The hardware supports transfers up to a page boundary per buffer.
Currently, we work around that in the DMA code by splitting each
buffer up as we run through the scatterlist. Avoid this by telling
the block layers about the hardware restriction.
Eventually, this will allow us to phase out the splitting code,
but not until the old IDE layer allows us to control the value it
gives to blk_queue_segment_boundary().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that the IOMD DMA code walks the scatterlist using sg_next,
converting the sg list into a contiguous list is no longer required.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Separate the RiscPC specific (IOMD and floppy FIQ) data out of the core
DMA structure by making the IOMD and floppy DMA supersets.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than having the central DMA multiplexer call the architecture
specific DMA initialization function, have each architecture DMA
initialization function use core_initcall(), and register each DMA
channel separately with the multiplexer.
This removes the array of dma structures in the central multiplexer,
replacing it with an array of pointers instead; this is more flexible
since it allows the drivers to wrap the DMA structure (eventually
allowing us to transition non-ISA DMA drivers away.)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This is a preparitory patch to allow us to easily change the way we
add and lookup DMA channel structures.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When ISA_DMA_API is unset, we're not implementing the ISA DMA API,
so there's no point in publishing the prototypes via asm/dma.h, nor
including the machine dependent parts of that API.
This allows us to remove a lot of mach/dma.h files which don't contain
any useful code. Unfortunately though, some platforms put their own
private non-ISA definitions into mach/dma.h, so we leave these behind
and fix the appropriate #include statments.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since 8d5796d2ec, we have allowed
PAGE_OFFSET to be configurable, so a constant virtual address
for MAX_DMA_ADDRESS is buggy. It should be defined in terms of
PAGE_OFFSET rather than a constant virtual address.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move the definition of MAX_DMA_ADDRESS from mach/dma.h to mach/memory.h,
thereby placing it along side its relative, ISA_DMA_THRESHOLD.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
mach/io.h doesn't need linux/mm.h.
mach/dma.h doesn't need linux/device.h, asm/page.h or mach/hardware.h
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ixp23xx's mach/io.h claims to need linux/kernel.h for BUG().
However, this header doesn't make use of BUG().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h in mach/timex.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h in mach/io.h, mach/memory.h and mach/timex.h. Include
this header file where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h in mach/io.h. Include this header file where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h in mach/io.h. Include this header file where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h in mach/io.h. Include this header file where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h in mach/io.h. Include this header file where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h in mach/io.h. Include this header file where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h in mach/io.h. Include this header file where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h in mach/io.h. Include this header file where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h in mach/io.h. Include this header file where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid unnecessarily pollution of the kernel's namespace by avoiding
mach/hardware.h. Include this header file where necessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Let's provide an overridable default instead of having every machine
class define __virt_to_bus and __bus_to_virt to the same thing. What
most platforms are using is bus_addr == phys_addr so such is the default.
One exception is ebsa110 which has no DMA what so ever, so the actual
definition is not important except only for proper compilation. Also
added a comment about the special footbridge bus translation.
Let's also remove comments alluding to set_dma_addr which is not
(and should not) be commonly used.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There is no machine class overriding this. If non linear translations
are implemented again for some machines then this could be restored at
that time.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The restriction on !CONFIG_HIGHMEM is unneeded since page tables are
currently never allocated with highmem pages, and actually disable PTE
dump whenever highmem is configured. Let's have a dynamic test to better
describe the current limitation instead.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit 8d5796d2ec allows for the vmalloc
area to be resized from the kernel cmdline. Make sure it cannot overlap
with RAM entirely.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Make free_area() arguments pfn based, and return number of freed pages.
This will simplify highmem initialization later.
Also, codepages, datapages and initpages are actually codesize, datasize
and initsize.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Doing so will greatly simplify the bootmem initialization code as each
bank is therefore entirely lowmem or highmem with no crossing between
those zones.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Currently there are two instances of struct meminfo: one in
kernel/setup.c marked __initdata, and another in mm/init.c with
permanent storage. Let's keep only the later to directly populate
the permanent version from arm_add_memory().
Also move common validation tests between the MMU and non-MMU cases
into arm_add_memory() to remove some duplication. Protection against
overflowing the membank array is also moved in there in order to cover
the kernel cmdline parsing path as well.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In all cases the kaddr is assigned an input register even though it is
modified in the assembly code. Let's assign a new variable to the
modified value and mark those inline asm with volatile otherwise they
get optimized away because the output variable is otherwise not used.
Also fix a few conversion errors in copypage-feroceon.c and
copypage-v4mc.c.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
For similar reasons as copy_user_page(), we want to avoid the
additional kmap_atomic if it's unnecessary.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We used to override the copy_user_page() function. However, this
is not only inefficient, it also causes additional complexity for
highmem support, since we convert from a struct page to a kernel
direct mapped address and back to a struct page again.
Moreover, with highmem support, we end up pointlessly setting up
kmap entries for pages which we're going to remap. So, push the
kmapping down into the copypage implementation files where it's
required.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
With aliasing VIPT cache support, the ARM implementation of
clear_user_page() and copy_user_page() sets up a temporary kernel space
mapping such that we have the same cache colour as the userspace page.
This avoids having to consider any userspace aliases from this operation.
However, when highmem is enabled, kmap_atomic() have to setup mappings.
The copy_user_highpage() and clear_user_highpage() call these functions
before delegating the copies to copy_user_page() and clear_user_page().
The effect of this is that each of the *_user_highpage() functions setup
their own kmap mapping, followed by the *_user_page() functions setting
up another mapping. This is rather wasteful.
Thankfully, copy_user_highpage() can be overriden by architectures by
defining __HAVE_ARCH_COPY_USER_HIGHPAGE. However, replacement of
clear_user_highpage() is more difficult because its inline definition
is not conditional. It seems that you're expected to define
__HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and provide a replacement
__alloc_zeroed_user_highpage() implementation instead.
The allocation itself is fine, so we don't want to override that. What
we really want to do is to override clear_user_highpage() with our own
version which doesn't kmap_atomic() unnecessarily.
Other VIPT architectures (PARISC and SH) would also like to override
this function as well.
Acked-by: Hugh Dickins <hugh@veritas.com>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Continuing the move away from implementations which give an excuse
for other bad implementations, convert SA1100 to lookup its singular
clock by dev_name(dev) rather than by id.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
