When ACPI is enabled over FDT the APs cannot be brought out of reset by the OS using the "FDT spin-table" mechanism, as no FDT is provided to the OS. The APs must be released out of reset in u-boot and then brought up in an ACPI compliant fashion.
When ARMV8_MULTIENTRY is specified, the APs are released from reset and will enter U-Boot after it has been relocated as well.
By default ARMV8_MULTIENTRY is not selected, keeping existing behaviour.
TEST: All APs enter U-Boot when run on qemu-system-aarch64 and on real hardware.
Signed-off-by: Patrick Rudolph patrick.rudolph@9elements.com Reviewed-by: Simon Glass sjg@chromium.org Cc: Matthias Brugger mbrugger@suse.com Cc: Peter Robinson pbrobinson@gmail.com Cc: Tom Rini trini@konsulko.com --- Changelog v2: - Drop CPU code from board - Add CPU driver to release APs from reset Changelog v4: - Use the generic armv8 CPU driver - Probe all CPUs - Release secondary CPUs in the probe function - Use of_to_plat() to parse DT - Drop udelay() - Select the GICv2 driver Changelog v5: - Cosmetic fixes - Drop arch_early_init_r() Changelog v6: - Update header order - Drop ifdef --- arch/arm/Kconfig | 1 + arch/arm/mach-bcm283x/Kconfig | 5 +- drivers/cpu/Makefile | 2 +- drivers/cpu/bcm283x_cpu.c | 214 ++++++++++++++++++++++++++++++++++ 4 files changed, 220 insertions(+), 2 deletions(-) create mode 100644 drivers/cpu/bcm283x_cpu.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 0d0c731dd0..787f983ffd 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -651,6 +651,7 @@ config ARCH_ORION5X
config ARCH_BCM283X bool "Broadcom BCM283X family" + select CPU select DM select DM_GPIO select DM_SERIAL diff --git a/arch/arm/mach-bcm283x/Kconfig b/arch/arm/mach-bcm283x/Kconfig index b3287ce8bc..0ef8156c64 100644 --- a/arch/arm/mach-bcm283x/Kconfig +++ b/arch/arm/mach-bcm283x/Kconfig @@ -24,7 +24,9 @@ config BCM2837_64B bool "Broadcom BCM2837 SoC 64-bit support" depends on ARCH_BCM283X select BCM2837 + select DRIVER_GICV2 select ARM64 + select CPU_ARMV8
config BCM2711 bool "Broadcom BCM2711 SoC support" @@ -42,11 +44,12 @@ config BCM2711_64B bool "Broadcom BCM2711 SoC 64-bit support" depends on ARCH_BCM283X select BCM2711 + select DRIVER_GICV2 select ARM64 + select CPU_ARMV8
menu "Broadcom BCM283X family" depends on ARCH_BCM283X - choice prompt "Broadcom BCM283X board select" optional diff --git a/drivers/cpu/Makefile b/drivers/cpu/Makefile index 773395693a..eaf494706e 100644 --- a/drivers/cpu/Makefile +++ b/drivers/cpu/Makefile @@ -6,7 +6,7 @@
obj-$(CONFIG_CPU) += cpu-uclass.o
- +obj-$(CONFIG_ARCH_BCM283X) += bcm283x_cpu.o obj-$(CONFIG_ARCH_BMIPS) += bmips_cpu.o obj-$(CONFIG_ARCH_IMX8) += imx8_cpu.o obj-$(CONFIG_ARCH_AT91) += at91_cpu.o diff --git a/drivers/cpu/bcm283x_cpu.c b/drivers/cpu/bcm283x_cpu.c new file mode 100644 index 0000000000..59a7b142c9 --- /dev/null +++ b/drivers/cpu/bcm283x_cpu.c @@ -0,0 +1,214 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2024 9elements GmbH + */ + +#include <cpu.h> +#include <cpu_func.h> +#include <dm.h> +#include <fdt_support.h> +#include <acpi/acpigen.h> +#include <asm/armv8/cpu.h> +#include <asm/cache.h> +#include <asm/io.h> +#include <asm/global_data.h> +#include <asm/system.h> +#include <asm-generic/sections.h> +#include <linux/bitops.h> +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include "armv8_cpu.h" + +DECLARE_GLOBAL_DATA_PTR; + +struct bcm_plat { + u64 release_addr; +}; + +static int cpu_bcm_get_desc(const struct udevice *dev, char *buf, int size) +{ + struct cpu_plat *plat = dev_get_parent_plat(dev); + const char *name; + + if (size < 32) + return -ENOSPC; + + if (device_is_compatible(dev, "arm,cortex-a53")) + name = "A53"; + else if (device_is_compatible(dev, "arm,cortex-a72")) + name = "A72"; + else + name = "?"; + + snprintf(buf, size, "Broadcom Cortex-%s at %u MHz\n", + name, plat->timebase_freq); + + return 0; +} + +static int cpu_bcm_get_info(const struct udevice *dev, struct cpu_info *info) +{ + struct cpu_plat *plat = dev_get_parent_plat(dev); + + info->cpu_freq = plat->timebase_freq * 1000; + info->features = BIT(CPU_FEAT_L1_CACHE) | BIT(CPU_FEAT_MMU); + + return 0; +} + +static int cpu_bcm_get_count(const struct udevice *dev) +{ + return uclass_id_count(UCLASS_CPU); +} + +static int cpu_bcm_get_vendor(const struct udevice *dev, char *buf, int size) +{ + snprintf(buf, size, "Broadcom"); + + return 0; +} + +static int cpu_bcm_is_current(struct udevice *dev) +{ + struct cpu_plat *plat = dev_get_parent_plat(dev); + + if (plat->cpu_id == (read_mpidr() & 0xffff)) + return 1; + + return 0; +} + +/** + * bcm_cpu_on - Releases the secondary CPU from it's spintable + * + * Write the CPU's spintable mailbox and let the CPU enter U-Boot. + * + * @dev: Device to start + * @return: zero on success or error code on failure. + */ +static int bcm_cpu_on(struct udevice *dev) +{ + struct bcm_plat *plat = dev_get_plat(dev); + ulong *start_address; + + if (plat->release_addr == ~0ULL) + return -ENODATA; + + start_address = map_physmem(plat->release_addr, sizeof(uintptr_t), MAP_NOCACHE); + + /* Point secondary CPU to U-Boot entry */ + *start_address = (uintptr_t)_start; + + /* Make sure the other CPUs see the written start address */ + if (!CONFIG_IS_ENABLED(SYS_DCACHE_OFF)) + flush_dcache_all(); + + /* Send an event to wake up the secondary CPU. */ + asm("dsb ishst\n" + "sev"); + + unmap_physmem(start_address, MAP_NOCACHE); + + return 0; +} + +static const struct cpu_ops cpu_bcm_ops = { + .get_desc = cpu_bcm_get_desc, + .get_info = cpu_bcm_get_info, + .get_count = cpu_bcm_get_count, + .get_vendor = cpu_bcm_get_vendor, + .is_current = cpu_bcm_is_current, +}; + +static const struct udevice_id cpu_bcm_ids[] = { + { .compatible = "arm,cortex-a53" }, /* RPi 3 */ + { .compatible = "arm,cortex-a72" }, /* RPi 4 */ + { } +}; + +static int bcm_cpu_bind(struct udevice *dev) +{ + struct cpu_plat *plat = dev_get_parent_plat(dev); + + plat->cpu_id = dev_read_addr(dev); + + return 0; +} + +/** + * bcm_cpu_of_to_plat - Gather spin-table release address + * + * Read the spin-table release address to allow all seconary CPUs to enter + * U-Boot when necessary. + * + * @dev: Device to start + */ +static int bcm_cpu_of_to_plat(struct udevice *dev) +{ + struct bcm_plat *plat = dev_get_plat(dev); + const char *prop; + + if (CONFIG_IS_ENABLED(ARMV8_MULTIENTRY)) { + plat->release_addr = ~0ULL; + + prop = dev_read_string(dev, "enable-method"); + if (!prop || strcmp(prop, "spin-table")) + return -ENODEV; + + plat->release_addr = dev_read_u64_default(dev, "cpu-release-addr", ~0ULL); + + if (plat->release_addr == ~0ULL) + return -ENODEV; + } + + return 0; +} + +static int bcm_cpu_probe(struct udevice *dev) +{ + struct cpu_plat *plat = dev_get_parent_plat(dev); + struct clk clk; + int ret; + + /* Get a clock if it exists */ + ret = clk_get_by_index(dev, 0, &clk); + if (!ret) { + ret = clk_enable(&clk); + if (ret && (ret != -ENOSYS || ret != -EOPNOTSUPP)) + return ret; + ret = clk_get_rate(&clk); + if (IS_ERR_VALUE(ret)) + return ret; + plat->timebase_freq = ret; + } + + /* + * The armstub holds the secondary CPUs in a spinloop. When + * ARMV8_MULTIENTRY is enabled release the secondary CPUs and + * let them enter U-Boot as well. + */ + if (CONFIG_IS_ENABLED(ARMV8_MULTIENTRY)) { + ret = bcm_cpu_on(dev); + if (ret) + return ret; + } + + return ret; +} + +struct acpi_ops bcm283x_cpu_acpi_ops = { + .fill_ssdt = armv8_cpu_fill_ssdt, + .fill_madt = armv8_cpu_fill_madt, +}; + +U_BOOT_DRIVER(cpu_bcm_drv) = { + .name = "bcm283x_cpu", + .id = UCLASS_CPU, + .of_match = cpu_bcm_ids, + .ops = &cpu_bcm_ops, + .probe = bcm_cpu_probe, + .bind = bcm_cpu_bind, + .of_to_plat = bcm_cpu_of_to_plat, + .plat_auto = sizeof(struct bcm_plat), + ACPI_OPS_PTR(&bcm283x_cpu_acpi_ops) +};