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powerpc/mm: Convert virtual address to vpn

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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 <paulus@samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Aneesh Kumar K.V 2012-09-10 02:52:50 +00:00 • committed by Benjamin Herrenschmidt
parent dcda287a9b
commit 5524a27d39
16 changed files with 324 additions and 240 deletions
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78
arch/powerpc/include/asm/mmu-hash64.h
View file

@ -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;
}