Converting an address between cached & uncached (typically addresses in
(c)kseg0 & (c)kseg1 or 2 xkphys regions) should not depend upon
PHYS_OFFSET in any way - we're converting from a virtual address in one
unmapped region to a virtual address in another unmapped region.
For some reason our CAC_ADDR() & UNCAC_ADDR() macros make use of
PAGE_OFFSET, which typically includes PHYS_OFFSET. This means that
platforms with a non-zero PHYS_OFFSET typically have to workaround
miscalculation by these 2 macros by also defining UNCAC_BASE to a value
that isn't really correct.
It appears that an attempt has previously been made to address this with
commit 3f4579252aa1 ("MIPS: make CAC_ADDR and UNCAC_ADDR account for
PHYS_OFFSET") which was later undone by commit ed3ce16c3d ("Revert
"MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET"") which
also introduced the ar7 workaround. That attempt at a fix was roughly
equivalent, but essentially caused the CAC_ADDR() & UNCAC_ADDR() macros
to cancel out PHYS_OFFSET by adding & then subtracting it again. In his
revert Leonid is correct that using PHYS_OFFSET makes no sense in the
context of these macros, but appears to have missed its inclusion via
PAGE_OFFSET which means PHYS_OFFSET actually had an effect after the
revert rather than before it.
Here we fix this by modifying CAC_ADDR() & UNCAC_ADDR() to stop using
PAGE_OFFSET (& thus PHYS_OFFSET), instead using __pa() & __va() along
with UNCAC_BASE.
For UNCAC_ADDR(), __pa() will convert a cached address to a physical
address which we can simply use as an offset from UNCAC_BASE to obtain
an address in the uncached region.
For CAC_ADDR() we can undo the effect of UNCAC_ADDR() by subtracting
UNCAC_BASE and using __va() on the result.
With this change made, remove definitions of UNCAC_BASE from the ar7 &
pic32 platforms which appear to have defined them only to workaround
this problem.
Signed-off-by: Paul Burton <paul.burton@mips.com>
References: 3f4579252aa1 ("MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET")
References: ed3ce16c3d ("Revert "MIPS: make CAC_ADDR and UNCAC_ADDR account for PHYS_OFFSET"")
Patchwork: https://patchwork.linux-mips.org/patch/20046/
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
Convert everything not overriding dma-coherence.h to the generic
noncoherent ops. The new dma-noncoherent.c file duplicates a lot of
the code in dma-default.c, but that file will be gone by the end of
this series.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Patchwork: https://patchwork.linux-mips.org/patch/19544/
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: iommu@lists.linux-foundation.org
Cc: linux-mips@linux-mips.org
Platforms will now have to supply a function dma_device_is_coherent which
returns if a particular device participates in the coherence domain. For
most platforms this function will always return 0 or 1.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pass struct dev pointer to dma_cache_sync()
dma_cache_sync() is ill-designed in that it does not have a struct device
pointer argument which makes proper support for systems that consist of a
mix of coherent and non-coherent DMA devices hard. Change dma_cache_sync
to take a struct device pointer as first argument and fix all its callers
to pass it.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
dma_is_consistent() is ill-designed in that it does not have a struct
device pointer argument which makes proper support for systems that consist
of a mix of coherent and non-coherent DMA devices hard. Change
dma_is_consistent to take a struct device pointer as first argument and fix
the sole caller to pass it.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Paul Burton