Fixes ordering of header files inclusion in PSCI firmware driver.

Signed-off-by: Etienne Carriere etienne.carriere@linaro.org --- drivers/firmware/psci.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c index 657e7eb5ae..f845ba67f8 100644 --- a/drivers/firmware/psci.c +++ b/drivers/firmware/psci.c @@ -9,18 +9,18 @@ #include <common.h> #include <command.h> #include <dm.h> +#include <efi_loader.h> #include <irq_func.h> #include <log.h> -#include <dm/lists.h> -#include <efi_loader.h> #include <sysreset.h> -#include <linux/delay.h> -#include <linux/libfdt.h> +#include <asm/system.h> +#include <dm/lists.h> #include <linux/arm-smccc.h> +#include <linux/delay.h> #include <linux/errno.h> +#include <linux/libfdt.h> #include <linux/printk.h> #include <linux/psci.h> -#include <asm/system.h>

#define DRIVER_NAME "psci"

Use PSCI device to query Arm SMCCC v1.1 support from secure monitor and if so, bind drivers for the SMCCC features that monitor supports.

Drivers willing to be bound from Arm SMCCC features discovery can use macro ARM_SMCCC_FEATURE_DRIVER() to register to smccc feature discovery, providing target driver name and a callback function that returns whether or not the SMCCC feature is supported by the system.

Signed-off-by: Etienne Carriere etienne.carriere@linaro.org --- drivers/firmware/Kconfig | 8 ++++ drivers/firmware/psci.c | 81 ++++++++++++++++++++++++++++++++++++++- include/linux/arm-smccc.h | 16 ++++++++ include/linux/psci.h | 14 +++++++ 4 files changed, 118 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index ef958b3a7a..f10d1aaf4b 100644 --- a/drivers/firmware/Kconfig +++ b/drivers/firmware/Kconfig @@ -37,4 +37,12 @@ config ZYNQMP_FIRMWARE Say yes to enable ZynqMP firmware interface driver. If in doubt, say N.

+config ARM_SMCCC_FEATURES + bool "Arm SMCCC features discovery" + depends on ARM_PSCI_FW + help + Discover Arm SMCCC features for which a U-Boot driver is defined. When enabled, + the PSCI driver is always probed and binds dirvers registered to the Arm SMCCC + services if any and reported as supported by the SMCCC firmware. + source "drivers/firmware/scmi/Kconfig" diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c index f845ba67f8..ef3e983646 100644 --- a/drivers/firmware/psci.c +++ b/drivers/firmware/psci.c @@ -11,9 +11,11 @@ #include <dm.h> #include <efi_loader.h> #include <irq_func.h> +#include <linker_lists.h> #include <log.h> #include <sysreset.h> #include <asm/system.h> +#include <dm/device-internal.h> #include <dm/lists.h> #include <linux/arm-smccc.h> #include <linux/delay.h> @@ -95,6 +97,76 @@ static bool psci_is_system_reset2_supported(void) return false; }

+static void smccc_invoke_hvc(unsigned long a0, unsigned long a1, + unsigned long a2, unsigned long a3, + unsigned long a4, unsigned long a5, + unsigned long a6, unsigned long a7, + struct arm_smccc_res *res) +{ + arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res); +} + +static void smccc_invoke_smc(unsigned long a0, unsigned long a1, + unsigned long a2, unsigned long a3, + unsigned long a4, unsigned long a5, + unsigned long a6, unsigned long a7, + struct arm_smccc_res *res) +{ + arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res); +} + +static int bind_smccc_features(struct udevice *dev, int psci_method) +{ + struct psci_plat_data *pdata = dev_get_plat(dev); + struct arm_smccc_feature *feature; + size_t feature_cnt, n; + + if (!IS_ENABLED(CONFIG_ARM_SMCCC_FEATURES)) + return 0; + + /* + * SMCCC features discovery invoke SMCCC standard function ID + * ARM_SMCCC_ARCH_FEATURES but this sequence requires that this + * standard ARM_SMCCC_ARCH_FEATURES function ID itself is supported. + * It is queried here with invoking PSCI_FEATURES known available + * from PSCI 1.0. + */ + if (!device_is_compatible(dev, "arm,psci-1.0") || + PSCI_VERSION_MAJOR(psci_0_2_get_version()) == 0) + return 0; + + if (request_psci_features(ARM_SMCCC_ARCH_FEATURES) == + PSCI_RET_NOT_SUPPORTED) + return 0; + + if (psci_method == PSCI_METHOD_HVC) + pdata->invoke_fn = smccc_invoke_hvc; + else + pdata->invoke_fn = smccc_invoke_smc; + + feature_cnt = ll_entry_count(struct arm_smccc_feature, arm_smccc_feature); + feature = ll_entry_start(struct arm_smccc_feature, arm_smccc_feature); + + for (n = 0; n < feature_cnt; n++, feature++) { + const char *drv_name = feature->driver_name; + struct udevice *dev2; + int ret; + + if (!feature->is_supported || !feature->is_supported(pdata->invoke_fn)) + continue; + + ret = device_bind_driver(dev, drv_name, drv_name, &dev2); + if (ret) { + pr_warn("%s was not bound: %d, ignore\n", drv_name, ret); + continue; + } + + dev_set_parent_plat(dev2, dev_get_plat(dev)); + } + + return 0; +} + static int psci_bind(struct udevice *dev) { /* No SYSTEM_RESET support for PSCI 0.1 */ @@ -109,6 +181,10 @@ static int psci_bind(struct udevice *dev) pr_debug("PSCI System Reset was not bound.\n"); }

+ /* From PSCI v1.0 onward we can discover services through ARM_SMCCC_FEATURE */ + if (IS_ENABLED(CONFIG_ARM_SMCCC_FEATURES) && device_is_compatible(dev, "arm,psci-1.0")) + dev_or_flags(dev, DM_FLAG_PROBE_AFTER_BIND); + return 0; }

@@ -136,7 +212,7 @@ static int psci_probe(struct udevice *dev) return -EINVAL; }

- return 0; + return bind_smccc_features(dev, psci_method); }

/** @@ -240,4 +316,7 @@ U_BOOT_DRIVER(psci) = { .of_match = psci_of_match, .bind = psci_bind, .probe = psci_probe, +#ifdef CONFIG_ARM_SMCCC_FEATURES + .plat_auto = sizeof(struct psci_plat_data), +#endif }; diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index 94a20c9793..e1d09884a1 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -83,6 +83,22 @@ struct arm_smccc_quirk { } state; };

+/** + * struct arm_smccc_feature - Driver registration data for discoverable feature + * @driver_name: name of the driver relate to the SMCCC feature + * @is_supported: callback to test if SMCCC feature is supported + */ +struct arm_smccc_feature { + const char *driver_name; + bool (*is_supported)(void (*invoke_fn)(unsigned long a0, unsigned long a1, unsigned long a2, + unsigned long a3, unsigned long a4, unsigned long a5, + unsigned long a6, unsigned long a7, + struct arm_smccc_res *res)); +}; + +#define ARM_SMCCC_FEATURE_DRIVER(__name) \ + ll_entry_declare(struct arm_smccc_feature, __name, arm_smccc_feature) + /** * __arm_smccc_smc() - make SMC calls * @a0-a7: arguments passed in registers 0 to 7 diff --git a/include/linux/psci.h b/include/linux/psci.h index c78c1079a8..03e4186343 100644 --- a/include/linux/psci.h +++ b/include/linux/psci.h @@ -11,6 +11,8 @@ #ifndef _UAPI_LINUX_PSCI_H #define _UAPI_LINUX_PSCI_H

+#include <linux/arm-smccc.h> + /* * PSCI v0.1 interface * @@ -115,6 +117,18 @@ #define PSCI_RET_DISABLED -8 #define PSCI_RET_INVALID_ADDRESS -9

+/** + * struct psci_plat_data - PSCI driver platform data + * @method: Selected invocation conduit + */ +struct psci_plat_data { + void (*invoke_fn)(unsigned long arg0, unsigned long arg1, + unsigned long arg2, unsigned long arg3, + unsigned long arg4, unsigned long arg5, + unsigned long arg6, unsigned long arg7, + struct arm_smccc_res *res); +}; + #ifdef CONFIG_ARM_PSCI_FW unsigned long invoke_psci_fn(unsigned long a0, unsigned long a1, unsigned long a2, unsigned long a3);

Adds random number generator driver using Arm SMCCC TRNG interface to get entropy bytes from secure monitor. The driver registers as an Arm SMCCC feature driver to allow PSCI driver to bind a device for when secure monitor exposes RNG support from Arm SMCCC TRNG interface.

Cc: Sughosh Ganu sughosh.ganu@linaro.org Cc: Heinrich Schuchardt xypron.glpk@gmx.de Signed-off-by: Etienne Carriere etienne.carriere@linaro.org --- MAINTAINERS | 5 + drivers/rng/Kconfig | 9 ++ drivers/rng/Makefile | 1 + drivers/rng/smccc_trng.c | 207 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 222 insertions(+) create mode 100644 drivers/rng/smccc_trng.c

diff --git a/MAINTAINERS b/MAINTAINERS index 56be0bfad0..5a92b8bfcb 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1231,6 +1231,11 @@ F: drivers/gpio/sl28cpld-gpio.c F: drivers/misc/sl28cpld.c F: drivers/watchdog/sl28cpld-wdt.c

+SMCCC TRNG +M: Etienne Carriere etienne.carriere@linaro.org +S: Maintained +F: drivers/rng/smccc_trng.c + SPI M: Jagan Teki jagan@amarulasolutions.com S: Maintained diff --git a/drivers/rng/Kconfig b/drivers/rng/Kconfig index c10f7d345b..6f73be8f9b 100644 --- a/drivers/rng/Kconfig +++ b/drivers/rng/Kconfig @@ -58,4 +58,13 @@ config RNG_IPROC200 depends on DM_RNG help Enable random number generator for RPI4. + +config RNG_SMCCC_TRNG + bool "Arm SMCCC TRNG interface" + depends on DM_RNG && ARM_PSCI_FW + default y if ARM_SMCCC_FEATURES + help + Enable random number generator for platforms that support Arm + SMCCC TRNG interface. + endif diff --git a/drivers/rng/Makefile b/drivers/rng/Makefile index 435b3b965a..20c40a964c 100644 --- a/drivers/rng/Makefile +++ b/drivers/rng/Makefile @@ -11,3 +11,4 @@ obj-$(CONFIG_RNG_OPTEE) += optee_rng.o obj-$(CONFIG_RNG_STM32MP1) += stm32mp1_rng.o obj-$(CONFIG_RNG_ROCKCHIP) += rockchip_rng.o obj-$(CONFIG_RNG_IPROC200) += iproc_rng200.o +obj-$(CONFIG_RNG_SMCCC_TRNG) += smccc_trng.o diff --git a/drivers/rng/smccc_trng.c b/drivers/rng/smccc_trng.c new file mode 100644 index 0000000000..3a4bb33941 --- /dev/null +++ b/drivers/rng/smccc_trng.c @@ -0,0 +1,207 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2022, Linaro Limited + */ + +#define LOG_CATEGORY UCLASS_RNG + +#include <common.h> +#include <dm.h> +#include <linker_lists.h> +#include <log.h> +#include <rng.h> +#include <dm/device_compat.h> +#include <linux/arm-smccc.h> +#include <linux/bitops.h> +#include <linux/kernel.h> +#include <linux/psci.h> + +#define DRIVER_NAME "smccc-trng" + +/** + * Arm SMCCC TRNG firmware interface specification: + * https://developer.arm.com/documentation/den0098/latest/ + */ +#define ARM_SMCCC_TRNG_VERSION 0x84000050 +#define ARM_SMCCC_TRNG_FEATURES 0x84000051 +#define ARM_SMCCC_TRNG_GET_UUID 0x84000052 +#define ARM_SMCCC_TRNG_RND_32 0x84000053 +#define ARM_SMCCC_TRNG_RND_64 0xC4000053 + +#define ARM_SMCCC_RET_TRNG_SUCCESS ((ulong)0) +#define ARM_SMCCC_RET_TRNG_NOT_SUPPORTED ((ulong)-1) +#define ARM_SMCCC_RET_TRNG_INVALID_PARAMETER ((ulong)-2) +#define ARM_SMCCC_RET_TRNG_NO_ENTROPY ((ulong)-3) + +#define TRNG_MAJOR_MASK GENMASK(30, 16) +#define TRNG_MAJOR_SHIFT 16 +#define TRNG_MINOR_MASK GENMASK(15, 0) +#define TRNG_MINOR_SHIFT 0 + +#define TRNG_MAX_RND_64 (192 / 8) +#define TRNG_MAX_RND_32 (96 / 8) + +/** + * struct smccc_trng_priv - Private data for SMCCC TRNG support + * + * @smc64 - True if TRNG_RND_64 is supported, false if TRNG_RND_32 is supported + */ +struct smccc_trng_priv { + bool smc64; +}; + +/* + * Copy random bytes from ulong SMCCC output register to target buffer + * Defines 2 function flavors for whether ARM_SMCCC_TRNG_RND_32 or + * ARM_SMCCC_TRNG_RND_64 was used to invoke the service. + */ +static size_t smc32_copy_sample(u8 **ptr, size_t size, ulong *rnd) +{ + size_t len = min(size, sizeof(u32)); + u32 sample = *rnd; + + memcpy(*ptr, &sample, len); + *ptr += len; + + return size - len; +} + +static size_t smc64_copy_sample(u8 **ptr, size_t size, ulong *rnd) +{ + size_t len = min(size, sizeof(u64)); + u64 sample = *rnd; + + memcpy(*ptr, &sample, len); + *ptr += len; + + return size - len; +} + +static int smccc_trng_read(struct udevice *dev, void *data, size_t len) +{ + struct psci_plat_data *smccc = dev_get_parent_plat(dev); + struct smccc_trng_priv *priv = dev_get_priv(dev); + struct arm_smccc_res res; + u32 func_id; + u8 *ptr = data; + size_t rem = len; + size_t max_sz; + size_t (*copy_sample)(u8 **ptr, size_t size, ulong *rnd); + + if (priv->smc64) { + copy_sample = smc64_copy_sample; + func_id = ARM_SMCCC_TRNG_RND_64; + max_sz = TRNG_MAX_RND_64; + } else { + copy_sample = smc32_copy_sample; + func_id = ARM_SMCCC_TRNG_RND_32; + max_sz = TRNG_MAX_RND_32; + } + + while (rem) { + size_t sz = min(rem, max_sz); + + smccc->invoke_fn(func_id, sz * 8, 0, 0, 0, 0, 0, 0, &res); + + switch (res.a0) { + case ARM_SMCCC_RET_TRNG_SUCCESS: + break; + case ARM_SMCCC_RET_TRNG_NO_ENTROPY: + continue; + default: + return -EIO; + } + + rem -= sz; + + sz = copy_sample(&ptr, sz, &res.a3); + if (sz) + sz = copy_sample(&ptr, sz, &res.a2); + if (sz) + sz = copy_sample(&ptr, sz, &res.a1); + } + + return 0; +} + +static const struct dm_rng_ops smccc_trng_ops = { + .read = smccc_trng_read, +}; + +static bool smccc_trng_is_supported(void (*invoke_fn)(unsigned long a0, unsigned long a1, + unsigned long a2, unsigned long a3, + unsigned long a4, unsigned long a5, + unsigned long a6, unsigned long a7, + struct arm_smccc_res *res)) +{ + struct arm_smccc_res res; + + (*invoke_fn)(ARM_SMCCC_ARCH_FEATURES, ARM_SMCCC_TRNG_VERSION, 0, 0, 0, 0, 0, 0, &res); + if (res.a0 == ARM_SMCCC_RET_NOT_SUPPORTED) + return false; + + (*invoke_fn)(ARM_SMCCC_TRNG_VERSION, 0, 0, 0, 0, 0, 0, 0, &res); + if (res.a0 & BIT(31)) + return false; + + /* Test 64bit interface and fallback to 32bit interface */ + invoke_fn(ARM_SMCCC_TRNG_FEATURES, ARM_SMCCC_TRNG_RND_64, + 0, 0, 0, 0, 0, 0, &res); + + if (res.a0 == ARM_SMCCC_RET_TRNG_NOT_SUPPORTED) + invoke_fn(ARM_SMCCC_TRNG_FEATURES, ARM_SMCCC_TRNG_RND_32, + 0, 0, 0, 0, 0, 0, &res); + + return res.a0 == ARM_SMCCC_RET_TRNG_SUCCESS; +} + +ARM_SMCCC_FEATURE_DRIVER(smccc_trng) = { + .driver_name = DRIVER_NAME, + .is_supported = smccc_trng_is_supported, +}; + +static int smccc_trng_probe(struct udevice *dev) +{ + struct psci_plat_data *smccc = dev_get_parent_plat(dev); + struct smccc_trng_priv *priv = dev_get_priv(dev); + struct arm_smccc_res res; + + if (!(smccc_trng_is_supported(smccc->invoke_fn))) + return -ENODEV; + + /* At least one of 64bit and 32bit interfaces is available */ + smccc->invoke_fn(ARM_SMCCC_TRNG_FEATURES, ARM_SMCCC_TRNG_RND_64, + 0, 0, 0, 0, 0, 0, &res); + priv->smc64 = (res.a0 == ARM_SMCCC_RET_TRNG_SUCCESS); + +#ifdef DEBUG + smccc->invoke_fn(ARM_SMCCC_TRNG_GET_UUID, 0, 0, 0, 0, 0, 0, 0, &res); + if (res.a0 != ARM_SMCCC_RET_TRNG_NOT_SUPPORTED) { + unsigned long uuid_a0 = res.a0; + unsigned long uuid_a1 = res.a1; + unsigned long uuid_a2 = res.a2; + unsigned long uuid_a3 = res.a3; + unsigned long major, minor; + + smccc->invoke_fn(ARM_SMCCC_TRNG_VERSION, 0, 0, 0, 0, 0, 0, 0, &res); + major = (res.a0 & TRNG_MAJOR_MASK) >> TRNG_MAJOR_SHIFT; + minor = (res.a0 & TRNG_MINOR_MASK) >> TRNG_MINOR_SHIFT; + + dev_dbg(dev, "Version %lu.%lu, UUID %08lx-%04lx-%04lx-%04lx-%04lx%08lx\n", + major, minor, uuid_a0, uuid_a1 >> 16, uuid_a1 & GENMASK(16, 0), + uuid_a2 >> 16, uuid_a2 & GENMASK(16, 0), uuid_a3); + } else { + dev_warn(dev, "Can't get TRNG UUID\n"); + } +#endif + + return 0; +} + +U_BOOT_DRIVER(smccc_trng) = { + .name = DRIVER_NAME, + .id = UCLASS_RNG, + .ops = &smccc_trng_ops, + .probe = smccc_trng_probe, + .priv_auto = sizeof(struct smccc_trng_priv), +};