[PATCH 1/2] pseries: phyp dump: Disable phyp-dump through boot-var.

[Manish Ahuja <ahuja@austin.ibm.com>]

The goal of these 2 patches is to ensure that there is only one dumping
mechanism enabled at any given time. These patches depend upon phyp-dump
patches posted earlier.

Patch 1:

Addition of boot-variable "phyp_dump", which takes values [0/1] for disabling/
enabling phyp_dump at boot time. Kdump can use this on cmdline (phyp_dump=0) 
to disable phyp-dump during boot when enabling itself. This will ensure only
one dumping mechanism is active at any given time.

Signed-off-by: Manish Ahuja <mahuja@us.ibm.com>

---
 arch/powerpc/kernel/prom.c                 |    5 +++++
 arch/powerpc/platforms/pseries/phyp_dump.c |   18 ++++++++++++++++++
 include/asm-powerpc/phyp_dump.h            |    1 +
 3 files changed, 24 insertions(+)

Index: 2.6.25-rc1/arch/powerpc/platforms/pseries/phyp_dump.c
===================================================================
--- 2.6.25-rc1.orig/arch/powerpc/platforms/pseries/phyp_dump.c	2008-03-22 00:42:02.000000000 -0500
+++ 2.6.25-rc1/arch/powerpc/platforms/pseries/phyp_dump.c	2008-03-22 01:07:43.000000000 -0500
@@ -460,3 +460,21 @@ int __init early_init_dt_scan_phyp_dump(
 						*((unsigned long *)&sizes[4]);
 	return 1;
 }
+
+/* Look for phyp_dump= cmdline option */
+static int __init early_phyp_dump_enabled(char *p)
+{
+	phyp_dump_info->phyp_dump_at_boot = 1;
+
+        if (!p)
+                return 0;
+
+        if (strncmp(p, "1", 1) == 0)
+		phyp_dump_info->phyp_dump_at_boot = 1;
+        else if (strncmp(p, "0", 1) == 0)
+		phyp_dump_info->phyp_dump_at_boot = 0;
+
+        return 0;
+}
+early_param("phyp_dump", early_phyp_dump_enabled);
+
Index: 2.6.25-rc1/include/asm-powerpc/phyp_dump.h
===================================================================
--- 2.6.25-rc1.orig/include/asm-powerpc/phyp_dump.h	2008-03-22 00:42:02.000000000 -0500
+++ 2.6.25-rc1/include/asm-powerpc/phyp_dump.h	2008-03-22 00:42:08.000000000 -0500
@@ -25,6 +25,7 @@ struct phyp_dump {
 	unsigned long init_reserve_start;
 	unsigned long init_reserve_size;
 	/* Check status during boot if dump supported, active & present*/
+	unsigned long phyp_dump_at_boot;
 	unsigned long phyp_dump_configured;
 	unsigned long phyp_dump_is_active;
 	/* store cpu & hpte size */
Index: 2.6.25-rc1/arch/powerpc/kernel/prom.c
===================================================================
--- 2.6.25-rc1.orig/arch/powerpc/kernel/prom.c	2008-03-22 00:42:02.000000000 -0500
+++ 2.6.25-rc1/arch/powerpc/kernel/prom.c	2008-03-22 00:42:54.000000000 -0500
@@ -1059,6 +1059,11 @@ static void __init phyp_dump_reserve_mem
 		return;
 	}
 
+	if (!phyp_dump_info->phyp_dump_at_boot) {
+		printk(KERN_INFO "Phyp-dump disabled at boot time\n");
+		return;
+	}
+
 	if (phyp_dump_info->phyp_dump_is_active) {
 		/* Reserve *everything* above RMR.Area freed by userland tools*/
 		base = PHYP_DUMP_RMR_END;