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[/] [test_project/] [trunk/] [linux_sd_driver/] [drivers/] [char/] [hvc_xen.c] - Blame information for rev 62

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Line No. Rev Author Line
1 62 marcus.erl
/*
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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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