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 000000000000..d855fec26317
--- /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++;
+        }
+}
+
+