linux/arch/x86/kernel/head.c
Tejun Heo 24aa07882b memblock, x86: Replace memblock_x86_reserve/free_range() with generic ones
Other than sanity check and debug message, the x86 specific version of
memblock reserve/free functions are simple wrappers around the generic
versions - memblock_reserve/free().

This patch adds debug messages with caller identification to the
generic versions and replaces x86 specific ones and kills them.
arch/x86/include/asm/memblock.h and arch/x86/mm/memblock.c are empty
after this change and removed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310462166-31469-14-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-07-14 11:47:53 -07:00

57 lines
1.8 KiB
C

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <asm/setup.h>
#include <asm/bios_ebda.h>
#define BIOS_LOWMEM_KILOBYTES 0x413
/*
* The BIOS places the EBDA/XBDA at the top of conventional
* memory, and usually decreases the reported amount of
* conventional memory (int 0x12) too. This also contains a
* workaround for Dell systems that neglect to reserve EBDA.
* The same workaround also avoids a problem with the AMD768MPX
* chipset: reserve a page before VGA to prevent PCI prefetch
* into it (errata #56). Usually the page is reserved anyways,
* unless you have no PS/2 mouse plugged in.
*/
void __init reserve_ebda_region(void)
{
unsigned int lowmem, ebda_addr;
/* To determine the position of the EBDA and the */
/* end of conventional memory, we need to look at */
/* the BIOS data area. In a paravirtual environment */
/* that area is absent. We'll just have to assume */
/* that the paravirt case can handle memory setup */
/* correctly, without our help. */
if (paravirt_enabled())
return;
/* end of low (conventional) memory */
lowmem = *(unsigned short *)__va(BIOS_LOWMEM_KILOBYTES);
lowmem <<= 10;
/* start of EBDA area */
ebda_addr = get_bios_ebda();
/* Fixup: bios puts an EBDA in the top 64K segment */
/* of conventional memory, but does not adjust lowmem. */
if ((lowmem - ebda_addr) <= 0x10000)
lowmem = ebda_addr;
/* Fixup: bios does not report an EBDA at all. */
/* Some old Dells seem to need 4k anyhow (bugzilla 2990) */
if ((ebda_addr == 0) && (lowmem >= 0x9f000))
lowmem = 0x9f000;
/* Paranoia: should never happen, but... */
if ((lowmem == 0) || (lowmem >= 0x100000))
lowmem = 0x9f000;
/* reserve all memory between lowmem and the 1MB mark */
memblock_reserve(lowmem, 0x100000 - lowmem);
}