diff options
Diffstat (limited to 'arch/powerpc/mm/pgtable.c')
-rw-r--r-- | arch/powerpc/mm/pgtable.c | 470 |
1 files changed, 470 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c new file mode 100644 index 0000000..81a3d74 --- /dev/null +++ b/arch/powerpc/mm/pgtable.c @@ -0,0 +1,470 @@ +/* + * This file contains the routines setting up the linux page tables. + * -- 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 + * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk). + * + * 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/config.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/vmalloc.h> +#include <linux/init.h> +#include <linux/highmem.h> + +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/io.h> + +#include "mmu_decl.h" + +unsigned long ioremap_base; +unsigned long ioremap_bot; +int io_bat_index; + +#if defined(CONFIG_6xx) || defined(CONFIG_POWER3) +#define HAVE_BATS 1 +#endif + +#if defined(CONFIG_FSL_BOOKE) +#define HAVE_TLBCAM 1 +#endif + +extern char etext[], _stext[]; + +#ifdef CONFIG_SMP +extern void hash_page_sync(void); +#endif + +#ifdef HAVE_BATS +extern unsigned long v_mapped_by_bats(unsigned long va); +extern unsigned long p_mapped_by_bats(unsigned long pa); +void setbat(int index, unsigned long virt, unsigned long phys, + unsigned int size, int flags); + +#else /* !HAVE_BATS */ +#define v_mapped_by_bats(x) (0UL) +#define p_mapped_by_bats(x) (0UL) +#endif /* HAVE_BATS */ + +#ifdef HAVE_TLBCAM +extern unsigned int tlbcam_index; +extern unsigned long v_mapped_by_tlbcam(unsigned long va); +extern unsigned long p_mapped_by_tlbcam(unsigned long pa); +#else /* !HAVE_TLBCAM */ +#define v_mapped_by_tlbcam(x) (0UL) +#define p_mapped_by_tlbcam(x) (0UL) +#endif /* HAVE_TLBCAM */ + +#ifdef CONFIG_PTE_64BIT +/* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ +#define PGDIR_ORDER 1 +#else +#define PGDIR_ORDER 0 +#endif + +pgd_t *pgd_alloc(struct mm_struct *mm) +{ + pgd_t *ret; + + ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER); + return ret; +} + +void pgd_free(pgd_t *pgd) +{ + free_pages((unsigned long)pgd, PGDIR_ORDER); +} + +pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) +{ + pte_t *pte; + extern int mem_init_done; + extern void *early_get_page(void); + + if (mem_init_done) { + pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); + } else { + pte = (pte_t *)early_get_page(); + if (pte) + clear_page(pte); + } + return pte; +} + +struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) +{ + struct page *ptepage; + +#ifdef CONFIG_HIGHPTE + int flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT; +#else + int flags = GFP_KERNEL | __GFP_REPEAT; +#endif + + ptepage = alloc_pages(flags, 0); + if (ptepage) + clear_highpage(ptepage); + return ptepage; +} + +void pte_free_kernel(pte_t *pte) +{ +#ifdef CONFIG_SMP + hash_page_sync(); +#endif + free_page((unsigned long)pte); +} + +void pte_free(struct page *ptepage) +{ +#ifdef CONFIG_SMP + hash_page_sync(); +#endif + __free_page(ptepage); +} + +#ifndef CONFIG_PHYS_64BIT +void __iomem * +ioremap(phys_addr_t addr, unsigned long size) +{ + return __ioremap(addr, size, _PAGE_NO_CACHE); +} +#else /* CONFIG_PHYS_64BIT */ +void __iomem * +ioremap64(unsigned long long addr, unsigned long size) +{ + return __ioremap(addr, size, _PAGE_NO_CACHE); +} + +void __iomem * +ioremap(phys_addr_t addr, unsigned long size) +{ + phys_addr_t addr64 = fixup_bigphys_addr(addr, size); + + return ioremap64(addr64, size); +} +#endif /* CONFIG_PHYS_64BIT */ + +void __iomem * +__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) +{ + unsigned long v, i; + phys_addr_t p; + int err; + + /* + * Choose an address to map it to. + * Once the vmalloc system is running, we use it. + * Before then, we use space going down from ioremap_base + * (ioremap_bot records where we're up to). + */ + p = addr & PAGE_MASK; + size = PAGE_ALIGN(addr + size) - p; + + /* + * If the address lies within the first 16 MB, assume it's in ISA + * memory space + */ + if (p < 16*1024*1024) + p += _ISA_MEM_BASE; + + /* + * Don't allow anybody to remap normal RAM that we're using. + * mem_init() sets high_memory so only do the check after that. + */ + if ( mem_init_done && (p < virt_to_phys(high_memory)) ) + { + printk("__ioremap(): phys addr "PHYS_FMT" is RAM lr %p\n", p, + __builtin_return_address(0)); + return NULL; + } + + if (size == 0) + return NULL; + + /* + * Is it already mapped? Perhaps overlapped by a previous + * BAT mapping. If the whole area is mapped then we're done, + * otherwise remap it since we want to keep the virt addrs for + * each request contiguous. + * + * We make the assumption here that if the bottom and top + * of the range we want are mapped then it's mapped to the + * same virt address (and this is contiguous). + * -- Cort + */ + if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) + goto out; + + if ((v = p_mapped_by_tlbcam(p))) + goto out; + + if (mem_init_done) { + struct vm_struct *area; + area = get_vm_area(size, VM_IOREMAP); + if (area == 0) + return NULL; + v = (unsigned long) area->addr; + } else { + v = (ioremap_bot -= size); + } + + if ((flags & _PAGE_PRESENT) == 0) + flags |= _PAGE_KERNEL; + if (flags & _PAGE_NO_CACHE) + flags |= _PAGE_GUARDED; + + /* + * Should check if it is a candidate for a BAT mapping + */ + + err = 0; + for (i = 0; i < size && err == 0; i += PAGE_SIZE) + err = map_page(v+i, p+i, flags); + if (err) { + if (mem_init_done) + vunmap((void *)v); + return NULL; + } + +out: + return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); +} + +void iounmap(volatile void __iomem *addr) +{ + /* + * If mapped by BATs then there is nothing to do. + * Calling vfree() generates a benign warning. + */ + if (v_mapped_by_bats((unsigned long)addr)) return; + + if (addr > high_memory && (unsigned long) addr < ioremap_bot) + vunmap((void *) (PAGE_MASK & (unsigned long)addr)); +} + +void __iomem *ioport_map(unsigned long port, unsigned int len) +{ + return (void __iomem *) (port + _IO_BASE); +} + +void ioport_unmap(void __iomem *addr) +{ + /* Nothing to do */ +} +EXPORT_SYMBOL(ioport_map); +EXPORT_SYMBOL(ioport_unmap); + +int +map_page(unsigned long va, phys_addr_t pa, int flags) +{ + pmd_t *pd; + pte_t *pg; + int err = -ENOMEM; + + spin_lock(&init_mm.page_table_lock); + /* Use upper 10 bits of VA to index the first level map */ + pd = pmd_offset(pgd_offset_k(va), va); + /* Use middle 10 bits of VA to index the second-level map */ + pg = pte_alloc_kernel(&init_mm, pd, va); + if (pg != 0) { + err = 0; + set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags))); + if (mem_init_done) + flush_HPTE(0, va, pmd_val(*pd)); + } + spin_unlock(&init_mm.page_table_lock); + return err; +} + +/* + * Map in all of physical memory starting at KERNELBASE. + */ +void __init mapin_ram(void) +{ + unsigned long v, p, s, f; + + s = mmu_mapin_ram(); + v = KERNELBASE + s; + p = PPC_MEMSTART + s; + for (; s < total_lowmem; s += PAGE_SIZE) { + if ((char *) v >= _stext && (char *) v < etext) + f = _PAGE_RAM_TEXT; + else + f = _PAGE_RAM; + map_page(v, p, f); + v += PAGE_SIZE; + p += PAGE_SIZE; + } +} + +/* is x a power of 2? */ +#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) + +/* is x a power of 4? */ +#define is_power_of_4(x) ((x) != 0 && (((x) & (x-1)) == 0) && (ffs(x) & 1)) + +/* + * Set up a mapping for a block of I/O. + * virt, phys, size must all be page-aligned. + * This should only be called before ioremap is called. + */ +void __init io_block_mapping(unsigned long virt, phys_addr_t phys, + unsigned int size, int flags) +{ + int i; + + if (virt > KERNELBASE && virt < ioremap_bot) + ioremap_bot = ioremap_base = virt; + +#ifdef HAVE_BATS + /* + * Use a BAT for this if possible... + */ + if (io_bat_index < 2 && is_power_of_2(size) + && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { + setbat(io_bat_index, virt, phys, size, flags); + ++io_bat_index; + return; + } +#endif /* HAVE_BATS */ + +#ifdef HAVE_TLBCAM + /* + * Use a CAM for this if possible... + */ + if (tlbcam_index < num_tlbcam_entries && is_power_of_4(size) + && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { + settlbcam(tlbcam_index, virt, phys, size, flags, 0); + ++tlbcam_index; + return; + } +#endif /* HAVE_TLBCAM */ + + /* No BATs available, put it in the page tables. */ + for (i = 0; i < size; i += PAGE_SIZE) + map_page(virt + i, phys + i, flags); +} + +/* Scan the real Linux page tables and return a PTE pointer for + * a virtual address in a context. + * Returns true (1) if PTE was found, zero otherwise. The pointer to + * the PTE pointer is unmodified if PTE is not found. + */ +int +get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep) +{ + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + int retval = 0; + + pgd = pgd_offset(mm, addr & PAGE_MASK); + if (pgd) { + pmd = pmd_offset(pgd, addr & PAGE_MASK); + if (pmd_present(*pmd)) { + pte = pte_offset_map(pmd, addr & PAGE_MASK); + if (pte) { + retval = 1; + *ptep = pte; + /* XXX caller needs to do pte_unmap, yuck */ + } + } + } + return(retval); +} + +/* Find physical address for this virtual address. Normally used by + * I/O functions, but anyone can call it. + */ +unsigned long iopa(unsigned long addr) +{ + unsigned long pa; + + /* I don't know why this won't work on PMacs or CHRP. It + * appears there is some bug, or there is some implicit + * mapping done not properly represented by BATs or in page + * tables.......I am actively working on resolving this, but + * can't hold up other stuff. -- Dan + */ + pte_t *pte; + struct mm_struct *mm; + + /* Check the BATs */ + pa = v_mapped_by_bats(addr); + if (pa) + return pa; + + /* Allow mapping of user addresses (within the thread) + * for DMA if necessary. + */ + if (addr < TASK_SIZE) + mm = current->mm; + else + mm = &init_mm; + + pa = 0; + if (get_pteptr(mm, addr, &pte)) { + pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); + pte_unmap(pte); + } + + return(pa); +} + +/* This is will find the virtual address for a physical one.... + * Swiped from APUS, could be dangerous :-). + * This is only a placeholder until I really find a way to make this + * work. -- Dan + */ +unsigned long +mm_ptov (unsigned long paddr) +{ + unsigned long ret; +#if 0 + if (paddr < 16*1024*1024) + ret = ZTWO_VADDR(paddr); + else { + int i; + + for (i = 0; i < kmap_chunk_count;){ + unsigned long phys = kmap_chunks[i++]; + unsigned long size = kmap_chunks[i++]; + unsigned long virt = kmap_chunks[i++]; + if (paddr >= phys + && paddr < (phys + size)){ + ret = virt + paddr - phys; + goto exit; + } + } + + ret = (unsigned long) __va(paddr); + } +exit: +#ifdef DEBUGPV + printk ("PTOV(%lx)=%lx\n", paddr, ret); +#endif +#else + ret = (unsigned long)paddr + KERNELBASE; +#endif + return ret; +} + |