RFC: powerpc: Start splitting up mmu.h by MMU type

RFC: powerpc: Start splitting up mmu.h by MMU type

[David Gibson]

This patch makes a start to sorting out the tangled mess of MMU
related header files in asm-powerpc, and weaning arch/powerpc off the
remaining asm-ppc headers it uses.

Specifically it splits the ppc64 specific (or more strictly, the
64-bit hash table specific) parts of asm-powerpc/mmu.h into its own
file, asm-powerpc/mmu-hash64/mmu.h.  Similarly, PowerPC 44x
definitions are taken from asm-ppc/mmu.h, trimmed down for use in
arch/powerpc and place in their own file, asm-powerpc/mmu-44x/mmu.h.

mmu.h definitions for other 32-bit MMU types remain in asm-ppc/mmu.h
for now, but should be likewise split into their own files.

Index: working-2.6/include/asm-powerpc/mmu.h
===================================================================
--- working-2.6.orig/include/asm-powerpc/mmu.h	2007-02-09 09:57:55.000000000 +1100
+++ working-2.6/include/asm-powerpc/mmu.h	2007-04-19 15:06:52.000000000 +1000
@@ -2,407 +2,17 @@
 #define _ASM_POWERPC_MMU_H_
 #ifdef __KERNEL__
 
-#ifndef CONFIG_PPC64
-#include <asm-ppc/mmu.h>
+#if defined(CONFIG_PPC64)
+/* 64-bit classic hash table MMU */
+#  include <asm/mmu-hash64/mmu.h>
+#elif defined(CONFIG_44x)
+/* 44x-style software loaded TLB */
+#  include <asm/mmu-44x/mmu.h>
 #else
-
-/*
- * 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.
- */
-
-#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_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;
+/* Other 32-bit.  FIXME: split up the other 32-bit MMU types, and
+ * revise for arch/powerpc */
+#  include <asm-ppc/mmu.h>
 #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 /* CONFIG_PPC64 */
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_MMU_H_ */
Index: working-2.6/include/asm-powerpc/mmu-44x/mmu.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ working-2.6/include/asm-powerpc/mmu-44x/mmu.h	2007-04-19 15:27:16.000000000 +1000
@@ -0,0 +1,75 @@
+#ifndef _ASM_POWERPC_MMU_44X_MMU_H_
+#define _ASM_POWERPC_MMU_44X_MMU_H_
+
+/*
+ * PPC440 support
+ */
+#define PPC44x_MMUCR_TID	0x000000ff
+#define PPC44x_MMUCR_STS	0x00010000
+
+#define	PPC44x_TLB_PAGEID	0
+#define	PPC44x_TLB_XLAT		1
+#define	PPC44x_TLB_ATTRIB	2
+
+/* Page identification fields */
+#define PPC44x_TLB_EPN_MASK	0xfffffc00      /* Effective Page Number */
+#define	PPC44x_TLB_VALID	0x00000200      /* Valid flag */
+#define PPC44x_TLB_TS		0x00000100	/* Translation address space */
+#define PPC44x_TLB_1K		0x00000000	/* Page sizes */
+#define PPC44x_TLB_4K		0x00000010
+#define PPC44x_TLB_16K		0x00000020
+#define PPC44x_TLB_64K		0x00000030
+#define PPC44x_TLB_256K		0x00000040
+#define PPC44x_TLB_1M		0x00000050
+#define PPC44x_TLB_16M		0x00000070
+#define	PPC44x_TLB_256M		0x00000090
+
+/* Translation fields */
+#define PPC44x_TLB_RPN_MASK	0xfffffc00      /* Real Page Number */
+#define	PPC44x_TLB_ERPN_MASK	0x0000000f
+
+/* Storage attribute and access control fields */
+#define PPC44x_TLB_ATTR_MASK	0x0000ff80
+#define PPC44x_TLB_U0		0x00008000      /* User 0 */
+#define PPC44x_TLB_U1		0x00004000      /* User 1 */
+#define PPC44x_TLB_U2		0x00002000      /* User 2 */
+#define PPC44x_TLB_U3		0x00001000      /* User 3 */
+#define PPC44x_TLB_W		0x00000800      /* Caching is write-through */
+#define PPC44x_TLB_I		0x00000400      /* Caching is inhibited */
+#define PPC44x_TLB_M		0x00000200      /* Memory is coherent */
+#define PPC44x_TLB_G		0x00000100      /* Memory is guarded */
+#define PPC44x_TLB_E		0x00000080      /* Memory is guarded */
+
+#define PPC44x_TLB_PERM_MASK	0x0000003f
+#define PPC44x_TLB_UX		0x00000020      /* User execution */
+#define PPC44x_TLB_UW		0x00000010      /* User write */
+#define PPC44x_TLB_UR		0x00000008      /* User read */
+#define PPC44x_TLB_SX		0x00000004      /* Super execution */
+#define PPC44x_TLB_SW		0x00000002      /* Super write */
+#define PPC44x_TLB_SR		0x00000001      /* Super read */
+
+/* Number of TLB entries */
+#define PPC44x_TLB_SIZE		64
+
+#ifndef __ASSEMBLY__
+
+typedef unsigned long long phys_addr_t;
+
+extern phys_addr_t fixup_bigphys_addr(phys_addr_t, phys_addr_t);
+#define PHYS_FMT	"%16Lx"
+
+typedef struct {
+	unsigned long id;
+	unsigned long vdso_base;
+} mm_context_t;
+
+#endif /* !__ASSEMBLY__ */
+
+/* TLB entry offset/size used for pinning kernel lowmem */
+#define PPC44x_PIN_SHIFT	28
+#define PPC_PIN_SIZE		(1 << PPC44x_PIN_SHIFT)
+
+#define PPC44x_EARLY_TLBS	1
+
+#endif /* _ASM_POWERPC_MMU_44X_MMU_H_ */
+
Index: working-2.6/include/asm-powerpc/mmu-hash64/mmu.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ working-2.6/include/asm-powerpc/mmu-hash64/mmu.h	2007-04-19 15:19:17.000000000 +1000
@@ -0,0 +1,399 @@
+#ifndef _ASM_POWERPC_MMU_HASH64_MMU_H_
+#define _ASM_POWERPC_MMU_HASH64_MMU_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_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_MMU_H_ */

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: RFC: powerpc: Start splitting up mmu.h by MMU type

[Kumar Gala]

On Apr 19, 2007, at 1:54 AM, David Gibson wrote:

> This patch makes a start to sorting out the tangled mess of MMU
> related header files in asm-powerpc, and weaning arch/powerpc off the
> remaining asm-ppc headers it uses.
>
> Specifically it splits the ppc64 specific (or more strictly, the
> 64-bit hash table specific) parts of asm-powerpc/mmu.h into its own
> file, asm-powerpc/mmu-hash64/mmu.h.  Similarly, PowerPC 44x
> definitions are taken from asm-ppc/mmu.h, trimmed down for use in
> arch/powerpc and place in their own file, asm-powerpc/mmu-44x/mmu.h.
>
> mmu.h definitions for other 32-bit MMU types remain in asm-ppc/mmu.h
> for now, but should be likewise split into their own files.

I asked this before, but why the need for a separate directory per  
mmu type?  why not just include/asm-powerpc/mmu-44x.h?

- k

Re: RFC: powerpc: Start splitting up mmu.h by MMU type

[David Gibson]

On Thu, Apr 19, 2007 at 07:11:07AM -0500, Kumar Gala wrote:
> 
> On Apr 19, 2007, at 1:54 AM, David Gibson wrote:
> 
> > This patch makes a start to sorting out the tangled mess of MMU
> > related header files in asm-powerpc, and weaning arch/powerpc off the
> > remaining asm-ppc headers it uses.
> >
> > Specifically it splits the ppc64 specific (or more strictly, the
> > 64-bit hash table specific) parts of asm-powerpc/mmu.h into its own
> > file, asm-powerpc/mmu-hash64/mmu.h.  Similarly, PowerPC 44x
> > definitions are taken from asm-ppc/mmu.h, trimmed down for use in
> > arch/powerpc and place in their own file, asm-powerpc/mmu-44x/mmu.h.
> >
> > mmu.h definitions for other 32-bit MMU types remain in asm-ppc/mmu.h
> > for now, but should be likewise split into their own files.
> 
> I asked this before, but why the need for a separate directory per  
> mmu type?  why not just include/asm-powerpc/mmu-44x.h?

Because I have further patches in the works that add MMU specific
versions of tlbflush.h, pgtable.h and so forth to the same
directories.

I'm not wedded to the idea, but it seemed like a reasonable way to
organize things.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

Re: RFC: powerpc: Start splitting up mmu.h by MMU type

[Kumar Gala]

On Apr 19, 2007, at 7:56 PM, David Gibson wrote:

> On Thu, Apr 19, 2007 at 07:11:07AM -0500, Kumar Gala wrote:
>>
>> On Apr 19, 2007, at 1:54 AM, David Gibson wrote:
>>
>>> This patch makes a start to sorting out the tangled mess of MMU
>>> related header files in asm-powerpc, and weaning arch/powerpc off  
>>> the
>>> remaining asm-ppc headers it uses.
>>>
>>> Specifically it splits the ppc64 specific (or more strictly, the
>>> 64-bit hash table specific) parts of asm-powerpc/mmu.h into its own
>>> file, asm-powerpc/mmu-hash64/mmu.h.  Similarly, PowerPC 44x
>>> definitions are taken from asm-ppc/mmu.h, trimmed down for use in
>>> arch/powerpc and place in their own file, asm-powerpc/mmu-44x/mmu.h.
>>>
>>> mmu.h definitions for other 32-bit MMU types remain in asm-ppc/mmu.h
>>> for now, but should be likewise split into their own files.
>>
>> I asked this before, but why the need for a separate directory per
>> mmu type?  why not just include/asm-powerpc/mmu-44x.h?
>
> Because I have further patches in the works that add MMU specific
> versions of tlbflush.h, pgtable.h and so forth to the same
> directories.

Well I agree pgtable.h getting split wouldn't be a bad idea.  But  
tlbflush.h is only 146 lines, splitting it doesn't seem worth the  
trouble.  So having a mmu-44x, mmu-hash32, mmu-hash64, mmu-8xx, mmu- 
fsl_booke, mmu-40x for just two files seems a bit much.

> I'm not wedded to the idea, but it seemed like a reasonable way to
> organize things.

- k

Re: RFC: powerpc: Start splitting up mmu.h by MMU type

[Paul Mackerras]

David Gibson writes:

> This patch makes a start to sorting out the tangled mess of MMU
> related header files in asm-powerpc, and weaning arch/powerpc off the
> remaining asm-ppc headers it uses.

Good...

> Specifically it splits the ppc64 specific (or more strictly, the
> 64-bit hash table specific) parts of asm-powerpc/mmu.h into its own
> file, asm-powerpc/mmu-hash64/mmu.h.  Similarly, PowerPC 44x
> definitions are taken from asm-ppc/mmu.h, trimmed down for use in
> arch/powerpc and place in their own file, asm-powerpc/mmu-44x/mmu.h.

Why do we want to create a directory per mmu type?  What other files
would go in there?

Paul.

Re: RFC: powerpc: Start splitting up mmu.h by MMU type

[Benjamin Herrenschmidt]

> > Specifically it splits the ppc64 specific (or more strictly, the
> > 64-bit hash table specific) parts of asm-powerpc/mmu.h into its own
> > file, asm-powerpc/mmu-hash64/mmu.h.  Similarly, PowerPC 44x
> > definitions are taken from asm-ppc/mmu.h, trimmed down for use in
> > arch/powerpc and place in their own file, asm-powerpc/mmu-44x/mmu.h.
> 
> Why do we want to create a directory per mmu type?  What other files
> would go in there?

Especially if we're ever going to get a different MMU type on 64 bits, I
would really like to try to be able to build a kernel supporting both
(if realistic).

Ben.