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acrn-kernel/arch/m68k/mm/motorola.c

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// 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_page_to_ram(page);
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(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.
*/
pgtable_pte_page_ctor(virt_to_page(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)
pgtable_pte_page_dtor(virt_to_page(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;
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;
if (addr > max_addr)
max_addr = addr;
i++;
}
m68k_memoffset = min_addr - PAGE_OFFSET;
m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6;
module_fixup(NULL, __start_fixup, __stop_fixup);
flush_icache();
high_memory = phys_to_virt(max_addr);
min_low_pfn = availmem >> PAGE_SHIFT;
max_pfn = max_low_pfn = max_addr >> PAGE_SHIFT;
/* 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);
}
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