lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [day] [month] [year] [list]
Message-Id: <1213916210.27983.32.camel@promb-2n-dhcp368.eng.vmware.com>
Date:	Thu, 19 Jun 2008 15:56:49 -0700
From:	Alok Kataria <akataria@...are.com>
To:	"Brown, Len" <len.brown@...el.com>,
	Andrew Morton <akpm@...ux-foundation.org>
Cc:	LKML <linux-kernel@...r.kernel.org>, linux-acpi@...r.kernel.org
Subject: [PCI_ACPI] Modify PCI gap calculation

Today, we calculate a gap in the low 32bit address space for PCI devices
to assign MMIO resources for hotplug or unconfigured devices,
(pci_mem_start). 
This gap calculation is done by walking the e820 memory space, this
calculation ignores the SRAT for any possible reservations that the
BIOS might have done for memory hotplug. In some cases the
PCI device resources (f.e. Expansion ROMS) end up sharing the address
space with memory hotplug capable regions. 

As a result, when we try to hotadd memory to a system which has less
than 4GB memory to start with, we see resource clashes and the hotadd
requests fail. 

The solution here is to find a PCI gap in the PCI reserved regions as
exported by the ACPI table. We read the _CRS object under PCI0 for
possible producer regions and search for a big enough unclaimed gap
within these producer regions.

There are 2 patches 
1. cleanup of the e820_search_gap function
2. code which walks ACPI resources searching for gap within producer
regions.

I have kept the original e820_find_gap function since in systems with
ACPI disabled we still may need to calculate the gap.

Please have a look. 

Thanks,
Alok

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ