So far our parsing of {iommu,msi}-map properites has always blindly
assumed that the output specifiers will always have exactly 1 cell.
This typically does happen to be the case, but is not actually enforced
(and the PCI msi-map binding even explicitly states support for 0 or 1
cells) - as a result we've now ended up with dodgy DTs out in the field
which depend on this behaviour to map a 1-cell specifier for a 2-cell
provider, despite that being bogus per the bindings themselves.
Since there is some potential use[1] in being able to map at least
single input IDs to multi-cell output specifiers (and properly support
0-cell outputs as well), add support for properly parsing and using the
target nodes' #cells values, albeit with the unfortunate complication of
still having to work around expectations of the old behaviour too.
-- Robin.
Unlike single #{}-cell, it is complex to establish a linear relation
between input 'id' and output specifier for multi-cell properties, thus
it is always expected that len never going to be > 1.
These changes have been tested on QEMU for the arm64 architecture.
[1] https://lore.kernel.org/all/[email protected]/
V9:
- Updated TO/CC list based on feedback to include all relevant
maintainers.
- No functional changes to the patches themselves.
Link to V8:
https://lore.kernel.org/all/[email protected]/
V8:
- Removed mentions of of_map_args from commit message to match code.
Link to V7:
https://lore.kernel.org/all/[email protected]/
V7:
- Removed of_map_id_args structure and replaced it with
of_phandle_args as suggested by Dmitry.
Link to V6:
https://lore.kernel.org/all/[email protected]/
V6:
- Fixed build error reported by kernel test bot.
Link to V5:
https://lore.kernel.org/all/[email protected]/
V5:
- Fixed Build Warnings.
- Raised PR for iommu-map dtschema:
https://github.com/devicetree-org/dt-schema/pull/184
Link to V4:
https://lore.kernel.org/all/[email protected]/
V4:
- Added Reviewed-by tag.
- Resolved warnings reported by kernel test bot, minor code
reorganization.
Link to V3:
https://lore.kernel.org/all/[email protected]/
V3:
- Added Reviewed-by tag.
- Updated of_map_id_args struct as a wrapper to of_phandle_args and
added comment description as suggested by Rob Herring.
Link to V2:
https://lore.kernel.org/all/[email protected]/
V2:
- Incorporated the patches from Robin that does the clean implementation.
- Dropped the patches the were adding multi-map support from this series
as suggested.
V1:
https://lore.kernel.org/all/[email protected]/
RFC:
https://lore.kernel.org/all/[email protected]/#r
Signed-off-by: Vijayanand Jitta <[email protected]>
---
Charan Teja Kalla (1):
of: factor arguments passed to of_map_id() into a struct
Robin Murphy (2):
of: Add convenience wrappers for of_map_id()
of: Respect #{iommu,msi}-cells in maps
drivers/cdx/cdx_msi.c | 3 +-
drivers/iommu/of_iommu.c | 6 +-
drivers/irqchip/irq-gic-its-msi-parent.c | 2 +-
drivers/of/base.c | 148 ++++++++++++++++++++++---------
drivers/of/irq.c | 3 +-
drivers/pci/controller/dwc/pci-imx6.c | 12 ++-
drivers/pci/controller/pcie-apple.c | 5 +-
drivers/xen/grant-dma-ops.c | 3 +-
include/linux/of.h | 33 +++++--
9 files changed, 152 insertions(+), 63 deletions(-)
---
base-commit: 3fa5e5702a82d259897bd7e209469bc06368bf31
change-id: 20260301-parse_iommu_cells-1c33768aebba
Best regards,
--
Vijayanand Jitta <[email protected]>
