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-rw-r--r--arch/m68k/mm/init.c497
1 files changed, 497 insertions, 0 deletions
diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c
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+++ b/arch/m68k/mm/init.c
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+/*
+ * linux/arch/m68k/mm/init.c
+ *
+ * Copyright (C) 1995 Hamish Macdonald
+ */
+
+#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>
+#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>
+
+extern void die_if_kernel(char *,struct pt_regs *,long);
+extern void init_kpointer_table(void);
+extern void show_net_buffers(void);
+
+/*
+ * BAD_PAGE is the page that is used for page faults when linux
+ * is out-of-memory. Older versions of linux just did a
+ * do_exit(), but using this instead means there is less risk
+ * for a process dying in kernel mode, possibly leaving an inode
+ * unused etc..
+ *
+ * BAD_PAGETABLE is the accompanying page-table: it is initialized
+ * to point to BAD_PAGE entries.
+ *
+ * ZERO_PAGE is a special page that is used for zero-initialized
+ * data and COW.
+ */
+static unsigned long empty_bad_page_table;
+
+pte_t *__bad_pagetable(void)
+{
+ memset((void *)empty_bad_page_table, 0, PAGE_SIZE);
+ return (pte_t *)empty_bad_page_table;
+}
+
+static unsigned long empty_bad_page;
+
+pte_t __bad_page(void)
+{
+ memset ((void *)empty_bad_page, 0, PAGE_SIZE);
+ return pte_mkdirty(mk_pte(empty_bad_page, PAGE_SHARED));
+}
+
+unsigned long empty_zero_page;
+
+void show_mem(void)
+{
+ unsigned long i;
+ int free = 0, total = 0, reserved = 0, nonshared = 0, shared = 0;
+
+ printk("\nMem-info:\n");
+ show_free_areas();
+ printk("Free swap: %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
+ i = max_mapnr;
+ while (i-- > 0) {
+ total++;
+ if (PageReserved(mem_map+i))
+ reserved++;
+ else if (!mem_map[i].count)
+ free++;
+ else if (mem_map[i].count == 1)
+ nonshared++;
+ else
+ shared += mem_map[i].count-1;
+ }
+ printk("%d pages of RAM\n",total);
+ printk("%d free pages\n",free);
+ printk("%d reserved pages\n",reserved);
+ printk("%d pages nonshared\n",nonshared);
+ printk("%d pages shared\n",shared);
+ show_buffers();
+#ifdef CONFIG_NET
+ show_net_buffers();
+#endif
+}
+
+#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
+
+pte_t *kernel_page_table (unsigned long *memavailp)
+{
+ pte_t *ptablep;
+
+ ptablep = (pte_t *)*memavailp;
+ *memavailp += PAGE_SIZE;
+
+ nocache_page ((unsigned long)ptablep);
+
+ return ptablep;
+}
+
+static unsigned long map_chunk (unsigned long addr,
+ unsigned long size,
+ unsigned long *memavailp)
+{
+#define ONEMEG (1024*1024)
+#define L3TREESIZE (256*1024)
+
+ static unsigned long mem_mapped = 0;
+ static unsigned long virtaddr = 0;
+ static pte_t *ktablep = NULL;
+ unsigned long *kpointerp;
+ unsigned long physaddr;
+ extern pte_t *kpt;
+ int pindex; /* index into pointer table */
+ pgd_t *page_dir = pgd_offset_k (virtaddr);
+
+ if (!pgd_present (*page_dir)) {
+ /* we need a new pointer table */
+ kpointerp = (unsigned long *) get_kpointer_table ();
+ pgd_set (page_dir, (pmd_t *) kpointerp);
+ memset (kpointerp, 0, PTRS_PER_PMD * sizeof (pmd_t));
+ }
+ else
+ kpointerp = (unsigned long *) pgd_page (*page_dir);
+
+ /*
+ * pindex is the offset into the pointer table for the
+ * descriptors for the current virtual address being mapped.
+ */
+ pindex = (virtaddr >> 18) & 0x7f;
+
+#ifdef DEBUG
+ printk ("mm=%ld, kernel_pg_dir=%p, kpointerp=%p, pindex=%d\n",
+ mem_mapped, kernel_pg_dir, kpointerp, pindex);
+#endif
+
+ /*
+ * if this is running on an '040, we already allocated a page
+ * table for the first 4M. The address is stored in kpt by
+ * arch/head.S
+ *
+ */
+ if (CPU_IS_040_OR_060 && mem_mapped == 0)
+ ktablep = kpt;
+
+ for (physaddr = addr;
+ physaddr < addr + size;
+ mem_mapped += L3TREESIZE, virtaddr += L3TREESIZE) {
+
+#ifdef DEBUG
+ printk ("pa=%#lx va=%#lx ", physaddr, virtaddr);
+#endif
+
+ if (pindex > 127 && mem_mapped >= 32*ONEMEG) {
+ /* we need a new pointer table every 32M */
+#ifdef DEBUG
+ printk ("[new pointer]");
+#endif
+
+ kpointerp = (unsigned long *)get_kpointer_table ();
+ pgd_set(pgd_offset_k(virtaddr), (pmd_t *)kpointerp);
+ pindex = 0;
+ }
+
+ if (CPU_IS_040_OR_060) {
+ int i;
+ unsigned long ktable;
+
+ /* Don't map the first 4 MB again. The pagetables
+ * for this range have already been initialized
+ * in boot/head.S. Otherwise the pages used for
+ * tables would be reinitialized to copyback mode.
+ */
+
+ if (mem_mapped < 4 * ONEMEG)
+ {
+#ifdef DEBUG
+ printk ("Already initialized\n");
+#endif
+ physaddr += L3TREESIZE;
+ pindex++;
+ continue;
+ }
+#ifdef DEBUG
+ printk ("[setup table]");
+#endif
+
+ /*
+ * 68040, use page tables pointed to by the
+ * kernel pointer table.
+ */
+
+ if ((pindex & 15) == 0) {
+ /* Need new page table every 4M on the '040 */
+#ifdef DEBUG
+ printk ("[new table]");
+#endif
+ ktablep = kernel_page_table (memavailp);
+ }
+
+ ktable = VTOP(ktablep);
+
+ /*
+ * initialize section of the page table mapping
+ * this 256K portion.
+ */
+ for (i = 0; i < 64; i++) {
+ pte_val(ktablep[i]) = physaddr | _PAGE_PRESENT
+ | _PAGE_CACHE040 | _PAGE_GLOBAL040
+ | _PAGE_ACCESSED;
+ physaddr += PAGE_SIZE;
+ }
+ ktablep += 64;
+
+ /*
+ * make the kernel pointer table point to the
+ * kernel page table. Each entries point to a
+ * 64 entry section of the page table.
+ */
+
+ kpointerp[pindex++] = ktable | _PAGE_TABLE | _PAGE_ACCESSED;
+ } else {
+ /*
+ * 68030, use early termination page descriptors.
+ * Each one points to 64 pages (256K).
+ */
+#ifdef DEBUG
+ printk ("[early term] ");
+#endif
+ if (virtaddr == 0UL) {
+ /* map the first 256K using a 64 entry
+ * 3rd level page table.
+ * UNMAP the first entry to trap
+ * zero page (NULL pointer) references
+ */
+ int i;
+ unsigned long *tbl;
+
+ tbl = (unsigned long *)get_kpointer_table();
+
+ kpointerp[pindex++] = VTOP(tbl) | _PAGE_TABLE |_PAGE_ACCESSED;
+
+ for (i = 0; i < 64; i++, physaddr += PAGE_SIZE)
+ tbl[i] = physaddr | _PAGE_PRESENT | _PAGE_ACCESSED;
+
+ /* unmap the zero page */
+ tbl[0] = 0;
+ } else {
+ /* not the first 256K */
+ kpointerp[pindex++] = physaddr | _PAGE_PRESENT | _PAGE_ACCESSED;
+#ifdef DEBUG
+ printk ("%lx=%lx ", VTOP(&kpointerp[pindex-1]),
+ kpointerp[pindex-1]);
+#endif
+ physaddr += 64 * PAGE_SIZE;
+ }
+ }
+#ifdef DEBUG
+ printk ("\n");
+#endif
+ }
+
+ return mem_mapped;
+}
+
+extern unsigned long free_area_init(unsigned long, unsigned long);
+
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
+
+/*
+ * paging_init() continues the virtual memory environment setup which
+ * was begun by the code in arch/head.S.
+ * The parameters are pointers to where to stick the starting and ending
+ * addresses of available kernel virtual memory.
+ */
+unsigned long paging_init(unsigned long start_mem, unsigned long end_mem)
+{
+ int chunk;
+ unsigned long mem_avail = 0;
+ /* pointer to page table for kernel stacks */
+ extern unsigned long availmem;
+
+#ifdef DEBUG
+ {
+ extern pte_t *kpt;
+ printk ("start of paging_init (%p, %p, %lx, %lx, %lx)\n",
+ kernel_pg_dir, kpt, availmem, start_mem, end_mem);
+ }
+#endif
+
+ init_kpointer_table();
+
+ /* 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 < boot_info.num_memory; chunk++) {
+ mem_avail = map_chunk (boot_info.memory[chunk].addr,
+ boot_info.memory[chunk].size,
+ &availmem);
+
+ }
+ flush_tlb_all();
+#ifdef DEBUG
+ printk ("memory available is %ldKB\n", mem_avail >> 10);
+#endif
+
+ /*
+ * virtual address after end of kernel
+ * "availmem" is setup by the code in head.S.
+ */
+ start_mem = availmem;
+
+#ifdef DEBUG
+ 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);
+
+#if 0
+ /*
+ * allocate the "swapper" page directory and
+ * record in task 0 (swapper) tss
+ */
+ swapper_pg_dir = (pgd_t *)get_kpointer_table();
+
+ init_mm.pgd = swapper_pg_dir;
+#endif
+
+ memset (swapper_pg_dir, 0, sizeof(pgd_t)*PTRS_PER_PGD);
+
+ /* setup CPU root pointer for swapper task */
+ task[0]->tss.crp[0] = 0x80000000 | _PAGE_TABLE;
+ task[0]->tss.crp[1] = VTOP (swapper_pg_dir);
+
+#ifdef DEBUG
+ printk ("task 0 pagedir at %p virt, %#lx phys\n",
+ swapper_pg_dir, task[0]->tss.crp[1]);
+#endif
+
+ if (CPU_IS_040_OR_060)
+ asm __volatile__ ("movel %0,%/d0\n\t"
+ ".long 0x4e7b0806" /* movec d0,urp */
+ : /* no outputs */
+ : "g" (task[0]->tss.crp[1])
+ : "d0");
+ else
+ asm __volatile__ ("movel %0,%/a0\n\t"
+ ".long 0xf0104c00" /* pmove %/a0@,%/crp */
+ : /* no outputs */
+ : "g" (task[0]->tss.crp)
+ : "a0");
+#ifdef DEBUG
+ printk ("set crp\n");
+#endif
+
+ /*
+ * Set up SFC/DFC registers (user data space)
+ */
+ set_fs (USER_DS);
+
+#ifdef DEBUG
+ printk ("before free_area_init\n");
+#endif
+
+ return free_area_init (start_mem, end_mem);
+}
+
+void mem_init(unsigned long start_mem, unsigned long end_mem)
+{
+ int codepages = 0;
+ int datapages = 0;
+ unsigned long tmp;
+ extern int _etext;
+
+ end_mem &= PAGE_MASK;
+ high_memory = (void *) end_mem;
+ max_mapnr = MAP_NR(end_mem);
+
+ start_mem = PAGE_ALIGN(start_mem);
+ while (start_mem < end_mem) {
+ clear_bit(PG_reserved, &mem_map[MAP_NR(start_mem)].flags);
+ start_mem += PAGE_SIZE;
+ }
+
+#ifdef CONFIG_ATARI
+
+ if (MACH_IS_ATARI) {
+
+ /* If the page with physical address 0 isn't the first kernel
+ * code page, it has to be reserved because the first 2 KB of
+ * ST-Ram can only be accessed from supervisor mode by
+ * hardware.
+ */
+
+ unsigned long virt0 = PTOV( 0 ), adr;
+ extern unsigned long rsvd_stram_beg, rsvd_stram_end;
+
+ if (virt0 != 0) {
+
+ set_bit(PG_reserved, &mem_map[MAP_NR(virt0)].flags);
+
+ /* Also, reserve all pages that have been marked by
+ * stram_alloc() (e.g. for the screen memory). (This may
+ * treat the first ST-Ram page a second time, but that
+ * doesn't hurt...) */
+
+ rsvd_stram_end += PAGE_SIZE - 1;
+ rsvd_stram_end &= PAGE_MASK;
+ rsvd_stram_beg &= PAGE_MASK;
+ for( adr = rsvd_stram_beg; adr < rsvd_stram_end; adr += PAGE_SIZE )
+ set_bit(PG_reserved, &mem_map[MAP_NR(adr)].flags);
+ }
+ }
+
+#endif
+
+ for (tmp = 0 ; tmp < end_mem ; tmp += PAGE_SIZE) {
+ if (VTOP (tmp) >= mach_max_dma_address)
+ clear_bit(PG_DMA, &mem_map[MAP_NR(tmp)].flags);
+ if (PageReserved(mem_map+MAP_NR(tmp))) {
+ if (tmp < (unsigned long)&_etext)
+ codepages++;
+ else
+ datapages++;
+ continue;
+ }
+ mem_map[MAP_NR(tmp)].count = 1;
+#ifdef CONFIG_BLK_DEV_INITRD
+ if (!initrd_start ||
+ (tmp < (initrd_start & PAGE_MASK) || tmp >= initrd_end))
+#endif
+ free_page(tmp);
+ }
+ printk("Memory: %luk/%luk available (%dk kernel code, %dk data)\n",
+ (unsigned long) nr_free_pages << (PAGE_SHIFT-10),
+ max_mapnr << (PAGE_SHIFT-10),
+ codepages << (PAGE_SHIFT-10),
+ datapages << (PAGE_SHIFT-10));
+}
+
+void si_meminfo(struct sysinfo *val)
+{
+ unsigned long i;
+
+ i = max_mapnr;
+ val->totalram = 0;
+ val->sharedram = 0;
+ val->freeram = nr_free_pages << PAGE_SHIFT;
+ val->bufferram = buffermem;
+ while (i-- > 0) {
+ if (PageReserved(mem_map+i))
+ continue;
+ val->totalram++;
+ if (!mem_map[i].count)
+ continue;
+ val->sharedram += mem_map[i].count-1;
+ }
+ val->totalram <<= PAGE_SHIFT;
+ val->sharedram <<= PAGE_SHIFT;
+ return;
+}
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