arch/powerpc/include/asm/mmu-hash64.h - LeafOS-Devices/android_kernel_samsung_exynos9820 - Gitiles

 #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>

 /*
  * 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/pgtable-ppc64.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 */

 #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;
 }

 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_mm(struct mm_struct *mm, unsigned long ea, unsigned long access, unsigned long 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);
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 extern int __hash_page_thp(unsigned long ea, unsigned long access,
 			   unsigned long vsid, pmd_t *pmdp, unsigned long trap,
 			   int local, 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, int local,
 				  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
 } 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);
 }
 #endif /* __ASSEMBLY__ */

 #endif /* _ASM_POWERPC_MMU_HASH64_H_ */
	#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>

	/*
	* 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/pgtable-ppc64.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 */

	#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;
	}

	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_mm(struct mm_struct *mm, unsigned long ea, unsigned long access, unsigned long 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);
	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	extern int __hash_page_thp(unsigned long ea, unsigned long access,
	unsigned long vsid, pmd_t *pmdp, unsigned long trap,
	int local, 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, int local,
	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
	} 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);
	}
	#endif /* __ASSEMBLY__ */

	#endif /* _ASM_POWERPC_MMU_HASH64_H_ */