diff options
| -rw-r--r-- | drivers/scsi/scsi_tgt_if.c | 350 | ||||
| -rw-r--r-- | include/scsi/scsi_tgt_if.h | 90 |
2 files changed, 440 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_tgt_if.c b/drivers/scsi/scsi_tgt_if.c new file mode 100644 index 0000000..28fd222 --- /dev/null +++ b/drivers/scsi/scsi_tgt_if.c @@ -0,0 +1,350 @@ +/* + * 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 "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; +} diff --git a/include/scsi/scsi_tgt_if.h b/include/scsi/scsi_tgt_if.h new file mode 100644 index 0000000..46d5e70 --- /dev/null +++ b/include/scsi/scsi_tgt_if.h @@ -0,0 +1,90 @@ +/* + * SCSI target kernel/user interface + * + * 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 + */ +#ifndef __SCSI_TARGET_IF_H +#define __SCSI_TARGET_IF_H + +/* user -> kernel */ +#define TGT_UEVENT_CMD_RSP 0x0001 +#define TGT_UEVENT_TSK_MGMT_RSP 0x0002 + +/* kernel -> user */ +#define TGT_KEVENT_CMD_REQ 0x1001 +#define TGT_KEVENT_CMD_DONE 0x1002 +#define TGT_KEVENT_TSK_MGMT_REQ 0x1003 + +struct tgt_event_hdr { + uint16_t version; + uint16_t status; + uint16_t type; + uint16_t len; +} __attribute__ ((aligned (sizeof(uint64_t)))); + +struct tgt_event { + struct tgt_event_hdr hdr; + + union { + /* user-> kernel */ + struct { + int host_no; + uint32_t len; + int result; + aligned_u64 uaddr; + uint8_t rw; + aligned_u64 tag; + } cmd_rsp; + struct { + int host_no; + aligned_u64 mid; + int result; + } tsk_mgmt_rsp; + + + /* kernel -> user */ + struct { + int host_no; + uint32_t data_len; + uint8_t scb[16]; + uint8_t lun[8]; + int attribute; + aligned_u64 tag; + } cmd_req; + struct { + int host_no; + aligned_u64 tag; + int result; + } cmd_done; + struct { + int host_no; + int function; + aligned_u64 tag; + uint8_t lun[8]; + aligned_u64 mid; + } tsk_mgmt_req; + } p; +} __attribute__ ((aligned (sizeof(uint64_t)))); + +#define TGT_RING_SIZE (1UL << 16) +#define TGT_RING_PAGES (TGT_RING_SIZE >> PAGE_SHIFT) +#define TGT_EVENT_PER_PAGE (PAGE_SIZE / sizeof(struct tgt_event)) +#define TGT_MAX_EVENTS (TGT_EVENT_PER_PAGE * TGT_RING_PAGES) + +#endif |
