lmb: Return -EFAULT when freeing unallocated memory regions

Make lmb_free() return -EFAULT when the requested memory region is not
allocated, instead of the generic -1 error value.

Document the updated error code in the public API comment and change the
LMB unit test to check for the new -EFAULT errno value.

Signed-off-by: Jonas Karlman <[email protected]>
Reviewed-by: Randolph Sapp <[email protected]>

3 files changed, 4 insertions, 2 deletions

diff --git a/include/lmb.h b/include/lmb.h
index 028dabb19e8..157a24baf97 100644
--- a/include/lmb.h
+++ b/include/lmb.h
@@ -168,6 +168,8 @@ int lmb_is_reserved_flags(phys_addr_t addr, int flags);
  * @flags: Memory region attributes
  *
  * Return: 0 on success, negative error code on failure.
+ *
+ * The return value can be -EFAULT when the region has not been allocated.
  */
 long lmb_free(phys_addr_t base, phys_size_t size, u32 flags);
 
diff --git a/lib/lmb.c b/lib/lmb.c
index f7c2e826d06..ca00047f624 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -286,7 +286,7 @@ static long _lmb_free(struct alist *lmb_rgn_lst, phys_addr_t base,
 
 	/* Didn't find the region */
 	if (i == lmb_rgn_lst->count)
-		return -1;
+		return -EFAULT;
 
 	/* Check to see if we are removing entire region */
 	if (rgnbegin == base && rgnend == end) {
diff --git a/test/lib/lmb.c b/test/lib/lmb.c
index b93b903f99f..168c66ae649 100644
--- a/test/lib/lmb.c
+++ b/test/lib/lmb.c
@@ -477,7 +477,7 @@ static int lib_test_lmb_at_0(struct unit_test_state *uts)
 		   0, 0, 0, 0);
 	/* check that this was an error by freeing b */
 	ret = lmb_free(b, 4, LMB_NONE);
-	ut_asserteq(ret, -1);
+	ut_asserteq(ret, -EFAULT);
 	ASSERT_LMB(mem_lst, used_lst, ram, ram_size, 1, a, ram_size - 4,
 		   0, 0, 0, 0);