Thread (14 messages) 14 messages, 4 authors, 2013-09-04

[PATCH v4 1/5] ARM: add basic Trusted Foundations support

From: Tomasz Figa <hidden>
Date: 2013-08-30 08:20:53
Also in: linux-devicetree, linux-tegra, lkml 

Hi Alexandre,

Overall this looks good to me, but I have some minor comments.

On Thursday 29 of August 2013 18:57:44 Alexandre Courbot wrote:
quoted hunk ↗ jump to hunk
Trusted Foundations is a TrustZone-based secure monitor for ARM that
can be invoked  using a consistent smc-based API on all supported
platforms. This patch adds initial basic support for Trusted
Foundations using the ARM firmware API. Current features are limited
to the ability to boot secondary processors.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 .../arm/firmware/tl,trusted-foundations.txt        | 17 +++++
 .../devicetree/bindings/vendor-prefixes.txt        |  1 +
 arch/arm/Kconfig                                   |  2 +
 arch/arm/Makefile                                  |  1 +
 arch/arm/firmware/Kconfig                          | 26 +++++++
 arch/arm/firmware/Makefile                         |  1 +
 arch/arm/firmware/trusted_foundations.c            | 83
++++++++++++++++++++++ arch/arm/include/asm/trusted_foundations.h      
  | 48 +++++++++++++ 8 files changed, 179 insertions(+)
 create mode 100644
Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.t
xt create mode 100644 arch/arm/firmware/Kconfig
 create mode 100644 arch/arm/firmware/Makefile
 create mode 100644 arch/arm/firmware/trusted_foundations.c
 create mode 100644 arch/arm/include/asm/trusted_foundations.h

diff --git
a/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations
.txt
b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations
.txt new file mode 100644
index 0000000..3954bbd
--- /dev/null
+++
b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations
.txt @@ -0,0 +1,17 @@
+Trusted Foundations
+
+Boards that use the Trusted Foundations secure monitor can signal its
+presence by declaring a node compatible with "tl,trusted-foundations"
+under the root node.
+
+Required properties:
+- compatible : "tl,trusted-foundations"
+- version-major : major version number of Trusted Foundations firmware
+- version-minor: minor version number of Trusted Foundations firmware
Hmm, maybe you could simply define a single version property that could 
have multiple cells? Like:

	firmware {
		compatible = "tl,trusted-foundations";
		version = <2 8>;
	};
quoted hunk ↗ jump to hunk
+Example:
+	firmware {
+		compatible = "tl,trusted-foundations";
+		version-major = <2>;
+		version-minor = <8>;
+	};
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt
b/Documentation/devicetree/bindings/vendor-prefixes.txt index
366ce9b..20d61f3 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -63,6 +63,7 @@ ste	ST-Ericsson
 stericsson	ST-Ericsson
 toumaz	Toumaz
 ti	Texas Instruments
+tl	Trusted Logic
 toshiba	Toshiba Corporation
 v3	V3 Semiconductor
 via	VIA Technologies, Inc.
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 43594d5..7fbe800 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1074,6 +1074,8 @@ config ARM_TIMER_SP804
 	select CLKSRC_MMIO
 	select CLKSRC_OF if OF

+source "arch/arm/firmware/Kconfig"
+
 source arch/arm/mm/Kconfig

 config ARM_NR_BANKS
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 6fd2cea..a48de17 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -267,6 +267,7 @@ core-$(CONFIG_KVM_ARM_HOST) 	+= arch/arm/kvm/
 core-y				+= arch/arm/kernel/ arch/arm/mm/ 
arch/arm/common/
quoted hunk ↗ jump to hunk
 core-y				+= arch/arm/net/
 core-y				+= arch/arm/crypto/
+core-y				+= arch/arm/firmware/
 core-y				+= $(machdirs) $(platdirs)

 drivers-$(CONFIG_OPROFILE)      += arch/arm/oprofile/
diff --git a/arch/arm/firmware/Kconfig b/arch/arm/firmware/Kconfig
new file mode 100644
index 0000000..fde21d0
--- /dev/null
+++ b/arch/arm/firmware/Kconfig
@@ -0,0 +1,26 @@
+config ARCH_SUPPORTS_FIRMWARE
+	bool
+
+config ARCH_SUPPORTS_TRUSTED_FOUNDATIONS
+	bool
+	select ARCH_SUPPORTS_FIRMWARE
+
+menu "Firmware options"
+	depends on ARCH_SUPPORTS_FIRMWARE
+
+config TRUSTED_FOUNDATIONS
+	bool "Trusted Foundations secure monitor support"
+	depends on ARCH_SUPPORTS_TRUSTED_FOUNDATIONS
+	help
+	  Some devices are booted with the Trusted Foundations secure 
monitor
+	  active, requiring some core operations to be performed by the 
secure
+	  monitor instead of the kernel.
+
+	  This option allows the kernel to invoke the secure monitor 
whenever
+	  required on devices using Trusted Foundations.
+
+	  Devices using Trusted Foundations should pass a device tree
containing +	  a node compatible with "tl,trusted-foundations" to
signal the presence +	  of the secure monitor.
What about pointing to the documentation file instead?
quoted hunk ↗ jump to hunk
+
+endmenu
diff --git a/arch/arm/firmware/Makefile b/arch/arm/firmware/Makefile
new file mode 100644
index 0000000..a71f165
--- /dev/null
+++ b/arch/arm/firmware/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_TRUSTED_FOUNDATIONS)	+= trusted_foundations.o
diff --git a/arch/arm/firmware/trusted_foundations.c
b/arch/arm/firmware/trusted_foundations.c new file mode 100644
index 0000000..181f348
--- /dev/null
+++ b/arch/arm/firmware/trusted_foundations.c
@@ -0,0 +1,83 @@
+/*
+ * Trusted Foundations support for ARM CPUs
+ *
+ * Copyright (c) 2013, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
by + * the Free Software Foundation; either version 2 of the License,
or + * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
WITHOUT + * ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for + * more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <asm/firmware.h>
+#include <asm/trusted_foundations.h>
+
+#define TF_SET_CPU_BOOT_ADDR_SMC 0xfffff200
+
+static void __naked tf_generic_smc(u32 type, u32 subtype, u32 arg)
+{
+	asm volatile(
+		".arch_extension	sec\n\t"
+		"stmfd	sp!, {r4 - r11, lr}\n\t"
+		__asmeq("%0", "r0")
+		__asmeq("%1", "r1")
+		__asmeq("%2", "r2")
+		"mov	r3, #0\n\t"
+		"mov	r4, #0\n\t"
+		"smc	#0\n\t"
+		"ldmfd	sp!, {r4 - r11, pc}"
+		:
+		: "r" (type), "r" (subtype), "r" (arg)
+		: "memory");
+}
+
+static int tf_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
+{
+	tf_generic_smc(TF_SET_CPU_BOOT_ADDR_SMC, boot_addr, 0);
+
+	return 0;
+}
+
+static const struct firmware_ops trusted_foundations_ops = {
+	.set_cpu_boot_addr = tf_set_cpu_boot_addr,
+};
+
+void register_trusted_foundations(struct
trusted_foundations_platform_data *pd) +{
+	/* we are not using version information for now since currently
+	 * supported SMCs are compatible with all TF releases */
+	register_firmware_ops(&trusted_foundations_ops);
+}
+
+void of_register_trusted_foundations(void)
+{
+	struct device_node *node;
+
+	node = of_find_compatible_node(NULL, NULL, "tl,trusted-
foundations");

nit:
	if (!node)
		return;

+	if (node) {
+		struct trusted_foundations_platform_data pdata;
+		int err;
+
+		err = of_property_read_u32(node, "version-major",
+					   &pdata.version_major);
+		if (err != 0) {
+			pr_crit("Trusted Foundation: missing version-
major\n");
+			BUG();
+		}
+		err = of_property_read_u32(node, "version-minor",
+					   &pdata.version_minor);
+		if (err != 0) {
+			pr_crit("Trusted Foundation: missing version-
minor\n");
+			BUG();
+		}
If version was stored in multiple cells of a single property, then it 
would be parsed by just one call to of_property_read_u32_array().
quoted hunk ↗ jump to hunk
+		register_trusted_foundations(&pdata);
+	}
+}
diff --git a/arch/arm/include/asm/trusted_foundations.h
b/arch/arm/include/asm/trusted_foundations.h new file mode 100644
index 0000000..77a4961
--- /dev/null
+++ b/arch/arm/include/asm/trusted_foundations.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2013, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
by + * the Free Software Foundation; either version 2 of the License,
or + * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
WITHOUT + * ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for + * more details.
+ */
+
+#ifndef __ASM_ARM_TRUSTED_FOUNDATIONS_H
+#define __ASM_ARM_TRUSTED_FOUNDATIONS_H
+
+#include <linux/kconfig.h>
+#include <linux/printk.h>
+#include <asm/bug.h>
+
+struct trusted_foundations_platform_data {
+	unsigned int version_major;
+	unsigned int version_minor;
+};
+
+#if IS_ENABLED(CONFIG_TRUSTED_FOUNDATIONS)
+
+void register_trusted_foundations(struct
trusted_foundations_platform_data *pd); +void
of_register_trusted_foundations(void);
+
+#else
+
+static inline void register_trusted_foundations(
+				   struct 
trusted_foundations_platform_data *pd)
+{
+	pr_crit("No support for Trusted Foundations, stopping...\n");
+	BUG();
Hmm, why not simply panic()?

Best regards,
Tomasz
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