/* * 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 <linux/smp_lock.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" #if TGT_RING_SIZE < PAGE_SIZE # define TGT_RING_SIZE PAGE_SIZE #endif #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) 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, u64 itn_id, 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.itn_id = itn_id; ev.p.cmd_req.data_len = scsi_bufflen(cmd); 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 itn_id, 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.itn_id = itn_id; 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, u64 itn_id, 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.itn_id = itn_id; 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; } int scsi_tgt_uspace_send_it_nexus_request(int host_no, u64 itn_id, int function, char *initiator_id) { struct tgt_event ev; int err; memset(&ev, 0, sizeof(ev)); ev.p.it_nexus_req.host_no = host_no; ev.p.it_nexus_req.function = function; ev.p.it_nexus_req.itn_id = itn_id; if (initiator_id) strncpy(ev.p.it_nexus_req.initiator_id, initiator_id, sizeof(ev.p.it_nexus_req.initiator_id)); dprintk("%d %x %llx\n", host_no, function, (unsigned long long)itn_id); err = tgt_uspace_send_event(TGT_KEVENT_IT_NEXUS_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.itn_id, ev->p.cmd_rsp.result, ev->p.cmd_rsp.tag, ev->p.cmd_rsp.uaddr, ev->p.cmd_rsp.len, ev->p.cmd_rsp.sense_uaddr, ev->p.cmd_rsp.sense_len, 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.itn_id, ev->p.tsk_mgmt_rsp.mid, ev->p.tsk_mgmt_rsp.result); break; case TGT_UEVENT_IT_NEXUS_RSP: err = scsi_tgt_kspace_it_nexus_rsp(ev->p.it_nexus_rsp.host_no, ev->p.it_nexus_rsp.itn_id, ev->p.it_nexus_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; cycle_kernel_lock(); return 0; } static const 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; }