[U-Boot] [PATCH 2/2] sysreset: psci: support system reset in a generic way with PSCI

Masahiro Yamada
2017-04-10T08:41:19Z

If the system is running PSCI firmware, the System Reset function
(func ID: 0x80000009) is supposed to be handled by PSCI, that is,
the SoC/board specific reset implementation should be moved to PSCI.
U-Boot should call the PSCI service according to the arm-smccc
manner. The arm-smccc is supported on ARMv7 or later. Especially,
ARMv8 generation SoCs are likely to run ARM Trusted Firmware. In
this case, U-Boot is a non-secure world boot loader, so it should
not be able to reset the system directly.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

arch/arm/Kconfig | 1 +
drivers/Kconfig | 2 +
drivers/Makefile | 5 +-
drivers/firmware/Kconfig | 6 +++
drivers/firmware/Makefile | 2 +
drivers/firmware/firmware-uclass.c | 11 +++++
drivers/firmware/psci.c | 94 ++++++++++++++++++++++++++++++++++++++
drivers/sysreset/Kconfig | 11 +++++
drivers/sysreset/Makefile | 1 +
drivers/sysreset/sysreset_psci.c | 41 +++++++++++++++++
include/dm/uclass-id.h | 1 +
include/linux/psci.h | 13 ++++++
12 files changed, 186 insertions(+), 2 deletions(-)
create mode 100644 drivers/firmware/Kconfig
create mode 100644 drivers/firmware/Makefile
create mode 100644 drivers/firmware/firmware-uclass.c
create mode 100644 drivers/firmware/psci.c
create mode 100644 drivers/sysreset/sysreset_psci.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 84744ef..64984dc 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -177,6 +177,7 @@ config SYS_CACHELINE_SIZE
config ARM_SMCCC
bool "Support for ARM SMC Calling Convention (SMCCC)"
depends on CPU_V7 || ARM64
+ select ARM_PSCI_FW
help
Say Y here if you want to enable ARM SMC Calling Convention.
This should be enabled if U-Boot needs to communicate with system
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 0e5d97d..d0a36ab 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -22,6 +22,8 @@ source "drivers/dfu/Kconfig"

source "drivers/dma/Kconfig"

+source "drivers/firmware/Kconfig"
+
source "drivers/fpga/Kconfig"

source "drivers/gpio/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index 5d8baa5..4a4b237 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -23,7 +23,7 @@ obj-$(CONFIG_SPL_SERIAL_SUPPORT) += serial/
obj-$(CONFIG_SPL_SPI_SUPPORT) += spi/
obj-$(CONFIG_SPL_POWER_SUPPORT) += power/ power/pmic/
obj-$(CONFIG_SPL_POWER_SUPPORT) += power/regulator/
-obj-$(CONFIG_SPL_DRIVERS_MISC_SUPPORT) += misc/ sysreset/
+obj-$(CONFIG_SPL_DRIVERS_MISC_SUPPORT) += misc/ sysreset/ firmware/
obj-$(CONFIG_SPL_MTD_SUPPORT) += mtd/
obj-$(CONFIG_SPL_NAND_SUPPORT) += mtd/nand/
obj-$(CONFIG_SPL_ONENAND_SUPPORT) += mtd/onenand/
@@ -52,7 +52,7 @@ endif
ifdef CONFIG_TPL_BUILD

obj-$(CONFIG_TPL_I2C_SUPPORT) += i2c/
-obj-$(CONFIG_TPL_DRIVERS_MISC_SUPPORT) += misc/ sysreset/
+obj-$(CONFIG_TPL_DRIVERS_MISC_SUPPORT) += misc/ sysreset/ firmware/
obj-$(CONFIG_TPL_MMC_SUPPORT) += mmc/
obj-$(CONFIG_TPL_MPC8XXX_INIT_DDR_SUPPORT) += ddr/fsl/
obj-$(CONFIG_TPL_NAND_SUPPORT) += mtd/nand/
@@ -71,6 +71,7 @@ obj-y += block/
obj-$(CONFIG_BOOTCOUNT_LIMIT) += bootcount/
obj-$(CONFIG_CPU) += cpu/
obj-y += crypto/
+obj-y += firmware/
obj-$(CONFIG_FPGA) += fpga/
obj-y += hwmon/
obj-y += misc/
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
new file mode 100644
index 0000000..4c32426
--- /dev/null
+++ b/drivers/firmware/Kconfig
@@ -0,0 +1,6 @@
+config FIRMWARE
+ bool
+
+config ARM_PSCI_FW
+ bool
+ select FIRMWARE
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
new file mode 100644
index 0000000..b208255
--- /dev/null
+++ b/drivers/firmware/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_FIRMWARE) += firmware-uclass.o
+obj-$(CONFIG_ARM_PSCI_FW) += psci.o
diff --git a/drivers/firmware/firmware-uclass.c b/drivers/firmware/firmware-uclass.c
new file mode 100644
index 0000000..01b6a44
--- /dev/null
+++ b/drivers/firmware/firmware-uclass.c
@@ -0,0 +1,11 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <dm/uclass.h>
+
+/* Firmware access is platform-dependent. No generic code in uclass */
+UCLASS_DRIVER(firmware) = {
+ .id = UCLASS_FIRMWARE,
+ .name = "firmware",
+};
diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
new file mode 100644
index 0000000..40fba64
--- /dev/null
+++ b/drivers/firmware/psci.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2017 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * Based on drivers/firmware/psci.c from Linux:
+ * Copyright (C) 2015 ARM Limited
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm/device.h>
+#include <dm/lists.h>
+#include <libfdt.h>
+#include <linux/arm-smccc.h>
+#include <linux/errno.h>
+#include <linux/psci.h>
+
+psci_fn *invoke_psci_fn;
+
+static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
+ unsigned long arg0, unsigned long arg1,
+ unsigned long arg2)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
+ return res.a0;
+}
+
+static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
+ unsigned long arg0, unsigned long arg1,
+ unsigned long arg2)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
+ return res.a0;
+}
+
+static int psci_bind(struct udevice *dev)
+{
+ /* No SYSTEM_RESET support for PSCI 0.1 */
+ if (of_device_is_compatible(dev, "arm,psci-0.2") ||
+ of_device_is_compatible(dev, "arm,psci-1.0")) {
+ int ret;
+
+ /* bind psci-sysreset optionally */
+ ret = device_bind_driver(dev, "psci-sysreset", "psci-sysreset",
+ NULL);
+ if (ret)
+ debug("PSCI System Reset was not bound.\n");
+ }
+
+ return 0;
+}
+
+static int psci_probe(struct udevice *dev)
+{
+ DECLARE_GLOBAL_DATA_PTR;
+ const char *method;
+
+ method = fdt_stringlist_get(gd->fdt_blob, dev->of_offset, "method", 0,
+ NULL);
+ if (!method) {
+ printf("missing \"method\" property\n");
+ return -ENXIO;
+ }
+
+ if (!strcmp("hvc", method)) {
+ invoke_psci_fn = __invoke_psci_fn_hvc;
+ } else if (!strcmp("smc", method)) {
+ invoke_psci_fn = __invoke_psci_fn_smc;
+ } else {
+ printf("invalid \"method\" property: %s\n", method);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static const struct udevice_id psci_of_match[] = {
+ { .compatible = "arm,psci" },
+ { .compatible = "arm,psci-0.2" },
+ { .compatible = "arm,psci-1.0" },
+ {},
+};
+
+U_BOOT_DRIVER(psci) = {
+ .name = "psci",
+ .id = UCLASS_FIRMWARE,
+ .of_match = psci_of_match,
+ .bind = psci_bind,
+ .probe = psci_probe,
+};
diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
index 05a37b9..1498d37 100644
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -13,4 +13,15 @@ config SYSRESET
to effect a reset. The uclass will try all available drivers when
reset_walk() is called.

+if SYSRESET
+
+config SYSRESET_PSCI
+ bool "Enable support for PSCI System Reset"
+ depends on ARM_PSCI_FW
+ help
+ Enable PSCI SYSTEM_RESET function call. To use this, PSCI service
+ (for example, ARM Trusted Firmware BL31) must be running on your
+ system.
+
+endif
endmenu
diff --git a/drivers/sysreset/Makefile b/drivers/sysreset/Makefile
index 49b8bb6..7bb8406 100644
--- a/drivers/sysreset/Makefile
+++ b/drivers/sysreset/Makefile
@@ -5,6 +5,7 @@
#

obj-$(CONFIG_SYSRESET) += sysreset-uclass.o
+obj-$(CONFIG_SYSRESET_PSCI) += sysreset_psci.o

ifndef CONFIG_SPL_BUILD
obj-$(CONFIG_ROCKCHIP_RK3036) += sysreset_rk3036.o
diff --git a/drivers/sysreset/sysreset_psci.c b/drivers/sysreset/sysreset_psci.c
new file mode 100644
index 0000000..a4911b7
--- /dev/null
+++ b/drivers/sysreset/sysreset_psci.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2017 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <dm/device.h>
+#include <sysreset.h>
+#include <linux/errno.h>
+#include <linux/psci.h>
+
+static int psci_sysreset_request(struct udevice *dev, enum sysreset_t type)
+{
+ unsigned long function_id;
+
+ switch (type) {
+ case SYSRESET_WARM:
+ case SYSRESET_COLD:
+ function_id = PSCI_0_2_FN_SYSTEM_RESET;
+ break;
+ case SYSRESET_POWER:
+ function_id = PSCI_0_2_FN_SYSTEM_OFF;
+ break;
+ default:
+ return -ENOSYS;
+ }
+
+ invoke_psci_fn(function_id, 0, 0, 0);
+
+ return -EINPROGRESS;
+}
+
+static struct sysreset_ops psci_sysreset_ops = {
+ .request = psci_sysreset_request,
+};
+
+U_BOOT_DRIVER(psci_sysreset) = {
+ .name = "psci-sysreset",
+ .id = UCLASS_SYSRESET,
+ .ops = &psci_sysreset_ops,
+};
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 8c92d0b..1b635e4 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -35,6 +35,7 @@ enum uclass_id {
UCLASS_DMA, /* Direct Memory Access */
UCLASS_ETH, /* Ethernet device */
UCLASS_GPIO, /* Bank of general-purpose I/O pins */
+ UCLASS_FIRMWARE, /* Firmware */
UCLASS_I2C, /* I2C bus */
UCLASS_I2C_EEPROM, /* I2C EEPROM device */
UCLASS_I2C_GENERIC, /* Generic I2C device */
diff --git a/include/linux/psci.h b/include/linux/psci.h
index 310d83e..8d13bd2 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -87,4 +87,17 @@
#define PSCI_RET_NOT_PRESENT -7
#define PSCI_RET_DISABLED -8

+#ifdef CONFIG_ARM_PSCI_FW
+typedef unsigned long (psci_fn)(unsigned long, unsigned long,
+ unsigned long, unsigned long);
+
+extern psci_fn *invoke_psci_fn;
+#else
+unsigned long invoke_psci_fn(unsigned long a0, unsigned long a1,
+ unsigned long a2, unsigned long a3)
+{
+ return PSCI_RET_DISABLED;
+}
+#endif
+
#endif /* _UAPI_LINUX_PSCI_H */
--
2.7.4