0bbff9ed81
Armv8.9/9.4 PMUv3.9 adds per counter EL0 access controls. Per counter access is enabled with the UEN bit in PMUSERENR_EL1 register. Individual counters are enabled/disabled in the PMUACR_EL1 register. When UEN is set, the CR/ER bits control EL0 write access and must be set to disable write access. With the access controls, the clearing of unused counters can be skipped. KVM also configures PMUSERENR_EL1 in order to trap to EL2. UEN does not need to be set for it since only PMUv3.5 is exposed to guests. Signed-off-by: Rob Herring (Arm) <robh@kernel.org> Link: https://lore.kernel.org/r/20241002184326.1105499-1-robh@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.