[POWERPC] Prepare for splitting up mmu.h by MMU type

#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	0x6

#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

/* 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_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)

/*

 * Hash table

 */

#define HPTES_PER_GROUP 8

#define HPTE_V_AVPN_SHIFT	7

#define HPTE_V_AVPN		ASM_CONST(0xffffffffffffff80)

#define HPTE_V_AVPN_VAL(x)	(((x) & HPTE_V_AVPN) >> HPTE_V_AVPN_SHIFT)

#define HPTE_V_COMPARE(x,y)	(!(((x) ^ (y)) & HPTE_V_AVPN))

#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_RPN_SHIFT	12

#define HPTE_R_RPN		ASM_CONST(0x3ffffffffffff000)

#define HPTE_R_FLAGS		ASM_CONST(0x00000000000003ff)

#define HPTE_R_PP		ASM_CONST(0x0000000000000003)

#define HPTE_R_N		ASM_CONST(0x0000000000000004)

#define HPTE_R_C		ASM_CONST(0x0000000000000080)

#define HPTE_R_R		ASM_CONST(0x0000000000000100)

/* 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__

typedef struct {

	unsigned long v;

	unsigned long r;

} hpte_t;

extern hpte_t *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__ */

/*

 * The kernel use the constants below to index in the page sizes array.

 * The use of fixed constants for this purpose is better for performances

 * of the low level hash refill handlers.

 *

 * A non supported page size has a "shift" field set to 0

 *

 * Any new page size being implemented can get a new entry in here. Whether

 * the kernel will use it or not is a different matter though. The actual page

 * size used by hugetlbfs is not defined here and may be made variable

 */

#define MMU_PAGE_4K		0	/* 4K */

#define MMU_PAGE_64K		1	/* 64K */

#define MMU_PAGE_64K_AP		2	/* 64K Admixed (in a 4K segment) */

#define MMU_PAGE_1M		3	/* 1M */

#define MMU_PAGE_16M		4	/* 16M */

#define MMU_PAGE_16G		5	/* 16G */

#define MMU_PAGE_COUNT		6

#ifndef __ASSEMBLY__

/*

 * The current system page 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_io_psize;

/*

 * 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;

#ifdef CONFIG_HUGETLB_PAGE

/*

 * The page size index of the huge pages for use by hugetlbfs

 */

extern int mmu_huge_psize;

#endif /* CONFIG_HUGETLB_PAGE */

/*

 * 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)

{

	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;

	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;

}

/*

 * This hashes a virtual address for a 256Mb segment only for now

 */

static inline unsigned long hpt_hash(unsigned long va, unsigned int shift)

{

	return ((va >> 28) & 0x7fffffffffUL) ^ ((va & 0x0fffffffUL) >> shift);

}

extern int __hash_page_4K(unsigned long ea, unsigned long access,

			  unsigned long vsid, pte_t *ptep, unsigned long trap,

			  unsigned int local);

extern int __hash_page_64K(unsigned long ea, unsigned long access,

			   unsigned long vsid, pte_t *ptep, unsigned long trap,

			   unsigned int local);

struct mm_struct;

extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap);

extern int hash_huge_page(struct mm_struct *mm, unsigned long access,

			  unsigned long ea, unsigned long vsid, int local,

			  unsigned long trap);

extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,

			     unsigned long pstart, unsigned long mode,

			     int psize);

extern void htab_initialize(void);

extern void htab_initialize_secondary(void);

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 stabs_alloc(void);

extern void slb_initialize(void);

extern void slb_flush_and_rebolt(void);

extern void stab_initialize(unsigned long stab);

#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	19

#define USER_ESID_BITS	16

#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 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;

	u16 user_psize;			/* page size index */

	u16 sllp;			/* SLB entry page size encoding */

#ifdef CONFIG_HUGETLB_PAGE

	u16 low_htlb_areas, high_htlb_areas;

#endif

	unsigned long vdso_base;

} 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));

}

#define VSID_SCRAMBLE(pvsid)	(((pvsid) * VSID_MULTIPLIER) % VSID_MODULUS)

#define KERNEL_VSID(ea)		VSID_SCRAMBLE(GET_ESID(ea))

/* Physical address used by some IO functions */

typedef unsigned long phys_addr_t;

#endif /* __ASSEMBLY__ */

#endif /* _ASM_POWERPC_MMU_HASH64_H_ */