5cd6fa6de5
In __cpu_setup we conditionally manipulate the TCR_EL1 value in x10 after previously using x10 as a scratch register for unrelated temporary variables. To make this a bit clearer, let's move the TCR_EL1 value into a named register `tcr`. To simplify the register allocation, this is placed in the highest available caller-saved scratch register, tcr. Following the example of `mair`, we initialise the register with the default value prior to any feature discovery, and write it to MAIR_EL1 after all feature discovery is complete, which allows us to simplify the featuere discovery code. The existing `mte_tcr` register is no longer needed, and is replaced by the use of x10 as a temporary, matching the rest of the MTE feature discovery assembly in __cpu_setup. As x20 is no longer used, the function is now AAPCS compliant, as we've generally aimed for in our assembly functions. There should be no functional change as as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210326180137.43119-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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 Restructured Text 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.