static int __devinit xencons_probe(struct xenbus_device *dev,
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const struct xenbus_device_id *id)
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{
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int ret, devid;
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struct xencons_info *info;
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devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
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if (devid == 0)
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return -ENODEV;
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info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
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if (!info)
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return -ENOMEM;
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dev_set_drvdata(&dev->dev, info);
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info->xbdev = dev;
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info->vtermno = xenbus_devid_to_vtermno(devid);
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info->intf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
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if (!info->intf)
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goto error_nomem;
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ret = xencons_connect_backend(dev, info);
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if (ret < 0)
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goto error;
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spin_lock(&xencons_lock);
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list_add_tail(&info->list, &xenconsoles);
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spin_unlock(&xencons_lock);
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return 0;
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error_nomem:
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ret = -ENOMEM;
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xenbus_dev_fatal(dev, ret, "allocating device memory");
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error:
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xencons_disconnect_backend(info);
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xencons_free(info);
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return ret;
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}
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static int xencons_resume(struct xenbus_device *dev)
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{
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struct xencons_info *info = dev_get_drvdata(&dev->dev);
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xencons_disconnect_backend(info);
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memset(info->intf, 0, PAGE_SIZE);
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return xencons_connect_backend(dev, info);
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}
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static void xencons_backend_changed(struct xenbus_device *dev,
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enum xenbus_state backend_state)
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{
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switch (backend_state) {
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case XenbusStateReconfiguring:
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case XenbusStateReconfigured:
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case XenbusStateInitialising:
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case XenbusStateInitialised:
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case XenbusStateUnknown:
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case XenbusStateClosed:
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break;
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case XenbusStateInitWait:
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break;
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case XenbusStateConnected:
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xenbus_switch_state(dev, XenbusStateConnected);
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break;
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case XenbusStateClosing:
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xenbus_frontend_closed(dev);
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break;
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}
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}
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static const struct xenbus_device_id xencons_ids[] = {
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{ "console" },
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{ "" }
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};
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static DEFINE_XENBUS_DRIVER(xencons, "xenconsole",
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.probe = xencons_probe,
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.remove = xencons_remove,
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.resume = xencons_resume,
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.otherend_changed = xencons_backend_changed,
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);
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#endif /* CONFIG_HVC_XEN_FRONTEND */
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static int __init xen_hvc_init(void)
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{
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int r;
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struct xencons_info *info;
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const struct hv_ops *ops;
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if (!xen_domain())
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return -ENODEV;
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if (xen_initial_domain()) {
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ops = &dom0_hvc_ops;
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r = xen_initial_domain_console_init();
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if (r < 0)
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return r;
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info = vtermno_to_xencons(HVC_COOKIE);
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} else {
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ops = &domU_hvc_ops;
|
|
if (xen_hvm_domain())
|
|
r = xen_hvm_console_init();
|
|
else
|
|
r = xen_pv_console_init();
|
|
if (r < 0)
|
|
return r;
|
|
|
|
info = vtermno_to_xencons(HVC_COOKIE);
|
|
info->irq = bind_evtchn_to_irq(info->evtchn);
|
|
}
|
|
if (info->irq < 0)
|
|
info->irq = 0; /* NO_IRQ */
|
|
else
|
|
irq_set_noprobe(info->irq);
|
|
|
|
info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256);
|
|
if (IS_ERR(info->hvc)) {
|
|
r = PTR_ERR(info->hvc);
|
|
spin_lock(&xencons_lock);
|
|
list_del(&info->list);
|
|
spin_unlock(&xencons_lock);
|
|
if (info->irq)
|
|
unbind_from_irqhandler(info->irq, NULL);
|
|
kfree(info);
|
|
return r;
|
|
}
|
|
|
|
r = 0;
|
|
#ifdef CONFIG_HVC_XEN_FRONTEND
|
|
r = xenbus_register_frontend(&xencons_driver);
|
|
#endif
|
|
return r;
|
|
}
|
|
|
|
static void __exit xen_hvc_fini(void)
|
|
{
|
|
struct xencons_info *entry, *next;
|
|
|
|
if (list_empty(&xenconsoles))
|
|
return;
|
|
|
|
list_for_each_entry_safe(entry, next, &xenconsoles, list) {
|
|
xen_console_remove(entry);
|
|
}
|
|
}
|
|
|
|
static int xen_cons_init(void)
|
|
{
|
|
const struct hv_ops *ops;
|
|
|
|
if (!xen_domain())
|
|
return 0;
|
|
|
|
if (xen_initial_domain())
|
|
ops = &dom0_hvc_ops;
|
|
else {
|
|
int r;
|
|
ops = &domU_hvc_ops;
|
|
|
|
if (xen_hvm_domain())
|
|
r = xen_hvm_console_init();
|
|
else
|
|
r = xen_pv_console_init();
|
|
if (r < 0)
|
|
return r;
|
|
}
|
|
|
|
hvc_instantiate(HVC_COOKIE, 0, ops);
|
|
return 0;
|
|
}
|
|
|
|
|
|
module_init(xen_hvc_init);
|
|
module_exit(xen_hvc_fini);
|
|
console_initcall(xen_cons_init);
|
|
|
|
#ifdef CONFIG_EARLY_PRINTK
|
|
static void xenboot_write_console(struct console *console, const char *string,
|
|
unsigned len)
|
|
{
|
|
unsigned int linelen, off = 0;
|
|
const char *pos;
|
|
|
|
if (!xen_pv_domain())
|
|
return;
|
|
|
|
dom0_write_console(0, string, len);
|
|
|
|
if (xen_initial_domain())
|
|
return;
|
|
|
|
domU_write_console(0, "(early) ", 8);
|
|
while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
|
|
linelen = pos-string+off;
|
|
if (off + linelen > len)
|
|
break;
|
|
domU_write_console(0, string+off, linelen);
|
|
domU_write_console(0, "\r\n", 2);
|
|
off += linelen + 1;
|
|
}
|
|
if (off < len)
|
|
domU_write_console(0, string+off, len-off);
|
|
}
|
|
|
|
struct console xenboot_console = {
|
|
.name = "xenboot",
|
|
.write = xenboot_write_console,
|
|
.flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
|
|
};
|
|
#endif /* CONFIG_EARLY_PRINTK */
|
|
|
|
void xen_raw_console_write(const char *str)
|
|
{
|
|
dom0_write_console(0, str, strlen(str));
|
|
}
|
|
|
|
void xen_raw_printk(const char *fmt, ...)
|
|
{
|
|
static char buf[512];
|
|
va_list ap;
|
|
|
|
va_start(ap, fmt);
|
|
vsnprintf(buf, sizeof(buf), fmt, ap);
|
|
va_end(ap);
|
|
|
|
xen_raw_console_write(buf);
|
|
}
|