[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>

17 files changed, 221 insertions, 217 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);