Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "Once again, Catalin's off on holiday and I'm looking after the arm64
  tree.  Please can you pull the following arm64 updates for 3.17?

  Note that this branch also includes the new GICv3 driver (merged via a
  stable tag from Jason's irqchip tree), since there is a fix for older
  binutils on top.

  Changes include:
   - context tracking support (NO_HZ_FULL) which narrowly missed 3.16
   - vDSO layout rework following Andy's work on x86
   - TEXT_OFFSET fuzzing for bootloader testing
   - /proc/cpuinfo tidy-up
   - preliminary work to support 48-bit virtual addresses, but this is
     currently disabled until KVM has been ported to use it (the patches
     do, however, bring some nice clean-up)
   - boot-time CPU sanity checks (especially useful on heterogenous
     systems)
   - support for syscall auditing
   - support for CC_STACKPROTECTOR
   - defconfig updates"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (55 commits)
  arm64: add newline to I-cache policy string
  Revert "arm64: dmi: Add SMBIOS/DMI support"
  arm64: fpsimd: fix a typo in fpsimd_save_partial_state ENDPROC
  arm64: don't call break hooks for BRK exceptions from EL0
  arm64: defconfig: enable devtmpfs mount option
  arm64: vdso: fix build error when switching from LE to BE
  arm64: defconfig: add virtio support for running as a kvm guest
  arm64: gicv3: Allow GICv3 compilation with older binutils
  arm64: fix soft lockup due to large tlb flush range
  arm64/crypto: fix makefile rule for aes-glue-%.o
  arm64: Do not invoke audit_syscall_* functions if !CONFIG_AUDIT_SYSCALL
  arm64: Fix barriers used for page table modifications
  arm64: Add support for 48-bit VA space with 64KB page configuration
  arm64: asm/pgtable.h pmd/pud definitions clean-up
  arm64: Determine the vmalloc/vmemmap space at build time based on VA_BITS
  arm64: Clean up the initial page table creation in head.S
  arm64: Remove asm/pgtable-*level-types.h files
  arm64: Remove asm/pgtable-*level-hwdef.h files
  arm64: Convert bool ARM64_x_LEVELS to int ARM64_PGTABLE_LEVELS
  arm64: mm: Implement 4 levels of translation tables
  ...

1 files changed, 35 insertions, 8 deletions

diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt
index 37fc4f632176..85af34d55cee 100644
--- a/Documentation/arm64/booting.txt
+++ b/Documentation/arm64/booting.txt
@@ -72,27 +72,54 @@ The decompressed kernel image contains a 64-byte header as follows:
 
   u32 code0;			/* Executable code */
   u32 code1;			/* Executable code */
-  u64 text_offset;		/* Image load offset */
-  u64 res0	= 0;		/* reserved */
-  u64 res1	= 0;		/* reserved */
+  u64 text_offset;		/* Image load offset, little endian */
+  u64 image_size;		/* Effective Image size, little endian */
+  u64 flags;			/* kernel flags, little endian */
   u64 res2	= 0;		/* reserved */
   u64 res3	= 0;		/* reserved */
   u64 res4	= 0;		/* reserved */
   u32 magic	= 0x644d5241;	/* Magic number, little endian, "ARM\x64" */
-  u32 res5 = 0;      		/* reserved */
+  u32 res5;      		/* reserved (used for PE COFF offset) */
 
 
 Header notes:
 
+- As of v3.17, all fields are little endian unless stated otherwise.
+
 - code0/code1 are responsible for branching to stext.
+
 - when booting through EFI, code0/code1 are initially skipped.
   res5 is an offset to the PE header and the PE header has the EFI
-  entry point (efi_stub_entry). When the stub has done its work, it
+  entry point (efi_stub_entry).  When the stub has done its work, it
   jumps to code0 to resume the normal boot process.
 
-The image must be placed at the specified offset (currently 0x80000)
-from the start of the system RAM and called there. The start of the
-system RAM must be aligned to 2MB.
+- Prior to v3.17, the endianness of text_offset was not specified.  In
+  these cases image_size is zero and text_offset is 0x80000 in the
+  endianness of the kernel.  Where image_size is non-zero image_size is
+  little-endian and must be respected.  Where image_size is zero,
+  text_offset can be assumed to be 0x80000.
+
+- The flags field (introduced in v3.17) is a little-endian 64-bit field
+  composed as follows:
+  Bit 0: 	Kernel endianness.  1 if BE, 0 if LE.
+  Bits 1-63:	Reserved.
+
+- When image_size is zero, a bootloader should attempt to keep as much
+  memory as possible free for use by the kernel immediately after the
+  end of the kernel image. The amount of space required will vary
+  depending on selected features, and is effectively unbound.
+
+The Image must be placed text_offset bytes from a 2MB aligned base
+address near the start of usable system RAM and called there. Memory
+below that base address is currently unusable by Linux, and therefore it
+is strongly recommended that this location is the start of system RAM.
+At least image_size bytes from the start of the image must be free for
+use by the kernel.
+
+Any memory described to the kernel (even that below the 2MB aligned base
+address) which is not marked as reserved from the kernel e.g. with a
+memreserve region in the device tree) will be considered as available to
+the kernel.
 
 Before jumping into the kernel, the following conditions must be met: