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Diffstat (limited to 'arch/powerpc/mm/slb_low.S')
| -rw-r--r-- | arch/powerpc/mm/slb_low.S | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S new file mode 100644 index 00000000..b9ee79ce --- /dev/null +++ b/arch/powerpc/mm/slb_low.S @@ -0,0 +1,283 @@ +/* + * 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> +#include <asm/firmware.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 or some other 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 +BEGIN_FTR_SECTION + b slb_finish_load +END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT) + b slb_finish_load_1T + +1: +#ifdef CONFIG_SPARSEMEM_VMEMMAP + /* Check virtual memmap region. To be patches at kernel boot */ + cmpldi cr0,r9,0xf + bne 1f +_GLOBAL(slb_miss_kernel_load_vmemmap) + li r11,0 + b 6f +1: +#endif /* CONFIG_SPARSEMEM_VMEMMAP */ + + /* vmalloc mapping gets the encoding from the PACA as the mapping + * can be demoted from 64K -> 4K dynamically on some machines + */ + clrldi r11,r10,48 + cmpldi r11,(VMALLOC_SIZE >> 28) - 1 + bgt 5f + lhz r11,PACAVMALLOCSLLP(r13) + b 6f +5: + /* IO mapping */ + _GLOBAL(slb_miss_kernel_load_io) + li r11,0 +6: +BEGIN_FTR_SECTION + b slb_finish_load +END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT) + b slb_finish_load_1T + +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 */ + + + /* when using slices, we extract the psize off the slice bitmaps + * and then we need to get the sllp encoding off the mmu_psize_defs + * array. + * + * XXX This is a bit inefficient especially for the normal case, + * so we should try to implement a fast path for the standard page + * size using the old sllp value so we avoid the array. We cannot + * really do dynamic patching unfortunately as processes might flip + * between 4k and 64k standard page size + */ +#ifdef CONFIG_PPC_MM_SLICES + cmpldi r10,16 + + /* Get the slice index * 4 in r11 and matching slice size mask in r9 */ + ld r9,PACALOWSLICESPSIZE(r13) + sldi r11,r10,2 + blt 5f + ld r9,PACAHIGHSLICEPSIZE(r13) + srdi r11,r10,(SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT - 2) + andi. r11,r11,0x3c + +5: /* Extract the psize and multiply to get an array offset */ + srd r9,r9,r11 + andi. r9,r9,0xf + mulli r9,r9,MMUPSIZEDEFSIZE + + /* Now get to the array and obtain the sllp + */ + ld r11,PACATOC(r13) + ld r11,mmu_psize_defs@got(r11) + add r11,r11,r9 + ld r11,MMUPSIZESLLP(r11) + ori r11,r11,SLB_VSID_USER +#else + /* paca context sllp already contains the SLB_VSID_USER bits */ + lhz r11,PACACONTEXTSLLP(r13) +#endif /* CONFIG_PPC_MM_SLICES */ + + ld r9,PACACONTEXTID(r13) +BEGIN_FTR_SECTION + cmpldi r10,0x1000 +END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT) + rldimi r10,r9,USER_ESID_BITS,0 +BEGIN_FTR_SECTION + bge slb_finish_load_1T +END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT) + 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,r9,256M) + 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. + */ + +7: ld r10,PACASTABRR(r13) + addi r10,r10,1 + /* This gets soft patched on boot. */ +_GLOBAL(slb_compare_rr_to_size) + cmpldi r10,0 + + 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 + +/* + * Finish loading of a 1T SLB entry (for the kernel linear mapping) and return. + * + * r3 = EA, r10 = proto-VSID, r11 = flags, clobbers r9 + */ +slb_finish_load_1T: + srdi r10,r10,40-28 /* get 1T ESID */ + ASM_VSID_SCRAMBLE(r10,r9,1T) + rldimi r11,r10,SLB_VSID_SHIFT_1T,16 /* combine VSID and flags */ + li r10,MMU_SEGSIZE_1T + rldimi r11,r10,SLB_VSID_SSIZE_SHIFT,0 /* insert segment size */ + + /* r3 = EA, r11 = VSID data */ + clrrdi r3,r3,SID_SHIFT_1T /* clear out non-ESID bits */ + b 7b + |