linux/arch
Josh Boyer 700870119f x86, efi: Don't map Boot Services on i386
Add patch to fix 32bit EFI service mapping (rhbz 726701)

Multiple people are reporting hitting the following WARNING on i386,

  WARNING: at arch/x86/mm/ioremap.c:102 __ioremap_caller+0x3d3/0x440()
  Modules linked in:
  Pid: 0, comm: swapper Not tainted 3.9.0-rc7+ #95
  Call Trace:
   [<c102b6af>] warn_slowpath_common+0x5f/0x80
   [<c1023fb3>] ? __ioremap_caller+0x3d3/0x440
   [<c1023fb3>] ? __ioremap_caller+0x3d3/0x440
   [<c102b6ed>] warn_slowpath_null+0x1d/0x20
   [<c1023fb3>] __ioremap_caller+0x3d3/0x440
   [<c106007b>] ? get_usage_chars+0xfb/0x110
   [<c102d937>] ? vprintk_emit+0x147/0x480
   [<c1418593>] ? efi_enter_virtual_mode+0x1e4/0x3de
   [<c102406a>] ioremap_cache+0x1a/0x20
   [<c1418593>] ? efi_enter_virtual_mode+0x1e4/0x3de
   [<c1418593>] efi_enter_virtual_mode+0x1e4/0x3de
   [<c1407984>] start_kernel+0x286/0x2f4
   [<c1407535>] ? repair_env_string+0x51/0x51
   [<c1407362>] i386_start_kernel+0x12c/0x12f

Due to the workaround described in commit 916f676f8 ("x86, efi: Retain
boot service code until after switching to virtual mode") EFI Boot
Service regions are mapped for a period during boot. Unfortunately, with
the limited size of the i386 direct kernel map it's possible that some
of the Boot Service regions will not be directly accessible, which
causes them to be ioremap()'d, triggering the above warning as the
regions are marked as E820_RAM in the e820 memmap.

There are currently only two situations where we need to map EFI Boot
Service regions,

  1. To workaround the firmware bug described in 916f676f8
  2. To access the ACPI BGRT image

but since we haven't seen an i386 implementation that requires either,
this simple fix should suffice for now.

[ Added to changelog - Matt ]

Reported-by: Bryan O'Donoghue <bryan.odonoghue.lkml@nexus-software.ie>
Acked-by: Tom Zanussi <tom.zanussi@intel.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2013-09-18 14:42:33 +01:00
..
alpha Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
arc Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
arm Merge branch 'timers/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-09-16 16:10:26 -04:00
arm64 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
avr32 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
blackfin Merge branch 'genirq' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2013-09-13 07:31:38 -07:00
c6x Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
cris Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
frv Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
h8300 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
hexagon Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
ia64 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
m32r Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
m68k Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
metag Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
microblaze Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
mips Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2013-09-15 17:45:52 -04:00
mn10300 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
openrisc Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
parisc Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
powerpc Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
s390 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
score Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
sh Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
sparc Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
tile Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
um Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
unicore32 Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
x86 x86, efi: Don't map Boot Services on i386 2013-09-18 14:42:33 +01:00
xtensa Xtensa patchset for v3.12 2013-09-13 10:57:48 -07:00
.gitignore
Kconfig microblaze: fix clone syscall 2013-08-13 17:57:48 -07:00