trans_virtio.c revision ee443996a35c1e04f210cafd43d5a98d41e46085
1b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen/* 2b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * The Guest 9p transport driver 3b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * 4e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen * This is a block based transport driver based on the lguest block driver 5e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen * code. 6b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * 7b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen */ 8b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen/* 9b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * Copyright (C) 2007 Eric Van Hensbergen, IBM Corporation 10b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * 11b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * Based on virtio console driver 12b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation 13b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * 14b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * This program is free software; you can redistribute it and/or modify 15b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * it under the terms of the GNU General Public License version 2 16b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * as published by the Free Software Foundation. 17b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * 18b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * This program is distributed in the hope that it will be useful, 19b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * but WITHOUT ANY WARRANTY; without even the implied warranty of 20b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * GNU General Public License for more details. 22b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * 23b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * You should have received a copy of the GNU General Public License 24b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * along with this program; if not, write to: 25b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * Free Software Foundation 26b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * 51 Franklin Street, Fifth Floor 27b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * Boston, MA 02111-1301 USA 28b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * 29b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen */ 30b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 31b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/in.h> 32b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/module.h> 33b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/net.h> 34b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/ipv6.h> 35b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/errno.h> 36b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/kernel.h> 37b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/un.h> 38b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/uaccess.h> 39b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/inet.h> 40b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/idr.h> 41b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/file.h> 42b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <net/9p/9p.h> 43b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/parser.h> 44b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <net/9p/transport.h> 45b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/scatterlist.h> 46b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/virtio.h> 47b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#include <linux/virtio_9p.h> 48b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 49e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen#define VIRTQUEUE_NUM 128 50e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 51b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen/* a single mutex to manage channel initialization and attachment */ 52b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergenstatic DECLARE_MUTEX(virtio_9p_lock); 53b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen/* global which tracks highest initialized channel */ 54b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergenstatic int chan_index; 55b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 56e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen#define P9_INIT_MAXTAG 16 57e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 58ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 59ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 60ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * enum p9_req_status_t - virtio request status 61ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @REQ_STATUS_IDLE: request slot unused 62ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @REQ_STATUS_SENT: request sent to server 63ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @REQ_STATUS_RCVD: response received from server 64ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @REQ_STATUS_FLSH: request has been flushed 65ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 66ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * The @REQ_STATUS_IDLE state is used to mark a request slot as unused 67ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * but use is actually tracked by the idpool structure which handles tag 68ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * id allocation. 69ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 70ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen */ 71ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 72ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergenenum p9_req_status_t { 73ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen REQ_STATUS_IDLE, 74ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen REQ_STATUS_SENT, 75ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen REQ_STATUS_RCVD, 76ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen REQ_STATUS_FLSH, 77ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen}; 78ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 79ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 80ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * struct p9_req_t - virtio request slots 81ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @status: status of this request slot 82ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @wq: wait_queue for the client to block on for this request 83ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 84ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * The virtio transport uses an array to track outstanding requests 85ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * instead of a list. While this may incurr overhead during initial 86ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * allocation or expansion, it makes request lookup much easier as the 87ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * tag id is a index into an array. (We use tag+1 so that we can accomodate 88ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * the -1 tag for the T_VERSION request). 89ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * This also has the nice effect of only having to allocate wait_queues 90ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * once, instead of constantly allocating and freeing them. Its possible 91ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * other resources could benefit from this scheme as well. 92ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 93ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen */ 94e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 95e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergenstruct p9_req_t { 96e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int status; 97e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen wait_queue_head_t *wq; 98e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen}; 99e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 100ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 101ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * struct virtio_chan - per-instance transport information 102ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @initialized: whether the channel is initialized 103ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @inuse: whether the channel is in use 104ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @lock: protects multiple elements within this structure 105ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @vdev: virtio dev associated with this channel 106ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @vq: virtio queue associated with this channel 107ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @tagpool: accounting for tag ids (and request slots) 108ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @reqs: array of request slots 109ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @max_tag: current number of request_slots allocated 110ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @sg: scatter gather list which is used to pack a request (protected?) 111ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 112ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * We keep all per-channel information in a structure. 113b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * This structure is allocated within the devices dev->mem space. 114b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * A pointer to the structure will get put in the transport private. 115ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 116b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen */ 117ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 118b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergenstatic struct virtio_chan { 119ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen bool initialized; 120ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen bool inuse; 121b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 122e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen spinlock_t lock; 123e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 124b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen struct virtio_device *vdev; 125e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen struct virtqueue *vq; 126b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 127e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen struct p9_idpool *tagpool; 128e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen struct p9_req_t *reqs; 129e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int max_tag; 130b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 131e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen /* Scatterlist: can be too big for stack. */ 132e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen struct scatterlist sg[VIRTQUEUE_NUM]; 133b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen} channels[MAX_9P_CHAN]; 134b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 135ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 136ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * p9_lookup_tag - Lookup requests by tag 137ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @c: virtio channel to lookup tag within 138ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @tag: numeric id for transaction 139ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 140ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * this is a simple array lookup, but will grow the 141ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * request_slots as necessary to accomodate transaction 142ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * ids which did not previously have a slot. 143ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 144ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * Bugs: there is currently no upper limit on request slots set 145ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * here, but that should be constrained by the id accounting. 146ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen */ 147ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 148e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergenstatic struct p9_req_t *p9_lookup_tag(struct virtio_chan *c, u16 tag) 149e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen{ 150e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen /* This looks up the original request by tag so we know which 151e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen * buffer to read the data into */ 152e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen tag++; 153e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 154e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen while (tag >= c->max_tag) { 155e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int old_max = c->max_tag; 156e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int count; 157e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 158e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (c->max_tag) 159e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen c->max_tag *= 2; 160e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen else 161e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen c->max_tag = P9_INIT_MAXTAG; 162e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 163e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen c->reqs = krealloc(c->reqs, sizeof(struct p9_req_t)*c->max_tag, 164e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen GFP_ATOMIC); 165e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (!c->reqs) { 166e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen printk(KERN_ERR "Couldn't grow tag array\n"); 167e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen BUG(); 168e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 169e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen for (count = old_max; count < c->max_tag; count++) { 170e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen c->reqs[count].status = REQ_STATUS_IDLE; 17115e29b8b0542f28fc0feed2d60e0377b39a45c4fAdrian Bunk c->reqs[count].wq = kmalloc(sizeof(wait_queue_head_t), 172e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen GFP_ATOMIC); 173e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (!c->reqs[count].wq) { 174e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen printk(KERN_ERR "Couldn't grow tag array\n"); 175e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen BUG(); 176e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 177e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen init_waitqueue_head(c->reqs[count].wq); 178e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 179e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 180e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 181e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen return &c->reqs[tag]; 182e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen} 183e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 184e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 185b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen/* How many bytes left in this page. */ 186b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergenstatic unsigned int rest_of_page(void *data) 187b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen{ 188b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen return PAGE_SIZE - ((unsigned long)data % PAGE_SIZE); 189b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen} 190b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 191ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 192ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * p9_virtio_close - reclaim resources of a channel 193ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @trans: transport state 194ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 195ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * This reclaims a channel by freeing its resources and 196ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * reseting its inuse flag. 197ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 198ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen */ 199ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 200e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergenstatic void p9_virtio_close(struct p9_trans *trans) 201e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen{ 202e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen struct virtio_chan *chan = trans->priv; 203e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int count; 204e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen unsigned int flags; 205b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 206e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen spin_lock_irqsave(&chan->lock, flags); 207e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen p9_idpool_destroy(chan->tagpool); 208e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen for (count = 0; count < chan->max_tag; count++) 209e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen kfree(chan->reqs[count].wq); 210e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen kfree(chan->reqs); 211e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen chan->max_tag = 0; 212e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen spin_unlock_irqrestore(&chan->lock, flags); 213b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 214e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen down(&virtio_9p_lock); 215e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen chan->inuse = false; 216e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen up(&virtio_9p_lock); 217b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 218e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen kfree(trans); 219b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen} 220b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 221ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 222ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * req_done - callback which signals activity from the server 223ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @vq: virtio queue activity was received on 224ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 225ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * This notifies us that the server has triggered some activity 226ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * on the virtio channel - most likely a response to request we 227ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * sent. Figure out which requests now have responses and wake up 228ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * those threads. 229ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 230ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * Bugs: could do with some additional sanity checking, but appears to work. 231ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 232ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen */ 233ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 234e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergenstatic void req_done(struct virtqueue *vq) 235b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen{ 236e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen struct virtio_chan *chan = vq->vdev->priv; 237e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen struct p9_fcall *rc; 238e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen unsigned int len; 239e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen unsigned long flags; 240e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen struct p9_req_t *req; 241e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 242e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen spin_lock_irqsave(&chan->lock, flags); 243e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen while ((rc = chan->vq->vq_ops->get_buf(chan->vq, &len)) != NULL) { 244e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen req = p9_lookup_tag(chan, rc->tag); 245e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen req->status = REQ_STATUS_RCVD; 246e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen wake_up(req->wq); 247e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 248e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen /* In case queue is stopped waiting for more buffers. */ 249e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen spin_unlock_irqrestore(&chan->lock, flags); 250e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen} 251b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 252ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 253ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * pack_sg_list - pack a scatter gather list from a linear buffer 254ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @sg: scatter/gather list to pack into 255ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @start: which segment of the sg_list to start at 256ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @limit: maximum segment to pack data to 257ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @data: data to pack into scatter/gather list 258ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @count: amount of data to pack into the scatter/gather list 259ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 260ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * sg_lists have multiple segments of various sizes. This will pack 261ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * arbitrary data into an existing scatter gather list, segmenting the 262ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * data as necessary within constraints. 263ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 264ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen */ 265ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 266e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergenstatic int 267e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergenpack_sg_list(struct scatterlist *sg, int start, int limit, char *data, 268e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int count) 269e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen{ 270e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int s; 271e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int index = start; 272e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 273e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen while (count) { 274e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen s = rest_of_page(data); 275e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (s > count) 276e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen s = count; 277e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen sg_set_buf(&sg[index++], data, s); 278e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen count -= s; 279e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen data += s; 280d6584f3a08055688b2344eb26379fb2f3147ce91Julia Lawall BUG_ON(index > limit); 281e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 282b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 283e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen return index-start; 284b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen} 285b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 286ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 287ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * p9_virtio_rpc - issue a request and wait for a response 288ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @t: transport state 289ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @tc: &p9_fcall request to transmit 290ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @rc: &p9_fcall to put reponse into 291ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 292ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen */ 293ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 294e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergenstatic int 2958a0dc95fd976a052e5e799ef33e6c8e3141b5dffEric Van Hensbergenp9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc) 296b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen{ 297e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int in, out; 298e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int n, err, size; 299e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen struct virtio_chan *chan = t->priv; 300e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen char *rdata; 301e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen struct p9_req_t *req; 302e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen unsigned long flags; 303e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 304e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (*rc == NULL) { 3058a0dc95fd976a052e5e799ef33e6c8e3141b5dffEric Van Hensbergen *rc = kmalloc(sizeof(struct p9_fcall) + t->msize, GFP_KERNEL); 306e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (!*rc) 307e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen return -ENOMEM; 308e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 309b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 310e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen rdata = (char *)*rc+sizeof(struct p9_fcall); 311b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 312e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen n = P9_NOTAG; 313e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (tc->id != P9_TVERSION) { 314e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen n = p9_idpool_get(chan->tagpool); 315e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (n < 0) 316e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen return -ENOMEM; 317b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen } 318b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 3197c7d90f2dda6daec5a6aaf8f97aacc10ee4deb77Eric Van Hensbergen spin_lock_irqsave(&chan->lock, flags); 320e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen req = p9_lookup_tag(chan, n); 321e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen spin_unlock_irqrestore(&chan->lock, flags); 322b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 323e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen p9_set_tag(tc, n); 324b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 325e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio rpc tag %d\n", n); 326b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 327e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, tc->sdata, tc->size); 3288a0dc95fd976a052e5e799ef33e6c8e3141b5dffEric Van Hensbergen in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata, t->msize); 329b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 330e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen req->status = REQ_STATUS_SENT; 331b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 332e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, tc)) { 333e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen P9_DPRINTK(P9_DEBUG_TRANS, 334e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen "9p debug: virtio rpc add_buf returned failure"); 335e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen return -EIO; 336e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 337b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 338e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen chan->vq->vq_ops->kick(chan->vq); 339b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 340e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen wait_event(*req->wq, req->status == REQ_STATUS_RCVD); 341b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 342e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen size = le32_to_cpu(*(__le32 *) rdata); 343b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 3448a0dc95fd976a052e5e799ef33e6c8e3141b5dffEric Van Hensbergen err = p9_deserialize_fcall(rdata, size, *rc, t->extended); 345e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (err < 0) { 346e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen P9_DPRINTK(P9_DEBUG_TRANS, 347e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen "9p debug: virtio rpc deserialize returned %d\n", err); 348e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen return err; 349e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 350b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 351e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen#ifdef CONFIG_NET_9P_DEBUG 352e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) { 353e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen char buf[150]; 354b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 3558a0dc95fd976a052e5e799ef33e6c8e3141b5dffEric Van Hensbergen p9_printfcall(buf, sizeof(buf), *rc, t->extended); 356e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen printk(KERN_NOTICE ">>> %p %s\n", t, buf); 357e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 358e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen#endif 359b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 360e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (n != P9_NOTAG && p9_idpool_check(n, chan->tagpool)) 361e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen p9_idpool_put(n, chan->tagpool); 362b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 363e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen req->status = REQ_STATUS_IDLE; 364b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 365e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen return 0; 366b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen} 367b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 368ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 369ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * p9_virtio_probe - probe for existence of 9P virtio channels 370ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @vdev: virtio device to probe 371ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 372ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * This probes for existing virtio channels. At present only 373ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * a single channel is in use, so in the future more work may need 374ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * to be done here. 375ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 376ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen */ 377ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 378e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergenstatic int p9_virtio_probe(struct virtio_device *vdev) 379b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen{ 380b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen int err; 381b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen struct virtio_chan *chan; 382b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen int index; 383b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 384b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen down(&virtio_9p_lock); 385b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen index = chan_index++; 386b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen chan = &channels[index]; 387b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen up(&virtio_9p_lock); 388b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 389b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen if (chan_index > MAX_9P_CHAN) { 390b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen printk(KERN_ERR "9p: virtio: Maximum channels exceeded\n"); 391b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen BUG(); 392b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen err = -ENOMEM; 393b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen goto fail; 394b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen } 395b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 396e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen chan->vdev = vdev; 397b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 398e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen /* We expect one virtqueue, for requests. */ 399e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen chan->vq = vdev->config->find_vq(vdev, 0, req_done); 400e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (IS_ERR(chan->vq)) { 401e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen err = PTR_ERR(chan->vq); 402e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen goto out_free_vq; 403b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen } 404e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen chan->vq->vdev->priv = chan; 405e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen spin_lock_init(&chan->lock); 406b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 407e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen sg_init_table(chan->sg, VIRTQUEUE_NUM); 408b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 409b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen chan->inuse = false; 410b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen chan->initialized = true; 411b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen return 0; 412b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 413e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergenout_free_vq: 414e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen vdev->config->del_vq(chan->vq); 415b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergenfail: 416b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen down(&virtio_9p_lock); 417b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen chan_index--; 418b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen up(&virtio_9p_lock); 419b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen return err; 420b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen} 421b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 422ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 423ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 424ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * p9_virtio_create - allocate a new virtio channel 425ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @devname: string identifying the channel to connect to (unused) 426ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @args: args passed from sys_mount() for per-transport options (unused) 427ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @msize: requested maximum packet size 428ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @extended: 9p2000.u enabled flag 429ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 430ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * This sets up a transport channel for 9p communication. Right now 431b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * we only match the first available channel, but eventually we couldlook up 432b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * alternate channels by matching devname versus a virtio_config entry. 433b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen * We use a simple reference count mechanism to ensure that only a single 434ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * mount has a channel open at a time. 435ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 436ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * Bugs: doesn't allow identification of a specific channel 437ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * to allocate, channels are allocated sequentially. This was 438ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * a pragmatic decision to get things rolling, but ideally some 439ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * way of identifying the channel to attach to would be nice 440ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * if we are going to support multiple channels. 441ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 442ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen */ 443ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 4448a0dc95fd976a052e5e799ef33e6c8e3141b5dffEric Van Hensbergenstatic struct p9_trans * 4458a0dc95fd976a052e5e799ef33e6c8e3141b5dffEric Van Hensbergenp9_virtio_create(const char *devname, char *args, int msize, 4468a0dc95fd976a052e5e799ef33e6c8e3141b5dffEric Van Hensbergen unsigned char extended) 447b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen{ 448b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen struct p9_trans *trans; 449b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen struct virtio_chan *chan = channels; 450e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen int index = 0; 451b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 452b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen down(&virtio_9p_lock); 453b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen while (index < MAX_9P_CHAN) { 454b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen if (chan->initialized && !chan->inuse) { 455b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen chan->inuse = true; 456b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen break; 457b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen } else { 458b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen index++; 459b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen chan = &channels[index]; 460b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen } 461b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen } 462b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen up(&virtio_9p_lock); 463b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 464b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen if (index >= MAX_9P_CHAN) { 465e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen printk(KERN_ERR "9p: no channels available\n"); 466e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen return ERR_PTR(-ENODEV); 467e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen } 468e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen 469e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen chan->tagpool = p9_idpool_create(); 470e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen if (IS_ERR(chan->tagpool)) { 471e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen printk(KERN_ERR "9p: couldn't allocate tagpool\n"); 472e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen return ERR_PTR(-ENOMEM); 473b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen } 474e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen p9_idpool_get(chan->tagpool); /* reserve tag 0 */ 475e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen chan->max_tag = 0; 476e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen chan->reqs = NULL; 477b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 478b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL); 479b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen if (!trans) { 480b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen printk(KERN_ERR "9p: couldn't allocate transport\n"); 481b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen return ERR_PTR(-ENOMEM); 482b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen } 4838a0dc95fd976a052e5e799ef33e6c8e3141b5dffEric Van Hensbergen trans->extended = extended; 4848a0dc95fd976a052e5e799ef33e6c8e3141b5dffEric Van Hensbergen trans->msize = msize; 485b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen trans->close = p9_virtio_close; 486e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen trans->rpc = p9_virtio_rpc; 487b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen trans->priv = chan; 488b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 489b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen return trans; 490b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen} 491b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 492ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen/** 493ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * p9_virtio_remove - clean up resources associated with a virtio device 494ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * @vdev: virtio device to remove 495ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen * 496ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen */ 497ee443996a35c1e04f210cafd43d5a98d41e46085Eric Van Hensbergen 498f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergenstatic void p9_virtio_remove(struct virtio_device *vdev) 499f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen{ 500f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen struct virtio_chan *chan = vdev->priv; 501f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen 502f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen BUG_ON(chan->inuse); 503f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen 504f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen if (chan->initialized) { 505f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen vdev->config->del_vq(chan->vq); 506f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen chan->initialized = false; 507f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen } 508f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen} 509f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen 510b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen#define VIRTIO_ID_9P 9 511b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 512b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergenstatic struct virtio_device_id id_table[] = { 513b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen { VIRTIO_ID_9P, VIRTIO_DEV_ANY_ID }, 514b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen { 0 }, 515b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen}; 516b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 517b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen/* The standard "struct lguest_driver": */ 518b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergenstatic struct virtio_driver p9_virtio_drv = { 519b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen .driver.name = KBUILD_MODNAME, 520b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen .driver.owner = THIS_MODULE, 521b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen .id_table = id_table, 522b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen .probe = p9_virtio_probe, 523f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen .remove = p9_virtio_remove, 524b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen}; 525b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 526b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergenstatic struct p9_trans_module p9_virtio_trans = { 527b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen .name = "virtio", 528b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen .create = p9_virtio_create, 529e2735b7720320b68590ca2b32b78ca91213931b2Eric Van Hensbergen .maxsize = PAGE_SIZE*16, 530b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen .def = 0, 531b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen}; 532b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 533b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen/* The standard init function */ 534b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergenstatic int __init p9_virtio_init(void) 535b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen{ 536b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen int count; 537b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 538b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen for (count = 0; count < MAX_9P_CHAN; count++) 539b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen channels[count].initialized = false; 540b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 541b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen v9fs_register_trans(&p9_virtio_trans); 542b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen return register_virtio_driver(&p9_virtio_drv); 543b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen} 544b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 545f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergenstatic void __exit p9_virtio_cleanup(void) 546f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen{ 547f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen unregister_virtio_driver(&p9_virtio_drv); 548f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen} 549f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergen 550b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergenmodule_init(p9_virtio_init); 551f39335453fe79f4e12e263e7c6387dc9fb86bfffEric Van Hensbergenmodule_exit(p9_virtio_cleanup); 552b530cc794024be227876a089e66fb17b7b512763Eric Van Hensbergen 553b530cc794024be227876a089e66fb17b7b512763Eric Van HensbergenMODULE_DEVICE_TABLE(virtio, id_table); 554b530cc794024be227876a089e66fb17b7b512763Eric Van HensbergenMODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>"); 555b530cc794024be227876a089e66fb17b7b512763Eric Van HensbergenMODULE_DESCRIPTION("Virtio 9p Transport"); 556b530cc794024be227876a089e66fb17b7b512763Eric Van HensbergenMODULE_LICENSE("GPL"); 557