Commit 5ad272ab authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Geert Uytterhoeven
Browse files

m68k: mm: Move the pointer table allocator to motorola.c 



Only the Motorola MMU makes use of this allocator, it is a waste of
.text to include it for Sun3/ColdFire. Also, this is going to avoid
build issues when we're going to make it more Motorola specific.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Acked-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
Tested-by: default avatarMichael Schmitz <schmitzmic@gmail.com>
Tested-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
Link: https://lore.kernel.org/r/20200131125403.654652162@infradead.org


Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
parent 13076a29

arch/m68k/mm/memory.c

+0 −102
Original line number Diff line number Diff line
@@ -22,108 +22,6 @@ 
#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;

	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;

}



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;



		mmu_page_ctor(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);

		mmu_page_dtor((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)

{

arch/m68k/mm/motorola.c

+102 −0
Original line number Diff line number Diff line
@@ -67,6 +67,108 @@ 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 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;

	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;

}



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;



		mmu_page_ctor(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);

		mmu_page_dtor((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;

}



/* size of memory already mapped in head.S */

extern __initdata unsigned long m68k_init_mapped_size;

CRA Git | Maintained and supported by SUSTech CRA and CCSE