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 <benh@kernel.crashing.org>
This commit is contained in:
Benjamin Herrenschmidt 2011-01-24 13:25:55 +11:00
parent 673b189a2e
commit 895796a8ab

View file

@ -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