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linux/arch/powerpc/include/asm/mmu-hash64.h
Anton Blanchard b206590c04 powerpc: Fix comment explaining our VSID layout 
We support 16TB of user address space and half a million contexts
so update the comment to reflect this.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-19 14:41:22 +11:00

497 lines
16 KiB
C
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#ifndef _ASM_POWERPC_MMU_HASH64_H_
#define _ASM_POWERPC_MMU_HASH64_H_
/*
* PowerPC64 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.
*/
#include <asm/asm-compat.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 0x8
#define STAB0_OFFSET (STAB0_PAGE << 12)
#define STAB0_PHYS_ADDR (STAB0_OFFSET + PHYSICAL_START)
#ifndef __ASSEMBLY__
extern char initial_stab[];
#endif /* ! __ASSEMBLY */
/*
* SLB
*/
#define SLB_NUM_BOLTED 3
#define SLB_CACHE_ENTRIES 8
#define SLB_MIN_SIZE 32
/* 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_SHIFT_1T 24
#define SLB_VSID_SSIZE_SHIFT 62
#define SLB_VSID_B ASM_CONST(0xc000000000000000)
#define SLB_VSID_B_256M ASM_CONST(0x0000000000000000)
#define SLB_VSID_B_1T ASM_CONST(0x4000000000000000)
#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)
#define SLB_VSID_C ASM_CONST(0x0000000000000080) /* class */
#define SLB_VSID_LP ASM_CONST(0x0000000000000030)
#define SLB_VSID_LP_00 ASM_CONST(0x0000000000000000)
#define SLB_VSID_LP_01 ASM_CONST(0x0000000000000010)
#define SLB_VSID_LP_10 ASM_CONST(0x0000000000000020)
#define SLB_VSID_LP_11 ASM_CONST(0x0000000000000030)
#define SLB_VSID_LLP (SLB_VSID_L|SLB_VSID_LP)
#define SLB_VSID_KERNEL (SLB_VSID_KP)
#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS|SLB_VSID_C)
#define SLBIE_C (0x08000000)
#define SLBIE_SSIZE_SHIFT 25
/*
* Hash table
*/
#define HPTES_PER_GROUP 8
#define HPTE_V_SSIZE_SHIFT 62
#define HPTE_V_AVPN_SHIFT 7
#define HPTE_V_AVPN ASM_CONST(0x3fffffffffffff80)
#define HPTE_V_AVPN_VAL(x) (((x) & HPTE_V_AVPN) >> HPTE_V_AVPN_SHIFT)
#define HPTE_V_COMPARE(x,y) (!(((x) ^ (y)) & 0xffffffffffffff80UL))
#define HPTE_V_BOLTED ASM_CONST(0x0000000000000010)
#define HPTE_V_LOCK ASM_CONST(0x0000000000000008)
#define HPTE_V_LARGE ASM_CONST(0x0000000000000004)
#define HPTE_V_SECONDARY ASM_CONST(0x0000000000000002)
#define HPTE_V_VALID ASM_CONST(0x0000000000000001)
#define HPTE_R_PP0 ASM_CONST(0x8000000000000000)
#define HPTE_R_TS ASM_CONST(0x4000000000000000)
#define HPTE_R_KEY_HI ASM_CONST(0x3000000000000000)
#define HPTE_R_RPN_SHIFT 12
#define HPTE_R_RPN ASM_CONST(0x0ffffffffffff000)
#define HPTE_R_PP ASM_CONST(0x0000000000000003)
#define HPTE_R_N ASM_CONST(0x0000000000000004)
#define HPTE_R_G ASM_CONST(0x0000000000000008)
#define HPTE_R_M ASM_CONST(0x0000000000000010)
#define HPTE_R_I ASM_CONST(0x0000000000000020)
#define HPTE_R_W ASM_CONST(0x0000000000000040)
#define HPTE_R_WIMG ASM_CONST(0x0000000000000078)
#define HPTE_R_C ASM_CONST(0x0000000000000080)
#define HPTE_R_R ASM_CONST(0x0000000000000100)
#define HPTE_R_KEY_LO ASM_CONST(0x0000000000000e00)
#define HPTE_V_1TB_SEG ASM_CONST(0x4000000000000000)
#define HPTE_V_VRMA_MASK ASM_CONST(0x4001ffffff000000)
/* 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__
struct hash_pte {
unsigned long v;
unsigned long r;
};
extern struct hash_pte *htab_address;
extern unsigned long htab_size_bytes;
extern unsigned long htab_hash_mask;
/*
* Page size definition
*
* shift : is the "PAGE_SHIFT" value for that page size
* sllp : is a bit mask with the value of SLB L || LP to be or'ed
* directly to a slbmte "vsid" value
* penc : is the HPTE encoding mask for the "LP" field:
*
*/
struct mmu_psize_def
{
unsigned int shift; /* number of bits */
unsigned int penc; /* HPTE encoding */
unsigned int tlbiel; /* tlbiel supported for that page size */
unsigned long avpnm; /* bits to mask out in AVPN in the HPTE */
unsigned long sllp; /* SLB L||LP (exact mask to use in slbmte) */
};
#endif /* __ASSEMBLY__ */
/*
* Segment sizes.
* These are the values used by hardware in the B field of
* SLB entries and the first dword of MMU hashtable entries.
* The B field is 2 bits; the values 2 and 3 are unused and reserved.
*/
#define MMU_SEGSIZE_256M 0
#define MMU_SEGSIZE_1T 1
#ifndef __ASSEMBLY__
/*
* The current system page and segment sizes
*/
extern struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
extern int mmu_linear_psize;
extern int mmu_virtual_psize;
extern int mmu_vmalloc_psize;
extern int mmu_vmemmap_psize;
extern int mmu_io_psize;
extern int mmu_kernel_ssize;
extern int mmu_highuser_ssize;
extern u16 mmu_slb_size;
extern unsigned long tce_alloc_start, tce_alloc_end;
/*
* If the processor supports 64k normal pages but not 64k cache
* inhibited pages, we have to be prepared to switch processes
* to use 4k pages when they create cache-inhibited mappings.
* If this is the case, mmu_ci_restrictions will be set to 1.
*/
extern int mmu_ci_restrictions;
/*
* 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)
{
unsigned long v;
v = (va >> 23) & ~(mmu_psize_defs[psize].avpnm);
v <<= HPTE_V_AVPN_SHIFT;
if (psize != MMU_PAGE_4K)
v |= HPTE_V_LARGE;
v |= ((unsigned long) ssize) << HPTE_V_SSIZE_SHIFT;
return v;
}
/*
* This function sets the ARPN, and LP fields of the HPTE appropriately
* for the page size. We assume the pa is already "clean" that is properly
* aligned for the requested page size
*/
static inline unsigned long hpte_encode_r(unsigned long pa, int psize)
{
unsigned long r;
/* A 4K page needs no special encoding */
if (psize == MMU_PAGE_4K)
return pa & HPTE_R_RPN;
else {
unsigned int penc = mmu_psize_defs[psize].penc;
unsigned int shift = mmu_psize_defs[psize].shift;
return (pa & ~((1ul << shift) - 1)) | (penc << 12);
}
return r;
}
/*
* Build a VA given VSID, EA and segment size
*/
static inline unsigned long hpt_va(unsigned long ea, unsigned long vsid,
int ssize)
{
if (ssize == MMU_SEGSIZE_256M)
return (vsid << 28) | (ea & 0xfffffffUL);
return (vsid << 40) | (ea & 0xffffffffffUL);
}
/*
* This hashes a virtual address
*/
static inline unsigned long hpt_hash(unsigned long va, unsigned int shift,
int ssize)
{
unsigned long hash, vsid;
if (ssize == MMU_SEGSIZE_256M) {
hash = (va >> 28) ^ ((va & 0x0fffffffUL) >> shift);
} else {
vsid = va >> 40;
hash = vsid ^ (vsid << 25) ^ ((va & 0xffffffffffUL) >> shift);
}
return hash & 0x7fffffffffUL;
}
extern int __hash_page_4K(unsigned long ea, unsigned long access,
unsigned long vsid, pte_t *ptep, unsigned long trap,
unsigned int local, int ssize, int subpage_prot);
extern int __hash_page_64K(unsigned long ea, unsigned long access,
unsigned long vsid, pte_t *ptep, unsigned long trap,
unsigned int local, int ssize);
struct mm_struct;
unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap);
extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap);
int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
pte_t *ptep, unsigned long trap, int local, int ssize,
unsigned int shift, unsigned int mmu_psize);
extern void hash_failure_debug(unsigned long ea, unsigned long access,
unsigned long vsid, unsigned long trap,
int ssize, int psize, unsigned long pte);
extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
unsigned long pstart, unsigned long prot,
int psize, int ssize);
extern void add_gpage(u64 addr, u64 page_size, unsigned long number_of_pages);
extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
extern void hpte_init_native(void);
extern void hpte_init_lpar(void);
extern void hpte_init_iSeries(void);
extern void hpte_init_beat(void);
extern void hpte_init_beat_v3(void);
extern void stabs_alloc(void);
extern void slb_initialize(void);
extern void slb_flush_and_rebolt(void);
extern void stab_initialize(unsigned long stab);
extern void slb_vmalloc_update(void);
extern void slb_set_size(u16 size);
#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 16 significant bits of ESID and 19 bits of
* context for user addresses. i.e. 16T (44 bits) of address space for
* up to half a million contexts.
*
* - 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_256M ASM_CONST(200730139) /* 28-bit prime */
#define VSID_BITS_256M 36
#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_MODULUS_1T ((1UL<<VSID_BITS_1T)-1)
#define CONTEXT_BITS 19
#define USER_ESID_BITS 16
#define USER_ESID_BITS_1T 4
#define USER_VSID_RANGE (1UL << (USER_ESID_BITS + SID_SHIFT))
/*
* 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 VSID_BITS bits of rt. The higher
* bits may contain other garbage, so you may need to mask the
* result.
*/
#define ASM_VSID_SCRAMBLE(rt, rx, size) \
lis rx,VSID_MULTIPLIER_##size@h; \
ori rx,rx,VSID_MULTIPLIER_##size@l; \
mulld rt,rt,rx; /* rt = rt * MULTIPLIER */ \
\
srdi rx,rt,VSID_BITS_##size; \
clrldi rt,rt,(64-VSID_BITS_##size); \
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_##size; /* extract 2^VSID_BITS bit */ \
add rt,rt,rx
#ifndef __ASSEMBLY__
#ifdef CONFIG_PPC_SUBPAGE_PROT
/*
* For the sub-page protection option, we extend the PGD with one of
* these. Basically we have a 3-level tree, with the top level being
* the protptrs array. To optimize speed and memory consumption when
* only addresses < 4GB are being protected, pointers to the first
* four pages of sub-page protection words are stored in the low_prot
* array.
* Each page of sub-page protection words protects 1GB (4 bytes
* protects 64k). For the 3-level tree, each page of pointers then
* protects 8TB.
*/
struct subpage_prot_table {
unsigned long maxaddr; /* only addresses < this are protected */
unsigned int **protptrs[2];
unsigned int *low_prot[4];
};
#define SBP_L1_BITS (PAGE_SHIFT - 2)
#define SBP_L2_BITS (PAGE_SHIFT - 3)
#define SBP_L1_COUNT (1 << SBP_L1_BITS)
#define SBP_L2_COUNT (1 << SBP_L2_BITS)
#define SBP_L2_SHIFT (PAGE_SHIFT + SBP_L1_BITS)
#define SBP_L3_SHIFT (SBP_L2_SHIFT + SBP_L2_BITS)
extern void subpage_prot_free(struct mm_struct *mm);
extern void subpage_prot_init_new_context(struct mm_struct *mm);
#else
static inline void subpage_prot_free(struct mm_struct *mm) {}
static inline void subpage_prot_init_new_context(struct mm_struct *mm) { }
#endif /* CONFIG_PPC_SUBPAGE_PROT */
typedef unsigned long mm_context_id_t;
struct spinlock;
typedef struct {
mm_context_id_t id;
u16 user_psize; /* page size index */
#ifdef CONFIG_PPC_MM_SLICES
u64 low_slices_psize; /* SLB page size encodings */
u64 high_slices_psize; /* 4 bits per slice for now */
#else
u16 sllp; /* SLB page size encoding */
#endif
unsigned long vdso_base;
#ifdef CONFIG_PPC_SUBPAGE_PROT
struct subpage_prot_table spt;
#endif /* CONFIG_PPC_SUBPAGE_PROT */
#ifdef CONFIG_PPC_ICSWX
struct spinlock *cop_lockp; /* guard acop and cop_pid */
unsigned long acop; /* mask of enabled coprocessor types */
unsigned int cop_pid; /* pid value used with coprocessors */
#endif /* CONFIG_PPC_ICSWX */
} mm_context_t;
#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.
*/
#define vsid_scramble(protovsid, size) \
((((protovsid) * VSID_MULTIPLIER_##size) % VSID_MODULUS_##size))
#else /* 1 */
#define vsid_scramble(protovsid, size) \
({ \
unsigned long x; \
x = (protovsid) * VSID_MULTIPLIER_##size; \
x = (x >> VSID_BITS_##size) + (x & VSID_MODULUS_##size); \
(x + ((x+1) >> VSID_BITS_##size)) & VSID_MODULUS_##size; \
})
#endif /* 1 */
/* This is only valid for addresses >= PAGE_OFFSET */
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);
}
/* Returns the segment size indicator for a user address */
static inline int user_segment_size(unsigned long addr)
{
/* Use 1T segments if possible for addresses >= 1T */
if (addr >= (1UL << SID_SHIFT_1T))
return mmu_highuser_ssize;
return MMU_SEGSIZE_256M;
}
/* This is only valid for user addresses (which are below 2^44) */
static inline unsigned long get_vsid(unsigned long context, unsigned long ea,
int ssize)
{
if (ssize == MMU_SEGSIZE_256M)
return vsid_scramble((context << USER_ESID_BITS)
| (ea >> SID_SHIFT), 256M);
return vsid_scramble((context << USER_ESID_BITS_1T)
| (ea >> SID_SHIFT_1T), 1T);
}
/*
* This is only used on legacy iSeries in lparmap.c,
* hence the 256MB segment assumption.
*/
#define VSID_SCRAMBLE(pvsid) (((pvsid) * VSID_MULTIPLIER_256M) % \
VSID_MODULUS_256M)
#define KERNEL_VSID(ea) VSID_SCRAMBLE(GET_ESID(ea))
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_MMU_HASH64_H_ */
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