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 Signed-off-by: Patrick Rudolph <[email protected]> Cc: Matthias Brugger <[email protected]> Cc: Peter Robinson <[email protected]> Cc: Tom Rini <[email protected]> --- arch/arm/mach-bcm283x/Kconfig | 2 ++ arch/arm/mach-bcm283x/init.c | 47 +++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+) diff --git a/arch/arm/mach-bcm283x/Kconfig b/arch/arm/mach-bcm283x/Kconfig index b3287ce8bc..de783aa8f5 100644 --- a/arch/arm/mach-bcm283x/Kconfig +++ b/arch/arm/mach-bcm283x/Kconfig @@ -12,6 +12,7 @@ config BCM2836 config BCM2837 bool "Broadcom BCM2837 SoC support" depends on ARCH_BCM283X + select ARCH_EARLY_INIT_R config BCM2837_32B bool "Broadcom BCM2837 SoC 32-bit support" @@ -29,6 +30,7 @@ config BCM2837_64B config BCM2711 bool "Broadcom BCM2711 SoC support" depends on ARCH_BCM283X + select ARCH_EARLY_INIT_R config BCM2711_32B bool "Broadcom BCM2711 SoC 32-bit support" diff --git a/arch/arm/mach-bcm283x/init.c b/arch/arm/mach-bcm283x/init.c index 80a10f2212..f6ccc76f39 100644 --- a/arch/arm/mach-bcm283x/init.c +++ b/arch/arm/mach-bcm283x/init.c @@ -7,6 +7,7 @@ */ #include <acpi/acpi_table.h> +#include <asm-generic/sections.h> #include <cpu_func.h> #include <init.h> #include <dm/device.h> @@ -201,6 +202,52 @@ int mach_cpu_init(void) "brcm,bcm2712-pm"); if (offset > soc) rpi_wdog_base = fdt_get_base_address(gd->fdt_blob, offset); + return 0; +} + +int arch_early_init_r(void) +{ + int cpus, offset; + const char *prop; + u64 release_addr64; + uintptr_t *start_address; + + if (CONFIG_IS_ENABLED(ARMV8_MULTIENTRY)) { + /* + * Release CPUs from reset after u-boot has been relocated. + */ + cpus = fdt_path_offset(gd->fdt_blob, "/cpus"); + if (cpus < 0) + return -ENODEV; + + for (offset = fdt_first_subnode(gd->fdt_blob, cpus); + offset >= 0; + offset = fdt_next_subnode(gd->fdt_blob, offset)) { + prop = fdt_getprop(gd->fdt_blob, offset, "device_type", NULL); + if (!prop || strcmp(prop, "cpu")) + continue; + + prop = fdt_getprop(gd->fdt_blob, offset, "enable-method", NULL); + if (!prop || strcmp(prop, "spin-table")) + continue; + + release_addr64 = fdtdec_get_uint64(gd->fdt_blob, offset, + "cpu-release-addr", ~0ULL); + if (release_addr64 == ~0ULL) + continue; + + /* Point to U-Boot start */ + start_address = (uintptr_t *)(uintptr_t)release_addr64; + *start_address = (uintptr_t)_start; + + if (!CONFIG_IS_ENABLED(SYS_DCACHE_OFF)) + flush_dcache_range(release_addr64, + release_addr64 + sizeof(uintptr_t)); + /* Send an event to wake up the secondary CPU. */ + asm("dsb ishst\n" + "sev"); + } + } return 0; } -- 2.45.2
