1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/arch/m68k/mm/sun3mmu.c 4 * 5 * Implementations of mm routines specific to the sun3 MMU. 6 * 7 * Moved here 8/20/1999 Sam Creasey 8 * 9 */ 10 11 #include <linux/signal.h> 12 #include <linux/sched.h> 13 #include <linux/mm.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> 20 21 #include <asm/setup.h> 22 #include <linux/uaccess.h> 23 #include <asm/page.h> 24 #include <asm/machdep.h> 25 #include <asm/io.h> 26 27 #include "../sun3/sun3.h" 28 29 const char bad_pmd_string[] = "Bad pmd in pte_alloc: %08lx\n"; 30 31 extern unsigned long num_pages; 32 33 /* For the sun3 we try to follow the i386 paging_init() more closely */ 34 /* start_mem and end_mem have PAGE_OFFSET added already */ 35 /* now sets up tables using sun3 PTEs rather than i386 as before. --m */ paging_init(void)36 void __init paging_init(void) 37 { 38 pgd_t * pg_dir; 39 pte_t * pg_table; 40 int i; 41 unsigned long address; 42 unsigned long next_pgtable; 43 unsigned long bootmem_end; 44 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, }; 45 unsigned long size; 46 47 empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE); 48 if (!empty_zero_page) 49 panic("%s: Failed to allocate %lu bytes align=0x%lx\n", 50 __func__, PAGE_SIZE, PAGE_SIZE); 51 52 address = PAGE_OFFSET; 53 pg_dir = swapper_pg_dir; 54 memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir)); 55 memset (kernel_pg_dir, 0, sizeof (kernel_pg_dir)); 56 57 size = num_pages * sizeof(pte_t); 58 size = (size + PAGE_SIZE) & ~(PAGE_SIZE-1); 59 60 next_pgtable = (unsigned long)memblock_alloc(size, PAGE_SIZE); 61 if (!next_pgtable) 62 panic("%s: Failed to allocate %lu bytes align=0x%lx\n", 63 __func__, size, PAGE_SIZE); 64 bootmem_end = (next_pgtable + size + PAGE_SIZE) & PAGE_MASK; 65 66 /* Map whole memory from PAGE_OFFSET (0x0E000000) */ 67 pg_dir += PAGE_OFFSET >> PGDIR_SHIFT; 68 69 while (address < (unsigned long)high_memory) { 70 pg_table = (pte_t *) __pa (next_pgtable); 71 next_pgtable += PTRS_PER_PTE * sizeof (pte_t); 72 pgd_val(*pg_dir) = (unsigned long) pg_table; 73 pg_dir++; 74 75 /* now change pg_table to kernel virtual addresses */ 76 pg_table = (pte_t *) __va ((unsigned long) pg_table); 77 for (i=0; i<PTRS_PER_PTE; ++i, ++pg_table) { 78 pte_t pte = pfn_pte(virt_to_pfn((void *)address), PAGE_INIT); 79 if (address >= (unsigned long)high_memory) 80 pte_val (pte) = 0; 81 set_pte (pg_table, pte); 82 address += PAGE_SIZE; 83 } 84 } 85 86 mmu_emu_init(bootmem_end); 87 88 current->mm = NULL; 89 90 /* memory sizing is a hack stolen from motorola.c.. hope it works for us */ 91 max_zone_pfn[ZONE_DMA] = ((unsigned long)high_memory) >> PAGE_SHIFT; 92 93 /* I really wish I knew why the following change made things better... -- Sam */ 94 free_area_init(max_zone_pfn); 95 96 97 } 98 99 static const pgprot_t protection_map[16] = { 100 [VM_NONE] = PAGE_NONE, 101 [VM_READ] = PAGE_READONLY, 102 [VM_WRITE] = PAGE_COPY, 103 [VM_WRITE | VM_READ] = PAGE_COPY, 104 [VM_EXEC] = PAGE_READONLY, 105 [VM_EXEC | VM_READ] = PAGE_READONLY, 106 [VM_EXEC | VM_WRITE] = PAGE_COPY, 107 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY, 108 [VM_SHARED] = PAGE_NONE, 109 [VM_SHARED | VM_READ] = PAGE_READONLY, 110 [VM_SHARED | VM_WRITE] = PAGE_SHARED, 111 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED, 112 [VM_SHARED | VM_EXEC] = PAGE_READONLY, 113 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY, 114 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED, 115 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED 116 }; 117 DECLARE_VM_GET_PAGE_PROT 118