From 5524a27d39b68770f203d8d42eb5a95dde4933bc Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Mon, 10 Sep 2012 02:52:50 +0000 Subject: powerpc/mm: Convert virtual address to vpn This patch convert different functions to take virtual page number instead of virtual address. Virtual page number is virtual address shifted right by VPN_SHIFT (12) bits. This enable us to have an address range of upto 76 bits. Reviewed-by: Paul Mackerras Signed-off-by: Aneesh Kumar K.V Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/mmu-hash64.h | 78 +++++++++++++++++++++++++++-------- 1 file changed, 61 insertions(+), 17 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 1c65a59881ea..6aeb4986a373 100644 --- a/arch/powerpc/include/asm/mmu-hash64.h +++ b/arch/powerpc/include/asm/mmu-hash64.h @@ -154,9 +154,25 @@ struct mmu_psize_def #define MMU_SEGSIZE_256M 0 #define MMU_SEGSIZE_1T 1 +/* + * encode page number shift. + * in order to fit the 78 bit va in a 64 bit variable we shift the va by + * 12 bits. This enable us to address upto 76 bit va. + * For hpt hash from a va we can ignore the page size bits of va and for + * hpte encoding we ignore up to 23 bits of va. So ignoring lower 12 bits ensure + * we work in all cases including 4k page size. + */ +#define VPN_SHIFT 12 #ifndef __ASSEMBLY__ +static inline int segment_shift(int ssize) +{ + if (ssize == MMU_SEGSIZE_256M) + return SID_SHIFT; + return SID_SHIFT_1T; +} + /* * The current system page and segment sizes */ @@ -179,19 +195,40 @@ extern unsigned long tce_alloc_start, tce_alloc_end; */ extern int mmu_ci_restrictions; +/* + * This computes the AVPN and B fields of the first dword of a HPTE, + * for use when we want to match an existing PTE. The bottom 7 bits + * of the returned value are zero. + */ +static inline unsigned long hpte_encode_avpn(unsigned long vpn, int psize, + int ssize) +{ + unsigned long v; + /* + * The AVA field omits the low-order 23 bits of the 78 bits VA. + * These bits are not needed in the PTE, because the + * low-order b of these bits are part of the byte offset + * into the virtual page and, if b < 23, the high-order + * 23-b of these bits are always used in selecting the + * PTEGs to be searched + */ + v = (vpn >> (23 - VPN_SHIFT)) & ~(mmu_psize_defs[psize].avpnm); + v <<= HPTE_V_AVPN_SHIFT; + v |= ((unsigned long) ssize) << HPTE_V_SSIZE_SHIFT; + return v; +} + /* * This function sets the AVPN and L fields of the HPTE appropriately * for the page size */ -static inline unsigned long hpte_encode_v(unsigned long va, int psize, - int ssize) +static inline unsigned long hpte_encode_v(unsigned long vpn, + int psize, int ssize) { unsigned long v; - v = (va >> 23) & ~(mmu_psize_defs[psize].avpnm); - v <<= HPTE_V_AVPN_SHIFT; + v = hpte_encode_avpn(vpn, psize, ssize); if (psize != MMU_PAGE_4K) v |= HPTE_V_LARGE; - v |= ((unsigned long) ssize) << HPTE_V_SSIZE_SHIFT; return v; } @@ -216,30 +253,37 @@ static inline unsigned long hpte_encode_r(unsigned long pa, int psize) } /* - * Build a VA given VSID, EA and segment size + * Build a VPN_SHIFT bit shifted va given VSID, EA and segment size. */ -static inline unsigned long hpt_va(unsigned long ea, unsigned long vsid, - int ssize) +static inline unsigned long hpt_vpn(unsigned long ea, + unsigned long vsid, int ssize) { - if (ssize == MMU_SEGSIZE_256M) - return (vsid << 28) | (ea & 0xfffffffUL); - return (vsid << 40) | (ea & 0xffffffffffUL); + unsigned long mask; + int s_shift = segment_shift(ssize); + + mask = (1ul << (s_shift - VPN_SHIFT)) - 1; + return (vsid << (s_shift - VPN_SHIFT)) | ((ea >> VPN_SHIFT) & mask); } /* * This hashes a virtual address */ - -static inline unsigned long hpt_hash(unsigned long va, unsigned int shift, - int ssize) +static inline unsigned long hpt_hash(unsigned long vpn, + unsigned int shift, int ssize) { + int mask; unsigned long hash, vsid; + /* VPN_SHIFT can be atmost 12 */ if (ssize == MMU_SEGSIZE_256M) { - hash = (va >> 28) ^ ((va & 0x0fffffffUL) >> shift); + mask = (1ul << (SID_SHIFT - VPN_SHIFT)) - 1; + hash = (vpn >> (SID_SHIFT - VPN_SHIFT)) ^ + ((vpn & mask) >> (shift - VPN_SHIFT)); } else { - vsid = va >> 40; - hash = vsid ^ (vsid << 25) ^ ((va & 0xffffffffffUL) >> shift); + mask = (1ul << (SID_SHIFT_1T - VPN_SHIFT)) - 1; + vsid = vpn >> (SID_SHIFT_1T - VPN_SHIFT); + hash = vsid ^ (vsid << 25) ^ + ((vpn & mask) >> (shift - VPN_SHIFT)) ; } return hash & 0x7fffffffffUL; } -- cgit v1.2.3