/* * linux/arch/m68k/mm/motorola.c * * Routines specific to the Motorola MMU, originally from: * linux/arch/m68k/init.c * which are Copyright (C) 1995 Hamish Macdonald * * Moved 8/20/1999 Sam Creasey */ #include <linux/module.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/swap.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/types.h> #include <linux/init.h> #include <linux/bootmem.h> #include <asm/setup.h> #include <asm/uaccess.h> #include <asm/page.h> #include <asm/pgalloc.h> #include <asm/system.h> #include <asm/machdep.h> #include <asm/io.h> #include <asm/dma.h> #ifdef CONFIG_ATARI #include <asm/atari_stram.h> #endif #undef DEBUG #ifndef mm_cachebits /* * Bits to add to page descriptors for "normal" caching mode. * For 68020/030 this is 0. * For 68040, this is _PAGE_CACHE040 (cachable, copyback) */ unsigned long mm_cachebits; EXPORT_SYMBOL(mm_cachebits); #endif static pte_t * __init kernel_page_table(void) { pte_t *ptablep; ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE); clear_page(ptablep); __flush_page_to_ram(ptablep); flush_tlb_kernel_page(ptablep); nocache_page(ptablep); return ptablep; } static pmd_t *last_pgtable __initdata = NULL; pmd_t *zero_pgtable __initdata = NULL; static pmd_t * __init kernel_ptr_table(void) { if (!last_pgtable) { unsigned long pmd, last; int i; /* Find the last ptr table that was used in head.S and * reuse the remaining space in that page for further * ptr tables. */ last = (unsigned long)kernel_pg_dir; for (i = 0; i < PTRS_PER_PGD; i++) { if (!pgd_present(kernel_pg_dir[i])) continue; pmd = __pgd_page(kernel_pg_dir[i]); if (pmd > last) last = pmd; } last_pgtable = (pmd_t *)last; #ifdef DEBUG printk("kernel_ptr_init: %p\n", last_pgtable); #endif } last_pgtable += PTRS_PER_PMD; if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) { last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); clear_page(last_pgtable); __flush_page_to_ram(last_pgtable); flush_tlb_kernel_page(last_pgtable); nocache_page(last_pgtable); } return last_pgtable; } static unsigned long __init map_chunk (unsigned long addr, long size) { #define PTRTREESIZE (256*1024) #define ROOTTREESIZE (32*1024*1024) static unsigned long virtaddr = PAGE_OFFSET; unsigned long physaddr; pgd_t *pgd_dir; pmd_t *pmd_dir; pte_t *pte_dir; physaddr = (addr | m68k_supervisor_cachemode | _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY); if (CPU_IS_040_OR_060) physaddr |= _PAGE_GLOBAL040; while (size > 0) { #ifdef DEBUG if (!(virtaddr & (PTRTREESIZE-1))) printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK, virtaddr); #endif pgd_dir = pgd_offset_k(virtaddr); if (virtaddr && CPU_IS_020_OR_030) { if (!(virtaddr & (ROOTTREESIZE-1)) && size >= ROOTTREESIZE) { #ifdef DEBUG printk ("[very early term]"); #endif pgd_val(*pgd_dir) = physaddr; size -= ROOTTREESIZE; virtaddr += ROOTTREESIZE; physaddr += ROOTTREESIZE; continue; } } if (!pgd_present(*pgd_dir)) { pmd_dir = kernel_ptr_table(); #ifdef DEBUG printk ("[new pointer %p]", pmd_dir); #endif pgd_set(pgd_dir, pmd_dir); } else pmd_dir = pmd_offset(pgd_dir, virtaddr); if (CPU_IS_020_OR_030) { if (virtaddr) { #ifdef DEBUG printk ("[early term]"); #endif pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr; physaddr += PTRTREESIZE; } else { int i; #ifdef DEBUG printk ("[zero map]"); #endif zero_pgtable = kernel_ptr_table(); pte_dir = (pte_t *)zero_pgtable; pmd_dir->pmd[0] = virt_to_phys(pte_dir) | _PAGE_TABLE | _PAGE_ACCESSED; pte_val(*pte_dir++) = 0; physaddr += PAGE_SIZE; for (i = 1; i < 64; physaddr += PAGE_SIZE, i++) pte_val(*pte_dir++) = physaddr; } size -= PTRTREESIZE; virtaddr += PTRTREESIZE; } else { if (!pmd_present(*pmd_dir)) { #ifdef DEBUG printk ("[new table]"); #endif pte_dir = kernel_page_table(); pmd_set(pmd_dir, pte_dir); } pte_dir = pte_offset_kernel(pmd_dir, virtaddr); if (virtaddr) { if (!pte_present(*pte_dir)) pte_val(*pte_dir) = physaddr; } else pte_val(*pte_dir) = 0; size -= PAGE_SIZE; virtaddr += PAGE_SIZE; physaddr += PAGE_SIZE; } } #ifdef DEBUG printk("\n"); #endif return virtaddr; } /* * paging_init() continues the virtual memory environment setup which * was begun by the code in arch/head.S. */ void __init paging_init(void) { int chunk; unsigned long mem_avail = 0; unsigned long zones_size[MAX_NR_ZONES] = { 0, }; #ifdef DEBUG { extern unsigned long availmem; printk ("start of paging_init (%p, %lx, %lx, %lx)\n", kernel_pg_dir, availmem, start_mem, end_mem); } #endif /* Fix the cache mode in the page descriptors for the 680[46]0. */ if (CPU_IS_040_OR_060) { int i; #ifndef mm_cachebits mm_cachebits = _PAGE_CACHE040; #endif for (i = 0; i < 16; i++) pgprot_val(protection_map[i]) |= _PAGE_CACHE040; } /* * Map the physical memory available into the kernel virtual * address space. It may allocate some memory for page * tables and thus modify availmem. */ for (chunk = 0; chunk < m68k_num_memory; chunk++) { mem_avail = map_chunk (m68k_memory[chunk].addr, m68k_memory[chunk].size); } flush_tlb_all(); #ifdef DEBUG printk ("memory available is %ldKB\n", mem_avail >> 10); printk ("start_mem is %#lx\nvirtual_end is %#lx\n", start_mem, end_mem); #endif /* * initialize the bad page table and bad page to point * to a couple of allocated pages */ empty_zero_page = alloc_bootmem_pages(PAGE_SIZE); memset(empty_zero_page, 0, PAGE_SIZE); /* * Set up SFC/DFC registers */ set_fs(KERNEL_DS); #ifdef DEBUG printk ("before free_area_init\n"); #endif zones_size[ZONE_DMA] = (mach_max_dma_address < (unsigned long)high_memory ? (mach_max_dma_address+1) : (unsigned long)high_memory); zones_size[ZONE_NORMAL] = (unsigned long)high_memory - zones_size[0]; zones_size[ZONE_DMA] = (zones_size[ZONE_DMA] - PAGE_OFFSET) >> PAGE_SHIFT; zones_size[ZONE_NORMAL] >>= PAGE_SHIFT; free_area_init(zones_size); } extern char __init_begin, __init_end; void free_initmem(void) { unsigned long addr; addr = (unsigned long)&__init_begin; for (; addr < (unsigned long)&__init_end; addr += PAGE_SIZE) { virt_to_page(addr)->flags &= ~(1 << PG_reserved); init_page_count(virt_to_page(addr)); free_page(addr); totalram_pages++; } }