From 048ee0993ec8360abb0b51bdf8f8721e9ed62ec4 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Mon, 10 Sep 2012 02:52:55 +0000 Subject: powerpc/mm: Add 64TB support Increase max addressable range to 64TB. This is not tested on real hardware yet. Reviewed-by: Paul Mackerras Signed-off-by: Aneesh Kumar K.V Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/mmu-hash64.h | 42 +++++++++++++++++++++++++++-------- 1 file changed, 33 insertions(+), 9 deletions(-) (limited to 'arch/powerpc/include/asm/mmu-hash64.h') diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h index 7cbd541f915..23730ee65aa 100644 --- a/arch/powerpc/include/asm/mmu-hash64.h +++ b/arch/powerpc/include/asm/mmu-hash64.h @@ -370,17 +370,21 @@ extern void slb_set_size(u16 size); * (head.S) and ASM_VSID_SCRAMBLE (below) are changed accordingly. */ -#define VSID_MULTIPLIER_256M ASM_CONST(200730139) /* 28-bit prime */ -#define VSID_BITS_256M 36 +/* + * This should be computed such that protovosid * vsid_mulitplier + * doesn't overflow 64 bits. It should also be co-prime to vsid_modulus + */ +#define VSID_MULTIPLIER_256M ASM_CONST(12538073) /* 24-bit prime */ +#define VSID_BITS_256M 38 #define VSID_MODULUS_256M ((1UL<= PAGE_OFFSET */ +/* + * This is only valid for addresses >= PAGE_OFFSET + * The proto-VSID space is divided into two class + * User: 0 to 2^(CONTEXT_BITS + USER_ESID_BITS) -1 + * kernel: 2^(CONTEXT_BITS + USER_ESID_BITS) to 2^(VSID_BITS) - 1 + * + * With KERNEL_START at 0xc000000000000000, the proto vsid for + * the kernel ends up with 0xc00000000 (36 bits). With 64TB + * support we need to have kernel proto-VSID in the + * [2^37 to 2^38 - 1] range due to the increased USER_ESID_BITS. + */ static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize) { - if (ssize == MMU_SEGSIZE_256M) - return vsid_scramble(ea >> SID_SHIFT, 256M); - return vsid_scramble(ea >> SID_SHIFT_1T, 1T); + unsigned long proto_vsid; + /* + * We need to make sure proto_vsid for the kernel is + * >= 2^(CONTEXT_BITS + USER_ESID_BITS[_1T]) + */ + if (ssize == MMU_SEGSIZE_256M) { + proto_vsid = ea >> SID_SHIFT; + proto_vsid |= (1UL << (CONTEXT_BITS + USER_ESID_BITS)); + return vsid_scramble(proto_vsid, 256M); + } + proto_vsid = ea >> SID_SHIFT_1T; + proto_vsid |= (1UL << (CONTEXT_BITS + USER_ESID_BITS_1T)); + return vsid_scramble(proto_vsid, 1T); } /* Returns the segment size indicator for a user address */ -- cgit v1.2.3-70-g09d2