[POWERPC] Change rheap functions to use ulongs instead of pointers

The rheap allocation functions return a pointer, but the actual value is based
on how the heap was initialized, and so it can be anything, e.g. an offset
into a buffer.  A ulong is a better representation of the value returned by
the allocation functions.

This patch changes all of the relevant rheap functions to use a unsigned long
integers instead of a pointer.  In case of an error, the value returned is
a negative error code that has been cast to an unsigned long.  The caller can
use the IS_ERR_VALUE() macro to check for this.

All code which calls the rheap functions is updated accordingly.  Macros
IS_MURAM_ERR() and IS_DPERR(), have been deleted in favor of IS_ERR_VALUE().

Also added error checking to rh_attach_region().

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 67 insertions, 50 deletions

diff --git a/arch/powerpc/lib/rheap.c b/arch/powerpc/lib/rheap.c
index 6c5c5dd183ee..b2f6dcc59600 100644
--- a/arch/powerpc/lib/rheap.c
+++ b/arch/powerpc/lib/rheap.c
@@ -133,7 +133,7 @@ static rh_block_t *get_slot(rh_info_t * info)
         info->empty_slots--;
 
         /* Initialize */
-        blk->start = NULL;
+        blk->start = 0;
         blk->size = 0;
         blk->owner = NULL;
 
@@ -158,7 +158,7 @@ static void attach_free_block(rh_info_t * info, rh_block_t * blkn)
 
         /* We assume that they are aligned properly */
         size = blkn->size;
-        s = (unsigned long)blkn->start;
+        s = blkn->start;
         e = s + size;
 
         /* Find the blocks immediately before and after the given one
@@ -170,7 +170,7 @@ static void attach_free_block(rh_info_t * info, rh_block_t * blkn)
         list_for_each(l, &info->free_list) {
                 blk = list_entry(l, rh_block_t, list);
 
-                bs = (unsigned long)blk->start;
+                bs = blk->start;
                 be = bs + blk->size;
 
                 if (next == NULL && s >= bs)
@@ -188,10 +188,10 @@ static void attach_free_block(rh_info_t * info, rh_block_t * blkn)
         }
 
         /* Now check if they are really adjacent */
-        if (before != NULL && s != (unsigned long)before->start + before->size)
+        if (before && s != (before->start + before->size))
                 before = NULL;
 
-        if (after != NULL && e != (unsigned long)after->start)
+        if (after && e != after->start)
                 after = NULL;
 
         /* No coalescing; list insert and return */
@@ -216,7 +216,7 @@ static void attach_free_block(rh_info_t * info, rh_block_t * blkn)
 
         /* Grow the after block backwards */
         if (before == NULL && after != NULL) {
-                after->start = (int8_t *)after->start - size;
+                after->start -= size;
                 after->size += size;
                 return;
         }
@@ -321,14 +321,14 @@ void rh_init(rh_info_t * info, unsigned int alignment, int max_blocks,
 }
 
 /* Attach a free memory region, coalesces regions if adjuscent */
-int rh_attach_region(rh_info_t * info, void *start, int size)
+int rh_attach_region(rh_info_t * info, unsigned long start, int size)
 {
         rh_block_t *blk;
         unsigned long s, e, m;
         int r;
 
         /* The region must be aligned */
-        s = (unsigned long)start;
+        s = start;
         e = s + size;
         m = info->alignment - 1;
 
@@ -338,9 +338,12 @@ int rh_attach_region(rh_info_t * info, void *start, int size)
         /* Round end down */
         e = e & ~m;
 
+        if (IS_ERR_VALUE(e) || (e < s))
+                return -ERANGE;
+
         /* Take final values */
-        start = (void *)s;
-        size = (int)(e - s);
+        start = s;
+        size = e - s;
 
         /* Grow the blocks, if needed */
         r = assure_empty(info, 1);
@@ -358,7 +361,7 @@ int rh_attach_region(rh_info_t * info, void *start, int size)
 }
 
 /* Detatch given address range, splits free block if needed. */
-void *rh_detach_region(rh_info_t * info, void *start, int size)
+unsigned long rh_detach_region(rh_info_t * info, unsigned long start, int size)
 {
         struct list_head *l;
         rh_block_t *blk, *newblk;
@@ -366,10 +369,10 @@ void *rh_detach_region(rh_info_t * info, void *start, int size)
 
         /* Validate size */
         if (size <= 0)
-                return ERR_PTR(-EINVAL);
+                return (unsigned long) -EINVAL;
 
         /* The region must be aligned */
-        s = (unsigned long)start;
+        s = start;
         e = s + size;
         m = info->alignment - 1;
 
@@ -380,34 +383,34 @@ void *rh_detach_region(rh_info_t * info, void *start, int size)
         e = e & ~m;
 
         if (assure_empty(info, 1) < 0)
-                return ERR_PTR(-ENOMEM);
+                return (unsigned long) -ENOMEM;
 
         blk = NULL;
         list_for_each(l, &info->free_list) {
                 blk = list_entry(l, rh_block_t, list);
                 /* The range must lie entirely inside one free block */
-                bs = (unsigned long)blk->start;
-                be = (unsigned long)blk->start + blk->size;
+                bs = blk->start;
+                be = blk->start + blk->size;
                 if (s >= bs && e <= be)
                         break;
                 blk = NULL;
         }
 
         if (blk == NULL)
-                return ERR_PTR(-ENOMEM);
+                return (unsigned long) -ENOMEM;
 
         /* Perfect fit */
         if (bs == s && be == e) {
                 /* Delete from free list, release slot */
                 list_del(&blk->list);
                 release_slot(info, blk);
-                return (void *)s;
+                return s;
         }
 
         /* blk still in free list, with updated start and/or size */
         if (bs == s || be == e) {
                 if (bs == s)
-                        blk->start = (int8_t *)blk->start + size;
+                        blk->start += size;
                 blk->size -= size;
 
         } else {
@@ -416,25 +419,29 @@ void *rh_detach_region(rh_info_t * info, void *start, int size)
 
                 /* the back free fragment */
                 newblk = get_slot(info);
-                newblk->start = (void *)e;
+                newblk->start = e;
                 newblk->size = be - e;
 
                 list_add(&newblk->list, &blk->list);
         }
 
-        return (void *)s;
+        return s;
 }
 
-void *rh_alloc_align(rh_info_t * info, int size, int alignment, const char *owner)
+/* Allocate a block of memory at the specified alignment.  The value returned
+ * is an offset into the buffer initialized by rh_init(), or a negative number
+ * if there is an error.
+ */
+unsigned long rh_alloc_align(rh_info_t * info, int size, int alignment, const char *owner)
 {
         struct list_head *l;
         rh_block_t *blk;
         rh_block_t *newblk;
-        void *start;
+        unsigned long start;
 
-        /* Validate size, (must be power of two) */
+        /* Validate size, and alignment must be power of two */
         if (size <= 0 || (alignment & (alignment - 1)) != 0)
-                return ERR_PTR(-EINVAL);
+                return (unsigned long) -EINVAL;
 
         /* given alignment larger that default rheap alignment */
         if (alignment > info->alignment)
@@ -444,7 +451,7 @@ void *rh_alloc_align(rh_info_t * info, int size, int alignment, const char *owne
         size = (size + (info->alignment - 1)) & ~(info->alignment - 1);
 
         if (assure_empty(info, 1) < 0)
-                return ERR_PTR(-ENOMEM);
+                return (unsigned long) -ENOMEM;
 
         blk = NULL;
         list_for_each(l, &info->free_list) {
@@ -455,7 +462,7 @@ void *rh_alloc_align(rh_info_t * info, int size, int alignment, const char *owne
         }
 
         if (blk == NULL)
-                return ERR_PTR(-ENOMEM);
+                return (unsigned long) -ENOMEM;
 
         /* Just fits */
         if (blk->size == size) {
@@ -475,7 +482,7 @@ void *rh_alloc_align(rh_info_t * info, int size, int alignment, const char *owne
         newblk->owner = owner;
 
         /* blk still in free list, with updated start, size */
-        blk->start = (int8_t *)blk->start + size;
+        blk->start += size;
         blk->size -= size;
 
         start = newblk->start;
@@ -486,19 +493,25 @@ void *rh_alloc_align(rh_info_t * info, int size, int alignment, const char *owne
         /* this is no problem with the deallocator since */
         /* we scan for pointers that lie in the blocks   */
         if (alignment > info->alignment)
-                start = (void *)(((unsigned long)start + alignment - 1) &
-                                ~(alignment - 1));
+                start = (start + alignment - 1) & ~(alignment - 1);
 
         return start;
 }
 
-void *rh_alloc(rh_info_t * info, int size, const char *owner)
+/* Allocate a block of memory at the default alignment.  The value returned is
+ * an offset into the buffer initialized by rh_init(), or a negative number if
+ * there is an error.
+ */
+unsigned long rh_alloc(rh_info_t * info, int size, const char *owner)
 {
         return rh_alloc_align(info, size, info->alignment, owner);
 }
 
-/* allocate at precisely the given address */
-void *rh_alloc_fixed(rh_info_t * info, void *start, int size, const char *owner)
+/* Allocate a block of memory at the given offset, rounded up to the default
+ * alignment.  The value returned is an offset into the buffer initialized by
+ * rh_init(), or a negative number if there is an error.
+ */
+unsigned long rh_alloc_fixed(rh_info_t * info, unsigned long start, int size, const char *owner)
 {
         struct list_head *l;
         rh_block_t *blk, *newblk1, *newblk2;
@@ -506,10 +519,10 @@ void *rh_alloc_fixed(rh_info_t * info, void *start, int size, const char *owner)
 
         /* Validate size */
         if (size <= 0)
-                return ERR_PTR(-EINVAL);
+                return (unsigned long) -EINVAL;
 
         /* The region must be aligned */
-        s = (unsigned long)start;
+        s = start;
         e = s + size;
         m = info->alignment - 1;
 
@@ -520,20 +533,20 @@ void *rh_alloc_fixed(rh_info_t * info, void *start, int size, const char *owner)
         e = e & ~m;
 
         if (assure_empty(info, 2) < 0)
-                return ERR_PTR(-ENOMEM);
+                return (unsigned long) -ENOMEM;
 
         blk = NULL;
         list_for_each(l, &info->free_list) {
                 blk = list_entry(l, rh_block_t, list);
                 /* The range must lie entirely inside one free block */
-                bs = (unsigned long)blk->start;
-                be = (unsigned long)blk->start + blk->size;
+                bs = blk->start;
+                be = blk->start + blk->size;
                 if (s >= bs && e <= be)
                         break;
         }
 
         if (blk == NULL)
-                return ERR_PTR(-ENOMEM);
+                return (unsigned long) -ENOMEM;
 
         /* Perfect fit */
         if (bs == s && be == e) {
@@ -551,7 +564,7 @@ void *rh_alloc_fixed(rh_info_t * info, void *start, int size, const char *owner)
         /* blk still in free list, with updated start and/or size */
         if (bs == s || be == e) {
                 if (bs == s)
-                        blk->start = (int8_t *)blk->start + size;
+                        blk->start += size;
                 blk->size -= size;
 
         } else {
@@ -560,14 +573,14 @@ void *rh_alloc_fixed(rh_info_t * info, void *start, int size, const char *owner)
 
                 /* The back free fragment */
                 newblk2 = get_slot(info);
-                newblk2->start = (void *)e;
+                newblk2->start = e;
                 newblk2->size = be - e;
 
                 list_add(&newblk2->list, &blk->list);
         }
 
         newblk1 = get_slot(info);
-        newblk1->start = (void *)s;
+        newblk1->start = s;
         newblk1->size = e - s;
         newblk1->owner = owner;
 
@@ -577,7 +590,11 @@ void *rh_alloc_fixed(rh_info_t * info, void *start, int size, const char *owner)
         return start;
 }
 
-int rh_free(rh_info_t * info, void *start)
+/* Deallocate the memory previously allocated by one of the rh_alloc functions.
+ * The return value is the size of the deallocated block, or a negative number
+ * if there is an error.
+ */
+int rh_free(rh_info_t * info, unsigned long start)
 {
         rh_block_t *blk, *blk2;
         struct list_head *l;
@@ -642,7 +659,7 @@ int rh_get_stats(rh_info_t * info, int what, int max_stats, rh_stats_t * stats)
         return nr;
 }
 
-int rh_set_owner(rh_info_t * info, void *start, const char *owner)
+int rh_set_owner(rh_info_t * info, unsigned long start, const char *owner)
 {
         rh_block_t *blk, *blk2;
         struct list_head *l;
@@ -684,8 +701,8 @@ void rh_dump(rh_info_t * info)
                 nr = maxnr;
         for (i = 0; i < nr; i++)
                 printk(KERN_INFO
-                       "    0x%p-0x%p (%u)\n",
-                       st[i].start, (int8_t *) st[i].start + st[i].size,
+                       "    0x%lx-0x%lx (%u)\n",
+                       st[i].start, st[i].start + st[i].size,
                        st[i].size);
         printk(KERN_INFO "\n");
 
@@ -695,8 +712,8 @@ void rh_dump(rh_info_t * info)
                 nr = maxnr;
         for (i = 0; i < nr; i++)
                 printk(KERN_INFO
-                       "    0x%p-0x%p (%u) %s\n",
-                       st[i].start, (int8_t *) st[i].start + st[i].size,
+                       "    0x%lx-0x%lx (%u) %s\n",
+                       st[i].start, st[i].start + st[i].size,
                        st[i].size, st[i].owner != NULL ? st[i].owner : "");
         printk(KERN_INFO "\n");
 }
@@ -704,6 +721,6 @@ void rh_dump(rh_info_t * info)
 void rh_dump_blk(rh_info_t * info, rh_block_t * blk)
 {
         printk(KERN_INFO
-               "blk @0x%p: 0x%p-0x%p (%u)\n",
-               blk, blk->start, (int8_t *) blk->start + blk->size, blk->size);
+               "blk @0x%p: 0x%lx-0x%lx (%u)\n",
+               blk, blk->start, blk->start + blk->size, blk->size);
 }