diff options
Diffstat (limited to 'arch/m68k/mm/motorola.c')
| -rw-r--r-- | arch/m68k/mm/motorola.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c new file mode 100644 index 0000000..d855fec --- /dev/null +++ b/arch/m68k/mm/motorola.c @@ -0,0 +1,285 @@ +/* + * linux/arch/m68k/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/config.h> +#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[3] = { 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[0] = (mach_max_dma_address < (unsigned long)high_memory ? + (mach_max_dma_address+1) : (unsigned long)high_memory); + zones_size[1] = (unsigned long)high_memory - zones_size[0]; + + zones_size[0] = (zones_size[0] - PAGE_OFFSET) >> PAGE_SHIFT; + zones_size[1] >>= 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); + set_page_count(virt_to_page(addr), 1); + free_page(addr); + totalram_pages++; + } +} + + |