From 1739ea9e13e636590dd56c2f4ca85e783da512e7 Mon Sep 17 00:00:00 2001 From: Sam bobroff Date: Wed, 21 May 2014 16:32:38 +1000 Subject: powerpc: Fix regression of per-CPU DSCR setting Since commit "efcac65 powerpc: Per process DSCR + some fixes (try#4)" it is no longer possible to set the DSCR on a per-CPU basis. The old behaviour was to minipulate the DSCR SPR directly but this is no longer sufficient: the value is quickly overwritten by context switching. This patch stores the per-CPU DSCR value in a kernel variable rather than directly in the SPR and it is used whenever a process has not set the DSCR itself. The sysfs interface (/sys/devices/system/cpu/cpuN/dscr) is unchanged. Writes to the old global default (/sys/devices/system/cpu/dscr_default) now set all of the per-CPU values and reads return the last written value. The new per-CPU default is added to the paca_struct and is used everywhere outside of sysfs.c instead of the old global default. Signed-off-by: Sam Bobroff Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/paca.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/powerpc/include/asm/paca.h') diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index 8e956a0b6e85..bb0bd25f20d0 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -92,7 +92,10 @@ struct paca_struct { struct slb_shadow *slb_shadow_ptr; struct dtl_entry *dispatch_log; struct dtl_entry *dispatch_log_end; +#endif /* CONFIG_PPC_STD_MMU_64 */ + u64 dscr_default; /* per-CPU default DSCR */ +#ifdef CONFIG_PPC_STD_MMU_64 /* * Now, starting in cacheline 2, the exception save areas */ -- cgit