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Diffstat (limited to 'arch/powerpc/mm/slb_low.S')
| -rw-r--r-- | arch/powerpc/mm/slb_low.S | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S new file mode 100644 index 00000000000..a3a03da503b --- /dev/null +++ b/arch/powerpc/mm/slb_low.S @@ -0,0 +1,151 @@ +/* + * arch/ppc64/mm/slb_low.S + * + * Low-level SLB routines + * + * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM + * + * Based on earlier C version: + * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com + * Copyright (c) 2001 Dave Engebretsen + * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM + * + * 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 <linux/config.h> +#include <asm/processor.h> +#include <asm/page.h> +#include <asm/mmu.h> +#include <asm/ppc_asm.h> +#include <asm/asm-offsets.h> +#include <asm/cputable.h> + +/* void slb_allocate(unsigned long ea); + * + * Create an SLB entry for the given EA (user or kernel). + * r3 = faulting address, r13 = PACA + * r9, r10, r11 are clobbered by this function + * No other registers are examined or changed. + */ +_GLOBAL(slb_allocate) + /* + * First find a slot, round robin. Previously we tried to find + * a free slot first but that took too long. Unfortunately we + * dont have any LRU information to help us choose a slot. + */ +#ifdef CONFIG_PPC_ISERIES + /* + * On iSeries, the "bolted" stack segment can be cast out on + * shared processor switch so we need to check for a miss on + * it and restore it to the right slot. + */ + ld r9,PACAKSAVE(r13) + clrrdi r9,r9,28 + clrrdi r11,r3,28 + li r10,SLB_NUM_BOLTED-1 /* Stack goes in last bolted slot */ + cmpld r9,r11 + beq 3f +#endif /* CONFIG_PPC_ISERIES */ + + ld r10,PACASTABRR(r13) + addi r10,r10,1 + /* use a cpu feature mask if we ever change our slb size */ + cmpldi r10,SLB_NUM_ENTRIES + + blt+ 4f + li r10,SLB_NUM_BOLTED + +4: + std r10,PACASTABRR(r13) +3: + /* r3 = faulting address, r10 = entry */ + + srdi r9,r3,60 /* get region */ + srdi r3,r3,28 /* get esid */ + cmpldi cr7,r9,0xc /* cmp KERNELBASE for later use */ + + rldimi r10,r3,28,0 /* r10= ESID<<28 | entry */ + oris r10,r10,SLB_ESID_V@h /* r10 |= SLB_ESID_V */ + + /* r3 = esid, r10 = esid_data, cr7 = <>KERNELBASE */ + + blt cr7,0f /* user or kernel? */ + + /* kernel address: proto-VSID = ESID */ + /* WARNING - MAGIC: we don't use the VSID 0xfffffffff, but + * this code will generate the protoVSID 0xfffffffff for the + * top segment. That's ok, the scramble below will translate + * it to VSID 0, which is reserved as a bad VSID - one which + * will never have any pages in it. */ + li r11,SLB_VSID_KERNEL +BEGIN_FTR_SECTION + bne cr7,9f + li r11,(SLB_VSID_KERNEL|SLB_VSID_L) +END_FTR_SECTION_IFSET(CPU_FTR_16M_PAGE) + b 9f + +0: /* user address: proto-VSID = context<<15 | ESID */ + srdi. r9,r3,USER_ESID_BITS + bne- 8f /* invalid ea bits set */ + +#ifdef CONFIG_HUGETLB_PAGE +BEGIN_FTR_SECTION + lhz r9,PACAHIGHHTLBAREAS(r13) + srdi r11,r3,(HTLB_AREA_SHIFT-SID_SHIFT) + srd r9,r9,r11 + lhz r11,PACALOWHTLBAREAS(r13) + srd r11,r11,r3 + or r9,r9,r11 +END_FTR_SECTION_IFSET(CPU_FTR_16M_PAGE) +#endif /* CONFIG_HUGETLB_PAGE */ + + li r11,SLB_VSID_USER + +#ifdef CONFIG_HUGETLB_PAGE +BEGIN_FTR_SECTION + rldimi r11,r9,8,55 /* shift masked bit into SLB_VSID_L */ +END_FTR_SECTION_IFSET(CPU_FTR_16M_PAGE) +#endif /* CONFIG_HUGETLB_PAGE */ + + ld r9,PACACONTEXTID(r13) + rldimi r3,r9,USER_ESID_BITS,0 + +9: /* r3 = protovsid, r11 = flags, r10 = esid_data, cr7 = <>KERNELBASE */ + ASM_VSID_SCRAMBLE(r3,r9) + + rldimi r11,r3,SLB_VSID_SHIFT,16 /* combine VSID and flags */ + + /* + * No need for an isync before or after this slbmte. The exception + * we enter with and the rfid we exit with are context synchronizing. + */ + slbmte r11,r10 + + bgelr cr7 /* we're done for kernel addresses */ + + /* Update the slb cache */ + lhz r3,PACASLBCACHEPTR(r13) /* offset = paca->slb_cache_ptr */ + cmpldi r3,SLB_CACHE_ENTRIES + bge 1f + + /* still room in the slb cache */ + sldi r11,r3,1 /* r11 = offset * sizeof(u16) */ + rldicl r10,r10,36,28 /* get low 16 bits of the ESID */ + add r11,r11,r13 /* r11 = (u16 *)paca + offset */ + sth r10,PACASLBCACHE(r11) /* paca->slb_cache[offset] = esid */ + addi r3,r3,1 /* offset++ */ + b 2f +1: /* offset >= SLB_CACHE_ENTRIES */ + li r3,SLB_CACHE_ENTRIES+1 +2: + sth r3,PACASLBCACHEPTR(r13) /* paca->slb_cache_ptr = offset */ + blr + +8: /* invalid EA */ + li r3,0 /* BAD_VSID */ + li r11,SLB_VSID_USER /* flags don't much matter */ + b 9b |