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Filename Latest commit message Latest commit date
Christophe Leroy c691b4b83b powerpc: rewrite LOAD_REG_IMMEDIATE() as an intelligent macro
Today LOAD_REG_IMMEDIATE() is a basic #define which loads all
parts on a value into a register, including the parts that are NUL.

This means always 2 instructions on PPC32 and always 5 instructions
on PPC64. And those instructions cannot run in parallele as they are
updating the same register.

Ex: LOAD_REG_IMMEDIATE(r1,THREAD_SIZE) in head_64.S results in:

3c 20 00 00     lis     r1,0
60 21 00 00     ori     r1,r1,0
78 21 07 c6     rldicr  r1,r1,32,31
64 21 00 00     oris    r1,r1,0
60 21 40 00     ori     r1,r1,16384

Rewrite LOAD_REG_IMMEDIATE() with GAS macro in order to skip
the parts that are NUL.

Rename existing LOAD_REG_IMMEDIATE() as LOAD_REG_IMMEDIATE_SYM()
and use that one for loading value of symbols which are not known
at compile time.

Now LOAD_REG_IMMEDIATE(r1,THREAD_SIZE) in head_64.S results in:

38 20 40 00     li      r1,16384

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d60ce8dd3a383c7adbfc322bf1d53d81724a6000.1566311636.git.christophe.leroy@c-s.fr
2019-08-27 13:03:36 +10:00
arch powerpc: rewrite LOAD_REG_IMMEDIATE() as an intelligent macro 2019-08-27 13:03:36 +10:00
block
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Documentation powerpc: Document xmon options 2019-08-22 23:12:47 +10:00
drivers Merge branch 'fixes' into next 2019-08-19 12:43:13 +10:00
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include extable: Add function to search only kernel exception table 2019-08-21 22:23:48 +10:00
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kernel extable: Add function to search only kernel exception table 2019-08-21 22:23:48 +10:00
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security meminit fix 2019-07-28 12:33:15 -07:00
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Makefile Linux 5.3-rc2 2019-07-28 12:47:02 -07:00
README

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.