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481 lines
12 KiB
481 lines
12 KiB
// 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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#include <asm/dma.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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* 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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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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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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/* |
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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_fs(KERNEL_DS); |
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#ifdef DEBUG |
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printk ("before free_area_init\n"); |
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#endif |
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for (i = 0; i < m68k_num_memory; i++) |
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if (node_present_pages(i)) |
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node_set_state(i, N_NORMAL_MEMORY); |
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max_zone_pfn[ZONE_DMA] = memblock_end_of_DRAM(); |
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free_area_init(max_zone_pfn); |
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}
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