powerpc/mm: Fix memory_block_size_bytes() for non-pseries

Just compiling pseries in the kernel causes it to override
memory_block_size_bytes() regardless of what is the runtime

This cleans up the implementation of that function, fixing
a bug or two while at it, so that it's harmless (and potentially
useful) for other platforms. Without this, bugs in that code
would trigger a WARN_ON() in drivers/base/memory.c when
booting some different platforms.

If/when we have another platform supporting memory hotplug we
might want to either move that out to a generic place or
make it a ppc_md. callback.
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent a63fdc51
......@@ -12,6 +12,8 @@
#include <linux/of.h>
#include <linux/memblock.h>
#include <linux/vmalloc.h>
#include <linux/memory.h>
#include <asm/firmware.h>
#include <asm/machdep.h>
#include <asm/pSeries_reconfig.h>
......@@ -20,24 +22,25 @@
static unsigned long get_memblock_size(void)
struct device_node *np;
unsigned int memblock_size = 0;
unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
struct resource r;
np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
if (np) {
const unsigned long *size;
const __be64 *size;
size = of_get_property(np, "ibm,lmb-size", NULL);
memblock_size = size ? *size : 0;
if (size)
memblock_size = be64_to_cpup(size);
} else {
} else if (machine_is(pseries)) {
/* This fallback really only applies to pseries */
unsigned int memzero_size = 0;
const unsigned int *regs;
np = of_find_node_by_path("/memory@0");
if (np) {
regs = of_get_property(np, "reg", NULL);
memzero_size = regs ? regs[3] : 0;
if (!of_address_to_resource(np, 0, &r))
memzero_size = resource_size(&r);
......@@ -50,16 +53,21 @@ static unsigned long get_memblock_size(void)
sprintf(buf, "/memory@%x", memzero_size);
np = of_find_node_by_path(buf);
if (np) {
regs = of_get_property(np, "reg", NULL);
memblock_size = regs ? regs[3] : 0;
if (!of_address_to_resource(np, 0, &r))
memblock_size = resource_size(&r);
return memblock_size;
/* WARNING: This is going to override the generic definition whenever
* pseries is built-in regardless of what platform is active at boot
* time. This is fine for now as this is the only "option" and it
* should work everywhere. If not, we'll have to turn this into a
* ppc_md. callback
unsigned long memory_block_size_bytes(void)
return get_memblock_size();
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