dfb12071dd
FAKE_RET_FROM_EXCEPTION drops down to pure kernel mode. It currently has
an 8 byte instruction which can be replaced with 4 byte BSET
This is applicable to both ARCv2 and ARCv3 entr code.
ARCv2 current
------------
00000804 <EV_Trap>:
...
874: 216a 1280 lr r9,[status32]
878: 2146 1809 bic r9,r9,0x20
87c: 2105 1f89 8000 0000 or r9,r9,0x80000000
^^^^^^^^^
884: 2029 8240 kflag r9
ARCv2 after
----------
000007e0 <EV_Trap>:
...
850: 216a 1280 lr r9,[status32]
854: 2150 1149 bclr r9,r9,0x5
858: 214f 17c9 bset r9,r9,0x1f
85c: 2029 8240 kflag r9
Signed-off-by: Vineet Gupta <vgupta@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 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.