On Mon, Dec 03, 2018 at 05:29:08PM +0100, Sam Ravnborg wrote:

Hi Mike.

quoted

index c37955d..2a17665 100644

--- a/arch/sparc/kernel/prom_64.c
+++ b/arch/sparc/kernel/prom_64.c

@@ -34,16 +34,13 @@
 
 void * __init prom_early_alloc(unsigned long size)
 {
-	unsigned long paddr = memblock_phys_alloc(size, SMP_CACHE_BYTES);
-	void *ret;
+	void *ret = memblock_alloc(size, SMP_CACHE_BYTES);
 
-	if (!paddr) {
+	if (!ret) {
 		prom_printf("prom_early_alloc(%lu) failed\n", size);
 		prom_halt();
 	}
 
-	ret = __va(paddr);
-	memset(ret, 0, size);
 	prom_early_allocated += size;
 
 	return ret;

memblock_alloc() calls memblock_alloc_try_nid().
And if allocation fails then memblock_alloc_try_nid() calls panic().
So will we ever hit the prom_halt() code?

memblock_phys_alloc_try_nid() also calls panic if an allocation fails. So
in either case we never reach prom_halt() code.

Actually, sparc is rather an exception from the general practice to rely on
panic() inside the early allocator rather than to check the return value.
 

Do we have a panic() implementation that actually returns?

quoted

diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 3c8aac2..52884f4 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c

@@ -1089,16 +1089,13 @@ static void __init allocate_node_data(int nid)
 	struct pglist_data *p;
 	unsigned long start_pfn, end_pfn;
 #ifdef CONFIG_NEED_MULTIPLE_NODES
-	unsigned long paddr;
 
-	paddr = memblock_phys_alloc_try_nid(sizeof(struct pglist_data),
-					    SMP_CACHE_BYTES, nid);
-	if (!paddr) {
+	NODE_DATA(nid) = memblock_alloc_node(sizeof(struct pglist_data),
+					     SMP_CACHE_BYTES, nid);
+	if (!NODE_DATA(nid)) {
 		prom_printf("Cannot allocate pglist_data for nid[%d]\n", nid);
 		prom_halt();
 	}
-	NODE_DATA(nid) = __va(paddr);
-	memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));
 
 	NODE_DATA(nid)->node_id = nid;
 #endif

Same here.

I did not look at the other cases.

I really tried to be careful and did the replacements only for the calls
that do panic if an allocation fails.
 

	Sam

-- 
Sincerely yours,
Mike.


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