1 // SPDX-License-Identifier: GPL-2.0
3 * linux/arch/m68k/mm/sun3mmu.c
5 * Implementations of mm routines specific to the sun3 MMU.
7 * Moved here 8/20/1999 Sam Creasey
11 #include <linux/signal.h>
12 #include <linux/sched.h>
14 #include <linux/swap.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 #include <linux/init.h>
19 #include <linux/memblock.h>
21 #include <asm/setup.h>
22 #include <linux/uaccess.h>
24 #include <asm/pgtable.h>
25 #include <asm/machdep.h>
28 extern void mmu_emu_init (unsigned long bootmem_end);
30 const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n";
32 extern unsigned long num_pages;
34 /* For the sun3 we try to follow the i386 paging_init() more closely */
35 /* start_mem and end_mem have PAGE_OFFSET added already */
36 /* now sets up tables using sun3 PTEs rather than i386 as before. --m */
37 void __init paging_init(void)
42 unsigned long address;
43 unsigned long next_pgtable;
44 unsigned long bootmem_end;
45 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
48 empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
50 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
51 __func__, PAGE_SIZE, PAGE_SIZE);
53 address = PAGE_OFFSET;
54 pg_dir = swapper_pg_dir;
55 memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir));
56 memset (kernel_pg_dir, 0, sizeof (kernel_pg_dir));
58 size = num_pages * sizeof(pte_t);
59 size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1);
61 next_pgtable = (unsigned long)memblock_alloc(size, PAGE_SIZE);
63 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
64 __func__, size, PAGE_SIZE);
65 bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK;
67 /* Map whole memory from PAGE_OFFSET (0x0E000000) */
68 pg_dir += PAGE_OFFSET >> PGDIR_SHIFT;
70 while (address < (unsigned long)high_memory) {
71 pg_table = (pte_t *) __pa (next_pgtable);
72 next_pgtable += PTRS_PER_PTE * sizeof (pte_t);
73 pgd_val(*pg_dir) = (unsigned long) pg_table;
76 /* now change pg_table to kernel virtual addresses */
77 pg_table = (pte_t *) __va ((unsigned long) pg_table);
78 for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) {
79 pte_t pte = pfn_pte(virt_to_pfn(address), PAGE_INIT);
80 if (address >= (unsigned long)high_memory)
82 set_pte (pg_table, pte);
87 mmu_emu_init(bootmem_end);
91 /* memory sizing is a hack stolen from motorola.c.. hope it works for us */
92 zones_size[ZONE_DMA] = ((unsigned long)high_memory - PAGE_OFFSET) >> PAGE_SHIFT;
94 /* I really wish I knew why the following change made things better... -- Sam */
95 /* free_area_init(zones_size); */
96 free_area_init_node(0, zones_size,
97 (__pa(PAGE_OFFSET) >> PAGE_SHIFT) + 1, NULL);