--- /dev/null
+/*
+ * 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;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff