Re: [PATCH] [powerpc] Export memory limit via device tree

From: Suzuki K. Poulose
Date: Thu Jul 19 2012 - 04:01:16 EST

On 07/11/2012 11:06 AM, Benjamin Herrenschmidt wrote:
diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index c957b12..0c9695d 100644
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c
@@ -207,6 +207,12 @@ static struct property crashk_size_prop = {
.value = &crashk_size,

+static struct property memory_limit_prop = {
+ .name = "linux,memory-limit",
+ .length = sizeof(phys_addr_t),
+ .value = &memory_limit,

AFAIK. phys_addr_t can change size, so instead make it point to a known
fixes size quantity (a u64).

Sorry for the delay in the response.

Some of the other properties are also of phys_addr_t, (e.g linux,crashkernel-base, linux,kernel-end ). Should we fix them as well ?


Should we leave this also a phys_addr_t and let the userspace handle it ?

+ /* memory-limit is needed for constructing the crash regions */
+ prop = of_find_property(node,, NULL);
+ if (prop)
+ prom_remove_property(node, prop);
+ if (memory_limit)
+ prom_add_property(node, &memory_limit_prop);

There's a patch floating around making prom_update_property properly
handle both pre-existing and non-pre-existing props, you should probably
base yourself on top of it. I'm about to stick that patch in powerpc

OK. I am testing the new patch based on the above commit. I will wait
for the clarification on the issue of the type, before I post it here.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at