/* * Low-level SLB routines * * Copyright (C) 2004 David Gibson , 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 , 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 #include #include #include #include #include #include #include /* * 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 containing the proto-VSID and into which the * VSID will be stored * rx = scratch register (clobbered) * rf = flags * * - rt and rx must be different registers * - The answer will end up in the low VSID_BITS bits of rt. The higher * bits may contain other garbage, so you may need to mask the * result. */ #define ASM_VSID_SCRAMBLE(rt, rx, rf, size) \ lis rx,VSID_MULTIPLIER_##size@h; \ ori rx,rx,VSID_MULTIPLIER_##size@l; \ mulld rt,rt,rx; /* rt = rt * MULTIPLIER */ \ /* \ * powermac get slb fault before feature fixup, so make 65 bit part \ * the default part of feature fixup \ */ \ BEGIN_MMU_FTR_SECTION \ srdi rx,rt,VSID_BITS_65_##size; \ clrldi rt,rt,(64-VSID_BITS_65_##size); \ add rt,rt,rx; \ addi rx,rt,1; \ srdi rx,rx,VSID_BITS_65_##size; \ add rt,rt,rx; \ rldimi rf,rt,SLB_VSID_SHIFT_##size,(64 - (SLB_VSID_SHIFT_##size + VSID_BITS_65_##size)); \ MMU_FTR_SECTION_ELSE \ srdi rx,rt,VSID_BITS_##size; \ clrldi rt,rt,(64-VSID_BITS_##size); \ add rt,rt,rx; /* add high and low bits */ \ addi rx,rt,1; \ srdi rx,rx,VSID_BITS_##size; /* extract 2^VSID_BITS bit */ \ add rt,rt,rx; \ rldimi rf,rt,SLB_VSID_SHIFT_##size,(64 - (SLB_VSID_SHIFT_##size + VSID_BITS_##size)); \ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_68_BIT_VA) /* 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 * r3 is preserved. * No other registers are examined or changed. */ _GLOBAL(slb_allocate) /* * check for bad kernel/user address * (ea & ~REGION_MASK) >= PGTABLE_RANGE */ rldicr. r9,r3,4,(63 - H_PGTABLE_EADDR_SIZE - 4) bne- 8f srdi r9,r3,60 /* get region */ srdi r10,r3,SID_SHIFT /* 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? */ /* 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 */ .globl slb_miss_kernel_load_linear slb_miss_kernel_load_linear: li r11,0 /* * context = (ea >> 60) - (0xc - 1) * r9 = region id. */ subi r9,r9,KERNEL_REGION_CONTEXT_OFFSET BEGIN_FTR_SECTION b .Lslb_finish_load END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT) b .Lslb_finish_load_1T 1: #ifdef CONFIG_SPARSEMEM_VMEMMAP cmpldi cr0,r9,0xf bne 1f /* Check virtual memmap region. To be patched at kernel boot */ .globl slb_miss_kernel_load_vmemmap slb_miss_kernel_load_vmemmap: li r11,0 b 6f 1: #endif /* CONFIG_SPARSEMEM_VMEMMAP */ /* * r10 contains the ESID, which is the original faulting EA shifted * right by 28 bits. We need to compare that with (H_VMALLOC_END >> 28) * which is 0xd00038000. That can't be used as an immediate, even if we * ignored the 0xd, so we have to load it into a register, and we only * have one register free. So we must load all of (H_VMALLOC_END >> 28) * into a register and compare ESID against that. */ lis r11,(H_VMALLOC_END >> 32)@h // r11 = 0xffffffffd0000000 ori r11,r11,(H_VMALLOC_END >> 32)@l // r11 = 0xffffffffd0003800 // Rotate left 4, then mask with 0xffffffff0 rldic r11,r11,4,28 // r11 = 0xd00038000 cmpld r10,r11 // if r10 >= r11 bge 5f // goto io_mapping /* * vmalloc mapping gets the encoding from the PACA as the mapping * can be demoted from 64K -> 4K dynamically on some machines. */ lhz r11,PACAVMALLOCSLLP(r13) b 6f 5: /* IO mapping */ .globl slb_miss_kernel_load_io slb_miss_kernel_load_io: li r11,0 6: /* * context = (ea >> 60) - (0xc - 1) * r9 = region id. */ subi r9,r9,KERNEL_REGION_CONTEXT_OFFSET BEGIN_FTR_SECTION b .Lslb_finish_load END_MMU_FTR_SECTION_IFCLR(MMU_FTR_1T_SEGMENT) b .Lslb_finish_load_1T 0: /* * For userspace addresses, make sure this is region 0. */ cmpdi r9, 0 bne- 8f /* * user space make sure we are within the allowed limit */ ld r11,PACA_SLB_ADDR_LIMIT(r13) cmpld r3,r11 bge- 8f /* 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 /* r10 have esid */ cmpldi r10,16 /* below SLICE_LOW_TOP */ blt 5f /* * Handle hpsizes, * r9 is get_paca()->context.high_slices_psize[index], r11 is mask_index */ srdi r11,r10,(SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT + 1) /* index */ addi r9,r11,PACAHIGHSLICEPSIZE lbzx r9,r13,r9 /* r9 is hpsizes[r11] */ /* r11 = (r10 >> (SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT)) & 0x1 */ rldicl r11,r10,(64 - (SLICE_HIGH_SHIFT - SLICE_LOW_SHIFT)),63 b 6f 5: /* * Handle lpsizes * r9 is get_paca()->context.low_slices_psize, r11 is index */ ld r9,PACALOWSLICESPSIZE(r13) mr r11,r10 6: sldi r11,r11,2 /* index * 4 */ /* 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 bge .Lslb_finish_load_1T END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT) b .Lslb_finish_load 8: /* invalid EA - return an error indication */ crset 4*cr0+eq /* indicate failure */ blr /* * Finish loading of an SLB entry and return * * r3 = EA, r9 = context, r10 = ESID, r11 = flags, clobbers r9, cr7 = <> PAGE_OFFSET */ .Lslb_finish_load: rldimi r10,r9,ESID_BITS,0 ASM_VSID_SCRAMBLE(r10,r9,r11,256M) /* 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. */ mr r9,r3 /* slb_finish_load_1T continues here. r9=EA with non-ESID bits clear */ 7: ld r10,PACASTABRR(r13) addi r10,r10,1 /* This gets soft patched on boot. */ .globl slb_compare_rr_to_size slb_compare_rr_to_size: cmpldi r10,0 blt+ 4f li r10,SLB_NUM_BOLTED 4: std r10,PACASTABRR(r13) 3: rldimi r9,r10,0,36 /* r9 = EA[0:35] | entry */ oris r10,r9,SLB_ESID_V@h /* r10 = r9 | SLB_ESID_V */ /* r9 = 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 r9,PACASLBCACHEPTR(r13) /* offset = paca->slb_cache_ptr */ cmpldi r9,SLB_CACHE_ENTRIES bge 1f /* still room in the slb cache */ sldi r11,r9,2 /* r11 = offset * sizeof(u32) */ srdi r10,r10,28 /* get the 36 bits of the ESID */ add r11,r11,r13 /* r11 = (u32 *)paca + offset */ stw r10,PACASLBCACHE(r11) /* paca->slb_cache[offset] = esid */ addi r9,r9,1 /* offset++ */ b 2f 1: /* offset >= SLB_CACHE_ENTRIES */ li r9,SLB_CACHE_ENTRIES+1 2: sth r9,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, r9 = context, r10 = ESID(256MB), r11 = flags, clobbers r9 */ .Lslb_finish_load_1T: srdi r10,r10,(SID_SHIFT_1T - SID_SHIFT) /* get 1T ESID */ rldimi r10,r9,ESID_BITS_1T,0 ASM_VSID_SCRAMBLE(r10,r9,r11,1T) li r10,MMU_SEGSIZE_1T rldimi r11,r10,SLB_VSID_SSIZE_SHIFT,0 /* insert segment size */ /* r3 = EA, r11 = VSID data */ clrrdi r9,r3,SID_SHIFT_1T /* clear out non-ESID bits */ b 7b _ASM_NOKPROBE_SYMBOL(slb_allocate) _ASM_NOKPROBE_SYMBOL(slb_miss_kernel_load_linear) _ASM_NOKPROBE_SYMBOL(slb_miss_kernel_load_io) _ASM_NOKPROBE_SYMBOL(slb_compare_rr_to_size) #ifdef CONFIG_SPARSEMEM_VMEMMAP _ASM_NOKPROBE_SYMBOL(slb_miss_kernel_load_vmemmap) #endif