]> git.ipfire.org Git - people/arne_f/kernel.git/commit
x86/cpu/cyrix: Use correct macros for Cyrix calls on Geode processors
authorMatthew Whitehead <tedheadster@gmail.com>
Thu, 14 Mar 2019 20:46:00 +0000 (16:46 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 20 Apr 2019 07:07:50 +0000 (09:07 +0200)
commit2e91bfe2a83d32321171e17cdaa38b8cbe503f7c
tree274ffda05bc18d6033ad1c00e8a650376e53e721
parentec1fdc02cc255f5021f52e3bf90044099d9eba67
x86/cpu/cyrix: Use correct macros for Cyrix calls on Geode processors

[ Upstream commit 18fb053f9b827bd98cfc64f2a35df8ab19745a1d ]

There are comments in processor-cyrix.h advising you to _not_ make calls
using the deprecated macros in this style:

  setCx86_old(CX86_CCR4, getCx86_old(CX86_CCR4) | 0x80);

This is because it expands the macro into a non-functioning calling
sequence. The calling order must be:

  outb(CX86_CCR2, 0x22);
  inb(0x23);

From the comments:

 * When using the old macros a line like
 *   setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);
 * gets expanded to:
 *  do {
 *    outb((CX86_CCR2), 0x22);
 *    outb((({
 *        outb((CX86_CCR2), 0x22);
 *        inb(0x23);
 *    }) | 0x88), 0x23);
 *  } while (0);

The new macros fix this problem, so use them instead. Tested on an
actual Geode processor.

Signed-off-by: Matthew Whitehead <tedheadster@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: luto@kernel.org
Link: https://lkml.kernel.org/r/1552596361-8967-2-git-send-email-tedheadster@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
arch/x86/kernel/cpu/cyrix.c