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powerpc/mm: Add 64TB support

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Increase max addressable range to 64TB. This is not tested on
real hardware yet.

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 02:52:55 +00:00 • committed by Benjamin Herrenschmidt
parent 735cafc32b
commit 048ee0993e
7 changed files with 54 additions and 16 deletions
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42
arch/powerpc/include/asm/mmu-hash64.h
View file

@ -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<<VSID_BITS_256M)-1)
#define VSID_MULTIPLIER_1T ASM_CONST(12538073) /* 24-bit prime */
#define VSID_BITS_1T 24
#define VSID_BITS_1T 26
#define VSID_MODULUS_1T ((1UL<<VSID_BITS_1T)-1)
#define CONTEXT_BITS 19
#define USER_ESID_BITS 16
#define USER_ESID_BITS_1T 4
#define USER_ESID_BITS 18
#define USER_ESID_BITS_1T 6
#define USER_VSID_RANGE (1UL << (USER_ESID_BITS + SID_SHIFT))
@ -500,12 +504,32 @@ typedef struct {
})
#endif /* 1 */
/* This is only valid for addresses >= 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 */