Workaround for CVE-2017-5715 on Cortex A57 and A72 ...

Invalidate the Branch Target Buffer (BTB) on entry to EL3 by disabling
and enabling the MMU.  To achieve this without performing any branch
instruction, a per-cpu vbar is installed which executes the workaround
and then branches off to the corresponding vector entry in the main
vector table.  A side effect of this change is that the main vbar is
configured before any reset handling.  This is to allow the per-cpu
reset function to override the vbar setting.

This workaround is enabled by default on the affected CPUs.

Change-Id: I97788d38463a5840a410e3cea85ed297a1678265
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

Cortex-A72: Implement workaround for erratum 859971 ...

Erratum 855971 applies to revision r0p3 or earlier Cortex-A72 CPUs. The
recommended workaround is to disable instruction prefetch.

Change-Id: I7fde74ee2a8a23b2a8a1891b260f0eb909fad4bf
Signed-off-by: Eleanor Bonnici <Eleanor.bonnici@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

Cortex-A57: Implement workaround for erratum 859972 ...

Erratum 855972 applies to revision r1p3 or earlier Cortex-A57 CPUs. The
recommended workaround is to disable instruction prefetch.

Change-Id: I56eeac0b753eb1432bd940083372ad6f7e93b16a
Signed-off-by: Eleanor Bonnici <Eleanor.bonnici@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

Add doc for some Cortex A53 errata workarounds ...

Add documentation for errata 835769 and 843419 workarounds introduced in
commit a94cc37

Fixes ARM-software/tf-issues#504

Change-Id: I7f3db53dfc5f3827b32663f483d3302bc9679b19
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

Convert documentation to reStructuredText ...

Due to recent issues in the rendering of the documentation on GitHub and
some long-standing issues like the lack of automatic table of content in
Markdown, the documentation has been converted to reStructuredText.
Basic constructs looks pretty similar to Markdown.

Automatically convert GitHub markdown documentation to reStructuredText
using pandoc.

Change-Id: If20b695acedc6d1b49c8d9fb64efd6b6ba23f4a9
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>