Commit Graph

5 Commits

Author SHA1 Message Date
Russell King
0560cf5aa5 [ARM] Add a common typesafe __io implementation
As Al did for Versatile in 2ad4f86b60,
add a typesafe __io implementation for platforms to use.  Convert
platforms to use this new simple typesafe implementation.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-11-30 11:45:54 +00:00
Russell King
db5b716947 [ARM] Remove MT_DEVICE_IXP2000 and associated definitions
As of the previous commit, MT_DEVICE_IXP2000 encodes to the same
PTE bit encoding as MT_DEVICE, so it's now redundant.  Convert
MT_DEVICE_IXP2000 to use MT_DEVICE instead, and remove its aliases.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-10-01 16:41:06 +01:00
Lennert Buytenhek
1ad77a876d [ARM] 5241/1: provide ioremap_wc()
This patch provides an ARM implementation of ioremap_wc().

We use different page table attributes depending on which CPU we
are running on:

- Non-XScale ARMv5 and earlier systems: The ARMv5 ARM documents four
  possible mapping types (CB=00/01/10/11).  We can't use any of the
  cached memory types (CB=10/11), since that breaks coherency with
  peripheral devices.  Both CB=00 and CB=01 are suitable for _wc, and
  CB=01 (Uncached/Buffered) allows the hardware more freedom than
  CB=00, so we'll use that.

  (The ARMv5 ARM seems to suggest that CB=01 is allowed to delay stores
  but isn't allowed to merge them, but there is no other mapping type
  we can use that allows the hardware to delay and merge stores, so
  we'll go with CB=01.)

- XScale v1/v2 (ARMv5): same as the ARMv5 case above, with the slight
  difference that on these platforms, CB=01 actually _does_ allow
  merging stores.  (If you want noncoalescing bufferable behavior
  on Xscale v1/v2, you need to use XCB=101.)

- Xscale v3 (ARMv5) and ARMv6+: on these systems, we use TEXCB=00100
  mappings (Inner/Outer Uncacheable in xsc3 parlance, Uncached Normal
  in ARMv6 parlance).

  The ARMv6 ARM explicitly says that any accesses to Normal memory can
  be merged, which makes Normal memory more suitable for _wc mappings
  than Device or Strongly Ordered memory, as the latter two mapping
  types are guaranteed to maintain transaction number, size and order.
  We use the Uncached variety of Normal mappings for the same reason
  that we can't use C=1 mappings on ARMv5.

  The xsc3 Architecture Specification documents TEXCB=00100 as being
  Uncacheable and allowing coalescing of writes, which is also just
  what we need.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-06 13:13:44 +01:00
Russell King
a09e64fbc0 [ARM] Move include/asm-arm/arch-* to arch/arm/*/include/mach
This just leaves include/asm-arm/plat-* to deal with.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-07 09:55:48 +01:00
Russell King
4baa992243 [ARM] move include/asm-arm to arch/arm/include/asm
Move platform independent header files to arch/arm/include/asm, leaving
those in asm/arch* and asm/plat* alone.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-02 21:32:35 +01:00