--- /dev/null
+/*
+ * 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));
+}
Code Review / kvmfornfv.git / blobdiff