[net-next-2.6.git] / drivers / staging / dt3155 / allocator.c

/*
 * allocator.c -- allocate after high_memory, if available
 *
 * NOTE: this is different from my previous allocator, the one that
 *       assembles pages, which revealed itself both slow and unreliable.
 *
 * Copyright (C) 1998   rubini@linux.it (Alessandro Rubini)
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *

-- Changes --

  Date	      Programmer  Description of changes made
  -------------------------------------------------------------------
  02-Aug-2002 NJC         allocator now steps in 1MB increments, rather
			  than doubling its size each time.
			  Also, allocator_init(u32 *) now returns
			  (in the first arg) the size of the free
			  space.  This is no longer consistent with
			  using the allocator as a module, and some changes
			  may be necessary for that purpose.  This was
			  designed to work with the DT3155 driver, in
			  stand alone mode only!!!
  26-Oct-2009 SS	  Port to 2.6.30 kernel.
 */


#ifndef __KERNEL__
#  define __KERNEL__
#endif
#ifndef MODULE
#  define MODULE
#endif

#include <linux/version.h>

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/mm.h>	/* PAGE_ALIGN() */
#include <linux/io.h>

#include <asm/page.h>

/*#define ALL_DEBUG*/
#define ALL_MSG "allocator: "

#undef PDEBUG             /* undef it, just in case */
#ifdef ALL_DEBUG
#  define __static
#  define DUMP_LIST() dump_list()
#  ifdef __KERNEL__
     /* This one if debugging is on, and kernel space */
#    define PDEBUG(fmt, args...) printk(KERN_DEBUG ALL_MSG fmt, ## args)
#  else
     /* This one for user space */
#    define PDEBUG(fmt, args...) fprintf(stderr, fmt, ## args)
#  endif
#else
#  define PDEBUG(fmt, args...) /* not debugging: nothing */
#  define DUMP_LIST()
#  define __static static
#endif

#undef PDEBUGG
#define PDEBUGG(fmt, args...)
/*#define PDEBUGG(fmt, args...) printk( KERN_DEBUG ALL_MSG fmt, ## args)*/


int allocator_himem = 1; /* 0 = probe, pos. = megs, neg. = disable   */
int allocator_step = 1;  /* This is the step size in MB              */
int allocator_probe = 1; /* This is a flag -- 1=probe, 0=don't probe */

static unsigned long allocator_buffer;		/* physical address */
static unsigned long allocator_buffer_size;	/* kilobytes */

/*
 * The allocator keeps a list of DMA areas, so multiple devices
 * can coexist. The list is kept sorted by address
 */

struct allocator_struct {
	unsigned long address;
	unsigned long size;
	struct allocator_struct *next;
};

struct allocator_struct *allocator_list;


#ifdef ALL_DEBUG
static int dump_list(void)
{
	struct allocator_struct *ptr;

	PDEBUG("Current list:\n");
	for (ptr = allocator_list; ptr; ptr = ptr->next)
		PDEBUG("0x%08lx (size %likB)\n", ptr->address, ptr->size>>10);
	return 0;
}
#endif

/* ========================================================================
 * This function is the actual allocator.
 *
 * If space is available in high memory (as detected at load time), that
 * one is returned. The return value is a physical address (i.e., it can
 * be used straight ahead for DMA, but needs remapping for program use).
 */

unsigned long allocator_allocate_dma(unsigned long kilobytes, int prio)
{
	struct allocator_struct *ptr = allocator_list, *newptr;
	unsigned long bytes = kilobytes << 10;

	/* check if high memory is available */
	if (!allocator_buffer)
		return 0;

	/* Round it to a multiple of the pagesize */
	bytes = PAGE_ALIGN(bytes);
	PDEBUG("request for %li bytes\n", bytes);

	while (ptr && ptr->next) {
		if (ptr->next->address - (ptr->address + ptr->size) >= bytes)
			break; /* enough space */
		ptr = ptr->next;
	}
	if (!ptr->next) {
		DUMP_LIST();
		PDEBUG("alloc failed\n");
		return 0; /* end of list */
	}
	newptr = kmalloc(sizeof(struct allocator_struct), prio);
	if (!newptr)
		return 0;

	/* ok, now stick it after ptr */
	newptr->address = ptr->address + ptr->size;
	newptr->size = bytes;
	newptr->next = ptr->next;
	ptr->next = newptr;

	DUMP_LIST();
	PDEBUG("returning 0x%08lx\n", newptr->address);
	return newptr->address;
}

int allocator_free_dma(unsigned long address)
{
	struct allocator_struct *ptr = allocator_list, *prev;

	while (ptr && ptr->next) {
		if (ptr->next->address == address)
			break;
		ptr = ptr->next;
	}
	/* the one being freed is ptr->next */
	prev = ptr; ptr = ptr->next;

	if (!ptr) {
		printk(KERN_ERR ALL_MSG
			"free_dma(0x%08lx) but add. not allocated\n",
			ptr->address);
		return -EINVAL;
	}
	PDEBUGG("freeing: %08lx (%li) next %08lx\n", ptr->address, ptr->size,
		ptr->next->address);
	prev->next = ptr->next;
	kfree(ptr);

	/* dump_list(); */
	return 0;
}

/* ========================================================================
 * Init and cleanup
 *
 * On cleanup everything is released. If the list is not empty, that a
 * problem of our clients
 */
int allocator_init(u32 *allocator_max)
{
	/* check how much free memory is there */
	void *remapped;
	unsigned long max;
	unsigned long trial_size = allocator_himem<<20;
	unsigned long last_trial = 0;
	unsigned long step = allocator_step<<20;
	unsigned long i = 0;
	struct allocator_struct *head, *tail;
	char test_string[] = "0123456789abcde"; /* 16 bytes */

	PDEBUGG("himem = %i\n", allocator_himem);
	if (allocator_himem < 0) /* don't even try */
		return -EINVAL;

	if (!trial_size)
		trial_size = 1<<20; /* not specified: try one meg */

	while (1) {
		remapped = ioremap(__pa(high_memory), trial_size);
		if (!remapped) {
			PDEBUGG("%li megs failed!\n", trial_size>>20);
			break;
		}
		PDEBUGG("Trying %li megs (at %p, %p)\n", trial_size>>20,
			(void *)__pa(high_memory), remapped);
		for (i = last_trial; i < trial_size; i += 16) {
			strcpy((char *)(remapped)+i, test_string);
			if (strcmp((char *)(remapped)+i, test_string))
				break;
			}
		iounmap((void *)remapped);
		schedule();
		last_trial = trial_size;
		if (i == trial_size)
			trial_size += step; /* increment, if all went well */
		else {
			PDEBUGG("%li megs copy test failed!\n", trial_size>>20);
			break;
		}
		if (!allocator_probe)
			break;
	}
	PDEBUG("%li megs (%li k, %li b)\n", i>>20, i>>10, i);
	allocator_buffer_size = i>>10; /* kilobytes */
	allocator_buffer = __pa(high_memory);
	if (!allocator_buffer_size) {
		printk(KERN_WARNING ALL_MSG "no free high memory to use\n");
		return -ENOMEM;
	}

	/*
	* to simplify things, always have two cells in the list:
	* the first and the last. This avoids some conditionals and
	* extra code when allocating and deallocating: we only play
	* in the middle of the list
	*/
	head = kmalloc(sizeof(struct allocator_struct), GFP_KERNEL);
	if (!head)
		return -ENOMEM;
	tail = kmalloc(sizeof(struct allocator_struct), GFP_KERNEL);
	if (!tail) {
		kfree(head);
		return -ENOMEM;
	}

	max = allocator_buffer_size<<10;

	head->size = tail->size = 0;
	head->address = allocator_buffer;
	tail->address = allocator_buffer + max;
	head->next = tail;
	tail->next = NULL;
	allocator_list = head;

	/* Back to the user code, in KB */
	*allocator_max = allocator_buffer_size;

	return 0; /* ok, ready */
}

void allocator_cleanup(void)
{
	struct allocator_struct *ptr, *next;

	for (ptr = allocator_list; ptr; ptr = next) {
		next = ptr->next;
		PDEBUG("freeing list: 0x%08lx\n", ptr->address);
		kfree(ptr);
	}

	allocator_buffer      = 0;
	allocator_buffer_size = 0;
	allocator_list = NULL;
}
Commit	Line	Data
aa337ef1 SS	1	/*
	2	* allocator.c -- allocate after high_memory, if available
	3	*
	4	* NOTE: this is different from my previous allocator, the one that
	5	* assembles pages, which revealed itself both slow and unreliable.
	6	*
	7	* Copyright (C) 1998 rubini@linux.it (Alessandro Rubini)
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2 of the License, or
	12	* (at your option) any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to the Free Software
	21	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	22	*
	23
	24	-- Changes --
	25
	26	Date Programmer Description of changes made
	27	-------------------------------------------------------------------
	28	02-Aug-2002 NJC allocator now steps in 1MB increments, rather
1769fd86	29	than doubling its size each time.
dcff74ce	30	Also, allocator_init(u32 *) now returns
aa337ef1 SS	31	(in the first arg) the size of the free
	32	space. This is no longer consistent with
	33	using the allocator as a module, and some changes
	34	may be necessary for that purpose. This was
	35	designed to work with the DT3155 driver, in
	36	stand alone mode only!!!
	37	26-Oct-2009 SS Port to 2.6.30 kernel.
	38	*/
	39
	40
	41	#ifndef __KERNEL__
	42	# define __KERNEL__
	43	#endif
	44	#ifndef MODULE
	45	# define MODULE
	46	#endif
	47
	48	#include <linux/version.h>
	49
	50	#include <linux/sched.h>
	51	#include <linux/kernel.h>
	52	#include <linux/fs.h>
	53	#include <linux/proc_fs.h>
	54	#include <linux/errno.h>
	55	#include <linux/types.h>
	56	#include <linux/mm.h> /* PAGE_ALIGN() */
2141ec62	57	#include <linux/io.h>
aa337ef1 SS	58
	59	#include <asm/page.h>
	60
aa337ef1 SS	61	/#define ALL_DEBUG/
	62	#define ALL_MSG "allocator: "
	63
	64	#undef PDEBUG /* undef it, just in case */
	65	#ifdef ALL_DEBUG
	66	# define __static
	67	# define DUMP_LIST() dump_list()
	68	# ifdef __KERNEL__
	69	/* This one if debugging is on, and kernel space */
1769fd86	70	# define PDEBUG(fmt, args...) printk(KERN_DEBUG ALL_MSG fmt, ## args)
aa337ef1 SS	71	# else
	72	/* This one for user space */
	73	# define PDEBUG(fmt, args...) fprintf(stderr, fmt, ## args)
	74	# endif
	75	#else
	76	# define PDEBUG(fmt, args...) /* not debugging: nothing */
	77	# define DUMP_LIST()
	78	# define __static static
	79	#endif
	80
	81	#undef PDEBUGG
	82	#define PDEBUGG(fmt, args...)
	83	/#define PDEBUGG(fmt, args...) printk( KERN_DEBUG ALL_MSG fmt, ## args)/
	84
	85
	86	int allocator_himem = 1; /* 0 = probe, pos. = megs, neg. = disable */
	87	int allocator_step = 1; /* This is the step size in MB */
	88	int allocator_probe = 1; /* This is a flag -- 1=probe, 0=don't probe */
	89
1769fd86 GKH	90	static unsigned long allocator_buffer; /* physical address */
1769fd86 GKH	91	static unsigned long allocator_buffer_size; /* kilobytes */
aa337ef1 SS	92
	93	/*
	94	* The allocator keeps a list of DMA areas, so multiple devices
	95	* can coexist. The list is kept sorted by address
	96	*/
	97
	98	struct allocator_struct {
1769fd86 GKH	99	unsigned long address;
	100	unsigned long size;
	101	struct allocator_struct *next;
aa337ef1 SS	102	};
aa337ef1 SS	103
1769fd86	104	struct allocator_struct *allocator_list;
aa337ef1 SS	105
	106
	107	#ifdef ALL_DEBUG
	108	static int dump_list(void)
	109	{
1769fd86	110	struct allocator_struct *ptr;
aa337ef1	111
1769fd86 GKH	112	PDEBUG("Current list:\n");
	113	for (ptr = allocator_list; ptr; ptr = ptr->next)
	114	PDEBUG("0x%08lx (size %likB)\n", ptr->address, ptr->size>>10);
	115	return 0;
aa337ef1 SS	116	}
	117	#endif
	118
	119	/* ========================================================================
	120	* This function is the actual allocator.
	121	*
	122	* If space is available in high memory (as detected at load time), that
	123	* one is returned. The return value is a physical address (i.e., it can
	124	* be used straight ahead for DMA, but needs remapping for program use).
	125	*/
	126
1769fd86	127	unsigned long allocator_allocate_dma(unsigned long kilobytes, int prio)
aa337ef1	128	{
1769fd86 GKH	129	struct allocator_struct ptr = allocator_list, newptr;
	130	unsigned long bytes = kilobytes << 10;
	131
	132	/* check if high memory is available */
	133	if (!allocator_buffer)
	134	return 0;
	135
	136	/* Round it to a multiple of the pagesize */
	137	bytes = PAGE_ALIGN(bytes);
	138	PDEBUG("request for %li bytes\n", bytes);
	139
	140	while (ptr && ptr->next) {
	141	if (ptr->next->address - (ptr->address + ptr->size) >= bytes)
	142	break; /* enough space */
	143	ptr = ptr->next;
	144	}
	145	if (!ptr->next) {
	146	DUMP_LIST();
	147	PDEBUG("alloc failed\n");
	148	return 0; /* end of list */
	149	}
	150	newptr = kmalloc(sizeof(struct allocator_struct), prio);
	151	if (!newptr)
	152	return 0;
	153
	154	/* ok, now stick it after ptr */
	155	newptr->address = ptr->address + ptr->size;
	156	newptr->size = bytes;
	157	newptr->next = ptr->next;
	158	ptr->next = newptr;
	159
	160	DUMP_LIST();
	161	PDEBUG("returning 0x%08lx\n", newptr->address);
	162	return newptr->address;
aa337ef1 SS	163	}
aa337ef1 SS	164
1769fd86	165	int allocator_free_dma(unsigned long address)
aa337ef1	166	{
1769fd86	167	struct allocator_struct ptr = allocator_list, prev;
aa337ef1	168
1769fd86 GKH	169	while (ptr && ptr->next) {
	170	if (ptr->next->address == address)
	171	break;
	172	ptr = ptr->next;
	173	}
	174	/* the one being freed is ptr->next */
	175	prev = ptr; ptr = ptr->next;
	176
	177	if (!ptr) {
	178	printk(KERN_ERR ALL_MSG
	179	"free_dma(0x%08lx) but add. not allocated\n",
	180	ptr->address);
	181	return -EINVAL;
aa337ef1	182	}
1769fd86 GKH	183	PDEBUGG("freeing: %08lx (%li) next %08lx\n", ptr->address, ptr->size,
	184	ptr->next->address);
	185	prev->next = ptr->next;
	186	kfree(ptr);
	187
	188	/* dump_list(); */
	189	return 0;
aa337ef1 SS	190	}
	191
	192	/* ========================================================================
	193	* Init and cleanup
	194	*
	195	* On cleanup everything is released. If the list is not empty, that a
	196	* problem of our clients
	197	*/
3a8954e8	198	int allocator_init(u32 *allocator_max)
aa337ef1	199	{
1769fd86 GKH	200	/* check how much free memory is there */
	201	void *remapped;
	202	unsigned long max;
	203	unsigned long trial_size = allocator_himem<<20;
	204	unsigned long last_trial = 0;
	205	unsigned long step = allocator_step<<20;
	206	unsigned long i = 0;
	207	struct allocator_struct head, tail;
	208	char test_string[] = "0123456789abcde"; /* 16 bytes */
	209
	210	PDEBUGG("himem = %i\n", allocator_himem);
	211	if (allocator_himem < 0) /* don't even try */
	212	return -EINVAL;
	213
	214	if (!trial_size)
	215	trial_size = 1<<20; /* not specified: try one meg */
	216
	217	while (1) {
	218	remapped = ioremap(__pa(high_memory), trial_size);
	219	if (!remapped) {
	220	PDEBUGG("%li megs failed!\n", trial_size>>20);
	221	break;
	222	}
	223	PDEBUGG("Trying %li megs (at %p, %p)\n", trial_size>>20,
	224	(void *)__pa(high_memory), remapped);
	225	for (i = last_trial; i < trial_size; i += 16) {
	226	strcpy((char *)(remapped)+i, test_string);
	227	if (strcmp((char *)(remapped)+i, test_string))
	228	break;
	229	}
	230	iounmap((void *)remapped);
	231	schedule();
	232	last_trial = trial_size;
	233	if (i == trial_size)
	234	trial_size += step; /* increment, if all went well */
	235	else {
	236	PDEBUGG("%li megs copy test failed!\n", trial_size>>20);
	237	break;
	238	}
	239	if (!allocator_probe)
	240	break;
	241	}
	242	PDEBUG("%li megs (%li k, %li b)\n", i>>20, i>>10, i);
	243	allocator_buffer_size = i>>10; /* kilobytes */
	244	allocator_buffer = __pa(high_memory);
	245	if (!allocator_buffer_size) {
	246	printk(KERN_WARNING ALL_MSG "no free high memory to use\n");
	247	return -ENOMEM;
	248	}
	249
	250	/*
	251	* to simplify things, always have two cells in the list:
	252	* the first and the last. This avoids some conditionals and
	253	* extra code when allocating and deallocating: we only play
	254	* in the middle of the list
	255	*/
	256	head = kmalloc(sizeof(struct allocator_struct), GFP_KERNEL);
	257	if (!head)
	258	return -ENOMEM;
	259	tail = kmalloc(sizeof(struct allocator_struct), GFP_KERNEL);
	260	if (!tail) {
	261	kfree(head);
	262	return -ENOMEM;
	263	}
264
265	max = allocator_buffer_size<<10;
266
267	head->size = tail->size = 0;
268	head->address = allocator_buffer;
269	tail->address = allocator_buffer + max;
270	head->next = tail;
271	tail->next = NULL;
272	allocator_list = head;
273
274	/* Back to the user code, in KB */
275	*allocator_max = allocator_buffer_size;
276
277	return 0; /* ok, ready */
aa337ef1 SS	278	}
	279
	280	void allocator_cleanup(void)
	281	{
1769fd86	282	struct allocator_struct ptr, next;
aa337ef1	283
1769fd86 GKH	284	for (ptr = allocator_list; ptr; ptr = next) {
	285	next = ptr->next;
	286	PDEBUG("freeing list: 0x%08lx\n", ptr->address);
	287	kfree(ptr);
	288	}
aa337ef1	289
1769fd86 GKH	290	allocator_buffer = 0;
	291	allocator_buffer_size = 0;
	292	allocator_list = NULL;
aa337ef1 SS	293	}
	294
	295