Commit 4da9484b authored Apr 06, 2011 by H. Peter Anvin

x86, hibernate: Initialize mmu_cr4_features during boot



Restore the initialization of mmu_cr4_features during boot, which was
removed without comment in checkin e5f15b45

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>

parent 765af22d

arch/x86/kernel/setup.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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,