The EAC1 release of the SME specification adds the FA64 feature which
requires enablement at higher ELs before lower ELs can use it. Document
what we require from higher ELs in our boot requirements.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211026111802.12853-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
It is amazing that we never documented this absolutely basic
requirement: if you boot the kernel at EL2, you'd better
enable the HVC instruction from EL3.
Really, just do it.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210812190213.2601506-6-maz@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Document our requirements for initialisation of the Scalable Matrix
Extension (SME) at kernel start. While we do have the ability to handle
mismatched vector lengths we will reject any late CPUs that can't support
the minimum set we determine at boot so for clarity we document a
requirement that all CPUs make the same vector length available.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210720204220.22951-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
v8.7 of the architecture introduced FEAT_HCX which adds an additional
hypervisor configuration register HCRX_EL2. Even though Linux does not
currently make use of this feature let's document that the EL3 trap for
access to the register should be disabled so that we are able to make
use of it in future.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210512162350.20349-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
We do not currently document the requirements for configuration of the
SVE system registers when booting the kernel, let's do so for completeness.
We don't have a hard requirement that the vector lengths configured on
different CPUs on initial boot be consistent since we have logic to
constrain to the minimum supported value but we will reject any late CPUs
which can't support the current maximum and introducing the concept of
late CPUs seemed more complex than was useful so we require that all CPUs
use the same value.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210412151955.16078-4-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
We do not explicitly require that systems with FPSIMD support and EL3 have
disabled EL3 traps when the kernel is started, while it is unlikely that
systems will get this wrong for the sake of completeness let's spell it
out.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210412151955.16078-3-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently we require that a number of system registers be configured to
disable traps when starting the kernel. Add an explicit note that the
requirement is that the system behave as if the traps are disabled so
transparent handling of the traps is fine, this should be implicit for
people familiar with working with standards documents but it doesn't hurt
to be explicit.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210412151955.16078-2-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Currently we require that software at a higher exception level initialise
all registers at the exception level the kernel will be entered prior to
starting the kernel in order to ensure that there is nothing uninitialised
which could result in an UNKNOWN state while running the kernel. The
expectation is that the software running at the highest exception levels
will be tightly coupled to the system and can ensure that all available
features are appropriately initialised and that the kernel can initialise
anything else.
There is a gap here in the case where new registers are added to lower
exception levels that require initialisation but the kernel does not yet
understand them. Extend the requirement to also include exception levels
below the one where the kernel is entered to cover this.
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210401180942.35815-4-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The arm64 FEAT_FGT extension introduces a set of traps to EL2 for accesses
to small sets of registers and instructions from EL1 and EL0, access to
which is controlled by EL3. Require access to it so that it is
available to us in future and so that we can ensure these traps are
disabled during boot.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210401180942.35815-2-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
set from Mauro toward the completion of the RST conversion. I *really*
hope we are getting close to the end of this. Meanwhile, those patches
reach pretty far afield to update document references around the tree;
there should be no actual code changes there. There will be, alas, more of
the usual trivial merge conflicts.
Beyond that we have more translations, improvements to the sphinx
scripting, a number of additions to the sysctl documentation, and lots of
fixes.
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Merge tag 'docs-5.8' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A fair amount of stuff this time around, dominated by yet another
massive set from Mauro toward the completion of the RST conversion. I
*really* hope we are getting close to the end of this. Meanwhile,
those patches reach pretty far afield to update document references
around the tree; there should be no actual code changes there. There
will be, alas, more of the usual trivial merge conflicts.
Beyond that we have more translations, improvements to the sphinx
scripting, a number of additions to the sysctl documentation, and lots
of fixes"
* tag 'docs-5.8' of git://git.lwn.net/linux: (130 commits)
Documentation: fixes to the maintainer-entry-profile template
zswap: docs/vm: Fix typo accept_threshold_percent in zswap.rst
tracing: Fix events.rst section numbering
docs: acpi: fix old http link and improve document format
docs: filesystems: add info about efivars content
Documentation: LSM: Correct the basic LSM description
mailmap: change email for Ricardo Ribalda
docs: sysctl/kernel: document unaligned controls
Documentation: admin-guide: update bug-hunting.rst
docs: sysctl/kernel: document ngroups_max
nvdimm: fixes to maintainter-entry-profile
Documentation/features: Correct RISC-V kprobes support entry
Documentation/features: Refresh the arch support status files
Revert "docs: sysctl/kernel: document ngroups_max"
docs: move locking-specific documents to locking/
docs: move digsig docs to the security book
docs: move the kref doc into the core-api book
docs: add IRQ documentation at the core-api book
docs: debugging-via-ohci1394.txt: add it to the core-api book
docs: fix references for ipmi.rst file
...
Although we require that the loaded kernel Image has been cleaned to the
PoC, we neglect to spell out the state of the I-cache. Although this
should be reasonably obvious, it doesn't hurt to be explicit.
Require that the I-cache doesn't hold any stale entries for the kernel
Image at boot.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200423093658.10602-1-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Get rid of those warnings:
Documentation/arm64/booting.rst:253: WARNING: Unexpected indentation.
Documentation/arm64/booting.rst:259: WARNING: Block quote ends without a blank line; unexpected unindent.
By adding an extra blank lines where needed.
While here, use list markups on some places, as otherwise Sphinx
will consider the next lines as continuation of the privious ones.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/121b267be0a102fde73498c31792e5a9309013cc.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The activity monitors extension is an optional extension introduced
by the ARMv8.4 CPU architecture.
Add initial documentation for the AMUv1 extension:
- arm64/amu.txt: AMUv1 documentation
- arm64/booting.txt: system registers initialisation
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
It goes without saying, but better saying it: the kernel expects
ICC_CTLR_EL3.PMHE to have the same value across all CPUs, and
for that setting not to change during the lifetime of the kernel.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
- DT binding schema examples are now validated against the schemas.
Various examples are fixed due to that.
- Sync dtc with upstream version v1.5.0-30-g702c1b6c0e73
- Initial schemas for networking bindings. This includes ethernet, phy
and mdio common bindings with several Allwinner and stmmac converted
to the schema.
- Conversion of more Arm top-level SoC/board bindings to DT schema
- Conversion of PSCI binding to DT schema
- Rework Arm CPU schema to coexist with other CPU schemas
- Add a bunch of missing vendor prefixes and new ones for SoChip,
Sipeed, Kontron, B&R Industrial Automation GmbH, and Espressif
- Add Mediatek UART RX wakeup support to binding
- Add reset to ST UART binding
- Remove some Linuxisms from the endianness common-properties.txt
binding
- Make the flattened DT read-only after init
- Ignore disabled reserved memory nodes
- Clean-up some dead code in FDT functions
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Merge tag 'devicetree-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull Devicetree updates from Rob Herring:
- DT binding schema examples are now validated against the schemas.
Various examples are fixed due to that.
- Sync dtc with upstream version v1.5.0-30-g702c1b6c0e73
- Initial schemas for networking bindings. This includes ethernet, phy
and mdio common bindings with several Allwinner and stmmac converted
to the schema.
- Conversion of more Arm top-level SoC/board bindings to DT schema
- Conversion of PSCI binding to DT schema
- Rework Arm CPU schema to coexist with other CPU schemas
- Add a bunch of missing vendor prefixes and new ones for SoChip,
Sipeed, Kontron, B&R Industrial Automation GmbH, and Espressif
- Add Mediatek UART RX wakeup support to binding
- Add reset to ST UART binding
- Remove some Linuxisms from the endianness common-properties.txt
binding
- Make the flattened DT read-only after init
- Ignore disabled reserved memory nodes
- Clean-up some dead code in FDT functions
* tag 'devicetree-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (56 commits)
dt-bindings: vendor-prefixes: add Sipeed
dt-bindings: vendor-prefixes: add SoChip
dt-bindings: 83xx-512x-pci: Drop cell-index property
dt-bindings: serial: add documentation for Rx in-band wakeup support
dt-bindings: arm: Convert RDA Micro board/soc bindings to json-schema
of: unittest: simplify getting the adapter of a client
of/fdt: pass early_init_dt_reserve_memory_arch() with bool type nomap
of/platform: Drop superfluous cast in of_device_make_bus_id()
dt-bindings: usb: ehci: Fix example warnings
dt-bindings: net: Use phy-mode instead of phy-connection-type
dt-bindings: simple-framebuffer: Add requirement for pipelines
dt-bindings: display: Fix simple-framebuffer example
dt-bindings: net: mdio: Add child nodes
dt-bindings: net: mdio: Add address and size cells
dt-bindings: net: mdio: Add a nodename pattern
dt-bindings: mtd: sunxi-nand: Drop 'maxItems' from child 'reg' property
dt-bindings: arm: Limit cpus schema to only check Arm 'cpu' nodes
dt-bindings: backlight: lm3630a: correct schema validation
dt-bindings: net: dwmac: Deprecate the PHY reset properties
dt-bindings: net: sun8i-emac: Convert the binding to a schemas
...
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>
