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-rw-r--r--arch/powerpc/mm/pgtable.c470
1 files changed, 470 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
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+++ b/arch/powerpc/mm/pgtable.c
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+/*
+ * 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;
+}
+
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.