Restricts MPAM to only NS world and enables trap to EL3 for access of
MPAM registers from lower ELs of Secure and Realm world.
This patch removes MPAM enablement from global context and adds it to
EL3 State context which enables/disables MPAM during world switches.
Renamed ENABLE_MPAM_FOR_LOWER_ELS to ENABLE_FEAT_MPAM and
removed mpam_init_el3() as RESET behaviour is trapping.
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I131f9dba5df236a71959b2d425ee11af7f3c38c4
Combining the EL2 and EL3 enablement code necessitates that it must be
called at el3_exit, which is the only place with enough context to make
the decision of what needs to be set.
Decouple them to allow them to be called from elsewhere.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I147764c42771e7d4100699ec8fae98dac0a505c0
For builds where we don't have a certain feature enabled, we provide
empty stub xxx_enable() functions in a header file. This way we
avoid #ifdef's in the code, and can call the enable function
unconditionally. When compiling with -O1 or higher, the compiler will
even optimise out the whole call, so the symbol will never make it into
any object file.
When compiling with optimisations turned off, the function stub will
survive, and could make it into multiple object files, which would lead
to a multiple definitons error.
Avoid this by defining those stub functions as "static inline". The
"static" will avoid the multiple definitions problems, the "inline" will
avoid a potential compiler warning about unused functions.
This patterns is used extensively in the Linux kernel.
Change-Id: Iad07bb946aab372587c83f2423b4983bf3817990
Reported-by: Chris Kay <chris.kay@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
At the moment we only support FEAT_MPAM to be either unconditionally
compiled in, or to be not supported at all.
Add support for runtime detection (ENABLE_MPAM_FOR_LOWER_ELS=2), by
splitting get_mpam_version() into an ID register reading
function and a second function to report the support status. That
function considers both build time settings and runtime information (if
needed), and is used before we access MPAM related registers.
Also move the context saving code from assembly to C, and use the new
is_feat_mpam_supported() function to guard its execution.
ENABLE_MPAM_FOR_LOWER_ELS defaults to 0, so add a stub enable function
to cover builds with compiler optimisations turned off. The unused
mpam_enable() function call will normally be optimised away (because it
would never be called), but with -O0 the compiler will leave the symbol
in the object file.
Change-Id: I531d87cb855a7c43471f861f625b5a6d4bc61313
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Memory Partitioning And Monitoring is an Armv8.4 feature that enables
various memory system components and resources to define partitions.
Software running at various ELs can then assign themselves to the
desired partition to control their performance aspects.
With this patch, when ENABLE_MPAM_FOR_LOWER_ELS is set to 1, EL3 allows
lower ELs to access their own MPAM registers without trapping to EL3.
This patch however doesn't make use of partitioning in EL3; platform
initialisation code should configure and use partitions in EL3 if
required.
Change-Id: I5a55b6771ccaa0c1cffc05543d2116b60cbbcdcd
Co-authored-by: James Morse <james.morse@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
