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path: root/drivers/mmc/core/queue.h
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2018-11-17mmc: stop abusing the request queue_lock pointerChristoph Hellwig1-2/+2
Replace the lock in mmc_blk_data that is only used through a pointer in struct mmc_queue and to protect fields in that structure with an actual lock in struct mmc_queue. Suggested-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-15mmc: stop abusing the request queue_lock pointerChristoph Hellwig1-0/+1
mmc uses the block layer struct request pointer to indirect their own lock to the mmc_queue structure, given that the original lock isn't reachable outside of block.c. Add a lock pointer to struct mmc_queue instead and stop overriding the block layer lock which protects fields entirely separate from the mmc use. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-15mmc: simplify queue initializationChristoph Hellwig1-2/+1
Merge three functions initializing the queue into a single one, and drop an unused argument for it. Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-21mmc: block: Fix unsupported parallel dispatch of requestsAdrian Hunter1-0/+1
The mmc block driver does not support parallel dispatch of requests. In normal circumstances, all requests are anyway funneled through a single work item, so parallel dispatch never happens. However it can happen if there is no elevator. Fix that by detecting if a dispatch is in progress and returning busy (BLK_STS_RESOURCE) in that case Fixes: 81196976ed94 ("mmc: block: Add blk-mq support") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-12-11mmc: block: Remove code no longer needed after the switch to blk-mqAdrian Hunter1-15/+0
Remove code no longer needed after the switch to blk-mq. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-12-11mmc: block: blk-mq: Add support for direct completionAdrian Hunter1-0/+1
For blk-mq, add support for completing requests directly in the ->done callback. That means that error handling and urgent background operations must be handled by recovery_work in that case. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Linus Walleij <linus.walleij@linaro.org>
2017-12-11mmc: block: Add CQE supportAdrian Hunter1-0/+18
Add CQE support to the block driver, including: - optionally using DCMD for flush requests - "manually" issuing discard requests - issuing read / write requests to the CQE - supporting block-layer timeouts - handling recovery - supporting re-tuning CQE offers 25% - 50% better random multi-threaded I/O. There is a slight (e.g. 2%) drop in sequential read speed but no observable change to sequential write. CQE automatically sends the commands to complete requests. However it only supports reads / writes and so-called "direct commands" (DCMD). Furthermore DCMD is limited to one command at a time, but discards require 3 commands. That makes issuing discards through CQE very awkward, but some CQE's don't support DCMD anyway. So for discards, the existing non-CQE approach is taken, where the mmc core code issues the 3 commands one at a time i.e. mmc_erase(). Where DCMD is used, is for issuing flushes. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Linus Walleij <linus.walleij@linaro.org>
2017-12-11mmc: block: Add blk-mq supportAdrian Hunter1-0/+32
Define and use a blk-mq queue. Discards and flushes are processed synchronously, but reads and writes asynchronously. In order to support slow DMA unmapping, DMA unmapping is not done until after the next request is started. That means the request is not completed until then. If there is no next request then the completion is done by queued work. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Linus Walleij <linus.walleij@linaro.org>
2017-11-13Merge tag 'mmc-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmcLinus Torvalds1-2/+2
Pull MMC updates from Ulf Hansson: "MMC core: - Introduce host claiming by context to support blkmq - Preparations for enabling CQE (eMMC CMDQ) requests - Re-factorizations to prepare for blkmq support - Re-factorizations to prepare for CQE support - Fix signal voltage switch for SD cards without power cycle - Convert RPMB to a character device - Export eMMC revision via sysfs - Support eMMC DT binding for fixed driver type - Document mmc_regulator_get_supply() API MMC host: - omap_hsmmc: Updated regulator management for PBIAS - sdhci-omap: Add new OMAP SDHCI driver - meson-mx-sdio: New driver for the Amlogic Meson8 and Meson8b SoCs - sdhci-pci: Add support for Intel CDF - sdhci-acpi: Fix voltage switch for some Intel host controllers - sdhci-msm: Enable delay circuit calibration clocks - sdhci-msm: Manage power IRQ properly - mediatek: Add support of mt2701/mt2712 - mediatek: Updates management of clocks and tunings - mediatek: Upgrade eMMC HS400 support - rtsx_pci: Update tuning for gen3 PCI-Express - renesas_sdhi: Support R-Car Gen[123] fallback compatibility strings - Catch all errors when getting regulators - Various additional improvements and cleanups" * tag 'mmc-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (91 commits) sdhci-fujitsu: add support for setting the CMD_DAT_DELAY attribute dt-bindings: sdhci-fujitsu: document cmd-dat-delay property mmc: tmio: Replace msleep() of 20ms or less with usleep_range() mmc: dw_mmc: Convert timers to use timer_setup() mmc: dw_mmc: Cleanup the DTO timer like the CTO one mmc: vub300: Use common code in __download_offload_pseudocode() mmc: tmio: Use common error handling code in tmio_mmc_host_probe() mmc: Convert timers to use timer_setup() mmc: sdhci-acpi: Fix voltage switch for some Intel host controllers mmc: sdhci-acpi: Let devices define their own private data mmc: mediatek: perfer to use rise edge latching for cmd line mmc: mediatek: improve eMMC hs400 mode read performance mmc: mediatek: add latch-ck support mmc: mediatek: add support of source_cg clock mmc: mediatek: add stop_clk fix and enhance_rx support mmc: mediatek: add busy_check support mmc: mediatek: add async fifo and data tune support mmc: mediatek: add pad_tune0 support mmc: mediatek: make hs400_tune_response only for mt8173 arm64: dts: mt8173: remove "mediatek, mt8135-mmc" from mmc nodes ...
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-30mmc: block: Delete mmc_access_rpmb()Linus Walleij1-2/+0
This function is used by the block layer queue to bail out of requests if the current request is towards an RPMB "block device". This was done to avoid boot time scanning of this "block device" which was never really a block device, thus duct-taping over the fact that it was badly engineered. This problem is now gone as we removed the offending RPMB block device in another patch and replaced it with a character device. Cc: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-10-30mmc: block: Convert RPMB to a character deviceLinus Walleij1-0/+2
The RPMB partition on the eMMC devices is a special area used for storing cryptographically safe information signed by a special secret key. To write and read records from this special area, authentication is needed. The RPMB area is *only* and *exclusively* accessed using ioctl():s from userspace. It is not really a block device, as blocks cannot be read or written from the device, also the signed chunks that can be stored on the RPMB are actually 256 bytes, not 512 making a block device a real bad fit. Currently the RPMB partition spawns a separate block device named /dev/mmcblkNrpmb for each device with an RPMB partition, including the creation of a block queue with its own kernel thread and all overhead associated with this. On the Ux500 HREFv60 platform, for example, the two eMMCs means that two block queues with separate threads are created for no use whatsoever. I have concluded that this block device design for RPMB is actually pretty wrong. The RPMB area should have been designed to be accessed from /dev/mmcblkN directly, using ioctl()s on the main block device. It is however way too late to change that, since userspace expects to open an RPMB device in /dev/mmcblkNrpmb and we cannot break userspace. This patch tries to amend the situation using the following strategy: - Stop creating a block device for the RPMB partition/area - Instead create a custom, dynamic character device with the same name. - Make this new character device support exactly the same set of ioctl()s as the old block device. - Wrap the requests back to the same ioctl() handlers, but issue them on the block queue of the main partition/area, i.e. /dev/mmcblkN We need to create a special "rpmb" bus type in order to get udev and/or busybox hot/coldplug to instantiate the device node properly. Before the patch, this appears in 'ps aux': 101 root 0:00 [mmcqd/2rpmb] 123 root 0:00 [mmcqd/3rpmb] After applying the patch these surplus block queue threads are gone, but RPMB is as usable as ever using the userspace MMC tools, such as 'mmc rpmb read-counter'. We get instead those dynamice devices in /dev: brw-rw---- 1 root root 179, 0 Jan 1 2000 mmcblk0 brw-rw---- 1 root root 179, 1 Jan 1 2000 mmcblk0p1 brw-rw---- 1 root root 179, 2 Jan 1 2000 mmcblk0p2 brw-rw---- 1 root root 179, 5 Jan 1 2000 mmcblk0p5 brw-rw---- 1 root root 179, 8 Jan 1 2000 mmcblk2 brw-rw---- 1 root root 179, 16 Jan 1 2000 mmcblk2boot0 brw-rw---- 1 root root 179, 24 Jan 1 2000 mmcblk2boot1 crw-rw---- 1 root root 248, 0 Jan 1 2000 mmcblk2rpmb brw-rw---- 1 root root 179, 32 Jan 1 2000 mmcblk3 brw-rw---- 1 root root 179, 40 Jan 1 2000 mmcblk3boot0 brw-rw---- 1 root root 179, 48 Jan 1 2000 mmcblk3boot1 brw-rw---- 1 root root 179, 33 Jan 1 2000 mmcblk3p1 crw-rw---- 1 root root 248, 1 Jan 1 2000 mmcblk3rpmb Notice the (248,0) and (248,1) character devices for RPMB. Cc: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-10-04mmc: Delete bounce buffer handlingLinus Walleij1-6/+0
In may, Steven sent a patch deleting the bounce buffer handling and the CONFIG_MMC_BLOCK_BOUNCE option. I chose the less invasive path of making it a runtime config option, and we merged that successfully for kernel v4.12. The code is however just standing in the way and taking up space for seemingly no gain on any systems in wide use today. Pierre says the code was there to improve speed on TI SDHCI controllers on certain HP laptops and possibly some Ricoh controllers as well. Early SDHCI controllers lacked the scatter-gather feature, which made software bounce buffers a significant speed boost. We are clearly talking about the list of SDHCI PCI-based MMC/SD card readers found in the pci_ids[] list in drivers/mmc/host/sdhci-pci-core.c. The TI SDHCI derivative is not supported by the upstream kernel. This leaves the Ricoh. What we can however notice is that the x86 defconfigs in the kernel did not enable CONFIG_MMC_BLOCK_BOUNCE option, which means that any such laptop would have to have a custom configured kernel to actually take advantage of this bounce buffer speed-up. It simply seems like there was a speed optimization for the Ricoh controllers that noone was using. (I have not checked the distro defconfigs but I am pretty sure the situation is the same there.) Bounce buffers increased performance on the OMAP HSMMC at one point, and was part of the original submission in commit a45c6cb81647 ("[ARM] 5369/1: omap mmc: Add new omap hsmmc controller for 2430 and 34xx, v3") This optimization was removed in commit 0ccd76d4c236 ("omap_hsmmc: Implement scatter-gather emulation") which found that scatter-gather emulation provided even better performance. The same was introduced for SDHCI in commit 2134a922c6e7 ("sdhci: scatter-gather (ADMA) support") I am pretty positively convinced that software scatter-gather emulation will do for any host controller what the bounce buffers were doing. Essentially, the bounce buffer was a reimplementation of software scatter-gather-emulation in the MMC subsystem, and it should be done away with. Cc: Pierre Ossman <pierre@ossman.eu> Cc: Juha Yrjola <juha.yrjola@solidboot.com> Cc: Steven J. Hill <Steven.Hill@cavium.com> Cc: Shawn Lin <shawn.lin@rock-chips.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Suggested-by: Steven J. Hill <Steven.Hill@cavium.com> Suggested-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-08-30mmc: debugfs: Move block debugfs into block moduleLinus Walleij1-0/+4
If we don't have the block layer enabled, we do not present card status and extcsd in the debugfs. Debugfs is not ABI, and maintaining files of no relevance for non-block devices comes at a high maintenance cost if we shall support it with the block layer compiled out. The debugfs entries suffer from all the same starvation issues as the other userspace things, under e.g. a heavy dd operation. The expected number of debugfs users utilizing these two debugfs files is already low as there is an ioctl() to get the same information using the mmc-tools, and of these few users the expected number of people using it on SDIO or combo cards are expected to be zero. It is therefore logical to move this over to the block layer when it is enabled, using the new custom requests and issue it using the block request queue. On the other hand it moves some debugfs code from debugfs.c and into block.c. Tested during heavy dd load by cat:in the status file. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-08-30mmc: block: Anonymize the drv op data pointerLinus Walleij1-1/+1
We have a data pointer for the ioctl() data, but we need to pass other data along with the DRV_OP:s, so make this a void * so it can be reused. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-06-20mmc: block: Move boot partition locking into a driver opLinus Walleij1-1/+3
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: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-06-20mmc: block: Tag DRV_OPs with a driver operation typeLinus Walleij1-0/+9
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: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-06-20mmc: block: remove req back pointerLinus Walleij1-1/+7
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: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-06-20mmc: queue: delete mmc_req_is_special()Linus Walleij1-8/+0
commit cdf8a6fb48882651049e468e6b16956fb83db86c "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: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-06-20mmc: block: move multi-ioctl() to use block layerLinus Walleij1-1/+2
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: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Avri Altman <Avri.Altman@sandisk.com>
2017-06-20mmc: block: move single ioctl() commands to block requestsLinus Walleij1-0/+3
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: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Avri Altman <Avri.Altman@sandisk.com>
2017-06-20mmc: core: Allocate per-request data using the block layer coreLinus Walleij1-10/+12
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: Linus Walleij <linus.walleij@linaro.org> [Ulf: Folded in the fix to drop a call to blk_cleanup_queue()] Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Heiner Kallweit <hkallweit1@gmail.com>
2017-04-24mmc: queue: Share mmc request array between partitionsAdrian Hunter1-0/+2
eMMC can have multiple internal partitions that are represented as separate disks / queues. However switching between partitions is only done when the queue is empty. Consequently the array of mmc requests that are queued can be shared between partitions saving memory. Keep a pointer to the mmc request queue on the card, and use that instead of allocating a new one for each partition. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-04-24mmc: block: Introduce queue semanticsAdrian Hunter1-3/+7
Change from viewing the requests in progress as 'current' and 'previous', to viewing them as a queue. The current request is allocated to the first free slot. The presence of incomplete requests is determined from the count (mq->qcnt) of entries in the queue. Non-read-write requests (i.e. discards and flushes) are not added to the queue at all and require no special handling. Also no special handling is needed for the MMC_BLK_NEW_REQUEST case. As well as allowing an arbitrarily sized queue, the queue thread function is significantly simpler. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-02-13mmc: queue: turn queue flags into boolsLinus Walleij1-3/+2
Instead of masking and setting two bits in the "flags" field for the mmc_queue, just use two bools named "suspended" and "new_request". The masking and setting would likely have race conditions anyways, it is better to use a simple member like this. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-02-13mmc: block: rename mmc_active to areqLinus Walleij1-1/+1
The mmc_active member of struct mmc_queue_req has a very confusing name: this is certainly not always "active", it is the asynchronous request associated by the mmc_queue_req but it is not guaranteed to be "active" in any sense, such as being running on the host. Simply rename this member to "areq". Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-02-13mmc: core: First step in cleaning up private mmc header filesUlf Hansson1-1/+5
This is the first step in cleaning up the private mmc header files. In this change we makes sure each header file builds standalone, as that helps to resolve dependencies. While changing this, it also seems reasonable to stop including other headers from inside a header itself which it don't depend upon. Additionally, in some cases such dependencies are better resolved by forward declaring the needed struct. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
2016-12-12mmc: block: Move files to coreUlf Hansson1-0/+64
Once upon a time it made sense to keep the mmc block device driver and its related code, in its own directory called card. Over time, more an more functions/structures have become shared through generic mmc header files, between the core and the card directory. In other words, the relationship between them has become closer. By sharing functions/structures via generic header files, it becomes easy for outside users to abuse them. In a way to avoid that from happen, let's move the files from card directory into the core directory, as it enables us to move definitions of functions/structures into mmc core specific header files. Note, this is only the first step in providing a cleaner mmc interface for outside users. Following changes will do the actual cleanup, as that is not part of this change. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>