From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hsin-Yi Wang Subject: [PATCH v6 2/3] fdt: add support for rng-seed Date: Wed, 12 Jun 2019 12:33:00 +0800 Message-ID: <20190612043258.166048-3-hsinyi@chromium.org> References: <20190612043258.166048-1-hsinyi@chromium.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190612043258.166048-1-hsinyi@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-arm-kernel@lists.infradead.org Cc: Rob Herring , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Frank Rowand , Catalin Marinas , Will Deacon , Andrew Morton , Mike Rapoport , Ard Biesheuvel , Miles Chen , Hsin-Yi Wang , James Morse , Andrew Murray , Mark Rutland , Jun Yao , Yu Zhao , Robin Murphy , Laura Abbott , Stephen Boyd , Kees Cook List-Id: devicetree@vger.kernel.org Introducing a chosen node, rng-seed, which is an entropy that can be passed to kernel called very early to increase initial device randomness. Bootloader should provide this entropy and the value is read from /chosen/rng-seed in DT. Signed-off-by: Hsin-Yi Wang Reviewed-by: Stephen Boyd --- change log v5->v6: * remove Documentation change --- drivers/of/fdt.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 3d36b5afd9bd..369130dbd42c 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -24,6 +24,7 @@ #include #include #include +#include #include /* for COMMAND_LINE_SIZE */ #include @@ -1052,6 +1053,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, { int l; const char *p; + const void *rng_seed; pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); @@ -1086,6 +1088,14 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, pr_debug("Command line is: %s\n", (char*)data); + rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); + if (rng_seed && l > 0) { + add_device_randomness(rng_seed, l); + + /* try to clear seed so it won't be found. */ + fdt_nop_property(initial_boot_params, node, "rng-seed"); + } + /* break now */ return 1; } -- 2.20.1