Commit 5d423ccd authored May 06, 2009 by Yinghai Lu Committed by Ingo Molnar May 11, 2009

x86/pci: remove rounding quirk from e820_setup_gap()



Now that the e820 code explicitly reserves 'potentially dangerous'
free physical memory address space to protect ACPI stolen RAM,
there's no need for the rounding quirk in the PCI allocator anymore.

Also, this quirk was open-ended iteration that could end up reserving
a lot of free space and potentially breaking drivers - such as the one
reported by Yannick Roehlly <yannick.roehlly@free.fr> where there's
a PCI device with a large memory resource.

So remove it.

[ Impact: make more of the PCI hole available for assigning pci devices ]

Reported-by: Yannick Roehlly <yannick.roehlly@free.fr>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Jesse Barnes <jesse.barnes@intel.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4A01A7C8.5090701@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 45fbe3ee

arch/x86/kernel/e820.c

+3 −8

Original line number	Diff line number	Diff line
		@@ -617,7 +617,7 @@ __init int e820_search_gap(unsigned long gapstart, unsigned long gapsize,
		*/
		__init void e820_setup_gap(void)
		{
		unsigned long gapstart, gapsize, round;
		unsigned long gapstart, gapsize;
		int found;

		gapstart = 0x10000000;
		@@ -635,14 +635,9 @@ __init void e820_setup_gap(void)
		#endif

		/*
		* See how much we want to round up: start off with
		* rounding to the next 1MB area.
		* e820_reserve_resources_late protect stolen RAM already
		*/
		round = 0x100000;
		while ((gapsize >> 4) > round)
		round += round;
		/* Fun with two's complement */
		pci_mem_start = (gapstart + round) & -round;
		pci_mem_start = gapstart;

		printk(KERN_INFO
		"Allocating PCI resources starting at %lx (gap: %lx:%lx)\n",