[PATCH v2 0/4] mtd: phram improvements

[Vincent Whitchurch <vincent.whitchurch@axis.com>]

v2:
- Add note on what "phram" means in binding.
- Use /schemas/mtd/mtd.yaml instead of relative pathUse /schemas/mtd/mtd.yaml
  instead of relative path in binding.

The phram driver in the MTD subsystem can be used to allow the kernel to use an
MTD or (via mtdblock) a block device in RAM (with the contents loaded by a
bootloader for example).  This series has some improvements to make it more
usable by adding device tree support and to significantly improve its
performance by using cached mappings when possible.

I use this feature to pass the rootfs to the kernel when booting from RAM.  The
boot is much faster and requires less memory than initrd (which is on top of
that being deprecated), and it allows the same disk images to be used when
booting from RAM, unlike initramfs.

Cc: linux-mtd@lists.infradead.org

Cc: devicetree@vger.kernel.org
Cc: robh+dt@kernel.org
Cc: krzk+dt@kernel.org
Cc: frowand.list@gmail.com

Cc: linux-kernel@vger.kernel.org

Vincent Whitchurch (4):
  mtd: core: Check devicetree alias for index
  dt-bindings: reserved-memory: Add phram
  mtd: phram: Allow probing via reserved-memory
  mtd: phram: Allow cached mappings

 .../bindings/reserved-memory/phram.yaml       | 47 +++++++++++
 drivers/mtd/devices/phram.c                   | 78 +++++++++++++++++--
 drivers/mtd/mtdcore.c                         | 11 ++-
 drivers/of/platform.c                         |  1 +
 4 files changed, 129 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/reserved-memory/phram.yaml

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2.34.1