linux/arch
Paul Mackerras 65ba6cdc83 [POWERPC] Clear sub-page HPTE present bits when demoting page size
When we demote a slice from 64k to 4k, and we are about to insert an
HPTE for a 4k subpage and we notice that there is an existing 64k
HPTE, we first invalidate that HPTE before inserting the new 4k
subpage HPTE.  Since the bits that encode which hash bucket the old
HPTE was in overlap with the bits that encode which of the 16 subpages
have HPTEs, we need to clear out the subpage HPTE-present bits before
starting to insert HPTEs for the 4k subpages.  If we don't do that, we
can erroneously think that a subpage already has an HPTE when it
doesn't.

That in itself wouldn't be such a problem except that when we go to
update the HPTE that we think is present on machines with a
hypervisor, the hypervisor can tell us that the HPTE we think is there
is actually there even though it isn't, which can lead to a process
getting stuck in a loop, continually faulting.  The reason for the
confusion is that the AVPN (abbreviated virtual page number) we are
looking for in the HPTE for a 4k subpage can actually match the AVPN
in a stale HPTE for another 64k page.  For example, the HPTE for
the 4k subpage at 0x84000f000 will be in the same hash bucket and have
the same AVPN as the HPTE for the 64k page at 0x8400f0000.

This fixes the code to clear out the subpage HPTE-present bits.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-18 21:40:43 +10:00
..
alpha [PATCH] take init_files to fs/file.c 2008-05-16 17:22:20 -04:00
arm [ARM] 5077/1: spi: fix list scan success verification in PXA ssp driver 2008-06-11 23:38:46 +01:00
avr32 avr32: Fix cpufreq oops when ondemand governor is default 2008-05-27 09:37:42 +02:00
blackfin Blackfin arch: protect only the SPI bus controller with CONFIG_SPI_BFIN 2008-06-07 15:03:01 +08:00
cris [PATCH] take init_files to fs/file.c 2008-05-16 17:22:20 -04:00
frv Fix various old email addresses for dwmw2 2008-06-06 11:29:10 -07:00
h8300 [PATCH] take init_files to fs/file.c 2008-05-16 17:22:20 -04:00
ia64 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 2008-06-16 11:52:43 -07:00
m32r [PATCH] take init_files to fs/file.c 2008-05-16 17:22:20 -04:00
m68k m68k: enable CONFIG_COMPAT_BRK by default 2008-06-06 11:29:09 -07:00
m68knommu m68knommu: init coldfire timer TRR with n - 1, not n 2008-06-12 18:05:40 -07:00
mips [MIPS] Au1200: MMC resource size off by one 2008-06-16 15:14:49 +01:00
mn10300 MN10300: Kill linux/a.out.h inclusions 2008-06-16 10:20:57 -07:00
parisc parisc: fix off by one in setup_sigcontext32 2008-06-13 10:49:55 -04:00
powerpc [POWERPC] Clear sub-page HPTE present bits when demoting page size 2008-06-18 21:40:43 +10:00
ppc [POWERPC] Export empty_zero_page and copy_page in arch/ppc 2008-05-31 17:08:28 +10:00
s390 Merge branch 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm 2008-06-11 10:35:44 -07:00
sh sh: Add -mno-fdpic to default flags. 2008-06-09 16:49:43 +09:00
sparc sparc: switch /proc/led to seq_file 2008-06-03 15:21:21 -07:00
sparc64 sparc64: Prevent stack backtrace false positives on trap frames. 2008-05-21 21:50:01 -07:00
um uml: work around broken host PTRACE_SYSEMU 2008-06-12 18:05:40 -07:00
v850 [PATCH] take init_files to fs/file.c 2008-05-16 17:22:20 -04:00
x86 x86-64: Fix "bytes left to copy" return value for copy_from_user() 2008-06-17 17:47:50 -07:00
xtensa [PATCH] take init_files to fs/file.c 2008-05-16 17:22:20 -04:00
.gitignore
Kconfig dma: add dma_*map*_attrs() interfaces 2008-04-29 08:06:11 -07:00