160 lines
3.8 KiB
C
160 lines
3.8 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 <asm/xen/hypervisor.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 "hvc_console.h"
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#define HVC_COOKIE 0x58656e /* "Xen" in hex */
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static struct hvc_struct *hvc;
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static int xencons_irq;
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/* ------------------------------------------------------------------ */
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static inline struct xencons_interface *xencons_interface(void)
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{
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return mfn_to_virt(xen_start_info->console.domU.mfn);
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}
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static inline void notify_daemon(void)
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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(xen_start_info->console.domU.evtchn);
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}
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static int write_console(uint32_t vtermno, const char *data, int len)
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{
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struct xencons_interface *intf = xencons_interface();
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XENCONS_RING_IDX cons, prod;
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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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notify_daemon();
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return sent;
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}
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static int read_console(uint32_t vtermno, char *buf, int len)
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{
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struct xencons_interface *intf = xencons_interface();
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XENCONS_RING_IDX cons, prod;
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int recv = 0;
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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();
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return recv;
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}
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static struct hv_ops hvc_ops = {
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.get_chars = read_console,
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.put_chars = write_console,
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};
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static int __init xen_init(void)
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{
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struct hvc_struct *hp;
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if (!is_running_on_xen())
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return 0;
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xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
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if (xencons_irq < 0)
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xencons_irq = 0 /* NO_IRQ */;
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hp = hvc_alloc(HVC_COOKIE, xencons_irq, &hvc_ops, 256);
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if (IS_ERR(hp))
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return PTR_ERR(hp);
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hvc = hp;
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return 0;
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}
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static void __exit xen_fini(void)
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{
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if (hvc)
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hvc_remove(hvc);
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}
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static int xen_cons_init(void)
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{
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if (!is_running_on_xen())
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return 0;
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hvc_instantiate(HVC_COOKIE, 0, &hvc_ops);
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return 0;
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}
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module_init(xen_init);
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module_exit(xen_fini);
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console_initcall(xen_cons_init);
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static void xenboot_write_console(struct console *console, const char *string,
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unsigned len)
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{
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unsigned int linelen, off = 0;
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const char *pos;
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while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
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linelen = pos-string+off;
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if (off + linelen > len)
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break;
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write_console(0, string+off, linelen);
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write_console(0, "\r\n", 2);
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off += linelen + 1;
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}
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if (off < len)
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write_console(0, string+off, len-off);
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}
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struct console xenboot_console = {
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.name = "xenboot",
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.write = xenboot_write_console,
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.flags = CON_PRINTBUFFER | CON_BOOT,
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};
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