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| author | Hector Martin <marcan@marcan.st> | 2021-02-11 21:41:56 +0900 |
|---|---|---|
| committer | Hector Martin <marcan@marcan.st> | 2021-04-08 20:18:41 +0900 |
| commit | 89897f739d7b5e8d572909efc3c2ba7583b8aaba (patch) | |
| tree | 384e91b402a52f0e89cae60d889c42eaf4b7730f /Documentation/vm | |
| parent | b10eb2d50911f98a8f1cacf00b1b677339593f4c (diff) | |
of/address: Add infrastructure to declare MMIO as non-posted
This implements the 'nonposted-mmio' boolean property. Placing this
property in a bus marks all direct child devices as requiring
non-posted MMIO mappings. If no such property is found, the default
is posted MMIO.
of_mmio_is_nonposted() performs this check to determine if a given
device has requested non-posted MMIO.
of_address_to_resource() uses this to set the IORESOURCE_MEM_NONPOSTED
flag on resources that require non-posted MMIO.
of_iomap() and of_io_request_and_map() then use this flag to pick the
correct ioremap() variant.
This mechanism is currently restricted to builds that support Apple ARM
platforms, as an optimization.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hector Martin <marcan@marcan.st>
Diffstat (limited to 'Documentation/vm')
0 files changed, 0 insertions, 0 deletions