linux/arch
Maciej W. Rozycki 593f4a788e x86: APIC: remove apic_write_around(); use alternatives
Use alternatives to select the workaround for the 11AP Pentium erratum
for the affected steppings on the fly rather than build time.  Remove the
X86_GOOD_APIC configuration option and replace all the calls to
apic_write_around() with plain apic_write(), protecting accesses to the
ESR as appropriate due to the 3AP Pentium erratum.  Remove
apic_read_around() and all its invocations altogether as not needed.
Remove apic_write_atomic() and all its implementing backends.  The use of
ASM_OUTPUT2() is not strictly needed for input constraints, but I have
used it for readability's sake.

I had the feeling no one else was brave enough to do it, so I went ahead
and here it is.  Verified by checking the generated assembly and tested
with both a 32-bit and a 64-bit configuration, also with the 11AP
"feature" forced on and verified with gdb on /proc/kcore to work as
expected (as an 11AP machines are quite hard to get hands on these days).
Some script complained about the use of "volatile", but apic_write() needs
it for the same reason and is effectively a replacement for writel(), so I
have disregarded it.

I am not sure what the policy wrt defconfig files is, they are generated
and there is risk of a conflict resulting from an unrelated change, so I
have left changes to them out.  The option will get removed from them at
the next run.

Some testing with machines other than mine will be needed to avoid some
stupid mistake, but despite its volume, the change is not really that
intrusive, so I am fairly confident that because it works for me, it will
everywhere.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 12:51:21 +02:00
..
alpha Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
arm Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
avr32 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc 2008-07-16 15:17:52 -07:00
blackfin Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
cris Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
frv
h8300
ia64 fix build error of arch/ia64/kvm/* 2008-07-17 09:16:31 -07:00
m32r
m68k Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
m68knommu Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
mips Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
mn10300
parisc Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
powerpc powerpc/ep8248e: Fix compile problem if !CONFIG_FS_ENET 2008-07-16 11:43:48 -07:00
s390 [S390] Fix stacktrace compile bug. 2008-07-17 17:22:09 +02:00
sh Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
sparc Merge commit 'v2.6.26' into bkl-removal 2008-07-14 15:29:34 -06:00
sparc64 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
um Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
v850
x86 x86: APIC: remove apic_write_around(); use alternatives 2008-07-18 12:51:21 +02:00
xtensa
.gitignore
Kconfig