Commit Graph

10 Commits

Author SHA1 Message Date
Soby Mathew 683f788fa7 Fix the Cortex-A57 reset handler register usage
The CPU specific reset handlers no longer have the freedom
of using any general purpose register because it is being invoked
by the BL3-1 entry point in addition to BL1. The Cortex-A57 CPU
specific reset handler was overwriting x20 register which was being
used by the BL3-1 entry point to save the entry point information.
This patch fixes this bug by reworking the register allocation in the
Cortex-A57 reset handler to avoid using x20. The patch also
explicitly mentions the register clobber list for each of the
callee functions invoked by the reset handler

Change-Id: I28fcff8e742aeed883eaec8f6c4ee2bd3fce30df
2015-01-30 13:57:57 +00:00
Yatharth Kochar 79a97b2ef7 Call reset handlers upon BL3-1 entry.
This patch adds support to call the reset_handler() function in BL3-1 in the
cold and warm boot paths when another Boot ROM reset_handler() has already run.

This means the BL1 and BL3-1 versions of the CPU and platform specific reset
handlers may execute different code to each other. This enables a developer to
perform additional actions or undo actions already performed during the first
call of the reset handlers e.g. apply additional errata workarounds.

Typically, the reset handler will be first called from the BL1 Boot ROM. Any
additional functionality can be added to the reset handler when it is called
from BL3-1 resident in RW memory. The constant FIRST_RESET_HANDLER_CALL is used
to identify whether this is the first version of the reset handler code to be
executed or an overridden version of the code.

The Cortex-A57 errata workarounds are applied only if they have not already been
applied.

Fixes ARM-software/tf-issue#275

Change-Id: Id295f106e4fda23d6736debdade2ac7f2a9a9053
2015-01-26 19:04:15 +00:00
Soby Mathew 5541bb3f61 Optimize Cortex-A57 cluster power down sequence on Juno
This patch optimizes the Cortex-A57 cluster power down sequence by not
flushing the Level1 data cache. The L1 data cache and the L2 unified
cache are inclusive. A flush of the L2 by set/way flushes any dirty
lines from the L1 as well. This is a known safe deviation from the
Cortex-A57 TRM defined power down sequence. This optimization can be
enabled by the platform through the 'SKIP_A57_L1_FLUSH_PWR_DWN' build
flag. Each Cortex-A57 based platform must make its own decision on
whether to use the optimization.

This patch also renames the cpu-errata-workarounds.md to
cpu-specific-build-macros.md as this facilitates documentation
of both CPU Specific errata and CPU Specific Optimization
build macros.

Change-Id: I299b9fe79e9a7e08e8a0dffb7d345f9a00a71480
2014-10-29 17:39:59 +00:00
Soby Mathew b1a9631d81 Optimize barrier usage during Cortex-A57 power down
This the patch replaces the DSB SY with DSB ISH
after disabling L2 prefetches during the Cortex-A57
power down sequence.

Change-Id: I048d12d830c1b974b161224eff079fb9f8ecf52d
2014-10-29 17:38:56 +00:00
Soby Mathew 7395a725ae Apply errata workarounds only when major/minor revisions match.
Prior to this patch, the errata workarounds were applied for any version
of the CPU in the release build and in the debug build an assert
failure resulted when the revision did not match. This patch applies
errata workarounds in the Cortex-A57 reset handler only if the 'variant'
and 'revision' fields read from the MIDR_EL1 match. In the debug build,
a warning message is printed for each errata workaround which is not
applied.

The patch modifies the register usage in 'reset_handler` so
as to adhere to ARM procedure calling standards.

Fixes ARM-software/tf-issues#242

Change-Id: I51b1f876474599db885afa03346e38a476f84c29
2014-10-29 17:38:56 +00:00
Soby Mathew 8e85791677 Add support for level specific cache maintenance operations
This patch adds level specific cache maintenance functions
to cache_helpers.S. The new functions 'dcsw_op_levelx',
where '1 <= x <= 3', allow to perform cache maintenance by
set/way for that particular level of cache.  With this patch,
functions to support cache maintenance upto level 3 have
been implemented since it is the highest cache level for
most ARM SoCs.

These functions are now utilized in CPU specific power down
sequences to implement them as mandated by processor specific
technical reference manual.

Change-Id: Icd90ce6b51cff5a12863bcda01b93601417fd45c
2014-10-29 17:38:56 +00:00
Soby Mathew d9bdaf2d98 Add support for selected Cortex-A57 errata workarounds
This patch adds workarounds for selected errata which affect the Cortex-A57 r0p0
part. Each workaround has a build time flag which should be used by the platform
port to enable or disable the corresponding workaround. The workarounds are
disabled by default. An assertion is raised if the platform enables a workaround
which does not match the CPU revision at runtime.

Change-Id: I9ae96b01c6ff733d04dc733bd4e67dbf77b29fb0
2014-08-20 19:14:31 +01:00
Soby Mathew d3f70af6e0 Add CPU specific crash reporting handlers
This patch adds handlers for dumping Cortex-A57 and Cortex-A53 specific register
state to the CPU specific operations framework. The contents of CPUECTLR_EL1 are
dumped currently.

Change-Id: I63d3dbfc4ac52fef5e25a8cf6b937c6f0975c8ab
2014-08-20 19:14:31 +01:00
Soby Mathew add403514d Add CPU specific power management operations
This patch adds CPU core and cluster power down sequences to the CPU specific
operations framework introduced in a earlier patch. Cortex-A53, Cortex-A57 and
generic AEM sequences have been added. The latter is suitable for the
Foundation and Base AEM FVPs. A pointer to each CPU's operations structure is
saved in the per-cpu data so that it can be easily accessed during power down
seqeunces.

An optional platform API has been introduced to allow a platform to disable the
Accelerator Coherency Port (ACP) during a cluster power down sequence. The weak
definition of this function (plat_disable_acp()) does not take any action. It
should be overriden with a strong definition if the ACP is present on a
platform.

Change-Id: I8d09bd40d2f528a28d2d3f19b77101178778685d
2014-08-20 19:14:31 +01:00
Soby Mathew 9b47684170 Introduce framework for CPU specific operations
This patch introduces a framework which will allow CPUs to perform
implementation defined actions after a CPU reset, during a CPU or cluster power
down, and when a crash occurs. CPU specific reset handlers have been implemented
in this patch. Other handlers will be implemented in subsequent patches.

Also moved cpu_helpers.S to the new directory lib/cpus/aarch64/.

Change-Id: I1ca1bade4d101d11a898fb30fea2669f9b37b956
2014-08-20 19:13:25 +01:00