This patch introduces some debug assertions in the function
psci_cpu_on_start() to check the arguments it receives are
valid.
Change-Id: If4d23c9f668fb46f2d18c5e2ed1929498cc6736b
When a CPU is powered down using PSCI CPU OFF API, it disables its caches
and updates its `aff_info_state` to OFF. The corresponding cache line is
invalidated by the CPU so that the update will be observed by other CPUs
running with caches enabled. There is a possibility that another CPU
which has been trying to turn ON this CPU via PSCI CPU ON API,
has already seen the update to `aff_info_state` and proceeds to update
the state to ON_PENDING prior to the cache invalidation. This may result
in the update of the state to ON_PENDING being discarded.
This patch fixes this issue by making sure that the update of `aff_info_state`
to ON_PENDING sticks by reading back the value after the cache flush and
retrying it if not updated. The patch also adds a dsbish() to
`psci_do_cpu_off()` to ensure ordering of the update to `aff_info_state`
prior to cache line invalidation.
FixesARM-software/tf-issues#349
Change-Id: I225de99957fe89871f8c57bcfc243956e805dcca
On the ARMv8 architecture, cache maintenance operations by set/way on the last
level of integrated cache do not affect the system cache. This means that such a
flush or clean operation could result in the data being pushed out to the system
cache rather than main memory. Another CPU could access this data before it
enables its data cache or MMU. Such accesses could be serviced from the main
memory instead of the system cache. If the data in the sysem cache has not yet
been flushed or evicted to main memory then there could be a loss of
coherency. The only mechanism to guarantee that the main memory will be updated
is to use cache maintenance operations to the PoC by MVA(See section D3.4.11
(System level caches) of ARMv8-A Reference Manual (Issue A.g/ARM DDI0487A.G).
This patch removes the reliance of Trusted Firmware on the flush by set/way
operation to ensure visibility of data in the main memory. Cache maintenance
operations by MVA are now used instead. The following are the broad category of
changes:
1. The RW areas of BL2/BL31/BL32 are invalidated by MVA before the C runtime is
initialised. This ensures that any stale cache lines at any level of cache
are removed.
2. Updates to global data in runtime firmware (BL31) by the primary CPU are made
visible to secondary CPUs using a cache clean operation by MVA.
3. Cache maintenance by set/way operations are only used prior to power down.
NOTE: NON-UPSTREAM TRUSTED FIRMWARE CODE SHOULD MAKE EQUIVALENT CHANGES IN
ORDER TO FUNCTION CORRECTLY ON PLATFORMS WITH SUPPORT FOR SYSTEM CACHES.
FixesARM-software/tf-issues#205
Change-Id: I64f1b398de0432813a0e0881d70f8337681f6e9a
This patch reworks the PSCI generic implementation to conform to ARM
Trusted Firmware coding guidelines as described here:
https://github.com/ARM-software/arm-trusted-firmware/wiki
This patch also reviews the use of signed data types within PSCI
Generic code and replaces them with their unsigned counterparts wherever
they are not appropriate. The PSCI_INVALID_DATA macro which was defined
to -1 is now replaced with PSCI_INVALID_PWR_LVL macro which is defined
to PLAT_MAX_PWR_LVL + 1.
Change-Id: Iaea422d0e46fc314e0b173c2b4c16e0d56b2515a
This commit does the switch to the new PSCI framework implementation replacing
the existing files in PSCI folder with the ones in PSCI1.0 folder. The
corresponding makefiles are modified as required for the new implementation.
The platform.h header file is also is switched to the new one
as required by the new frameworks. The build flag ENABLE_PLAT_COMPAT defaults
to 1 to enable compatibility layer which let the existing platform ports to
continue to build and run with minimal changes.
The default weak implementation of platform_get_core_pos() is now removed from
platform_helpers.S and is provided by the compatibility layer.
Note: The Secure Payloads and their dispatchers still use the old platform
and framework APIs and hence it is expected that the ENABLE_PLAT_COMPAT build
flag will remain enabled in subsequent patch. The compatibility for SPDs using
the older APIs on platforms migrated to the new APIs will be added in the
following patch.
Change-Id: I18c51b3a085b564aa05fdd98d11c9f3335712719
Sandrine Bailleux
Soby Mathew
Achin Gupta