Alpha implements custom SHIFT_PERCPU_PTR for modules because percpu
area can be located far away from the 4G area where the module text is
located. The custom SHIFT_PERCPU_PTR forces GOT usage using ldq
instruction with literal relocation; however, the relocation can't be
used with dynamically allocated percpu variables. Fortunately,
similar result can be achieved by using weak percpu variable
definitions.
This patch makes alpha use weak definitions and switch to dynamic
percpu allocator.
asm/tlbflush.h was getting linux/sched.h via asm/percpu.h which no
longer needs it. Include linux/sched.h directly in asm/tlbflush.h.
Compile tested. Generation of litereal relocation verified.
This patch is based on Ivan Kokshaysky's alpha percpu patch.
[ Impact: use dynamic percpu allocator ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
With the previous percpu variable definition change, all percpu
variables are global and there's no need to specify __used, which only
triggers on recent compilers anyway. Kill it.
[ Impact: remove unnecessary percpu attribute ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Commit 9b8de7479d ("FRV: Fix the section
attribute on UP DECLARE_PER_CPU()") cleaned up DECLARE/DEFINE_PER_CPU()
macros and in the process made alpha percpu.h include
include/asm-generic/percpu.h which breaks compilation due to duplicate
definitions.
Remove inclusion of generic asm helper file and define whatever necessary
in alpha header proper.
In the longer term, percpu definitions will be unified and all these
little subtlties will be removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: David Howells <dhowells@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In non-SMP mode, the variable section attribute specified by DECLARE_PER_CPU()
does not agree with that specified by DEFINE_PER_CPU(). This means that
architectures that have a small data section references relative to a base
register may throw up linkage errors due to too great a displacement between
where the base register points and the per-CPU variable.
On FRV, the .h declaration says that the variable is in the .sdata section, but
the .c definition says it's actually in the .data section. The linker throws
up the following errors:
kernel/built-in.o: In function `release_task':
kernel/exit.c:78: relocation truncated to fit: R_FRV_GPREL12 against symbol `per_cpu__process_counts' defined in .data section in kernel/built-in.o
kernel/exit.c:78: relocation truncated to fit: R_FRV_GPREL12 against symbol `per_cpu__process_counts' defined in .data section in kernel/built-in.o
To fix this, DECLARE_PER_CPU() should simply apply the same section attribute
as does DEFINE_PER_CPU(). However, this is made slightly more complex by
virtue of the fact that there are several variants on DEFINE, so these need to
be matched by variants on DECLARE.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sam Ravnborg did the build-test that the direct header file move works,
I'm just committing it.
This is a pure move:
mkdir arch/alpha/include
git mv include/asm-alpha arch/alpha/include/asm
with no other changes.
Requested-and-tested-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-15 09:19:40 -07:00
Renamed from include/asm-alpha/percpu.h (Browse further)
