ef22d8abd8
The Motorola 68xxx MMUs, 040 (and later) have a fixed 7,7,{5,6}
page-table setup, where the last depends on the page-size selected (8k
vs 4k resp.), and head.S selects 4K pages. For 030 (and earlier) we
explicitly program 7,7,6 and 4K pages in %tc.
However, the current code implements this mightily weird. What it does
is group 16 of those (6 bit) pte tables into one 4k page to not waste
space. The down-side is that that forces pmd_t to be a 16-tuple
pointing to consecutive pte tables.
This breaks the generic code which assumes READ_ONCE(*pmd) will be
word sized.
Therefore implement a straight forward 7,7,6 3 level page-table setup,
with the addition (for 020/030) of (partial) large-page support. For
now this increases the memory footprint for pte-tables 15 fold.
Tested with ARAnyM/68040 emulation.
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Greg Ungerer <gerg@linux-m68k.org>
Link: https://lore.kernel.org/r/20200131125403.711478295@infradead.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
393 lines
8.4 KiB
C
393 lines
8.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/arch/m68k/mm/kmap.c
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*
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* Copyright (C) 1997 Roman Hodek
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*
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* 10/01/99 cleaned up the code and changing to the same interface
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* used by other architectures /Roman Zippel
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*/
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <asm/setup.h>
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#include <asm/segment.h>
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#include <asm/page.h>
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#include <asm/pgalloc.h>
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#include <asm/io.h>
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#undef DEBUG
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/*
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* For 040/060 we can use the virtual memory area like other architectures,
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* but for 020/030 we want to use early termination page descriptors and we
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* can't mix this with normal page descriptors, so we have to copy that code
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* (mm/vmalloc.c) and return appropriately aligned addresses.
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*/
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#ifdef CPU_M68040_OR_M68060_ONLY
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#define IO_SIZE PAGE_SIZE
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static inline struct vm_struct *get_io_area(unsigned long size)
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{
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return get_vm_area(size, VM_IOREMAP);
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}
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static inline void free_io_area(void *addr)
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{
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vfree((void *)(PAGE_MASK & (unsigned long)addr));
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}
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#else
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#define IO_SIZE PMD_SIZE
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static struct vm_struct *iolist;
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/*
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* __free_io_area unmaps nearly everything, so be careful
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* Currently it doesn't free pointer/page tables anymore but this
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* wasn't used anyway and might be added later.
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*/
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static void __free_io_area(void *addr, unsigned long size)
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{
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unsigned long virtaddr = (unsigned long)addr;
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pgd_t *pgd_dir;
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p4d_t *p4d_dir;
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pud_t *pud_dir;
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pmd_t *pmd_dir;
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pte_t *pte_dir;
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while ((long)size > 0) {
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pgd_dir = pgd_offset_k(virtaddr);
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p4d_dir = p4d_offset(pgd_dir, virtaddr);
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pud_dir = pud_offset(p4d_dir, virtaddr);
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if (pud_bad(*pud_dir)) {
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printk("iounmap: bad pud(%08lx)\n", pud_val(*pud_dir));
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pud_clear(pud_dir);
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return;
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}
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pmd_dir = pmd_offset(pud_dir, virtaddr);
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#if CONFIG_PGTABLE_LEVELS == 3
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if (CPU_IS_020_OR_030) {
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int pmd_type = pmd_val(*pmd_dir) & _DESCTYPE_MASK;
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if (pmd_type == _PAGE_PRESENT) {
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pmd_clear(pmd_dir);
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virtaddr += PMD_SIZE;
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size -= PMD_SIZE;
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} else if (pmd_type == 0)
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continue;
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}
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#endif
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if (pmd_bad(*pmd_dir)) {
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printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
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pmd_clear(pmd_dir);
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return;
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}
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pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
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pte_val(*pte_dir) = 0;
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virtaddr += PAGE_SIZE;
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size -= PAGE_SIZE;
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}
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flush_tlb_all();
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}
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static struct vm_struct *get_io_area(unsigned long size)
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{
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unsigned long addr;
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struct vm_struct **p, *tmp, *area;
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area = kmalloc(sizeof(*area), GFP_KERNEL);
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if (!area)
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return NULL;
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addr = KMAP_START;
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for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
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if (size + addr < (unsigned long)tmp->addr)
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break;
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if (addr > KMAP_END-size) {
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kfree(area);
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return NULL;
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}
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addr = tmp->size + (unsigned long)tmp->addr;
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}
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area->addr = (void *)addr;
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area->size = size + IO_SIZE;
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area->next = *p;
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*p = area;
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return area;
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}
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static inline void free_io_area(void *addr)
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{
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struct vm_struct **p, *tmp;
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if (!addr)
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return;
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addr = (void *)((unsigned long)addr & -IO_SIZE);
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for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
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if (tmp->addr == addr) {
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*p = tmp->next;
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/* remove gap added in get_io_area() */
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__free_io_area(tmp->addr, tmp->size - IO_SIZE);
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kfree(tmp);
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return;
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}
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}
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}
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#endif
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/*
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* Map some physical address range into the kernel address space.
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*/
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/* Rewritten by Andreas Schwab to remove all races. */
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void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
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{
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struct vm_struct *area;
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unsigned long virtaddr, retaddr;
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long offset;
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pgd_t *pgd_dir;
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p4d_t *p4d_dir;
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pud_t *pud_dir;
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pmd_t *pmd_dir;
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pte_t *pte_dir;
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/*
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* Don't allow mappings that wrap..
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*/
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if (!size || physaddr > (unsigned long)(-size))
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return NULL;
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#ifdef CONFIG_AMIGA
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if (MACH_IS_AMIGA) {
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if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
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&& (cacheflag == IOMAP_NOCACHE_SER))
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return (void __iomem *)physaddr;
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}
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#endif
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#ifdef CONFIG_COLDFIRE
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if (__cf_internalio(physaddr))
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return (void __iomem *) physaddr;
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#endif
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#ifdef DEBUG
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printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
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#endif
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/*
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* Mappings have to be aligned
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*/
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offset = physaddr & (IO_SIZE - 1);
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physaddr &= -IO_SIZE;
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size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
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/*
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* Ok, go for it..
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*/
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area = get_io_area(size);
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if (!area)
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return NULL;
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virtaddr = (unsigned long)area->addr;
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retaddr = virtaddr + offset;
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#ifdef DEBUG
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printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
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#endif
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/*
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* add cache and table flags to physical address
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*/
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if (CPU_IS_040_OR_060) {
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physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
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_PAGE_ACCESSED | _PAGE_DIRTY);
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switch (cacheflag) {
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case IOMAP_FULL_CACHING:
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physaddr |= _PAGE_CACHE040;
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break;
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case IOMAP_NOCACHE_SER:
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default:
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physaddr |= _PAGE_NOCACHE_S;
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break;
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case IOMAP_NOCACHE_NONSER:
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physaddr |= _PAGE_NOCACHE;
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break;
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case IOMAP_WRITETHROUGH:
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physaddr |= _PAGE_CACHE040W;
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break;
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}
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} else {
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physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED |
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_PAGE_DIRTY | _PAGE_READWRITE);
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switch (cacheflag) {
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case IOMAP_NOCACHE_SER:
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case IOMAP_NOCACHE_NONSER:
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default:
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physaddr |= _PAGE_NOCACHE030;
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break;
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case IOMAP_FULL_CACHING:
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case IOMAP_WRITETHROUGH:
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break;
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}
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}
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while ((long)size > 0) {
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#ifdef DEBUG
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if (!(virtaddr & (PMD_SIZE-1)))
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printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
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#endif
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pgd_dir = pgd_offset_k(virtaddr);
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p4d_dir = p4d_offset(pgd_dir, virtaddr);
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pud_dir = pud_offset(p4d_dir, virtaddr);
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pmd_dir = pmd_alloc(&init_mm, pud_dir, virtaddr);
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if (!pmd_dir) {
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printk("ioremap: no mem for pmd_dir\n");
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return NULL;
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}
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#if CONFIG_PGTABLE_LEVELS == 3
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if (CPU_IS_020_OR_030) {
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pmd_val(*pmd_dir) = physaddr;
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physaddr += PMD_SIZE;
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virtaddr += PMD_SIZE;
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size -= PMD_SIZE;
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} else
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#endif
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{
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pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
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if (!pte_dir) {
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printk("ioremap: no mem for pte_dir\n");
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return NULL;
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}
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pte_val(*pte_dir) = physaddr;
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virtaddr += PAGE_SIZE;
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physaddr += PAGE_SIZE;
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size -= PAGE_SIZE;
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}
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}
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#ifdef DEBUG
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printk("\n");
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#endif
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flush_tlb_all();
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return (void __iomem *)retaddr;
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}
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EXPORT_SYMBOL(__ioremap);
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/*
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* Unmap an ioremap()ed region again
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*/
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void iounmap(void __iomem *addr)
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{
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#ifdef CONFIG_AMIGA
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if ((!MACH_IS_AMIGA) ||
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(((unsigned long)addr < 0x40000000) ||
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((unsigned long)addr > 0x60000000)))
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free_io_area((__force void *)addr);
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#else
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#ifdef CONFIG_COLDFIRE
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if (cf_internalio(addr))
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return;
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#endif
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free_io_area((__force void *)addr);
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#endif
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}
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EXPORT_SYMBOL(iounmap);
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/*
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* Set new cache mode for some kernel address space.
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* The caller must push data for that range itself, if such data may already
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* be in the cache.
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*/
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void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
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{
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unsigned long virtaddr = (unsigned long)addr;
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pgd_t *pgd_dir;
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p4d_t *p4d_dir;
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pud_t *pud_dir;
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pmd_t *pmd_dir;
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pte_t *pte_dir;
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if (CPU_IS_040_OR_060) {
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switch (cmode) {
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case IOMAP_FULL_CACHING:
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cmode = _PAGE_CACHE040;
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break;
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case IOMAP_NOCACHE_SER:
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default:
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cmode = _PAGE_NOCACHE_S;
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break;
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case IOMAP_NOCACHE_NONSER:
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cmode = _PAGE_NOCACHE;
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break;
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case IOMAP_WRITETHROUGH:
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cmode = _PAGE_CACHE040W;
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break;
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}
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} else {
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switch (cmode) {
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case IOMAP_NOCACHE_SER:
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case IOMAP_NOCACHE_NONSER:
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default:
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cmode = _PAGE_NOCACHE030;
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break;
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case IOMAP_FULL_CACHING:
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case IOMAP_WRITETHROUGH:
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cmode = 0;
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}
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}
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while ((long)size > 0) {
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pgd_dir = pgd_offset_k(virtaddr);
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p4d_dir = p4d_offset(pgd_dir, virtaddr);
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pud_dir = pud_offset(p4d_dir, virtaddr);
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if (pud_bad(*pud_dir)) {
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printk("iocachemode: bad pud(%08lx)\n", pud_val(*pud_dir));
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pud_clear(pud_dir);
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return;
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}
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pmd_dir = pmd_offset(pud_dir, virtaddr);
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#if CONFIG_PGTABLE_LEVELS == 3
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if (CPU_IS_020_OR_030) {
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unsigned long pmd = pmd_val(*pmd_dir);
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if ((pmd & _DESCTYPE_MASK) == _PAGE_PRESENT) {
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*pmd_dir = __pmd((pmd & _CACHEMASK040) | cmode);
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virtaddr += PMD_SIZE;
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size -= PMD_SIZE;
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continue;
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}
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}
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#endif
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if (pmd_bad(*pmd_dir)) {
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printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
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pmd_clear(pmd_dir);
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return;
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}
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pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
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pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
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virtaddr += PAGE_SIZE;
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size -= PAGE_SIZE;
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}
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flush_tlb_all();
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}
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EXPORT_SYMBOL(kernel_set_cachemode);
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