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![Andy Grover](/assets/img/avatar_default.png)
TCMU requires more work to correctly handle both user handlers that want all SCSI commands (pass_level=0) for a se_device, and also handlers that just want I/O commands and let the others be emulated by the kernel (pass_level=1). Only support the latter for now. For full passthrough, we will need to support a second se_subsystem_api template, due to configfs attributes being different between the two modes. Thus pass_level is extraneous, and we can remove it. The ABI break for TCMU v2 is already applied for this release, so it's best to do this now to avoid another ABI break in the future. Signed-off-by: Andy Grover <agrover@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
1168 lines
29 KiB
C
1168 lines
29 KiB
C
/*
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* Copyright (C) 2013 Shaohua Li <shli@kernel.org>
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* Copyright (C) 2014 Red Hat, Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <linux/spinlock.h>
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#include <linux/module.h>
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#include <linux/idr.h>
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#include <linux/timer.h>
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#include <linux/parser.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_host.h>
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#include <linux/uio_driver.h>
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#include <net/genetlink.h>
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#include <target/target_core_base.h>
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#include <target/target_core_fabric.h>
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#include <target/target_core_backend.h>
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#include <target/target_core_backend_configfs.h>
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#include <linux/target_core_user.h>
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/*
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* Define a shared-memory interface for LIO to pass SCSI commands and
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* data to userspace for processing. This is to allow backends that
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* are too complex for in-kernel support to be possible.
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*
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* It uses the UIO framework to do a lot of the device-creation and
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* introspection work for us.
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*
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* See the .h file for how the ring is laid out. Note that while the
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* command ring is defined, the particulars of the data area are
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* not. Offset values in the command entry point to other locations
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* internal to the mmap()ed area. There is separate space outside the
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* command ring for data buffers. This leaves maximum flexibility for
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* moving buffer allocations, or even page flipping or other
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* allocation techniques, without altering the command ring layout.
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*
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* SECURITY:
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* The user process must be assumed to be malicious. There's no way to
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* prevent it breaking the command ring protocol if it wants, but in
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* order to prevent other issues we must only ever read *data* from
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* the shared memory area, not offsets or sizes. This applies to
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* command ring entries as well as the mailbox. Extra code needed for
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* this may have a 'UAM' comment.
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*/
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#define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
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#define CMDR_SIZE (16 * 4096)
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#define DATA_SIZE (257 * 4096)
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#define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
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static struct device *tcmu_root_device;
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struct tcmu_hba {
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u32 host_id;
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};
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#define TCMU_CONFIG_LEN 256
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struct tcmu_dev {
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struct se_device se_dev;
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char *name;
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struct se_hba *hba;
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#define TCMU_DEV_BIT_OPEN 0
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#define TCMU_DEV_BIT_BROKEN 1
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unsigned long flags;
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struct uio_info uio_info;
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struct tcmu_mailbox *mb_addr;
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size_t dev_size;
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u32 cmdr_size;
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u32 cmdr_last_cleaned;
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/* Offset of data ring from start of mb */
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size_t data_off;
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size_t data_size;
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/* Ring head + tail values. */
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/* Must add data_off and mb_addr to get the address */
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size_t data_head;
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size_t data_tail;
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wait_queue_head_t wait_cmdr;
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/* TODO should this be a mutex? */
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spinlock_t cmdr_lock;
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struct idr commands;
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spinlock_t commands_lock;
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struct timer_list timeout;
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char dev_config[TCMU_CONFIG_LEN];
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};
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#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
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#define CMDR_OFF sizeof(struct tcmu_mailbox)
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struct tcmu_cmd {
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struct se_cmd *se_cmd;
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struct tcmu_dev *tcmu_dev;
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uint16_t cmd_id;
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/* Can't use se_cmd->data_length when cleaning up expired cmds, because if
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cmd has been completed then accessing se_cmd is off limits */
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size_t data_length;
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unsigned long deadline;
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#define TCMU_CMD_BIT_EXPIRED 0
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unsigned long flags;
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};
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static struct kmem_cache *tcmu_cmd_cache;
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/* multicast group */
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enum tcmu_multicast_groups {
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TCMU_MCGRP_CONFIG,
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};
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static const struct genl_multicast_group tcmu_mcgrps[] = {
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[TCMU_MCGRP_CONFIG] = { .name = "config", },
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};
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/* Our generic netlink family */
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static struct genl_family tcmu_genl_family = {
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.id = GENL_ID_GENERATE,
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.hdrsize = 0,
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.name = "TCM-USER",
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.version = 1,
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.maxattr = TCMU_ATTR_MAX,
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.mcgrps = tcmu_mcgrps,
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.n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
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};
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static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
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{
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struct se_device *se_dev = se_cmd->se_dev;
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struct tcmu_dev *udev = TCMU_DEV(se_dev);
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struct tcmu_cmd *tcmu_cmd;
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int cmd_id;
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tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_KERNEL);
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if (!tcmu_cmd)
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return NULL;
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tcmu_cmd->se_cmd = se_cmd;
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tcmu_cmd->tcmu_dev = udev;
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tcmu_cmd->data_length = se_cmd->data_length;
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tcmu_cmd->deadline = jiffies + msecs_to_jiffies(TCMU_TIME_OUT);
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idr_preload(GFP_KERNEL);
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spin_lock_irq(&udev->commands_lock);
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cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 0,
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USHRT_MAX, GFP_NOWAIT);
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spin_unlock_irq(&udev->commands_lock);
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idr_preload_end();
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if (cmd_id < 0) {
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kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
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return NULL;
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}
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tcmu_cmd->cmd_id = cmd_id;
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return tcmu_cmd;
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}
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static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
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{
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unsigned long offset = (unsigned long) vaddr & ~PAGE_MASK;
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size = round_up(size+offset, PAGE_SIZE);
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vaddr -= offset;
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while (size) {
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flush_dcache_page(virt_to_page(vaddr));
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size -= PAGE_SIZE;
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}
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}
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/*
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* Some ring helper functions. We don't assume size is a power of 2 so
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* we can't use circ_buf.h.
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*/
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static inline size_t spc_used(size_t head, size_t tail, size_t size)
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{
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int diff = head - tail;
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if (diff >= 0)
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return diff;
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else
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return size + diff;
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}
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static inline size_t spc_free(size_t head, size_t tail, size_t size)
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{
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/* Keep 1 byte unused or we can't tell full from empty */
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return (size - spc_used(head, tail, size) - 1);
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}
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static inline size_t head_to_end(size_t head, size_t size)
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{
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return size - head;
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}
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#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
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/*
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* We can't queue a command until we have space available on the cmd ring *and* space
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* space avail on the data ring.
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*
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* Called with ring lock held.
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*/
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static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t data_needed)
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{
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struct tcmu_mailbox *mb = udev->mb_addr;
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size_t space;
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u32 cmd_head;
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size_t cmd_needed;
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tcmu_flush_dcache_range(mb, sizeof(*mb));
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cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
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/*
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* If cmd end-of-ring space is too small then we need space for a NOP plus
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* original cmd - cmds are internally contiguous.
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*/
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if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
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cmd_needed = cmd_size;
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else
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cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
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space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
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if (space < cmd_needed) {
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pr_debug("no cmd space: %u %u %u\n", cmd_head,
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udev->cmdr_last_cleaned, udev->cmdr_size);
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return false;
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}
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space = spc_free(udev->data_head, udev->data_tail, udev->data_size);
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if (space < data_needed) {
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pr_debug("no data space: %zu %zu %zu\n", udev->data_head,
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udev->data_tail, udev->data_size);
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return false;
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}
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return true;
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}
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static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
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{
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struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
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struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
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size_t base_command_size, command_size;
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struct tcmu_mailbox *mb;
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struct tcmu_cmd_entry *entry;
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int i;
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struct scatterlist *sg;
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struct iovec *iov;
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int iov_cnt = 0;
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uint32_t cmd_head;
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uint64_t cdb_off;
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if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
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return -EINVAL;
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/*
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* Must be a certain minimum size for response sense info, but
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* also may be larger if the iov array is large.
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*
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* iovs = sgl_nents+1, for end-of-ring case, plus another 1
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* b/c size == offsetof one-past-element.
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*/
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base_command_size = max(offsetof(struct tcmu_cmd_entry,
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req.iov[se_cmd->t_data_nents + 2]),
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sizeof(struct tcmu_cmd_entry));
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command_size = base_command_size
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+ round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE);
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WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
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spin_lock_irq(&udev->cmdr_lock);
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mb = udev->mb_addr;
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cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
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if ((command_size > (udev->cmdr_size / 2))
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|| tcmu_cmd->data_length > (udev->data_size - 1))
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pr_warn("TCMU: Request of size %zu/%zu may be too big for %u/%zu "
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"cmd/data ring buffers\n", command_size, tcmu_cmd->data_length,
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udev->cmdr_size, udev->data_size);
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while (!is_ring_space_avail(udev, command_size, tcmu_cmd->data_length)) {
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int ret;
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DEFINE_WAIT(__wait);
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prepare_to_wait(&udev->wait_cmdr, &__wait, TASK_INTERRUPTIBLE);
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pr_debug("sleeping for ring space\n");
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spin_unlock_irq(&udev->cmdr_lock);
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ret = schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT));
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finish_wait(&udev->wait_cmdr, &__wait);
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if (!ret) {
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pr_warn("tcmu: command timed out\n");
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return -ETIMEDOUT;
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}
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spin_lock_irq(&udev->cmdr_lock);
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/* We dropped cmdr_lock, cmd_head is stale */
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cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
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}
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/* Insert a PAD if end-of-ring space is too small */
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if (head_to_end(cmd_head, udev->cmdr_size) < command_size) {
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size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
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entry = (void *) mb + CMDR_OFF + cmd_head;
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tcmu_flush_dcache_range(entry, sizeof(*entry));
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tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
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tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
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entry->hdr.cmd_id = 0; /* not used for PAD */
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entry->hdr.kflags = 0;
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entry->hdr.uflags = 0;
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UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
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cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
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WARN_ON(cmd_head != 0);
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}
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entry = (void *) mb + CMDR_OFF + cmd_head;
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tcmu_flush_dcache_range(entry, sizeof(*entry));
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tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
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tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
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entry->hdr.cmd_id = tcmu_cmd->cmd_id;
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entry->hdr.kflags = 0;
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entry->hdr.uflags = 0;
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/*
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* Fix up iovecs, and handle if allocation in data ring wrapped.
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*/
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iov = &entry->req.iov[0];
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for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) {
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size_t copy_bytes = min((size_t)sg->length,
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head_to_end(udev->data_head, udev->data_size));
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void *from = kmap_atomic(sg_page(sg)) + sg->offset;
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void *to = (void *) mb + udev->data_off + udev->data_head;
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if (tcmu_cmd->se_cmd->data_direction == DMA_TO_DEVICE) {
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memcpy(to, from, copy_bytes);
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tcmu_flush_dcache_range(to, copy_bytes);
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}
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/* Even iov_base is relative to mb_addr */
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iov->iov_len = copy_bytes;
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iov->iov_base = (void __user *) udev->data_off +
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udev->data_head;
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iov_cnt++;
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iov++;
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UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size);
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/* Uh oh, we wrapped the buffer. Must split sg across 2 iovs. */
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if (sg->length != copy_bytes) {
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from += copy_bytes;
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copy_bytes = sg->length - copy_bytes;
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iov->iov_len = copy_bytes;
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iov->iov_base = (void __user *) udev->data_off +
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udev->data_head;
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if (se_cmd->data_direction == DMA_TO_DEVICE) {
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to = (void *) mb + udev->data_off + udev->data_head;
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memcpy(to, from, copy_bytes);
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tcmu_flush_dcache_range(to, copy_bytes);
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}
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iov_cnt++;
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iov++;
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UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size);
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}
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kunmap_atomic(from);
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}
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entry->req.iov_cnt = iov_cnt;
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entry->req.iov_bidi_cnt = 0;
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entry->req.iov_dif_cnt = 0;
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/* All offsets relative to mb_addr, not start of entry! */
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cdb_off = CMDR_OFF + cmd_head + base_command_size;
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memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
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entry->req.cdb_off = cdb_off;
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tcmu_flush_dcache_range(entry, sizeof(*entry));
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UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
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tcmu_flush_dcache_range(mb, sizeof(*mb));
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spin_unlock_irq(&udev->cmdr_lock);
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/* TODO: only if FLUSH and FUA? */
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uio_event_notify(&udev->uio_info);
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mod_timer(&udev->timeout,
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round_jiffies_up(jiffies + msecs_to_jiffies(TCMU_TIME_OUT)));
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return 0;
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}
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static int tcmu_queue_cmd(struct se_cmd *se_cmd)
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{
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struct se_device *se_dev = se_cmd->se_dev;
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struct tcmu_dev *udev = TCMU_DEV(se_dev);
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struct tcmu_cmd *tcmu_cmd;
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int ret;
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tcmu_cmd = tcmu_alloc_cmd(se_cmd);
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if (!tcmu_cmd)
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return -ENOMEM;
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ret = tcmu_queue_cmd_ring(tcmu_cmd);
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if (ret < 0) {
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pr_err("TCMU: Could not queue command\n");
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spin_lock_irq(&udev->commands_lock);
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idr_remove(&udev->commands, tcmu_cmd->cmd_id);
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spin_unlock_irq(&udev->commands_lock);
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kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
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}
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return ret;
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}
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static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
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{
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struct se_cmd *se_cmd = cmd->se_cmd;
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struct tcmu_dev *udev = cmd->tcmu_dev;
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if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
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/* cmd has been completed already from timeout, just reclaim data
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ring space */
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UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
|
|
return;
|
|
}
|
|
|
|
if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
|
|
UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
|
|
pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
|
|
cmd->se_cmd);
|
|
transport_generic_request_failure(cmd->se_cmd,
|
|
TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
|
|
cmd->se_cmd = NULL;
|
|
kmem_cache_free(tcmu_cmd_cache, cmd);
|
|
return;
|
|
}
|
|
|
|
if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
|
|
memcpy(se_cmd->sense_buffer, entry->rsp.sense_buffer,
|
|
se_cmd->scsi_sense_length);
|
|
|
|
UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
|
|
}
|
|
else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
/* It'd be easier to look at entry's iovec again, but UAM */
|
|
for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) {
|
|
size_t copy_bytes;
|
|
void *to;
|
|
void *from;
|
|
|
|
copy_bytes = min((size_t)sg->length,
|
|
head_to_end(udev->data_tail, udev->data_size));
|
|
|
|
to = kmap_atomic(sg_page(sg)) + sg->offset;
|
|
WARN_ON(sg->length + sg->offset > PAGE_SIZE);
|
|
from = (void *) udev->mb_addr + udev->data_off + udev->data_tail;
|
|
tcmu_flush_dcache_range(from, copy_bytes);
|
|
memcpy(to, from, copy_bytes);
|
|
|
|
UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size);
|
|
|
|
/* Uh oh, wrapped the data buffer for this sg's data */
|
|
if (sg->length != copy_bytes) {
|
|
from = (void *) udev->mb_addr + udev->data_off + udev->data_tail;
|
|
WARN_ON(udev->data_tail);
|
|
to += copy_bytes;
|
|
copy_bytes = sg->length - copy_bytes;
|
|
tcmu_flush_dcache_range(from, copy_bytes);
|
|
memcpy(to, from, copy_bytes);
|
|
|
|
UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size);
|
|
}
|
|
|
|
kunmap_atomic(to);
|
|
}
|
|
|
|
} else if (se_cmd->data_direction == DMA_TO_DEVICE) {
|
|
UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
|
|
} else {
|
|
pr_warn("TCMU: data direction was %d!\n", se_cmd->data_direction);
|
|
}
|
|
|
|
target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
|
|
cmd->se_cmd = NULL;
|
|
|
|
kmem_cache_free(tcmu_cmd_cache, cmd);
|
|
}
|
|
|
|
static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
|
|
{
|
|
struct tcmu_mailbox *mb;
|
|
LIST_HEAD(cpl_cmds);
|
|
unsigned long flags;
|
|
int handled = 0;
|
|
|
|
if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
|
|
pr_err("ring broken, not handling completions\n");
|
|
return 0;
|
|
}
|
|
|
|
spin_lock_irqsave(&udev->cmdr_lock, flags);
|
|
|
|
mb = udev->mb_addr;
|
|
tcmu_flush_dcache_range(mb, sizeof(*mb));
|
|
|
|
while (udev->cmdr_last_cleaned != ACCESS_ONCE(mb->cmd_tail)) {
|
|
|
|
struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
|
|
struct tcmu_cmd *cmd;
|
|
|
|
tcmu_flush_dcache_range(entry, sizeof(*entry));
|
|
|
|
if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD) {
|
|
UPDATE_HEAD(udev->cmdr_last_cleaned,
|
|
tcmu_hdr_get_len(entry->hdr.len_op),
|
|
udev->cmdr_size);
|
|
continue;
|
|
}
|
|
WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
|
|
|
|
spin_lock(&udev->commands_lock);
|
|
cmd = idr_find(&udev->commands, entry->hdr.cmd_id);
|
|
if (cmd)
|
|
idr_remove(&udev->commands, cmd->cmd_id);
|
|
spin_unlock(&udev->commands_lock);
|
|
|
|
if (!cmd) {
|
|
pr_err("cmd_id not found, ring is broken\n");
|
|
set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
|
|
break;
|
|
}
|
|
|
|
tcmu_handle_completion(cmd, entry);
|
|
|
|
UPDATE_HEAD(udev->cmdr_last_cleaned,
|
|
tcmu_hdr_get_len(entry->hdr.len_op),
|
|
udev->cmdr_size);
|
|
|
|
handled++;
|
|
}
|
|
|
|
if (mb->cmd_tail == mb->cmd_head)
|
|
del_timer(&udev->timeout); /* no more pending cmds */
|
|
|
|
spin_unlock_irqrestore(&udev->cmdr_lock, flags);
|
|
|
|
wake_up(&udev->wait_cmdr);
|
|
|
|
return handled;
|
|
}
|
|
|
|
static int tcmu_check_expired_cmd(int id, void *p, void *data)
|
|
{
|
|
struct tcmu_cmd *cmd = p;
|
|
|
|
if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
|
|
return 0;
|
|
|
|
if (!time_after(cmd->deadline, jiffies))
|
|
return 0;
|
|
|
|
set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
|
|
target_complete_cmd(cmd->se_cmd, SAM_STAT_CHECK_CONDITION);
|
|
cmd->se_cmd = NULL;
|
|
|
|
kmem_cache_free(tcmu_cmd_cache, cmd);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void tcmu_device_timedout(unsigned long data)
|
|
{
|
|
struct tcmu_dev *udev = (struct tcmu_dev *)data;
|
|
unsigned long flags;
|
|
int handled;
|
|
|
|
handled = tcmu_handle_completions(udev);
|
|
|
|
pr_warn("%d completions handled from timeout\n", handled);
|
|
|
|
spin_lock_irqsave(&udev->commands_lock, flags);
|
|
idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
|
|
spin_unlock_irqrestore(&udev->commands_lock, flags);
|
|
|
|
/*
|
|
* We don't need to wakeup threads on wait_cmdr since they have their
|
|
* own timeout.
|
|
*/
|
|
}
|
|
|
|
static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
|
|
{
|
|
struct tcmu_hba *tcmu_hba;
|
|
|
|
tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
|
|
if (!tcmu_hba)
|
|
return -ENOMEM;
|
|
|
|
tcmu_hba->host_id = host_id;
|
|
hba->hba_ptr = tcmu_hba;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void tcmu_detach_hba(struct se_hba *hba)
|
|
{
|
|
kfree(hba->hba_ptr);
|
|
hba->hba_ptr = NULL;
|
|
}
|
|
|
|
static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
|
|
{
|
|
struct tcmu_dev *udev;
|
|
|
|
udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
|
|
if (!udev)
|
|
return NULL;
|
|
|
|
udev->name = kstrdup(name, GFP_KERNEL);
|
|
if (!udev->name) {
|
|
kfree(udev);
|
|
return NULL;
|
|
}
|
|
|
|
udev->hba = hba;
|
|
|
|
init_waitqueue_head(&udev->wait_cmdr);
|
|
spin_lock_init(&udev->cmdr_lock);
|
|
|
|
idr_init(&udev->commands);
|
|
spin_lock_init(&udev->commands_lock);
|
|
|
|
setup_timer(&udev->timeout, tcmu_device_timedout,
|
|
(unsigned long)udev);
|
|
|
|
return &udev->se_dev;
|
|
}
|
|
|
|
static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
|
|
{
|
|
struct tcmu_dev *tcmu_dev = container_of(info, struct tcmu_dev, uio_info);
|
|
|
|
tcmu_handle_completions(tcmu_dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* mmap code from uio.c. Copied here because we want to hook mmap()
|
|
* and this stuff must come along.
|
|
*/
|
|
static int tcmu_find_mem_index(struct vm_area_struct *vma)
|
|
{
|
|
struct tcmu_dev *udev = vma->vm_private_data;
|
|
struct uio_info *info = &udev->uio_info;
|
|
|
|
if (vma->vm_pgoff < MAX_UIO_MAPS) {
|
|
if (info->mem[vma->vm_pgoff].size == 0)
|
|
return -1;
|
|
return (int)vma->vm_pgoff;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static int tcmu_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
|
|
{
|
|
struct tcmu_dev *udev = vma->vm_private_data;
|
|
struct uio_info *info = &udev->uio_info;
|
|
struct page *page;
|
|
unsigned long offset;
|
|
void *addr;
|
|
|
|
int mi = tcmu_find_mem_index(vma);
|
|
if (mi < 0)
|
|
return VM_FAULT_SIGBUS;
|
|
|
|
/*
|
|
* We need to subtract mi because userspace uses offset = N*PAGE_SIZE
|
|
* to use mem[N].
|
|
*/
|
|
offset = (vmf->pgoff - mi) << PAGE_SHIFT;
|
|
|
|
addr = (void *)(unsigned long)info->mem[mi].addr + offset;
|
|
if (info->mem[mi].memtype == UIO_MEM_LOGICAL)
|
|
page = virt_to_page(addr);
|
|
else
|
|
page = vmalloc_to_page(addr);
|
|
get_page(page);
|
|
vmf->page = page;
|
|
return 0;
|
|
}
|
|
|
|
static const struct vm_operations_struct tcmu_vm_ops = {
|
|
.fault = tcmu_vma_fault,
|
|
};
|
|
|
|
static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
|
|
{
|
|
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
|
|
|
|
vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
|
|
vma->vm_ops = &tcmu_vm_ops;
|
|
|
|
vma->vm_private_data = udev;
|
|
|
|
/* Ensure the mmap is exactly the right size */
|
|
if (vma_pages(vma) != (TCMU_RING_SIZE >> PAGE_SHIFT))
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tcmu_open(struct uio_info *info, struct inode *inode)
|
|
{
|
|
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
|
|
|
|
/* O_EXCL not supported for char devs, so fake it? */
|
|
if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
|
|
return -EBUSY;
|
|
|
|
pr_debug("open\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tcmu_release(struct uio_info *info, struct inode *inode)
|
|
{
|
|
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
|
|
|
|
clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
|
|
|
|
pr_debug("close\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tcmu_netlink_event(enum tcmu_genl_cmd cmd, const char *name, int minor)
|
|
{
|
|
struct sk_buff *skb;
|
|
void *msg_header;
|
|
int ret = -ENOMEM;
|
|
|
|
skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
|
|
if (!skb)
|
|
return ret;
|
|
|
|
msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
|
|
if (!msg_header)
|
|
goto free_skb;
|
|
|
|
ret = nla_put_string(skb, TCMU_ATTR_DEVICE, name);
|
|
if (ret < 0)
|
|
goto free_skb;
|
|
|
|
ret = nla_put_u32(skb, TCMU_ATTR_MINOR, minor);
|
|
if (ret < 0)
|
|
goto free_skb;
|
|
|
|
genlmsg_end(skb, msg_header);
|
|
|
|
ret = genlmsg_multicast(&tcmu_genl_family, skb, 0,
|
|
TCMU_MCGRP_CONFIG, GFP_KERNEL);
|
|
|
|
/* We don't care if no one is listening */
|
|
if (ret == -ESRCH)
|
|
ret = 0;
|
|
|
|
return ret;
|
|
free_skb:
|
|
nlmsg_free(skb);
|
|
return ret;
|
|
}
|
|
|
|
static int tcmu_configure_device(struct se_device *dev)
|
|
{
|
|
struct tcmu_dev *udev = TCMU_DEV(dev);
|
|
struct tcmu_hba *hba = udev->hba->hba_ptr;
|
|
struct uio_info *info;
|
|
struct tcmu_mailbox *mb;
|
|
size_t size;
|
|
size_t used;
|
|
int ret = 0;
|
|
char *str;
|
|
|
|
info = &udev->uio_info;
|
|
|
|
size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name,
|
|
udev->dev_config);
|
|
size += 1; /* for \0 */
|
|
str = kmalloc(size, GFP_KERNEL);
|
|
if (!str)
|
|
return -ENOMEM;
|
|
|
|
used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name);
|
|
|
|
if (udev->dev_config[0])
|
|
snprintf(str + used, size - used, "/%s", udev->dev_config);
|
|
|
|
info->name = str;
|
|
|
|
udev->mb_addr = vzalloc(TCMU_RING_SIZE);
|
|
if (!udev->mb_addr) {
|
|
ret = -ENOMEM;
|
|
goto err_vzalloc;
|
|
}
|
|
|
|
/* mailbox fits in first part of CMDR space */
|
|
udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
|
|
udev->data_off = CMDR_SIZE;
|
|
udev->data_size = TCMU_RING_SIZE - CMDR_SIZE;
|
|
|
|
mb = udev->mb_addr;
|
|
mb->version = TCMU_MAILBOX_VERSION;
|
|
mb->cmdr_off = CMDR_OFF;
|
|
mb->cmdr_size = udev->cmdr_size;
|
|
|
|
WARN_ON(!PAGE_ALIGNED(udev->data_off));
|
|
WARN_ON(udev->data_size % PAGE_SIZE);
|
|
|
|
info->version = xstr(TCMU_MAILBOX_VERSION);
|
|
|
|
info->mem[0].name = "tcm-user command & data buffer";
|
|
info->mem[0].addr = (phys_addr_t) udev->mb_addr;
|
|
info->mem[0].size = TCMU_RING_SIZE;
|
|
info->mem[0].memtype = UIO_MEM_VIRTUAL;
|
|
|
|
info->irqcontrol = tcmu_irqcontrol;
|
|
info->irq = UIO_IRQ_CUSTOM;
|
|
|
|
info->mmap = tcmu_mmap;
|
|
info->open = tcmu_open;
|
|
info->release = tcmu_release;
|
|
|
|
ret = uio_register_device(tcmu_root_device, info);
|
|
if (ret)
|
|
goto err_register;
|
|
|
|
/* Other attributes can be configured in userspace */
|
|
dev->dev_attrib.hw_block_size = 512;
|
|
dev->dev_attrib.hw_max_sectors = 128;
|
|
dev->dev_attrib.hw_queue_depth = 128;
|
|
|
|
ret = tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE, udev->uio_info.name,
|
|
udev->uio_info.uio_dev->minor);
|
|
if (ret)
|
|
goto err_netlink;
|
|
|
|
return 0;
|
|
|
|
err_netlink:
|
|
uio_unregister_device(&udev->uio_info);
|
|
err_register:
|
|
vfree(udev->mb_addr);
|
|
err_vzalloc:
|
|
kfree(info->name);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int tcmu_check_pending_cmd(int id, void *p, void *data)
|
|
{
|
|
struct tcmu_cmd *cmd = p;
|
|
|
|
if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
|
|
return 0;
|
|
return -EINVAL;
|
|
}
|
|
|
|
static void tcmu_free_device(struct se_device *dev)
|
|
{
|
|
struct tcmu_dev *udev = TCMU_DEV(dev);
|
|
int i;
|
|
|
|
del_timer_sync(&udev->timeout);
|
|
|
|
vfree(udev->mb_addr);
|
|
|
|
/* Upper layer should drain all requests before calling this */
|
|
spin_lock_irq(&udev->commands_lock);
|
|
i = idr_for_each(&udev->commands, tcmu_check_pending_cmd, NULL);
|
|
idr_destroy(&udev->commands);
|
|
spin_unlock_irq(&udev->commands_lock);
|
|
WARN_ON(i);
|
|
|
|
/* Device was configured */
|
|
if (udev->uio_info.uio_dev) {
|
|
tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE, udev->uio_info.name,
|
|
udev->uio_info.uio_dev->minor);
|
|
|
|
uio_unregister_device(&udev->uio_info);
|
|
kfree(udev->uio_info.name);
|
|
kfree(udev->name);
|
|
}
|
|
|
|
kfree(udev);
|
|
}
|
|
|
|
enum {
|
|
Opt_dev_config, Opt_dev_size, Opt_err,
|
|
};
|
|
|
|
static match_table_t tokens = {
|
|
{Opt_dev_config, "dev_config=%s"},
|
|
{Opt_dev_size, "dev_size=%u"},
|
|
{Opt_err, NULL}
|
|
};
|
|
|
|
static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
|
|
const char *page, ssize_t count)
|
|
{
|
|
struct tcmu_dev *udev = TCMU_DEV(dev);
|
|
char *orig, *ptr, *opts, *arg_p;
|
|
substring_t args[MAX_OPT_ARGS];
|
|
int ret = 0, token;
|
|
|
|
opts = kstrdup(page, GFP_KERNEL);
|
|
if (!opts)
|
|
return -ENOMEM;
|
|
|
|
orig = opts;
|
|
|
|
while ((ptr = strsep(&opts, ",\n")) != NULL) {
|
|
if (!*ptr)
|
|
continue;
|
|
|
|
token = match_token(ptr, tokens, args);
|
|
switch (token) {
|
|
case Opt_dev_config:
|
|
if (match_strlcpy(udev->dev_config, &args[0],
|
|
TCMU_CONFIG_LEN) == 0) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
|
|
break;
|
|
case Opt_dev_size:
|
|
arg_p = match_strdup(&args[0]);
|
|
if (!arg_p) {
|
|
ret = -ENOMEM;
|
|
break;
|
|
}
|
|
ret = kstrtoul(arg_p, 0, (unsigned long *) &udev->dev_size);
|
|
kfree(arg_p);
|
|
if (ret < 0)
|
|
pr_err("kstrtoul() failed for dev_size=\n");
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
kfree(orig);
|
|
return (!ret) ? count : ret;
|
|
}
|
|
|
|
static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
|
|
{
|
|
struct tcmu_dev *udev = TCMU_DEV(dev);
|
|
ssize_t bl = 0;
|
|
|
|
bl = sprintf(b + bl, "Config: %s ",
|
|
udev->dev_config[0] ? udev->dev_config : "NULL");
|
|
bl += sprintf(b + bl, "Size: %zu\n", udev->dev_size);
|
|
|
|
return bl;
|
|
}
|
|
|
|
static sector_t tcmu_get_blocks(struct se_device *dev)
|
|
{
|
|
struct tcmu_dev *udev = TCMU_DEV(dev);
|
|
|
|
return div_u64(udev->dev_size - dev->dev_attrib.block_size,
|
|
dev->dev_attrib.block_size);
|
|
}
|
|
|
|
static sense_reason_t
|
|
tcmu_execute_rw(struct se_cmd *se_cmd, struct scatterlist *sgl, u32 sgl_nents,
|
|
enum dma_data_direction data_direction)
|
|
{
|
|
int ret;
|
|
|
|
ret = tcmu_queue_cmd(se_cmd);
|
|
|
|
if (ret != 0)
|
|
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
|
|
else
|
|
return TCM_NO_SENSE;
|
|
}
|
|
|
|
static sense_reason_t
|
|
tcmu_pass_op(struct se_cmd *se_cmd)
|
|
{
|
|
int ret = tcmu_queue_cmd(se_cmd);
|
|
|
|
if (ret != 0)
|
|
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
|
|
else
|
|
return TCM_NO_SENSE;
|
|
}
|
|
|
|
static struct sbc_ops tcmu_sbc_ops = {
|
|
.execute_rw = tcmu_execute_rw,
|
|
.execute_sync_cache = tcmu_pass_op,
|
|
.execute_write_same = tcmu_pass_op,
|
|
.execute_write_same_unmap = tcmu_pass_op,
|
|
.execute_unmap = tcmu_pass_op,
|
|
};
|
|
|
|
static sense_reason_t
|
|
tcmu_parse_cdb(struct se_cmd *cmd)
|
|
{
|
|
return sbc_parse_cdb(cmd, &tcmu_sbc_ops);
|
|
}
|
|
|
|
DEF_TB_DEFAULT_ATTRIBS(tcmu);
|
|
|
|
static struct configfs_attribute *tcmu_backend_dev_attrs[] = {
|
|
&tcmu_dev_attrib_emulate_model_alias.attr,
|
|
&tcmu_dev_attrib_emulate_dpo.attr,
|
|
&tcmu_dev_attrib_emulate_fua_write.attr,
|
|
&tcmu_dev_attrib_emulate_fua_read.attr,
|
|
&tcmu_dev_attrib_emulate_write_cache.attr,
|
|
&tcmu_dev_attrib_emulate_ua_intlck_ctrl.attr,
|
|
&tcmu_dev_attrib_emulate_tas.attr,
|
|
&tcmu_dev_attrib_emulate_tpu.attr,
|
|
&tcmu_dev_attrib_emulate_tpws.attr,
|
|
&tcmu_dev_attrib_emulate_caw.attr,
|
|
&tcmu_dev_attrib_emulate_3pc.attr,
|
|
&tcmu_dev_attrib_pi_prot_type.attr,
|
|
&tcmu_dev_attrib_hw_pi_prot_type.attr,
|
|
&tcmu_dev_attrib_pi_prot_format.attr,
|
|
&tcmu_dev_attrib_enforce_pr_isids.attr,
|
|
&tcmu_dev_attrib_is_nonrot.attr,
|
|
&tcmu_dev_attrib_emulate_rest_reord.attr,
|
|
&tcmu_dev_attrib_force_pr_aptpl.attr,
|
|
&tcmu_dev_attrib_hw_block_size.attr,
|
|
&tcmu_dev_attrib_block_size.attr,
|
|
&tcmu_dev_attrib_hw_max_sectors.attr,
|
|
&tcmu_dev_attrib_optimal_sectors.attr,
|
|
&tcmu_dev_attrib_hw_queue_depth.attr,
|
|
&tcmu_dev_attrib_queue_depth.attr,
|
|
&tcmu_dev_attrib_max_unmap_lba_count.attr,
|
|
&tcmu_dev_attrib_max_unmap_block_desc_count.attr,
|
|
&tcmu_dev_attrib_unmap_granularity.attr,
|
|
&tcmu_dev_attrib_unmap_granularity_alignment.attr,
|
|
&tcmu_dev_attrib_max_write_same_len.attr,
|
|
NULL,
|
|
};
|
|
|
|
static struct se_subsystem_api tcmu_template = {
|
|
.name = "user",
|
|
.inquiry_prod = "USER",
|
|
.inquiry_rev = TCMU_VERSION,
|
|
.owner = THIS_MODULE,
|
|
.transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
|
|
.attach_hba = tcmu_attach_hba,
|
|
.detach_hba = tcmu_detach_hba,
|
|
.alloc_device = tcmu_alloc_device,
|
|
.configure_device = tcmu_configure_device,
|
|
.free_device = tcmu_free_device,
|
|
.parse_cdb = tcmu_parse_cdb,
|
|
.set_configfs_dev_params = tcmu_set_configfs_dev_params,
|
|
.show_configfs_dev_params = tcmu_show_configfs_dev_params,
|
|
.get_device_type = sbc_get_device_type,
|
|
.get_blocks = tcmu_get_blocks,
|
|
};
|
|
|
|
static int __init tcmu_module_init(void)
|
|
{
|
|
struct target_backend_cits *tbc = &tcmu_template.tb_cits;
|
|
int ret;
|
|
|
|
BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
|
|
|
|
tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
|
|
sizeof(struct tcmu_cmd),
|
|
__alignof__(struct tcmu_cmd),
|
|
0, NULL);
|
|
if (!tcmu_cmd_cache)
|
|
return -ENOMEM;
|
|
|
|
tcmu_root_device = root_device_register("tcm_user");
|
|
if (IS_ERR(tcmu_root_device)) {
|
|
ret = PTR_ERR(tcmu_root_device);
|
|
goto out_free_cache;
|
|
}
|
|
|
|
ret = genl_register_family(&tcmu_genl_family);
|
|
if (ret < 0) {
|
|
goto out_unreg_device;
|
|
}
|
|
|
|
target_core_setup_sub_cits(&tcmu_template);
|
|
tbc->tb_dev_attrib_cit.ct_attrs = tcmu_backend_dev_attrs;
|
|
|
|
ret = transport_subsystem_register(&tcmu_template);
|
|
if (ret)
|
|
goto out_unreg_genl;
|
|
|
|
return 0;
|
|
|
|
out_unreg_genl:
|
|
genl_unregister_family(&tcmu_genl_family);
|
|
out_unreg_device:
|
|
root_device_unregister(tcmu_root_device);
|
|
out_free_cache:
|
|
kmem_cache_destroy(tcmu_cmd_cache);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __exit tcmu_module_exit(void)
|
|
{
|
|
transport_subsystem_release(&tcmu_template);
|
|
genl_unregister_family(&tcmu_genl_family);
|
|
root_device_unregister(tcmu_root_device);
|
|
kmem_cache_destroy(tcmu_cmd_cache);
|
|
}
|
|
|
|
MODULE_DESCRIPTION("TCM USER subsystem plugin");
|
|
MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
|
|
MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(tcmu_module_init);
|
|
module_exit(tcmu_module_exit);
|