On 3/5/21 12:50 AM, Sean Anderson wrote:
On 3/4/21 12:00 PM, Heinrich Schuchardt wrote:
Provide sysreset driver using the SBI system reset extension.
Signed-off-by: Heinrich Schuchardt <xypron.g...@gmx.de>
---
MAINTAINERS | 1 +
arch/riscv/include/asm/sbi.h | 1 +
arch/riscv/lib/sbi.c | 21 +++++--
drivers/sysreset/Kconfig | 11 ++++
drivers/sysreset/Makefile | 1 +
drivers/sysreset/sysreset_sbi.c | 102 ++++++++++++++++++++++++++++++++
lib/efi_loader/Kconfig | 2 +-
7 files changed, 134 insertions(+), 5 deletions(-)
create mode 100644 drivers/sysreset/sysreset_sbi.c
diff --git a/MAINTAINERS b/MAINTAINERS
index de499940e5..192db06ff9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -985,6 +985,7 @@ T: git
https://source.denx.de/u-boot/custodians/u-boot-riscv.git
F: arch/riscv/
F: cmd/riscv/
F: doc/usage/sbi.rst
+F: drivers/sysreset/sysreset_sbi.c
F: drivers/timer/andes_plmt_timer.c
F: drivers/timer/sifive_clint_timer.c
F: tools/prelink-riscv.c
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index c598bb11ce..058e2e23a8 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -150,5 +150,6 @@ void sbi_set_timer(uint64_t stime_value);
long sbi_get_spec_version(void);
int sbi_get_impl_id(void);
int sbi_probe_extension(int ext);
+void sbi_srst_reset(unsigned long type, unsigned long reason);
#endif
diff --git a/arch/riscv/lib/sbi.c b/arch/riscv/lib/sbi.c
index 77845a73ca..8508041f2a 100644
--- a/arch/riscv/lib/sbi.c
+++ b/arch/riscv/lib/sbi.c
@@ -8,13 +8,14 @@
*/
#include <common.h>
+#include <efi_loader.h>
#include <asm/encoding.h>
#include <asm/sbi.h>
-struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
- unsigned long arg1, unsigned long arg2,
- unsigned long arg3, unsigned long arg4,
- unsigned long arg5)
+struct sbiret __efi_runtime sbi_ecall(int ext, int fid, unsigned long
arg0,
+ unsigned long arg1, unsigned long arg2,
+ unsigned long arg3, unsigned long arg4,
+ unsigned long arg5)
{
struct sbiret ret;
@@ -108,6 +109,18 @@ int sbi_probe_extension(int extid)
return -ENOTSUPP;
}
+/**
+ * sbi_srst_reset() - invoke system reset extension
+ *
+ * @type: type of reset
+ * @reason: reason for reset
+ */
+void __efi_runtime sbi_srst_reset(unsigned long type, unsigned long
reason)
+{
+ sbi_ecall(SBI_EXT_SRST, SBI_EXT_SRST_RESET, type, reason,
+ 0, 0, 0, 0);
+}
+
#ifdef CONFIG_SBI_V01
/**
diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
index 0e5c7c9971..05a7e26300 100644
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -79,6 +79,17 @@ config SYSRESET_PSCI
Enable PSCI SYSTEM_RESET function call. To use this, PSCI
firmware
must be running on your system.
+config SYSRESET_SBI
+ bool "Enable support for SBI System Reset"
+ depends on RISCV_SMODE && SBI_V02
+ select SYSRESET_CMD_POWEROFF if CMD_POWEROFF
+ help
+ Enable system reset and poweroff via the SBI system reset
extension.
+ If the SBI implemention provides the extension, is board specific.
+ The extension was introduced in version 0.3 of the SBI
specification.
+ The SBI system reset driver supports the UEFI ResetSystem()
service
+ at runtime.
+
config SYSRESET_SOCFPGA
bool "Enable support for Intel SOCFPGA family"
depends on ARCH_SOCFPGA && (TARGET_SOCFPGA_GEN5 ||
TARGET_SOCFPGA_ARRIA10)
diff --git a/drivers/sysreset/Makefile b/drivers/sysreset/Makefile
index de81c399d7..8e00be0779 100644
--- a/drivers/sysreset/Makefile
+++ b/drivers/sysreset/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_SYSRESET_MPC83XX) += sysreset_mpc83xx.o
obj-$(CONFIG_SYSRESET_MICROBLAZE) += sysreset_microblaze.o
obj-$(CONFIG_SYSRESET_OCTEON) += sysreset_octeon.o
obj-$(CONFIG_SYSRESET_PSCI) += sysreset_psci.o
+obj-$(CONFIG_SYSRESET_SBI) += sysreset_sbi.o
obj-$(CONFIG_SYSRESET_SOCFPGA) += sysreset_socfpga.o
obj-$(CONFIG_SYSRESET_SOCFPGA_SOC64) += sysreset_socfpga_soc64.o
obj-$(CONFIG_SYSRESET_TI_SCI) += sysreset-ti-sci.o
diff --git a/drivers/sysreset/sysreset_sbi.c
b/drivers/sysreset/sysreset_sbi.c
new file mode 100644
index 0000000000..87fbc3ea3e
--- /dev/null
+++ b/drivers/sysreset/sysreset_sbi.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2021, Heinrich Schuchardt <xypron.g...@gmx.de>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <efi_loader.h>
+#include <log.h>
+#include <sysreset.h>
+#include <asm/sbi.h>
+
+static long __efi_runtime_data have_reset;
+
+static int sbi_sysreset_request(struct udevice *dev, enum sysreset_t
type)
+{
+ enum sbi_srst_reset_type reset_type;
+
+ if (!have_reset)
+ return -ENOENT;
Is this necessary? This should never be called if there is no reset,
since we just fail to probe.
Thank you for reviewing.
Yes, we can skip it.
+
+ switch (type) {
+ case SYSRESET_WARM:
+ reset_type = SBI_SRST_RESET_TYPE_WARM_REBOOT;
+ break;
+ case SYSRESET_COLD:
+ reset_type = SBI_SRST_RESET_TYPE_COLD_REBOOT;
+ break;
+ case SYSRESET_POWER_OFF:
+ reset_type = SBI_SRST_RESET_TYPE_SHUTDOWN;
+ break;
+ default:
+ log_err("SBI has no system reset extension\n");
+ return -ENOSYS;
+ }
+
+ sbi_srst_reset(reset_type, SBI_SRST_RESET_REASON_NONE);
+
+ return -EINPROGRESS;
+}
+
+efi_status_t efi_reset_system_init(void)
+{
+ return EFI_SUCCESS;
+}
+
+void __efi_runtime EFIAPI efi_reset_system(enum efi_reset_type type,
+ efi_status_t reset_status,
+ unsigned long data_size,
+ void *reset_data)
As an aside, is there a reason why the generic (weak) efi_reset_system
does not just call sysreset_walk_halt(type)?
efi_reset_system is invoked at UEFI runtime. Most functions of U-Boot
are no longer in memory after ExitBootServices(). Only functions in the
__efi_runtime section may be called.
+{
+ enum sbi_srst_reset_type reset_type;
+
+ if (have_reset)
+ switch (type) {
+ case SYSRESET_WARM:
+ reset_type = SBI_SRST_RESET_TYPE_WARM_REBOOT;
+ break;
+ case SYSRESET_COLD:
+ reset_type = SBI_SRST_RESET_TYPE_COLD_REBOOT;
+ break;
+ case SYSRESET_POWER_OFF:
+ reset_type = SBI_SRST_RESET_TYPE_SHUTDOWN;
+ break;
+ default:
+ goto hang;
Why do we hang by default? For comparison, sysreset_x86 has
if (reset_type == EFI_RESET_COLD ||
reset_type == EFI_RESET_PLATFORM_SPECIFIC)
value = SYS_RST | RST_CPU | FULL_RST;
else /* assume EFI_RESET_WARM since we cannot return an error */
value = SYS_RST | RST_CPU;
ok
+ }
+
+ sbi_srst_reset(reset_type, SBI_SRST_RESET_REASON_NONE);
Should we instead do
enum sbi_srst_reset_reason reset_reason;
if (reset_status == EFI_SUCCESS)
reset_reason = SBI_SRST_RESET_REASON_NONE;
else
reset_reason = SBI_SRST_RESET_REASON_SYS_FAILURE;
sbi_srst_reset(reset_type, reset_status == EFI_SUCCESS ?
SBI_SRST_RESET_REASON_NONE : SBI_SRST_RESET_REASON_SYS_FAILURE);
since we have reset status available?
Makes sense.
+
+hang:
+ while (1)
+ ;
+}
+
+static int sbi_sysreset_probe(struct udevice *dev)
+{
+ have_reset = sbi_probe_extension(SBI_EXT_SRST);
+ if (have_reset)
+ return 0;
+
+ log_err("SBI has no system reset extension\n");
Is this an error? It's perfectly normal for SBI implementations to lack
support for some extensions. Perhaps a warning/info would be better.
We shouldn't have chosen this driver in the configuration if the SBI
does not support it.
I will change this to a warning.
+ return -ENOENT;
+}
+
+static const struct udevice_id sbi_sysreset_ids[] = {
+ { .compatible = "riscv" },
This compatible string is already in-use for RISC-V CPUs. And if this
isn't supposed to have a device tree binding, do we even need of_match?
I discussed this with Simon in
https://lists.denx.de/pipermail/u-boot/2021-March/443270.html
Instead of adding code to the board files we should have a device-tree
node. A reasonable compatible string would be "riscv,sbi-sysreset".
+ { }
+};
+
+static struct sysreset_ops sbi_sysreset_ops = {
+ .request = sbi_sysreset_request,
+};
+
+U_BOOT_DRIVER(sbi_sysreset) = {
+ .name = "sbi-sysreset",
+ .id = UCLASS_SYSRESET,
+ .of_match = sbi_sysreset_ids,
+ .ops = &sbi_sysreset_ops,
+ .probe = sbi_sysreset_probe,
+};
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index e729f727df..7e76435339 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -277,7 +277,7 @@ config EFI_HAVE_RUNTIME_RESET
bool
default y
depends on ARCH_BCM283X || FSL_LAYERSCAPE || PSCI_RESET || \
- SANDBOX || SYSRESET_X86
+ SANDBOX || SYSRESET_SBI || SYSRESET_X86
As a general note, perhaps it is better to set this from other Kconfigs?
How long will this list get?
This seems to be a matter of taste.
Best regards
Heinrich
--Sean
config EFI_GRUB_ARM32_WORKAROUND
bool "Workaround for GRUB on 32bit ARM"
--
2.30.1
