docs: arm64: convert docs to ReST and rename to .rst

The documentation is in a format that is very close to ReST format.

The conversion is actually:
  - add blank lines in order to identify paragraphs;
  - fixing tables markups;
  - adding some lists markups;
  - marking literal blocks;
  - adjust some title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 0 insertions, 231 deletions

diff --git a/Documentation/arm64/elf_hwcaps.txt b/Documentation/arm64/elf_hwcaps.txt
deleted file mode 100644
index b73a2519ecf2..000000000000
--- a/Documentation/arm64/elf_hwcaps.txt
+++ /dev/null
@@ -1,231 +0,0 @@
-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 or
-AT_HWCAP2 entry of the auxiliary 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_AA64ISAR0_EL1.AES == 0b0001.
-
-HWCAP_PMULL
-
-    Functionality implied by ID_AA64ISAR0_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.
-
-HWCAP2_DCPODP
-
-    Functionality implied by ID_AA64ISAR1_EL1.DPB == 0b0010.
-
-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 == 0b0010.
-
-HWCAP_SVE
-
-    Functionality implied by ID_AA64PFR0_EL1.SVE == 0b0001.
-
-HWCAP2_SVE2
-
-    Functionality implied by ID_AA64ZFR0_EL1.SVEVer == 0b0001.
-
-HWCAP2_SVEAES
-
-    Functionality implied by ID_AA64ZFR0_EL1.AES == 0b0001.
-
-HWCAP2_SVEPMULL
-
-    Functionality implied by ID_AA64ZFR0_EL1.AES == 0b0010.
-
-HWCAP2_SVEBITPERM
-
-    Functionality implied by ID_AA64ZFR0_EL1.BitPerm == 0b0001.
-
-HWCAP2_SVESHA3
-
-    Functionality implied by ID_AA64ZFR0_EL1.SHA3 == 0b0001.
-
-HWCAP2_SVESM4
-
-    Functionality implied by ID_AA64ZFR0_EL1.SM4 == 0b0001.
-
-HWCAP_ASIMDFHM
-
-   Functionality implied by ID_AA64ISAR0_EL1.FHM == 0b0001.
-
-HWCAP_DIT
-
-    Functionality implied by ID_AA64PFR0_EL1.DIT == 0b0001.
-
-HWCAP_USCAT
-
-    Functionality implied by ID_AA64MMFR2_EL1.AT == 0b0001.
-
-HWCAP_ILRCPC
-
-    Functionality implied by ID_AA64ISAR1_EL1.LRCPC == 0b0010.
-
-HWCAP_FLAGM
-
-    Functionality implied by ID_AA64ISAR0_EL1.TS == 0b0001.
-
-HWCAP_SSBS
-
-    Functionality implied by ID_AA64PFR1_EL1.SSBS == 0b0010.
-
-HWCAP_PACA
-
-    Functionality implied by ID_AA64ISAR1_EL1.APA == 0b0001 or
-    ID_AA64ISAR1_EL1.API == 0b0001, as described by
-    Documentation/arm64/pointer-authentication.txt.
-
-HWCAP_PACG
-
-    Functionality implied by ID_AA64ISAR1_EL1.GPA == 0b0001 or
-    ID_AA64ISAR1_EL1.GPI == 0b0001, as described by
-    Documentation/arm64/pointer-authentication.txt.
-
-
-4. Unused AT_HWCAP bits
------------------------
-
-For interoperation with userspace, the kernel guarantees that bits 62
-and 63 of AT_HWCAP will always be returned as 0.