powerpc: Add support for context switching the TAR register

This patch adds support for enabling and context switching the Target
Address Register in Power8. The TAR is a new special purpose register
that can be used for computed branches with the bctar[l] (branch
conditional to TAR) instruction in the same manner as the count and link
registers.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Ian Munsie
2013-02-07 15:46:58 +00:00
committed by Benjamin Herrenschmidt
parent 14b6f00f8a
commit 2468dcf641
6 changed files with 38 additions and 1 deletions

View File

@@ -257,6 +257,9 @@ struct thread_struct {
int dscr_inherit;
unsigned long ppr; /* used to save/restore SMT priority */
#endif
#ifdef CONFIG_PPC_BOOK3S_64
unsigned long tar;
#endif
};
#define ARCH_MIN_TASKALIGN 16