Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm

Pull second set of ARM updates from Russell King:
 "This is the second set of ARM updates for this merge window.

  Contained within are changes to allow the kernel to boot in hypervisor
  mode on CPUs supporting virtualization, and cache flushing support to
  the point of inner sharable unification, which are used by the
  suspend/resume code to avoid having to do a full cache flush.

  Also included is one fix for VFP code identified by Michael Olbrich."

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: vfp: fix saving d16-d31 vfp registers on v6+ kernels
  ARM: 7549/1: HYP: fix boot on some ARM1136 cores
  ARM: 7542/1: mm: fix cache LoUIS API for xscale and feroceon
  ARM: mm: update __v7_setup() to the new LoUIS cache maintenance API
  ARM: kernel: update __cpu_disable to use cache LoUIS maintenance API
  ARM: kernel: update cpu_suspend code to use cache LoUIS operations
  ARM: mm: rename jump labels in v7_flush_dcache_all function
  ARM: mm: implement LoUIS API for cache maintenance ops
  ARM: virt: arch_timers: enable access to physical timers
  ARM: virt: Add CONFIG_ARM_VIRT_EXT option
  ARM: virt: Add boot-time diagnostics
  ARM: virt: Update documentation for hyp mode entry support
  ARM: zImage/virt: hyp mode entry support for the zImage loader
  ARM: virt: allow the kernel to be entered in HYP mode
  ARM: opcodes: add __ERET/__MSR_ELR_HYP instruction encoding

1 files changed, 21 insertions, 1 deletions

diff --git a/Documentation/arm/Booting b/Documentation/arm/Booting
index a341d87d276e..0c1f475fdf36 100644
--- a/Documentation/arm/Booting
+++ b/Documentation/arm/Booting
@@ -154,13 +154,33 @@ In either case, the following conditions must be met:
 
 - CPU mode
   All forms of interrupts must be disabled (IRQs and FIQs)
-  The CPU must be in SVC mode.  (A special exception exists for Angel)
+
+  For CPUs which do not include the ARM virtualization extensions, the
+  CPU must be in SVC mode.  (A special exception exists for Angel)
+
+  CPUs which include support for the virtualization extensions can be
+  entered in HYP mode in order to enable the kernel to make full use of
+  these extensions.  This is the recommended boot method for such CPUs,
+  unless the virtualisations are already in use by a pre-installed
+  hypervisor.
+
+  If the kernel is not entered in HYP mode for any reason, it must be
+  entered in SVC mode.
 
 - Caches, MMUs
   The MMU must be off.
   Instruction cache may be on or off.
   Data cache must be off.
 
+  If the kernel is entered in HYP mode, the above requirements apply to
+  the HYP mode configuration in addition to the ordinary PL1 (privileged
+  kernel modes) configuration.  In addition, all traps into the
+  hypervisor must be disabled, and PL1 access must be granted for all
+  peripherals and CPU resources for which this is architecturally
+  possible.  Except for entering in HYP mode, the system configuration
+  should be such that a kernel which does not include support for the
+  virtualization extensions can boot correctly without extra help.
+
 - The boot loader is expected to call the kernel image by jumping
   directly to the first instruction of the kernel image.