UFS driver can receive a request during memory reclaim by kswapd.  So
when ufs driver puts the ungate work in queue, and if there are no idle
workers, kthreadd is invoked to create a new kworker. Since kswapd task
holds a mutex which kthreadd also needs, this can cause a deadlock
situation. So ungate work must be done in a separate work queue with
WQ_MEM_RECLAIM flag enabled.  Such a workqueue will have a rescue thread
which will be called when the above deadlock condition is possible.
Signed-off-by: NVijay Viswanath <vviswana@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NAsutosh Das <asutoshd@codeaurora.org>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

As multiple requests are submitted to the ufs host controller in
parallel there could be instances where the command completion interrupt
arrives later for a request that is already processed earlier as the
corresponding doorbell was cleared when handling the previous
interrupt. Read the interrupt status in a loop after processing the
received interrupt to catch such interrupts and handle it.
Signed-off-by: NVenkat Gopalakrishnan <venkatg@codeaurora.org>
Signed-off-by: NAsutosh Das <asutoshd@codeaurora.org>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently we call the scsi_block_requests()/scsi_unblock_requests()
whenever we want to block/unblock scsi requests but as there is no
reference counting, nesting of these calls could leave us in undesired
state sometime. Consider following call flow sequence:

1. func1() calls scsi_block_requests() but calls func2() before
   calling scsi_unblock_requests()
2. func2() calls scsi_block_requests()
3. func2() calls scsi_unblock_requests()
4. func1() calls scsi_unblock_requests()

As there is no reference counting, we will have scsi requests unblocked
after #3 instead of it to be unblocked only after #4. Though we may not
have failures seen with this, we might run into some failures in future.
Better solution would be to fix this by adding reference counting.
Signed-off-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Vendor specific setup_clocks ops may depend on clocks managed by ufshcd
driver so if the vendor specific setup_clocks callback is called when
the required clocks are turned off, it results into unclocked register
access.

This change make sure that required clocks are enabled before vendor
specific setup_clocks callback is called.
Signed-off-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NVenkat Gopalakrishnan <venkatg@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The device can set the exception event bit in one of the response UPIU,
for example to notify the need for urgent BKOPs operation.  In such a
case, the host driver calls ufshcd_exception_event_handler to handle
this notification.  When trying to check the exception event status (for
finding the cause for the exception event), the device may be busy with
additional SCSI commands handling and may not respond within the 100ms
timeout.

To prevent that, we need to block SCSI commands during handling of
exception events and allow retransmissions of the query requests, in
case of timeout.
Signed-off-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMaya Erez <merez@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NAsutosh Das <asutoshd@codeaurora.org>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

devfreq requires that the client operates on actual frequencies, not only 0
and UMAX_INT and as such UFS brok with the introduction of f1d981ea ("PM
/ devfreq: Use the available min/max frequency").

This patch registers the frequencies of the first clock with devfreq and use
these to determine if we're trying to step up or down.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> [for devfreq & OPP part]
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Failing to register with devfreq leaves hba->devfreq assigned, which causes
the error path to dereference the ERR_PTR(). Rather than bolting on more
conditionals, move the call of devm_devfreq_add_device() into it's own
function and only update hba->devfreq once it's successfully registered.

The subsequent patch builds upon this to make UFS actually work again, as
it's been broken since f1d981ea ("PM / devfreq: Use the available
min/max frequency")

Also switch to use DEVFREQ_GOV_SIMPLE_ONDEMAND constant.
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This makes ufshcd_config_pwr_mode non-static so that other vendors like
exynos can use it.
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some host controllers don't support host controller enable via HCE.
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
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.
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

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

[mkp: typo]
Signed-off-by: NSeungwon Jeon <essuuj@gmail.com>
Signed-off-by: NAlim Akhtar <alim.akhtar@samsung.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: N"Asutosh Das (asd)" <asutoshd@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

On the quest to remove all VLAs from the kernel[1] this moves buffers
off the stack. In the second instance, this collapses two separately
allocated buffers into a single buffer, since they are used
consecutively, which saves 256 bytes (QUERY_DESC_MAX_SIZE + 1) of stack
space.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.comSigned-off-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

UFS host controllers may support an autonomous power management feature
called the Auto-Hibernate Idle Timer. The timer is set to the number of
microseconds of idle time before the UFS host controller will autonomously
put the link into Hibernate state. That will save power at the expense of
increased latency. Any access to the host controller interface registers
will automatically put the link out of Hibernate state. So once configured,
the feature is transparent to the driver.

Expose the Auto-Hibernate Idle Timer value via SysFS to allow users to
choose between power efficiency or lower latency. Set a default value of
150 ms.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NStanislav Nijnikov <stanislav.nijnikov@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Avoid that the kernel-doc tool complains about mismatches between
kernel-doc headers and function definitions. Avoid that errors like the
following are reported when building the UFS driver with W=1:

drivers/scsi/ufs/tc-dwc-g210-pci.c:60: error: Cannot parse struct or union!
drivers/scsi/ufs/tc-dwc-g210-pltfrm.c:26: warning: cannot understand function prototype: 'struct ufs_hba_variant_ops tc_dwc_g210_20bit_pltfm_hba_vops = '
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Cc: Vivek Gautam <vivek.gautam@codeaurora.org>
Cc: Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch introduces a sysfs group entry for the UFS attributes. The
group adds "attributes" folder under the UFS driver sysfs entry
(/sys/bus/platform/drivers/ufshcd/*). The attributes are shown
as hexadecimal numbers. The full information about the attributes could
be found at UFS specifications 2.1.
Signed-off-by: NStanislav Nijnikov <stanislav.nijnikov@wdc.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch introduces a sysfs group entry for the UFS unit descriptor
parameters. The group adds "unit_descriptor" folder under the corresponding
SCSI device sysfs entry (/sys/class/scsi_device/*/device/). The parameters
are shown as hexadecimal numbers. The full information about the parameters
could be found at UFS specifications 2.1.
Signed-off-by: NStanislav Nijnikov <stanislav.nijnikov@wdc.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch introduces a sysfs group entry for the UFS string descriptors.
The group adds "string_descriptors" folder under the UFS driver
sysfs entry (/sys/bus/platform/drivers/ufshcd/*). The folder will contain
5 files that will show string values defined by the UFS spec:
a manufacturer name, a product name, an OEM id, a serial number and a
product revision.  The full information about the string descriptors
could be found at UFS specifications 2.1.
Signed-off-by: NStanislav Nijnikov <stanislav.nijnikov@wdc.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch introduces a sysfs group entry for the UFS health descriptor
parameters. The group adds "health_descriptor" folder under the UFS driver
sysfs entry (/sys/bus/platform/drivers/ufshcd/*). The parameters are shown
as hexadecimal numbers. The full information about the parameters could be
found at UFS specifications 2.1.
Signed-off-by: NStanislav Nijnikov <stanislav.nijnikov@wdc.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch introduces a sysfs group entry for the UFS device descriptor
parameters. The group adds "device_descriptor" folder under the UFS driver
sysfs entry (/sys/bus/platform/drivers/ufshcd/*). The parameters are shown
as hexadecimal numbers. The full information about the parameters could be
found at UFS specifications 2.1.
Signed-off-by: NStanislav Nijnikov <stanislav.nijnikov@wdc.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch introduces attribute group to show existing sysfs entries.
Signed-off-by: NStanislav Nijnikov <stanislav.nijnikov@wdc.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

WRITE_SAME command is not supported by UFS. Enable a quirk for the upper
level drivers to not send WRITE SAME command.

[mkp: botched patch, applied by hand]
Signed-off-by: NSujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

_vreg_ is being dereferenced before it is null checked, hence there is a
potential null pointer dereference.

Fix this by moving the pointer dereference after _vreg_ has been null
checked.

This issue was detected with the help of Coccinelle.

Fixes: aa497613 ("ufs: Add regulator enable support")
Signed-off-by: NGustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Since the command type of UTRD in UFS 2.1 specification is the same with
UFS 2.0. And it assumes the future UFS specification will follow the
same definition.
Signed-off-by: Nkehuanlin <kehuanlin@pinecone.net>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Several configurable fields of the Device Descriptor and the Unit
Descriptors determine the Boot LUN status. The bBootEnable field and the
bBootLunEn attribute is set to zero by default, so the Boot LUN is
disabled by default.

At which point the scsi device add for Boot LUN will fail, but we can
continue to use the ufs device in fact. This failure shouldn't abort the
device boot.
Signed-off-by: NHuanlin Ke <kehuanlin@pinecone.net>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: NZang Leigang <zangleigang@hisilicon.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: NZang Leigang <zangleigang@hisilicon.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: NZang Leigang <zangleigang@hisilicon.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Forget a condition: eh_work scheduled but do not start to work.
Signed-off-by: NZang Leigang <zangleigang@hisilicon.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Move the initialization of clocks list head to ufshcd_alloc_host() so
that every driver doesn't have to do it. Remove checks for the list head
being NULL because that is not possible.
Signed-off-by: NSzymon Mielczarek <szymonx.mielczarek@intel.com>
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When reloading module these two attributes aren't cleaned up properly
and they persist causing warnings when trying to load module
again. Additionally they are not recreated properly due to that.
Signed-off-by: NMichał Potomski <michalx.potomski@intel.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

It could be just cmp 0xe instead of >>1 and cmp 0x7, with readable code.
Signed-off-by: NTomohiro Kusumi <tkusumi@tuxera.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

MASK_EE_STATUS added by 66ec6d59 was unused, but it seems to have been
defined to do this.
Signed-off-by: NTomohiro Kusumi <tkusumi@tuxera.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This reverts commit 61e07359.

The patch introduced redundant query retries as we already had such
mechanism provided with _retry functions.  Both ufshcd_read_desc and
ufshcd_read_unit_desc_param functions call ufshcd_query_descriptor_retry
wrapper.
Signed-off-by: NSzymon Mielczarek <szymonx.mielczarek@intel.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Not much reason to use ARRAY_SIZE() when we know it's for a C string.
Signed-off-by: NTomohiro Kusumi <tkusumi@tuxera.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

These flags are no longer needed after 2fbd009b in 2013.
Signed-off-by: NTomohiro Kusumi <tkusumi@tuxera.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Not having () isn't likely to do any harm in this case, but all the
other macros below do have it. Also add "are" in a comment.
Signed-off-by: NTomohiro Kusumi <tkusumi@tuxera.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: NTomohiro Kusumi <tkusumi@tuxera.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

ufshcd driver generally uses bool for is_xxx type things instead of int,
so conform to its style.
Signed-off-by: NTomohiro Kusumi <tkusumi@tuxera.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

These aren't really falling through to anywhere meaningful.
Signed-off-by: NTomohiro Kusumi <tkusumi@tuxera.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

There are same conditions for checking whether supporting clkscaling or
not. When ufshcd is supporting clkscaling, active_reqs should be
decreased by one.

[mkp: addressed comment from Bartlomiej]
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NSubhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>