/* * 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 <asm/processor.h> #include <asm/ppc_asm.h> #include <asm/asm-offsets.h> #include <asm/cputable.h> #include <asm/page.h> #include <asm/mmu.h> #include <asm/pgtable.h> /* void slb_allocate_realmode(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_realmode) /* r3 = faulting address */ srdi r9,r3,60 /* get region */ srdi r10,r3,28 /* get esid */ cmpldi cr7,r9,0xc /* cmp PAGE_OFFSET for later use */ /* r3 = address, r10 = esid, cr7 = <> PAGE_OFFSET */ 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. */ /* Check if hitting the linear mapping of the vmalloc/ioremap * kernel space */ bne cr7,1f /* Linear mapping encoding bits, the "li" instruction below will * be patched by the kernel at boot */ _GLOBAL(slb_miss_kernel_load_linear) li r11,0 b slb_finish_load 1: /* vmalloc/ioremap mapping encoding bits, the "li" instructions below * will be patched by the kernel at boot */ BEGIN_FTR_SECTION /* check whether this is in vmalloc or ioremap space */ clrldi r11,r10,48 cmpldi r11,(VMALLOC_SIZE >> 28) - 1 bgt 5f lhz r11,PACAVMALLOCSLLP(r13) b slb_finish_load 5: END_FTR_SECTION_IFCLR(CPU_FTR_CI_LARGE_PAGE) _GLOBAL(slb_miss_kernel_load_io) li r11,0 b slb_finish_load 0: /* user address: proto-VSID = context << 15 | ESID. First check * if the address is within the boundaries of the user region */ srdi. r9,r10,USER_ESID_BITS bne- 8f /* invalid ea bits set */ /* Figure out if the segment contains huge pages */ #ifdef CONFIG_HUGETLB_PAGE BEGIN_FTR_SECTION b 1f END_FTR_SECTION_IFCLR(CPU_FTR_16M_PAGE) cmpldi r10,16 lhz r9,PACALOWHTLBAREAS(r13) mr r11,r10 blt 5f lhz r9,PACAHIGHHTLBAREAS(r13) srdi r11,r10,(HTLB_AREA_SHIFT-SID_SHIFT) 5: srd r9,r9,r11 andi. r9,r9,1 beq 1f _GLOBAL(slb_miss_user_load_huge) li r11,0 b 2f 1: #endif /* CONFIG_HUGETLB_PAGE */ lhz r11,PACACONTEXTSLLP(r13) 2: ld r9,PACACONTEXTID(r13) rldimi r10,r9,USER_ESID_BITS,0 b slb_finish_load 8: /* invalid EA */ li r10,0 /* BAD_VSID */ li r11,SLB_VSID_USER /* flags don't much matter */ b slb_finish_load #ifdef __DISABLED__ /* void slb_allocate_user(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. * * It is called with translation enabled in order to be able to walk the * page tables. This is not currently used. */ _GLOBAL(slb_allocate_user) /* r3 = faulting address */ srdi r10,r3,28 /* get esid */ crset 4*cr7+lt /* set "user" flag for later */ /* check if we fit in the range covered by the pagetables*/ srdi. r9,r3,PGTABLE_EADDR_SIZE crnot 4*cr0+eq,4*cr0+eq beqlr /* now we need to get to the page tables in order to get the page * size encoding from the PMD. In the future, we'll be able to deal * with 1T segments too by getting the encoding from the PGD instead */ ld r9,PACAPGDIR(r13) cmpldi cr0,r9,0 beqlr rlwinm r11,r10,8,25,28 ldx r9,r9,r11 /* get pgd_t */ cmpldi cr0,r9,0 beqlr rlwinm r11,r10,3,17,28 ldx r9,r9,r11 /* get pmd_t */ cmpldi cr0,r9,0 beqlr /* build vsid flags */ andi. r11,r9,SLB_VSID_LLP ori r11,r11,SLB_VSID_USER /* get context to calculate proto-VSID */ ld r9,PACACONTEXTID(r13) rldimi r10,r9,USER_ESID_BITS,0 /* fall through slb_finish_load */ #endif /* __DISABLED__ */ /* * Finish loading of an SLB entry and return * * r3 = EA, r10 = proto-VSID, r11 = flags, clobbers r9, cr7 = <> PAGE_OFFSET */ slb_finish_load: ASM_VSID_SCRAMBLE(r10,r9) rldimi r11,r10,SLB_VSID_SHIFT,16 /* combine VSID and flags */ /* r3 = EA, r11 = VSID data */ /* * 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 r3,r3,28 li r10,SLB_NUM_BOLTED-1 /* Stack goes in last bolted slot */ cmpld r9,r3 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: rldimi r3,r10,0,36 /* r3= EA[0:35] | entry */ oris r10,r3,SLB_ESID_V@h /* r3 |= SLB_ESID_V */ /* r3 = ESID data, r11 = VSID data */ /* * 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 /* we're done for kernel addresses */ crclr 4*cr0+eq /* set result to "success" */ bgelr cr7 /* 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 */ crclr 4*cr0+eq /* set result to "success" */ blr