Merge tag 'arm64-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64

Pull arm64 support from Catalin Marinas:
 "Linux support for the 64-bit ARM architecture (AArch64)

  Features currently supported:
   - 39-bit address space for user and kernel (each)
   - 4KB and 64KB page configurations
   - Compat (32-bit) user applications (ARMv7, EABI only)
   - Flattened Device Tree (mandated for all AArch64 platforms)
   - ARM generic timers"

* tag 'arm64-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64: (35 commits)
  arm64: ptrace: remove obsolete ptrace request numbers from user headers
  arm64: Do not set the SMP/nAMP processor bit
  arm64: MAINTAINERS update
  arm64: Build infrastructure
  arm64: Miscellaneous header files
  arm64: Generic timers support
  arm64: Loadable modules
  arm64: Miscellaneous library functions
  arm64: Performance counters support
  arm64: Add support for /proc/sys/debug/exception-trace
  arm64: Debugging support
  arm64: Floating point and SIMD
  arm64: 32-bit (compat) applications support
  arm64: User access library functions
  arm64: Signal handling support
  arm64: VDSO support
  arm64: System calls handling
  arm64: ELF definitions
  arm64: SMP support
  arm64: DMA mapping API
  ...

2 files changed, 225 insertions, 0 deletions

diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt
new file mode 100644
index 000000000000..9c4d388daddc
--- /dev/null
+++ b/Documentation/arm64/booting.txt
@@ -0,0 +1,152 @@
+			Booting AArch64 Linux
+			=====================
+
+Author: Will Deacon <will.deacon@arm.com>
+Date  : 07 September 2012
+
+This document is based on the ARM booting document by Russell King and
+is relevant to all public releases of the AArch64 Linux kernel.
+
+The AArch64 exception model is made up of a number of exception levels
+(EL0 - EL3), with EL0 and EL1 having a secure and a non-secure
+counterpart.  EL2 is the hypervisor level and exists only in non-secure
+mode. EL3 is the highest priority level and exists only in secure mode.
+
+For the purposes of this document, we will use the term `boot loader'
+simply to define all software that executes on the CPU(s) before control
+is passed to the Linux kernel.  This may include secure monitor and
+hypervisor code, or it may just be a handful of instructions for
+preparing a minimal boot environment.
+
+Essentially, the boot loader should provide (as a minimum) the
+following:
+
+1. Setup and initialise the RAM
+2. Setup the device tree
+3. Decompress the kernel image
+4. Call the kernel image
+
+
+1. Setup and initialise RAM
+---------------------------
+
+Requirement: MANDATORY
+
+The boot loader is expected to find and initialise all RAM that the
+kernel will use for volatile data storage in the system.  It performs
+this in a machine dependent manner.  (It may use internal algorithms
+to automatically locate and size all RAM, or it may use knowledge of
+the RAM in the machine, or any other method the boot loader designer
+sees fit.)
+
+
+2. Setup the device tree
+-------------------------
+
+Requirement: MANDATORY
+
+The device tree blob (dtb) must be no bigger than 2 megabytes in size
+and placed at a 2-megabyte boundary within the first 512 megabytes from
+the start of the kernel image. This is to allow the kernel to map the
+blob using a single section mapping in the initial page tables.
+
+
+3. Decompress the kernel image
+------------------------------
+
+Requirement: OPTIONAL
+
+The AArch64 kernel does not currently provide a decompressor and
+therefore requires decompression (gzip etc.) to be performed by the boot
+loader if a compressed Image target (e.g. Image.gz) is used.  For
+bootloaders that do not implement this requirement, the uncompressed
+Image target is available instead.
+
+
+4. Call the kernel image
+------------------------
+
+Requirement: MANDATORY
+
+The decompressed kernel image contains a 32-byte header as follows:
+
+  u32 magic	= 0x14000008;	/* branch to stext, little-endian */
+  u32 res0	= 0;		/* reserved */
+  u64 text_offset;		/* Image load offset */
+  u64 res1	= 0;		/* reserved */
+  u64 res2	= 0;		/* reserved */
+
+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.
+
+Before jumping into the kernel, the following conditions must be met:
+
+- Quiesce all DMA capable devices so that memory does not get
+  corrupted by bogus network packets or disk data.  This will save
+  you many hours of debug.
+
+- Primary CPU general-purpose register settings
+  x0 = physical address of device tree blob (dtb) in system RAM.
+  x1 = 0 (reserved for future use)
+  x2 = 0 (reserved for future use)
+  x3 = 0 (reserved for future use)
+
+- CPU mode
+  All forms of interrupts must be masked in PSTATE.DAIF (Debug, SError,
+  IRQ and FIQ).
+  The CPU must be in either EL2 (RECOMMENDED in order to have access to
+  the virtualisation extensions) or non-secure EL1.
+
+- Caches, MMUs
+  The MMU must be off.
+  Instruction cache may be on or off.
+  Data cache must be off and invalidated.
+  External caches (if present) must be configured and disabled.
+
+- Architected timers
+  CNTFRQ must be programmed with the timer frequency.
+  If entering the kernel at EL1, CNTHCTL_EL2 must have EL1PCTEN (bit 0)
+  set where available.
+
+- Coherency
+  All CPUs to be booted by the kernel must be part of the same coherency
+  domain on entry to the kernel.  This may require IMPLEMENTATION DEFINED
+  initialisation to enable the receiving of maintenance operations on
+  each CPU.
+
+- System registers
+  All writable architected system registers at the exception level where
+  the kernel image will be entered must be initialised by software at a
+  higher exception level to prevent execution in an UNKNOWN state.
+
+The boot loader is expected to enter the kernel on each CPU in the
+following manner:
+
+- The primary CPU must jump directly to the first instruction of the
+  kernel image.  The device tree blob passed by this CPU must contain
+  for each CPU node:
+
+    1. An 'enable-method' property. Currently, the only supported value
+       for this field is the string "spin-table".
+
+    2. A 'cpu-release-addr' property identifying a 64-bit,
+       zero-initialised memory location.
+
+  It is expected that the bootloader will generate these device tree
+  properties and insert them into the blob prior to kernel entry.
+
+- Any secondary CPUs must spin outside of the kernel in a reserved area
+  of memory (communicated to the kernel by a /memreserve/ region in the
+  device tree) polling their cpu-release-addr location, which must be
+  contained in the reserved region.  A wfe instruction may be inserted
+  to reduce the overhead of the busy-loop and a sev will be issued by
+  the primary CPU.  When a read of the location pointed to by the
+  cpu-release-addr returns a non-zero value, the CPU must jump directly
+  to this value.
+
+- Secondary CPU general-purpose register settings
+  x0 = 0 (reserved for future use)
+  x1 = 0 (reserved for future use)
+  x2 = 0 (reserved for future use)
+  x3 = 0 (reserved for future use)
diff --git a/Documentation/arm64/memory.txt b/Documentation/arm64/memory.txt
new file mode 100644
index 000000000000..dbbdcbba75a3
--- /dev/null
+++ b/Documentation/arm64/memory.txt
@@ -0,0 +1,73 @@
+		     Memory Layout on AArch64 Linux
+		     ==============================
+
+Author: Catalin Marinas <catalin.marinas@arm.com>
+Date  : 20 February 2012
+
+This document describes the virtual memory layout used by the AArch64
+Linux kernel. The architecture allows up to 4 levels of translation
+tables with a 4KB page size and up to 3 levels with a 64KB page size.
+
+AArch64 Linux uses 3 levels of translation tables with the 4KB page
+configuration, allowing 39-bit (512GB) virtual addresses for both user
+and kernel. With 64KB pages, only 2 levels of translation tables are
+used but the memory layout is the same.
+
+User addresses have bits 63:39 set to 0 while the kernel addresses have
+the same bits set to 1. TTBRx selection is given by bit 63 of the
+virtual address. The swapper_pg_dir contains only kernel (global)
+mappings while the user pgd contains only user (non-global) mappings.
+The swapper_pgd_dir address is written to TTBR1 and never written to
+TTBR0.
+
+
+AArch64 Linux memory layout:
+
+Start			End			Size		Use
+-----------------------------------------------------------------------
+0000000000000000	0000007fffffffff	 512GB		user
+
+ffffff8000000000	ffffffbbfffcffff	~240GB		vmalloc
+
+ffffffbbfffd0000	ffffffbcfffdffff	  64KB		[guard page]
+
+ffffffbbfffe0000	ffffffbcfffeffff	  64KB		PCI I/O space
+
+ffffffbbffff0000	ffffffbcffffffff	  64KB		[guard page]
+
+ffffffbc00000000	ffffffbdffffffff	   8GB		vmemmap
+
+ffffffbe00000000	ffffffbffbffffff	  ~8GB		[guard, future vmmemap]
+
+ffffffbffc000000	ffffffbfffffffff	  64MB		modules
+
+ffffffc000000000	ffffffffffffffff	 256GB		memory
+
+
+Translation table lookup with 4KB pages:
+
++--------+--------+--------+--------+--------+--------+--------+--------+
+|63    56|55    48|47    40|39    32|31    24|23    16|15     8|7      0|
++--------+--------+--------+--------+--------+--------+--------+--------+
+ |                 |         |         |         |         |
+ |                 |         |         |         |         v
+ |                 |         |         |         |   [11:0]  in-page offset
+ |                 |         |         |         +-> [20:12] L3 index
+ |                 |         |         +-----------> [29:21] L2 index
+ |                 |         +---------------------> [38:30] L1 index
+ |                 +-------------------------------> [47:39] L0 index (not used)
+ +-------------------------------------------------> [63] TTBR0/1
+
+
+Translation table lookup with 64KB pages:
+
++--------+--------+--------+--------+--------+--------+--------+--------+
+|63    56|55    48|47    40|39    32|31    24|23    16|15     8|7      0|
++--------+--------+--------+--------+--------+--------+--------+--------+
+ |                 |    |               |              |
+ |                 |    |               |              v
+ |                 |    |               |            [15:0]  in-page offset
+ |                 |    |               +----------> [28:16] L3 index
+ |                 |    +--------------------------> [41:29] L2 index (only 38:29 used)
+ |                 +-------------------------------> [47:42] L1 index (not used)
+ +-------------------------------------------------> [63] TTBR0/1