path: root/drivers/block/sunvdc.c

/* sunvdc.c: Sun LDOM Virtual Disk Client.
 *
 * Copyright (C) 2007 David S. Miller <davem@davemloft.net>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/scatterlist.h>

#include <asm/vio.h>
#include <asm/ldc.h>

#define DRV_MODULE_NAME		"sunvdc"
#define PFX DRV_MODULE_NAME	": "
#define DRV_MODULE_VERSION	"1.0"
#define DRV_MODULE_RELDATE	"June 25, 2007"

static char version[] __devinitdata =
	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
MODULE_DESCRIPTION("Sun LDOM virtual disk client driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_MODULE_VERSION);

#define VDC_TX_RING_SIZE	256

#define WAITING_FOR_LINK_UP	0x01
#define WAITING_FOR_TX_SPACE	0x02
#define WAITING_FOR_GEN_CMD	0x04
#define WAITING_FOR_ANY		-1

struct vdc_req_entry {
	struct request		*req;
};

struct vdc_port {
	struct vio_driver_state	vio;

	struct gendisk		*disk;

	struct vdc_completion	*cmp;

	u64			req_id;
	u64			seq;
	struct vdc_req_entry	rq_arr[VDC_TX_RING_SIZE];

	unsigned long		ring_cookies;

	u64			max_xfer_size;
	u32			vdisk_block_size;

	/* The server fills these in for us in the disk attribute
	 * ACK packet.
	 */
	u64			operations;
	u32			vdisk_size;
	u8			vdisk_type;

	char			disk_name[32];

	struct vio_disk_geom	geom;
	struct vio_disk_vtoc	label;
};

static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
{
	return container_of(vio, struct vdc_port, vio);
}

/* Ordered from largest major to lowest */
static struct vio_version vdc_versions[] = {
	{ .major = 1, .minor = 0 },
};

#define VDCBLK_NAME	"vdisk"
static int vdc_major;
#define PARTITION_SHIFT	3

static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
{
	return vio_dring_avail(dr, VDC_TX_RING_SIZE);
}

static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct gendisk *disk = bdev->bd_disk;
	struct vdc_port *port = disk->private_data;

	geo->heads = (u8) port->geom.num_hd;
	geo->sectors = (u8) port->geom.num_sec;
	geo->cylinders = port->geom.num_cyl;

	return 0;
}

static struct block_device_operations vdc_fops = {
	.owner		= THIS_MODULE,
	.getgeo		= vdc_getgeo,
};

static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
{
	if (vio->cmp &&
	    (waiting_for == -1 ||
	     vio->cmp->waiting_for == waiting_for)) {
		vio->cmp->err = err;
		complete(&vio->cmp->com);
		vio->cmp = NULL;
	}
}

static void vdc_handshake_complete(struct vio_driver_state *vio)
{
	vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
}

static int vdc_handle_unknown(struct vdc_port *port, void *arg)
{
	struct vio_msg_tag *pkt = arg;

	printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
	       pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
	printk(KERN_ERR PFX "Resetting connection.\n");

	ldc_disconnect(port->vio.lp);

	return -ECONNRESET;
}

static int vdc_send_attr(struct vio_driver_state *vio)
{
	struct vdc_port *port = to_vdc_port(vio);
	struct vio_disk_attr_info pkt;

	memset(&pkt, 0, sizeof(pkt));

	pkt.tag.type = VIO_TYPE_CTRL;
	pkt.tag.stype = VIO_SUBTYPE_INFO;
	pkt.tag.stype_env = VIO_ATTR_INFO;
	pkt.tag.sid = vio_send_sid(vio);

	pkt.xfer_mode = VIO_DRING_MODE;
	pkt.vdisk_block_size = port->vdisk_block_size;
	pkt.max_xfer_size = port->max_xfer_size;

	viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%lu]\n",
	       pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);

	return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
}

static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
{
	struct vdc_port *port = to_vdc_port(vio);
	struct vio_disk_attr_info *pkt = arg;

	viodbg(HS, "GOT ATTR stype[0x%x] ops[%lx] disk_size[%lu] disk_type[%x] "
	       "xfer_mode[0x%x] blksz[%u] max_xfer[%lu]\n",
	       pkt->tag.stype, pkt->operations,
	       pkt->vdisk_size, pkt->vdisk_type,
	       pkt->xfer_mode, pkt->vdisk_block_size,
	       pkt->max_xfer_size);

	if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
		switch (pkt->vdisk_type) {
		case VD_DISK_TYPE_DISK:
		case VD_DISK_TYPE_SLICE:
			break;

		default: