[PATCH V4] powerpc/prom: Export device tree physical address via proc
Matthew McClintock
msm at freescale.com
Thu Jul 15 01:18:53 EST 2010
To build a proper flat device tree for kexec we need to know which
memreserve region was used for the device tree for the currently
running kernel, so we can remove it and replace it with the new
memreserve for the kexec'ed kernel
Signed-off-by: Matthew McClintock <msm at freescale.com>
---
V4: Fixed misspelling
V3: Remove unneeded cast, and fixed indentation screw up
V2: messed up changes
arch/powerpc/kernel/prom.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 45 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index fd9359a..ff3e240 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -32,6 +32,7 @@
#include <linux/debugfs.h>
#include <linux/irq.h>
#include <linux/lmb.h>
+#include <linux/bootmem.h>
#include <asm/prom.h>
#include <asm/rtas.h>
@@ -911,3 +912,47 @@ static int __init export_flat_device_tree(void)
}
__initcall(export_flat_device_tree);
#endif
+
+#ifdef CONFIG_KEXEC
+static phys_addr_t flat_dt_start;
+static phys_addr_t flat_dt_end;
+
+static struct property flat_dt_start_prop = {
+ .name = "linux,devicetree-start",
+ .length = sizeof(phys_addr_t),
+ .value = &flat_dt_start,
+};
+
+static struct property flat_dt_end_prop = {
+ .name = "linux,devicetree-end",
+ .length = sizeof(phys_addr_t),
+ .value = &flat_dt_end,
+};
+
+static int __init export_flat_device_tree_phys_addr(void)
+{
+ struct property *prop;
+ struct device_node *node;
+
+ node = of_find_node_by_path("/chosen");
+ if (!node)
+ return -ENOENT;
+
+ prop = of_find_property(node, "linux,devicetree-start", NULL);
+ if (prop)
+ prom_remove_property(node, prop);
+
+ prop = of_find_property(node, "linux,devicetree-end", NULL);
+ if (prop)
+ prom_remove_property(node, prop);
+
+ flat_dt_start = virt_to_phys(initial_boot_params);
+ flat_dt_end = virt_to_phys(initial_boot_params)
+ + initial_boot_params->totalsize;
+ prom_add_property(node, &flat_dt_start_prop);
+ prom_add_property(node, &flat_dt_end_prop);
+
+ return 0;
+}
+__initcall(export_flat_device_tree_phys_addr);
+#endif
--
1.6.6.1
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