From cba900f94444c8c4cde6b5b4edfaeb6160b55ba3 Mon Sep 17 00:00:00 2001 From: "Jan Alexander Steffens (heftig)" Date: Mon, 26 Apr 2021 22:12:46 +0200 Subject: ZEN: Add VHBA driver remote https://github.com/cdemu/cdemu tag vhba-module-20240202 --- drivers/scsi/Kconfig | 2 + drivers/scsi/Makefile | 1 + drivers/scsi/vhba/Kconfig | 9 + drivers/scsi/vhba/Makefile | 4 + drivers/scsi/vhba/vhba.c | 1124 ++++++++++++++++++++++++++++++++++++ 5 files changed, 1140 insertions(+) create mode 100644 drivers/scsi/vhba/Kconfig create mode 100644 drivers/scsi/vhba/Makefile create mode 100644 drivers/scsi/vhba/vhba.c --- a/drivers/scsi/Kconfig +++ b/drivers/scsi/Kconfig @@ -1522,4 +1522,6 @@ endif # SCSI_LOWLEVEL source "drivers/scsi/device_handler/Kconfig" +source "drivers/scsi/vhba/Kconfig" + endmenu --- a/drivers/scsi/Makefile +++ b/drivers/scsi/Makefile @@ -153,6 +153,7 @@ obj-$(CONFIG_CHR_DEV_SCH) += ch.o obj-$(CONFIG_SCSI_ENCLOSURE) += ses.o obj-$(CONFIG_SCSI_HISI_SAS) += hisi_sas/ +obj-$(CONFIG_VHBA) += vhba/ # This goes last, so that "real" scsi devices probe earlier obj-$(CONFIG_SCSI_DEBUG) += scsi_debug.o --- /dev/null +++ b/drivers/scsi/vhba/Kconfig @@ -0,0 +1,9 @@ +config VHBA + tristate "Virtual (SCSI) Host Bus Adapter" + depends on SCSI + help + This is the in-kernel part of CDEmu, a CD/DVD-ROM device + emulator. + + This driver can also be built as a module. If so, the module + will be called vhba. --- /dev/null +++ b/drivers/scsi/vhba/Makefile @@ -0,0 +1,4 @@ +VHBA_VERSION := 20240202 + +obj-$(CONFIG_VHBA) += vhba.o +ccflags-y := -DVHBA_VERSION=\"$(VHBA_VERSION)\" -Werror --- /dev/null +++ b/drivers/scsi/vhba/vhba.c @@ -0,0 +1,1124 @@ +/* + * vhba.c + * + * Copyright (C) 2007-2012 Chia-I Wu + * + * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#define pr_fmt(fmt) "vhba: " fmt + +#include + +#include +#include +#include +#include +#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0) +#include +#else +#include +#endif +#include +#include +#include +#include +#include +#ifdef CONFIG_COMPAT +#include +#endif +#include +#include +#include +#include +#include +#include + + +MODULE_AUTHOR("Chia-I Wu"); +MODULE_VERSION(VHBA_VERSION); +MODULE_DESCRIPTION("Virtual SCSI HBA"); +MODULE_LICENSE("GPL"); + + +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 15, 0) +#define sdev_dbg(sdev, fmt, a...) \ + dev_dbg(&(sdev)->sdev_gendev, fmt, ##a) +#define scmd_dbg(scmd, fmt, a...) \ + dev_dbg(&(scmd)->device->sdev_gendev, fmt, ##a) +#endif + +#define VHBA_MAX_SECTORS_PER_IO 256 +#define VHBA_MAX_BUS 16 +#define VHBA_MAX_ID 16 +#define VHBA_MAX_DEVICES (VHBA_MAX_BUS * (VHBA_MAX_ID-1)) +#define VHBA_KBUF_SIZE PAGE_SIZE + +#define DATA_TO_DEVICE(dir) ((dir) == DMA_TO_DEVICE || (dir) == DMA_BIDIRECTIONAL) +#define DATA_FROM_DEVICE(dir) ((dir) == DMA_FROM_DEVICE || (dir) == DMA_BIDIRECTIONAL) + + +static int vhba_can_queue = 32; +module_param_named(can_queue, vhba_can_queue, int, 0); + + +enum vhba_req_state { + VHBA_REQ_FREE, + VHBA_REQ_PENDING, + VHBA_REQ_READING, + VHBA_REQ_SENT, + VHBA_REQ_WRITING, +}; + +struct vhba_command { + struct scsi_cmnd *cmd; + /* metatags are per-host. not to be confused with + queue tags that are usually per-lun */ + unsigned long metatag; + int status; + struct list_head entry; +}; + +struct vhba_device { + unsigned int num; + spinlock_t cmd_lock; + struct list_head cmd_list; + wait_queue_head_t cmd_wq; + atomic_t refcnt; + + unsigned char *kbuf; + size_t kbuf_size; +}; + +struct vhba_host { + struct Scsi_Host *shost; + spinlock_t cmd_lock; + int cmd_next; + struct vhba_command *commands; + spinlock_t dev_lock; + struct vhba_device *devices[VHBA_MAX_DEVICES]; + int num_devices; + DECLARE_BITMAP(chgmap, VHBA_MAX_DEVICES); + int chgtype[VHBA_MAX_DEVICES]; + struct work_struct scan_devices; +}; + +#define MAX_COMMAND_SIZE 16 + +struct vhba_request { + __u32 metatag; + __u32 lun; + __u8 cdb[MAX_COMMAND_SIZE]; + __u8 cdb_len; + __u32 data_len; +}; + +struct vhba_response { + __u32 metatag; + __u32 status; + __u32 data_len; +}; + + + +static struct vhba_command *vhba_alloc_command (void); +static void vhba_free_command (struct vhba_command *vcmd); + +static struct platform_device vhba_platform_device; + + + +/* These functions define a symmetric 1:1 mapping between device numbers and + the bus and id. We have reserved the last id per bus for the host itself. */ +static void devnum_to_bus_and_id(unsigned int devnum, unsigned int *bus, unsigned int *id) +{ + *bus = devnum / (VHBA_MAX_ID-1); + *id = devnum % (VHBA_MAX_ID-1); +} + +static unsigned int bus_and_id_to_devnum(unsigned int bus, unsigned int id) +{ + return (bus * (VHBA_MAX_ID-1)) + id; +} + +static struct vhba_device *vhba_device_alloc (void) +{ + struct vhba_device *vdev; + + vdev = kzalloc(sizeof(struct vhba_device), GFP_KERNEL); + if (!vdev) { + return NULL; + } + + spin_lock_init(&vdev->cmd_lock); + INIT_LIST_HEAD(&vdev->cmd_list); + init_waitqueue_head(&vdev->cmd_wq); + atomic_set(&vdev->refcnt, 1); + + vdev->kbuf = NULL; + vdev->kbuf_size = 0; + + return vdev; +} + +static void vhba_device_put (struct vhba_device *vdev) +{ + if (atomic_dec_and_test(&vdev->refcnt)) { + kfree(vdev); + } +} + +static struct vhba_device *vhba_device_get (struct vhba_device *vdev) +{ + atomic_inc(&vdev->refcnt); + + return vdev; +} + +static int vhba_device_queue (struct vhba_device *vdev, struct scsi_cmnd *cmd) +{ + struct vhba_host *vhost; + struct vhba_command *vcmd; + unsigned long flags; + + vhost = platform_get_drvdata(&vhba_platform_device); + + vcmd = vhba_alloc_command(); + if (!vcmd) { + return SCSI_MLQUEUE_HOST_BUSY; + } + + vcmd->cmd = cmd; + + spin_lock_irqsave(&vdev->cmd_lock, flags); +#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 15, 0) + vcmd->metatag = scsi_cmd_to_rq(vcmd->cmd)->tag; +#else + vcmd->metatag = vcmd->cmd->request->tag; +#endif + list_add_tail(&vcmd->entry, &vdev->cmd_list); + spin_unlock_irqrestore(&vdev->cmd_lock, flags); + + wake_up_interruptible(&vdev->cmd_wq); + + return 0; +} + +static int vhba_device_dequeue (struct vhba_device *vdev, struct scsi_cmnd *cmd) +{ + struct vhba_command *vcmd; + int retval; + unsigned long flags; + + spin_lock_irqsave(&vdev->cmd_lock, flags); + list_for_each_entry(vcmd, &vdev->cmd_list, entry) { + if (vcmd->cmd == cmd) { + list_del_init(&vcmd->entry); + break; + } + } + + /* command not found */ + if (&vcmd->entry == &vdev->cmd_list) { + spin_unlock_irqrestore(&vdev->cmd_lock, flags); + return SUCCESS; + } + + while (vcmd->status == VHBA_REQ_READING || vcmd->status == VHBA_REQ_WRITING) { + spin_unlock_irqrestore(&vdev->cmd_lock, flags); + scmd_dbg(cmd, "wait for I/O before aborting\n"); + schedule_timeout(1); + spin_lock_irqsave(&vdev->cmd_lock, flags); + } + + retval = (vcmd->status == VHBA_REQ_SENT) ? FAILED : SUCCESS; + + vhba_free_command(vcmd); + + spin_unlock_irqrestore(&vdev->cmd_lock, flags); + + return retval; +} + +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 19, 0) +static int vhba_slave_alloc(struct scsi_device *sdev) +{ + struct Scsi_Host *shost = sdev->host; + + sdev_dbg(sdev, "enabling tagging (queue depth: %i).\n", sdev->queue_depth); +#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 17, 0) + if (!shost_use_blk_mq(shost) && shost->bqt) { +#else + if (shost->bqt) { +#endif + blk_queue_init_tags(sdev->request_queue, sdev->queue_depth, shost->bqt); + } + scsi_adjust_queue_depth(sdev, 0, sdev->queue_depth); + + return 0; +} +#endif + +static void vhba_scan_devices_add (struct vhba_host *vhost, int bus, int id) +{ + struct scsi_device *sdev; + + sdev = scsi_device_lookup(vhost->shost, bus, id, 0); + if (!sdev) { + scsi_add_device(vhost->shost, bus, id, 0); + } else { + dev_warn(&vhost->shost->shost_gendev, "tried to add an already-existing device %d:%d:0!\n", bus, id); + scsi_device_put(sdev); + } +} + +static void vhba_scan_devices_remove (struct vhba_host *vhost, int bus, int id) +{ + struct scsi_device *sdev; + + sdev = scsi_device_lookup(vhost->shost, bus, id, 0); + if (sdev) { + scsi_remove_device(sdev); + scsi_device_put(sdev); + } else { + dev_warn(&vhost->shost->shost_gendev, "tried to remove non-existing device %d:%d:0!\n", bus, id); + } +} + +static void vhba_scan_devices (struct work_struct *work) +{ + struct vhba_host *vhost = container_of(work, struct vhba_host, scan_devices); + unsigned long flags; + int change, exists; + unsigned int devnum; + unsigned int bus, id; + + for (;;) { + spin_lock_irqsave(&vhost->dev_lock, flags); + + devnum = find_first_bit(vhost->chgmap, VHBA_MAX_DEVICES); + if (devnum >= VHBA_MAX_DEVICES) { + spin_unlock_irqrestore(&vhost->dev_lock, flags); + break; + } + change = vhost->chgtype[devnum]; + exists = vhost->devices[devnum] != NULL; + + vhost->chgtype[devnum] = 0; + clear_bit(devnum, vhost->chgmap); + + spin_unlock_irqrestore(&vhost->dev_lock, flags); + + devnum_to_bus_and_id(devnum, &bus, &id); + + if (change < 0) { + dev_dbg(&vhost->shost->shost_gendev, "trying to remove target %d:%d:0\n", bus, id); + vhba_scan_devices_remove(vhost, bus, id); + } else if (change > 0) { + dev_dbg(&vhost->shost->shost_gendev, "trying to add target %d:%d:0\n", bus, id); + vhba_scan_devices_add(vhost, bus, id); + } else { + /* quick sequence of add/remove or remove/add; we determine + which one it was by checking if device structure exists */ + if (exists) { + /* remove followed by add: remove and (re)add */ + dev_dbg(&vhost->shost->shost_gendev, "trying to (re)add target %d:%d:0\n", bus, id); + vhba_scan_devices_remove(vhost, bus, id); + vhba_scan_devices_add(vhost, bus, id); + } else { + /* add followed by remove: no-op */ + dev_dbg(&vhost->shost->shost_gendev, "no-op for target %d:%d:0\n", bus, id); + } + } + } +} + +static int vhba_add_device (struct vhba_device *vdev) +{ + struct vhba_host *vhost; + unsigned int devnum; + unsigned long flags; + + vhost = platform_get_drvdata(&vhba_platform_device); + + vhba_device_get(vdev); + + spin_lock_irqsave(&vhost->dev_lock, flags); + if (vhost->num_devices >= VHBA_MAX_DEVICES) { + spin_unlock_irqrestore(&vhost->dev_lock, flags); + vhba_device_put(vdev); + return -EBUSY; + } + + for (devnum = 0; devnum < VHBA_MAX_DEVICES; devnum++) { + if (vhost->devices[devnum] == NULL) { + vdev->num = devnum; + vhost->devices[devnum] = vdev; + vhost->num_devices++; + set_bit(devnum, vhost->chgmap); + vhost->chgtype[devnum]++; + break; + } + } + spin_unlock_irqrestore(&vhost->dev_lock, flags); + + schedule_work(&vhost->scan_devices); + + return 0; +} + +static int vhba_remove_device (struct vhba_device *vdev) +{ + struct vhba_host *vhost; + unsigned long flags; + + vhost = platform_get_drvdata(&vhba_platform_device); + + spin_lock_irqsave(&vhost->dev_lock, flags); + set_bit(vdev->num, vhost->chgmap); + vhost->chgtype[vdev->num]--; + vhost->devices[vdev->num] = NULL; + vhost->num_devices--; + spin_unlock_irqrestore(&vhost->dev_lock, flags); + + vhba_device_put(vdev); + + schedule_work(&vhost->scan_devices); + + return 0; +} + +static struct vhba_device *vhba_lookup_device (int devnum) +{ + struct vhba_host *vhost; + struct vhba_device *vdev = NULL; + unsigned long flags; + + vhost = platform_get_drvdata(&vhba_platform_device); + + if (likely(devnum < VHBA_MAX_DEVICES)) { + 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; +} + +static 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; +} + +static 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); +} + +static 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; +} + +static 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 +}; + +static 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; +} + +static 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; +} + +static 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; +} + +static 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; +} + +static 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; +} + +static 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; +} + +static 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; +} + +static 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 +static 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 + +static 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; +} + +static 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; +} + +static 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, +}; + +static 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; +} + +static 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; +} + +static 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, +}; + +static 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; +} + +static 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); +