Re: [PATCH v3 0/7] Refactor reserved memory regions handling code

[Rob Herring]

On Thu, Mar 26, 2026 at 4:58 AM Marek Szyprowski
<m.szyprowski@xxxxxxxxxxx> wrote:
>
> Hi Rob
>
> On 25.03.2026 15:16, Rob Herring wrote:
> > On Wed, Mar 25, 2026 at 10:00:16AM +0100, Marek Szyprowski wrote:
> >> The reserved memory regions handling code was reworked to handle
> >> unlimited so called "static" memory nodes in commit 00c9a452a235 ("of:
> >> reserved_mem: Add code to dynamically allocate reserved_mem array").
> >>
> >> The side effect of this rework was a set of bugs fixed later by commits
> >> 0fd17e598333 ("of: reserved_mem: Allow reserved_mem framework detect
> >> "cma=" kernel param") and 2c223f7239f3 ("of: reserved_mem: Restructure
> >> call site for dma_contiguous_early_fixup()"). As a result, the code in
> >> drivers/of/of_reserved_mem.c became a mix of generic code and CMA
> >> specific fixups.
> >>
> >> In this patchset I try to untangle this spaghetti and perform some code
> >> cleanup. I hope nothing breaks this time.
> >>
> >> Best regards
> >> Marek Szyprowski, PhD
> >> Samsung R&D Institute Poland
> >>
> >>
> >> Changelog:
> >>
> >> v3:
> >> - fixed more issues pointed by Sashiko in
> >>    https://protect2.fireeye.com/v1/url?k=c0975fdb-a11c4aed-c096d494-74fe485cbff1-5d0a8d4ece172e7b&q=1&e=abd3a151-11c5-430e-a6ac-b04cc3b34ab7&u=https%3A%2F%2Fsashiko.dev%2F%23%2Fpatchset%2F20260323100901.4079171-1-m.szyprowski%40samsung.com
> >>    (restored use of _OF_DECLARE macro, extended some comments and commit
> >>    descriptions, the remaining items I consider not relevant)
> >>
> >> v2: https://lore.kernel.org/all/20260323100901.4079171-1-m.szyprowski@xxxxxxxxxxx/
> >> - added missing ops assignment removal in tegra210-emc-table and swiotlb
> >>    drivers
> >> - fixed issues pointed by kernel test robot and Sashiko: removed typos,
> >>    improved comments
> >> - fixed incorrect node passed to fdt_validate_reserved_mem_node() in
> >>    fdt_scan_reserved_mem_reg_nodes()
> >>
> >> v1: https://lore.kernel.org/all/20260313150802.1121442-1-m.szyprowski@xxxxxxxxxxx/
> >> - initial version
> >>
> >>
> >> Patch summary:
> >>
> >> Marek Szyprowski (7):
> >>    of: reserved_mem: remove fdt node from the structure
> >>    of: reserved_mem: use -ENODEV instead of -ENOENT
> >>    of: reserved_mem: switch to ops based OF_DECLARE()
> >>    of: reserved_mem: replace CMA quirks by generic methods
> >>    of: reserved_mem: rearrange code a bit
> >>    of: reserved_mem: clarify fdt_scan_reserved_mem*() functions
> >>    of: reserved_mem: rework fdt_init_reserved_mem_node()
> > I've applied the series, thanks!
>
> I forgot to mention this earlier. There are other pending changes
> tokernel/dma/contiguous.c like
> https://lore.kernel.org/all/20260303-dma-buf-heaps-as-modules-v3-0-24344812c707@xxxxxxxxxx/
> which I would like to merge to -next. This conflicts with this patchset.
> Could You provide a stable branch with those changes to let me resolve
> conflicts in kernel/dma/contiguous.c on top of it?

Here you go:

The following changes since commit 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f:

  Linux 7.0-rc1 (2026-02-22 13:18:59 -0800)

are available in the Git repository at:

  ssh://git@xxxxxxxxxxxxxxxxxxx/pub/scm/linux/kernel/git/robh/linux.git
dt-reserved-mem-cleanups

for you to fetch changes up to 34e0e2a8ea9e9e4f4dceb33072103dffaa1366b3:

  of: reserved_mem: rework fdt_init_reserved_mem_node() (2026-03-26
14:12:02 -0500)

----------------------------------------------------------------
Marek Szyprowski (7):
      of: reserved_mem: remove fdt node from the structure
      of: reserved_mem: use -ENODEV instead of -ENOENT
      of: reserved_mem: switch to ops based OF_DECLARE()
      of: reserved_mem: replace CMA quirks by generic methods
      of: reserved_mem: rearrange code a bit
      of: reserved_mem: clarify fdt_scan_reserved_mem*() functions
      of: reserved_mem: rework fdt_init_reserved_mem_node()

 drivers/memory/tegra/tegra210-emc-table.c |  19 +++++-----
 drivers/of/fdt.c                          |   2 +-
 drivers/of/of_private.h                   |   2 +-
 drivers/of/of_reserved_mem.c              | 320
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------------------------------------------------------
 include/linux/cma.h                       |  10 ------
 include/linux/dma-map-ops.h               |   3 --
 include/linux/of_reserved_mem.h           |  16 +++++----
 kernel/dma/coherent.c                     |  19 +++++-----
 kernel/dma/contiguous.c                   |  86
+++++++++++++++++++++++++++++++--------------
 kernel/dma/swiotlb.c                      |  19 +++++-----
 10 files changed, 285 insertions(+), 211 deletions(-)