diff options
Diffstat (limited to 'include/asm-ppc64/mmu.h')
| -rw-r--r-- | include/asm-ppc64/mmu.h | 193 |
1 files changed, 147 insertions, 46 deletions
diff --git a/include/asm-ppc64/mmu.h b/include/asm-ppc64/mmu.h index 188987e9d9d..c78282a67d8 100644 --- a/include/asm-ppc64/mmu.h +++ b/include/asm-ppc64/mmu.h @@ -15,19 +15,10 @@ #include <linux/config.h> #include <asm/page.h> -#include <linux/stringify.h> -#ifndef __ASSEMBLY__ - -/* Time to allow for more things here */ -typedef unsigned long mm_context_id_t; -typedef struct { - mm_context_id_t id; -#ifdef CONFIG_HUGETLB_PAGE - pgd_t *huge_pgdir; - u16 htlb_segs; /* bitmask */ -#endif -} mm_context_t; +/* + * Segment table + */ #define STE_ESID_V 0x80 #define STE_ESID_KS 0x20 @@ -36,15 +27,48 @@ typedef struct { #define STE_VSID_SHIFT 12 -struct stab_entry { - unsigned long esid_data; - unsigned long vsid_data; -}; +/* Location of cpu0's segment table */ +#define STAB0_PAGE 0x9 +#define STAB0_PHYS_ADDR (STAB0_PAGE<<PAGE_SHIFT) +#define STAB0_VIRT_ADDR (KERNELBASE+STAB0_PHYS_ADDR) + +/* + * SLB + */ -/* Hardware Page Table Entry */ +#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_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) /* largepage 16M */ +#define SLB_VSID_C ASM_CONST(0x0000000000000080) /* class */ + +#define SLB_VSID_KERNEL (SLB_VSID_KP|SLB_VSID_C) +#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS) + +/* + * Hash table + */ #define HPTES_PER_GROUP 8 +/* 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__ + +/* Hardware Page Table Entry */ typedef struct { unsigned long avpn:57; /* vsid | api == avpn */ unsigned long : 2; /* Software use */ @@ -90,14 +114,6 @@ typedef struct { } dw1; } HPTE; -/* 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 */ - - extern HPTE * htab_address; extern unsigned long htab_hash_mask; @@ -174,31 +190,70 @@ extern int __hash_page(unsigned long ea, unsigned long access, extern void htab_finish_init(void); +extern void hpte_init_native(void); +extern void hpte_init_lpar(void); +extern void hpte_init_iSeries(void); + +extern long pSeries_lpar_hpte_insert(unsigned long hpte_group, + unsigned long va, unsigned long prpn, + int secondary, unsigned long hpteflags, + int bolted, int large); +extern long native_hpte_insert(unsigned long hpte_group, unsigned long va, + unsigned long prpn, int secondary, + unsigned long hpteflags, int bolted, int large); + #endif /* __ASSEMBLY__ */ /* - * Location of cpu0's segment table + * 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 STAB0_PAGE 0x9 -#define STAB0_PHYS_ADDR (STAB0_PAGE<<PAGE_SHIFT) -#define STAB0_VIRT_ADDR (KERNELBASE+STAB0_PHYS_ADDR) - -#define SLB_NUM_BOLTED 3 -#define SLB_CACHE_ENTRIES 8 - -/* Bits in the SLB ESID word */ -#define SLB_ESID_V 0x0000000008000000 /* entry is valid */ - -/* Bits in the SLB VSID word */ -#define SLB_VSID_SHIFT 12 -#define SLB_VSID_KS 0x0000000000000800 -#define SLB_VSID_KP 0x0000000000000400 -#define SLB_VSID_N 0x0000000000000200 /* no-execute */ -#define SLB_VSID_L 0x0000000000000100 /* largepage (4M) */ -#define SLB_VSID_C 0x0000000000000080 /* class */ - -#define SLB_VSID_KERNEL (SLB_VSID_KP|SLB_VSID_C) -#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS) #define VSID_MULTIPLIER ASM_CONST(200730139) /* 28-bit prime */ #define VSID_BITS 36 @@ -239,4 +294,50 @@ extern void htab_finish_init(void); 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; +#ifdef CONFIG_HUGETLB_PAGE + pgd_t *huge_pgdir; + u16 htlb_segs; /* bitmask */ +#endif +} 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)); +} + +#endif /* __ASSEMBLY */ + #endif /* _PPC64_MMU_H_ */ |