Commit 5586dd8e ("scsi: ufs: Fix a race condition between error handler
and runtime PM ops") moves the ufshcd_scsi_block_requests() inside
err_handler() but forgets to remove the ufshcd_scsi_unblock_requests() in
the early return path. Correct the mistake.

Link: https://lore.kernel.org/r/1597798958-24322-1-git-send-email-cang@codeaurora.org
Fixes: 5586dd8e ("scsi: ufs: Fix a race condition between error handler and runtime PM ops")
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Hongwu Su<hongwus@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently, the UFS driver busy waits for fDeviceInit to be cleared. Provide
an upper bound and sleep between attempts instead of busy waiting.

Link: https://lore.kernel.org/r/1597053747-75171-1-git-send-email-kwmad.kim@samsung.comTested-by: NKiwoong Kim <kwmad.kim@samsung.com>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NKiwoong Kim <kwmad.kim@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Link: https://lore.kernel.org/r/20200814095034.20709-3-huobean@gmail.comReviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

ufshcd_comp_devman_upiu() was poorly named leading people to think it was a
completion function. Rename it to ufshcd_compose_devman_upiu().

Link: https://lore.kernel.org/r/20200814095034.20709-2-huobean@gmail.comReviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Acked-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

In current UFS task abort hook, namely ufshcd_abort(), if one task is
aborted successfully, clk_gating.active_reqs held by this task is not
decreased, which makes clk_gating.active_reqs stay above zero forever, thus
clock gating would never happen. Instead of releasing resources of one task
"manually", use the existing func __ufshcd_transfer_req_compl().  This
change also eliminates a possible race of scsi_dma_unmap() from the real
completion in IRQ handler path.

Link: https://lore.kernel.org/r/1596975355-39813-10-git-send-email-cang@codeaurora.org
Fixes: 1ab27c9c ("ufs: Add support for clock gating")
CC: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The current IRQ handler blocks SCSI requests before scheduling eh_work,
when error handler calls pm_runtime_get_sync, if ufshcd_suspend/resume
sends a SCSI cmd, most likely the SSU cmd, since SCSI requests are blocked,
pm_runtime_get_sync() will never return because ufshcd_suspend/resume is
blocked by the SCSI cmd.

 - In queuecommand path, hba->ufshcd_state check and ufshcd_send_command
   should stay under the same spin lock. This is to make sure that no more
   commands leak into doorbell after hba->ufshcd_state is changed.

 - Don't block SCSI requests before error handler starts to run, let error
   handler block SCSI requests when it is ready to start error recovery.

 - Don't let SCSI layer keep requeuing the SCSI cmds sent from HBA runtime
   PM ops, let them pass or fail them. Let them pass if eh_work is
   scheduled due to non-fatal errors. Fail them if eh_work is scheduled due
   to fatal errors, otherwise the cmds may eventually time out since UFS is
   in bad state, which gets error handler blocked for too long. If we fail
   the SCSI cmds sent from HBA runtime PM ops, HBA runtime PM ops fails
   too, but it does not hurt since error handler can recover HBA runtime PM
   error.

Link: https://lore.kernel.org/r/1596975355-39813-9-git-send-email-cang@codeaurora.orgReviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Performing dumps in the IRQ handler causes system stability issues. Move
dumps to the error handler and only print basic host registers here.

Link: https://lore.kernel.org/r/1596975355-39813-8-git-send-email-cang@codeaurora.orgReviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The current error handler can not recover HBA runtime PM error if
ufshcd_suspend/resume has failed due to UFS errors, e.g. hibern8 enter/exit
error or SSU cmd error. When this happens, error handler may fail
performing a full reset and restore because error handler always assumes
that power, IRQs and clocks are ready after pm_runtime_get_sync returns,
but actually they are not if ufshcd_resume fails[1].

If ufschd_suspend/resume fails due to UFS errors, runtime PM framework
saves the error value to dev.power.runtime_error. After that, HBA dev
runtime suspend/resume would not be invoked anymore unless runtime_error is
cleared[2].

In case of ufshcd_suspend/resume fails due to UFS errors, for scenario [1],
error handler cannot assume anything of pm_runtime_get_sync, meaning error
handler should explicitly turn ON powers, IRQs and clocks again. To get the
HBA runtime PM work as regard for scenario [2], error handler can clear the
runtime_error by calling pm_runtime_set_active() if full reset and restore
succeeds. And, more important, if pm_runtime_set_active() returns no error,
which means runtime_error has been cleared, we also need to resume those
scsi devices under HBA in case any of them has failed to be resumed due to
HBA runtime resume failure. This is to unblock blk_queue_enter in case
there are bios waiting inside it.

Link: https://lore.kernel.org/r/1596975355-39813-7-git-send-email-cang@codeaurora.orgReviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Error recovery can be invoked from multiple code paths, including hibern8
enter/exit (from ufshcd_link_recovery), ufshcd_eh_host_reset_handler() and
eh_work scheduled from IRQ context. Ultimately, these paths are all trying
to invoke ufshcd_reset_and_restore() in either a synchronous or
asynchronous manner. This causes problems:

 - If link recovery happens during ungate work, ufshcd_hold() would be
   called recursively. Although commit 53c12d0e ("scsi: ufs: fix error
   recovery after the hibern8 exit failure") fixed a deadlock due to
   recursive calls of ufshcd_hold() by adding a check of eh_in_progress
   into ufshcd_hold, this check allows eh_work to run in parallel while
   link recovery is running.

 - Similar concurrency can also happen when error recovery is invoked from
   ufshcd_eh_host_reset_handler and ufshcd_link_recovery.

 - Concurrency can even happen between eh_works. eh_work, currently queued
   on system_wq, is allowed to have multiple instances running in parallel,
   but we don't have proper protection for that.

If any of above concurrency scenarios happen, error recovery would fail and
lead ufs device and host into bad states. To fix the concurrency problem,
this change queues eh_work on a single threaded workqueue and removes link
recovery calls from the hibern8 enter/exit path. In addition, make use of
eh_work in eh_host_reset_handler instead of calling
ufshcd_reset_and_restore. This unifies the UFS error recovery mechanism.

According to the UFSHCI JEDEC spec, hibern8 enter/exit error occurs when
the link is broken. This essentially applies to any power mode change
operations (since they all use PACP_PWR cmds in UniPro layer). So, if a
power mode change operation (including AH8 enter/exit) fails, mark link
state as UIC_LINK_BROKEN_STATE and schedule the eh_work.  In this case,
error handler needs to do a full reset and restore to recover the link back
to active. Before the link state is recovered to active,
ufshcd_uic_pwr_ctrl simply returns -ENOLINK to avoid more errors.

Link: https://lore.kernel.org/r/1596975355-39813-6-git-send-email-cang@codeaurora.orgReviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Information about the last interrupt status and timestamp is helpful when
debugging system stability issues (IRQ starvation, for instance). Add this
information to ufshcd_print_host_state() output.

In addition, UFS device information such as model name and firmware version
also comes in handy during debugging. This is printed as well.

Link: https://lore.kernel.org/r/1596975355-39813-5-git-send-email-cang@codeaurora.orgReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NHongwu Su <hongwus@codeaurora.org>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Clock gating can be turned on/off selectively which means the associated
state information is only correct if the feature is enabled. This change
makes sure that we only look at state of clk-gating if it is enabled.

Link: https://lore.kernel.org/r/1596975355-39813-2-git-send-email-cang@codeaurora.orgReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NHongwu Su <hongwus@codeaurora.org>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some UFS devices require delay after VCC power rail is turned off.
Introduce a device quirk "DELAY_AFTER_LPM" to add 5ms delay after VCC
power-off during suspend flow.

Link: https://lore.kernel.org/r/20200729051840.31318-2-stanley.chu@mediatek.comReviewed-by: NAndy Teng <andy.teng@mediatek.com>
Reviewed-by: NPeter Wang <peter.wang@mediatek.com>
Reviewed-by: NCan Guo <cang@codeaurora.org>
Acked-by: NAvri Altman <Avri.Altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Add missing setup_xfer_req() call in ufshcd_issue_devman_upiu_cmd() in
ufs-bsg path. Relocate existing setup_xfer_req() calls to a common place,
i.e., ufshcd_send_command(), to simplify the driver.

Link: https://lore.kernel.org/r/20200706060707.32608-3-stanley.chu@mediatek.comAcked-by: NAvri Altman <Avri.Altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Simplify recording command completion time in __ufshcd_transfer_req_compl()
by assigning lrbp->compl_time_stamp in a unified location.

Link: https://lore.kernel.org/r/20200706060707.32608-2-stanley.chu@mediatek.comAcked-by: NAvri Altman <Avri.Altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Wire up ufshcd.c with the UFS Crypto API, the block layer inline encryption
additions and the keyslot manager.

Many existing inline crypto devices require some additional behaviour not
specified in the UFSHCI v2.1 specification - as such the vendor specific
drivers will need to be updated where necessary to make it possible to use
those devices. Some of these changes have already been proposed upstream,
such as for the Qualcomm 845 SoC at
https://lkml.kernel.org/linux-scsi/20200501045111.665881-1-ebiggers@kernel.org/
and for ufs-mediatek at
https://lkml.kernel.org/linux-scsi/20200304022101.14165-1-stanley.chu@mediatek.com/

This patch has been tested on the db845c, sm8150-mtp and sm8250-mtp
(which have Qualcomm chipsets) and on some mediatek chipsets using these
aforementioned vendor specific driver updates.

Link: https://lore.kernel.org/r/20200706200414.2027450-4-satyat@google.comReviewed-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NSatya Tangirala <satyat@google.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Add the crypto registers and structs defined in v2.1 of the JEDEC UFSHCI
specification in preparation to add support for inline encryption to UFS.

Link: https://lore.kernel.org/r/20200706200414.2027450-2-satyat@google.comReviewed-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NSatya Tangirala <satyat@google.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

According to the UFS Spec, the Flags field in the UPIU is one byte in size,
not 4. Change it to be u8.

Link: https://lore.kernel.org/r/20200706123936.24799-1-huobean@gmail.comTested-by: NAlim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

If a UFS device is not qualified to use WriteBooster, either due to wrong
UFS version or device-specific quirks, then the capability in host shall be
disabled to prevent any WriteBooster operations in the future.

Link: https://lore.kernel.org/r/20200625030430.25048-1-stanley.chu@mediatek.com
Fixes: 3d17b9b5 ("scsi: ufs: Add write booster feature support")
Tested-by: NSteev Klimaszewski <steev@kali.org>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The UFS load calculation is based on "total_time" and "busy_time" in a
devfreq window.  However, the source of time is different for both
parameters: "busy_time" is assigned from "jiffies" thus has different
accuracy from "total_time" which is assigned from ktime_get().

In addition, the time of window boundary is not exactly the same as the
starting busy time in this window if UFS is actually busy in the beginning
of the window. A similar accuracy error may also happen for the end of busy
time in current window.

To guarantee the precision of load calculation, we need to

1. Align time accuracy of both devfreq_dev_status.total_time and
   devfreq_dev_status.busy_time. For example, use "ktime_get()" directly.

2. Align the following timelines:
   - The beginning time of devfreq windows
   - The beginning of busy time in a new window
   - The end of busy time in the current window

Link: https://lore.kernel.org/r/20200611101043.6379-1-stanley.chu@mediatek.com
Fixes: a3cd5ec5 ("scsi: ufs: add load based scaling of UFS gear")
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Use the ftrace infrastructure to conditionally trace UFS UIC command
events.

New trace event "ufshcd_uic_command" is created, which samples the
following UFS UIC command data:

 - Device name
 - Optional identification string
 - UIC command opcode
 - UIC command argument1
 - UIC command argument2
 - UIC command argement3

Usage:
	echo 1 > /sys/kernel/debug/tracing/events/ufs/enable
	cat /sys/kernel/debug/tracing/trace_pipe

Link: https://lore.kernel.org/r/20200615072235.23042-3-stanley.chu@mediatek.comAcked-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Clean up the following items:

 - Sort vendor names in alphabetical order

 - Squash quirks as compact as possible in device table to enhance
   performance of the lookup

 - Sort device quirks in alphabetical order

Link: https://lore.kernel.org/r/20200612012625.6615-3-stanley.chu@mediatek.comReviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

It is confirmed that Micron device needs DELAY_BEFORE_LPM quirk to have a
delay before VCC is powered off. Sdd Micron vendor ID and this quirk for
Micron devices.

Link: https://lore.kernel.org/r/20200612012625.6615-2-stanley.chu@mediatek.comReviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Add SPDX GPL-2.0 to UFS driver files that specified the GPL version 2
license, remove the full boilerplate text.

Link: https://lore.kernel.org/r/20200605200520.20831-2-huobean@gmail.comReviewed-by: NTomas Winkler <tomas.winkler@intel.com>
Reviewed-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For UFS 3.1, the normal unit descriptor is 10 bytes larger than the RPMB
unit. However, both descriptors share the same desc_idn, to cover both unit
descriptors with one length, we choose the normal unit descriptor length by
desc_index.

Link: https://lore.kernel.org/r/20200603091959.27618-6-huobean@gmail.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

At UFS initialization stage, to get the length of the descriptor,
ufshcd_read_desc_length() was being called 6 times. Instead, we will
capture the descriptor size the first time we'll read it.

Delete unnecessary redundant code, remove ufshcd_read_desc_length(),
ufshcd_init_desc_sizes(), and boost UFS initialization.

Link: https://lore.kernel.org/r/20200603091959.27618-5-huobean@gmail.comAcked-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NBart van Assche <bvanassche@acm.org>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

If param_offset is not 0, the memcpy length shouldn't be the true
descriptor length.

Link: https://lore.kernel.org/r/20200603091959.27618-4-huobean@gmail.comAcked-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Delete ufshcd_read_desc(). Instead, let caller directly call
ufshcd_read_desc_param().

Link: https://lore.kernel.org/r/20200603091959.27618-3-huobean@gmail.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NBart van Assche <bvanassche@acm.org>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For the UFS device, the maximum descriptor size is 255, max_t called on
ufs_get_device_desc() is useless.

Link: https://lore.kernel.org/r/20200603091959.27618-2-huobean@gmail.comReviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Acked-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NBart van Assche <bvanassche@acm.org>
Signed-off-by: NBean Huo <beanhuo@micron.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some controller like Exynos determines if FATAL ERROR (0x7) in OCS field in
UTRD occurs for values other than GOOD (0x0) in STATUS field in response
upiu as well as errors that a host controller can't cover.  This patch is
to prevent from reporting command results in those cases.

Link: https://lore.kernel.org/r/20200528011658.71590-6-alim.akhtar@samsung.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NKiwoong Kim <kwmad.kim@samsung.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some UFS host controllers like Exynos uses granularities of PRDT length and
offset as bytes, whereas others use actual segment count.

Link: https://lore.kernel.org/r/20200528011658.71590-5-alim.akhtar@samsung.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NKiwoong Kim <kwmad.kim@samsung.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some host controllers don't support host controller enable via HCE.

Link: https://lore.kernel.org/r/20200528011658.71590-4-alim.akhtar@samsung.comReviewed-by: NCan Guo <cang@codeaurora.org>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some host controllers support interrupt aggregation but don't allow
resetting counter and timer in software.

Link: https://lore.kernel.org/r/20200528011658.71590-3-alim.akhtar@samsung.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

With the correct behavior, setting the bit to '0' indicates clear and '1'
indicates no change. If host controller handles this the other way around,
UFSHCI_QUIRK_BROKEN_REQ_LIST_CLR can be used.

Link: https://lore.kernel.org/r/20200528011658.71590-2-alim.akhtar@samsung.comReviewed-by: NCan Guo <cang@codeaurora.org>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

In ufshcd_probe_hba(), all BKOP SW tracking variables can be reset together
in ufshcd_force_reset_auto_bkops(), thus urgent_bkop_lvl initialization in
the beginning of ufshcd_probe_hba() can be merged into
ufshcd_force_reset_auto_bkops().

Link: https://lore.kernel.org/r/20200530141200.4616-1-stanley.chu@mediatek.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Urgent bkops level is used to compare against actual bkops status read from
UFS device. Urgent bkops level is set during initialization and might be
updated in exception event handler during runtime. But it should not be
updated to the actual bkops status every time when auto bkops is toggled.
Otherwise, if urgent bkops level is updated to 0, auto bkops shall always
be kept enabled.

Link: https://lore.kernel.org/r/1590632686-17866-1-git-send-email-cang@codeaurora.org
Fixes: 24366c2a ("scsi: ufs: Recheck bkops level if bkops is disabled")
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently UFS host driver promises VCC supply if UFS device needs to do
WriteBooster flush during runtime suspend.

However the UFS specification mentions:

"While the flushing operation is in progress, the device is in Active power
mode."

Therefore UFS host driver needs to promise more: Keep UFS device as "Active
power mode", otherwise UFS device shall not do any flush if device enters
Sleep or PowerDown power mode.  Similarly, the same promises shall be
applied if device needs urgent BKOP during runtime suspend.

Fix this by not changing device power mode if WriteBooster flush or urgent
BKOP is required in ufshcd_suspend().

Now, if device finishes its job but is not resumed for a very long time,
system will have unnecessary power drain because VCC is still supplied. A
method to re-check the threshold of keeping VCC supply is required to fix
the power drain. However, the threshold re-check needs to re-activate the
link first because the decision depends on the latest device status.

Also introduce a delayed work to force runtime resume after a certain delay
during runtime suspend. This makes threshold re-check happen natually in
the entry of the next runtime-suspend. The device can continue its
WriteBooster flush or urgent BKOP jobs soon after resumed if device has no
upcoming requests and link enters hibern8 state either by Auto-Hibern8 or
hibern8 during clk-gating scheme. This solution not only prevents power
drain but also makes as much use of time as possible for device's
background jobs.

Link: https://lore.kernel.org/r/20200522083212.4008-5-stanley.chu@mediatek.comReviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For WriteBooster feature related attributes, the index used by query shall
be LUN ID if LU Dedicated buffer mode is enabled.

Link: https://lore.kernel.org/r/20200522083212.4008-4-stanley.chu@mediatek.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

According to the UFS specification, WriteBooster is officially supported by
UFS 2.2.

Since UFS 2.2 specification has been finalized in JEDEC and such devices
have also showed up in the market, modify the checking rule for
ufshcd_wb_probe() to allow these devices to enable WriteBooster.

Link: https://lore.kernel.org/r/20200522083212.4008-3-stanley.chu@mediatek.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The whole UFS host instance has been zero-initialized by scsi_host_alloc(),
thus UFS driver does not need to clear "dev_info" member specifically in
ufshcd_device_params_init().

Simply remove the unnecessary code.

Link: https://lore.kernel.org/r/20200522083212.4008-2-stanley.chu@mediatek.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The ufshcd_wait_for_register() function either sleeps or spins until the
specified register has reached the desired value. Busy-waiting is not only
considered a bad practice but also has a bad impact on energy
consumption. Always sleep instead of spinning by making sure that all
ufshcd_wait_for_register() calls happen from a context where it is allowed
to sleep. The only function call that has to be moved is the
ufshcd_hba_stop() call in ufshcd_host_reset_and_restore().

Link: https://lore.kernel.org/r/20200507222750.19113-1-bvanassche@acm.org
Cc: Can Guo <cang@codeaurora.org>
Cc: Avri Altman <avri.altman@wdc.com>
Cc: Bean Huo <beanhuo@micron.com>
Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Asutosh Das <asutoshd@codeaurora.org>
Tested-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>