powerpc: Prepare for splitting up mmu.h by MMU type
David Gibson
david at gibson.dropbear.id.au
Fri Apr 27 11:53:52 EST 2007
Currently asm-powerpc/mmu.h has definitions for the 64-bit hash based
MMU. If CONFIG_PPC64 is not set, it instead includes asm-ppc/mmu.h
which contains a particularly horrible mess of #ifdefs giving the
definitions for all the various 32-bit MMUs.
It would be nice to have the low level definitions for each MMU type
neatly in their own separate files. It would also be good to wean
arch/powerpc off dependence on the old asm-ppc/mmu.h.
This patch makes a start on such a cleanup bu moving the definitions
for the 64-bit hash MMU to their own file, asm-powerpc/mmu_hash64.h.
Definitions for the other MMUs still all come from asm-ppc/mmu.h,
however each MMU type can now be one-by-one moved over to their own
file, in the process cleaning them up stripping them of cruft no
longer necessary in arch/powerpc.
Signed-off-by: David Gibson <david at gibson.dropbear.id.au>
---
Paulus, updated to resolve conflicts with recent additions to
powerpc.git. Please apply.
Index: working-2.6/include/asm-powerpc/mmu.h
===================================================================
--- working-2.6.orig/include/asm-powerpc/mmu.h 2007-04-26 10:36:37.000000000 +1000
+++ working-2.6/include/asm-powerpc/mmu.h 2007-04-26 11:34:00.000000000 +1000
@@ -2,408 +2,14 @@
#define _ASM_POWERPC_MMU_H_
#ifdef __KERNEL__
-#ifndef CONFIG_PPC64
-#include <asm-ppc/mmu.h>
+#ifdef CONFIG_PPC64
+/* 64-bit classic hash table MMU */
+# include <asm/mmu-hash64.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_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 at h; \
- ori rx,rx,VSID_MULTIPLIER at 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;
+/* 32-bit. FIXME: split up the 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-hash64.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ working-2.6/include/asm-powerpc/mmu-hash64.h 2007-04-26 11:33:11.000000000 +1000
@@ -0,0 +1,400 @@
+#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 at h; \
+ ori rx,rx,VSID_MULTIPLIER at 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_ */
--
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
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