Commit 97b3be1e authored by Alistair Popple's avatar Alistair Popple Committed by Benjamin Herrenschmidt

powerpc/ppc476: Disable BTAC

This patch disables the branch target address CAM which under specific
circumstances may cause the processor to skip execution of 1-4
instructions. This fixes IBM Erratum #47.
Signed-off-by: default avatarAlistair Popple <alistair@popple.id.au>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 763fe0ad
...@@ -1210,10 +1210,12 @@ clear_utlb_entry: ...@@ -1210,10 +1210,12 @@ clear_utlb_entry:
/* We configure icbi to invalidate 128 bytes at a time since the /* We configure icbi to invalidate 128 bytes at a time since the
* current 32-bit kernel code isn't too happy with icache != dcache * current 32-bit kernel code isn't too happy with icache != dcache
* block size * block size. We also disable the BTAC as this can cause errors
* in some circumstances (see IBM Erratum 47).
*/ */
mfspr r3,SPRN_CCR0 mfspr r3,SPRN_CCR0
oris r3,r3,0x0020 oris r3,r3,0x0020
ori r3,r3,0x0040
mtspr SPRN_CCR0,r3 mtspr SPRN_CCR0,r3
isync isync
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment