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

…el/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "The big highlight is support for the Scalable Vector Extension (SVE)
  which required extensive ABI work to ensure we don't break existing
  applications by blowing away their signal stack with the rather large
  new vector context (<= 2 kbit per vector register). There's further
  work to be done optimising things like exception return, but the ABI
  is solid now.

  Much of the line count comes from some new PMU drivers we have, but
  they're pretty self-contained and I suspect we'll have more of them in
  future.

  Plenty of acronym soup here:

   - initial support for the Scalable Vector Extension (SVE)

   - improved handling for SError interrupts (required to handle RAS
     events)

   - enable GCC support for 128-bit integer types

   - remove kernel text addresses from backtraces and register dumps

   - use of WFE to implement long delay()s

   - ACPI IORT updates from Lorenzo Pieralisi

   - perf PMU driver for the Statistical Profiling Extension (SPE)

   - perf PMU driver for Hisilicon's system PMUs

   - misc cleanups and non-critical fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (97 commits)
  arm64: Make ARMV8_DEPRECATED depend on SYSCTL
  arm64: Implement __lshrti3 library function
  arm64: support __int128 on gcc 5+
  arm64/sve: Add documentation
  arm64/sve: Detect SVE and activate runtime support
  arm64/sve: KVM: Hide SVE from CPU features exposed to guests
  arm64/sve: KVM: Treat guest SVE use as undefined instruction execution
  arm64/sve: KVM: Prevent guests from using SVE
  arm64/sve: Add sysctl to set the default vector length for new processes
  arm64/sve: Add prctl controls for userspace vector length management
  arm64/sve: ptrace and ELF coredump support
  arm64/sve: Preserve SVE registers around EFI runtime service calls
  arm64/sve: Preserve SVE registers around kernel-mode NEON use
  arm64/sve: Probe SVE capabilities and usable vector lengths
  arm64: cpufeature: Move sys_caps_initialised declarations
  arm64/sve: Backend logic for setting the vector length
  arm64/sve: Signal handling support
  arm64/sve: Support vector length resetting for new processes
  arm64/sve: Core task context handling
  arm64/sve: Low-level CPU setup
  ...

Documentation/arm64/cpu-feature-registers.txt

@@ -110,10 +110,20 @@ infrastructure:
      x--------------------------------------------------x
      | Name                         |  bits   | visible |
      |--------------------------------------------------|
-     | RES0                         | [63-32] |    n    |
+     | RES0                         | [63-48] |    n    |
+     |--------------------------------------------------|
+     | DP                           | [47-44] |    y    |
+     |--------------------------------------------------|
+     | SM4                          | [43-40] |    y    |
+     |--------------------------------------------------|
+     | SM3                          | [39-36] |    y    |
+     |--------------------------------------------------|
+     | SHA3                         | [35-32] |    y    |
      |--------------------------------------------------|
      | RDM                          | [31-28] |    y    |
      |--------------------------------------------------|
+     | RES0                         | [27-24] |    n    |
+     |--------------------------------------------------|
      | ATOMICS                      | [23-20] |    y    |
      |--------------------------------------------------|
      | CRC32                        | [19-16] |    y    |
@@ -132,7 +142,11 @@ infrastructure:
      x--------------------------------------------------x
      | Name                         |  bits   | visible |
      |--------------------------------------------------|
-     | RES0                         | [63-28] |    n    |
+     | RES0                         | [63-36] |    n    |
+     |--------------------------------------------------|
+     | SVE                          | [35-32] |    y    |
+     |--------------------------------------------------|
+     | RES0                         | [31-28] |    n    |
      |--------------------------------------------------|
      | GIC                          | [27-24] |    n    |
      |--------------------------------------------------|

Documentation/arm64/elf_hwcaps.txt

@@ -0,0 +1,160 @@
+ARM64 ELF hwcaps
+================
+
+This document describes the usage and semantics of the arm64 ELF hwcaps.
+
+
+1. Introduction
+---------------
+
+Some hardware or software features are only available on some CPU
+implementations, and/or with certain kernel configurations, but have no
+architected discovery mechanism available to userspace code at EL0. The
+kernel exposes the presence of these features to userspace through a set
+of flags called hwcaps, exposed in the auxilliary vector.
+
+Userspace software can test for features by acquiring the AT_HWCAP entry
+of the auxilliary vector, and testing whether the relevant flags are
+set, e.g.
+
+bool floating_point_is_present(void)
+{
+	unsigned long hwcaps = getauxval(AT_HWCAP);
+	if (hwcaps & HWCAP_FP)
+		return true;
+
+	return false;
+}
+
+Where software relies on a feature described by a hwcap, it should check
+the relevant hwcap flag to verify that the feature is present before
+attempting to make use of the feature.
+
+Features cannot be probed reliably through other means. When a feature
+is not available, attempting to use it may result in unpredictable
+behaviour, and is not guaranteed to result in any reliable indication
+that the feature is unavailable, such as a SIGILL.
+
+
+2. Interpretation of hwcaps
+---------------------------
+
+The majority of hwcaps are intended to indicate the presence of features
+which are described by architected ID registers inaccessible to
+userspace code at EL0. These hwcaps are defined in terms of ID register
+fields, and should be interpreted with reference to the definition of
+these fields in the ARM Architecture Reference Manual (ARM ARM).
+
+Such hwcaps are described below in the form:
+
+    Functionality implied by idreg.field == val.
+
+Such hwcaps indicate the availability of functionality that the ARM ARM
+defines as being present when idreg.field has value val, but do not
+indicate that idreg.field is precisely equal to val, nor do they
+indicate the absence of functionality implied by other values of
+idreg.field.
+
+Other hwcaps may indicate the presence of features which cannot be
+described by ID registers alone. These may be described without
+reference to ID registers, and may refer to other documentation.
+
+
+3. The hwcaps exposed in AT_HWCAP
+---------------------------------
+
+HWCAP_FP
+
+    Functionality implied by ID_AA64PFR0_EL1.FP == 0b0000.
+
+HWCAP_ASIMD
+
+    Functionality implied by ID_AA64PFR0_EL1.AdvSIMD == 0b0000.
+
+HWCAP_EVTSTRM
+
+    The generic timer is configured to generate events at a frequency of
+    approximately 100KHz.
+
+HWCAP_AES
+
+    Functionality implied by ID_AA64ISAR1_EL1.AES == 0b0001.
+
+HWCAP_PMULL
+
+    Functionality implied by ID_AA64ISAR1_EL1.AES == 0b0010.
+
+HWCAP_SHA1
+
+    Functionality implied by ID_AA64ISAR0_EL1.SHA1 == 0b0001.
+
+HWCAP_SHA2
+
+    Functionality implied by ID_AA64ISAR0_EL1.SHA2 == 0b0001.
+
+HWCAP_CRC32
+
+    Functionality implied by ID_AA64ISAR0_EL1.CRC32 == 0b0001.
+
+HWCAP_ATOMICS
+
+    Functionality implied by ID_AA64ISAR0_EL1.Atomic == 0b0010.
+
+HWCAP_FPHP
+
+    Functionality implied by ID_AA64PFR0_EL1.FP == 0b0001.
+
+HWCAP_ASIMDHP
+
+    Functionality implied by ID_AA64PFR0_EL1.AdvSIMD == 0b0001.
+
+HWCAP_CPUID
+
+    EL0 access to certain ID registers is available, to the extent
+    described by Documentation/arm64/cpu-feature-registers.txt.
+
+    These ID registers may imply the availability of features.
+
+HWCAP_ASIMDRDM
+
+    Functionality implied by ID_AA64ISAR0_EL1.RDM == 0b0001.
+
+HWCAP_JSCVT
+
+    Functionality implied by ID_AA64ISAR1_EL1.JSCVT == 0b0001.
+
+HWCAP_FCMA
+
+    Functionality implied by ID_AA64ISAR1_EL1.FCMA == 0b0001.
+
+HWCAP_LRCPC
+
+    Functionality implied by ID_AA64ISAR1_EL1.LRCPC == 0b0001.
+
+HWCAP_DCPOP
+
+    Functionality implied by ID_AA64ISAR1_EL1.DPB == 0b0001.
+
+HWCAP_SHA3
+
+    Functionality implied by ID_AA64ISAR0_EL1.SHA3 == 0b0001.
+
+HWCAP_SM3
+
+    Functionality implied by ID_AA64ISAR0_EL1.SM3 == 0b0001.
+
+HWCAP_SM4
+
+    Functionality implied by ID_AA64ISAR0_EL1.SM4 == 0b0001.
+
+HWCAP_ASIMDDP
+
+    Functionality implied by ID_AA64ISAR0_EL1.DP == 0b0001.
+
+HWCAP_SHA512
+
+    Functionality implied by ID_AA64ISAR0_EL1.SHA2 == 0b0002.
+
+HWCAP_SVE
+
+    Functionality implied by ID_AA64PFR0_EL1.SVE == 0b0001.

Documentation/arm64/memory.txt

@@ -86,9 +86,9 @@ Translation table lookup with 64KB pages:
  +-------------------------------------------------> [63] TTBR0/1
 
 
-When using KVM, the hypervisor maps kernel pages in EL2, at a fixed
-offset from the kernel VA (top 24bits of the kernel VA set to zero):
+When using KVM without the Virtualization Host Extensions, the hypervisor
+maps kernel pages in EL2 at a fixed offset from the kernel VA. See the
+kern_hyp_va macro for more details.
 
-Start			End			Size		Use
------------------------------------------------------------------------
-0000004000000000	0000007fffffffff	 256GB		kernel objects mapped in HYP
+When using KVM with the Virtualization Host Extensions, no additional
+mappings are created, since the host kernel runs directly in EL2.