Messages in this thread Patch in this message | | | Date | Wed, 6 Apr 2011 20:28:00 GMT | From | "tip-bot for H. Peter Anvin" <> | Subject | [tip:x86/urgent] x86, hibernate: Initialize mmu_cr4_features during boot |
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Commit-ID: 4da9484bdece39ab0b098fa711e095e3e9fc8684 Gitweb: http://git.kernel.org/tip/4da9484bdece39ab0b098fa711e095e3e9fc8684 Author: H. Peter Anvin <hpa@linux.intel.com> AuthorDate: Wed, 6 Apr 2011 13:10:02 -0700 Committer: H. Peter Anvin <hpa@linux.intel.com> CommitDate: Wed, 6 Apr 2011 13:10:02 -0700
x86, hibernate: Initialize mmu_cr4_features during boot
Restore the initialization of mmu_cr4_features during boot, which was removed without comment in checkin e5f15b45ddf3afa2bbbb10c7ea34fb32b6de0a0e
x86: Cleanup highmap after brk is concluded
thereby breaking resume from hibernate. This restores previous functionality in approximately the same place, and corrects the reading of %cr4 on pre-CPUID hardware (%cr4 exists if and only if CPUID is supported.)
However, part of the problem is that the hibernate suspend/resume sequence should manage the save/restore of %cr4 explicitly.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <201104020154.57136.rjw@sisk.pl> --- arch/x86/kernel/setup.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 5a0484a..4be9b39 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -976,6 +976,11 @@ void __init setup_arch(char **cmdline_p) paging_init(); x86_init.paging.pagetable_setup_done(swapper_pg_dir); + if (boot_cpu_data.cpuid_level >= 0) { + /* A CPU has %cr4 if and only if it has CPUID */ + mmu_cr4_features = read_cr4(); + } + #ifdef CONFIG_X86_32 /* sync back kernel address range */ clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
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