viocd.c

linux 内核源代码

/* -*- linux-c -*-
 *  drivers/cdrom/viocd.c
 *
 *  iSeries Virtual CD Rom
 *
 *  Authors: Dave Boutcher <[e-mail]>
 *           Ryan Arnold <[e-mail]>
 *           Colin Devilbiss <[e-mail]>
 *           Stephen Rothwell <[e-mail]>
 *
 * (C) Copyright 2000-2004 IBM Corporation
 *
 * This program is free software;  you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) anyu later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * This routine provides access to CD ROM drives owned and managed by an
 * OS/400 partition running on the same box as this Linux partition.
 *
 * All operations are performed by sending messages back and forth to
 * the OS/400 partition.
 */

#include <linux/major.h>
#include <linux/blkdev.h>
#include <linux/cdrom.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/completion.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/scatterlist.h>

#include <asm/vio.h>
#include <asm/iseries/hv_types.h>
#include <asm/iseries/hv_lp_event.h>
#include <asm/iseries/vio.h>
#include <asm/firmware.h>

#define VIOCD_DEVICE			"iseries/vcd"

#define VIOCD_VERS "1.06"

#define VIOCD_KERN_WARNING		KERN_WARNING "viocd: "
#define VIOCD_KERN_INFO			KERN_INFO "viocd: "

/*
 * Should probably make this a module parameter....sigh
 */
#define VIOCD_MAX_CD	HVMAXARCHITECTEDVIRTUALCDROMS

static const struct vio_error_entry viocd_err_table[] = {
	{0x0201, EINVAL, "Invalid Range"},
	{0x0202, EINVAL, "Invalid Token"},
	{0x0203, EIO, "DMA Error"},
	{0x0204, EIO, "Use Error"},
	{0x0205, EIO, "Release Error"},
	{0x0206, EINVAL, "Invalid CD"},
	{0x020C, EROFS, "Read Only Device"},
	{0x020D, ENOMEDIUM, "Changed or Missing Volume (or Varied Off?)"},
	{0x020E, EIO, "Optical System Error (Varied Off?)"},
	{0x02FF, EIO, "Internal Error"},
	{0x3010, EIO, "Changed Volume"},
	{0xC100, EIO, "Optical System Error"},
	{0x0000, 0, NULL},
};

/*
 * This is the structure we use to exchange info between driver and interrupt
 * handler
 */
struct viocd_waitevent {
	struct completion	com;
	int			rc;
	u16			sub_result;
	int			changed;
};

/* this is a lookup table for the true capabilities of a device */
struct capability_entry {
	char	*type;
	int	capability;
};

static struct capability_entry capability_table[] __initdata = {
	{ "6330", CDC_LOCK | CDC_DVD_RAM | CDC_RAM },
	{ "6331", CDC_LOCK | CDC_DVD_RAM | CDC_RAM },
	{ "6333", CDC_LOCK | CDC_DVD_RAM | CDC_RAM },
	{ "632A", CDC_LOCK | CDC_DVD_RAM | CDC_RAM },
	{ "6321", CDC_LOCK },
	{ "632B", 0 },
	{ NULL  , CDC_LOCK },
};

/* These are our internal structures for keeping track of devices */
static int viocd_numdev;

struct disk_info {
	struct gendisk			*viocd_disk;
	struct cdrom_device_info	viocd_info;
	struct device			*dev;
	const char			*rsrcname;
	const char			*type;
	const char			*model;
};
static struct disk_info viocd_diskinfo[VIOCD_MAX_CD];

#define DEVICE_NR(di)	((di) - &viocd_diskinfo[0])

static spinlock_t viocd_reqlock;

#define MAX_CD_REQ	1

/* procfs support */
static int proc_viocd_show(struct seq_file *m, void *v)
{
	int i;

	for (i = 0; i < viocd_numdev; i++) {
		seq_printf(m, "viocd device %d is iSeries resource %10.10s"
				"type %4.4s, model %3.3s\n",
				i, viocd_diskinfo[i].rsrcname,
				viocd_diskinfo[i].type,
				viocd_diskinfo[i].model);
	}
	return 0;
}

static int proc_viocd_open(struct inode *inode, struct file *file)
{
	return single_open(file, proc_viocd_show, NULL);
}

static const struct file_operations proc_viocd_operations = {
	.open		= proc_viocd_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int viocd_blk_open(struct inode *inode, struct file *file)
{
	struct disk_info *di = inode->i_bdev->bd_disk->private_data;
	return cdrom_open(&di->viocd_info, inode, file);
}

static int viocd_blk_release(struct inode *inode, struct file *file)
{
	struct disk_info *di = inode->i_bdev->bd_disk->private_data;
	return cdrom_release(&di->viocd_info, file);
}

static int viocd_blk_ioctl(struct inode *inode, struct file *file,
		unsigned cmd, unsigned long arg)
{
	struct disk_info *di = inode->i_bdev->bd_disk->private_data;
	return cdrom_ioctl(file, &di->viocd_info, inode, cmd, arg);
}

static int viocd_blk_media_changed(struct gendisk *disk)
{
	struct disk_info *di = disk->private_data;
	return cdrom_media_changed(&di->viocd_info);
}

struct block_device_operations viocd_fops = {
	.owner =		THIS_MODULE,
	.open =			viocd_blk_open,
	.release =		viocd_blk_release,
	.ioctl =		viocd_blk_ioctl,
	.media_changed =	viocd_blk_media_changed,
};

static int viocd_open(struct cdrom_device_info *cdi, int purpose)
{
        struct disk_info *diskinfo = cdi->handle;
	int device_no = DEVICE_NR(diskinfo);
	HvLpEvent_Rc hvrc;
	struct viocd_waitevent we;

	init_completion(&we.com);
	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
			HvLpEvent_Type_VirtualIo,
			viomajorsubtype_cdio | viocdopen,
			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
			viopath_sourceinst(viopath_hostLp),
			viopath_targetinst(viopath_hostLp),
			(u64)&we, VIOVERSION << 16, ((u64)device_no << 48),
			0, 0, 0);
	if (hvrc != 0) {
		printk(VIOCD_KERN_WARNING
				"bad rc on HvCallEvent_signalLpEventFast %d\n",
				(int)hvrc);
		return -EIO;
	}

	wait_for_completion(&we.com);

	if (we.rc) {
		const struct vio_error_entry *err =
			vio_lookup_rc(viocd_err_table, we.sub_result);
		printk(VIOCD_KERN_WARNING "bad rc %d:0x%04X on open: %s\n",
				we.rc, we.sub_result, err->msg);
		return -err->errno;
	}

	return 0;
}

static void viocd_release(struct cdrom_device_info *cdi)
{
	int device_no = DEVICE_NR((struct disk_info *)cdi->handle);
	HvLpEvent_Rc hvrc;

	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
			HvLpEvent_Type_VirtualIo,
			viomajorsubtype_cdio | viocdclose,
			HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
			viopath_sourceinst(viopath_hostLp),
			viopath_targetinst(viopath_hostLp), 0,
			VIOVERSION << 16, ((u64)device_no << 48), 0, 0, 0);
	if (hvrc != 0)
		printk(VIOCD_KERN_WARNING
				"bad rc on HvCallEvent_signalLpEventFast %d\n",
				(int)hvrc);
}

/* Send a read or write request to OS/400 */
static int send_request(struct request *req)
{
	HvLpEvent_Rc hvrc;
	struct disk_info *diskinfo = req->rq_disk->private_data;
	u64 len;
	dma_addr_t dmaaddr;
	int direction;
	u16 cmd;
	struct scatterlist sg;

	BUG_ON(req->nr_phys_segments > 1);

	if (rq_data_dir(req) == READ) {
		direction = DMA_FROM_DEVICE;
		cmd = viomajorsubtype_cdio | viocdread;
	} else {
		direction = DMA_TO_DEVICE;
		cmd = viomajorsubtype_cdio | viocdwrite;
	}

	sg_init_table(&sg, 1);
        if (blk_rq_map_sg(req->q, req, &sg) == 0) {
		printk(VIOCD_KERN_WARNING
				"error setting up scatter/gather list\n");
		return -1;
	}

	if (dma_map_sg(diskinfo->dev, &sg, 1, direction) == 0) {
		printk(VIOCD_KERN_WARNING "error allocating sg tce\n");
		return -1;
	}
	dmaaddr = sg_dma_address(&sg);
	len = sg_dma_len(&sg);

	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
			HvLpEvent_Type_VirtualIo, cmd,
			HvLpEvent_AckInd_DoAck,
			HvLpEvent_AckType_ImmediateAck,
			viopath_sourceinst(viopath_hostLp),
			viopath_targetinst(viopath_hostLp),
			(u64)req, VIOVERSION << 16,
			((u64)DEVICE_NR(diskinfo) << 48) | dmaaddr,
			(u64)req->sector * 512, len, 0);
	if (hvrc != HvLpEvent_Rc_Good) {
		printk(VIOCD_KERN_WARNING "hv error on op %d\n", (int)hvrc);
		return -1;
	}

	return 0;
}

static void viocd_end_request(struct request *req, int uptodate)
{
	int nsectors = req->hard_nr_sectors;

	/*
	 * Make sure it's fully ended, and ensure that we process
	 * at least one sector.
	 */
	if (blk_pc_request(req))
		nsectors = (req->data_len + 511) >> 9;
	if (!nsectors)
		nsectors = 1;

	if (end_that_request_first(req, uptodate, nsectors))
		BUG();
	add_disk_randomness(req->rq_disk);
	blkdev_dequeue_request(req);
	end_that_request_last(req, uptodate);
}

static int rwreq;

static void do_viocd_request(struct request_queue *q)
{
	struct request *req;

	while ((rwreq == 0) && ((req = elv_next_request(q)) != NULL)) {
		if (!blk_fs_request(req))
			viocd_end_request(req, 0);
		else if (send_request(req) < 0) {
			printk(VIOCD_KERN_WARNING
					"unable to send message to OS/400!");
			viocd_end_request(req, 0);
		} else
			rwreq++;
	}
}

static int viocd_media_changed(struct cdrom_device_info *cdi, int disc_nr)
{
	struct viocd_waitevent we;
	HvLpEvent_Rc hvrc;
	int device_no = DEVICE_NR((struct disk_info *)cdi->handle);

	init_completion(&we.com);

	/* Send the open event to OS/400 */
	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
			HvLpEvent_Type_VirtualIo,
			viomajorsubtype_cdio | viocdcheck,
			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
			viopath_sourceinst(viopath_hostLp),
			viopath_targetinst(viopath_hostLp),
			(u64)&we, VIOVERSION << 16, ((u64)device_no << 48),
			0, 0, 0);
	if (hvrc != 0) {
		printk(VIOCD_KERN_WARNING "bad rc on HvCallEvent_signalLpEventFast %d\n",
				(int)hvrc);
		return -EIO;
	}

	wait_for_completion(&we.com);

	/* Check the return code.  If bad, assume no change */
	if (we.rc) {
		const struct vio_error_entry *err =
			vio_lookup_rc(viocd_err_table, we.sub_result);
		printk(VIOCD_KERN_WARNING
				"bad rc %d:0x%04X on check_change: %s; Assuming no change\n",
				we.rc, we.sub_result, err->msg);
		return 0;
	}

	return we.changed;
}

static int viocd_lock_door(struct cdrom_device_info *cdi, int locking)
{
	HvLpEvent_Rc hvrc;
	u64 device_no = DEVICE_NR((struct disk_info *)cdi->handle);
	/* NOTE: flags is 1 or 0 so it won't overwrite the device_no */
	u64 flags = !!locking;
	struct viocd_waitevent we;

	init_completion(&we.com);

	/* Send the lockdoor event to OS/400 */