1 files changed, 352 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_tgt_if.c b/drivers/scsi/scsi_tgt_if.c
new file mode 100644
index 000000000000..37bbfbdb870f
--- /dev/null
+++ b/drivers/scsi/scsi_tgt_if.c
@@ -0,0 +1,352 @@
+/*
+ * SCSI target kernel/user interface functions
+ *
+ * Copyright (C) 2005 FUJITA Tomonori <tomof@acm.org>
+ * Copyright (C) 2005 Mike Christie <michaelc@cs.wisc.edu>
+ *
+ * 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) any 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+#include <linux/miscdevice.h>
+#include <linux/file.h>
+#include <net/tcp.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_tgt.h>
+#include <scsi/scsi_tgt_if.h>
+
+#include <asm/cacheflush.h>
+
+#include "scsi_tgt_priv.h"
+
+struct tgt_ring {
+	u32 tr_idx;
+	unsigned long tr_pages[TGT_RING_PAGES];
+	spinlock_t tr_lock;
+};
+
+/* tx_ring : kernel->user, rx_ring : user->kernel */
+static struct tgt_ring tx_ring, rx_ring;
+static DECLARE_WAIT_QUEUE_HEAD(tgt_poll_wait);
+
+static inline void tgt_ring_idx_inc(struct tgt_ring *ring)
+{
+	if (ring->tr_idx == TGT_MAX_EVENTS - 1)
+		ring->tr_idx = 0;
+	else
+		ring->tr_idx++;
+}
+
+static struct tgt_event *tgt_head_event(struct tgt_ring *ring, u32 idx)
+{
+	u32 pidx, off;
+
+	pidx = idx / TGT_EVENT_PER_PAGE;
+	off = idx % TGT_EVENT_PER_PAGE;
+
+	return (struct tgt_event *)
+		(ring->tr_pages[pidx] + sizeof(struct tgt_event) * off);
+}
+
+static int tgt_uspace_send_event(u32 type, struct tgt_event *p)
+{
+	struct tgt_event *ev;
+	struct tgt_ring *ring = &tx_ring;
+	unsigned long flags;
+	int err = 0;
+
+	spin_lock_irqsave(&ring->tr_lock, flags);
+
+	ev = tgt_head_event(ring, ring->tr_idx);
+	if (!ev->hdr.status)
+		tgt_ring_idx_inc(ring);
+	else
+		err = -BUSY;
+
+	spin_unlock_irqrestore(&ring->tr_lock, flags);
+
+	if (err)
+		return err;
+
+	memcpy(ev, p, sizeof(*ev));
+	ev->hdr.type = type;
+	mb();
+	ev->hdr.status = 1;
+
+	flush_dcache_page(virt_to_page(ev));
+
+	wake_up_interruptible(&tgt_poll_wait);
+
+	return 0;
+}
+
+int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, struct scsi_lun *lun, u64 tag)
+{
+	struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
+	struct tgt_event ev;
+	int err;
+
+	memset(&ev, 0, sizeof(ev));
+	ev.p.cmd_req.host_no = shost->host_no;
+	ev.p.cmd_req.data_len = cmd->request_bufflen;
+	memcpy(ev.p.cmd_req.scb, cmd->cmnd, sizeof(ev.p.cmd_req.scb));
+	memcpy(ev.p.cmd_req.lun, lun, sizeof(ev.p.cmd_req.lun));
+	ev.p.cmd_req.attribute = cmd->tag;
+	ev.p.cmd_req.tag = tag;
+
+	dprintk("%p %d %u %x %llx\n", cmd, shost->host_no,
+		ev.p.cmd_req.data_len, cmd->tag,
+		(unsigned long long) ev.p.cmd_req.tag);
+
+	err = tgt_uspace_send_event(TGT_KEVENT_CMD_REQ, &ev);
+	if (err)
+		eprintk("tx buf is full, could not send\n");
+
+	return err;
+}
+
+int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 tag)
+{
+	struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
+	struct tgt_event ev;
+	int err;
+
+	memset(&ev, 0, sizeof(ev));
+	ev.p.cmd_done.host_no = shost->host_no;
+	ev.p.cmd_done.tag = tag;
+	ev.p.cmd_done.result = cmd->result;
+
+	dprintk("%p %d %llu %u %x\n", cmd, shost->host_no,
+		(unsigned long long) ev.p.cmd_req.tag,
+		ev.p.cmd_req.data_len, cmd->tag);
+
+	err = tgt_uspace_send_event(TGT_KEVENT_CMD_DONE, &ev);
+	if (err)
+		eprintk("tx buf is full, could not send\n");
+
+	return err;
+}
+
+int scsi_tgt_uspace_send_tsk_mgmt(int host_no, int function, u64 tag,
+				  struct scsi_lun *scsilun, void *data)
+{
+	struct tgt_event ev;
+	int err;
+
+	memset(&ev, 0, sizeof(ev));
+	ev.p.tsk_mgmt_req.host_no = host_no;
+	ev.p.tsk_mgmt_req.function = function;
+	ev.p.tsk_mgmt_req.tag = tag;
+	memcpy(ev.p.tsk_mgmt_req.lun, scsilun, sizeof(ev.p.tsk_mgmt_req.lun));
+	ev.p.tsk_mgmt_req.mid = (u64) (unsigned long) data;
+
+	dprintk("%d %x %llx %llx\n", host_no, function, (unsigned long long) tag,
+		(unsigned long long) ev.p.tsk_mgmt_req.mid);
+
+	err = tgt_uspace_send_event(TGT_KEVENT_TSK_MGMT_REQ, &ev);
+	if (err)
+		eprintk("tx buf is full, could not send\n");
+
+	return err;
+}
+
+static int event_recv_msg(struct tgt_event *ev)
+{
+	int err = 0;
+
+	switch (ev->hdr.type) {
+	case TGT_UEVENT_CMD_RSP:
+		err = scsi_tgt_kspace_exec(ev->p.cmd_rsp.host_no,
+					   ev->p.cmd_rsp.tag,
+					   ev->p.cmd_rsp.result,
+					   ev->p.cmd_rsp.len,
+					   ev->p.cmd_rsp.uaddr,
+					   ev->p.cmd_rsp.rw);
+		break;
+	case TGT_UEVENT_TSK_MGMT_RSP:
+		err = scsi_tgt_kspace_tsk_mgmt(ev->p.tsk_mgmt_rsp.host_no,
+					       ev->p.tsk_mgmt_rsp.mid,
+					       ev->p.tsk_mgmt_rsp.result);
+		break;
+	default:
+		eprintk("unknown type %d\n", ev->hdr.type);
+		err = -EINVAL;
+	}
+
+	return err;
+}
+
+static ssize_t tgt_write(struct file *file, const char __user * buffer,
+			 size_t count, loff_t * ppos)
+{
+	struct tgt_event *ev;
+	struct tgt_ring *ring = &rx_ring;
+
+	while (1) {
+		ev = tgt_head_event(ring, ring->tr_idx);
+		/* do we need this? */
+		flush_dcache_page(virt_to_page(ev));
+
+		if (!ev->hdr.status)
+			break;
+
+		tgt_ring_idx_inc(ring);
+		event_recv_msg(ev);
+		ev->hdr.status = 0;
+	};
+
+	return count;
+}
+
+static unsigned int tgt_poll(struct file * file, struct poll_table_struct *wait)
+{
+	struct tgt_event *ev;
+	struct tgt_ring *ring = &tx_ring;
+	unsigned long flags;
+	unsigned int mask = 0;
+	u32 idx;
+
+	poll_wait(file, &tgt_poll_wait, wait);
+
+	spin_lock_irqsave(&ring->tr_lock, flags);
+
+	idx = ring->tr_idx ? ring->tr_idx - 1 : TGT_MAX_EVENTS - 1;
+	ev = tgt_head_event(ring, idx);
+	if (ev->hdr.status)
+		mask |= POLLIN | POLLRDNORM;
+
+	spin_unlock_irqrestore(&ring->tr_lock, flags);
+
+	return mask;
+}
+
+static int uspace_ring_map(struct vm_area_struct *vma, unsigned long addr,
+			   struct tgt_ring *ring)
+{
+	int i, err;
+
+	for (i = 0; i < TGT_RING_PAGES; i++) {
+		struct page *page = virt_to_page(ring->tr_pages[i]);
+		err = vm_insert_page(vma, addr, page);
+		if (err)
+			return err;
+		addr += PAGE_SIZE;
+	}
+
+	return 0;
+}
+
+static int tgt_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	unsigned long addr;
+	int err;
+
+	if (vma->vm_pgoff)
+		return -EINVAL;
+
+	if (vma->vm_end - vma->vm_start != TGT_RING_SIZE * 2) {
+		eprintk("mmap size must be %lu, not %lu \n",
+			TGT_RING_SIZE * 2, vma->vm_end - vma->vm_start);
+		return -EINVAL;
+	}
+
+	addr = vma->vm_start;
+	err = uspace_ring_map(vma, addr, &tx_ring);
+	if (err)
+		return err;
+	err = uspace_ring_map(vma, addr + TGT_RING_SIZE, &rx_ring);
+
+	return err;
+}
+
+static int tgt_open(struct inode *inode, struct file *file)
+{
+	tx_ring.tr_idx = rx_ring.tr_idx = 0;
+
+	return 0;
+}
+
+static struct file_operations tgt_fops = {
+	.owner		= THIS_MODULE,
+	.open		= tgt_open,
+	.poll		= tgt_poll,
+	.write		= tgt_write,
+	.mmap		= tgt_mmap,
+};
+
+static struct miscdevice tgt_miscdev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "tgt",
+	.fops = &tgt_fops,
+};
+
+static void tgt_ring_exit(struct tgt_ring *ring)
+{
+	int i;
+
+	for (i = 0; i < TGT_RING_PAGES; i++)
+		free_page(ring->tr_pages[i]);
+}
+
+static int tgt_ring_init(struct tgt_ring *ring)
+{
+	int i;
+
+	spin_lock_init(&ring->tr_lock);
+
+	for (i = 0; i < TGT_RING_PAGES; i++) {
+		ring->tr_pages[i] = get_zeroed_page(GFP_KERNEL);
+		if (!ring->tr_pages[i]) {
+			eprintk("out of memory\n");
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+void scsi_tgt_if_exit(void)
+{
+	tgt_ring_exit(&tx_ring);
+	tgt_ring_exit(&rx_ring);
+	misc_deregister(&tgt_miscdev);
+}
+
+int scsi_tgt_if_init(void)
+{
+	int err;
+
+	err = tgt_ring_init(&tx_ring);
+	if (err)
+		return err;
+
+	err = tgt_ring_init(&rx_ring);
+	if (err)
+		goto free_tx_ring;
+
+	err = misc_register(&tgt_miscdev);
+	if (err)
+		goto free_rx_ring;
+
+	return 0;
+free_rx_ring:
+	tgt_ring_exit(&rx_ring);
+free_tx_ring:
+	tgt_ring_exit(&tx_ring);
+
+	return err;
+}