diff options
Diffstat (limited to 'kernel/arch/powerpc/mm/ppc_mmu_32.c')
| -rw-r--r-- | kernel/arch/powerpc/mm/ppc_mmu_32.c | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/mm/ppc_mmu_32.c b/kernel/arch/powerpc/mm/ppc_mmu_32.c new file mode 100644 index 000000000..6b2f3e457 --- /dev/null +++ b/kernel/arch/powerpc/mm/ppc_mmu_32.c @@ -0,0 +1,289 @@ +/* + * This file contains the routines for handling the MMU on those + * PowerPC implementations where the MMU substantially follows the + * architecture specification. This includes the 6xx, 7xx, 7xxx, + * and 8260 implementations but excludes the 8xx and 4xx. + * -- paulus + * + * Derived from arch/ppc/mm/init.c: + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) + * and Cort Dougan (PReP) (cort@cs.nmt.edu) + * Copyright (C) 1996 Paul Mackerras + * + * Derived from "arch/i386/mm/init.c" + * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds + * + * 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/kernel.h> +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/highmem.h> +#include <linux/memblock.h> + +#include <asm/prom.h> +#include <asm/mmu.h> +#include <asm/machdep.h> + +#include "mmu_decl.h" + +struct hash_pte *Hash, *Hash_end; +unsigned long Hash_size, Hash_mask; +unsigned long _SDR1; + +struct ppc_bat BATS[8][2]; /* 8 pairs of IBAT, DBAT */ + +struct batrange { /* stores address ranges mapped by BATs */ + unsigned long start; + unsigned long limit; + phys_addr_t phys; +} bat_addrs[8]; + +/* + * Return PA for this VA if it is mapped by a BAT, or 0 + */ +phys_addr_t v_mapped_by_bats(unsigned long va) +{ + int b; + for (b = 0; b < 4; ++b) + if (va >= bat_addrs[b].start && va < bat_addrs[b].limit) + return bat_addrs[b].phys + (va - bat_addrs[b].start); + return 0; +} + +/* + * Return VA for a given PA or 0 if not mapped + */ +unsigned long p_mapped_by_bats(phys_addr_t pa) +{ + int b; + for (b = 0; b < 4; ++b) + if (pa >= bat_addrs[b].phys + && pa < (bat_addrs[b].limit-bat_addrs[b].start) + +bat_addrs[b].phys) + return bat_addrs[b].start+(pa-bat_addrs[b].phys); + return 0; +} + +unsigned long __init mmu_mapin_ram(unsigned long top) +{ + unsigned long tot, bl, done; + unsigned long max_size = (256<<20); + + if (__map_without_bats) { + printk(KERN_DEBUG "RAM mapped without BATs\n"); + return 0; + } + + /* Set up BAT2 and if necessary BAT3 to cover RAM. */ + + /* Make sure we don't map a block larger than the + smallest alignment of the physical address. */ + tot = top; + for (bl = 128<<10; bl < max_size; bl <<= 1) { + if (bl * 2 > tot) + break; + } + + setbat(2, PAGE_OFFSET, 0, bl, PAGE_KERNEL_X); + done = (unsigned long)bat_addrs[2].limit - PAGE_OFFSET + 1; + if ((done < tot) && !bat_addrs[3].limit) { + /* use BAT3 to cover a bit more */ + tot -= done; + for (bl = 128<<10; bl < max_size; bl <<= 1) + if (bl * 2 > tot) + break; + setbat(3, PAGE_OFFSET+done, done, bl, PAGE_KERNEL_X); + done = (unsigned long)bat_addrs[3].limit - PAGE_OFFSET + 1; + } + + return done; +} + +/* + * Set up one of the I/D BAT (block address translation) register pairs. + * The parameters are not checked; in particular size must be a power + * of 2 between 128k and 256M. + */ +void __init setbat(int index, unsigned long virt, phys_addr_t phys, + unsigned int size, pgprot_t prot) +{ + unsigned int bl; + int wimgxpp; + struct ppc_bat *bat = BATS[index]; + unsigned long flags = pgprot_val(prot); + + if ((flags & _PAGE_NO_CACHE) || + (cpu_has_feature(CPU_FTR_NEED_COHERENT) == 0)) + flags &= ~_PAGE_COHERENT; + + bl = (size >> 17) - 1; + if (PVR_VER(mfspr(SPRN_PVR)) != 1) { + /* 603, 604, etc. */ + /* Do DBAT first */ + wimgxpp = flags & (_PAGE_WRITETHRU | _PAGE_NO_CACHE + | _PAGE_COHERENT | _PAGE_GUARDED); + wimgxpp |= (flags & _PAGE_RW)? BPP_RW: BPP_RX; + bat[1].batu = virt | (bl << 2) | 2; /* Vs=1, Vp=0 */ + bat[1].batl = BAT_PHYS_ADDR(phys) | wimgxpp; + if (flags & _PAGE_USER) + bat[1].batu |= 1; /* Vp = 1 */ + if (flags & _PAGE_GUARDED) { + /* G bit must be zero in IBATs */ + bat[0].batu = bat[0].batl = 0; + } else { + /* make IBAT same as DBAT */ + bat[0] = bat[1]; + } + } else { + /* 601 cpu */ + if (bl > BL_8M) + bl = BL_8M; + wimgxpp = flags & (_PAGE_WRITETHRU | _PAGE_NO_CACHE + | _PAGE_COHERENT); + wimgxpp |= (flags & _PAGE_RW)? + ((flags & _PAGE_USER)? PP_RWRW: PP_RWXX): PP_RXRX; + bat->batu = virt | wimgxpp | 4; /* Ks=0, Ku=1 */ + bat->batl = phys | bl | 0x40; /* V=1 */ + } + + bat_addrs[index].start = virt; + bat_addrs[index].limit = virt + ((bl + 1) << 17) - 1; + bat_addrs[index].phys = phys; +} + +/* + * Preload a translation in the hash table + */ +void hash_preload(struct mm_struct *mm, unsigned long ea, + unsigned long access, unsigned long trap) +{ + pmd_t *pmd; + + if (Hash == 0) + return; + pmd = pmd_offset(pud_offset(pgd_offset(mm, ea), ea), ea); + if (!pmd_none(*pmd)) + add_hash_page(mm->context.id, ea, pmd_val(*pmd)); +} + +/* + * Initialize the hash table and patch the instructions in hashtable.S. + */ +void __init MMU_init_hw(void) +{ + unsigned int hmask, mb, mb2; + unsigned int n_hpteg, lg_n_hpteg; + + extern unsigned int hash_page_patch_A[]; + extern unsigned int hash_page_patch_B[], hash_page_patch_C[]; + extern unsigned int hash_page[]; + extern unsigned int flush_hash_patch_A[], flush_hash_patch_B[]; + + if (!mmu_has_feature(MMU_FTR_HPTE_TABLE)) { + /* + * Put a blr (procedure return) instruction at the + * start of hash_page, since we can still get DSI + * exceptions on a 603. + */ + hash_page[0] = 0x4e800020; + flush_icache_range((unsigned long) &hash_page[0], + (unsigned long) &hash_page[1]); + return; + } + + if ( ppc_md.progress ) ppc_md.progress("hash:enter", 0x105); + +#define LG_HPTEG_SIZE 6 /* 64 bytes per HPTEG */ +#define SDR1_LOW_BITS ((n_hpteg - 1) >> 10) +#define MIN_N_HPTEG 1024 /* min 64kB hash table */ + + /* + * Allow 1 HPTE (1/8 HPTEG) for each page of memory. + * This is less than the recommended amount, but then + * Linux ain't AIX. + */ + n_hpteg = total_memory / (PAGE_SIZE * 8); + if (n_hpteg < MIN_N_HPTEG) + n_hpteg = MIN_N_HPTEG; + lg_n_hpteg = __ilog2(n_hpteg); + if (n_hpteg & (n_hpteg - 1)) { + ++lg_n_hpteg; /* round up if not power of 2 */ + n_hpteg = 1 << lg_n_hpteg; + } + Hash_size = n_hpteg << LG_HPTEG_SIZE; + + /* + * Find some memory for the hash table. + */ + if ( ppc_md.progress ) ppc_md.progress("hash:find piece", 0x322); + Hash = __va(memblock_alloc(Hash_size, Hash_size)); + memset(Hash, 0, Hash_size); + _SDR1 = __pa(Hash) | SDR1_LOW_BITS; + + Hash_end = (struct hash_pte *) ((unsigned long)Hash + Hash_size); + + printk("Total memory = %lldMB; using %ldkB for hash table (at %p)\n", + (unsigned long long)(total_memory >> 20), Hash_size >> 10, Hash); + + + /* + * Patch up the instructions in hashtable.S:create_hpte + */ + if ( ppc_md.progress ) ppc_md.progress("hash:patch", 0x345); + Hash_mask = n_hpteg - 1; + hmask = Hash_mask >> (16 - LG_HPTEG_SIZE); + mb2 = mb = 32 - LG_HPTEG_SIZE - lg_n_hpteg; + if (lg_n_hpteg > 16) + mb2 = 16 - LG_HPTEG_SIZE; + + hash_page_patch_A[0] = (hash_page_patch_A[0] & ~0xffff) + | ((unsigned int)(Hash) >> 16); + hash_page_patch_A[1] = (hash_page_patch_A[1] & ~0x7c0) | (mb << 6); + hash_page_patch_A[2] = (hash_page_patch_A[2] & ~0x7c0) | (mb2 << 6); + hash_page_patch_B[0] = (hash_page_patch_B[0] & ~0xffff) | hmask; + hash_page_patch_C[0] = (hash_page_patch_C[0] & ~0xffff) | hmask; + + /* + * Ensure that the locations we've patched have been written + * out from the data cache and invalidated in the instruction + * cache, on those machines with split caches. + */ + flush_icache_range((unsigned long) &hash_page_patch_A[0], + (unsigned long) &hash_page_patch_C[1]); + + /* + * Patch up the instructions in hashtable.S:flush_hash_page + */ + flush_hash_patch_A[0] = (flush_hash_patch_A[0] & ~0xffff) + | ((unsigned int)(Hash) >> 16); + flush_hash_patch_A[1] = (flush_hash_patch_A[1] & ~0x7c0) | (mb << 6); + flush_hash_patch_A[2] = (flush_hash_patch_A[2] & ~0x7c0) | (mb2 << 6); + flush_hash_patch_B[0] = (flush_hash_patch_B[0] & ~0xffff) | hmask; + flush_icache_range((unsigned long) &flush_hash_patch_A[0], + (unsigned long) &flush_hash_patch_B[1]); + + if ( ppc_md.progress ) ppc_md.progress("hash:done", 0x205); +} + +void setup_initial_memory_limit(phys_addr_t first_memblock_base, + phys_addr_t first_memblock_size) +{ + /* We don't currently support the first MEMBLOCK not mapping 0 + * physical on those processors + */ + BUG_ON(first_memblock_base != 0); + + /* 601 can only access 16MB at the moment */ + if (PVR_VER(mfspr(SPRN_PVR)) == 1) + memblock_set_current_limit(min_t(u64, first_memblock_size, 0x01000000)); + else /* Anything else has 256M mapped */ + memblock_set_current_limit(min_t(u64, first_memblock_size, 0x10000000)); +} |