Commit 67e87f0a authored Oct 13, 2010 by Jeremy Fitzhardinge Committed by Ingo Molnar Oct 14, 2010

x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S



head_64.S maps up to 512 MiB, but that is not necessarity true for
other entry paths, such as Xen.

Thus, co-locate the setting of max_pfn_mapped with the code to
actually set up the page tables in head_64.S.  The 32-bit code is
already so co-located.  (The Xen code already sets max_pfn_mapped
correctly for its own use case.)

-v2:

 Yinghai fixed the following bug in this patch:

 |
 | max_pfn_mapped is in .bss section, so we need to set that
 | after bss get cleared. Without that we crash on bootup.
 |
 | That is safe because Xen does not call x86_64_start_kernel().
 |

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Fixed-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <4CB6AB24.9020504@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent fef5ba79

arch/x86/kernel/head64.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -80,6 +80,8 @@ void __init x86_64_start_kernel(char * real_mode_data)
		/* Cleanup the over mapped high alias */
		cleanup_highmap();

		max_pfn_mapped = KERNEL_IMAGE_SIZE >> PAGE_SHIFT;

		for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
		#ifdef CONFIG_EARLY_PRINTK
		set_intr_gate(i, &early_idt_handlers[i]);

arch/x86/kernel/setup.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -932,7 +932,6 @@ void __init setup_arch(char **cmdline_p)
		max_low_pfn = max_pfn;

		high_memory = (void )__va(max_pfn PAGE_SIZE - 1) + 1;
		max_pfn_mapped = KERNEL_IMAGE_SIZE >> PAGE_SHIFT;
		#endif

		/*

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