514 строки
13 KiB
C
514 строки
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/arch/m68k/mm/motorola.c
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*
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* Routines specific to the Motorola MMU, originally from:
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* linux/arch/m68k/init.c
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* which are Copyright (C) 1995 Hamish Macdonald
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*
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* Moved 8/20/1999 Sam Creasey
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*/
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#include <linux/module.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/swap.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/init.h>
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#include <linux/memblock.h>
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#include <linux/gfp.h>
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#include <asm/setup.h>
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#include <linux/uaccess.h>
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#include <asm/page.h>
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#include <asm/pgalloc.h>
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#include <asm/machdep.h>
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#include <asm/io.h>
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#ifdef CONFIG_ATARI
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#include <asm/atari_stram.h>
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#endif
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#include <asm/sections.h>
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#undef DEBUG
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#ifndef mm_cachebits
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/*
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* Bits to add to page descriptors for "normal" caching mode.
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* For 68020/030 this is 0.
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* For 68040, this is _PAGE_CACHE040 (cachable, copyback)
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*/
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unsigned long mm_cachebits;
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EXPORT_SYMBOL(mm_cachebits);
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#endif
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/* Prior to calling these routines, the page should have been flushed
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* from both the cache and ATC, or the CPU might not notice that the
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* cache setting for the page has been changed. -jskov
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*/
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static inline void nocache_page(void *vaddr)
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{
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unsigned long addr = (unsigned long)vaddr;
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if (CPU_IS_040_OR_060) {
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pte_t *ptep = virt_to_kpte(addr);
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*ptep = pte_mknocache(*ptep);
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}
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}
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static inline void cache_page(void *vaddr)
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{
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unsigned long addr = (unsigned long)vaddr;
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if (CPU_IS_040_OR_060) {
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pte_t *ptep = virt_to_kpte(addr);
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*ptep = pte_mkcache(*ptep);
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}
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}
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/*
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* Motorola 680x0 user's manual recommends using uncached memory for address
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* translation tables.
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*
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* Seeing how the MMU can be external on (some of) these chips, that seems like
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* a very important recommendation to follow. Provide some helpers to combat
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* 'variation' amongst the users of this.
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*/
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void mmu_page_ctor(void *page)
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{
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__flush_page_to_ram(page);
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flush_tlb_kernel_page(page);
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nocache_page(page);
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}
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void mmu_page_dtor(void *page)
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{
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cache_page(page);
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}
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/* ++andreas: {get,free}_pointer_table rewritten to use unused fields from
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struct page instead of separately kmalloced struct. Stolen from
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arch/sparc/mm/srmmu.c ... */
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typedef struct list_head ptable_desc;
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static struct list_head ptable_list[2] = {
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LIST_HEAD_INIT(ptable_list[0]),
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LIST_HEAD_INIT(ptable_list[1]),
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};
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#define PD_PTABLE(page) ((ptable_desc *)&(virt_to_page(page)->lru))
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#define PD_PAGE(ptable) (list_entry(ptable, struct page, lru))
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#define PD_MARKBITS(dp) (*(unsigned int *)&PD_PAGE(dp)->index)
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static const int ptable_shift[2] = {
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7+2, /* PGD, PMD */
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6+2, /* PTE */
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};
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#define ptable_size(type) (1U << ptable_shift[type])
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#define ptable_mask(type) ((1U << (PAGE_SIZE / ptable_size(type))) - 1)
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void __init init_pointer_table(void *table, int type)
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{
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ptable_desc *dp;
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unsigned long ptable = (unsigned long)table;
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unsigned long page = ptable & PAGE_MASK;
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unsigned int mask = 1U << ((ptable - page)/ptable_size(type));
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dp = PD_PTABLE(page);
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if (!(PD_MARKBITS(dp) & mask)) {
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PD_MARKBITS(dp) = ptable_mask(type);
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list_add(dp, &ptable_list[type]);
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}
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PD_MARKBITS(dp) &= ~mask;
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pr_debug("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp));
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/* unreserve the page so it's possible to free that page */
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__ClearPageReserved(PD_PAGE(dp));
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init_page_count(PD_PAGE(dp));
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return;
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}
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void *get_pointer_table(int type)
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{
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ptable_desc *dp = ptable_list[type].next;
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unsigned int mask = list_empty(&ptable_list[type]) ? 0 : PD_MARKBITS(dp);
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unsigned int tmp, off;
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/*
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* For a pointer table for a user process address space, a
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* table is taken from a page allocated for the purpose. Each
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* page can hold 8 pointer tables. The page is remapped in
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* virtual address space to be noncacheable.
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*/
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if (mask == 0) {
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void *page;
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ptable_desc *new;
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if (!(page = (void *)get_zeroed_page(GFP_KERNEL)))
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return NULL;
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if (type == TABLE_PTE) {
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/*
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* m68k doesn't have SPLIT_PTE_PTLOCKS for not having
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* SMP.
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*/
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pgtable_pte_page_ctor(virt_to_page(page));
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}
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mmu_page_ctor(page);
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new = PD_PTABLE(page);
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PD_MARKBITS(new) = ptable_mask(type) - 1;
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list_add_tail(new, dp);
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return (pmd_t *)page;
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}
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for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += ptable_size(type))
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;
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PD_MARKBITS(dp) = mask & ~tmp;
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if (!PD_MARKBITS(dp)) {
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/* move to end of list */
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list_move_tail(dp, &ptable_list[type]);
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}
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return page_address(PD_PAGE(dp)) + off;
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}
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int free_pointer_table(void *table, int type)
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{
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ptable_desc *dp;
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unsigned long ptable = (unsigned long)table;
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unsigned long page = ptable & PAGE_MASK;
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unsigned int mask = 1U << ((ptable - page)/ptable_size(type));
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dp = PD_PTABLE(page);
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if (PD_MARKBITS (dp) & mask)
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panic ("table already free!");
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PD_MARKBITS (dp) |= mask;
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if (PD_MARKBITS(dp) == ptable_mask(type)) {
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/* all tables in page are free, free page */
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list_del(dp);
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mmu_page_dtor((void *)page);
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if (type == TABLE_PTE)
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pgtable_pte_page_dtor(virt_to_page(page));
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free_page (page);
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return 1;
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} else if (ptable_list[type].next != dp) {
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/*
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* move this descriptor to the front of the list, since
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* it has one or more free tables.
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*/
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list_move(dp, &ptable_list[type]);
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}
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return 0;
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}
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/* size of memory already mapped in head.S */
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extern __initdata unsigned long m68k_init_mapped_size;
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extern unsigned long availmem;
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static pte_t *last_pte_table __initdata = NULL;
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static pte_t * __init kernel_page_table(void)
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{
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pte_t *pte_table = last_pte_table;
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if (PAGE_ALIGNED(last_pte_table)) {
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pte_table = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
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if (!pte_table) {
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panic("%s: Failed to allocate %lu bytes align=%lx\n",
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__func__, PAGE_SIZE, PAGE_SIZE);
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}
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clear_page(pte_table);
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mmu_page_ctor(pte_table);
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last_pte_table = pte_table;
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}
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last_pte_table += PTRS_PER_PTE;
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return pte_table;
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}
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static pmd_t *last_pmd_table __initdata = NULL;
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static pmd_t * __init kernel_ptr_table(void)
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{
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if (!last_pmd_table) {
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unsigned long pmd, last;
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int i;
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/* Find the last ptr table that was used in head.S and
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* reuse the remaining space in that page for further
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* ptr tables.
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*/
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last = (unsigned long)kernel_pg_dir;
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for (i = 0; i < PTRS_PER_PGD; i++) {
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pud_t *pud = (pud_t *)(&kernel_pg_dir[i]);
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if (!pud_present(*pud))
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continue;
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pmd = pgd_page_vaddr(kernel_pg_dir[i]);
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if (pmd > last)
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last = pmd;
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}
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last_pmd_table = (pmd_t *)last;
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#ifdef DEBUG
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printk("kernel_ptr_init: %p\n", last_pmd_table);
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#endif
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}
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last_pmd_table += PTRS_PER_PMD;
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if (PAGE_ALIGNED(last_pmd_table)) {
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last_pmd_table = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
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if (!last_pmd_table)
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panic("%s: Failed to allocate %lu bytes align=%lx\n",
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__func__, PAGE_SIZE, PAGE_SIZE);
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clear_page(last_pmd_table);
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mmu_page_ctor(last_pmd_table);
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}
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return last_pmd_table;
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}
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static void __init map_node(int node)
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{
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unsigned long physaddr, virtaddr, size;
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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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size = m68k_memory[node].size;
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physaddr = m68k_memory[node].addr;
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virtaddr = (unsigned long)phys_to_virt(physaddr);
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physaddr |= m68k_supervisor_cachemode |
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_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY;
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if (CPU_IS_040_OR_060)
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physaddr |= _PAGE_GLOBAL040;
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while (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 & PAGE_MASK,
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virtaddr);
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#endif
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pgd_dir = pgd_offset_k(virtaddr);
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if (virtaddr && CPU_IS_020_OR_030) {
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if (!(virtaddr & (PGDIR_SIZE-1)) &&
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size >= PGDIR_SIZE) {
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#ifdef DEBUG
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printk ("[very early term]");
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#endif
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pgd_val(*pgd_dir) = physaddr;
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size -= PGDIR_SIZE;
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virtaddr += PGDIR_SIZE;
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physaddr += PGDIR_SIZE;
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continue;
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}
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}
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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_present(*pud_dir)) {
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pmd_dir = kernel_ptr_table();
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#ifdef DEBUG
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printk ("[new pointer %p]", pmd_dir);
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#endif
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pud_set(pud_dir, pmd_dir);
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} else
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pmd_dir = pmd_offset(pud_dir, virtaddr);
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if (CPU_IS_020_OR_030) {
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if (virtaddr) {
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#ifdef DEBUG
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printk ("[early term]");
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#endif
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pmd_val(*pmd_dir) = physaddr;
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physaddr += PMD_SIZE;
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} else {
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int i;
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#ifdef DEBUG
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printk ("[zero map]");
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#endif
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pte_dir = kernel_page_table();
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pmd_set(pmd_dir, pte_dir);
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pte_val(*pte_dir++) = 0;
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physaddr += PAGE_SIZE;
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for (i = 1; i < PTRS_PER_PTE; physaddr += PAGE_SIZE, i++)
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pte_val(*pte_dir++) = physaddr;
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}
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size -= PMD_SIZE;
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virtaddr += PMD_SIZE;
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} else {
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if (!pmd_present(*pmd_dir)) {
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#ifdef DEBUG
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printk ("[new table]");
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#endif
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pte_dir = kernel_page_table();
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pmd_set(pmd_dir, pte_dir);
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}
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pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
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if (virtaddr) {
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if (!pte_present(*pte_dir))
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pte_val(*pte_dir) = physaddr;
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} else
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pte_val(*pte_dir) = 0;
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size -= PAGE_SIZE;
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virtaddr += PAGE_SIZE;
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physaddr += 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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}
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/*
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* Alternate definitions that are compile time constants, for
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* initializing protection_map. The cachebits are fixed later.
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*/
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#define PAGE_NONE_C __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
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#define PAGE_SHARED_C __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)
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#define PAGE_COPY_C __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)
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#define PAGE_READONLY_C __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)
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static pgprot_t protection_map[16] __ro_after_init = {
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[VM_NONE] = PAGE_NONE_C,
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[VM_READ] = PAGE_READONLY_C,
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[VM_WRITE] = PAGE_COPY_C,
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[VM_WRITE | VM_READ] = PAGE_COPY_C,
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[VM_EXEC] = PAGE_READONLY_C,
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[VM_EXEC | VM_READ] = PAGE_READONLY_C,
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[VM_EXEC | VM_WRITE] = PAGE_COPY_C,
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[VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_C,
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[VM_SHARED] = PAGE_NONE_C,
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[VM_SHARED | VM_READ] = PAGE_READONLY_C,
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[VM_SHARED | VM_WRITE] = PAGE_SHARED_C,
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[VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED_C,
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[VM_SHARED | VM_EXEC] = PAGE_READONLY_C,
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[VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_C,
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[VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_C,
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[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_C
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};
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DECLARE_VM_GET_PAGE_PROT
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/*
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* paging_init() continues the virtual memory environment setup which
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* was begun by the code in arch/head.S.
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*/
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void __init paging_init(void)
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{
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unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, };
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unsigned long min_addr, max_addr;
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unsigned long addr;
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int i;
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#ifdef DEBUG
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printk ("start of paging_init (%p, %lx)\n", kernel_pg_dir, availmem);
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#endif
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/* Fix the cache mode in the page descriptors for the 680[46]0. */
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if (CPU_IS_040_OR_060) {
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int i;
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#ifndef mm_cachebits
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mm_cachebits = _PAGE_CACHE040;
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#endif
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for (i = 0; i < 16; i++)
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pgprot_val(protection_map[i]) |= _PAGE_CACHE040;
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}
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min_addr = m68k_memory[0].addr;
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max_addr = min_addr + m68k_memory[0].size;
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memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0,
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MEMBLOCK_NONE);
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for (i = 1; i < m68k_num_memory;) {
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if (m68k_memory[i].addr < min_addr) {
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printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n",
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m68k_memory[i].addr, m68k_memory[i].size);
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printk("Fix your bootloader or use a memfile to make use of this area!\n");
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m68k_num_memory--;
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memmove(m68k_memory + i, m68k_memory + i + 1,
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(m68k_num_memory - i) * sizeof(struct m68k_mem_info));
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continue;
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}
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memblock_add_node(m68k_memory[i].addr, m68k_memory[i].size, i,
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MEMBLOCK_NONE);
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addr = m68k_memory[i].addr + m68k_memory[i].size;
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if (addr > max_addr)
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max_addr = addr;
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i++;
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}
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m68k_memoffset = min_addr - PAGE_OFFSET;
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m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6;
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module_fixup(NULL, __start_fixup, __stop_fixup);
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flush_icache();
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high_memory = phys_to_virt(max_addr);
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min_low_pfn = availmem >> PAGE_SHIFT;
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max_pfn = max_low_pfn = max_addr >> PAGE_SHIFT;
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/* Reserve kernel text/data/bss and the memory allocated in head.S */
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memblock_reserve(m68k_memory[0].addr, availmem - m68k_memory[0].addr);
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/*
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* Map the physical memory available into the kernel virtual
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* address space. Make sure memblock will not try to allocate
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* pages beyond the memory we already mapped in head.S
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*/
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memblock_set_bottom_up(true);
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for (i = 0; i < m68k_num_memory; i++) {
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m68k_setup_node(i);
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map_node(i);
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}
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flush_tlb_all();
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early_memtest(min_addr, max_addr);
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/*
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* initialize the bad page table and bad page to point
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* to a couple of allocated pages
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*/
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empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
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if (!empty_zero_page)
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panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
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__func__, PAGE_SIZE, PAGE_SIZE);
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/*
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* Set up SFC/DFC registers
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*/
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set_fc(USER_DATA);
|
|
|
|
#ifdef DEBUG
|
|
printk ("before free_area_init\n");
|
|
#endif
|
|
for (i = 0; i < m68k_num_memory; i++)
|
|
if (node_present_pages(i))
|
|
node_set_state(i, N_NORMAL_MEMORY);
|
|
|
|
max_zone_pfn[ZONE_DMA] = memblock_end_of_DRAM();
|
|
free_area_init(max_zone_pfn);
|
|
}
|