1125 lines
28 KiB
C
1125 lines
28 KiB
C
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/*
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* vhba.c
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*
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* Copyright (C) 2007-2012 Chia-I Wu <olvaffe AT gmail DOT com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (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,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU 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 along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#define pr_fmt(fmt) "vhba: " fmt
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#include <linux/version.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/highmem.h>
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#include <linux/fs.h>
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#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
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#include <linux/sched/signal.h>
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#else
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#include <linux/sched.h>
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#endif
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#include <linux/platform_device.h>
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#include <linux/miscdevice.h>
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#include <linux/poll.h>
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#include <linux/slab.h>
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#include <linux/scatterlist.h>
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#ifdef CONFIG_COMPAT
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#include <linux/compat.h>
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#endif
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#include <asm/uaccess.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_host.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_tcq.h>
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MODULE_AUTHOR("Chia-I Wu");
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MODULE_VERSION(VHBA_VERSION);
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MODULE_DESCRIPTION("Virtual SCSI HBA");
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MODULE_LICENSE("GPL");
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#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 15, 0)
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#define sdev_dbg(sdev, fmt, a...) \
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dev_dbg(&(sdev)->sdev_gendev, fmt, ##a)
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#define scmd_dbg(scmd, fmt, a...) \
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dev_dbg(&(scmd)->device->sdev_gendev, fmt, ##a)
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#endif
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#define VHBA_MAX_SECTORS_PER_IO 256
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#define VHBA_MAX_BUS 16
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#define VHBA_MAX_ID 16
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#define VHBA_MAX_DEVICES (VHBA_MAX_BUS * (VHBA_MAX_ID-1))
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#define VHBA_KBUF_SIZE PAGE_SIZE
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#define DATA_TO_DEVICE(dir) ((dir) == DMA_TO_DEVICE || (dir) == DMA_BIDIRECTIONAL)
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#define DATA_FROM_DEVICE(dir) ((dir) == DMA_FROM_DEVICE || (dir) == DMA_BIDIRECTIONAL)
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static int vhba_can_queue = 32;
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module_param_named(can_queue, vhba_can_queue, int, 0);
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enum vhba_req_state {
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VHBA_REQ_FREE,
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VHBA_REQ_PENDING,
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VHBA_REQ_READING,
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VHBA_REQ_SENT,
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VHBA_REQ_WRITING,
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};
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struct vhba_command {
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struct scsi_cmnd *cmd;
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/* metatags are per-host. not to be confused with
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queue tags that are usually per-lun */
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unsigned long metatag;
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int status;
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struct list_head entry;
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};
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struct vhba_device {
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unsigned int num;
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spinlock_t cmd_lock;
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struct list_head cmd_list;
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wait_queue_head_t cmd_wq;
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atomic_t refcnt;
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unsigned char *kbuf;
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size_t kbuf_size;
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};
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struct vhba_host {
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struct Scsi_Host *shost;
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spinlock_t cmd_lock;
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int cmd_next;
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struct vhba_command *commands;
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spinlock_t dev_lock;
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struct vhba_device *devices[VHBA_MAX_DEVICES];
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int num_devices;
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DECLARE_BITMAP(chgmap, VHBA_MAX_DEVICES);
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int chgtype[VHBA_MAX_DEVICES];
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struct work_struct scan_devices;
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};
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#define MAX_COMMAND_SIZE 16
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struct vhba_request {
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__u32 metatag;
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__u32 lun;
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__u8 cdb[MAX_COMMAND_SIZE];
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__u8 cdb_len;
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__u32 data_len;
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};
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struct vhba_response {
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__u32 metatag;
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__u32 status;
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__u32 data_len;
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};
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struct vhba_command *vhba_alloc_command (void);
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void vhba_free_command (struct vhba_command *vcmd);
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static struct platform_device vhba_platform_device;
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/* These functions define a symmetric 1:1 mapping between device numbers and
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the bus and id. We have reserved the last id per bus for the host itself. */
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void devnum_to_bus_and_id(unsigned int devnum, unsigned int *bus, unsigned int *id)
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{
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*bus = devnum / (VHBA_MAX_ID-1);
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*id = devnum % (VHBA_MAX_ID-1);
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}
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unsigned int bus_and_id_to_devnum(unsigned int bus, unsigned int id)
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{
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return (bus * (VHBA_MAX_ID-1)) + id;
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}
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struct vhba_device *vhba_device_alloc (void)
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{
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struct vhba_device *vdev;
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vdev = kzalloc(sizeof(struct vhba_device), GFP_KERNEL);
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if (!vdev) {
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return NULL;
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}
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spin_lock_init(&vdev->cmd_lock);
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INIT_LIST_HEAD(&vdev->cmd_list);
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init_waitqueue_head(&vdev->cmd_wq);
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atomic_set(&vdev->refcnt, 1);
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vdev->kbuf = NULL;
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vdev->kbuf_size = 0;
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return vdev;
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}
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void vhba_device_put (struct vhba_device *vdev)
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{
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if (atomic_dec_and_test(&vdev->refcnt)) {
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kfree(vdev);
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}
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}
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struct vhba_device *vhba_device_get (struct vhba_device *vdev)
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{
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atomic_inc(&vdev->refcnt);
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return vdev;
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}
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int vhba_device_queue (struct vhba_device *vdev, struct scsi_cmnd *cmd)
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{
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struct vhba_host *vhost;
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struct vhba_command *vcmd;
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unsigned long flags;
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vhost = platform_get_drvdata(&vhba_platform_device);
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vcmd = vhba_alloc_command();
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if (!vcmd) {
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return SCSI_MLQUEUE_HOST_BUSY;
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}
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vcmd->cmd = cmd;
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spin_lock_irqsave(&vdev->cmd_lock, flags);
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#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 15, 0)
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vcmd->metatag = scsi_cmd_to_rq(vcmd->cmd)->tag;
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#else
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vcmd->metatag = vcmd->cmd->request->tag;
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#endif
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list_add_tail(&vcmd->entry, &vdev->cmd_list);
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spin_unlock_irqrestore(&vdev->cmd_lock, flags);
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wake_up_interruptible(&vdev->cmd_wq);
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return 0;
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}
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int vhba_device_dequeue (struct vhba_device *vdev, struct scsi_cmnd *cmd)
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{
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struct vhba_command *vcmd;
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int retval;
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unsigned long flags;
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spin_lock_irqsave(&vdev->cmd_lock, flags);
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list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
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if (vcmd->cmd == cmd) {
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list_del_init(&vcmd->entry);
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break;
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}
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}
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/* command not found */
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if (&vcmd->entry == &vdev->cmd_list) {
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spin_unlock_irqrestore(&vdev->cmd_lock, flags);
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return SUCCESS;
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}
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while (vcmd->status == VHBA_REQ_READING || vcmd->status == VHBA_REQ_WRITING) {
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spin_unlock_irqrestore(&vdev->cmd_lock, flags);
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scmd_dbg(cmd, "wait for I/O before aborting\n");
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schedule_timeout(1);
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spin_lock_irqsave(&vdev->cmd_lock, flags);
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}
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retval = (vcmd->status == VHBA_REQ_SENT) ? FAILED : SUCCESS;
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vhba_free_command(vcmd);
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spin_unlock_irqrestore(&vdev->cmd_lock, flags);
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return retval;
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}
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#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 19, 0)
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int vhba_slave_alloc(struct scsi_device *sdev)
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{
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struct Scsi_Host *shost = sdev->host;
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sdev_dbg(sdev, "enabling tagging (queue depth: %i).\n", sdev->queue_depth);
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#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 17, 0)
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if (!shost_use_blk_mq(shost) && shost->bqt) {
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#else
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if (shost->bqt) {
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#endif
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blk_queue_init_tags(sdev->request_queue, sdev->queue_depth, shost->bqt);
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}
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scsi_adjust_queue_depth(sdev, 0, sdev->queue_depth);
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return 0;
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}
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#endif
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void vhba_scan_devices_add (struct vhba_host *vhost, int bus, int id)
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{
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struct scsi_device *sdev;
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sdev = scsi_device_lookup(vhost->shost, bus, id, 0);
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if (!sdev) {
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scsi_add_device(vhost->shost, bus, id, 0);
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} else {
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dev_warn(&vhost->shost->shost_gendev, "tried to add an already-existing device %d:%d:0!\n", bus, id);
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scsi_device_put(sdev);
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}
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}
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void vhba_scan_devices_remove (struct vhba_host *vhost, int bus, int id)
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{
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struct scsi_device *sdev;
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sdev = scsi_device_lookup(vhost->shost, bus, id, 0);
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if (sdev) {
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scsi_remove_device(sdev);
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scsi_device_put(sdev);
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} else {
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dev_warn(&vhost->shost->shost_gendev, "tried to remove non-existing device %d:%d:0!\n", bus, id);
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}
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}
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void vhba_scan_devices (struct work_struct *work)
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{
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struct vhba_host *vhost = container_of(work, struct vhba_host, scan_devices);
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unsigned long flags;
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int change, exists;
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unsigned int devnum;
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unsigned int bus, id;
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for (;;) {
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spin_lock_irqsave(&vhost->dev_lock, flags);
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devnum = find_first_bit(vhost->chgmap, VHBA_MAX_DEVICES);
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if (devnum >= VHBA_MAX_DEVICES) {
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spin_unlock_irqrestore(&vhost->dev_lock, flags);
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break;
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}
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change = vhost->chgtype[devnum];
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exists = vhost->devices[devnum] != NULL;
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vhost->chgtype[devnum] = 0;
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clear_bit(devnum, vhost->chgmap);
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spin_unlock_irqrestore(&vhost->dev_lock, flags);
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devnum_to_bus_and_id(devnum, &bus, &id);
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if (change < 0) {
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dev_dbg(&vhost->shost->shost_gendev, "trying to remove target %d:%d:0\n", bus, id);
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vhba_scan_devices_remove(vhost, bus, id);
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} else if (change > 0) {
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dev_dbg(&vhost->shost->shost_gendev, "trying to add target %d:%d:0\n", bus, id);
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vhba_scan_devices_add(vhost, bus, id);
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} else {
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/* quick sequence of add/remove or remove/add; we determine
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which one it was by checking if device structure exists */
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if (exists) {
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/* remove followed by add: remove and (re)add */
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dev_dbg(&vhost->shost->shost_gendev, "trying to (re)add target %d:%d:0\n", bus, id);
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vhba_scan_devices_remove(vhost, bus, id);
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vhba_scan_devices_add(vhost, bus, id);
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} else {
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/* add followed by remove: no-op */
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dev_dbg(&vhost->shost->shost_gendev, "no-op for target %d:%d:0\n", bus, id);
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}
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}
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}
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}
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int vhba_add_device (struct vhba_device *vdev)
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{
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struct vhba_host *vhost;
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unsigned int devnum;
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unsigned long flags;
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vhost = platform_get_drvdata(&vhba_platform_device);
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vhba_device_get(vdev);
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spin_lock_irqsave(&vhost->dev_lock, flags);
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if (vhost->num_devices >= VHBA_MAX_DEVICES) {
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spin_unlock_irqrestore(&vhost->dev_lock, flags);
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vhba_device_put(vdev);
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return -EBUSY;
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}
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for (devnum = 0; devnum < VHBA_MAX_DEVICES; devnum++) {
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if (vhost->devices[devnum] == NULL) {
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vdev->num = devnum;
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vhost->devices[devnum] = vdev;
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vhost->num_devices++;
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set_bit(devnum, vhost->chgmap);
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vhost->chgtype[devnum]++;
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break;
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}
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}
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spin_unlock_irqrestore(&vhost->dev_lock, flags);
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schedule_work(&vhost->scan_devices);
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return 0;
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}
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|
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int vhba_remove_device (struct vhba_device *vdev)
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{
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struct vhba_host *vhost;
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unsigned long flags;
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vhost = platform_get_drvdata(&vhba_platform_device);
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spin_lock_irqsave(&vhost->dev_lock, flags);
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set_bit(vdev->num, vhost->chgmap);
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vhost->chgtype[vdev->num]--;
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vhost->devices[vdev->num] = NULL;
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vhost->num_devices--;
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spin_unlock_irqrestore(&vhost->dev_lock, flags);
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vhba_device_put(vdev);
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schedule_work(&vhost->scan_devices);
|
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return 0;
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}
|
||
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|
||
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struct vhba_device *vhba_lookup_device (int devnum)
|
||
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{
|
||
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struct vhba_host *vhost;
|
||
|
struct vhba_device *vdev = NULL;
|
||
|
unsigned long flags;
|
||
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|
||
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vhost = platform_get_drvdata(&vhba_platform_device);
|
||
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|
||
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if (likely(devnum < VHBA_MAX_DEVICES)) {
|
||
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spin_lock_irqsave(&vhost->dev_lock, flags);
|
||
|
vdev = vhost->devices[devnum];
|
||
|
if (vdev) {
|
||
|
vdev = vhba_device_get(vdev);
|
||
|
}
|
||
|
|
||
|
spin_unlock_irqrestore(&vhost->dev_lock, flags);
|
||
|
}
|
||
|
|
||
|
return vdev;
|
||
|
}
|
||
|
|
||
|
struct vhba_command *vhba_alloc_command (void)
|
||
|
{
|
||
|
struct vhba_host *vhost;
|
||
|
struct vhba_command *vcmd;
|
||
|
unsigned long flags;
|
||
|
int i;
|
||
|
|
||
|
vhost = platform_get_drvdata(&vhba_platform_device);
|
||
|
|
||
|
spin_lock_irqsave(&vhost->cmd_lock, flags);
|
||
|
|
||
|
vcmd = vhost->commands + vhost->cmd_next++;
|
||
|
if (vcmd->status != VHBA_REQ_FREE) {
|
||
|
for (i = 0; i < vhba_can_queue; i++) {
|
||
|
vcmd = vhost->commands + i;
|
||
|
|
||
|
if (vcmd->status == VHBA_REQ_FREE) {
|
||
|
vhost->cmd_next = i + 1;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (i == vhba_can_queue) {
|
||
|
vcmd = NULL;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (vcmd) {
|
||
|
vcmd->status = VHBA_REQ_PENDING;
|
||
|
}
|
||
|
|
||
|
vhost->cmd_next %= vhba_can_queue;
|
||
|
|
||
|
spin_unlock_irqrestore(&vhost->cmd_lock, flags);
|
||
|
|
||
|
return vcmd;
|
||
|
}
|
||
|
|
||
|
void vhba_free_command (struct vhba_command *vcmd)
|
||
|
{
|
||
|
struct vhba_host *vhost;
|
||
|
unsigned long flags;
|
||
|
|
||
|
vhost = platform_get_drvdata(&vhba_platform_device);
|
||
|
|
||
|
spin_lock_irqsave(&vhost->cmd_lock, flags);
|
||
|
vcmd->status = VHBA_REQ_FREE;
|
||
|
spin_unlock_irqrestore(&vhost->cmd_lock, flags);
|
||
|
}
|
||
|
|
||
|
int vhba_queuecommand (struct Scsi_Host *shost, struct scsi_cmnd *cmd)
|
||
|
{
|
||
|
struct vhba_device *vdev;
|
||
|
int retval;
|
||
|
unsigned int devnum;
|
||
|
|
||
|
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 15, 0)
|
||
|
scmd_dbg(cmd, "queue %p tag %i\n", cmd, scsi_cmd_to_rq(cmd)->tag);
|
||
|
#else
|
||
|
scmd_dbg(cmd, "queue %p tag %i\n", cmd, cmd->request->tag);
|
||
|
#endif
|
||
|
|
||
|
devnum = bus_and_id_to_devnum(cmd->device->channel, cmd->device->id);
|
||
|
vdev = vhba_lookup_device(devnum);
|
||
|
if (!vdev) {
|
||
|
scmd_dbg(cmd, "no such device\n");
|
||
|
|
||
|
cmd->result = DID_NO_CONNECT << 16;
|
||
|
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
|
||
|
scsi_done(cmd);
|
||
|
#else
|
||
|
cmd->scsi_done(cmd);
|
||
|
#endif
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
retval = vhba_device_queue(vdev, cmd);
|
||
|
|
||
|
vhba_device_put(vdev);
|
||
|
|
||
|
return retval;
|
||
|
}
|
||
|
|
||
|
int vhba_abort (struct scsi_cmnd *cmd)
|
||
|
{
|
||
|
struct vhba_device *vdev;
|
||
|
int retval = SUCCESS;
|
||
|
unsigned int devnum;
|
||
|
|
||
|
scmd_dbg(cmd, "abort %p\n", cmd);
|
||
|
|
||
|
devnum = bus_and_id_to_devnum(cmd->device->channel, cmd->device->id);
|
||
|
vdev = vhba_lookup_device(devnum);
|
||
|
if (vdev) {
|
||
|
retval = vhba_device_dequeue(vdev, cmd);
|
||
|
vhba_device_put(vdev);
|
||
|
} else {
|
||
|
cmd->result = DID_NO_CONNECT << 16;
|
||
|
}
|
||
|
|
||
|
return retval;
|
||
|
}
|
||
|
|
||
|
static struct scsi_host_template vhba_template = {
|
||
|
.module = THIS_MODULE,
|
||
|
.name = "vhba",
|
||
|
.proc_name = "vhba",
|
||
|
.queuecommand = vhba_queuecommand,
|
||
|
.eh_abort_handler = vhba_abort,
|
||
|
.this_id = -1,
|
||
|
.max_sectors = VHBA_MAX_SECTORS_PER_IO,
|
||
|
.sg_tablesize = 256,
|
||
|
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 19, 0)
|
||
|
.slave_alloc = vhba_slave_alloc,
|
||
|
#endif
|
||
|
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 0, 0)
|
||
|
.tag_alloc_policy = BLK_TAG_ALLOC_RR,
|
||
|
#endif
|
||
|
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 19, 0) && LINUX_VERSION_CODE < KERNEL_VERSION(4, 4, 0)
|
||
|
.use_blk_tags = 1,
|
||
|
#endif
|
||
|
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
|
||
|
.max_segment_size = VHBA_KBUF_SIZE,
|
||
|
#endif
|
||
|
};
|
||
|
|
||
|
ssize_t do_request (struct vhba_device *vdev, unsigned long metatag, struct scsi_cmnd *cmd, char __user *buf, size_t buf_len)
|
||
|
{
|
||
|
struct vhba_request vreq;
|
||
|
ssize_t ret;
|
||
|
|
||
|
scmd_dbg(cmd, "request %lu (%p), cdb 0x%x, bufflen %d, sg count %d\n",
|
||
|
metatag, cmd, cmd->cmnd[0], scsi_bufflen(cmd), scsi_sg_count(cmd));
|
||
|
|
||
|
ret = sizeof(vreq);
|
||
|
if (DATA_TO_DEVICE(cmd->sc_data_direction)) {
|
||
|
ret += scsi_bufflen(cmd);
|
||
|
}
|
||
|
|
||
|
if (ret > buf_len) {
|
||
|
scmd_dbg(cmd, "buffer too small (%zd < %zd) for a request\n", buf_len, ret);
|
||
|
return -EIO;
|
||
|
}
|
||
|
|
||
|
vreq.metatag = metatag;
|
||
|
vreq.lun = cmd->device->lun;
|
||
|
memcpy(vreq.cdb, cmd->cmnd, MAX_COMMAND_SIZE);
|
||
|
vreq.cdb_len = cmd->cmd_len;
|
||
|
vreq.data_len = scsi_bufflen(cmd);
|
||
|
|
||
|
if (copy_to_user(buf, &vreq, sizeof(vreq))) {
|
||
|
return -EFAULT;
|
||
|
}
|
||
|
|
||
|
if (DATA_TO_DEVICE(cmd->sc_data_direction) && vreq.data_len) {
|
||
|
buf += sizeof(vreq);
|
||
|
|
||
|
if (scsi_sg_count(cmd)) {
|
||
|
unsigned char *kaddr, *uaddr;
|
||
|
struct scatterlist *sglist = scsi_sglist(cmd);
|
||
|
struct scatterlist *sg;
|
||
|
int i;
|
||
|
|
||
|
uaddr = (unsigned char *) buf;
|
||
|
|
||
|
for_each_sg(sglist, sg, scsi_sg_count(cmd), i) {
|
||
|
size_t len = sg->length;
|
||
|
|
||
|
if (len > vdev->kbuf_size) {
|
||
|
scmd_dbg(cmd, "segment size (%zu) exceeds kbuf size (%zu)!", len, vdev->kbuf_size);
|
||
|
len = vdev->kbuf_size;
|
||
|
}
|
||
|
|
||
|
kaddr = kmap_atomic(sg_page(sg));
|
||
|
memcpy(vdev->kbuf, kaddr + sg->offset, len);
|
||
|
kunmap_atomic(kaddr);
|
||
|
|
||
|
if (copy_to_user(uaddr, vdev->kbuf, len)) {
|
||
|
return -EFAULT;
|
||
|
}
|
||
|
uaddr += len;
|
||
|
}
|
||
|
} else {
|
||
|
if (copy_to_user(buf, scsi_sglist(cmd), vreq.data_len)) {
|
||
|
return -EFAULT;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
ssize_t do_response (struct vhba_device *vdev, unsigned long metatag, struct scsi_cmnd *cmd, const char __user *buf, size_t buf_len, struct vhba_response *res)
|
||
|
{
|
||
|
ssize_t ret = 0;
|
||
|
|
||
|
scmd_dbg(cmd, "response %lu (%p), status %x, data len %d, sg count %d\n",
|
||
|
metatag, cmd, res->status, res->data_len, scsi_sg_count(cmd));
|
||
|
|
||
|
if (res->status) {
|
||
|
if (res->data_len > SCSI_SENSE_BUFFERSIZE) {
|
||
|
scmd_dbg(cmd, "truncate sense (%d < %d)", SCSI_SENSE_BUFFERSIZE, res->data_len);
|
||
|
res->data_len = SCSI_SENSE_BUFFERSIZE;
|
||
|
}
|
||
|
|
||
|
if (copy_from_user(cmd->sense_buffer, buf, res->data_len)) {
|
||
|
return -EFAULT;
|
||
|
}
|
||
|
|
||
|
cmd->result = res->status;
|
||
|
|
||
|
ret += res->data_len;
|
||
|
} else if (DATA_FROM_DEVICE(cmd->sc_data_direction) && scsi_bufflen(cmd)) {
|
||
|
size_t to_read;
|
||
|
|
||
|
if (res->data_len > scsi_bufflen(cmd)) {
|
||
|
scmd_dbg(cmd, "truncate data (%d < %d)\n", scsi_bufflen(cmd), res->data_len);
|
||
|
res->data_len = scsi_bufflen(cmd);
|
||
|
}
|
||
|
|
||
|
to_read = res->data_len;
|
||
|
|
||
|
if (scsi_sg_count(cmd)) {
|
||
|
unsigned char *kaddr, *uaddr;
|
||
|
struct scatterlist *sglist = scsi_sglist(cmd);
|
||
|
struct scatterlist *sg;
|
||
|
int i;
|
||
|
|
||
|
uaddr = (unsigned char *)buf;
|
||
|
|
||
|
for_each_sg(sglist, sg, scsi_sg_count(cmd), i) {
|
||
|
size_t len = (sg->length < to_read) ? sg->length : to_read;
|
||
|
|
||
|
if (len > vdev->kbuf_size) {
|
||
|
scmd_dbg(cmd, "segment size (%zu) exceeds kbuf size (%zu)!", len, vdev->kbuf_size);
|
||
|
len = vdev->kbuf_size;
|
||
|
}
|
||
|
|
||
|
if (copy_from_user(vdev->kbuf, uaddr, len)) {
|
||
|
return -EFAULT;
|
||
|
}
|
||
|
uaddr += len;
|
||
|
|
||
|
kaddr = kmap_atomic(sg_page(sg));
|
||
|
memcpy(kaddr + sg->offset, vdev->kbuf, len);
|
||
|
kunmap_atomic(kaddr);
|
||
|
|
||
|
to_read -= len;
|
||
|
if (to_read == 0) {
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
} else {
|
||
|
if (copy_from_user(scsi_sglist(cmd), buf, res->data_len)) {
|
||
|
return -EFAULT;
|
||
|
}
|
||
|
|
||
|
to_read -= res->data_len;
|
||
|
}
|
||
|
|
||
|
scsi_set_resid(cmd, to_read);
|
||
|
|
||
|
ret += res->data_len - to_read;
|
||
|
}
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
struct vhba_command *next_command (struct vhba_device *vdev)
|
||
|
{
|
||
|
struct vhba_command *vcmd;
|
||
|
|
||
|
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
|
||
|
if (vcmd->status == VHBA_REQ_PENDING) {
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (&vcmd->entry == &vdev->cmd_list) {
|
||
|
vcmd = NULL;
|
||
|
}
|
||
|
|
||
|
return vcmd;
|
||
|
}
|
||
|
|
||
|
struct vhba_command *match_command (struct vhba_device *vdev, __u32 metatag)
|
||
|
{
|
||
|
struct vhba_command *vcmd;
|
||
|
|
||
|
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
|
||
|
if (vcmd->metatag == metatag) {
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (&vcmd->entry == &vdev->cmd_list) {
|
||
|
vcmd = NULL;
|
||
|
}
|
||
|
|
||
|
return vcmd;
|
||
|
}
|
||
|
|
||
|
struct vhba_command *wait_command (struct vhba_device *vdev, unsigned long flags)
|
||
|
{
|
||
|
struct vhba_command *vcmd;
|
||
|
DEFINE_WAIT(wait);
|
||
|
|
||
|
while (!(vcmd = next_command(vdev))) {
|
||
|
if (signal_pending(current)) {
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
prepare_to_wait(&vdev->cmd_wq, &wait, TASK_INTERRUPTIBLE);
|
||
|
|
||
|
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
|
||
|
|
||
|
schedule();
|
||
|
|
||
|
spin_lock_irqsave(&vdev->cmd_lock, flags);
|
||
|
}
|
||
|
|
||
|
finish_wait(&vdev->cmd_wq, &wait);
|
||
|
if (vcmd) {
|
||
|
vcmd->status = VHBA_REQ_READING;
|
||
|
}
|
||
|
|
||
|
return vcmd;
|
||
|
}
|
||
|
|
||
|
ssize_t vhba_ctl_read (struct file *file, char __user *buf, size_t buf_len, loff_t *offset)
|
||
|
{
|
||
|
struct vhba_device *vdev;
|
||
|
struct vhba_command *vcmd;
|
||
|
ssize_t ret;
|
||
|
unsigned long flags;
|
||
|
|
||
|
vdev = file->private_data;
|
||
|
|
||
|
/* Get next command */
|
||
|
if (file->f_flags & O_NONBLOCK) {
|
||
|
/* Non-blocking variant */
|
||
|
spin_lock_irqsave(&vdev->cmd_lock, flags);
|
||
|
vcmd = next_command(vdev);
|
||
|
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
|
||
|
|
||
|
if (!vcmd) {
|
||
|
return -EWOULDBLOCK;
|
||
|
}
|
||
|
} else {
|
||
|
/* Blocking variant */
|
||
|
spin_lock_irqsave(&vdev->cmd_lock, flags);
|
||
|
vcmd = wait_command(vdev, flags);
|
||
|
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
|
||
|
|
||
|
if (!vcmd) {
|
||
|
return -ERESTARTSYS;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
ret = do_request(vdev, vcmd->metatag, vcmd->cmd, buf, buf_len);
|
||
|
|
||
|
spin_lock_irqsave(&vdev->cmd_lock, flags);
|
||
|
if (ret >= 0) {
|
||
|
vcmd->status = VHBA_REQ_SENT;
|
||
|
*offset += ret;
|
||
|
} else {
|
||
|
vcmd->status = VHBA_REQ_PENDING;
|
||
|
}
|
||
|
|
||
|
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
ssize_t vhba_ctl_write (struct file *file, const char __user *buf, size_t buf_len, loff_t *offset)
|
||
|
{
|
||
|
struct vhba_device *vdev;
|
||
|
struct vhba_command *vcmd;
|
||
|
struct vhba_response res;
|
||
|
ssize_t ret;
|
||
|
unsigned long flags;
|
||
|
|
||
|
if (buf_len < sizeof(res)) {
|
||
|
return -EIO;
|
||
|
}
|
||
|
|
||
|
if (copy_from_user(&res, buf, sizeof(res))) {
|
||
|
return -EFAULT;
|
||
|
}
|
||
|
|
||
|
vdev = file->private_data;
|
||
|
|
||
|
spin_lock_irqsave(&vdev->cmd_lock, flags);
|
||
|
vcmd = match_command(vdev, res.metatag);
|
||
|
if (!vcmd || vcmd->status != VHBA_REQ_SENT) {
|
||
|
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
|
||
|
pr_debug("ctl dev #%u not expecting response\n", vdev->num);
|
||
|
return -EIO;
|
||
|
}
|
||
|
vcmd->status = VHBA_REQ_WRITING;
|
||
|
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
|
||
|
|
||
|
ret = do_response(vdev, vcmd->metatag, vcmd->cmd, buf + sizeof(res), buf_len - sizeof(res), &res);
|
||
|
|
||
|
spin_lock_irqsave(&vdev->cmd_lock, flags);
|
||
|
if (ret >= 0) {
|
||
|
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
|
||
|
scsi_done(vcmd->cmd);
|
||
|
#else
|
||
|
vcmd->cmd->scsi_done(vcmd->cmd);
|
||
|
#endif
|
||
|
ret += sizeof(res);
|
||
|
|
||
|
/* don't compete with vhba_device_dequeue */
|
||
|
if (!list_empty(&vcmd->entry)) {
|
||
|
list_del_init(&vcmd->entry);
|
||
|
vhba_free_command(vcmd);
|
||
|
}
|
||
|
} else {
|
||
|
vcmd->status = VHBA_REQ_SENT;
|
||
|
}
|
||
|
|
||
|
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
|
||
|
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
long vhba_ctl_ioctl (struct file *file, unsigned int cmd, unsigned long arg)
|
||
|
{
|
||
|
struct vhba_device *vdev = file->private_data;
|
||
|
struct vhba_host *vhost = platform_get_drvdata(&vhba_platform_device);
|
||
|
|
||
|
switch (cmd) {
|
||
|
case 0xBEEF001: {
|
||
|
unsigned int ident[4]; /* host, channel, id, lun */
|
||
|
|
||
|
ident[0] = vhost->shost->host_no;
|
||
|
devnum_to_bus_and_id(vdev->num, &ident[1], &ident[2]);
|
||
|
ident[3] = 0; /* lun */
|
||
|
|
||
|
if (copy_to_user((void *) arg, ident, sizeof(ident))) {
|
||
|
return -EFAULT;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
case 0xBEEF002: {
|
||
|
unsigned int devnum = vdev->num;
|
||
|
|
||
|
if (copy_to_user((void *) arg, &devnum, sizeof(devnum))) {
|
||
|
return -EFAULT;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return -ENOTTY;
|
||
|
}
|
||
|
|
||
|
#ifdef CONFIG_COMPAT
|
||
|
long vhba_ctl_compat_ioctl (struct file *file, unsigned int cmd, unsigned long arg)
|
||
|
{
|
||
|
unsigned long compat_arg = (unsigned long)compat_ptr(arg);
|
||
|
return vhba_ctl_ioctl(file, cmd, compat_arg);
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
unsigned int vhba_ctl_poll (struct file *file, poll_table *wait)
|
||
|
{
|
||
|
struct vhba_device *vdev = file->private_data;
|
||
|
unsigned int mask = 0;
|
||
|
unsigned long flags;
|
||
|
|
||
|
poll_wait(file, &vdev->cmd_wq, wait);
|
||
|
|
||
|
spin_lock_irqsave(&vdev->cmd_lock, flags);
|
||
|
if (next_command(vdev)) {
|
||
|
mask |= POLLIN | POLLRDNORM;
|
||
|
}
|
||
|
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
|
||
|
|
||
|
return mask;
|
||
|
}
|
||
|
|
||
|
int vhba_ctl_open (struct inode *inode, struct file *file)
|
||
|
{
|
||
|
struct vhba_device *vdev;
|
||
|
int retval;
|
||
|
|
||
|
pr_debug("ctl dev open\n");
|
||
|
|
||
|
/* check if vhba is probed */
|
||
|
if (!platform_get_drvdata(&vhba_platform_device)) {
|
||
|
return -ENODEV;
|
||
|
}
|
||
|
|
||
|
vdev = vhba_device_alloc();
|
||
|
if (!vdev) {
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
|
||
|
vdev->kbuf_size = VHBA_KBUF_SIZE;
|
||
|
vdev->kbuf = kzalloc(vdev->kbuf_size, GFP_KERNEL);
|
||
|
if (!vdev->kbuf) {
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
|
||
|
if (!(retval = vhba_add_device(vdev))) {
|
||
|
file->private_data = vdev;
|
||
|
}
|
||
|
|
||
|
vhba_device_put(vdev);
|
||
|
|
||
|
return retval;
|
||
|
}
|
||
|
|
||
|
int vhba_ctl_release (struct inode *inode, struct file *file)
|
||
|
{
|
||
|
struct vhba_device *vdev;
|
||
|
struct vhba_command *vcmd;
|
||
|
unsigned long flags;
|
||
|
|
||
|
vdev = file->private_data;
|
||
|
|
||
|
pr_debug("ctl dev release\n");
|
||
|
|
||
|
vhba_device_get(vdev);
|
||
|
vhba_remove_device(vdev);
|
||
|
|
||
|
spin_lock_irqsave(&vdev->cmd_lock, flags);
|
||
|
list_for_each_entry(vcmd, &vdev->cmd_list, entry) {
|
||
|
WARN_ON(vcmd->status == VHBA_REQ_READING || vcmd->status == VHBA_REQ_WRITING);
|
||
|
|
||
|
scmd_dbg(vcmd->cmd, "device released with command %lu (%p)\n", vcmd->metatag, vcmd->cmd);
|
||
|
vcmd->cmd->result = DID_NO_CONNECT << 16;
|
||
|
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
|
||
|
scsi_done(vcmd->cmd);
|
||
|
#else
|
||
|
vcmd->cmd->scsi_done(vcmd->cmd);
|
||
|
#endif
|
||
|
vhba_free_command(vcmd);
|
||
|
}
|
||
|
INIT_LIST_HEAD(&vdev->cmd_list);
|
||
|
spin_unlock_irqrestore(&vdev->cmd_lock, flags);
|
||
|
|
||
|
kfree(vdev->kbuf);
|
||
|
vdev->kbuf = NULL;
|
||
|
|
||
|
vhba_device_put(vdev);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static struct file_operations vhba_ctl_fops = {
|
||
|
.owner = THIS_MODULE,
|
||
|
.open = vhba_ctl_open,
|
||
|
.release = vhba_ctl_release,
|
||
|
.read = vhba_ctl_read,
|
||
|
.write = vhba_ctl_write,
|
||
|
.poll = vhba_ctl_poll,
|
||
|
.unlocked_ioctl = vhba_ctl_ioctl,
|
||
|
#ifdef CONFIG_COMPAT
|
||
|
.compat_ioctl = vhba_ctl_compat_ioctl,
|
||
|
#endif
|
||
|
};
|
||
|
|
||
|
static struct miscdevice vhba_miscdev = {
|
||
|
.minor = MISC_DYNAMIC_MINOR,
|
||
|
.name = "vhba_ctl",
|
||
|
.fops = &vhba_ctl_fops,
|
||
|
};
|
||
|
|
||
|
int vhba_probe (struct platform_device *pdev)
|
||
|
{
|
||
|
struct Scsi_Host *shost;
|
||
|
struct vhba_host *vhost;
|
||
|
int i;
|
||
|
|
||
|
vhba_can_queue = clamp(vhba_can_queue, 1, 256);
|
||
|
|
||
|
shost = scsi_host_alloc(&vhba_template, sizeof(struct vhba_host));
|
||
|
if (!shost) {
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
|
||
|
shost->max_channel = VHBA_MAX_BUS-1;
|
||
|
shost->max_id = VHBA_MAX_ID;
|
||
|
/* we don't support lun > 0 */
|
||
|
shost->max_lun = 1;
|
||
|
shost->max_cmd_len = MAX_COMMAND_SIZE;
|
||
|
shost->can_queue = vhba_can_queue;
|
||
|
shost->cmd_per_lun = vhba_can_queue;
|
||
|
|
||
|
vhost = (struct vhba_host *)shost->hostdata;
|
||
|
memset(vhost, 0, sizeof(struct vhba_host));
|
||
|
|
||
|
vhost->shost = shost;
|
||
|
vhost->num_devices = 0;
|
||
|
spin_lock_init(&vhost->dev_lock);
|
||
|
spin_lock_init(&vhost->cmd_lock);
|
||
|
INIT_WORK(&vhost->scan_devices, vhba_scan_devices);
|
||
|
vhost->cmd_next = 0;
|
||
|
vhost->commands = kzalloc(vhba_can_queue * sizeof(struct vhba_command), GFP_KERNEL);
|
||
|
if (!vhost->commands) {
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
|
||
|
for (i = 0; i < vhba_can_queue; i++) {
|
||
|
vhost->commands[i].status = VHBA_REQ_FREE;
|
||
|
}
|
||
|
|
||
|
platform_set_drvdata(pdev, vhost);
|
||
|
|
||
|
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 4, 0)
|
||
|
i = scsi_init_shared_tag_map(shost, vhba_can_queue);
|
||
|
if (i) return i;
|
||
|
#endif
|
||
|
|
||
|
if (scsi_add_host(shost, &pdev->dev)) {
|
||
|
scsi_host_put(shost);
|
||
|
return -ENOMEM;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
int vhba_remove (struct platform_device *pdev)
|
||
|
{
|
||
|
struct vhba_host *vhost;
|
||
|
struct Scsi_Host *shost;
|
||
|
|
||
|
vhost = platform_get_drvdata(pdev);
|
||
|
shost = vhost->shost;
|
||
|
|
||
|
scsi_remove_host(shost);
|
||
|
scsi_host_put(shost);
|
||
|
|
||
|
kfree(vhost->commands);
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
void vhba_release (struct device * dev)
|
||
|
{
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
static struct platform_device vhba_platform_device = {
|
||
|
.name = "vhba",
|
||
|
.id = -1,
|
||
|
.dev = {
|
||
|
.release = vhba_release,
|
||
|
},
|
||
|
};
|
||
|
|
||
|
static struct platform_driver vhba_platform_driver = {
|
||
|
.driver = {
|
||
|
.owner = THIS_MODULE,
|
||
|
.name = "vhba",
|
||
|
},
|
||
|
.probe = vhba_probe,
|
||
|
.remove = vhba_remove,
|
||
|
};
|
||
|
|
||
|
int __init vhba_init (void)
|
||
|
{
|
||
|
int ret;
|
||
|
|
||
|
ret = platform_device_register(&vhba_platform_device);
|
||
|
if (ret < 0) {
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
ret = platform_driver_register(&vhba_platform_driver);
|
||
|
if (ret < 0) {
|
||
|
platform_device_unregister(&vhba_platform_device);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
ret = misc_register(&vhba_miscdev);
|
||
|
if (ret < 0) {
|
||
|
platform_driver_unregister(&vhba_platform_driver);
|
||
|
platform_device_unregister(&vhba_platform_device);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
void __exit vhba_exit(void)
|
||
|
{
|
||
|
misc_deregister(&vhba_miscdev);
|
||
|
platform_driver_unregister(&vhba_platform_driver);
|
||
|
platform_device_unregister(&vhba_platform_device);
|
||
|
}
|
||
|
|
||
|
module_init(vhba_init);
|
||
|
module_exit(vhba_exit);
|
||
|
|