From 895796a8ab548fe03b6fea410dcb1b86e1913708 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Mon, 24 Jan 2011 13:25:55 +1100 Subject: [PATCH] powerpc: Initialize LPCR:DPFD on power7 to a sane default This sets the default data stream prefetch size for operating systems that don't set their own value in DSCR. We use 4 which is "medium". Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/cpu_setup_power7.S | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/powerpc/kernel/cpu_setup_power7.S b/arch/powerpc/kernel/cpu_setup_power7.S index e801ef15d6d0..2390f6f7c478 100644 --- a/arch/powerpc/kernel/cpu_setup_power7.S +++ b/arch/powerpc/kernel/cpu_setup_power7.S @@ -54,6 +54,7 @@ __init_LPCR: * * LPES = 0b01 (HSRR0/1 used for 0x500) * PECE = 0b111 + * DPFD = 4 * * Other bits untouched for now */ @@ -61,6 +62,12 @@ __init_LPCR: ori r3,r3,(LPCR_LPES0|LPCR_LPES1) xori r3,r3, LPCR_LPES0 ori r3,r3,(LPCR_PECE0|LPCR_PECE1|LPCR_PECE2) + li r5,7 + sldi r5,r5,LPCR_DPFD_SH + andc r3,r3,r5 + li r5,4 + sldi r5,r5,LPCR_DPFD_SH + or r3,r3,r5 mtspr SPRN_LPCR,r3 isync blr