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

Pull ARM64 updates from Catalin Marinas:
 - KGDB support for arm64
 - PCI I/O space extended to 16M (in preparation of PCIe support
   patches)
 - Dropping ZONE_DMA32 in favour of ZONE_DMA (we only need one for the
   time being), together with swiotlb late initialisation to correctly
   setup the bounce buffer
 - DMA API cache maintenance support (not all ARMv8 platforms have
   hardware cache coherency)
 - Crypto extensions advertising via ELF_HWCAP2 for compat user space
 - Perf support for dwarf unwinding in compat mode
 - asm/tlb.h converted to the generic mmu_gather code
 - asm-generic rwsem implementation
 - Code clean-up

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (42 commits)
  arm64: Remove pgprot_dmacoherent()
  arm64: Support DMA_ATTR_WRITE_COMBINE
  arm64: Implement custom mmap functions for dma mapping
  arm64: Fix __range_ok macro
  arm64: Fix duplicated Kconfig entries
  arm64: mm: Route pmd thp functions through pte equivalents
  arm64: rwsem: use asm-generic rwsem implementation
  asm-generic: rwsem: de-PPCify rwsem.h
  arm64: enable generic CPU feature modalias matching for this architecture
  arm64: smp: make local symbol static
  arm64: debug: make local symbols static
  ARM64: perf: support dwarf unwinding in compat mode
  ARM64: perf: add support for frame pointer unwinding in compat mode
  ARM64: perf: add support for perf registers API
  arm64: Add boot time configuration of Intermediate Physical Address size
  arm64: Do not synchronise I and D caches for special ptes
  arm64: Make DMA coherent and strongly ordered mappings not executable
  arm64: barriers: add dmb barrier
  arm64: topology: Implement basic CPU topology support
  arm64: advertise ARMv8 extensions to 32-bit compat ELF binaries
  ...

1 files changed, 29 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
new file mode 100644
index 000000000000..cd4ac0516488
--- /dev/null
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_CPUFEATURE_H
+#define __ASM_CPUFEATURE_H
+
+#include <asm/hwcap.h>
+
+/*
+ * In the arm64 world (as in the ARM world), elf_hwcap is used both internally
+ * in the kernel and for user space to keep track of which optional features
+ * are supported by the current system. So let's map feature 'x' to HWCAP_x.
+ * Note that HWCAP_x constants are bit fields so we need to take the log.
+ */
+
+#define MAX_CPU_FEATURES	(8 * sizeof(elf_hwcap))
+#define cpu_feature(x)		ilog2(HWCAP_ ## x)
+
+static inline bool cpu_have_feature(unsigned int num)
+{
+	return elf_hwcap & (1UL << num);
+}
+
+#endif