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Diffstat (limited to 'arch/powerpc/include/asm/book3s/64/mmu-hash.h')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/mmu-hash.h | 616 |
1 files changed, 616 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h new file mode 100644 index 000000000000..0cea4807e26f --- /dev/null +++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h @@ -0,0 +1,616 @@ +#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> +#include <asm/bug.h> + +/* + * This is necessary to get the definition of PGTABLE_RANGE which we + * need for various slices related matters. Note that this isn't the + * complete pgtable.h but only a portion of it. + */ +#include <asm/book3s/64/pgtable.h> +#include <asm/bug.h> +#include <asm/processor.h> + +/* + * 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) */ +#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 */ +#define PP_RXXX (HPTE_R_PP0 | 2) /* Supervisor read, user none */ + +/* Fields for tlbiel instruction in architecture 2.06 */ +#define TLBIEL_INVAL_SEL_MASK 0xc00 /* invalidation selector */ +#define TLBIEL_INVAL_PAGE 0x000 /* invalidate a single page */ +#define TLBIEL_INVAL_SET_LPID 0x800 /* invalidate a set for current LPID */ +#define TLBIEL_INVAL_SET 0xc00 /* invalidate a set for all LPIDs */ +#define TLBIEL_INVAL_SET_MASK 0xfff000 /* set number to inval. */ +#define TLBIEL_INVAL_SET_SHIFT 12 + +#define POWER7_TLB_SETS 128 /* # sets in POWER7 TLB */ +#define POWER8_TLB_SETS 512 /* # sets in POWER8 TLB */ +#define POWER9_TLB_SETS_HASH 256 /* # sets in POWER9 TLB Hash mode */ + +#ifndef __ASSEMBLY__ + +struct hash_pte { + __be64 v; + __be64 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 */ + int penc[MMU_PAGE_COUNT]; /* 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) */ +}; +extern struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT]; + +static inline int shift_to_mmu_psize(unsigned int shift) +{ + int psize; + + for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) + if (mmu_psize_defs[psize].shift == shift) + return psize; + return -1; +} + +static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize) +{ + if (mmu_psize_defs[mmu_psize].shift) + return mmu_psize_defs[mmu_psize].shift; + BUG(); +} + +#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 + +/* + * 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 + +/* + * HPTE Large Page (LP) details + */ +#define LP_SHIFT 12 +#define LP_BITS 8 +#define LP_MASK(i) ((0xFF >> (i)) << LP_SHIFT) + +#ifndef __ASSEMBLY__ + +static inline int slb_vsid_shift(int ssize) +{ + if (ssize == MMU_SEGSIZE_256M) + return SLB_VSID_SHIFT; + return SLB_VSID_SHIFT_1T; +} + +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 + */ +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 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 + * using the base page size and actual page size. + */ +static inline unsigned long hpte_encode_v(unsigned long vpn, int base_psize, + int actual_psize, int ssize) +{ + unsigned long v; + v = hpte_encode_avpn(vpn, base_psize, ssize); + if (actual_psize != MMU_PAGE_4K) + v |= HPTE_V_LARGE; + 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 base_psize, + int actual_psize) +{ + /* A 4K page needs no special encoding */ + if (actual_psize == MMU_PAGE_4K) + return pa & HPTE_R_RPN; + else { + unsigned int penc = mmu_psize_defs[base_psize].penc[actual_psize]; + unsigned int shift = mmu_psize_defs[actual_psize].shift; + return (pa & ~((1ul << shift) - 1)) | (penc << LP_SHIFT); + } +} + +/* + * Build a VPN_SHIFT bit shifted va given VSID, EA and segment size. + */ +static inline unsigned long hpt_vpn(unsigned long ea, + unsigned long vsid, int ssize) +{ + 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 vpn, + unsigned int shift, int ssize) +{ + int mask; + unsigned long hash, vsid; + + /* VPN_SHIFT can be atmost 12 */ + if (ssize == MMU_SEGSIZE_256M) { + mask = (1ul << (SID_SHIFT - VPN_SHIFT)) - 1; + hash = (vpn >> (SID_SHIFT - VPN_SHIFT)) ^ + ((vpn & mask) >> (shift - VPN_SHIFT)); + } else { + 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; +} + +#define HPTE_LOCAL_UPDATE 0x1 +#define HPTE_NOHPTE_UPDATE 0x2 + +extern int __hash_page_4K(unsigned long ea, unsigned long access, + unsigned long vsid, pte_t *ptep, unsigned long trap, + unsigned long flags, 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 long flags, int ssize); +struct mm_struct; +unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap); +extern int hash_page_mm(struct mm_struct *mm, unsigned long ea, + unsigned long access, unsigned long trap, + unsigned long flags); +extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap, + unsigned long dsisr); +int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid, + pte_t *ptep, unsigned long trap, unsigned long flags, + int ssize, unsigned int shift, unsigned int mmu_psize); +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +extern int __hash_page_thp(unsigned long ea, unsigned long access, + unsigned long vsid, pmd_t *pmdp, unsigned long trap, + unsigned long flags, int ssize, unsigned int psize); +#else +static inline int __hash_page_thp(unsigned long ea, unsigned long access, + unsigned long vsid, pmd_t *pmdp, + unsigned long trap, unsigned long flags, + int ssize, unsigned int psize) +{ + BUG(); + return -1; +} +#endif +extern void hash_failure_debug(unsigned long ea, unsigned long access, + unsigned long vsid, unsigned long trap, + int ssize, int psize, int lpsize, + unsigned long pte); +extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend, + unsigned long pstart, unsigned long prot, + int psize, int ssize); +int htab_remove_mapping(unsigned long vstart, unsigned long vend, + 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_beat(void); +extern void hpte_init_beat_v3(void); + +extern void slb_initialize(void); +extern void slb_flush_and_rebolt(void); + +extern void slb_vmalloc_update(void); +extern void slb_set_size(u16 size); +#endif /* __ASSEMBLY__ */ + +/* + * VSID allocation (256MB segment) + * + * We first generate a 37-bit "proto-VSID". Proto-VSIDs are generated + * from mmu context id and effective segment id of the address. + * + * For user processes max context id is limited to ((1ul << 19) - 5) + * for kernel space, we use the top 4 context ids to map address as below + * NOTE: each context only support 64TB now. + * 0x7fffc - [ 0xc000000000000000 - 0xc0003fffffffffff ] + * 0x7fffd - [ 0xd000000000000000 - 0xd0003fffffffffff ] + * 0x7fffe - [ 0xe000000000000000 - 0xe0003fffffffffff ] + * 0x7ffff - [ 0xf000000000000000 - 0xf0003fffffffffff ] + * + * The proto-VSIDs are then scrambled into real VSIDs with the + * multiplicative hash: + * + * VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS + * + * 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). The scramble function gives + * robust scattering in the hash table (at least based on some initial + * results). + * + * We also consider VSID 0 special. We use VSID 0 for slb entries mapping + * bad address. This enables us to consolidate bad address handling in + * hash_page. + * + * We also need to avoid the last segment of the last context, because that + * would give a protovsid of 0x1fffffffff. That will result in a VSID 0 + * because of the modulo operation in vsid scramble. But the vmemmap + * (which is what uses region 0xf) will never be close to 64TB in size + * (it's 56 bytes per page of system memory). + */ + +#define CONTEXT_BITS 19 +#define ESID_BITS 18 +#define ESID_BITS_1T 6 + +/* + * 256MB segment + * The proto-VSID space has 2^(CONTEX_BITS + ESID_BITS) - 1 segments + * available for user + kernel mapping. The top 4 contexts are used for + * kernel mapping. Each segment contains 2^28 bytes. Each + * context maps 2^46 bytes (64TB) so we can support 2^19-1 contexts + * (19 == 37 + 28 - 46). + */ +#define MAX_USER_CONTEXT ((ASM_CONST(1) << CONTEXT_BITS) - 5) + +/* + * 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 (CONTEXT_BITS + ESID_BITS) +#define VSID_MODULUS_256M ((1UL<<VSID_BITS_256M)-1) + +#define VSID_MULTIPLIER_1T ASM_CONST(12538073) /* 24-bit prime */ +#define VSID_BITS_1T (CONTEXT_BITS + ESID_BITS_1T) +#define VSID_MODULUS_1T ((1UL<<VSID_BITS_1T)-1) + + +#define USER_VSID_RANGE (1UL << (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 */ \ + /* NOTE: explanation based on VSID_BITS_##size = 36 \ + * 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 + +/* 4 bits per slice and we have one slice per 1TB */ +#define SLICE_ARRAY_SIZE (PGTABLE_RANGE >> 41) + +#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[(TASK_SIZE_USER64 >> 43)]; + 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 */ + unsigned char high_slices_psize[SLICE_ARRAY_SIZE]; +#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 */ +#ifdef CONFIG_PPC_64K_PAGES + /* for 4K PTE fragment support */ + void *pte_frag; +#endif +#ifdef CONFIG_SPAPR_TCE_IOMMU + struct list_head iommu_group_mem_list; +#endif +} 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 */ + +/* 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; +} + +static inline unsigned long get_vsid(unsigned long context, unsigned long ea, + int ssize) +{ + /* + * Bad address. We return VSID 0 for that + */ + if ((ea & ~REGION_MASK) >= PGTABLE_RANGE) + return 0; + + if (ssize == MMU_SEGSIZE_256M) + return vsid_scramble((context << ESID_BITS) + | (ea >> SID_SHIFT), 256M); + return vsid_scramble((context << ESID_BITS_1T) + | (ea >> SID_SHIFT_1T), 1T); +} + +/* + * This is only valid for addresses >= PAGE_OFFSET + * + * For kernel space, we use the top 4 context ids to map address as below + * 0x7fffc - [ 0xc000000000000000 - 0xc0003fffffffffff ] + * 0x7fffd - [ 0xd000000000000000 - 0xd0003fffffffffff ] + * 0x7fffe - [ 0xe000000000000000 - 0xe0003fffffffffff ] + * 0x7ffff - [ 0xf000000000000000 - 0xf0003fffffffffff ] + */ +static inline unsigned long get_kernel_vsid(unsigned long ea, int ssize) +{ + unsigned long context; + + /* + * kernel take the top 4 context from the available range + */ + context = (MAX_USER_CONTEXT) + ((ea >> 60) - 0xc) + 1; + return get_vsid(context, ea, ssize); +} + +unsigned htab_shift_for_mem_size(unsigned long mem_size); + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_POWERPC_MMU_HASH64_H_ */ |