kernel/linux.git/include/linux/mmc/host.h, branch v6.19.11

mmc: core: Avoid bitfield RMW for claim/retune flags

2026-03-19T15:15:10+00:00

commit 901084c51a0a8fb42a3f37d2e9c62083c495f824 upstream. Move claimed and retune control flags out of the bitfield word to avoid unrelated RMW side effects in asynchronous contexts. The host->claimed bit shared a word with retune flags. Writes to claimed in __mmc_claim_host() or retune_now in mmc_mq_queue_rq() can overwrite other bits when concurrent updates happen in other contexts, triggering spurious WARN_ON(!host->claimed). Convert claimed, can_retune, retune_now and retune_paused to bool to remove shared-word coupling. Fixes: 6c0cedd1ef952 ("mmc: core: Introduce host claiming by context") Fixes: 1e8e55b67030c ("mmc: block: Add CQE support") Cc: stable@vger.kernel.org Suggested-by: Adrian Hunter Signed-off-by: Penghe Geng Acked-by: Adrian Hunter Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman

mmc: core: Parse and use the new max-sd-hs-hz DT property

2025-09-12T12:49:36+00:00

Introduce a new device tree flag to cap the maximum High-Speed (HS) mode frequency for SD cards, accommodating board-specific electrical limitations which cannot support the default 50Mhz HS frequency and others. Signed-off-by: Sarthak Garg Signed-off-by: Ulf Hansson

mmc: core: Add infrastructure for undervoltage handling

2025-08-22T10:08:07+00:00

Implement the core infrastructure to allow MMC bus types to handle REGULATOR_EVENT_UNDER_VOLTAGE events from power regulators. This is primarily aimed at allowing devices like eMMC to perform an emergency shutdown to prevent data corruption when a power failure is imminent. This patch introduces: - A new 'handle_undervoltage' function pointer to 'struct mmc_bus_ops'. Bus drivers (e.g., for eMMC) can implement this to define their emergency procedures. - A workqueue ('uv_work') in 'struct mmc_supply' to handle the event asynchronously in a high-priority context. - A new function 'mmc_handle_undervoltage()' which is called from the workqueue. It stops the host queue to prevent races with card removal, checks for the bus op, and invokes the handler. - Functions to register and unregister the regulator notifier, intended to be called by bus drivers like 'mmc_attach_mmc' when a compatible card is detected. The notifier is only registered for the main vmmc supply, as undervoltage handling for vqmmc or vqmmc2 is not required at this time. Signed-off-by: Oleksij Rempel Link: https://lore.kernel.org/r/20250821130751.2089587-2-o.rempel@pengutronix.de Signed-off-by: Ulf Hansson

mmc: core: add mmc_read_tuning

2025-08-19T12:34:15+00:00

Provide a function to the MMC hosts to read some blocks of data as part of their tuning. This function only returns the status of the read operation, not the data read. Signed-off-by: Benoît Monin Link: https://lore.kernel.org/r/20250818-mobileye-emmc-for-upstream-4-v4-5-34ecb3995e96@bootlin.com Signed-off-by: Ulf Hansson

mmc: crypto: add mmc_from_crypto_profile()

2024-12-19T13:43:28+00:00

Add a helper function that encapsulates a container_of expression. For now there is just one user but soon there will be more. Signed-off-by: Eric Biggers Message-ID: <20241213041958.202565-7-ebiggers@kernel.org> Signed-off-by: Ulf Hansson

mmc: core: Support UHS-II card control and access

2024-10-24T12:22:24+00:00

Embed UHS-II access/control functionality into the MMC request processing flow. Signed-off-by: Jason Lai Signed-off-by: Victor Shih Message-ID: <20241018105333.4569-2-victorshihgli@gmail.com> [Ulf: A couple of cleanups and fixed sd_uhs2_power_off()] Signed-off-by: Ulf Hansson

mmc: core: Add definitions for SD UHS-II cards

2024-10-14T10:40:10+00:00

Add UHS-II specific data structures for commands and defines for registers, as described in Part 1 UHS-II Addendum Version 1.01. UHS-II related definitions are listed below: 1. UHS-II card capability: sd_uhs2_caps{} 2. UHS-II configuration: sd_uhs2_config{} 3. UHS-II register I/O address and register field definitions: sd_uhs2.h Signed-off-by: Jason Lai Signed-off-by: Victor Shih Link: https://lore.kernel.org/r/20240913102836.6144-6-victorshihgli@gmail.com Signed-off-by: Ulf Hansson

mmc: core: Extend support for mmc regulators with a vqmmc2

2024-10-14T10:40:10+00:00

To allow an additional external regulator to be controlled by an mmc host driver, let's add support for a vqmmc2 regulator to the mmc core. For an SD UHS-II interface the vqmmc2 regulator may correspond to the so called vdd2 supply, as described by the SD spec. Initially, only 1.8V is needed, hence limit the new helper function, mmc_regulator_set_vqmmc2() to this too. Note that, to allow for flexibility mmc host drivers need to manage the enable/disable of the vqmmc2 regulator themselves, while the regulator is looked up through the common mmc_regulator_get_supply(). Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20240913102836.6144-5-victorshihgli@gmail.com

mmc: core: Announce successful insertion of an SD UHS-II card

2024-10-14T10:40:10+00:00

To inform the users about SD UHS-II cards, let's extend the print at card insertion with a "UHS-II" substring. Within this change, it seems reasonable to convert from using "ultra high speed" into "UHS-I speed", for the UHS-I type, as it should makes it more clear. Note that, the new print for UHS-II cards doesn't include the actual selected speed mode. Instead, this is going to be added from subsequent change. Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20240913102836.6144-4-victorshihgli@gmail.com

mmc: core: Prepare to support SD UHS-II cards

2024-10-14T10:40:10+00:00

The SD UHS-II interface was introduced to the SD spec v4.00 several years ago. The interface is fundamentally different from an electrical and a protocol point of view, comparing to the legacy SD interface. However, the legacy SD protocol is supported through a specific transport layer (SD-TRAN) defined in the UHS-II addendum of the spec. This allows the SD card to be managed in a very similar way as a legacy SD card, hence a lot of code can be re-used to support these new types of cards through the mmc subsystem. Moreover, an SD card that supports the UHS-II interface shall also be backwards compatible with the legacy SD interface, which allows a UHS-II card to be inserted into a legacy slot. As a matter of fact, this is already supported by mmc subsystem as of today. To prepare to add support for UHS-II, this change puts the basic foundation in the mmc core in place, allowing it to be more easily reviewed before subsequent changes implements the actual support. Basically, the approach here adds a new UHS-II bus_ops type and adds a separate initialization path for the UHS-II card. The intent is to avoid us from sprinkling the legacy initialization path, but also to simplify implementation of the UHS-II specific bits. At this point, there is only one new host ops added to manage the various ios settings needed for UHS-II. Additional host ops that are needed, are being added from subsequent changes. Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20240913102836.6144-3-victorshihgli@gmail.com