| Message ID | 1376360992-1508-2-git-send-email-acourbot@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 08/12/2013 08:29 PM, Alexandre Courbot wrote: > 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. > diff --git a/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt > +Trusted Foundations > + > +Boards that use the Trusted Foundations secure monitor can signal its > +presence by declaring a node compatible with "tl,trusted-foundations" > +(the name and location of the node does not matter). > + > +Required properties: > +- compatible : "tl,trusted-foundations" > +- version : Must contain the version number string of the Trusted Foundation > + firmware. Can the version be queried at run-time from the firmware itself? If not, I wonder if we shouldn't instead encode the version number into the compatible value. Some comments on the exact format of the version property would be useful; from the example I assume it's "%02d.%02d" % (major_ver, minor_ver)? > diff --git a/arch/arm/firmware/Kconfig b/arch/arm/firmware/Kconfig > +config ARCH_SUPPORTS_TRUSTED_FOUNDATIONS > + bool Shouldn't that be "config ARCH_SUPPORTS_FIRMWARE", since presumably in the future there will be more entries in the menu, and hence we want the menu to appear if any of those entries are useful? > + > +menu "Firmware options" > + depends on ARCH_SUPPORTS_TRUSTED_FOUNDATIONS Or perhaps that comment is more appropriate for that "depends".
On Tue, Aug 13, 2013 at 11:29:48AM +0900, Alexandre Courbot wrote: > 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 | 16 ++++++ > .../devicetree/bindings/vendor-prefixes.txt | 1 + > arch/arm/Kconfig | 2 + > arch/arm/Makefile | 1 + > arch/arm/firmware/Kconfig | 22 ++++++++ > arch/arm/firmware/Makefile | 1 + > arch/arm/firmware/trusted_foundations.c | 58 ++++++++++++++++++++++ > arch/arm/include/asm/trusted_foundations.h | 36 ++++++++++++++ > 8 files changed, 137 insertions(+) > create mode 100644 Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt > 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..2609f78 > --- /dev/null > +++ b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt > @@ -0,0 +1,16 @@ > +Trusted Foundations > + > +Boards that use the Trusted Foundations secure monitor can signal its > +presence by declaring a node compatible with "tl,trusted-foundations" > +(the name and location of the node does not matter). We shouldn't encougrage people to arrange DT nodes at random. Unless there's a good reason not to, this should just be a child of /, with the meaning that the firmware is callable (at least to the point of discoverability) on all CPUs. The meaning of the node should be left unspecified if it is in any other location. This is the convention already adopted for things like arm,psci (though to be fair, the arm,psci binding documentation fails to mention that also -- nonetheless, the node is placed in /). > + > +Required properties: > +- compatible : "tl,trusted-foundations" > +- version : Must contain the version number string of the Trusted Foundation > + firmware. Are you sure there is no low-level way to probe vendor and version info? If there is, then the DT should describe nothing except the fact that the probe interface exists. I also worry that two integrations on different SoCs might have the same version number, yet still be different due to vendor-specific features and options. > + > +Example: > + firmware { > + compatible = "tl,trusted-foundations"; > + version = "02.08"; > + }; > 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/ > 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..ad0eb6c > --- /dev/null > +++ b/arch/arm/firmware/Kconfig > @@ -0,0 +1,22 @@ > +config ARCH_SUPPORTS_TRUSTED_FOUNDATIONS > + bool > + > +menu "Firmware options" > + depends on ARCH_SUPPORTS_TRUSTED_FOUNDATIONS > + > +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. > + > +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..051482d > --- /dev/null > +++ b/arch/arm/firmware/trusted_foundations.c > @@ -0,0 +1,58 @@ > +/* > + * 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> > + > +#define TF_SET_CPU_BOOT_ADDR_SMC 0xfffff200 > + Better to use __naked instead of an explicit attribute. > +static void __attribute__((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(const char *version) > +{ > + /* we are not using version information for now since currently > + * supported SMCs are compatible with all TF releases */ I think it would be wise at least to sanity-check the version, even if there's only one major version supported for now. > + register_firmware_ops(&trusted_foundations_ops); > +} > diff --git a/arch/arm/include/asm/trusted_foundations.h b/arch/arm/include/asm/trusted_foundations.h > new file mode 100644 > index 0000000..d187905 > --- /dev/null > +++ b/arch/arm/include/asm/trusted_foundations.h > @@ -0,0 +1,36 @@ > +/* > + * 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> > + > +#if IS_ENABLED(CONFIG_TRUSTED_FOUNDATIONS) > + > +void register_trusted_foundations(const char *version); > + > +#else > + > +static inline void register_trusted_foundations(const char *version) > +{ > + pr_crit("No support for Trusted Foundations, stopping...\n"); > + BUG(); > +} > + > +#endif /* IS_ENABLED(CONFIG_TRUSTED_FOUNDATIONS) */ > + > +#endif > -- > 1.8.3.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On 08/15/2013 05:52 AM, Dave Martin wrote: > On Tue, Aug 13, 2013 at 11:29:48AM +0900, Alexandre Courbot wrote: >> 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. >> diff --git a/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt >> +Required properties: >> +- compatible : "tl,trusted-foundations" >> +- version : Must contain the version number string of the Trusted Foundation >> + firmware. > > Are you sure there is no low-level way to probe vendor and version info? > If there is, then the DT should describe nothing except the fact that > the probe interface exists. > > I also worry that two integrations on different SoCs might have the > same version number, yet still be different due to vendor-specific > features and options. I would expect HW-specific compatible values also to be present in a DT. For example, perhaps: compatible = "tl,trusted-foundations-nvidia-shield", "tl,trusted-foundations"; (nvidia vendor, shield board/implementation) This would allow matching on the specific value "tl,trusted-foundations-nvidia-shield" in the future if some quirking was needed, but if this wasn't needed, drivers could just bind to the generic "tl,trusted-foundations". >> +- version : Must contain the version number string of the Trusted Foundation >> + firmware. > > Are you sure there is no low-level way to probe vendor and version info? > If there is, then the DT should describe nothing except the fact that > the probe interface exists. > > I also worry that two integrations on different SoCs might have the > same version number, yet still be different due to vendor-specific > features and options. Talking of the version - if we do need to represent this in the DT, how about 2 separate cells for major/minor version rather than encoding it into a string? Then, no parsing would be required.
On Thu, Aug 15, 2013 at 04:02:52PM -0600, Stephen Warren wrote: > On 08/15/2013 05:52 AM, Dave Martin wrote: > > On Tue, Aug 13, 2013 at 11:29:48AM +0900, Alexandre Courbot wrote: > >> 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. > > >> diff --git a/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt > > >> +Required properties: > >> +- compatible : "tl,trusted-foundations" > >> +- version : Must contain the version number string of the Trusted Foundation > >> + firmware. > > > > Are you sure there is no low-level way to probe vendor and version info? > > If there is, then the DT should describe nothing except the fact that > > the probe interface exists. > > > > I also worry that two integrations on different SoCs might have the > > same version number, yet still be different due to vendor-specific > > features and options. > > I would expect HW-specific compatible values also to be present in a DT. > For example, perhaps: > > compatible = "tl,trusted-foundations-nvidia-shield", > "tl,trusted-foundations"; > > (nvidia vendor, shield board/implementation) > > This would allow matching on the specific value > "tl,trusted-foundations-nvidia-shield" in the future if some quirking > was needed, but if this wasn't needed, drivers could just bind to the > generic "tl,trusted-foundations". That seems reasonable *unless* there is a reliable way to obtain a vendor ID from the SMC ABI directly, in which case we should just use that. One could debate whether the extra compatible string should have "nvidia," or "tl," but the fact that "nvidia" is in the name at all pretty much narrows it down. > > >> +- version : Must contain the version number string of the Trusted Foundation > >> + firmware. > > > > Are you sure there is no low-level way to probe vendor and version info? > > If there is, then the DT should describe nothing except the fact that > > the probe interface exists. > > > > I also worry that two integrations on different SoCs might have the > > same version number, yet still be different due to vendor-specific > > features and options. > > Talking of the version - if we do need to represent this in the DT, how > about 2 separate cells for major/minor version rather than encoding it > into a string? Then, no parsing would be required. I think the key thing here is to match whatever TF's native notion of version is. If it's truly a string with specific comparison rules, we should leave it a string and write code to examine it. If it's a simple <major minor> pair, then putting it in the DT in this form makes sense. And, as you previosly suggested, if there's a reliable ABI for getting the firmware to tell you its version number, we should just use that and not describe the version number in the DT at all. I'm not in a position to answer that one. If we really have no idea, we'll have to go with a best guess, and change the compatible string later if necessary. But it would be better to get it right if we can. If TF has version/vendor probe interfaces but those might be missing/ broken/wrong, we could still specify "vendor" and "version" properties which allow the probed values to be overridden. Cheers ---Dave
On Thu, Aug 15, 2013 at 6:35 AM, Stephen Warren <swarren@wwwdotorg.org> wrote: > On 08/12/2013 08:29 PM, Alexandre Courbot wrote: >> 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. > >> diff --git a/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt > >> +Trusted Foundations >> + >> +Boards that use the Trusted Foundations secure monitor can signal its >> +presence by declaring a node compatible with "tl,trusted-foundations" >> +(the name and location of the node does not matter). >> + >> +Required properties: >> +- compatible : "tl,trusted-foundations" > >> +- version : Must contain the version number string of the Trusted Foundation >> + firmware. > > Can the version be queried at run-time from the firmware itself? I'm afraid there is not, unfortunately. :/ > If not, I wonder if we shouldn't instead encode the version number into > the compatible value. Why? This would make the node harder to find and would also complicate the case where a given firmware handler can support a given range of versions (which is what I expect will happen). > Some comments on the exact format of the version property would be > useful; from the example I assume it's "%02d.%02d" % (major_ver, minor_ver)? Agreed. >> diff --git a/arch/arm/firmware/Kconfig b/arch/arm/firmware/Kconfig > >> +config ARCH_SUPPORTS_TRUSTED_FOUNDATIONS >> + bool > > Shouldn't that be "config ARCH_SUPPORTS_FIRMWARE", since presumably in > the future there will be more entries in the menu, and hence we want the > menu to appear if any of those entries are useful? The things is that because you support one firmware does not mean you will support then all. Only some set of architectures will support firmware X, and another set (maybe not inclusive) will support firmware Y. We do not want to allow selecting firmware Y if the kernel does not support any of the architectures that may make use of it. >> + >> +menu "Firmware options" >> + depends on ARCH_SUPPORTS_TRUSTED_FOUNDATIONS > > Or perhaps that comment is more appropriate for that "depends". Here the idea is to not show the "Firmware options" menu if the kernel does not include support for any architecture that uses them. As more firmwares get added, the depends line should expand into something like "depends on ARCH_SUPPORTS_FIRMWARE_X || ARCH_SUPPORTS_FIRMWARE_Y || ... Maybe there's a better way to express this? Thanks, Alex.
On Thu, Aug 15, 2013 at 8:52 PM, Dave Martin <Dave.Martin@arm.com> wrote: > On Tue, Aug 13, 2013 at 11:29:48AM +0900, Alexandre Courbot wrote: >> 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 | 16 ++++++ >> .../devicetree/bindings/vendor-prefixes.txt | 1 + >> arch/arm/Kconfig | 2 + >> arch/arm/Makefile | 1 + >> arch/arm/firmware/Kconfig | 22 ++++++++ >> arch/arm/firmware/Makefile | 1 + >> arch/arm/firmware/trusted_foundations.c | 58 ++++++++++++++++++++++ >> arch/arm/include/asm/trusted_foundations.h | 36 ++++++++++++++ >> 8 files changed, 137 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt >> 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..2609f78 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt >> @@ -0,0 +1,16 @@ >> +Trusted Foundations >> + >> +Boards that use the Trusted Foundations secure monitor can signal its >> +presence by declaring a node compatible with "tl,trusted-foundations" >> +(the name and location of the node does not matter). > > We shouldn't encougrage people to arrange DT nodes at random. > > Unless there's a good reason not to, this should just be a child > of /, with the meaning that the firmware is callable (at least to > the point of discoverability) on all CPUs. > > The meaning of the node should be left unspecified if it is in any > other location. > > This is the convention already adopted for things like arm,psci (though > to be fair, the arm,psci binding documentation fails to mention that > also -- nonetheless, the node is placed in /). I agree the node should be a child of /. At the moment this is not enforced at runtime though (because of the use of of_find_compatible_node()), is it ok if this is just specified as a rule in the bindings? >> + >> +Required properties: >> +- compatible : "tl,trusted-foundations" >> +- version : Must contain the version number string of the Trusted Foundation >> + firmware. > > Are you sure there is no low-level way to probe vendor and version info? > If there is, then the DT should describe nothing except the fact that > the probe interface exists. I have looked for such a probing method myself and asked some people who know better than me, and the answer was that there was none, unfortunately. :( > I also worry that two integrations on different SoCs might have the > same version number, yet still be different due to vendor-specific > features and options. I also investigated that point (since it was raised for v2 as well) and the answer was that for TF as least, the interface should not be different across vendors. > >> + >> +Example: >> + firmware { >> + compatible = "tl,trusted-foundations"; >> + version = "02.08"; >> + }; >> 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/ >> 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..ad0eb6c >> --- /dev/null >> +++ b/arch/arm/firmware/Kconfig >> @@ -0,0 +1,22 @@ >> +config ARCH_SUPPORTS_TRUSTED_FOUNDATIONS >> + bool >> + >> +menu "Firmware options" >> + depends on ARCH_SUPPORTS_TRUSTED_FOUNDATIONS >> + >> +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. >> + >> +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..051482d >> --- /dev/null >> +++ b/arch/arm/firmware/trusted_foundations.c >> @@ -0,0 +1,58 @@ >> +/* >> + * 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> >> + >> +#define TF_SET_CPU_BOOT_ADDR_SMC 0xfffff200 >> + > > Better to use __naked instead of an explicit attribute. Will fix, thanks. > >> +static void __attribute__((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(const char *version) >> +{ >> + /* we are not using version information for now since currently >> + * supported SMCs are compatible with all TF releases */ > > I think it would be wise at least to sanity-check the version, > even if there's only one major version supported for now. Ok. Thanks, Alex.
On Fri, Aug 16, 2013 at 10:23 PM, Dave Martin <Dave.Martin@arm.com> wrote: > On Thu, Aug 15, 2013 at 04:02:52PM -0600, Stephen Warren wrote: >> On 08/15/2013 05:52 AM, Dave Martin wrote: >> > On Tue, Aug 13, 2013 at 11:29:48AM +0900, Alexandre Courbot wrote: >> >> 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. >> >> >> diff --git a/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt >> >> >> +Required properties: >> >> +- compatible : "tl,trusted-foundations" >> >> +- version : Must contain the version number string of the Trusted Foundation >> >> + firmware. >> > >> > Are you sure there is no low-level way to probe vendor and version info? >> > If there is, then the DT should describe nothing except the fact that >> > the probe interface exists. >> > >> > I also worry that two integrations on different SoCs might have the >> > same version number, yet still be different due to vendor-specific >> > features and options. >> >> I would expect HW-specific compatible values also to be present in a DT. >> For example, perhaps: >> >> compatible = "tl,trusted-foundations-nvidia-shield", >> "tl,trusted-foundations"; >> >> (nvidia vendor, shield board/implementation) >> >> This would allow matching on the specific value >> "tl,trusted-foundations-nvidia-shield" in the future if some quirking >> was needed, but if this wasn't needed, drivers could just bind to the >> generic "tl,trusted-foundations". > > That seems reasonable *unless* there is a reliable way to obtain > a vendor ID from the SMC ABI directly, in which case we should just > use that. > > One could debate whether the extra compatible string should have > "nvidia," or "tl," but the fact that "nvidia" is in the name at all > pretty much narrows it down. > >> >> >> +- version : Must contain the version number string of the Trusted Foundation >> >> + firmware. >> > >> > Are you sure there is no low-level way to probe vendor and version info? >> > If there is, then the DT should describe nothing except the fact that >> > the probe interface exists. >> > >> > I also worry that two integrations on different SoCs might have the >> > same version number, yet still be different due to vendor-specific >> > features and options. >> >> Talking of the version - if we do need to represent this in the DT, how >> about 2 separate cells for major/minor version rather than encoding it >> into a string? Then, no parsing would be required. > > I think the key thing here is to match whatever TF's native notion of > version is. > > If it's truly a string with specific comparison rules, we should leave it > a string and write code to examine it. If it's a simple <major minor> > pair, then putting it in the DT in this form makes sense. TF's native version is this major/minor pair, and indeed it should be sensible and harmless to turn it into a pair of cells. Then there are other components that can be added to build a more precise "version string". You can have a look at this file to see how this is done: http://nv-tegra.nvidia.com/gitweb/?p=linux-2.6.git;a=blob;f=security/tf_driver/s_version.h;h=d75c5f35d32d597b664c9533b1c5a52696e81b49;hb=rel-roth-ota-1 The version string I used to far is the S_VERSION_MAIN macro, since it is the only one that seems to be platform-independant. S_VERSION_PLATFORM and S_VERSION_OS can be used to indentify if Android is used and which version. Then all these strings (plus a few others) are concatenated to build S_VERSION_STRING which is the ultimate version, but also considerably more complicated to handle. At the current level of support, I don't think it makes sense to look further than S_VERSION_MAIN for the moment. If we switch it to a pair of integer cells as Stephen suggested, nothing prevents us to extend the bindings with other properties (for instance version-platform and version-os) if they become necessary. But at the moment I don't think it makes sense to overthink versions beyond the main version number, especially if it can be extended safely if needed in the future. Thanks, Alex.
On 08/18/2013 02:37 AM, Alexandre Courbot wrote: > On Thu, Aug 15, 2013 at 6:35 AM, Stephen Warren <swarren@wwwdotorg.org> wrote: >> On 08/12/2013 08:29 PM, Alexandre Courbot wrote: >>> 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. >> >>> diff --git a/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt >> >>> +Trusted Foundations >>> + >>> +Boards that use the Trusted Foundations secure monitor can signal its >>> +presence by declaring a node compatible with "tl,trusted-foundations" >>> +(the name and location of the node does not matter). >>> + >>> +Required properties: >>> +- compatible : "tl,trusted-foundations" >> >>> +- version : Must contain the version number string of the Trusted Foundation >>> + firmware. >> >> Can the version be queried at run-time from the firmware itself? > > I'm afraid there is not, unfortunately. :/ > >> If not, I wonder if we shouldn't instead encode the version number into >> the compatible value. > > Why? This would make the node harder to find and would also complicate > the case where a given firmware handler can support a given range of > versions (which is what I expect will happen). I guess that would be painful. There are probably a lot more valid version numbers for a SW firmware interface than there are for a HW IP block interface, so it makes less sense to encoded the version into the compatible value, at least in cases where the interface is "similar enough"; we can add some kind of basic version number into the compatible values for radically different interfaces if they appear in the future. >>> diff --git a/arch/arm/firmware/Kconfig b/arch/arm/firmware/Kconfig >> >>> +config ARCH_SUPPORTS_TRUSTED_FOUNDATIONS >>> + bool >> >> Shouldn't that be "config ARCH_SUPPORTS_FIRMWARE", since presumably in >> the future there will be more entries in the menu, and hence we want the >> menu to appear if any of those entries are useful? > > The things is that because you support one firmware does not mean you > will support then all. Only some set of architectures will support > firmware X, and another set (maybe not inclusive) will support > firmware Y. We do not want to allow selecting firmware Y if the kernel > does not support any of the architectures that may make use of it. > >>> + >>> +menu "Firmware options" >>> + depends on ARCH_SUPPORTS_TRUSTED_FOUNDATIONS >> >> Or perhaps that comment is more appropriate for that "depends". > > Here the idea is to not show the "Firmware options" menu if the kernel > does not include support for any architecture that uses them. As more > firmwares get added, the depends line should expand into something > like "depends on ARCH_SUPPORTS_FIRMWARE_X || ARCH_SUPPORTS_FIRMWARE_Y > || ... > > Maybe there's a better way to express this? Is there a need for a menu at all? I suppose it might group things nicely. If so, how about: config ARCH_SUPPORTS_FIRMWARE bool config ARCH_SUPPORTS_TRUSTED_FOUNDATIONS bool select ARCH_SUPPORTS_FIRMWARE config ARCH_SUPPORTS_SOME_OTHER_FW bool select ARCH_SUPPORTS_FIRMWARE menu "Firmware options" depends on ARCH_SUPPORTS_FIRMWARE That's probably slightly easier to read than a huge "depends" statement in the menu stanza, and ARCH_SUPPORTS_FIRMWARE might be a useful to build in support for any core firmware utility code.
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..2609f78 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt @@ -0,0 +1,16 @@ +Trusted Foundations + +Boards that use the Trusted Foundations secure monitor can signal its +presence by declaring a node compatible with "tl,trusted-foundations" +(the name and location of the node does not matter). + +Required properties: +- compatible : "tl,trusted-foundations" +- version : Must contain the version number string of the Trusted Foundation + firmware. + +Example: + firmware { + compatible = "tl,trusted-foundations"; + version = "02.08"; + }; 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/ 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..ad0eb6c --- /dev/null +++ b/arch/arm/firmware/Kconfig @@ -0,0 +1,22 @@ +config ARCH_SUPPORTS_TRUSTED_FOUNDATIONS + bool + +menu "Firmware options" + depends on ARCH_SUPPORTS_TRUSTED_FOUNDATIONS + +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. + +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..051482d --- /dev/null +++ b/arch/arm/firmware/trusted_foundations.c @@ -0,0 +1,58 @@ +/* + * 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> + +#define TF_SET_CPU_BOOT_ADDR_SMC 0xfffff200 + +static void __attribute__((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(const char *version) +{ + /* we are not using version information for now since currently + * supported SMCs are compatible with all TF releases */ + register_firmware_ops(&trusted_foundations_ops); +} diff --git a/arch/arm/include/asm/trusted_foundations.h b/arch/arm/include/asm/trusted_foundations.h new file mode 100644 index 0000000..d187905 --- /dev/null +++ b/arch/arm/include/asm/trusted_foundations.h @@ -0,0 +1,36 @@ +/* + * 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> + +#if IS_ENABLED(CONFIG_TRUSTED_FOUNDATIONS) + +void register_trusted_foundations(const char *version); + +#else + +static inline void register_trusted_foundations(const char *version) +{ + pr_crit("No support for Trusted Foundations, stopping...\n"); + BUG(); +} + +#endif /* IS_ENABLED(CONFIG_TRUSTED_FOUNDATIONS) */ + +#endif
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 | 16 ++++++ .../devicetree/bindings/vendor-prefixes.txt | 1 + arch/arm/Kconfig | 2 + arch/arm/Makefile | 1 + arch/arm/firmware/Kconfig | 22 ++++++++ arch/arm/firmware/Makefile | 1 + arch/arm/firmware/trusted_foundations.c | 58 ++++++++++++++++++++++ arch/arm/include/asm/trusted_foundations.h | 36 ++++++++++++++ 8 files changed, 137 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/firmware/tl,trusted-foundations.txt 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