Commit Graph

8 Commits

Author SHA1 Message Date
Nicolas Pitre
6d3e6d3640 ARM: fix cache-feroceon-l2 after stack based kmap_atomic()
Since commit 3e4d3af501 "mm: stack based kmap_atomic()", it is actively
wrong to rely on fixed kmap type indices (namely KM_L2_CACHE) as
kmap_atomic() totally ignores them and a concurrent instance of it may
happily reuse any slot for any purpose.  Because kmap_atomic() is now
able to deal with reentrancy, we can get rid of the ad hoc mapping here.

While the code is made much simpler, there is a needless cache flush
introduced by the usage of __kunmap_atomic().  It is not clear if the
performance difference to remove that is worth the cost in code
maintenance (I don't think there are that many highmem users on that
platform anyway) but that should be reconsidered when/if someone cares
enough to do some measurements.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2010-12-19 12:57:16 -05:00
Nicolas Pitre
f000328ac1 [ARM] Kirkwood: small L2 code cleanup
Strictly speaking, a MCR instruction does not produce any output.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
2009-03-28 22:39:30 -04:00
Maxime Bizon
d75de08727 [ARM] Kirkwood: invalidate L2 cache before enabling it
I get random oopses on my Kirkwood board at startup when L2 cache is
enabled. FYI I'm using Marvell uboot version 3.4.16

Each boot produces the same oops, but anything that changes the kernel
size (even only changing initramfs) makes the oops different.

I noticed that nothing invalidates the L2 cache before enabling it,
doing so fixes my problem.

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
2009-03-28 22:39:30 -04:00
Nicolas Pitre
1bb772679f [ARM] Feroceon: add highmem support to L2 cache handling code
The choice is between looping over the physical range and performing
single cache line operations, or to map highmem pages somewhere, as
cache range ops are possible only on virtual addresses.

Because L2 range ops are much faster, we go with the later by factoring
the physical-to-virtual address conversion and use a fixmap entry for it
in the HIGHMEM case.

Possible future optimizations to avoid the pte setup cost:

 - do the pte setup for highmem pages only

 - determine a threshold for doing a line-by-line processing on physical
   addresses when the range is small

Signed-off-by: Nicolas Pitre <nico@marvell.com>
2009-03-15 21:01:21 -04:00
Nicolas Pitre
72bc2b1ad6 [ARM] 5329/1: Feroceon: fix feroceon_l2_inv_range
Same fix as commit c7cf72dcad: when 'start' and 'end' are less than a
cacheline apart and 'start' is unaligned we are done after cleaning and
invalidating the first cacheline.

Cc: <stable@kernel.org>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-11-08 23:08:54 +00:00
Nicolas Pitre
99c6bb390c [ARM] Feroceon: small cleanups to L2 cache code
- Make sure that coprocessor instructions for range ops are contiguous
  and not reordered.

- s/invalidate_and_disable_dcache/flush_and_disable_dcache/

- Don't re-enable I/D caches if they were not enabled initially.

- Change some masks to shifts for better generated code.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Acked-by: Lennert Buytenhek <buytenh@marvell.com>
2008-09-30 13:41:54 -04:00
Lennert Buytenhek
6f088f1d21 [ARM] Move include/asm-arm/plat-orion to arch/arm/plat-orion/include/plat
This patch performs the equivalent include directory shuffle for
plat-orion, and fixes up all users.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
2008-08-09 13:44:58 +02:00
Lennert Buytenhek
99c6dc117d [ARM] Feroceon: L2 cache support
This patch adds support for the unified Feroceon L2 cache controller
as found in e.g. the Marvell Kirkwood and Marvell Discovery Duo
families of ARM SoCs.

Note that:

- Page table walks are outer uncacheable on Kirkwood and Discovery
  Duo, since the ARMv5 spec provides no way to indicate outer
  cacheability of page table walks (specifying it in TTBR[4:3] is
  an ARMv6+ feature).

  This requires adding L2 cache clean instructions to
  proc-feroceon.S (dcache_clean_area(), set_pte()) as well as to
  tlbflush.h ({flush,clean}_pmd_entry()).  The latter case is handled
  by defining a new TLB type (TLB_FEROCEON) which is almost identical
  to the v4wbi one but provides a TLB_L2CLEAN_FR flag.

- The Feroceon L2 cache controller supports L2 range (i.e. 'clean L2
  range by MVA' and 'invalidate L2 range by MVA') operations, and this
  patch uses those range operations for all Linux outer cache
  operations, as they are faster than the regular per-line operations.

  L2 range operations are not interruptible on this hardware, which
  avoids potential livelock issues, but can be bad for interrupt
  latency, so there is a compile-time tunable (MAX_RANGE_SIZE) which
  allows you to select the maximum range size to operate on at once.
  (Valid range is between one cache line and one 4KiB page, and must
  be a multiple of the line size.)

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
2008-06-22 22:45:04 +02:00