Re: [PATCH v2 5/6] arch: simplify several early memory allocations

On Mon, Dec 03, 2018 at 06:49:21PM +0200, Mike Rapoport wrote:

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

quoted

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.

So we have code here we never reach - not nice.
If the idea is to avoid relying on the panic inside memblock_alloc() then
maybe replace it with a variant that do not call panic?
To make it clear what happens.

	Sam