Rusty Russell | 3f8c4d3 | 2007-07-19 01:49:27 -0700 | [diff] [blame] | 1 | /* Simple console for lguest. |
| 2 | * |
| 3 | * Copyright (C) 2006 Rusty Russell, IBM Corporation |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 | */ |
| 19 | #include <linux/err.h> |
| 20 | #include <linux/init.h> |
| 21 | #include <linux/lguest_bus.h> |
| 22 | #include "hvc_console.h" |
| 23 | |
| 24 | static char inbuf[256]; |
| 25 | static struct lguest_dma cons_input = { .used_len = 0, |
| 26 | .addr[0] = __pa(inbuf), |
| 27 | .len[0] = sizeof(inbuf), |
| 28 | .len[1] = 0 }; |
| 29 | |
| 30 | static int put_chars(u32 vtermno, const char *buf, int count) |
| 31 | { |
| 32 | struct lguest_dma dma; |
| 33 | |
| 34 | /* FIXME: what if it's over a page boundary? */ |
| 35 | dma.len[0] = count; |
| 36 | dma.len[1] = 0; |
| 37 | dma.addr[0] = __pa(buf); |
| 38 | |
| 39 | lguest_send_dma(LGUEST_CONSOLE_DMA_KEY, &dma); |
| 40 | return count; |
| 41 | } |
| 42 | |
| 43 | static int get_chars(u32 vtermno, char *buf, int count) |
| 44 | { |
| 45 | static int cons_offset; |
| 46 | |
| 47 | if (!cons_input.used_len) |
| 48 | return 0; |
| 49 | |
| 50 | if (cons_input.used_len - cons_offset < count) |
| 51 | count = cons_input.used_len - cons_offset; |
| 52 | |
| 53 | memcpy(buf, inbuf + cons_offset, count); |
| 54 | cons_offset += count; |
| 55 | if (cons_offset == cons_input.used_len) { |
| 56 | cons_offset = 0; |
| 57 | cons_input.used_len = 0; |
| 58 | } |
| 59 | return count; |
| 60 | } |
| 61 | |
| 62 | static struct hv_ops lguest_cons = { |
| 63 | .get_chars = get_chars, |
| 64 | .put_chars = put_chars, |
| 65 | }; |
| 66 | |
| 67 | static int __init cons_init(void) |
| 68 | { |
| 69 | if (strcmp(paravirt_ops.name, "lguest") != 0) |
| 70 | return 0; |
| 71 | |
| 72 | return hvc_instantiate(0, 0, &lguest_cons); |
| 73 | } |
| 74 | console_initcall(cons_init); |
| 75 | |
| 76 | static int lguestcons_probe(struct lguest_device *lgdev) |
| 77 | { |
| 78 | int err; |
| 79 | |
| 80 | lgdev->private = hvc_alloc(0, lgdev_irq(lgdev), &lguest_cons, 256); |
| 81 | if (IS_ERR(lgdev->private)) |
| 82 | return PTR_ERR(lgdev->private); |
| 83 | |
| 84 | err = lguest_bind_dma(LGUEST_CONSOLE_DMA_KEY, &cons_input, 1, |
| 85 | lgdev_irq(lgdev)); |
| 86 | if (err) |
| 87 | printk("lguest console: failed to bind buffer.\n"); |
| 88 | return err; |
| 89 | } |
| 90 | |
| 91 | static struct lguest_driver lguestcons_drv = { |
| 92 | .name = "lguestcons", |
| 93 | .owner = THIS_MODULE, |
| 94 | .device_type = LGUEST_DEVICE_T_CONSOLE, |
| 95 | .probe = lguestcons_probe, |
| 96 | }; |
| 97 | |
| 98 | static int __init hvc_lguest_init(void) |
| 99 | { |
| 100 | return register_lguest_driver(&lguestcons_drv); |
| 101 | } |
| 102 | module_init(hvc_lguest_init); |