Since 'commit 9cd25aac1f44 ("x86/mm/pat: Emulate PAT when it
is disabled")', we emulate a PAT table when PAT is disabled.
This requires pat_init() be called even if PAT is disabled,
which revealed a long standing issue that PAT is left enabled
without calling pat_init() at all.pat_init() is called from MTRR code since it relies on MTRR's rendezvous handler to initialize PAT for all APs . However, when CPU does not support MTRR, ex. qemu32's virtual CPU, MTRR is set disabled and does not call pat_init(). There is no interface available for MTRR to disable PAT, either. This patch-set refactors MTRR and PAT initializations to make sure that PAT is properly initialized in all cases. --- Toshi Kani (2): 1/2 x86/mm/pat: Change pat_disable() to emulate PAT table 2/2 x86/mtrr: Refactor PAT initialization code --- arch/x86/include/asm/mtrr.h | 6 ++- arch/x86/include/asm/pat.h | 1 + arch/x86/kernel/cpu/mtrr/generic.c | 24 ++++++----- arch/x86/kernel/cpu/mtrr/main.c | 13 +++++- arch/x86/kernel/cpu/mtrr/mtrr.h | 1 + arch/x86/mm/pat.c | 84 +++++++++++++++++++++++--------------- 6 files changed, 84 insertions(+), 45 deletions(-)
