With gcc 4.1.2:

    drivers/mmc/core/block.c: In function ‘mmc_blk_ioctl_cmd_issue’:
    drivers/mmc/core/block.c:630: warning: ‘ioc_err’ may be used uninitialized in this function

Indeed, if mq_rq->ioc_count is zero, an uninitialized value will be
stored in mq_rq->drv_op_result and passed to blk_end_request_all().

Can mq_rq->ioc_count be zero?
  - mmc_blk_ioctl_cmd() sets ioc_count to 1, so this is safe,
  - mmc_blk_ioctl_multi_cmd() obtains ioc_count from user space in
    response to the MMC_IOC_MULTI_CMD ioctl, and does allow zero.

To avoid returning an uninitialized value, and as it is pointless to do
all this work when the MMC_IOC_MULTI_CMD ioctl is used with zero
entries, check for this early in mmc_blk_ioctl_multi_cmd(), and return
zero, like was returned before.

Fixes: 3ecd8cf2 ("mmc: block: move multi-ioctl() to use block layer")
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

With gcc 4.1.2:

    drivers/mmc/core/block.c: In function ‘mmc_blk_issue_drv_op’:
    drivers/mmc/core/block.c:1178: warning: ‘ret’ may be used uninitialized in this function

Indeed, for MMC_DRV_OP_IOCTL, if mq_rq->ioc_count is zero, an
uninitialized value will be stored in mq_rq->drv_op_result and passed to
blk_end_request_all().

Can mq_rq->ioc_count be zero?
  - mmc_blk_ioctl_cmd() sets ioc_count to 1, so this is safe,
  - mmc_blk_ioctl_multi_cmd() obtains ioc_count from user space in
    response to the MMC_IOC_MULTI_CMD ioctl, and does allow zero.

Initialize ret to zero to fix this for current and future callers.

Fixes: 0493f6fe ("mmc: block: Move boot partition locking into a driver op")
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

BLK_BOUNCE_ANY is the defauly now, so the call is superflous.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add host capability MMC_CAP_CD_WAKE to enable irq wake on the card detect
irq.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

The MMC_CAP2_HC_ERASE_SZ is used only by a few mmc host drivers. Its intent
is to enable eMMC's high-capacity erase size, as to improve the behaviour
of the erase operations.

We should strive to avoid software configuration options that aren't
necessary, but instead deploy common behaviours. For these reasons, let's
remove the capability bit for MMC_CAP2_HC_ERASE_SZ and make it the default
behaviour.

Note that this change doesn't affect eMMCs supporting trim/discard, because
these commands operates on sectors and takes precedence over erase
commands.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Tested-by: NShawn Lin <shawn.lin@rock-chips.com>

Some errors are flagged only with the next command after a multiblock
transfer, e.g. ECC error. So, when checking for data transfer errors,
we check the result from the stop command as well.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

To detect errors like ECC errors, we must parse the R1 response bits. Introduce
a helper function to also set the error value of a command when R1 error bits
are set. Add ECC error to list of flags checked. Use the new helper for the
stop command to call mmc_blk_recovery when detecting ECC errors which are only
flagged on the next command after multiblock.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: NYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

To make the code more consistent and to increase readability, add an
mmc_spi_send_csd() function, which gets called from mmc_send_csd() in case
of SPI mode.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>

Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>

Instead of having the caller to check for SPI mode, let's leave that to
internals of mmc_send_cid(). In this way the code gets cleaner and it
becomes clear what is specific to SPI and non-SPI mode.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>

The mmc_send_cid() is never called using non SPI mode. Thus, let's remove
the redundant code dealing with this.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>

Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>

The mmc_flush_cache() is a eMMC specific function, let's move it to
mmc_ops.c to make that clear.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>

The mmc_interrupt_hpi() is a eMMC specific function, let's move it to
mmc_ops.c to make that clear. The move also enables us to make
mmc_send_hpi_cmd() static, so let's do that change as well.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>

The mmc_start_bkops(), mmc_stop_bkops() and mmc_read_bkops_status()
functions are all specific to eMMCs. To make this clear, let's move them
from from core.c to mmc_ops.c and take the opportunity to make
mmc_read_bkops_status() static.

While moving them, get rid of MMC_BKOPS_MAX_TIMEOUT (4 min) and use the
common default timeout MMC_OPS_TIMEOUT_MS (10 min) instead, as there is no
need to have specific default timeout for bkops.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>

The mmc_start|stop_bkops(), mmc_read_bkops_status() and mmc_interrupt_hpi()
functions are all used from within the mmc core module, thus there are no
need to use EXPORT_SYMBOL() for them, so let's remove it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>

Drivers core will runtime suspend a device with no driver. That means the
SDIO card will be runtime suspended as soon as it is added. It is then
runtime resumed to add each function. That is entirely pointless, so add
pm runtime get/put to keep the SDIO card runtime resumed until the function
devices have been added.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

The error path deletes the device by calling mmc_sdio_remove() which must
be called without the host claimed. Simplify the error path so it does just
that and add a comment about why we don't disable runtime PM.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Using the device_property interfaces allows mmc drivers to work
on platforms which run on either device tree or ACPI.
Signed-off-by: NDavid Woods <dwoods@mellanox.com>
Reviewed-by: NChris Metcalf <cmetcalf@mellanox.com>
Cc: stable@vger.linux.org
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/block.c:1929:3-4: Unneeded semicolon

 Remove unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

CC: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

The only reason to why the mmc block device driver needs to implements its
own version of how to get the status of the card, is that it needs to
specify a different amount of retries.

Therefore add a new exported function which allows the caller to specify
the number of retries and convert everybody to use it, as this simplifies
the code.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>

This moves the boot partition lock command (issued from sysfs)
into a custom block layer request, just like the ioctl()s,
getting rid of yet another instance of mmc_get_card().

Since we now have two operations issuing special DRV_OP's, we
rename the result variable ->drv_op_result.

Tested by locking the boot partition from userspace:
> cd /sys/devices/platform/soc/80114000.sdi4_per2/mmc_host/mmc3/
     mmc3:0001/block/mmcblk3/mmcblk3boot0
> echo 1 > ro_lock_until_next_power_on
[  178.645324] mmcblk3boot1: Locking boot partition ro until next power on
[  178.652221] mmcblk3boot0: Locking boot partition ro until next power on

Also tested this with a huge dd job in the background: it
is now possible to lock the boot partitions on the card even
under heavy I/O.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

We will need to access static functions above the pure block layer
operations in the file, so move the driver operations issue
function down so we can see all non-blocklayer symbols.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

We will expand the DRV_OP usage, so we need to know which
operation we're performing. Tag the operations with an
enum:ed type and rename the function so it is clear that
it deals with any command and put a switch statement in
it. Currently only ioctls are supported.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Just as we can use blk_mq_rq_from_pdu() to get the per-request
tag we can use blk_mq_rq_to_pdu() to get a request from a tag.
Introduce a static inline helper so we are on the clear what
is happening.
Suggested-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Omit an extra message for memory allocation failures.

This issue was detected by using the Coccinelle software.

Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdfSigned-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

commit cdf8a6fb
"mmc: block: Introduce queue semantics"
deleted the last user of mmc_req_is_special() and it was
a horrible hack to classify requests as "special" or
"not special" to begin with, so delete the helper.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

This switches also the multiple-command ioctl() call to issue
all ioctl()s through the block layer instead of going directly
to the device.

We extend the passed argument with an argument count and loop
over all passed commands in the ioctl() issue function called
from the block layer.

By doing this we are again loosening the grip on the big host
lock, since two calls to mmc_get_card()/mmc_put_card() are
removed.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NAvri Altman <Avri.Altman@sandisk.com>

This wraps single ioctl() commands into block requests using
the custom block layer request types REQ_OP_DRV_IN and
REQ_OP_DRV_OUT.

By doing this we are loosening the grip on the big host lock,
since two calls to mmc_get_card()/mmc_put_card() are removed.

We are storing the ioctl() in/out argument as a pointer in
the per-request struct mmc_blk_request container. Since we
now let the block layer allocate this data, blk_get_request()
will allocate it for us and we can immediately dereference
it and use it to pass the argument into the block layer.

We refactor the if/else/if/else ladder in mmc_blk_issue_rq()
as part of the job, keeping some extra attention to the
case when a NULL req is passed into this function and
making that pipeline flush more explicit.

Tested on the ux500 with the userspace:
mmc extcsd read /dev/mmcblk3
resulting in a successful EXTCSD info dump back to the
console.

This commit fixes a starvation issue in the MMC/SD stack
that can be easily provoked in the following way by
issueing the following commands in sequence:

> dd if=/dev/mmcblk3 of=/dev/null bs=1M &
> mmc extcs read /dev/mmcblk3

Before this patch, the extcsd read command would hang
(starve) while waiting for the dd command to finish since
the block layer was holding the card/host lock.

After this patch, the extcsd ioctl() command is nicely
interpersed with the rest of the block commands and we
can issue a bunch of ioctl()s from userspace while there
is some busy block IO going on without any problems.

Conversely userspace ioctl()s can no longer starve
the block layer by holding the card/host lock.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NAvri Altman <Avri.Altman@sandisk.com>

The variable is_rpmb is clearly a bool and even assigned true
and false, yet declared as an int.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

The mmc_queue_req is a per-request state container the MMC core uses
to carry bounce buffers, pointers to asynchronous requests and so on.
Currently allocated as a static array of objects, then as a request
comes in, a mmc_queue_req is assigned to it, and used during the
lifetime of the request.

This is backwards compared to how other block layer drivers work:
they usally let the block core provide a per-request struct that get
allocated right beind the struct request, and which can be obtained
using the blk_mq_rq_to_pdu() helper. (The _mq_ infix in this function
name is misleading: it is used by both the old and the MQ block
layer.)

The per-request struct gets allocated to the size stored in the queue
variable .cmd_size initialized using the .init_rq_fn() and
cleaned up using .exit_rq_fn().

The block layer code makes the MMC core rely on this mechanism to
allocate the per-request mmc_queue_req state container.

Doing this make a lot of complicated queue handling go away. We only
need to keep the .qnct that keeps count of how many request are
currently being processed by the MMC layer. The MQ block layer will
replace also this once we transition to it.

Doing this refactoring is necessary to move the ioctl() operations
into custom block layer requests tagged with REQ_OP_DRV_[IN|OUT]
instead of the custom code using the BigMMCHostLock that we have
today: those require that per-request data be obtainable easily from
a request after creating a custom request with e.g.:

struct request *rq = blk_get_request(q, REQ_OP_DRV_IN, __GFP_RECLAIM);
struct mmc_queue_req *mq_rq = req_to_mq_rq(rq);

And this is not possible with the current construction, as the request
is not immediately assigned the per-request state container, but
instead it gets assigned when the request finally enters the MMC
queue, which is way too late for custom requests.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
[Ulf: Folded in the fix to drop a call to blk_cleanup_queue()]
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NHeiner Kallweit <hkallweit1@gmail.com>

This option is activated by all multiplatform configs and what
not so we almost always have it turned on, and the memory it
saves is negligible, even more so moving forward. The actual
bounce buffer only gets allocated only when used, the only
thing the ifdefs are saving is a little bit of code.

It is highly improper to have this as a Kconfig option that
get turned on by Kconfig, make this a pure runtime-thing and
let the host decide whether we use bounce buffers. We add a
new property "disable_bounce" to the host struct.

Notice that mmc_queue_calc_bouncesz() already disables the
bounce buffers if host->max_segs != 1, so any arch that has a
maximum number of segments higher than 1 will have bounce
buffers disabled.

The option CONFIG_MMC_BLOCK_BOUNCE is default y so the
majority of platforms in the kernel already have it on, and
it then gets turned off at runtime since most of these have
a host->max_segs > 1. The few exceptions that have
host->max_segs == 1 and still turn off the bounce buffering
are those that disable it in their defconfig.

Those are the following:

arch/arm/configs/colibri_pxa300_defconfig
arch/arm/configs/zeus_defconfig
- Uses MMC_PXA, drivers/mmc/host/pxamci.c
- Sets host->max_segs = NR_SG, which is 1
- This needs its bounce buffer deactivated so we set
  host->disable_bounce to true in the host driver

arch/arm/configs/davinci_all_defconfig
- Uses MMC_DAVINCI, drivers/mmc/host/davinci_mmc.c
- This driver sets host->max_segs to MAX_NR_SG, which is 16
- That means this driver anyways disabled bounce buffers
- No special action needed for this platform

arch/arm/configs/lpc32xx_defconfig
arch/arm/configs/nhk8815_defconfig
arch/arm/configs/u300_defconfig
- Uses MMC_ARMMMCI, drivers/mmc/host/mmci.[c|h]
- This driver by default sets host->max_segs to NR_SG,
  which is 128, unless a DMA engine is used, and in that case
  the number of segments are also > 1
- That means this driver already disables bounce buffers
- No special action needed for these platforms

arch/arm/configs/sama5_defconfig
- Uses MMC_SDHCI, MMC_SDHCI_PLTFM, MMC_SDHCI_OF_AT91, MMC_ATMELMCI
- Uses drivers/mmc/host/sdhci.c
- Normally sets host->max_segs to SDHCI_MAX_SEGS which is 128 and
  thus disables bounce buffers
- Sets host->max_segs to 1 if SDHCI_USE_SDMA is set
- SDHCI_USE_SDMA is only set by SDHCI on PCI adapers
- That means that for this platform bounce buffers are already
  disabled at runtime
- No special action needed for this platform

arch/blackfin/configs/CM-BF533_defconfig
arch/blackfin/configs/CM-BF537E_defconfig
- Uses MMC_SPI (a simple MMC card connected on SPI pins)
- Uses drivers/mmc/host/mmc_spi.c
- Sets host->max_segs to MMC_SPI_BLOCKSATONCE which is 128
- That means this platform already disables bounce buffers at
  runtime
- No special action needed for these platforms

arch/mips/configs/cavium_octeon_defconfig
- Uses MMC_CAVIUM_OCTEON, drivers/mmc/host/cavium.c
- Sets host->max_segs to 16 or 1
- Setting host->disable_bounce to be sure for the 1 case

arch/mips/configs/qi_lb60_defconfig
- Uses MMC_JZ4740, drivers/mmc/host/jz4740_mmc.c
- This sets host->max_segs to 128 so bounce buffers are
  already runtime disabled
- No action needed for this platform

It would be interesting to come up with a list of the platforms
that actually end up using bounce buffers. I have not been
able to infer such a list, but it occurs when
host->max_segs == 1 and the bounce buffering is not explicitly
disabled.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

For hosts not supporting MMC_CAP2_SDIO_IRQ_NOTHREAD but MMC_CAP_SDIO_IRQ,
the SDIO IRQs are processed from a dedicated kernel thread. For these
cases, the host calls mmc_signal_sdio_irq() from its ISR to signal a new
SDIO IRQ.

Signaling an SDIO IRQ makes the host's ->enable_sdio_irq() callback to be
invoked to temporary disable the IRQs, before the kernel thread is woken up
to process it. When processing of the IRQs are completed, they are
re-enabled by the kernel thread, again via invoking the host's
->enable_sdio_irq().

The observation from this, is that the execution path is being unnecessary
complex, as the host driver already knows that it needs to temporary
disable the IRQs before signaling a new one. Moreover, replacing the kernel
thread with a work/workqueue would not only greatly simplify the code, but
also make it more robust.

To address the above problems, let's continue to build upon the support for
MMC_CAP2_SDIO_IRQ_NOTHREAD, as it already implements SDIO IRQs to be
processed without using the clumsy kernel thread and without the ping-pong
calls of the host's ->enable_sdio_irq() callback for each processed IRQ.

Therefore, let's add new API sdio_signal_irq(), which enables hosts to
signal/process SDIO IRQs by using a work/workqueue, rather than using the
kernel thread.

Add also a new host callback ->ack_sdio_irq(), which the work invokes when
the SDIO IRQs have been processed. This informs the host about when it
shall re-enable the SDIO IRQs. Potentially, we could re-use the existing
->enable_sdio_irq() callback instead of adding a new one, however it has
turned out that it's more convenient for hosts to get this information via
a separate callback.

Hosts that wants to use this new method to signal/process SDIO IRQs, must
enable MMC_CAP2_SDIO_IRQ_NOTHREAD and implement the ->ack_sdio_irq()
callback.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>

In cases when MMC_CAP2_SDIO_IRQ_NOTHREAD is set, there is a minor window
for when the mmc host could call sdio_run_irqs(), while in fact an SDIO
func driver could have decided to released the SDIO IRQ via a call to
sdio_release_irq(). In this scenario, processing of the SDIO IRQs are done
even if there is none IRQ claimed, which is not what we want.

To prevent this from happen, close the window by validating that at least
one SDIO IRQs is claimed, before deciding to process them.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>

In case if a pwrseq-emmc has been bound to the host, a call to
mmc_power_up() triggers an eMMC HW reset via the pwrseq_emmc's
->post_power_on() callback. This isn't really what we want, as
mmc_power_up() is called each time when resuming the card.

As a matter of fact, the current approach may also violate the eMMC spec,
as the involved delays managed in pwrseq_emmc assumes both VCC and VCCQ has
been turned on, which isn't the case for VCCQ, unless the regulator is
always on.

Fix this behaviour by aligning to the same procedure used when the mmc host
implements the ->hw_reset() callback and has the MMC_CAP_HW_RESET flag set.
In this way the eMMC HW reset is issued at card detection scan, to cope
with bogus bootloaders and in the error recovery path via the mmc specific
bus_ops->reset() callback.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NMarek Szyprowski <m.szyprowski@samsung.com>

The ->reset() callback is needed to implement a better support for eMMC HW
reset. The following changes will take advantage of the new callback.
Suggested-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NMarek Szyprowski <m.szyprowski@samsung.com>

Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

If the optional power-off-delay-us property is found, insert the
corresponding delay after asserting the GPIO during power off. This enables
a graceful shutdown sequence for some devices.

Cc: linux-mmc@vger.kernel.org
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>

Some hosts controllers, like Cavium, needs to know whether the card
operates in byte- or block-address mode. Therefore export a new API,
mmc_card_is_blockaddr(), which provides this information.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NSteven J. Hill <Steven.Hill@cavium.com>
Acked-by: NDavid Daney <david.daney@cavium.com>

The host may issue an I/O abort by writing to the CCCR at any time
during I/O read operation via CMD52. And host may need suspend
transcation during write busy stage in SDIO suspend/resume scenario.
>From other side, a card may accept CMD52 during data transfer phase.

Previous implement would block issuing above command in busy stage.
It cause function driver can't implement as proper way and has no
opportunity to do some coverage in error case via I/O abort etc.

We need bypass some necessary operation during busy check stage.
Signed-off-by: NJiajie Hao <jiajie.hao@mediatek.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>