Subject: [PATCH] powerpc: Feed entire flattened device tree into the random pool

From: Anton Blanchard <[email-masked]>
Date: Thu, 25 Jul 2013 12:51:22 +1000

We feed the entire DMI table into the random pool to provide
better random data during early boot, so do the same with the
flattened device tree.

Signed-off-by: Anton Blanchard <[email-masked]>
---

It might be worth doing this somewhere common, but the only place
I could find (unflatten_device_tree) is almost certainly too
early in the boot process.

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 63d051f..6914851 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -35,6 +35,7 @@
 #include <linux/percpu.h>
 #include <linux/memblock.h>
 #include <linux/of_platform.h>
+#include <linux/random.h>
 #include <asm/io.h>
 #include <asm/paca.h>
 #include <asm/prom.h>
@@ -752,3 +753,13 @@ void arch_setup_pdev_archdata(struct platform_device *pdev)
 	pdev->dev.dma_mask = &pdev->archdata.dma_mask;
  	set_dma_ops(&pdev->dev, &dma_direct_ops);
 }
+
+/* Feed entire flattened device tree into the random pool */
+static int __init add_fdt_randomness(void)
+{
+	add_device_randomness(initial_boot_params,
+			      initial_boot_params->totalsize);
+
+	return 0;
+}
+core_initcall(add_fdt_randomness);