[PATCH] powerpc: Always panic if lmb_alloc() fails

Currently most callers of lmb_alloc() don't check if it worked or not, if it
ever does weird bad things will probably happen. The few callers who do check
just panic or BUG_ON.

So make lmb_alloc() panic internally, to catch bugs at the source. The few
callers who did check the result no longer need to.

The only caller that did anything interesting with the return result was
careful_allocation(). For it we create __lmb_alloc_base() which _doesn't_ panic
automatically, a little messy, but passable.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

7 files changed, 16 insertions, 14 deletions

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 294832a7e0a6..82d117c60d7f 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -831,10 +831,6 @@ void __init unflatten_device_tree(void)
 
         /* Allocate memory for the expanded device tree */
         mem = lmb_alloc(size + 4, __alignof__(struct device_node));
-        if (!mem) {
-                DBG("Couldn't allocate memory with lmb_alloc()!\n");
-                panic("Couldn't allocate memory with lmb_alloc()!\n");
-        }
         mem = (unsigned long) __va(mem);
 
         ((u32 *)mem)[size / 4] = 0xdeadbeef;
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 149351a84b94..95b4cd6b65e0 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -430,7 +430,6 @@ void __init htab_initialize(void)
                  * the absolute address space.
                  */
                 table = lmb_alloc(htab_size_bytes, htab_size_bytes);
-                BUG_ON(table == 0);
 
                 DBG("Hash table allocated at %lx, size: %lx\n", table,
                     htab_size_bytes);
diff --git a/arch/powerpc/mm/lmb.c b/arch/powerpc/mm/lmb.c
index bbe3eac918e8..d9c76ce5fa8f 100644
--- a/arch/powerpc/mm/lmb.c
+++ b/arch/powerpc/mm/lmb.c
@@ -226,6 +226,20 @@ unsigned long __init lmb_alloc(unsigned long size, unsigned long align)
 unsigned long __init lmb_alloc_base(unsigned long size, unsigned long align,
                                     unsigned long max_addr)
 {
+        unsigned long alloc;
+
+        alloc = __lmb_alloc_base(size, align, max_addr);
+
+        if (alloc < 0)
+                panic("ERROR: Failed to allocate 0x%lx bytes below 0x%lx.\n",
+                                size, max_addr);
+
+        return alloc;
+}
+
+unsigned long __init __lmb_alloc_base(unsigned long size, unsigned long align,
+                                    unsigned long max_addr)
+{
         long i, j;
         unsigned long base = 0;
 
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 550517c2dd42..6809cdba6e94 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -249,7 +249,6 @@ void __init do_init_bootmem(void)
         bootmap_pages = bootmem_bootmap_pages(total_pages);
 
         start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
-        BUG_ON(!start);
 
         boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
 
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 2863a912bcd0..da5280f8cf42 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -570,11 +570,11 @@ static void __init *careful_allocation(int nid, unsigned long size,
                                        unsigned long end_pfn)
 {
         int new_nid;
-        unsigned long ret = lmb_alloc_base(size, align, end_pfn << PAGE_SHIFT);
+        unsigned long ret = __lmb_alloc_base(size, align, end_pfn << PAGE_SHIFT);
 
         /* retry over all memory */
         if (!ret)
-                ret = lmb_alloc_base(size, align, lmb_end_of_DRAM());
+                ret = __lmb_alloc_base(size, align, lmb_end_of_DRAM());
 
         if (!ret)
                 panic("numa.c: cannot allocate %lu bytes on node %d",
diff --git a/arch/powerpc/mm/stab.c b/arch/powerpc/mm/stab.c
index 82e4951826bc..91d25fb27f89 100644
--- a/arch/powerpc/mm/stab.c
+++ b/arch/powerpc/mm/stab.c
@@ -247,10 +247,6 @@ void stabs_alloc(void)
 
                 newstab = lmb_alloc_base(HW_PAGE_SIZE, HW_PAGE_SIZE,
                                          1<<SID_SHIFT);
-                if (! newstab)
-                        panic("Unable to allocate segment table for CPU %d.\n",
-                              cpu);
-
                 newstab = (unsigned long)__va(newstab);
 
                 memset((void *)newstab, 0, HW_PAGE_SIZE);
diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 977de9db8754..929ad2333aab 100644
--- a/arch/powerpc/sysdev/dart_iommu.c
+++ b/arch/powerpc/sysdev/dart_iommu.c
@@ -194,8 +194,6 @@ static int dart_init(struct device_node *dart_node)
          * prefetching into invalid pages and corrupting data
          */
         tmp = lmb_alloc(DART_PAGE_SIZE, DART_PAGE_SIZE);
-        if (!tmp)
-                panic("DART: Cannot allocate spare page!");
         dart_emptyval = DARTMAP_VALID | ((tmp >> DART_PAGE_SHIFT) &
                                          DARTMAP_RPNMASK);