patch-2.3.17 linux/arch/m68k/mm/motorola.c

• Lines: 300
• Date: Sat Sep 4 13:06:41 1999
• Orig file: v2.3.16/linux/arch/m68k/mm/motorola.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.16/linux/arch/m68k/mm/motorola.c linux/arch/m68k/mm/motorola.c
@@ -0,0 +1,299 @@
+/*
+ * 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/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>
+#ifdef CONFIG_BLK_DEV_RAM
+#include <linux/blk.h>
+#endif
+
+#include <asm/setup.h>
+#include <asm/uaccess.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/machdep.h>
+#include <asm/io.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 = 0;
+#endif
+
+static pte_t * __init kernel_page_table(unsigned long *memavailp)
+{
+	pte_t *ptablep;
+
+	ptablep = (pte_t *)*memavailp;
+	*memavailp += PAGE_SIZE;
+
+	clear_page((unsigned long)ptablep);
+	flush_page_to_ram((unsigned long) ptablep);
+	flush_tlb_kernel_page((unsigned long) ptablep);
+	nocache_page ((unsigned long)ptablep);
+
+	return ptablep;
+}
+
+static pmd_t *last_pgtable __initdata = NULL;
+pmd_t *zero_pgtable __initdata = NULL;
+
+static pmd_t * __init kernel_ptr_table(unsigned long *memavailp)
+{
+	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
+	}
+
+	if (((unsigned long)(last_pgtable + PTRS_PER_PMD) & ~PAGE_MASK) == 0) {
+		last_pgtable = (pmd_t *)*memavailp;
+		*memavailp += PAGE_SIZE;
+
+		clear_page((unsigned long)last_pgtable);
+		flush_page_to_ram((unsigned long)last_pgtable);
+		flush_tlb_kernel_page((unsigned long)last_pgtable);
+		nocache_page((unsigned long)last_pgtable);
+	} else
+		last_pgtable += PTRS_PER_PMD;
+
+	return last_pgtable;
+}
+
+static unsigned long __init 
+map_chunk (unsigned long addr, long size, unsigned long *memavailp)
+{
+#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(memavailp);
+#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(memavailp);
+				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(memavailp);
+				pmd_set(pmd_dir, pte_dir);
+			}
+			pte_dir = pte_offset(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;
+}
+
+extern unsigned long free_area_init(unsigned long, unsigned long);
+extern unsigned long empty_bad_page_table;
+extern unsigned long empty_bad_page;
+
+/*
+ * paging_init() continues the virtual memory environment setup which
+ * was begun by the code in arch/head.S.
+ */
+unsigned long __init paging_init(unsigned long start_mem,
+				 unsigned long end_mem)
+{
+	int chunk;
+	unsigned long mem_avail = 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;
+	}
+	/* Fix the PAGE_NONE value. */
+	if (CPU_IS_040_OR_060) {
+		/* On the 680[46]0 we can use the _PAGE_SUPER bit.  */
+		pgprot_val(protection_map[0]) |= _PAGE_SUPER;
+		pgprot_val(protection_map[VM_SHARED]) |= _PAGE_SUPER;
+	} else {
+		/* Otherwise we must fake it. */
+		pgprot_val(protection_map[0]) &= ~_PAGE_PRESENT;
+		pgprot_val(protection_map[0]) |= _PAGE_FAKE_SUPER;
+		pgprot_val(protection_map[VM_SHARED]) &= ~_PAGE_PRESENT;
+		pgprot_val(protection_map[VM_SHARED]) |= _PAGE_FAKE_SUPER;
+	}
+
+	/*
+	 * 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, &start_mem);
+
+	}
+
+	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_bad_page_table = start_mem;
+	start_mem += PAGE_SIZE;
+	empty_bad_page = start_mem;
+	start_mem += PAGE_SIZE;
+	empty_zero_page = start_mem;
+	start_mem += PAGE_SIZE;
+	memset((void *)empty_zero_page, 0, PAGE_SIZE);
+
+	/*
+	 * Set up SFC/DFC registers (user data space)
+	 */
+	set_fs (USER_DS);
+
+#ifdef DEBUG
+	printk ("before free_area_init\n");
+#endif
+	return PAGE_ALIGN(free_area_init(start_mem, end_mem));
+}
+
+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) {
+		mem_map[MAP_NR(addr)].flags &= ~(1 << PG_reserved);
+		set_page_count(mem_map+MAP_NR(addr), 1);
+		free_page(addr);
+	}
+}
+
+