There is a lock inversion and rwsem read-lock recursion in the devfreq
target callback which can lead to deadlocks.

Specifically, ufshcd_devfreq_scale() already holds a clk_scaling_lock
read lock when toggling the write booster, which involves taking the
dev_cmd mutex before taking another clk_scaling_lock read lock.

This can lead to a deadlock if another thread:

  1) tries to acquire the dev_cmd and clk_scaling locks in the correct
     order, or

  2) takes a clk_scaling write lock before the attempt to take the
     clk_scaling read lock a second time.

Fix this by dropping the clk_scaling_lock before toggling the write booster
as was done before commit 0e9d4ca43ba8 ("scsi: ufs: Protect some contexts
from unexpected clock scaling").

While the devfreq callbacks are already serialised, add a second
serialising mutex to handle the unlikely case where a callback triggered
through the devfreq sysfs interface is racing with a request to disable
clock scaling through the UFS controller 'clkscale_enable' sysfs
attribute. This could otherwise lead to the write booster being left
disabled after having disabled clock scaling.

Also take the new mutex in ufshcd_clk_scaling_allow() to make sure that any
pending write booster update has completed on return.

Note that this currently only affects Qualcomm platforms since commit
87bd05016a64 ("scsi: ufs: core: Allow host driver to disable wb toggling
during clock scaling").

The lock inversion (i.e. 1 above) was reported by lockdep as:

 ======================================================
 WARNING: possible circular locking dependency detected
 6.1.0-next-20221216 #211 Not tainted
 ------------------------------------------------------
 kworker/u16:2/71 is trying to acquire lock:
 ffff076280ba98a0 (&hba->dev_cmd.lock){+.+.}-{3:3}, at: ufshcd_query_flag+0x50/0x1c0

 but task is already holding lock:
 ffff076280ba9cf0 (&hba->clk_scaling_lock){++++}-{3:3}, at: ufshcd_devfreq_scale+0x2b8/0x380

 which lock already depends on the new lock.
[  +0.011606]
 the existing dependency chain (in reverse order) is:

 -> #1 (&hba->clk_scaling_lock){++++}-{3:3}:
        lock_acquire+0x68/0x90
        down_read+0x58/0x80
        ufshcd_exec_dev_cmd+0x70/0x2c0
        ufshcd_verify_dev_init+0x68/0x170
        ufshcd_probe_hba+0x398/0x1180
        ufshcd_async_scan+0x30/0x320
        async_run_entry_fn+0x34/0x150
        process_one_work+0x288/0x6c0
        worker_thread+0x74/0x450
        kthread+0x118/0x120
        ret_from_fork+0x10/0x20

 -> #0 (&hba->dev_cmd.lock){+.+.}-{3:3}:
        __lock_acquire+0x12a0/0x2240
        lock_acquire.part.0+0xcc/0x220
        lock_acquire+0x68/0x90
        __mutex_lock+0x98/0x430
        mutex_lock_nested+0x2c/0x40
        ufshcd_query_flag+0x50/0x1c0
        ufshcd_query_flag_retry+0x64/0x100
        ufshcd_wb_toggle+0x5c/0x120
        ufshcd_devfreq_scale+0x2c4/0x380
        ufshcd_devfreq_target+0xf4/0x230
        devfreq_set_target+0x84/0x2f0
        devfreq_update_target+0xc4/0xf0
        devfreq_monitor+0x38/0x1f0
        process_one_work+0x288/0x6c0
        worker_thread+0x74/0x450
        kthread+0x118/0x120
        ret_from_fork+0x10/0x20

 other info that might help us debug this:
  Possible unsafe locking scenario:
        CPU0                    CPU1
        ----                    ----
   lock(&hba->clk_scaling_lock);
                                lock(&hba->dev_cmd.lock);
                                lock(&hba->clk_scaling_lock);
   lock(&hba->dev_cmd.lock);

  *** DEADLOCK ***

Fixes: 0e9d4ca43ba8 ("scsi: ufs: Protect some contexts from unexpected clock scaling")
Cc: stable@vger.kernel.org      # 5.12
Cc: Can Guo <quic_cang@quicinc.com>
Tested-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230116161201.16923-1-johan+linaro@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Pull in remaining patches from the 6.2 queue.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Pull SCSI updates from James Bottomley:
 "Updates to the usual drivers (target, ufs, smartpqi, lpfc).

  There are some core changes, mostly around reworking some of our user
  context assumptions in device put and moving some code around.

  The remaining updates are bug fixes and minor changes"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (138 commits)
  scsi: sg: Fix get_user() in call sg_scsi_ioctl()
  scsi: megaraid_sas: Fix some spelling mistakes in comment
  scsi: core: Use SCSI_SCAN_INITIAL in do_scsi_scan_host()
  scsi: core: Use SCSI_SCAN_RESCAN in __scsi_add_device()
  scsi: ufs: ufs-mediatek: Remove unnecessary return code
  scsi: ufs: core: Fix the polling implementation
  scsi: libsas: Do not export sas_ata_wait_after_reset()
  scsi: hisi_sas: Fix SATA devices missing issue during I_T nexus reset
  scsi: libsas: Add smp_ata_check_ready_type()
  scsi: Revert "scsi: hisi_sas: Don't send bcast events from HW during nexus HA reset"
  scsi: Revert "scsi: hisi_sas: Drain bcast events in hisi_sas_rescan_topology()"
  scsi: ufs: ufs-mediatek: Modify the return value
  scsi: ufs: ufs-mediatek: Remove unneeded code
  scsi: device_handler: alua: Call scsi_device_put() from non-atomic context
  scsi: device_handler: alua: Revert "Move a scsi_device_put() call out of alua_check_vpd()"
  scsi: snic: Fix possible UAF in snic_tgt_create()
  scsi: qla2xxx: Initialize vha->unknown_atio_[list, work] for NPIV hosts
  scsi: qla2xxx: Remove duplicate of vha->iocb_work initialization
  scsi: fcoe: Fix transport not deattached when fcoe_if_init() fails
  scsi: sd: Use 16-byte SYNCHRONIZE CACHE on ZBC devices
  ...

When SSU/enter hibern8 fail in WLUN suspend flow, trigger the error handler
and return busy to break the suspend.  Otherwise the consumer will get
stuck in runtime suspend status.

Fixes: b294ff3e3449 ("scsi: ufs: core: Enable power management for wlun")
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Link: https://lore.kernel.org/r/20221208072520.26210-1-peter.wang@mediatek.com
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Pull block updates from Jens Axboe:

 - NVMe pull requests via Christoph:
      - Support some passthrough commands without CAP_SYS_ADMIN (Kanchan
        Joshi)
      - Refactor PCIe probing and reset (Christoph Hellwig)
      - Various fabrics authentication fixes and improvements (Sagi
        Grimberg)
      - Avoid fallback to sequential scan due to transient issues (Uday
        Shankar)
      - Implement support for the DEAC bit in Write Zeroes (Christoph
        Hellwig)
      - Allow overriding the IEEE OUI and firmware revision in configfs
        for nvmet (Aleksandr Miloserdov)
      - Force reconnect when number of queue changes in nvmet (Daniel
        Wagner)
      - Minor fixes and improvements (Uros Bizjak, Joel Granados, Sagi
        Grimberg, Christoph Hellwig, Christophe JAILLET)
      - Fix and cleanup nvme-fc req allocation (Chaitanya Kulkarni)
      - Use the common tagset helpers in nvme-pci driver (Christoph
        Hellwig)
      - Cleanup the nvme-pci removal path (Christoph Hellwig)
      - Use kstrtobool() instead of strtobool (Christophe JAILLET)
      - Allow unprivileged passthrough of Identify Controller (Joel
        Granados)
      - Support io stats on the mpath device (Sagi Grimberg)
      - Minor nvmet cleanup (Sagi Grimberg)

 - MD pull requests via Song:
      - Code cleanups (Christoph)
      - Various fixes

 - Floppy pull request from Denis:
      - Fix a memory leak in the init error path (Yuan)

 - Series fixing some batch wakeup issues with sbitmap (Gabriel)

 - Removal of the pktcdvd driver that was deprecated more than 5 years
   ago, and subsequent removal of the devnode callback in struct
   block_device_operations as no users are now left (Greg)

 - Fix for partition read on an exclusively opened bdev (Jan)

 - Series of elevator API cleanups (Jinlong, Christoph)

 - Series of fixes and cleanups for blk-iocost (Kemeng)

 - Series of fixes and cleanups for blk-throttle (Kemeng)

 - Series adding concurrent support for sync queues in BFQ (Yu)

 - Series bringing drbd a bit closer to the out-of-tree maintained
   version (Christian, Joel, Lars, Philipp)

 - Misc drbd fixes (Wang)

 - blk-wbt fixes and tweaks for enable/disable (Yu)

 - Fixes for mq-deadline for zoned devices (Damien)

 - Add support for read-only and offline zones for null_blk
   (Shin'ichiro)

 - Series fixing the delayed holder tracking, as used by DM (Yu,
   Christoph)

 - Series enabling bio alloc caching for IRQ based IO (Pavel)

 - Series enabling userspace peer-to-peer DMA (Logan)

 - BFQ waker fixes (Khazhismel)

 - Series fixing elevator refcount issues (Christoph, Jinlong)

 - Series cleaning up references around queue destruction (Christoph)

 - Series doing quiesce by tagset, enabling cleanups in drivers
   (Christoph, Chao)

 - Series untangling the queue kobject and queue references (Christoph)

 - Misc fixes and cleanups (Bart, David, Dawei, Jinlong, Kemeng, Ye,
   Yang, Waiman, Shin'ichiro, Randy, Pankaj, Christoph)

* tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux: (247 commits)
  blktrace: Fix output non-blktrace event when blk_classic option enabled
  block: sed-opal: Don't include <linux/kernel.h>
  sed-opal: allow using IOC_OPAL_SAVE for locking too
  blk-cgroup: Fix typo in comment
  block: remove bio_set_op_attrs
  nvmet: don't open-code NVME_NS_ATTR_RO enumeration
  nvme-pci: use the tagset alloc/free helpers
  nvme: add the Apple shared tag workaround to nvme_alloc_io_tag_set
  nvme: only set reserved_tags in nvme_alloc_io_tag_set for fabrics controllers
  nvme: consolidate setting the tagset flags
  nvme: pass nr_maps explicitly to nvme_alloc_io_tag_set
  block: bio_copy_data_iter
  nvme-pci: split out a nvme_pci_ctrl_is_dead helper
  nvme-pci: return early on ctrl state mismatch in nvme_reset_work
  nvme-pci: rename nvme_disable_io_queues
  nvme-pci: cleanup nvme_suspend_queue
  nvme-pci: remove nvme_pci_disable
  nvme-pci: remove nvme_disable_admin_queue
  nvme: merge nvme_shutdown_ctrl into nvme_disable_ctrl
  nvme: use nvme_wait_ready in nvme_shutdown_ctrl
  ...

Modify to remove unnecessary 'return 0' code.

Signed-off-by: ChanWoo Lee <cw9316.lee@samsung.com>
Link: https://lore.kernel.org/r/20221121003338.11034-1-cw9316.lee@samsung.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Fix the following issues in ufshcd_poll():

 - If polling succeeds, return a positive value.

 - Do not complete polling requests from interrupt context because the
   block layer expects these requests to be completed from thread
   context. From block/bio.c:

     If REQ_ALLOC_CACHE is set, the final put of the bio MUST be done from
     process context, not hard/soft IRQ.

Fixes: eaab9b573054 ("scsi: ufs: Implement polling support")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221118233717.441298-1-bvanassche@acm.org
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Be consistent with the rest of driver wrt. functions returning bool.

  91: 	return !!(host->caps & UFS_MTK_CAP_BOOST_CRYPT_ENGINE);
  98: 	return !!(host->caps & UFS_MTK_CAP_VA09_PWR_CTRL);
  105:	return !!(host->caps & UFS_MTK_CAP_BROKEN_VCC);

Signed-off-by: ChanWoo Lee <cw9316.lee@samsung.com>
Link: https://lore.kernel.org/r/20221118045242.2770-1-cw9316.lee@samsung.com
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Remove unnecessary if/goto code.

Signed-off-by: ChanWoo Lee <cw9316.lee@samsung.com>
Link: https://lore.kernel.org/r/20221118044136.921-1-cw9316.lee@samsung.com
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Setting bitmap_len is not required when returning early. Defer until it is
needed.

Signed-off-by: ChanWoo Lee <cw9316.lee@samsung.com>
Link: https://lore.kernel.org/r/20221111062301.7423-1-cw9316.lee@samsung.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>