powerpc: Define ppr in thread_struct

[PATCH 4/6] powerpc: Define ppr in thread_struct

ppr in thread_struct is used to save PPR and restore it before process exits
from kernel.

This patch sets the default priority to 3 when tasks are created such
that users can use 4 for higher priority tasks.

Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Haren Myneni 2012-12-06 21:49:56 +00:00 committed by Benjamin Herrenschmidt
parent a09688cd23
commit 9277924559
3 changed files with 15 additions and 0 deletions

View File

@ -18,6 +18,16 @@
#define TS_FPRWIDTH 1
#endif
#ifdef CONFIG_PPC64
/* Default SMT priority is set to 3. Use 11- 13bits to save priority. */
#define PPR_PRIORITY 3
#ifdef __ASSEMBLY__
#define INIT_PPR (PPR_PRIORITY << 50)
#else
#define INIT_PPR ((u64)PPR_PRIORITY << 50)
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_PPC64 */
#ifndef __ASSEMBLY__
#include <linux/compiler.h>
#include <linux/cache.h>
@ -245,6 +255,7 @@ struct thread_struct {
#ifdef CONFIG_PPC64
unsigned long dscr;
int dscr_inherit;
unsigned long ppr; /* used to save/restore SMT priority */
#endif
};
@ -278,6 +289,7 @@ struct thread_struct {
.fpr = {{0}}, \
.fpscr = { .val = 0, }, \
.fpexc_mode = 0, \
.ppr = INIT_PPR, \
}
#endif

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@ -77,6 +77,7 @@ int main(void)
DEFINE(NMI_MASK, NMI_MASK);
DEFINE(THREAD_DSCR, offsetof(struct thread_struct, dscr));
DEFINE(THREAD_DSCR_INHERIT, offsetof(struct thread_struct, dscr_inherit));
DEFINE(TASKTHREADPPR, offsetof(struct task_struct, thread.ppr));
#else
DEFINE(THREAD_INFO, offsetof(struct task_struct, stack));
#endif /* CONFIG_PPC64 */

View File

@ -813,6 +813,8 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
p->thread.dscr_inherit = current->thread.dscr_inherit;
p->thread.dscr = current->thread.dscr;
}
if (cpu_has_feature(CPU_FTR_HAS_PPR))
p->thread.ppr = INIT_PPR;
#endif
/*
* The PPC64 ABI makes use of a TOC to contain function