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>
Nobody uses flush_tlb_pgtables anymore, this patch removes all remaining
traces of it from all archs.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We are currently using the ARMv6 operations but need to duplicate some
of the code because of the introduction of the new CPU barrier
instructions in ARMv7.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.
This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
getting them indirectly
Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
they don't need sched.h
b) sched.h stops being dependency for significant number of files:
on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
after patch it's only 3744 (-8.3%).
Cross-compile tested on
all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
alpha alpha-up
arm
i386 i386-up i386-defconfig i386-allnoconfig
ia64 ia64-up
m68k
mips
parisc parisc-up
powerpc powerpc-up
s390 s390-up
sparc sparc-up
sparc64 sparc64-up
um-x86_64
x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig
as well as my two usual configs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The architecture specification states that TLB operations are
guaranteed to be complete only after the execution of a DSB (Data
Synchronisation Barrier, former Data Write Barrier or Drain Write
Buffer). The branch target cache invalidation is also needed. The ISB
(Instruction Synchronisation Barrier, formerly Prefetch Flush) is
needed unless there will be a return from exception before the
corresponding mapping is used (i.e. user mappings).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Daniel Jacobowitz
The ARM kernel has several uses of asm("foo%?"). %? is a GCC internal
modifier used to output conditional execution predicates. However, no
version of GCC supports conditionalizing asm statements. GCC 4.2 will
correctly expand %? to the empty string in user asms. Earlier versions may
reuse the condition from the previous instruction. In 'if (foo) asm
("bar%?");' this is somewhat likely to be right... but not reliable.
So, the only safe thing to do is to remove the uses of %?. I believe
the tlbflush.h occurances were supposed to be removed before, based
on the comment about %? not working at the top of that file.
Old versions of GCC could omit branches around user asms if the asm didn't
mark the condition codes as clobbered. This problem hasn't been seen on any
recent (3.x or 4.x) GCC, but it could theoretically happen. So, where
%? was removed a cc clobber was added.
Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch removes TLB related codes in nommu mode.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Catalin Marinas
Chapter B2.7.3 in the latest ARM ARM (with v6 information) states that
the completion of a TLB maintenance operation is only guaranteed by
the execution of a DSB (Data Syncronization Barrier, formerly Data
Write Barrier or Drain Write Buffer).
Note that a DSB is only needed in the flush_tlb_kernel_* functions
since the completion is guaranteed by a mode change (i.e. switching
back to user mode) for the flush_tlb_user_* functions.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The existing TLB flush implementations only have an effect on
the local CPU. Prefix them with local_.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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!
Lennert Buytenhek
Benjamin Herrenschmidt
Catalin Marinas
Alexey Dobriyan
Daniel Jacobowitz
David Woodhouse
Russell King
Hyok S. Choi
Linus Torvalds