Hi Patrick,
On Sat, 27 Jul 2024 at 01:20, Patrick Rudolph
<patrick.rudo...@9elements.com> wrote:
>
> 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 <patrick.rudo...@9elements.com>
> Cc: Matthias Brugger <mbrug...@suse.com>
> Cc: Peter Robinson <pbrobin...@gmail.com>
> Cc: Tom Rini <tr...@konsulko.com>
> ---
> 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");
We should not go hacking around in the devicetree. We need a way to
handle this through driver model. See cpu.h and perhaps add a new
operation if needed?
> + 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
>
Regards,
Simon
