linux/arch/powerpc
Arnd Bergmann cc4b7c1814 [POWERPC] spufs: invalidate SLB translation before adding a new entry
When we replace an SLB entry in the MFC after using up all the available
entries, there is a short window in which an incorrect entry is marked
as valid.

The problem is that the 'valid' bit is stored in the ESID, which is
always written after the VSID. Overwriting the VSID first will make the
original ESID entry point to the new VSID, which means that any
concurrent DMA accessing the old ESID ends up being redirected to the
new virtual address.  A few cycles later, we write the new ESID and
everything is fine again.

That race can be closed by writing a zero entry to the ESID first, which
makes sure that the VSID is not accessed until we write the new ESID.

Note that we don't actually need to invalidate the SLB entry using the
invalidation register, which would also flush any ERAT entries for that
segment, because the segment translation does not become invalid but is
only removed from the SLB cache.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
2008-02-29 15:17:49 +11:00
..
boot [POWERPC] Remove generated files on make clean 2008-02-14 22:11:02 +11:00
configs [POWERPC] 83xx: Update mpc83xx_defconfig 2008-02-05 23:48:06 -06:00
kernel [POWERPC] vdso_do_func_patch{32,64}() must be __init 2008-02-14 22:11:02 +11:00
lib [POWERPC] rheap: Changes config mechanism 2007-10-16 17:09:21 -06:00
math-emu [POWERPC] Fix carry bug in 128-bit unsigned integer adding 2008-01-23 19:34:21 -06:00
mm Merge branch 'for-2.6.25' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc 2008-02-08 09:31:42 -08:00
oprofile d_path: Make get_dcookie() use a struct path argument 2008-02-14 21:17:08 -08:00
platforms [POWERPC] spufs: invalidate SLB translation before adding a new entry 2008-02-29 15:17:49 +11:00
sysdev [POWERPC] Add missing native dcr dcr_ind_lock spinlock 2008-02-06 21:02:56 -06:00
xmon [POWERPC] Make setjmp/longjmp code usable outside of xmon 2008-01-25 22:52:50 +11:00
.gitignore [POWERPC] Add files build to .gitignore 2006-12-04 20:41:29 +11:00
Kconfig [POWERPC] Remove unused CONFIG_WANT_DEVICE_TREE 2008-02-14 22:11:03 +11:00
Kconfig.debug [POWERPC] 4xx: Base support for 440GX Taishan eval board 2007-12-23 13:13:33 -06:00
Makefile [POWERPC] bootwrapper: Build multiple cuImages 2008-02-07 11:40:19 +11:00