SD spec v5.1 adds discard support. The flows and commands are similar to
mmc, so just set the discard arg in CMD38.

A host which supports DISCARD shall check if the DISCARD_SUPPORT (b313)
is set in the SD_STATUS register.  If the card does not support discard,
the host shall not issue DISCARD command, but ERASE command instead.

Post the DISCARD operation, the card may de-allocate the discarded
blocks partially or completely. So the host mustn't make any assumptions
concerning the content of the discarded region. This is unlike ERASE
command, in which the region is guaranteed to contain either '0's or
'1's, depends on the content of DATA_STAT_AFTER_ERASE (b55) in the scr
register.

One more important difference compared to ERASE is the busy timeout
which we will address on the next patch.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

The only left user of mmc_regulator_get_ocrmask() is the mmc core itself.
Therefore, let's drop the export and turn it into static.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

The mmc regulator helper functions, are placed in the extensive core.c
file.  In a step towards trying to create a better structure of files,
avoiding too many lines of code per file, let's move these helpers to a new
file, regulator.c.

Moreover, this within this context it makes sense to also drop the export
of mmc_vddrange_to_ocrmask(), but instead let's make it internal to the mmc
core.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

SD specs version 4.x and 5.x have a dedicated slices in the SCR register.
Higher versions will rely on a combination of the existing fields.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

In MMC, the discard arg is a read-only ext_csd parameter - set it once
on card init. To be consistent, do that for SD as well even though its
discard arg is always 0x0.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

The argument "override_active_level" made it possible to
enforce a specific polarity on the write-protect
GPIO line. All callers in the kernel pass "false" to this
call after I have converted all drivers to use GPIO machine
descriptors, so remove the argument and clean out this.

This kind of polarity inversion should be handled by the
GPIO descriptor inside the GPIO library if needed.

This rids us of one instance of the kludgy calls into
the gpiod_get_raw_value() API.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

The BCM2835 MMC host driver uses a pointer to get from the private
bcm2835_host structure to the generic mmc_host structure.  However the
latter is always immediately preceding the former in memory, so compute
its address with a subtraction (which is cheaper than a dereference) and
drop the superfluous pointer.

No functional change intended.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Frank Pavlic <f.pavlic@kunbus.de>
Cc: Alexander Graf <agraf@suse.de>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

The kblockd workqueue is created with the WQ_MEM_RECLAIM flag set.
This generates a rescuer thread for that queue that will trigger when
the CPU is under heavy load and collect the uncompleted work.

In the case of mmc, this creates the possibility of a deadlock when
there are multiple partitions on the device as other blk-mq work is
also run on the same queue. For example:

- worker 0 claims the mmc host to work on partition 1
- worker 1 attempts to claim the host for partition 2 but has to wait
  for worker 0 to finish
- worker 0 schedules complete_work to release the host
- rescuer thread is triggered after time-out and collects the dangling
  work
- rescuer thread attempts to complete the work in order starting with
  claim host
- the task to release host is now blocked by a task to claim it and
  will never be called

The above results in multiple hung tasks that lead to failures to
mount partitions.

Handling complete_work on a separate workqueue avoids this by keeping
the work completion tasks separate from the other blk-mq work. This
allows the host to be released without getting blocked by other tasks
attempting to claim the host.

Signed-off-by: Zachary Hays <zhays@lexmark.com>
Fixes: 81196976ed94 ("mmc: block: Add blk-mq support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Pull MMC updates from Ulf Hansson:
 "This time, this pull request contains changes crossing subsystems and
  archs/platforms, which is mainly because of a bigger modernization of
  moving from legacy GPIO to GPIO descriptors for MMC (by Linus
  Walleij).

  Additionally, once again, I am funneling changes to
  drivers/misc/cardreader/* and drivers/memstick/* through my MMC tree,
  mostly due to that we lack a maintainer for these.

  Summary:

  MMC core:
   - Cleanup BKOPS support
   - Introduce MMC_CAP_SYNC_RUNTIME_PM
   - slot-gpio: Delete legacy slot GPIO handling

  MMC host:
   - alcor: Add new mmc host driver for Alcor Micro PCI based cardreader
   - bcm2835: Several improvements to better recover from errors
   - jz4740: Rework and fixup pre|post_req support
   - mediatek: Add support for SDIO IRQs
   - meson-gx: Improve clock phase management
   - meson-gx: Stop descriptor on errors
   - mmci: Complete the sbc error path by sending a stop command
   - renesas_sdhi/tmio: Fixup reset/resume operations
   - renesas_sdhi: Add support for r8a774c0 and R7S9210
   - renesas_sdhi: Whitelist R8A77990 SDHI
   - renesas_sdhi: Fixup eMMC HS400 compatibility issues for H3 and M3-W
   - rtsx_usb_sdmmc: Re-work card detection/removal support
   - rtsx_usb_sdmmc: Re-work runtime PM support
   - sdhci: Fix timeout loops for some variant drivers
   - sdhci: Improve support for error handling due to failing commands
   - sdhci-acpi/pci: Disable LED control for Intel BYT-based controllers
   - sdhci_am654: Add new SDHCI variant driver to support TI's AM654 SOCs
   - sdhci-of-esdhc: Add support for eMMC HS400 mode
   - sdhci-omap: Fixup reset support
   - sdhci-omap: Workaround errata regarding SDR104/HS200 tuning failures
   - sdhci-msm: Fixup sporadic write transfers issues for SDR104/HS200
   - sdhci-msm: Fixup dynamical clock gating issues
   - various: Complete converting all hosts into using slot GPIO descriptors

  Other:
   - Move GPIO mmc platform data for mips/sh/arm to GPIO descriptors
   - Add new Alcor Micro cardreader PCI driver
   - Support runtime power management for memstick rtsx_usb_ms driver
   - Use USB remote wakeups for card detection for rtsx_usb misc driver"

* tag 'mmc-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (99 commits)
  mmc: mediatek: Add MMC_CAP_SDIO_IRQ support
  mmc: renesas_sdhi_internal_dmac: Whitelist r8a774c0
  dt-bindings: mmc: renesas_sdhi: Add r8a774c0 support
  mmc: core: Cleanup BKOPS support
  mmc: core: Drop redundant check in mmc_send_hpi_cmd()
  mmc: sdhci-omap: Workaround errata regarding SDR104/HS200 tuning failures (i929)
  dt-bindings: sdhci-omap: Add note for cpu_thermal
  mmc: sdhci-acpi: Disable LED control for Intel BYT-based controllers
  mmc: sdhci-pci: Disable LED control for Intel BYT-based controllers
  mmc: sdhci: Add quirk to disable LED control
  mmc: mmci: add variant property to set command stop bit
  misc: alcor_pci: fix spelling mistake "invailid" -> "invalid"
  mmc: meson-gx: add signal resampling
  mmc: meson-gx: align default phase on soc vendor tree
  mmc: meson-gx: remove useless lock
  mmc: meson-gx: make sure the descriptor is stopped on errors
  mmc: sdhci_am654: Add Initial Support for AM654 SDHCI driver
  dt-bindings: mmc: sdhci-of-arasan: Add deprecated message for AM65
  dt-bindings: mmc: sdhci-am654: Document bindings for the host controllers on TI's AM654 SOCs
  mmc: sdhci-msm: avoid unused function warning
  ...

To allow mmc host drivers to inform the mmc core about rather using
pm_runtime_put_sync_suspend() instead of pm_runtime_put_autosuspend(),
let's introduce MMC_CAP_SYNC_RUNTIME_PM.

This is especially useful for those mmc host drivers that don't benefit
from using the runtime PM autosuspend feature. Typically this is those that
relies on parent devices to power the card via runtime PM, like some USB
host drivers for example.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>