/*
* linux/arch/m68k/mm/memory.c
*
* Copyright (C) 1995 Hamish Macdonald
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/traps.h>
#include <asm/machdep.h>
/* ++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 LIST_HEAD(ptable_list);
#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 char *)&PD_PAGE(dp)->index)
#define PTABLE_SIZE (PTRS_PER_PMD * sizeof(pmd_t))
void __init init_pointer_table(unsigned long ptable)
{
ptable_desc *dp;
unsigned long page = ptable & PAGE_MASK;
unsigned char mask = 1 << ((ptable - page)/PTABLE_SIZE);
dp = PD_PTABLE(page);
if (!(PD_MARKBITS(dp) & mask)) {
PD_MARKBITS(dp) = 0xff;
list_add(dp, &ptable_list);
}
PD_MARKBITS(dp) &= ~mask;
#ifdef DEBUG
printk("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp));
#endif
/* unreserve the page so it's possible to free that page */
PD_PAGE(dp)->flags &= ~(1 << PG_reserved);
init_page_count(PD_PAGE(dp));
return;
}
pmd_t *get_pointer_table (void)
{
ptable_desc *dp = ptable_list.next;
unsigned char mask = PD_MARKBITS (dp);
unsigned char tmp;
unsigned int 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;
flush_tlb_kernel_page(page);
nocache_page(page);
new = PD_PTABLE(page);
PD_MARKBITS(new) = 0xfe;
list_add_tail(new, dp);
return (pmd_t *)page;
}
for (tmp = 1, off = 0; (mask & tmp) == 0; tmp <<= 1, off += PTABLE_SIZE)
;
PD_MARKBITS(dp) = mask & ~tmp;
if (!PD_MARKBITS(dp)) {
/* move to end of list */
list_move_tail(dp, &ptable_list);
}
return (pmd_t *) (page_address(PD_PAGE(dp)) + off);
}
int free_pointer_table (pmd_t *ptable)
{
ptable_desc *dp;
unsigned long page = (unsigned long)ptable & PAGE_MASK;
unsigned char mask = 1 << (((unsigned long)ptable - page)/PTABLE_SIZE);
dp = PD_PTABLE(page);
if (PD_MARKBITS (dp) & mask)
panic ("table already free!");
PD_MARKBITS (dp) |= mask;
if (PD_MARKBITS(dp) == 0xff) {
/* all tables in page are free, free page */
list_del(dp);
cache_page((void *)page);
free_page (page);
return 1;
} else if (ptable_list.next != dp) {
/*
* move this descriptor to the front of the list, since
* it has one or more free tables.
*/
list_move(dp, &ptable_list);
}
return 0;
}
/* invalidate page in both caches */
static inline void clear040(unsigned long paddr)
{
asm volatile (
"nop\n\t"
".chip 68040\n\t"
"cinvp %%bc,(%0)\n\t"
".chip 68k"
: : "a" (paddr));
}
/* invalidate page in i-cache */
static inline void cleari040(unsigned long paddr)
{
asm volatile (
"nop\n\t"
".chip 68040\n\t"
"cinvp %%ic,(%0)\n\t"
".chip 68k"
: : "a" (paddr));
}
/* push page in both caches */
/* RZ: cpush %bc DOES invalidate %ic, regardless of DPI */
static inline void push040(unsigned long paddr)
{
asm volatile (
"nop\n\t"
".chip 68040\n\t"
"cpushp %%bc,(%0)\n\t"
".chip 68k"
: : "a" (paddr));
}
/* push and invalidate page in both caches, must disable ints
* to avoid invalidating valid data */
static inline void pushcl040(unsigned long paddr)
{
unsigned long flags;
local_irq_save(flags);
push040(paddr);
if (CPU_IS_060)
clear040(paddr);
local_irq_restore(flags);
}
/*
* 040: Hit every page containing an address in the range paddr..paddr+len-1.
* (Low order bits of the ea of a CINVP/CPUSHP are "don't care"s).
* Hit every page until there is a page or less to go. Hit the next page,
* and the one after that if the range hits it.
*/
/* ++roman: A little bit more care is required here: The CINVP instruction
* invalidates cache entries WITHOUT WRITING DIRTY DATA BACK! So the beginning
* and the end of the region must be treated differently if they are not
* exactly at the beginning or end of a page boundary. Else, maybe too much
* data becomes invalidated and thus lost forever. CPUSHP does what we need:
* it invalidates the page after pushing dirty data to memory. (Thanks to Jes
* for discovering the problem!)
*/
/* ... but on the '060, CPUSH doesn't invalidate (for us, since we have set
* the DPI bit in the CACR; would it cause problems with temporarily changing
* this?). So we have to push first and then additionally to invalidate.
*/
/*
* cache_clear() semantics: Clear any cache entries for the area in question,
* without writing back dirty entries first. This is useful if the data will
* be overwritten anyway, e.g. by DMA to memory. The range is defined by a
* _physical_ address.
*/
void cache_clear (unsigned long paddr, int len)
{
if (CPU_IS_040_OR_060) {
int tmp;
/*
* We need special treatment for the first page, in case it
* is not page-aligned. Page align the addresses to work
* around bug I17 in the 68060.
*/
if ((tmp = -paddr & (PAGE_SIZE - 1))) {
pushcl040(paddr & PAGE_MASK);
if ((len -= tmp) <= 0)
return;
paddr += tmp;
}
tmp = PAGE_SIZE;
paddr &= PAGE_MASK;
while ((len -= tmp) >= 0) {
clear040(paddr);
paddr += tmp;
}
if ((len += tmp))
/* a page boundary gets crossed at the end */
pushcl040(paddr);
}
else /* 68030 or 68020 */
asm volatile ("movec %/cacr,%/d0\n\t"
"oriw %0,%/d0\n\t"
"movec %/d0,%/cacr"
: : "i" (FLUSH_I_AND_D)
: "d0");
#ifdef CONFIG_M68K_L2_CACHE
if(mach_l2_flush)
mach_l2_flush(0);
#endif
}
EXPORT_SYMBOL(cache_clear);
/*
* cache_push() semantics: Write back any dirty cache data in the given area,
* and invalidate the range in the instruction cache. It needs not (but may)
* invalidate those entries also in the data cache. The range is defined by a
* _physical_ address.
*/
void cache_push (unsigned long paddr, int len)
{
if (CPU_IS_040_OR_060) {
int tmp = PAGE_SIZE;
/*
* on 68040 or 68060, push cache lines for pages in the range;
* on the '040 this also invalidates the pushed lines, but not on
* the '060!
*/
len += paddr & (PAGE_SIZE - 1);
/*
* Work around bug I17 in the 68060 affecting some instruction
* lines not being invalidated properly.
*/
paddr &= PAGE_MASK;
do {
push040(paddr);
paddr += tmp;
} while ((len -= tmp) > 0);
}
/*
* 68030/68020 have no writeback cache. On the other hand,
* cache_push is actually a superset of cache_clear (the lines
* get written back and invalidated), so we should make sure
* to perform the corresponding actions. After all, this is getting
* called in places where we've just loaded code, or whatever, so
* flushing the icache is appropriate; flushing the dcache shouldn't
* be required.
*/
else /* 68030 or 68020 */
asm volatile ("movec %/cacr,%/d0\n\t"
"oriw %0,%/d0\n\t"
"movec %/d0,%/cacr"
: : "i" (FLUSH_I)
: "d0");
#ifdef CONFIG_M68K_L2_CACHE
if(mach_l2_flush)
mach_l2_flush(1);
#endif
}
EXPORT_SYMBOL(cache_push);
