From f361a450bf1ad14e2b003217dbf3958638631265 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Thu, 10 Jul 2008 20:38:26 -0700 Subject: x86: introduce max_low_pfn_mapped for 64-bit when more than 4g memory is installed, don't map the big hole below 4g. Signed-off-by: Yinghai Lu Cc: Suresh Siddha Signed-off-by: Ingo Molnar --- arch/x86/kernel/e820.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/e820.c') diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 3451e0b3f32..9f5002e0b35 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -1056,7 +1056,7 @@ unsigned long __initdata end_user_pfn = MAX_ARCH_PFN; /* * Find the highest page frame number we have available */ -unsigned long __init e820_end(void) +static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type) { int i; unsigned long last_pfn = 0; @@ -1064,12 +1064,21 @@ unsigned long __init e820_end(void) for (i = 0; i < e820.nr_map; i++) { struct e820entry *ei = &e820.map[i]; + unsigned long start_pfn; unsigned long end_pfn; - if (ei->type != E820_RAM) + if (ei->type != type) continue; + start_pfn = ei->addr >> PAGE_SHIFT; end_pfn = (ei->addr + ei->size) >> PAGE_SHIFT; + + if (start_pfn >= limit_pfn) + continue; + if (end_pfn > limit_pfn) { + last_pfn = limit_pfn; + break; + } if (end_pfn > last_pfn) last_pfn = end_pfn; } @@ -1083,7 +1092,15 @@ unsigned long __init e820_end(void) last_pfn, max_arch_pfn); return last_pfn; } +unsigned long __init e820_end_of_ram_pfn(void) +{ + return e820_end_pfn(MAX_ARCH_PFN, E820_RAM); +} +unsigned long __init e820_end_of_low_ram_pfn(void) +{ + return e820_end_pfn(1UL<<(32 - PAGE_SHIFT), E820_RAM); +} /* * Finds an active region in the address range from start_pfn to last_pfn and * returns its range in ei_startpfn and ei_endpfn for the e820 entry. @@ -1206,7 +1223,7 @@ static int __init parse_memmap_opt(char *p) * the real mem size before original memory map is * reset. */ - saved_max_pfn = e820_end(); + saved_max_pfn = e820_end_of_ram_pfn(); #endif e820.nr_map = 0; userdef = 1; -- cgit v1.2.3