arch/m68k/mm/memory.c - kernel/skids - Git at Google

 /*
  *  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/init.h>
 #include <linux/pagemap.h>
 #include <linux/gfp.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);
	/*
	* 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/init.h>
	#include <linux/pagemap.h>
	#include <linux/gfp.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);