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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-12 09:15:48 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-12 09:15:48 -0700 |
commit | c17b0aadb7d8f87de56a4a374a8131519c0f7422 (patch) | |
tree | 764af3fc7e29ffcb24f93b648f163358fb6e60a4 /scripts/dtc/libfdt/fdt.c | |
parent | e241e3f2bf975788a1b70dff2eb5180ca395b28e (diff) | |
parent | a71e7c44ffb7baea0c0795824afc34cc0bc1a301 (diff) | |
download | linux-c17b0aadb7d8f87de56a4a374a8131519c0f7422.tar.bz2 |
Merge tag 'asm-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic fixes from Arnd Bergmann:
"I have one regression fix for a minor build problem after the
architecture removal series, plus a rework of the barriers in the
readl/writel functions, thanks to work by Sinan Kaya:
This started from a discussion on the linuxpcc and rdma mailing
lists[1]. To summarize, we decided that architectures are responsible
to serialize readl() and writel() accesses on a device MMIO space
relative to DMA performed by that device.
This series provides a pessimistic implementation of that behavior for
asm-generic/io.h, which is in turn used by a number of architectures
(h8300, microblaze, nios2, openrisc, s390, sparc, um, unicore32, and
xtensa). Some of those presumably need no extra barriers, or something
weaker than rmb()/wmb(), and they are advised to override the new
default for better performance.
For inb()/outb(), the same barriers are used, but architectures might
want to add another barrier to outb() here if that can guarantee
non-posted behavior (some architectures can, others cannot do that).
The readl_relaxed()/writel_relaxed() family of functions retains the
existing behavior with no extra barriers"
[1] https://lists.ozlabs.org/pipermail/linuxppc-dev/2018-March/170481.html
* tag 'asm-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
io: change writeX_relaxed() to remove barriers
io: change readX_relaxed() to remove barriers
dts: remove cris & metag dts hard link file
io: change inX() to have their own IO barrier overrides
io: change outX() to have their own IO barrier overrides
io: define stronger ordering for the default writeX() implementation
io: define stronger ordering for the default readX() implementation
io: define several IO & PIO barrier types for the asm-generic version
Diffstat (limited to 'scripts/dtc/libfdt/fdt.c')
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