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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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398 lines
9.1 KiB
C
398 lines
9.1 KiB
C
/*
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* SCSI target kernel/user interface functions
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*
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* Copyright (C) 2005 FUJITA Tomonori <tomof@acm.org>
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* Copyright (C) 2005 Mike Christie <michaelc@cs.wisc.edu>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*/
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#include <linux/miscdevice.h>
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#include <linux/file.h>
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#include <linux/smp_lock.h>
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#include <net/tcp.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_cmnd.h>
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#include <scsi/scsi_device.h>
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#include <scsi/scsi_host.h>
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#include <scsi/scsi_tgt.h>
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#include <scsi/scsi_tgt_if.h>
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#include <asm/cacheflush.h>
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#include "scsi_tgt_priv.h"
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#if TGT_RING_SIZE < PAGE_SIZE
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# define TGT_RING_SIZE PAGE_SIZE
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#endif
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#define TGT_RING_PAGES (TGT_RING_SIZE >> PAGE_SHIFT)
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#define TGT_EVENT_PER_PAGE (PAGE_SIZE / sizeof(struct tgt_event))
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#define TGT_MAX_EVENTS (TGT_EVENT_PER_PAGE * TGT_RING_PAGES)
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struct tgt_ring {
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u32 tr_idx;
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unsigned long tr_pages[TGT_RING_PAGES];
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spinlock_t tr_lock;
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};
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/* tx_ring : kernel->user, rx_ring : user->kernel */
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static struct tgt_ring tx_ring, rx_ring;
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static DECLARE_WAIT_QUEUE_HEAD(tgt_poll_wait);
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static inline void tgt_ring_idx_inc(struct tgt_ring *ring)
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{
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if (ring->tr_idx == TGT_MAX_EVENTS - 1)
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ring->tr_idx = 0;
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else
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ring->tr_idx++;
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}
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static struct tgt_event *tgt_head_event(struct tgt_ring *ring, u32 idx)
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{
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u32 pidx, off;
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pidx = idx / TGT_EVENT_PER_PAGE;
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off = idx % TGT_EVENT_PER_PAGE;
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return (struct tgt_event *)
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(ring->tr_pages[pidx] + sizeof(struct tgt_event) * off);
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}
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static int tgt_uspace_send_event(u32 type, struct tgt_event *p)
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{
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struct tgt_event *ev;
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struct tgt_ring *ring = &tx_ring;
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unsigned long flags;
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int err = 0;
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spin_lock_irqsave(&ring->tr_lock, flags);
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ev = tgt_head_event(ring, ring->tr_idx);
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if (!ev->hdr.status)
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tgt_ring_idx_inc(ring);
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else
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err = -BUSY;
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spin_unlock_irqrestore(&ring->tr_lock, flags);
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if (err)
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return err;
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memcpy(ev, p, sizeof(*ev));
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ev->hdr.type = type;
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mb();
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ev->hdr.status = 1;
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flush_dcache_page(virt_to_page(ev));
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wake_up_interruptible(&tgt_poll_wait);
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return 0;
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}
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int scsi_tgt_uspace_send_cmd(struct scsi_cmnd *cmd, u64 itn_id,
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struct scsi_lun *lun, u64 tag)
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{
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struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
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struct tgt_event ev;
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int err;
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memset(&ev, 0, sizeof(ev));
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ev.p.cmd_req.host_no = shost->host_no;
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ev.p.cmd_req.itn_id = itn_id;
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ev.p.cmd_req.data_len = scsi_bufflen(cmd);
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memcpy(ev.p.cmd_req.scb, cmd->cmnd, sizeof(ev.p.cmd_req.scb));
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memcpy(ev.p.cmd_req.lun, lun, sizeof(ev.p.cmd_req.lun));
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ev.p.cmd_req.attribute = cmd->tag;
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ev.p.cmd_req.tag = tag;
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dprintk("%p %d %u %x %llx\n", cmd, shost->host_no,
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ev.p.cmd_req.data_len, cmd->tag,
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(unsigned long long) ev.p.cmd_req.tag);
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err = tgt_uspace_send_event(TGT_KEVENT_CMD_REQ, &ev);
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if (err)
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eprintk("tx buf is full, could not send\n");
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return err;
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}
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int scsi_tgt_uspace_send_status(struct scsi_cmnd *cmd, u64 itn_id, u64 tag)
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{
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struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
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struct tgt_event ev;
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int err;
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memset(&ev, 0, sizeof(ev));
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ev.p.cmd_done.host_no = shost->host_no;
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ev.p.cmd_done.itn_id = itn_id;
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ev.p.cmd_done.tag = tag;
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ev.p.cmd_done.result = cmd->result;
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dprintk("%p %d %llu %u %x\n", cmd, shost->host_no,
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(unsigned long long) ev.p.cmd_req.tag,
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ev.p.cmd_req.data_len, cmd->tag);
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err = tgt_uspace_send_event(TGT_KEVENT_CMD_DONE, &ev);
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if (err)
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eprintk("tx buf is full, could not send\n");
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return err;
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}
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int scsi_tgt_uspace_send_tsk_mgmt(int host_no, u64 itn_id, int function,
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u64 tag, struct scsi_lun *scsilun, void *data)
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{
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struct tgt_event ev;
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int err;
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memset(&ev, 0, sizeof(ev));
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ev.p.tsk_mgmt_req.host_no = host_no;
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ev.p.tsk_mgmt_req.itn_id = itn_id;
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ev.p.tsk_mgmt_req.function = function;
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ev.p.tsk_mgmt_req.tag = tag;
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memcpy(ev.p.tsk_mgmt_req.lun, scsilun, sizeof(ev.p.tsk_mgmt_req.lun));
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ev.p.tsk_mgmt_req.mid = (u64) (unsigned long) data;
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dprintk("%d %x %llx %llx\n", host_no, function, (unsigned long long) tag,
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(unsigned long long) ev.p.tsk_mgmt_req.mid);
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err = tgt_uspace_send_event(TGT_KEVENT_TSK_MGMT_REQ, &ev);
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if (err)
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eprintk("tx buf is full, could not send\n");
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return err;
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}
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int scsi_tgt_uspace_send_it_nexus_request(int host_no, u64 itn_id,
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int function, char *initiator_id)
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{
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struct tgt_event ev;
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int err;
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memset(&ev, 0, sizeof(ev));
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ev.p.it_nexus_req.host_no = host_no;
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ev.p.it_nexus_req.function = function;
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ev.p.it_nexus_req.itn_id = itn_id;
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if (initiator_id)
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strncpy(ev.p.it_nexus_req.initiator_id, initiator_id,
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sizeof(ev.p.it_nexus_req.initiator_id));
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dprintk("%d %x %llx\n", host_no, function, (unsigned long long)itn_id);
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err = tgt_uspace_send_event(TGT_KEVENT_IT_NEXUS_REQ, &ev);
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if (err)
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eprintk("tx buf is full, could not send\n");
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return err;
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}
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static int event_recv_msg(struct tgt_event *ev)
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{
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int err = 0;
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switch (ev->hdr.type) {
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case TGT_UEVENT_CMD_RSP:
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err = scsi_tgt_kspace_exec(ev->p.cmd_rsp.host_no,
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ev->p.cmd_rsp.itn_id,
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ev->p.cmd_rsp.result,
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ev->p.cmd_rsp.tag,
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ev->p.cmd_rsp.uaddr,
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ev->p.cmd_rsp.len,
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ev->p.cmd_rsp.sense_uaddr,
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ev->p.cmd_rsp.sense_len,
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ev->p.cmd_rsp.rw);
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break;
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case TGT_UEVENT_TSK_MGMT_RSP:
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err = scsi_tgt_kspace_tsk_mgmt(ev->p.tsk_mgmt_rsp.host_no,
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ev->p.tsk_mgmt_rsp.itn_id,
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ev->p.tsk_mgmt_rsp.mid,
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ev->p.tsk_mgmt_rsp.result);
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break;
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case TGT_UEVENT_IT_NEXUS_RSP:
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err = scsi_tgt_kspace_it_nexus_rsp(ev->p.it_nexus_rsp.host_no,
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ev->p.it_nexus_rsp.itn_id,
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ev->p.it_nexus_rsp.result);
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break;
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default:
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eprintk("unknown type %d\n", ev->hdr.type);
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err = -EINVAL;
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}
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return err;
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}
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static ssize_t tgt_write(struct file *file, const char __user * buffer,
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size_t count, loff_t * ppos)
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{
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struct tgt_event *ev;
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struct tgt_ring *ring = &rx_ring;
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while (1) {
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ev = tgt_head_event(ring, ring->tr_idx);
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/* do we need this? */
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flush_dcache_page(virt_to_page(ev));
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if (!ev->hdr.status)
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break;
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tgt_ring_idx_inc(ring);
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event_recv_msg(ev);
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ev->hdr.status = 0;
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};
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return count;
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}
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static unsigned int tgt_poll(struct file * file, struct poll_table_struct *wait)
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{
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struct tgt_event *ev;
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struct tgt_ring *ring = &tx_ring;
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unsigned long flags;
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unsigned int mask = 0;
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u32 idx;
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poll_wait(file, &tgt_poll_wait, wait);
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spin_lock_irqsave(&ring->tr_lock, flags);
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idx = ring->tr_idx ? ring->tr_idx - 1 : TGT_MAX_EVENTS - 1;
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ev = tgt_head_event(ring, idx);
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if (ev->hdr.status)
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mask |= POLLIN | POLLRDNORM;
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spin_unlock_irqrestore(&ring->tr_lock, flags);
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return mask;
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}
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static int uspace_ring_map(struct vm_area_struct *vma, unsigned long addr,
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struct tgt_ring *ring)
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{
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int i, err;
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for (i = 0; i < TGT_RING_PAGES; i++) {
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struct page *page = virt_to_page(ring->tr_pages[i]);
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err = vm_insert_page(vma, addr, page);
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if (err)
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return err;
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addr += PAGE_SIZE;
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}
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return 0;
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}
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static int tgt_mmap(struct file *filp, struct vm_area_struct *vma)
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{
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unsigned long addr;
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int err;
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if (vma->vm_pgoff)
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return -EINVAL;
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if (vma->vm_end - vma->vm_start != TGT_RING_SIZE * 2) {
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eprintk("mmap size must be %lu, not %lu \n",
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TGT_RING_SIZE * 2, vma->vm_end - vma->vm_start);
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return -EINVAL;
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}
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addr = vma->vm_start;
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err = uspace_ring_map(vma, addr, &tx_ring);
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if (err)
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return err;
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err = uspace_ring_map(vma, addr + TGT_RING_SIZE, &rx_ring);
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return err;
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}
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static int tgt_open(struct inode *inode, struct file *file)
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{
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tx_ring.tr_idx = rx_ring.tr_idx = 0;
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cycle_kernel_lock();
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return 0;
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}
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static const struct file_operations tgt_fops = {
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.owner = THIS_MODULE,
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.open = tgt_open,
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.poll = tgt_poll,
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.write = tgt_write,
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.mmap = tgt_mmap,
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};
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static struct miscdevice tgt_miscdev = {
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.minor = MISC_DYNAMIC_MINOR,
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.name = "tgt",
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.fops = &tgt_fops,
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};
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static void tgt_ring_exit(struct tgt_ring *ring)
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{
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int i;
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for (i = 0; i < TGT_RING_PAGES; i++)
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free_page(ring->tr_pages[i]);
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}
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static int tgt_ring_init(struct tgt_ring *ring)
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{
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int i;
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spin_lock_init(&ring->tr_lock);
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for (i = 0; i < TGT_RING_PAGES; i++) {
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ring->tr_pages[i] = get_zeroed_page(GFP_KERNEL);
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if (!ring->tr_pages[i]) {
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eprintk("out of memory\n");
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return -ENOMEM;
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}
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}
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return 0;
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}
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void scsi_tgt_if_exit(void)
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{
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tgt_ring_exit(&tx_ring);
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tgt_ring_exit(&rx_ring);
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misc_deregister(&tgt_miscdev);
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}
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int scsi_tgt_if_init(void)
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{
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int err;
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err = tgt_ring_init(&tx_ring);
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if (err)
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return err;
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err = tgt_ring_init(&rx_ring);
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if (err)
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goto free_tx_ring;
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err = misc_register(&tgt_miscdev);
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if (err)
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goto free_rx_ring;
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return 0;
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free_rx_ring:
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tgt_ring_exit(&rx_ring);
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free_tx_ring:
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tgt_ring_exit(&tx_ring);
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return err;
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}
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