[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / powerpc / mm / imalloc.c

/*
 * c 2001 PPC 64 Team, IBM Corp
 * 
 *      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.
 */

#include <linux/slab.h>
#include <linux/vmalloc.h>

#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/semaphore.h>
#include <asm/imalloc.h>
#include <asm/cacheflush.h>

static DECLARE_MUTEX(imlist_sem);
struct vm_struct * imlist = NULL;

static int get_free_im_addr(unsigned long size, unsigned long *im_addr)
{
	unsigned long addr;
	struct vm_struct **p, *tmp;

	addr = ioremap_bot;
	for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
		if (size + addr < (unsigned long) tmp->addr)
			break;
		if ((unsigned long)tmp->addr >= ioremap_bot)
			addr = tmp->size + (unsigned long) tmp->addr;
		if (addr >= IMALLOC_END-size)
			return 1;
	}
	*im_addr = addr;

	return 0;
}

/* Return whether the region described by v_addr and size is a subset
 * of the region described by parent
 */
static inline int im_region_is_subset(unsigned long v_addr, unsigned long size,
			struct vm_struct *parent)
{
	return (int) (v_addr >= (unsigned long) parent->addr &&
	              v_addr < (unsigned long) parent->addr + parent->size &&
	    	      size < parent->size);
}

/* Return whether the region described by v_addr and size is a superset
 * of the region described by child
 */
static int im_region_is_superset(unsigned long v_addr, unsigned long size,
		struct vm_struct *child)
{
	struct vm_struct parent;

	parent.addr = (void *) v_addr;
	parent.size = size;

	return im_region_is_subset((unsigned long) child->addr, child->size,
			&parent);
}

/* Return whether the region described by v_addr and size overlaps
 * the region described by vm.  Overlapping regions meet the
 * following conditions:
 * 1) The regions share some part of the address space
 * 2) The regions aren't identical
 * 3) Neither region is a subset of the other
 */
static int im_region_overlaps(unsigned long v_addr, unsigned long size,
		     struct vm_struct *vm)
{
	if (im_region_is_superset(v_addr, size, vm))
		return 0;

	return (v_addr + size > (unsigned long) vm->addr + vm->size &&
		v_addr < (unsigned long) vm->addr + vm->size) ||
	       (v_addr < (unsigned long) vm->addr &&
		v_addr + size > (unsigned long) vm->addr);
}

/* Determine imalloc status of region described by v_addr and size.
 * Can return one of the following:
 * IM_REGION_UNUSED   -  Entire region is unallocated in imalloc space.
 * IM_REGION_SUBSET -    Region is a subset of a region that is already
 * 			 allocated in imalloc space.
 * 		         vm will be assigned to a ptr to the parent region.
 * IM_REGION_EXISTS -    Exact region already allocated in imalloc space.
 *                       vm will be assigned to a ptr to the existing imlist
 *                       member.
 * IM_REGION_OVERLAPS -  Region overlaps an allocated region in imalloc space.
 * IM_REGION_SUPERSET -  Region is a superset of a region that is already
 *                       allocated in imalloc space.
 */
static int im_region_status(unsigned long v_addr, unsigned long size,
		    struct vm_struct **vm)
{
	struct vm_struct *tmp;

	for (tmp = imlist; tmp; tmp = tmp->next)
		if (v_addr < (unsigned long) tmp->addr + tmp->size)
			break;

	if (tmp) {
		if (im_region_overlaps(v_addr, size, tmp))
			return IM_REGION_OVERLAP;

		*vm = tmp;
		if (im_region_is_subset(v_addr, size, tmp)) {
			/* Return with tmp pointing to superset */
			return IM_REGION_SUBSET;
		}
		if (im_region_is_superset(v_addr, size, tmp)) {
			/* Return with tmp pointing to first subset */
			return IM_REGION_SUPERSET;
		}
		else if (v_addr == (unsigned long) tmp->addr &&
		 	 size == tmp->size) {
			/* Return with tmp pointing to exact region */
			return IM_REGION_EXISTS;
		}
	}

	*vm = NULL;
	return IM_REGION_UNUSED;
}

static struct vm_struct * split_im_region(unsigned long v_addr, 
		unsigned long size, struct vm_struct *parent)
{
	struct vm_struct *vm1 = NULL;
	struct vm_struct *vm2 = NULL;
	struct vm_struct *new_vm = NULL;
	
	vm1 = (struct vm_struct *) kmalloc(sizeof(*vm1), GFP_KERNEL);
	if (vm1	== NULL) {
		printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
		return NULL;
	}

	if (v_addr == (unsigned long) parent->addr) {
	        /* Use existing parent vm_struct to represent child, allocate
		 * new one for the remainder of parent range
		 */
		vm1->size = parent->size - size;
		vm1->addr = (void *) (v_addr + size);
		vm1->next = parent->next;

		parent->size = size;
		parent->next = vm1;
		new_vm = parent;
	} else if (v_addr + size == (unsigned long) parent->addr + 
			parent->size) {
		/* Allocate new vm_struct to represent child, use existing
		 * parent one for remainder of parent range
		 */
		vm1->size = size;
		vm1->addr = (void *) v_addr;
		vm1->next = parent->next;
		new_vm = vm1;

		parent->size -= size;
		parent->next = vm1;
	} else {
	        /* Allocate two new vm_structs for the new child and 
		 * uppermost remainder, and use existing parent one for the
		 * lower remainder of parent range
		 */
		vm2 = (struct vm_struct *) kmalloc(sizeof(*vm2), GFP_KERNEL);
		if (vm2 == NULL) {
			printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
			kfree(vm1);
			return NULL;
		}

		vm1->size = size;
		vm1->addr = (void *) v_addr;
		vm1->next = vm2;
		new_vm = vm1;

		vm2->size = ((unsigned long) parent->addr + parent->size) - 
				(v_addr + size);
		vm2->addr = (void *) v_addr + size;
		vm2->next = parent->next;

		parent->size = v_addr - (unsigned long) parent->addr;
		parent->next = vm1;
	}

	return new_vm;
}

static struct vm_struct * __add_new_im_area(unsigned long req_addr, 
					    unsigned long size)
{
	struct vm_struct **p, *tmp, *area;
		
	for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
		if (req_addr + size <= (unsigned long)tmp->addr)
			break;
	}
	
	area = (struct vm_struct *) kmalloc(sizeof(*area), GFP_KERNEL);
	if (!area)
		return NULL;
	area->flags = 0;
	area->addr = (void *)req_addr;
	area->size = size;
	area->next = *p;
	*p = area;

	return area;
}

static struct vm_struct * __im_get_area(unsigned long req_addr, 
					unsigned long size,
					int criteria)
{
	struct vm_struct *tmp;
	int status;

	status = im_region_status(req_addr, size, &tmp);
	if ((criteria & status) == 0) {
		return NULL;
	}
	
	switch (status) {
	case IM_REGION_UNUSED:
		tmp = __add_new_im_area(req_addr, size);
		break;
	case IM_REGION_SUBSET:
		tmp = split_im_region(req_addr, size, tmp);
		break;
	case IM_REGION_EXISTS:
		/* Return requested region */
		break;
	case IM_REGION_SUPERSET:
		/* Return first existing subset of requested region */
		break;
	default:
		printk(KERN_ERR "%s() unexpected imalloc region status\n",
				__FUNCTION__);
		tmp = NULL;
	}

	return tmp;
}

struct vm_struct * im_get_free_area(unsigned long size)
{
	struct vm_struct *area;
	unsigned long addr;
	
	down(&imlist_sem);
	if (get_free_im_addr(size, &addr)) {
		printk(KERN_ERR "%s() cannot obtain addr for size 0x%lx\n",
				__FUNCTION__, size);
		area = NULL;
		goto next_im_done;
	}

	area = __im_get_area(addr, size, IM_REGION_UNUSED);
	if (area == NULL) {
		printk(KERN_ERR 
		       "%s() cannot obtain area for addr 0x%lx size 0x%lx\n",
			__FUNCTION__, addr, size);
	}
next_im_done:
	up(&imlist_sem);
	return area;
}

struct vm_struct * im_get_area(unsigned long v_addr, unsigned long size,
		int criteria)
{
	struct vm_struct *area;

	down(&imlist_sem);
	area = __im_get_area(v_addr, size, criteria);
	up(&imlist_sem);
	return area;
}

void im_free(void * addr)
{
	struct vm_struct **p, *tmp;
  
	if (!addr)
		return;
	if ((unsigned long) addr & ~PAGE_MASK) {
		printk(KERN_ERR "Trying to %s bad address (%p)\n", __FUNCTION__,			addr);
		return;
	}
	down(&imlist_sem);
	for (p = &imlist ; (tmp = *p) ; p = &tmp->next) {
		if (tmp->addr == addr) {
			*p = tmp->next;
			unmap_vm_area(tmp);
			kfree(tmp);
			up(&imlist_sem);
			return;
		}
	}
	up(&imlist_sem);
	printk(KERN_ERR "Trying to %s nonexistent area (%p)\n", __FUNCTION__,
			addr);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* c 2001 PPC 64 Team, IBM Corp
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version
	7	* 2 of the License, or (at your option) any later version.
	8	*/
	9
	10	#include <linux/slab.h>
	11	#include <linux/vmalloc.h>
	12
	13	#include <asm/uaccess.h>
	14	#include <asm/pgalloc.h>
	15	#include <asm/pgtable.h>
	16	#include <asm/semaphore.h>
1f8d419e	17	#include <asm/imalloc.h>
20cee16c	18	#include <asm/cacheflush.h>
1da177e4 LT	19
	20	static DECLARE_MUTEX(imlist_sem);
	21	struct vm_struct * imlist = NULL;
	22
	23	static int get_free_im_addr(unsigned long size, unsigned long *im_addr)
	24	{
	25	unsigned long addr;
	26	struct vm_struct *p, tmp;
	27
1f8d419e	28	addr = ioremap_bot;
1da177e4 LT	29	for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
	30	if (size + addr < (unsigned long) tmp->addr)
	31	break;
1f8d419e	32	if ((unsigned long)tmp->addr >= ioremap_bot)
1da177e4	33	addr = tmp->size + (unsigned long) tmp->addr;
e28f7faf	34	if (addr >= IMALLOC_END-size)
1da177e4 LT	35	return 1;
	36	}
	37	*im_addr = addr;
	38
	39	return 0;
	40	}
	41
	42	/* Return whether the region described by v_addr and size is a subset
	43	* of the region described by parent
	44	*/
	45	static inline int im_region_is_subset(unsigned long v_addr, unsigned long size,
	46	struct vm_struct *parent)
	47	{
	48	return (int) (v_addr >= (unsigned long) parent->addr &&
	49	v_addr < (unsigned long) parent->addr + parent->size &&
	50	size < parent->size);
	51	}
	52
	53	/* Return whether the region described by v_addr and size is a superset
	54	* of the region described by child
	55	*/
	56	static int im_region_is_superset(unsigned long v_addr, unsigned long size,
	57	struct vm_struct *child)
	58	{
	59	struct vm_struct parent;
	60
	61	parent.addr = (void *) v_addr;
	62	parent.size = size;
	63
	64	return im_region_is_subset((unsigned long) child->addr, child->size,
	65	&parent);
	66	}
	67
	68	/* Return whether the region described by v_addr and size overlaps
	69	* the region described by vm. Overlapping regions meet the
	70	* following conditions:
	71	* 1) The regions share some part of the address space
	72	* 2) The regions aren't identical
	73	* 3) Neither region is a subset of the other
	74	*/
	75	static int im_region_overlaps(unsigned long v_addr, unsigned long size,
	76	struct vm_struct *vm)
	77	{
	78	if (im_region_is_superset(v_addr, size, vm))
	79	return 0;
	80
	81	return (v_addr + size > (unsigned long) vm->addr + vm->size &&
	82	v_addr < (unsigned long) vm->addr + vm->size) \|\|
	83	(v_addr < (unsigned long) vm->addr &&
	84	v_addr + size > (unsigned long) vm->addr);
	85	}
	86
	87	/* Determine imalloc status of region described by v_addr and size.
	88	* Can return one of the following:
	89	* IM_REGION_UNUSED - Entire region is unallocated in imalloc space.
	90	* IM_REGION_SUBSET - Region is a subset of a region that is already
	91	* allocated in imalloc space.
	92	* vm will be assigned to a ptr to the parent region.
	93	* IM_REGION_EXISTS - Exact region already allocated in imalloc space.
	94	* vm will be assigned to a ptr to the existing imlist
	95	* member.
	96	* IM_REGION_OVERLAPS - Region overlaps an allocated region in imalloc space.
	97	* IM_REGION_SUPERSET - Region is a superset of a region that is already
	98	* allocated in imalloc space.
99	*/
100	static int im_region_status(unsigned long v_addr, unsigned long size,
101	struct vm_struct **vm)
102	{
103	struct vm_struct *tmp;
104
105	for (tmp = imlist; tmp; tmp = tmp->next)
106	if (v_addr < (unsigned long) tmp->addr + tmp->size)
107	break;
108
109	if (tmp) {
110	if (im_region_overlaps(v_addr, size, tmp))
111	return IM_REGION_OVERLAP;
112
113	*vm = tmp;
114	if (im_region_is_subset(v_addr, size, tmp)) {
115	/* Return with tmp pointing to superset */
116	return IM_REGION_SUBSET;
117	}
118	if (im_region_is_superset(v_addr, size, tmp)) {
119	/* Return with tmp pointing to first subset */
120	return IM_REGION_SUPERSET;
121	}
122	else if (v_addr == (unsigned long) tmp->addr &&
123	size == tmp->size) {
124	/* Return with tmp pointing to exact region */
125	return IM_REGION_EXISTS;
126	}
127	}
128
129	*vm = NULL;
130	return IM_REGION_UNUSED;
131	}
132
133	static struct vm_struct * split_im_region(unsigned long v_addr,
134	unsigned long size, struct vm_struct *parent)
135	{
136	struct vm_struct *vm1 = NULL;
137	struct vm_struct *vm2 = NULL;
138	struct vm_struct *new_vm = NULL;
139
140	vm1 = (struct vm_struct ) kmalloc(sizeof(vm1), GFP_KERNEL);
141	if (vm1 == NULL) {
142	printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
143	return NULL;
144	}
145
146	if (v_addr == (unsigned long) parent->addr) {
147	/* Use existing parent vm_struct to represent child, allocate
148	* new one for the remainder of parent range
149	*/
150	vm1->size = parent->size - size;
151	vm1->addr = (void *) (v_addr + size);
152	vm1->next = parent->next;
153
154	parent->size = size;
155	parent->next = vm1;
156	new_vm = parent;
157	} else if (v_addr + size == (unsigned long) parent->addr +
158	parent->size) {
159	/* Allocate new vm_struct to represent child, use existing
160	* parent one for remainder of parent range
161	*/
162	vm1->size = size;
163	vm1->addr = (void *) v_addr;
164	vm1->next = parent->next;
165	new_vm = vm1;
166
167	parent->size -= size;
168	parent->next = vm1;
169	} else {
170	/* Allocate two new vm_structs for the new child and
171	* uppermost remainder, and use existing parent one for the
172	* lower remainder of parent range
173	*/
174	vm2 = (struct vm_struct ) kmalloc(sizeof(vm2), GFP_KERNEL);
175	if (vm2 == NULL) {
176	printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
177	kfree(vm1);
178	return NULL;
179	}
180
181	vm1->size = size;
182	vm1->addr = (void *) v_addr;
183	vm1->next = vm2;
184	new_vm = vm1;
185
186	vm2->size = ((unsigned long) parent->addr + parent->size) -
187	(v_addr + size);
188	vm2->addr = (void *) v_addr + size;
189	vm2->next = parent->next;
190
191	parent->size = v_addr - (unsigned long) parent->addr;
192	parent->next = vm1;
193	}
194
195	return new_vm;
196	}
197
198	static struct vm_struct * __add_new_im_area(unsigned long req_addr,
199	unsigned long size)
200	{
201	struct vm_struct *p, tmp, *area;
202
203	for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
204	if (req_addr + size <= (unsigned long)tmp->addr)
205	break;
206	}
207
208	area = (struct vm_struct ) kmalloc(sizeof(area), GFP_KERNEL);
209	if (!area)
210	return NULL;
211	area->flags = 0;
212	area->addr = (void *)req_addr;
213	area->size = size;
214	area->next = *p;
215	*p = area;
216
217	return area;
218	}
219
220	static struct vm_struct * __im_get_area(unsigned long req_addr,
221	unsigned long size,
222	int criteria)
223	{
224	struct vm_struct *tmp;
225	int status;
226
227	status = im_region_status(req_addr, size, &tmp);
228	if ((criteria & status) == 0) {
229	return NULL;
230	}
231
232	switch (status) {
233	case IM_REGION_UNUSED:
234	tmp = __add_new_im_area(req_addr, size);
235	break;
236	case IM_REGION_SUBSET:
237	tmp = split_im_region(req_addr, size, tmp);
238	break;
239	case IM_REGION_EXISTS:
240	/* Return requested region */
241	break;
242	case IM_REGION_SUPERSET:
243	/* Return first existing subset of requested region */
244	break;
245	default:
246	printk(KERN_ERR "%s() unexpected imalloc region status\n",
247	__FUNCTION__);
248	tmp = NULL;
249	}
250
251	return tmp;
252	}
253
254	struct vm_struct * im_get_free_area(unsigned long size)
255	{
256	struct vm_struct *area;
257	unsigned long addr;
258
259	down(&imlist_sem);
260	if (get_free_im_addr(size, &addr)) {
261	printk(KERN_ERR "%s() cannot obtain addr for size 0x%lx\n",
262	__FUNCTION__, size);
263	area = NULL;
264	goto next_im_done;
265	}
266
267	area = __im_get_area(addr, size, IM_REGION_UNUSED);
268	if (area == NULL) {
269	printk(KERN_ERR
270	"%s() cannot obtain area for addr 0x%lx size 0x%lx\n",
271	__FUNCTION__, addr, size);
272	}
273	next_im_done:
274	up(&imlist_sem);
275	return area;
276	}
277
278	struct vm_struct * im_get_area(unsigned long v_addr, unsigned long size,
279	int criteria)
280	{
281	struct vm_struct *area;
282
283	down(&imlist_sem);
284	area = __im_get_area(v_addr, size, criteria);
285	up(&imlist_sem);
286	return area;
287	}
288
20cee16c	289	void im_free(void * addr)
1da177e4 LT	290	{
1da177e4 LT	291	struct vm_struct *p, tmp;
1da177e4 LT	292
1da177e4 LT	293	if (!addr)
20cee16c DG	294	return;
20cee16c DG	295	if ((unsigned long) addr & ~PAGE_MASK) {
1da177e4	296	printk(KERN_ERR "Trying to %s bad address (%p)\n", __FUNCTION__, addr);
20cee16c	297	return;
1da177e4 LT	298	}
	299	down(&imlist_sem);
	300	for (p = &imlist ; (tmp = *p) ; p = &tmp->next) {
	301	if (tmp->addr == addr) {
1da177e4	302	*p = tmp->next;
20cee16c	303	unmap_vm_area(tmp);
1da177e4 LT	304	kfree(tmp);
1da177e4 LT	305	up(&imlist_sem);
20cee16c	306	return;
1da177e4 LT	307	}
	308	}
	309	up(&imlist_sem);
	310	printk(KERN_ERR "Trying to %s nonexistent area (%p)\n", __FUNCTION__,
	311	addr);
1da177e4	312	}