arch/m68k/atari/stram.c - third_party/linux - Git at Google

 /*
  * arch/m68k/atari/stram.c: Functions for ST-RAM allocations
  *
  * Copyright 1994-97 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file COPYING in the main directory of this archive
  * for more details.
  */

 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/kdev_t.h>
 #include <linux/major.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/pagemap.h>
 #include <linux/bootmem.h>
 #include <linux/mount.h>
 #include <linux/blkdev.h>
 #include <linux/module.h>

 #include <asm/setup.h>
 #include <asm/machdep.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include <asm/atarihw.h>
 #include <asm/atari_stram.h>
 #include <asm/io.h>

 #undef DEBUG

 #ifdef DEBUG
 #define	DPRINTK(fmt,args...) printk( fmt, ##args )
 #else
 #define DPRINTK(fmt,args...)
 #endif

 #if defined(CONFIG_PROC_FS) && defined(CONFIG_STRAM_PROC)
 /* abbrev for the && above... */
 #define DO_PROC
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #endif

 /*
  * ++roman:
  *
  * New version of ST-Ram buffer allocation. Instead of using the
  * 1 MB - 4 KB that remain when the ST-Ram chunk starts at $1000
  * (1 MB granularity!), such buffers are reserved like this:
  *
  *  - If the kernel resides in ST-Ram anyway, we can take the buffer
  *    from behind the current kernel data space the normal way
  *    (incrementing start_mem).
  *
  *  - If the kernel is in TT-Ram, stram_init() initializes start and
  *    end of the available region. Buffers are allocated from there
  *    and mem_init() later marks the such used pages as reserved.
  *    Since each TT-Ram chunk is at least 4 MB in size, I hope there
  *    won't be an overrun of the ST-Ram region by normal kernel data
  *    space.
  *
  * For that, ST-Ram may only be allocated while kernel initialization
  * is going on, or exactly: before mem_init() is called. There is also
  * no provision now for freeing ST-Ram buffers. It seems that isn't
  * really needed.
  *
  */

 /* Start and end (virtual) of ST-RAM */
 static void *stram_start, *stram_end;

 /* set after memory_init() executed and allocations via start_mem aren't
  * possible anymore */
 static int mem_init_done;

 /* set if kernel is in ST-RAM */
 static int kernel_in_stram;

 typedef struct stram_block {
 	struct stram_block *next;
 	void *start;
 	unsigned long size;
 	unsigned flags;
 	const char *owner;
 } BLOCK;

 /* values for flags field */
 #define BLOCK_FREE	0x01	/* free structure in the BLOCKs pool */
 #define BLOCK_KMALLOCED	0x02	/* structure allocated by kmalloc() */
 #define BLOCK_GFP	0x08	/* block allocated with __get_dma_pages() */

 /* list of allocated blocks */
 static BLOCK *alloc_list;

 /* We can't always use kmalloc() to allocate BLOCK structures, since
  * stram_alloc() can be called rather early. So we need some pool of
  * statically allocated structures. 20 of them is more than enough, so in most
  * cases we never should need to call kmalloc(). */
 #define N_STATIC_BLOCKS	20
 static BLOCK static_blocks[N_STATIC_BLOCKS];

 /***************************** Prototypes *****************************/

 static BLOCK *add_region( void *addr, unsigned long size );
 static BLOCK *find_region( void *addr );
 static int remove_region( BLOCK *block );

 /************************* End of Prototypes **************************/


 /* ------------------------------------------------------------------------ */
 /*							   Public Interface								*/
 /* ------------------------------------------------------------------------ */

 /*
  * This init function is called very early by atari/config.c
  * It initializes some internal variables needed for stram_alloc()
  */
 void __init atari_stram_init(void)
 {
 	int i;

 	/* initialize static blocks */
 	for( i = 0; i < N_STATIC_BLOCKS; ++i )
 		static_blocks[i].flags = BLOCK_FREE;

 	/* determine whether kernel code resides in ST-RAM (then ST-RAM is the
 	 * first memory block at virtual 0x0) */
 	stram_start = phys_to_virt(0);
 	kernel_in_stram = (stram_start == 0);

 	for( i = 0; i < m68k_num_memory; ++i ) {
 		if (m68k_memory[i].addr == 0) {
 			/* skip first 2kB or page (supervisor-only!) */
 			stram_end = stram_start + m68k_memory[i].size;
 			return;
 		}
 	}
 	/* Should never come here! (There is always ST-Ram!) */
 	panic( "atari_stram_init: no ST-RAM found!" );
 }


 /*
  * This function is called from setup_arch() to reserve the pages needed for
  * ST-RAM management.
  */
 void __init atari_stram_reserve_pages(void *start_mem)
 {
 	/* always reserve first page of ST-RAM, the first 2 kB are
 	 * supervisor-only! */
 	if (!kernel_in_stram)
 		reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT);

 }

 void atari_stram_mem_init_hook (void)
 {
 	mem_init_done = 1;
 }


 /*
  * This is main public interface: somehow allocate a ST-RAM block
  *
  *  - If we're before mem_init(), we have to make a static allocation. The
  *    region is taken in the kernel data area (if the kernel is in ST-RAM) or
  *    from the start of ST-RAM (if the kernel is in TT-RAM) and added to the
  *    rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel
  *    address space in the latter case.
  *
  *  - If mem_init() already has been called, try with __get_dma_pages().
  *    This has the disadvantage that it's very hard to get more than 1 page,
  *    and it is likely to fail :-(
  *
  */
 void *atari_stram_alloc(long size, const char *owner)
 {
 	void *addr = NULL;
 	BLOCK *block;
 	int flags;

 	DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner);

 	if (!mem_init_done)
 		return alloc_bootmem_low(size);
 	else {
 		/* After mem_init(): can only resort to __get_dma_pages() */
 		addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size));
 		flags = BLOCK_GFP;
 		DPRINTK( "atari_stram_alloc: after mem_init, "
 				 "get_pages=%p\n", addr );
 	}

 	if (addr) {
 		if (!(block = add_region( addr, size ))) {
 			/* out of memory for BLOCK structure :-( */
 			DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- "
 					 "freeing again\n" );
 			free_pages((unsigned long)addr, get_order(size));
 			return( NULL );
 		}
 		block->owner = owner;
 		block->flags |= flags;
 	}
 	return( addr );
 }
 EXPORT_SYMBOL(atari_stram_alloc);

 void atari_stram_free( void *addr )

 {
 	BLOCK *block;

 	DPRINTK( "atari_stram_free(addr=%p)\n", addr );

 	if (!(block = find_region( addr ))) {
 		printk( KERN_ERR "Attempt to free non-allocated ST-RAM block at %p "
 				"from %p\n", addr, __builtin_return_address(0) );
 		return;
 	}
 	DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, "
 			 "flags=%02x\n", block, block->size, block->owner, block->flags );

 	if (!(block->flags & BLOCK_GFP))
 		goto fail;

 	DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n",
 		get_order(block->size));
 	free_pages((unsigned long)addr, get_order(block->size));
 	remove_region( block );
 	return;

   fail:
 	printk( KERN_ERR "atari_stram_free: cannot free block at %p "
 			"(called from %p)\n", addr, __builtin_return_address(0) );
 }
 EXPORT_SYMBOL(atari_stram_free);


 /* ------------------------------------------------------------------------ */
 /*							  Region Management								*/
 /* ------------------------------------------------------------------------ */


 /* insert a region into the alloced list (sorted) */
 static BLOCK *add_region( void *addr, unsigned long size )
 {
 	BLOCK **p, *n = NULL;
 	int i;

 	for( i = 0; i < N_STATIC_BLOCKS; ++i ) {
 		if (static_blocks[i].flags & BLOCK_FREE) {
 			n = &static_blocks[i];
 			n->flags = 0;
 			break;
 		}
 	}
 	if (!n && mem_init_done) {
 		/* if statics block pool exhausted and we can call kmalloc() already
 		 * (after mem_init()), try that */
 		n = kmalloc( sizeof(BLOCK), GFP_KERNEL );
 		if (n)
 			n->flags = BLOCK_KMALLOCED;
 	}
 	if (!n) {
 		printk( KERN_ERR "Out of memory for ST-RAM descriptor blocks\n" );
 		return( NULL );
 	}
 	n->start = addr;
 	n->size  = size;

 	for( p = &alloc_list; *p; p = &((*p)->next) )
 		if ((*p)->start > addr) break;
 	n->next = *p;
 	*p = n;

 	return( n );
 }


 /* find a region (by start addr) in the alloced list */
 static BLOCK *find_region( void *addr )
 {
 	BLOCK *p;

 	for( p = alloc_list; p; p = p->next ) {
 		if (p->start == addr)
 			return( p );
 		if (p->start > addr)
 			break;
 	}
 	return( NULL );
 }


 /* remove a block from the alloced list */
 static int remove_region( BLOCK *block )
 {
 	BLOCK **p;

 	for( p = &alloc_list; *p; p = &((*p)->next) )
 		if (*p == block) break;
 	if (!*p)
 		return( 0 );

 	*p = block->next;
 	if (block->flags & BLOCK_KMALLOCED)
 		kfree( block );
 	else
 		block->flags |= BLOCK_FREE;
 	return( 1 );
 }


 /* ------------------------------------------------------------------------ */
 /*						 /proc statistics file stuff						*/
 /* ------------------------------------------------------------------------ */

 #ifdef DO_PROC

 #define	PRINT_PROC(fmt,args...) seq_printf( m, fmt, ##args )

 static int stram_proc_show(struct seq_file *m, void *v)
 {
 	BLOCK *p;

 	PRINT_PROC("Total ST-RAM:      %8u kB\n",
 			   (stram_end - stram_start) >> 10);
 	PRINT_PROC( "Allocated regions:\n" );
 	for( p = alloc_list; p; p = p->next ) {
 		PRINT_PROC("0x%08lx-0x%08lx: %s (",
 			   virt_to_phys(p->start),
 			   virt_to_phys(p->start+p->size-1),
 			   p->owner);
 		if (p->flags & BLOCK_GFP)
 			PRINT_PROC( "page-alloced)\n" );
 		else
 			PRINT_PROC( "??)\n" );
 	}

 	return 0;
 }

 static int stram_proc_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, stram_proc_show, NULL);
 }

 static const struct file_operations stram_proc_fops = {
 	.open		= stram_proc_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };

 static int __init proc_stram_init(void)
 {
 	proc_create("stram", 0, NULL, &stram_proc_fops);
 	return 0;
 }
 module_init(proc_stram_init);
 #endif


 /*
  * Local variables:
  *  c-indent-level: 4
  *  tab-width: 4
  * End:
  */
	/*
	* arch/m68k/atari/stram.c: Functions for ST-RAM allocations
	*
	* Copyright 1994-97 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
	*
	* This file is subject to the terms and conditions of the GNU General Public
	* License. See the file COPYING in the main directory of this archive
	* for more details.
	*/

	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/kdev_t.h>
	#include <linux/major.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/vmalloc.h>
	#include <linux/pagemap.h>
	#include <linux/bootmem.h>
	#include <linux/mount.h>
	#include <linux/blkdev.h>
	#include <linux/module.h>

	#include <asm/setup.h>
	#include <asm/machdep.h>
	#include <asm/page.h>
	#include <asm/pgtable.h>
	#include <asm/atarihw.h>
	#include <asm/atari_stram.h>
	#include <asm/io.h>

	#undef DEBUG

	#ifdef DEBUG
	#define DPRINTK(fmt,args...) printk( fmt, ##args )
	#else
	#define DPRINTK(fmt,args...)
	#endif

	#if defined(CONFIG_PROC_FS) && defined(CONFIG_STRAM_PROC)
	/* abbrev for the && above... */
	#define DO_PROC
	#include <linux/proc_fs.h>
	#include <linux/seq_file.h>
	#endif

	/*
	* ++roman:
	*
	* New version of ST-Ram buffer allocation. Instead of using the
	* 1 MB - 4 KB that remain when the ST-Ram chunk starts at $1000
	* (1 MB granularity!), such buffers are reserved like this:
	*
	* - If the kernel resides in ST-Ram anyway, we can take the buffer
	* from behind the current kernel data space the normal way
	* (incrementing start_mem).
	*
	* - If the kernel is in TT-Ram, stram_init() initializes start and
	* end of the available region. Buffers are allocated from there
	* and mem_init() later marks the such used pages as reserved.
	* Since each TT-Ram chunk is at least 4 MB in size, I hope there
	* won't be an overrun of the ST-Ram region by normal kernel data
	* space.
	*
	* For that, ST-Ram may only be allocated while kernel initialization
	* is going on, or exactly: before mem_init() is called. There is also
	* no provision now for freeing ST-Ram buffers. It seems that isn't
	* really needed.
	*
	*/

	/* Start and end (virtual) of ST-RAM */
	static void stram_start, stram_end;

	/* set after memory_init() executed and allocations via start_mem aren't
	* possible anymore */
	static int mem_init_done;

	/* set if kernel is in ST-RAM */
	static int kernel_in_stram;

	typedef struct stram_block {
	struct stram_block *next;
	void *start;
	unsigned long size;
	unsigned flags;
	const char *owner;
	} BLOCK;

	/* values for flags field */
	#define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */
	#define BLOCK_KMALLOCED 0x02 /* structure allocated by kmalloc() */
	#define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */

	/* list of allocated blocks */
	static BLOCK *alloc_list;

	/* We can't always use kmalloc() to allocate BLOCK structures, since
	* stram_alloc() can be called rather early. So we need some pool of
	* statically allocated structures. 20 of them is more than enough, so in most
	* cases we never should need to call kmalloc(). */
	#define N_STATIC_BLOCKS 20
	static BLOCK static_blocks[N_STATIC_BLOCKS];

	/*************************** Prototypes ***************************/

	static BLOCK add_region( void addr, unsigned long size );
	static BLOCK find_region( void addr );
	static int remove_region( BLOCK *block );

	/*********************** End of Prototypes ************************/


	/* ------------------------------------------------------------------------ */
	/* Public Interface */
	/* ------------------------------------------------------------------------ */

	/*
	* This init function is called very early by atari/config.c
	* It initializes some internal variables needed for stram_alloc()
	*/
	void __init atari_stram_init(void)
	{
	int i;

	/* initialize static blocks */
	for( i = 0; i < N_STATIC_BLOCKS; ++i )
	static_blocks[i].flags = BLOCK_FREE;

	/* determine whether kernel code resides in ST-RAM (then ST-RAM is the
	* first memory block at virtual 0x0) */
	stram_start = phys_to_virt(0);
	kernel_in_stram = (stram_start == 0);

	for( i = 0; i < m68k_num_memory; ++i ) {
	if (m68k_memory[i].addr == 0) {
	/* skip first 2kB or page (supervisor-only!) */
	stram_end = stram_start + m68k_memory[i].size;
	return;
	}
	}
	/* Should never come here! (There is always ST-Ram!) */
	panic( "atari_stram_init: no ST-RAM found!" );
	}


	/*
	* This function is called from setup_arch() to reserve the pages needed for
	* ST-RAM management.
	*/
	void __init atari_stram_reserve_pages(void *start_mem)
	{
	/* always reserve first page of ST-RAM, the first 2 kB are
	* supervisor-only! */
	if (!kernel_in_stram)
	reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT);

	}

	void atari_stram_mem_init_hook (void)
	{
	mem_init_done = 1;
	}


	/*
	* This is main public interface: somehow allocate a ST-RAM block
	*
	* - If we're before mem_init(), we have to make a static allocation. The
	* region is taken in the kernel data area (if the kernel is in ST-RAM) or
	* from the start of ST-RAM (if the kernel is in TT-RAM) and added to the
	* rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel
	* address space in the latter case.
	*
	* - If mem_init() already has been called, try with __get_dma_pages().
	* This has the disadvantage that it's very hard to get more than 1 page,
	* and it is likely to fail :-(
	*
	*/
	void atari_stram_alloc(long size, const char owner)
	{
	void *addr = NULL;
	BLOCK *block;
	int flags;

	DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner);

	if (!mem_init_done)
	return alloc_bootmem_low(size);
	else {
	/* After mem_init(): can only resort to __get_dma_pages() */
	addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size));
	flags = BLOCK_GFP;
	DPRINTK( "atari_stram_alloc: after mem_init, "
	"get_pages=%p\n", addr );
	}

	if (addr) {
	if (!(block = add_region( addr, size ))) {
	/* out of memory for BLOCK structure :-( */
	DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- "
	"freeing again\n" );
	free_pages((unsigned long)addr, get_order(size));
	return( NULL );
	}
	block->owner = owner;
	block->flags \|= flags;
	}
	return( addr );
	}
	EXPORT_SYMBOL(atari_stram_alloc);

	void atari_stram_free( void *addr )

	{
	BLOCK *block;

	DPRINTK( "atari_stram_free(addr=%p)\n", addr );

	if (!(block = find_region( addr ))) {
	printk( KERN_ERR "Attempt to free non-allocated ST-RAM block at %p "
	"from %p\n", addr, __builtin_return_address(0) );
	return;
	}
	DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, "
	"flags=%02x\n", block, block->size, block->owner, block->flags );

	if (!(block->flags & BLOCK_GFP))
	goto fail;

	DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n",
	get_order(block->size));
	free_pages((unsigned long)addr, get_order(block->size));
	remove_region( block );
	return;

	fail:
	printk( KERN_ERR "atari_stram_free: cannot free block at %p "
	"(called from %p)\n", addr, __builtin_return_address(0) );
	}
	EXPORT_SYMBOL(atari_stram_free);


	/* ------------------------------------------------------------------------ */
	/* Region Management */
	/* ------------------------------------------------------------------------ */


	/* insert a region into the alloced list (sorted) */
	static BLOCK add_region( void addr, unsigned long size )
	{
	BLOCK *p, n = NULL;
	int i;

	for( i = 0; i < N_STATIC_BLOCKS; ++i ) {
	if (static_blocks[i].flags & BLOCK_FREE) {
	n = &static_blocks[i];
	n->flags = 0;
	break;
	}
	}
	if (!n && mem_init_done) {
	/* if statics block pool exhausted and we can call kmalloc() already
	* (after mem_init()), try that */
	n = kmalloc( sizeof(BLOCK), GFP_KERNEL );
	if (n)
	n->flags = BLOCK_KMALLOCED;
	}
	if (!n) {
	printk( KERN_ERR "Out of memory for ST-RAM descriptor blocks\n" );
	return( NULL );
	}
	n->start = addr;
	n->size = size;

	for( p = &alloc_list; p; p = &((p)->next) )
	if ((*p)->start > addr) break;
	n->next = *p;
	*p = n;

	return( n );
	}


	/* find a region (by start addr) in the alloced list */
	static BLOCK find_region( void addr )
	{
	BLOCK *p;

	for( p = alloc_list; p; p = p->next ) {
	if (p->start == addr)
	return( p );
	if (p->start > addr)
	break;
	}
	return( NULL );
	}


	/* remove a block from the alloced list */
	static int remove_region( BLOCK *block )
	{
	BLOCK **p;

	for( p = &alloc_list; p; p = &((p)->next) )
	if (*p == block) break;
	if (!*p)
	return( 0 );

	*p = block->next;
	if (block->flags & BLOCK_KMALLOCED)
	kfree( block );
	else
	block->flags \|= BLOCK_FREE;
	return( 1 );
	}



	/* ------------------------------------------------------------------------ */
	/* /proc statistics file stuff */
	/* ------------------------------------------------------------------------ */

	#ifdef DO_PROC

	#define PRINT_PROC(fmt,args...) seq_printf( m, fmt, ##args )

	static int stram_proc_show(struct seq_file m, void v)
	{
	BLOCK *p;

	PRINT_PROC("Total ST-RAM: %8u kB\n",
	(stram_end - stram_start) >> 10);
	PRINT_PROC( "Allocated regions:\n" );
	for( p = alloc_list; p; p = p->next ) {
	PRINT_PROC("0x%08lx-0x%08lx: %s (",
	virt_to_phys(p->start),
	virt_to_phys(p->start+p->size-1),
	p->owner);
	if (p->flags & BLOCK_GFP)
	PRINT_PROC( "page-alloced)\n" );
	else
	PRINT_PROC( "??)\n" );
	}

	return 0;
	}

	static int stram_proc_open(struct inode inode, struct file file)
	{
	return single_open(file, stram_proc_show, NULL);
	}

	static const struct file_operations stram_proc_fops = {
	.open = stram_proc_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static int __init proc_stram_init(void)
	{
	proc_create("stram", 0, NULL, &stram_proc_fops);
	return 0;
	}
	module_init(proc_stram_init);
	#endif


	/*
	* Local variables:
	* c-indent-level: 4
	* tab-width: 4
	* End:
	*/