WSL2-Linux-Kernel/arch/x86/platform
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
..
ce4100 arch/x86/platform/ce4100/ce4100.c: include reboot.h 2013-07-31 14:41:02 -07:00
efi x86, efi: Don't map Boot Services on i386 2013-09-18 14:42:33 +01:00
geode arch/x86/platform/geode/net5501.c: change active_low to 0 for LED driver 2012-05-04 14:40:07 -07:00
goldfish goldfish: platform device for x86 2013-01-21 12:09:19 -08:00
iris arch/x86/platform/iris/iris.c: register a platform device and a platform driver 2012-12-18 15:02:11 -08:00
mrst gpio: (gpio-pca953x) move header to linux/platform_data/ 2013-08-29 12:33:52 -07:00
olpc x86/olpc/xo1/sci: Don't call input_free_device() after input_unregister_device() 2013-04-24 08:44:47 +02:00
scx200 X86: drivers: remove __dev* attributes. 2013-01-03 15:57:04 -08:00
sfi x86: Convert a few mistaken __cpuinit annotations to __init 2013-01-24 17:12:19 +01:00
ts5500 x86: Add TS-5500 platform support 2013-01-25 19:40:23 +01:00
uv x86/platform/uv: Replace kmalloc() & memset with kzalloc() 2013-03-11 08:33:01 +01:00
visws x86/apic: Fix typo EIO_ACK -> EOI_ACK and document it 2012-05-18 09:46:07 +02:00
Makefile x86: Add TS-5500 platform support 2013-01-25 19:40:23 +01:00