1 files changed, 312 insertions, 0 deletions
diff --git a/arch/ppc64/mm/imalloc.c b/arch/ppc64/mm/imalloc.c
new file mode 100644
index 000000000000..9d92b0d9cde5
--- /dev/null
+++ b/arch/ppc64/mm/imalloc.c
@@ -0,0 +1,312 @@
+/*
+ * 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>
+
+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 = IMALLOC_START;
+	for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
+		if (size + addr < (unsigned long) tmp->addr)
+			break;
+		if ((unsigned long)tmp->addr >= IMALLOC_START) 
+			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;
+}
+
+unsigned long im_free(void * addr)
+{
+	struct vm_struct **p, *tmp;
+	unsigned long ret_size = 0;
+  
+	if (!addr)
+		return ret_size;
+	if ((PAGE_SIZE-1) & (unsigned long) addr) {
+		printk(KERN_ERR "Trying to %s bad address (%p)\n", __FUNCTION__,			addr);
+		return ret_size;
+	}
+	down(&imlist_sem);
+	for (p = &imlist ; (tmp = *p) ; p = &tmp->next) {
+		if (tmp->addr == addr) {
+			ret_size = tmp->size;
+			*p = tmp->next;
+			kfree(tmp);
+			up(&imlist_sem);
+			return ret_size;
+		}
+	}
+	up(&imlist_sem);
+	printk(KERN_ERR "Trying to %s nonexistent area (%p)\n", __FUNCTION__,
+			addr);
+	return ret_size;
+}