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

Sam Ravnborg
2018-12-03T16:29:16Z

Hi Mike.

> 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?

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

> 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.

Sam