Revert workaround for Neoverse N1 erratum 1800710 ...

This reverts commit 11af40b, reversing
changes made to 2afcf1d.

This errata workaround did not work as intended so we are reverting this
change.  In the future, when the corrected workaround is published in an
SDEN, we will push a new workaround.

This is the patch being reverted:
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4750

Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: I20aa064c1bac9671939e657bec269d32b9e75a97

Workaround for Neoverse N1 erratum 1800710 ...

Neoverse N1 erratum 1800710 is a Cat B erratum, present in older
revisions of the Neoverse N1 processor core.  The workaround is to
set a bit in the ECTLR_EL1 system register, which disables allocation
of splintered pages in the L2 TLB.

This errata is explained in this SDEN:
https://static.docs.arm.com/sden885747/f/Arm_Neoverse_N1_MP050_Software_Developer_Errata_Notice_v21.pdf

Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: Ie5b15c8bc3235e474a06a57c3ec70684361857a6

Workaround for Cortex A77 erratum 1800714 ...

Cortex A77 erratum 1800714 is a Cat B erratum, present in older
revisions of the Cortex A77 processor core.  The workaround is to
set a bit in the ECTLR_EL1 system register, which disables allocation
of splintered pages in the L2 TLB.

Since this is the first errata workaround implemented for Cortex A77,
this patch also adds the required cortex_a77_reset_func in the file
lib/cpus/aarch64/cortex_a77.S.

This errata is explained in this SDEN:
https://static.docs.arm.com/101992/0010/Arm_Cortex_A77_MP074_Software_Developer_Errata_Notice_v10.pdf

Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: I844de34ee1bd0268f80794e2d9542de2f30fd3ad

Workaround for Cortex A76 erratum 1800710 ...

Cortex A76 erratum 1800710 is a Cat B erratum, present in older
revisions of the Cortex A76 processor core.  The workaround is to
set a bit in the ECTLR_EL1 system register, which disables allocation
of splintered pages in the L2 TLB.

This errata is explained in this SDEN:
https://static.docs.arm.com/sden885749/g/Arm_Cortex_A76_MP052_Software_Developer_Errata_Notice_v20.pdf

Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: Ifc34f2e9e053dcee6a108cfb7df7ff7f497c9493

Workaround for Cortex A76 erratum 1791580 ...

Cortex A76 erratum 1791580 is a Cat B erratum present in earlier
revisions of the Cortex A76. The workaround is to set a bit in the
implementation defined CPUACTLR2 register, which forces atomic store
operations to write-back memory to be performed in the L1 data cache.

This errata is explained in this SDEN:
https://static.docs.arm.com/sden885749/g/Arm_Cortex_A76_MP052_Software_Developer_Errata_Notice_v20.pdf

Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: Iefd58159b3f2e2286138993317b98e57dc361925

Rename Cortex-Hercules to Cortex-A78 ...

Change-Id: I89b90cbdfc8f2aa898b4f3676a4764f060f8e138
Signed-off-by: Jimmy Brisson <jimmy.brisson@arm.com>

cpus: higher performance non-cacheable load forwarding ...

The CPUACTLR_EL1 register on Cortex-A57 CPUs supports a bit to enable
non-cacheable streaming enhancement. Platforms can set this bit only
if their memory system meets the requirement that cache line fill
requests from the Cortex-A57 processor are atomic.

This patch adds support to enable higher performance non-cacheable load
forwarding for such platforms. Platforms must enable this support by
setting the 'A57_ENABLE_NONCACHEABLE_LOAD_FWD' flag from their
makefiles. This flag is disabled by default.

Change-Id: Ib27e55dd68d11a50962c0bbc5b89072208b4bac5
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

Neovers N1: added support to update presence of External LLC ...

CPUECTLR_EL1.EXTLLC bit indicates the presense of internal or external
last level cache(LLC) in the system, the reset value is internal LLC.

To cater for the platforms(like N1SDP) which has external LLC present
introduce a new build option 'NEOVERSE_N1_EXTERNAL_LLC' which can be
enabled by platform port.

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Ibf475fcd6fd44401897a71600f4eafe989921363

Workaround for Hercules erratum 1688305 ...

Erratum 1688305 is a Cat B erratum present in r0p0, r0p1 versions
of Hercules core. The erratum can be avoided by setting bit 1 of the
implementation defined register CPUACTLR2_EL1 to 1 to prevent store-
release from being dispatched before it is the oldest.

Change-Id: I2ac04f5d9423868b6cdd4ceb3d0ffa46e570efed
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

doc: Convert internal links to RST format ...

Currently links between documents are using the format:

<path/to/><filename>.rst

This was required for services like GitHub because they render each
document in isolation - linking to another document is like linking
to any other file, just provide the full path.

However, with the new approach, the .rst files are only the raw
source for the documents. Once the documents have been rendered
the output is now in another format (HTML in our case) and so,
when linking to another document, the link must point to the
rendered version and not the .rst file.

The RST spec provides a few methods for linking between content.
The parent of this patch enabled the automatic creation of anchors
for document titles - we will use these anchors as the targets for
our links. Additional anchors can be added by hand if needed, on
section and sub-section titles, for example.

An example of this new format, for a document with the title
"Firmware Design" is :ref:`Firmware Design`.

One big advantage of this is that anchors are not dependent on
paths. We can then move documents around, even between directories,
without breaking any links between documents. Links will need to be
updated only if the title of a document changes.

Change-Id: I9e2340a61dd424cbd8fd1ecc2dc166f460d81703
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

Neoverse N1 Errata Workaround 1542419 ...

Coherent I-cache is causing a prefetch violation where when the core
executes an instruction that has recently been modified, the core might
fetch a stale instruction which violates the ordering of instruction
fetches.

The workaround includes an instruction sequence to implementation
defined registers to trap all EL0 IC IVAU instructions to EL3 and a trap
handler to execute a TLB inner-shareable invalidation to an arbitrary
address followed by a DSB.

Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>
Change-Id: Ic3b7cbb11cf2eaf9005523ef5578a372593ae4d6

Workaround for Neoverse N1 erratum 1275112 ...

Neoverse N1 erratum 1275112 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set a bit in the implementation defined
CPUACTLR_EL1 system register, which delays instruction fetch after
branch misprediction.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html

Change-Id: If7fe55fe92e656fa6aea12327ab297f2e6119833
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>

Workaround for Neoverse N1 erratum 1262888 ...

Neoverse N1 erratum 1262888 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set a bit in the implementation defined
CPUECTLR_EL1 system register, which disables the MMU hardware prefetcher.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html

Change-Id: Ib733d748e32a7ea6a2783f3d5a9c5e13eee01105
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>

Workaround for Neoverse N1 erratum 1262606 ...

Neoverse N1 erratum 1262606 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set a bit in the implementation defined
CPUACTLR_EL1 system register, which delays instruction fetch after
branch misprediction.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html

Change-Id: Idd980e9d5310232d38f0ce272862e1fb0f02ce9a
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>

Workaround for Neoverse N1 erratum 1257314 ...

Neoverse N1 erratum 1257314 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set a bit in the implementation defined
CPUACTLR3_EL1 system register, which prevents parallel
execution of divide and square root instructions.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html

Change-Id: I54f0f40ff9043efee40d51e796b92ed85b394cbb
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>

Workaround for Neoverse N1 erratum 1220197 ...

Neoverse N1 erratum 1220197 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set two bits in the implementation defined
CPUECTLR_EL1 system register, which disables write streaming to the L2.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html

Change-Id: I9c3373f1b6d67d21ee71b2b80aec5e96826818e8
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>

Workaround for Neoverse N1 erratum 1207823 ...

Neoverse N1 erratum 1207823 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set a bit in the implementation defined
CPUACTLR2_EL1 system register.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html

Change-Id: Ia932337821f1ef0d644db3612480462a8d924d21
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>

Workaround for Neoverse N1 erratum 1165347 ...

Neoverse N1 erratum 1165347 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set two bits in the implementation defined
CPUACTLR2_EL1 system register.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html

Change-Id: I163d0ea00578245c1323d2340314cdc3088c450d
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>

Workaround for Neoverse N1 erratum 1130799 ...

Neoverse N1 erratum 1130799 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set a bit in the implementation defined
CPUACTLR2_EL1 system register.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html

Change-Id: I252bc45f9733443ba0503fefe62f50fdea61da6d
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>

Workaround for Neoverse N1 erratum 1073348 ...

Neoverse N1 erratum 1073348 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set a bit in the implementation defined
CPUACTLR_EL1 system register, which disables static prediction.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html

Change-Id: I674126c0af6e068eecb379a190bcf7c75dcbca8e
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>

Neoverse N1: Introduce workaround for Neoverse N1 erratum 1315703 ...

Neoverse N1 erratum 1315703 is a Cat A (rare) erratum [1], present in
older revisions of the Neoverse N1 processor core.
The workaround is to set a bit in the implementation defined CPUACTLR2_EL1
system register, which will disable the load-bypass-store feature.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdocpjdoc-466751330-1032/index.html

Change-Id: I5c708dbe0efa4daa0bcb6bd9622c5efe19c03af9
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Cortex-A55: workarounds for errata 1221012 ...

The workaround is added to the Cortex-A55 cpu specific file. The
workaround is disabled by default and have to be explicitly enabled by
the platform integrator.

Change-Id: I3e6fd10df6444122a8ee7d08058946ff1cc912f8
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>

doc: Remove per-page contents lists ...

These are no longer needed as there will always be a table of contents
rendered to the left of every page.

Some of these lists can be quite long and, when opening a page, the
reader sees nothing but a huge list of contents! After this patch,
the document contents are front-and-centre and the contents are
nicely rendered in the sidebar without duplication.

Change-Id: I444754d548ec91d00f2b04e861de8dde8856aa62
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

doc: Move documents into subdirectories ...

This change creates the following directories under docs/
in order to provide a grouping for the content:

- components
- design
- getting_started
- perf
- process

In each of these directories an index.rst file is created
and this serves as an index / landing page for each of the
groups when the pages are compiled. Proper layout of the
top-level table of contents relies on this directory/index
structure.

Without this patch it is possible to build the documents
correctly with Sphinx but the output looks messy because
there is no overall hierarchy.

Change-Id: I3c9f4443ec98571a56a6edf775f2c8d74d7f429f
Signed-off-by: Paul Beesley <paul.beesley@arm.com>