// SPDX-License-Identifier: GPL-2.0 /* * linux/arch/m68k/mm/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/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/memblock.h> #include <linux/gfp.h> #include <asm/setup.h> #include <linux/uaccess.h> #include <asm/page.h> #include <asm/pgalloc.h> #include <asm/machdep.h> #include <asm/io.h> #ifdef CONFIG_ATARI #include <asm/atari_stram.h> #endif #include <asm/sections.h> #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 /* Prior to calling these routines, the page should have been flushed * from both the cache and ATC, or the CPU might not notice that the * cache setting for the page has been changed. -jskov */ static inline void nocache_page(void *vaddr) { unsigned long addr = (unsigned long)vaddr; if (CPU_IS_040_OR_060) { pte_t *ptep = virt_to_kpte(addr); *ptep = pte_mknocache(*ptep); } } static inline void cache_page(void *vaddr) { unsigned long addr = (unsigned long)vaddr; if (CPU_IS_040_OR_060) { pte_t *ptep = virt_to_kpte(addr); *ptep = pte_mkcache(*ptep); } } /* * Motorola 680x0 user's manual recommends using uncached memory for address * translation tables. * * Seeing how the MMU can be external on (some of) these chips, that seems like * a very important recommendation to follow. Provide some helpers to combat * 'variation' amongst the users of this. */ void mmu_page_ctor(void *page) { __flush_pages_to_ram(page, 1); flush_tlb_kernel_page(page); nocache_page(page); } void mmu_page_dtor(void *page) { cache_page(page); } /* ++andreas: {get,free}_pointer_table rewritten to use unused fields from struct page instead of separately kmalloced struct. Stolen from arch/sparc/mm/srmmu.c ... */ typedef struct list_head ptable_desc; static struct list_head ptable_list[2] = { LIST_HEAD_INIT(ptable_list[0]), LIST_HEAD_INIT(ptable_list[1]), }; #define PD_PTABLE(page) ((ptable_desc *)&(virt_to_page((void *)(page))->lru)) #define PD_PAGE(ptable) (list_entry(ptable, struct page, lru)) #define PD_MARKBITS(dp) (*(unsigned int *)&PD_PAGE(dp)->index) static const int ptable_shift[2] = { 7+2, /* PGD, PMD */ 6+2, /* PTE */ }; #define ptable_size(type) (1U << ptable_shift[type]) #define ptable_mask(type) ((1U << (PAGE_SIZE / ptable_size(type))) - 1) void __init init_pointer_table(void *table, int type) { ptable_desc *dp; unsigned long ptable = (unsigned long)table; unsigned long page = ptable & PAGE_MASK; unsigned int mask = 1U << ((ptable - page)/ptable_size(type)); dp = PD_PTABLE(page); if (!(PD_MARKBITS(dp) & mask)) { PD_MARKBITS(dp) = ptable_mask(type); list_add(dp, &ptable_list[type]); } PD_MARKBITS(dp) &= ~mask; pr_debug("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp)); /* unreserve the page so it's possible to free that page */ __ClearPageReserved(PD_PAGE(dp)); init_page_count(PD_PAGE(dp)); return; } void *get_pointer_table(int type) { ptable_desc *dp = ptable_list[type].next; unsigned int mask = list_empty(&ptable_list[type]) ? 0 : PD_MARKBITS(dp); unsigned int tmp, off; /* * For a pointer table for a user process address space, a * table is taken from a page allocated for the purpose. Each * page can hold 8 pointer tables. The page is remapped in * virtual address space to be noncacheable. */ if (mask == 0) { void *page; ptable_desc *new; if (!(page = (void *)get_zeroed_page(GFP_KERNEL))) return NULL; if (type == TABLE_PTE) { /* * m68k doesn't have SPLIT_PTE_PTLOCKS for not having * SMP. */ pagetable_pte_ctor(virt_to_ptdesc(page)); } mmu_page_ctor(page); new = PD_PTABLE(page); PD_MARKBITS(new) = ptable_mask(type) - 1; list_add_tail(new, dp); return (pmd_t *)page; } for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += ptable_size(type)) ; PD_MARKBITS(dp) = mask & ~tmp; if (!PD_MARKBITS(dp)) { /* move to end of list */ list_move_tail(dp, &ptable_list[type]); } return page_address(PD_PAGE(dp)) + off; } int free_pointer_table(void *table, int type) { ptable_desc *dp; unsigned long ptable = (unsigned long)table; unsigned long page = ptable & PAGE_MASK; unsigned int mask = 1U << ((ptable - page)/ptable_size(type)); dp = PD_PTABLE(page); if (PD_MARKBITS (dp) & mask) panic ("table already free!"); PD_MARKBITS (dp) |= mask; if (PD_MARKBITS(dp) == ptable_mask(type)) { /* all tables in page are free, free page */ list_del(dp); mmu_page_dtor((void *)page); if (type == TABLE_PTE) pagetable_pte_dtor(virt_to_ptdesc((void *)page)); free_page (page); return 1; } else if (ptable_list[type].next != dp) { /* * move this descriptor to the front of the list, since * it has one or more free tables. */ list_move(dp, &ptable_list[type]); } return 0; } /* size of memory already mapped in head.S */ extern __initdata unsigned long m68k_init_mapped_size; extern unsigned long availmem; static pte_t *last_pte_table __initdata = NULL; static pte_t * __init kernel_page_table(void) { pte_t *pte_table = last_pte_table; if (PAGE_ALIGNED(last_pte_table)) { pte_table = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); if (!pte_table) { panic("%s: Failed to allocate %lu bytes align=%lx\n", __func__, PAGE_SIZE, PAGE_SIZE); } clear_page(pte_table); mmu_page_ctor(pte_table); last_pte_table = pte_table; } last_pte_table += PTRS_PER_PTE; return pte_table; } static pmd_t *last_pmd_table __initdata = NULL; static pmd_t * __init kernel_ptr_table(void) { if (!last_pmd_table) { 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++) { pud_t *pud = (pud_t *)(&kernel_pg_dir[i]); if (!pud_present(*pud)) continue; pmd = pgd_page_vaddr(kernel_pg_dir[i]); if (pmd > last) last = pmd; } last_pmd_table = (pmd_t *)last; #ifdef DEBUG printk("kernel_ptr_init: %p\n", last_pmd_table); #endif } last_pmd_table += PTRS_PER_PMD; if (PAGE_ALIGNED(last_pmd_table)) { last_pmd_table = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); if (!last_pmd_table) panic("%s: Failed to allocate %lu bytes align=%lx\n", __func__, PAGE_SIZE, PAGE_SIZE); clear_page(last_pmd_table); mmu_page_ctor(last_pmd_table); } return last_pmd_table; } static void __init map_node(int node) { unsigned long physaddr, virtaddr, size; pgd_t *pgd_dir; p4d_t *p4d_dir; pud_t *pud_dir; pmd_t *pmd_dir; pte_t *pte_dir; size = m68k_memory[node].size; physaddr = m68k_memory[node].addr; virtaddr = (unsigned long)phys_to_virt(physaddr); physaddr |= 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 & (PMD_SIZE-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 & (PGDIR_SIZE-1)) && size >= PGDIR_SIZE) { #ifdef DEBUG printk ("[very early term]"); #endif pgd_val(*pgd_dir) = physaddr; size -= PGDIR_SIZE; virtaddr += PGDIR_SIZE; physaddr += PGDIR_SIZE; continue; } } p4d_dir = p4d_offset(pgd_dir, virtaddr); pud_dir = pud_offset(p4d_dir, virtaddr); if (!pud_present(*pud_dir)) { pmd_dir = kernel_ptr_table(); #ifdef DEBUG printk ("[new pointer %p]", pmd_dir); #endif pud_set(pud_dir, pmd_dir); } else pmd_dir = pmd_offset(pud_dir, virtaddr); if (CPU_IS_020_OR_030) { if (virtaddr) { #ifdef DEBUG printk ("[early term]"); #endif pmd_val(*pmd_dir) = physaddr; physaddr += PMD_SIZE; } else { int i; #ifdef DEBUG printk ("[zero map]"); #endif pte_dir = kernel_page_table(); pmd_set(pmd_dir, pte_dir); pte_val(*pte_dir++) = 0; physaddr += PAGE_SIZE; for (i = 1; i < PTRS_PER_PTE; physaddr += PAGE_SIZE, i++) pte_val(*pte_dir++) = physaddr; } size -= PMD_SIZE; virtaddr += PMD_SIZE; } 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 } /* * Alternate definitions that are compile time constants, for * initializing protection_map. The cachebits are fixed later. */ #define PAGE_NONE_C __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED) #define PAGE_SHARED_C __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED) #define PAGE_COPY_C __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED) #define PAGE_READONLY_C __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED) static pgprot_t protection_map[16] __ro_after_init = { [VM_NONE] = PAGE_NONE_C, [VM_READ] = PAGE_READONLY_C, [VM_WRITE] = PAGE_COPY_C, [VM_WRITE | VM_READ] = PAGE_COPY_C, [VM_EXEC] = PAGE_READONLY_C, [VM_EXEC | VM_READ] = PAGE_READONLY_C, [VM_EXEC | VM_WRITE] = PAGE_COPY_C, [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_C, [VM_SHARED] = PAGE_NONE_C, [VM_SHARED | VM_READ] = PAGE_READONLY_C, [VM_SHARED | VM_WRITE] = PAGE_SHARED_C, [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED_C, [VM_SHARED | VM_EXEC] = PAGE_READONLY_C, [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_C, [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_C, [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_C }; DECLARE_VM_GET_PAGE_PROT /* * paging_init() continues the virtual memory environment setup which * was begun by the code in arch/head.S. */ void __init paging_init(void) { unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, }; unsigned long min_addr, max_addr; unsigned long addr; int i; #ifdef DEBUG printk ("start of paging_init (%p, %lx)\n", kernel_pg_dir, availmem); #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; } min_addr = m68k_memory[0].addr; max_addr = min_addr + m68k_memory[0].size - 1; memblock_add_node(m68k_memory[0].addr, m68k_memory[0].size, 0, MEMBLOCK_NONE); for (i = 1; i < m68k_num_memory;) { if (m68k_memory[i].addr < min_addr) { printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n", m68k_memory[i].addr, m68k_memory[i].size); printk("Fix your bootloader or use a memfile to make use of this area!\n"); m68k_num_memory--; memmove(m68k_memory + i, m68k_memory + i + 1, (m68k_num_memory - i) * sizeof(struct m68k_mem_info)); continue; } memblock_add_node(m68k_memory[i].addr, m68k_memory[i].size, i, MEMBLOCK_NONE); addr = m68k_memory[i].addr + m68k_memory[i].size - 1; if (addr > max_addr) max_addr = addr; i++; } m68k_memoffset = min_addr - PAGE_OFFSET; m68k_virt_to_node_shift = fls(max_addr - min_addr) - 6; module_fixup(NULL, __start_fixup, __stop_fixup); flush_icache(); high_memory = phys_to_virt(max_addr) + 1; min_low_pfn = availmem >> PAGE_SHIFT; max_pfn = max_low_pfn = (max_addr >> PAGE_SHIFT) + 1; /* Reserve kernel text/data/bss and the memory allocated in head.S */ memblock_reserve(m68k_memory[0].addr, availmem - m68k_memory[0].addr); /* * Map the physical memory available into the kernel virtual * address space. Make sure memblock will not try to allocate * pages beyond the memory we already mapped in head.S */ memblock_set_bottom_up(true); for (i = 0; i < m68k_num_memory; i++) { m68k_setup_node(i); map_node(i); } flush_tlb_all(); early_memtest(min_addr, max_addr); /* * initialize the bad page table and bad page to point * to a couple of allocated pages */ empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE); if (!empty_zero_page) panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, PAGE_SIZE, PAGE_SIZE); /* * Set up SFC/DFC registers */ set_fc(USER_DATA); #ifdef DEBUG printk ("before free_area_init\n"); #endif for (i = 0; i < m68k_num_memory; i++) if (node_present_pages(i)) node_set_state(i, N_NORMAL_MEMORY); max_zone_pfn[ZONE_DMA] = memblock_end_of_DRAM(); free_area_init(max_zone_pfn); }