Add a generic driver that binds to armv8 CPU nodes. The generic driver allows - to enumerate CPUs present in a system, even when no other driver binds it - generates ACPI SSDT code for each CPU - Fill the ACPI MADT table (implemented in a follow up patch)
The newly introduced code could also be reused on other CPU drivers that are compatible with armv8.
TEST: Booted on QEMU sbsa and verify the driver binds to CPU nodes. Confirmed with FWTS that all ACPI processor devices are present.
Signed-off-by: Patrick Rudolph patrick.rudolph@9elements.com Reviewed-by: Simon Glass sjg@chromium.org Cc: Tom Rini trini@konsulko.com Cc: Simon Glass sjg@chromium.org --- Changelog v4: - Export armv8_cpu_fill_ssdt to use it in other CPU drivers
--- drivers/cpu/Kconfig | 6 ++++ drivers/cpu/Makefile | 2 ++ drivers/cpu/armv8_cpu.c | 73 +++++++++++++++++++++++++++++++++++++++++ drivers/cpu/armv8_cpu.h | 21 ++++++++++++ 4 files changed, 102 insertions(+) create mode 100644 drivers/cpu/armv8_cpu.c create mode 100644 drivers/cpu/armv8_cpu.h
diff --git a/drivers/cpu/Kconfig b/drivers/cpu/Kconfig index 5c06cd9f60..9c0df331d7 100644 --- a/drivers/cpu/Kconfig +++ b/drivers/cpu/Kconfig @@ -26,6 +26,12 @@ config CPU_RISCV help Support CPU cores for RISC-V architecture.
+config CPU_ARMV8 + bool "Enable generic ARMv8 CPU driver" + depends on CPU && ARM64 + help + Support CPU cores for armv8 architecture. + config CPU_MICROBLAZE bool "Enable Microblaze CPU driver" depends on CPU && MICROBLAZE diff --git a/drivers/cpu/Makefile b/drivers/cpu/Makefile index bc75d9b974..773395693a 100644 --- a/drivers/cpu/Makefile +++ b/drivers/cpu/Makefile @@ -6,10 +6,12 @@
obj-$(CONFIG_CPU) += cpu-uclass.o
+ obj-$(CONFIG_ARCH_BMIPS) += bmips_cpu.o obj-$(CONFIG_ARCH_IMX8) += imx8_cpu.o obj-$(CONFIG_ARCH_AT91) += at91_cpu.o obj-$(CONFIG_ARCH_MEDIATEK) += mtk_cpu.o +obj-$(CONFIG_CPU_ARMV8) += armv8_cpu.o obj-$(CONFIG_CPU_IMX) += imx8_cpu.o obj-$(CONFIG_CPU_MPC83XX) += mpc83xx_cpu.o obj-$(CONFIG_CPU_RISCV) += riscv_cpu.o diff --git a/drivers/cpu/armv8_cpu.c b/drivers/cpu/armv8_cpu.c new file mode 100644 index 0000000000..1572e087e0 --- /dev/null +++ b/drivers/cpu/armv8_cpu.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2024 9elements GmbH + */ +#include <acpi/acpigen.h> +#include <asm/armv8/cpu.h> +#include <cpu.h> +#include <dm.h> +#include <dm/acpi.h> +#include <asm/io.h> +#include <linux/bitops.h> +#include <linux/printk.h> +#include <linux/sizes.h> + +static int armv8_cpu_get_desc(const struct udevice *dev, char *buf, int size) +{ + int cpuid; + + cpuid = (read_midr() & MIDR_PARTNUM_MASK) >> MIDR_PARTNUM_SHIFT; + + snprintf(buf, size, "CPU MIDR %04x", cpuid); + + return 0; +} + +static int armv8_cpu_get_info(const struct udevice *dev, + struct cpu_info *info) +{ + info->cpu_freq = 0; + info->features = BIT(CPU_FEAT_L1_CACHE) | BIT(CPU_FEAT_MMU); + + return 0; +} + +static int armv8_cpu_get_count(const struct udevice *dev) +{ + return uclass_id_count(UCLASS_CPU); +} + +#ifdef CONFIG_ACPIGEN +int armv8_cpu_fill_ssdt(const struct udevice *dev, struct acpi_ctx *ctx) +{ + uint core_id = dev_seq(dev); + + acpigen_write_processor_device(ctx, core_id); + + return 0; +} + +struct acpi_ops armv8_cpu_acpi_ops = { + .fill_ssdt = armv8_cpu_fill_ssdt, +}; +#endif + +static const struct cpu_ops cpu_ops = { + .get_count = armv8_cpu_get_count, + .get_desc = armv8_cpu_get_desc, + .get_info = armv8_cpu_get_info, +}; + +static const struct udevice_id cpu_ids[] = { + { .compatible = "arm,armv8" }, + {} +}; + +U_BOOT_DRIVER(arm_cpu) = { + .name = "arm-cpu", + .id = UCLASS_CPU, + .of_match = cpu_ids, + .ops = &cpu_ops, + .flags = DM_FLAG_PRE_RELOC, + ACPI_OPS_PTR(&armv8_cpu_acpi_ops) +}; diff --git a/drivers/cpu/armv8_cpu.h b/drivers/cpu/armv8_cpu.h new file mode 100644 index 0000000000..2c4b0252cf --- /dev/null +++ b/drivers/cpu/armv8_cpu.h @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2024 9elements GmbH + */ +#include <dm/acpi.h> +#include <dm/device.h> + +#ifndef _ARMV8_CPU_H_ +#define _ARMV8_CPU_H_ + +/** + * armv8_cpu_fill_ssdt() - Fill the SSDT + * Parses the FDT and writes the SSDT nodes. + * + * @dev: cpu device to generate ACPI tables for + * @ctx: ACPI context pointer + * @return: 0 if OK, or a negative error code. + */ +int armv8_cpu_fill_ssdt(const struct udevice *dev, struct acpi_ctx *ctx); + +#endif \ No newline at end of file