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2923f5ea77
This patch includes the exception/interrupt entries, pt_reg structure and
related accessors.
/* Unaligned accessing handling*/
Andes processors cannot load/store information which is not naturally
aligned on the bus, i.e., loading a 4 byte data whose start address must
be divisible by 4. If unaligned data accessing is happened, data
unaligned exception will be triggered and user will get SIGSEGV or
kernel oops according to the unaligned address. In order to make user be
able to load/store data from an unaligned address, software load/store
emulation is implemented in arch/nds32/mm/alignment.c to address data
unaligned exception.
Unaligned accessing handling is disabled by default because it is not a
normal case. User can enable this feature by following steps.
A. Compile time:
1. Enable kernel config CONFIG_ALIGNMENT_TRAP
B. Run time:
1. Enter /proc/sys/nds32/unaligned_acess folder
2. Write 1 to file enable_mode to enable unaligned accessing
handling. User can disable it by writing 0 to this file.
3. Write 1 to file debug to show which unaligned address is under
processing. User can disable it by writing 0 to this file.
However, unaligned accessing handler cannot work if this unaligned
address is not accessible such as protection violation. On this
condition, the default behaviors for addressing data unaligned exception
still happen
Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.