344 lines
10 KiB
C
344 lines
10 KiB
C
/*
|
|
* PowerPC memory management structures
|
|
*
|
|
* Dave Engebretsen & Mike Corrigan <{engebret|mikejc}@us.ibm.com>
|
|
* PPC64 rework.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#ifndef _PPC64_MMU_H_
|
|
#define _PPC64_MMU_H_
|
|
|
|
#include <linux/config.h>
|
|
#include <asm/page.h>
|
|
|
|
/*
|
|
* Segment table
|
|
*/
|
|
|
|
#define STE_ESID_V 0x80
|
|
#define STE_ESID_KS 0x20
|
|
#define STE_ESID_KP 0x10
|
|
#define STE_ESID_N 0x08
|
|
|
|
#define STE_VSID_SHIFT 12
|
|
|
|
/* Location of cpu0's segment table */
|
|
#define STAB0_PAGE 0x9
|
|
#define STAB0_PHYS_ADDR (STAB0_PAGE<<PAGE_SHIFT)
|
|
#define STAB0_VIRT_ADDR (KERNELBASE+STAB0_PHYS_ADDR)
|
|
|
|
/*
|
|
* SLB
|
|
*/
|
|
|
|
#define SLB_NUM_BOLTED 3
|
|
#define SLB_CACHE_ENTRIES 8
|
|
|
|
/* Bits in the SLB ESID word */
|
|
#define SLB_ESID_V ASM_CONST(0x0000000008000000) /* valid */
|
|
|
|
/* Bits in the SLB VSID word */
|
|
#define SLB_VSID_SHIFT 12
|
|
#define SLB_VSID_KS ASM_CONST(0x0000000000000800)
|
|
#define SLB_VSID_KP ASM_CONST(0x0000000000000400)
|
|
#define SLB_VSID_N ASM_CONST(0x0000000000000200) /* no-execute */
|
|
#define SLB_VSID_L ASM_CONST(0x0000000000000100) /* largepage 16M */
|
|
#define SLB_VSID_C ASM_CONST(0x0000000000000080) /* class */
|
|
|
|
#define SLB_VSID_KERNEL (SLB_VSID_KP|SLB_VSID_C)
|
|
#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS)
|
|
|
|
/*
|
|
* Hash table
|
|
*/
|
|
|
|
#define HPTES_PER_GROUP 8
|
|
|
|
/* Values for PP (assumes Ks=0, Kp=1) */
|
|
/* pp0 will always be 0 for linux */
|
|
#define PP_RWXX 0 /* Supervisor read/write, User none */
|
|
#define PP_RWRX 1 /* Supervisor read/write, User read */
|
|
#define PP_RWRW 2 /* Supervisor read/write, User read/write */
|
|
#define PP_RXRX 3 /* Supervisor read, User read */
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
/* Hardware Page Table Entry */
|
|
typedef struct {
|
|
unsigned long avpn:57; /* vsid | api == avpn */
|
|
unsigned long : 2; /* Software use */
|
|
unsigned long bolted: 1; /* HPTE is "bolted" */
|
|
unsigned long lock: 1; /* lock on pSeries SMP */
|
|
unsigned long l: 1; /* Virtual page is large (L=1) or 4 KB (L=0) */
|
|
unsigned long h: 1; /* Hash function identifier */
|
|
unsigned long v: 1; /* Valid (v=1) or invalid (v=0) */
|
|
} Hpte_dword0;
|
|
|
|
typedef struct {
|
|
unsigned long pp0: 1; /* Page protection bit 0 */
|
|
unsigned long ts: 1; /* Tag set bit */
|
|
unsigned long rpn: 50; /* Real page number */
|
|
unsigned long : 2; /* Reserved */
|
|
unsigned long ac: 1; /* Address compare */
|
|
unsigned long r: 1; /* Referenced */
|
|
unsigned long c: 1; /* Changed */
|
|
unsigned long w: 1; /* Write-thru cache mode */
|
|
unsigned long i: 1; /* Cache inhibited */
|
|
unsigned long m: 1; /* Memory coherence required */
|
|
unsigned long g: 1; /* Guarded */
|
|
unsigned long n: 1; /* No-execute */
|
|
unsigned long pp: 2; /* Page protection bits 1:2 */
|
|
} Hpte_dword1;
|
|
|
|
typedef struct {
|
|
char padding[6]; /* padding */
|
|
unsigned long : 6; /* padding */
|
|
unsigned long flags: 10; /* HPTE flags */
|
|
} Hpte_dword1_flags;
|
|
|
|
typedef struct {
|
|
union {
|
|
unsigned long dword0;
|
|
Hpte_dword0 dw0;
|
|
} dw0;
|
|
|
|
union {
|
|
unsigned long dword1;
|
|
Hpte_dword1 dw1;
|
|
Hpte_dword1_flags flags;
|
|
} dw1;
|
|
} HPTE;
|
|
|
|
extern HPTE * htab_address;
|
|
extern unsigned long htab_hash_mask;
|
|
|
|
static inline unsigned long hpt_hash(unsigned long vpn, int large)
|
|
{
|
|
unsigned long vsid;
|
|
unsigned long page;
|
|
|
|
if (large) {
|
|
vsid = vpn >> 4;
|
|
page = vpn & 0xf;
|
|
} else {
|
|
vsid = vpn >> 16;
|
|
page = vpn & 0xffff;
|
|
}
|
|
|
|
return (vsid & 0x7fffffffffUL) ^ page;
|
|
}
|
|
|
|
static inline void __tlbie(unsigned long va, int large)
|
|
{
|
|
/* clear top 16 bits, non SLS segment */
|
|
va &= ~(0xffffULL << 48);
|
|
|
|
if (large) {
|
|
va &= HPAGE_MASK;
|
|
asm volatile("tlbie %0,1" : : "r"(va) : "memory");
|
|
} else {
|
|
va &= PAGE_MASK;
|
|
asm volatile("tlbie %0,0" : : "r"(va) : "memory");
|
|
}
|
|
}
|
|
|
|
static inline void tlbie(unsigned long va, int large)
|
|
{
|
|
asm volatile("ptesync": : :"memory");
|
|
__tlbie(va, large);
|
|
asm volatile("eieio; tlbsync; ptesync": : :"memory");
|
|
}
|
|
|
|
static inline void __tlbiel(unsigned long va)
|
|
{
|
|
/* clear top 16 bits, non SLS segment */
|
|
va &= ~(0xffffULL << 48);
|
|
va &= PAGE_MASK;
|
|
|
|
/*
|
|
* Thanks to Alan Modra we are now able to use machine specific
|
|
* assembly instructions (like tlbiel) by using the gas -many flag.
|
|
* However we have to support older toolchains so for the moment
|
|
* we hardwire it.
|
|
*/
|
|
#if 0
|
|
asm volatile("tlbiel %0" : : "r"(va) : "memory");
|
|
#else
|
|
asm volatile(".long 0x7c000224 | (%0 << 11)" : : "r"(va) : "memory");
|
|
#endif
|
|
}
|
|
|
|
static inline void tlbiel(unsigned long va)
|
|
{
|
|
asm volatile("ptesync": : :"memory");
|
|
__tlbiel(va);
|
|
asm volatile("ptesync": : :"memory");
|
|
}
|
|
|
|
/*
|
|
* Handle a fault by adding an HPTE. If the address can't be determined
|
|
* to be valid via Linux page tables, return 1. If handled return 0
|
|
*/
|
|
extern int __hash_page(unsigned long ea, unsigned long access,
|
|
unsigned long vsid, pte_t *ptep, unsigned long trap,
|
|
int local);
|
|
|
|
extern void htab_finish_init(void);
|
|
|
|
extern void hpte_init_native(void);
|
|
extern void hpte_init_lpar(void);
|
|
extern void hpte_init_iSeries(void);
|
|
|
|
extern long pSeries_lpar_hpte_insert(unsigned long hpte_group,
|
|
unsigned long va, unsigned long prpn,
|
|
int secondary, unsigned long hpteflags,
|
|
int bolted, int large);
|
|
extern long native_hpte_insert(unsigned long hpte_group, unsigned long va,
|
|
unsigned long prpn, int secondary,
|
|
unsigned long hpteflags, int bolted, int large);
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
/*
|
|
* VSID allocation
|
|
*
|
|
* We first generate a 36-bit "proto-VSID". For kernel addresses this
|
|
* is equal to the ESID, for user addresses it is:
|
|
* (context << 15) | (esid & 0x7fff)
|
|
*
|
|
* The two forms are distinguishable because the top bit is 0 for user
|
|
* addresses, whereas the top two bits are 1 for kernel addresses.
|
|
* Proto-VSIDs with the top two bits equal to 0b10 are reserved for
|
|
* now.
|
|
*
|
|
* The proto-VSIDs are then scrambled into real VSIDs with the
|
|
* multiplicative hash:
|
|
*
|
|
* VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS
|
|
* where VSID_MULTIPLIER = 268435399 = 0xFFFFFC7
|
|
* VSID_MODULUS = 2^36-1 = 0xFFFFFFFFF
|
|
*
|
|
* This scramble is only well defined for proto-VSIDs below
|
|
* 0xFFFFFFFFF, so both proto-VSID and actual VSID 0xFFFFFFFFF are
|
|
* reserved. VSID_MULTIPLIER is prime, so in particular it is
|
|
* co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
|
|
* Because the modulus is 2^n-1 we can compute it efficiently without
|
|
* a divide or extra multiply (see below).
|
|
*
|
|
* This scheme has several advantages over older methods:
|
|
*
|
|
* - We have VSIDs allocated for every kernel address
|
|
* (i.e. everything above 0xC000000000000000), except the very top
|
|
* segment, which simplifies several things.
|
|
*
|
|
* - We allow for 15 significant bits of ESID and 20 bits of
|
|
* context for user addresses. i.e. 8T (43 bits) of address space for
|
|
* up to 1M contexts (although the page table structure and context
|
|
* allocation will need changes to take advantage of this).
|
|
*
|
|
* - The scramble function gives robust scattering in the hash
|
|
* table (at least based on some initial results). The previous
|
|
* method was more susceptible to pathological cases giving excessive
|
|
* hash collisions.
|
|
*/
|
|
/*
|
|
* WARNING - If you change these you must make sure the asm
|
|
* implementations in slb_allocate (slb_low.S), do_stab_bolted
|
|
* (head.S) and ASM_VSID_SCRAMBLE (below) are changed accordingly.
|
|
*
|
|
* You'll also need to change the precomputed VSID values in head.S
|
|
* which are used by the iSeries firmware.
|
|
*/
|
|
|
|
#define VSID_MULTIPLIER ASM_CONST(200730139) /* 28-bit prime */
|
|
#define VSID_BITS 36
|
|
#define VSID_MODULUS ((1UL<<VSID_BITS)-1)
|
|
|
|
#define CONTEXT_BITS 20
|
|
#define USER_ESID_BITS 15
|
|
|
|
/*
|
|
* This macro generates asm code to compute the VSID scramble
|
|
* function. Used in slb_allocate() and do_stab_bolted. The function
|
|
* computed is: (protovsid*VSID_MULTIPLIER) % VSID_MODULUS
|
|
*
|
|
* rt = register continaing the proto-VSID and into which the
|
|
* VSID will be stored
|
|
* rx = scratch register (clobbered)
|
|
*
|
|
* - rt and rx must be different registers
|
|
* - The answer will end up in the low 36 bits of rt. The higher
|
|
* bits may contain other garbage, so you may need to mask the
|
|
* result.
|
|
*/
|
|
#define ASM_VSID_SCRAMBLE(rt, rx) \
|
|
lis rx,VSID_MULTIPLIER@h; \
|
|
ori rx,rx,VSID_MULTIPLIER@l; \
|
|
mulld rt,rt,rx; /* rt = rt * MULTIPLIER */ \
|
|
\
|
|
srdi rx,rt,VSID_BITS; \
|
|
clrldi rt,rt,(64-VSID_BITS); \
|
|
add rt,rt,rx; /* add high and low bits */ \
|
|
/* Now, r3 == VSID (mod 2^36-1), and lies between 0 and \
|
|
* 2^36-1+2^28-1. That in particular means that if r3 >= \
|
|
* 2^36-1, then r3+1 has the 2^36 bit set. So, if r3+1 has \
|
|
* the bit clear, r3 already has the answer we want, if it \
|
|
* doesn't, the answer is the low 36 bits of r3+1. So in all \
|
|
* cases the answer is the low 36 bits of (r3 + ((r3+1) >> 36))*/\
|
|
addi rx,rt,1; \
|
|
srdi rx,rx,VSID_BITS; /* extract 2^36 bit */ \
|
|
add rt,rt,rx
|
|
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
typedef unsigned long mm_context_id_t;
|
|
|
|
typedef struct {
|
|
mm_context_id_t id;
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
pgd_t *huge_pgdir;
|
|
u16 htlb_segs; /* bitmask */
|
|
#endif
|
|
} mm_context_t;
|
|
|
|
|
|
static inline unsigned long vsid_scramble(unsigned long protovsid)
|
|
{
|
|
#if 0
|
|
/* The code below is equivalent to this function for arguments
|
|
* < 2^VSID_BITS, which is all this should ever be called
|
|
* with. However gcc is not clever enough to compute the
|
|
* modulus (2^n-1) without a second multiply. */
|
|
return ((protovsid * VSID_MULTIPLIER) % VSID_MODULUS);
|
|
#else /* 1 */
|
|
unsigned long x;
|
|
|
|
x = protovsid * VSID_MULTIPLIER;
|
|
x = (x >> VSID_BITS) + (x & VSID_MODULUS);
|
|
return (x + ((x+1) >> VSID_BITS)) & VSID_MODULUS;
|
|
#endif /* 1 */
|
|
}
|
|
|
|
/* This is only valid for addresses >= KERNELBASE */
|
|
static inline unsigned long get_kernel_vsid(unsigned long ea)
|
|
{
|
|
return vsid_scramble(ea >> SID_SHIFT);
|
|
}
|
|
|
|
/* This is only valid for user addresses (which are below 2^41) */
|
|
static inline unsigned long get_vsid(unsigned long context, unsigned long ea)
|
|
{
|
|
return vsid_scramble((context << USER_ESID_BITS)
|
|
| (ea >> SID_SHIFT));
|
|
}
|
|
|
|
#endif /* __ASSEMBLY */
|
|
|
|
#endif /* _PPC64_MMU_H_ */
|