From: Sam Day <[email protected]> Most MSM8916 devices lack PSCI support, instead they're brought online with a qcom SCM call to set the boot address, and some register poking of the APCS register block.
Signed-off-by: Sam Day <[email protected]> --- arch/arm/mach-snapdragon/Makefile | 1 + arch/arm/mach-snapdragon/msm8916-smp.c | 138 +++++++++++++++++++++++++++++++++ 2 files changed, 139 insertions(+) diff --git a/arch/arm/mach-snapdragon/Makefile b/arch/arm/mach-snapdragon/Makefile index 343e825c6fd..584b8af055a 100644 --- a/arch/arm/mach-snapdragon/Makefile +++ b/arch/arm/mach-snapdragon/Makefile @@ -5,3 +5,4 @@ obj-y += board.o obj-$(CONFIG_EFI_HAVE_CAPSULE_SUPPORT) += capsule_update.o obj-$(CONFIG_OF_LIVE) += of_fixup.o +obj-$(CONFIG_ARMV8_SPIN_TABLE) += msm8916-smp.o diff --git a/arch/arm/mach-snapdragon/msm8916-smp.c b/arch/arm/mach-snapdragon/msm8916-smp.c new file mode 100644 index 00000000000..24f5590ccc3 --- /dev/null +++ b/arch/arm/mach-snapdragon/msm8916-smp.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * On MSM8916 devices that lack a PSCI implementation, firing up the secondary + * cores requires a call to TZ to set the boot address, and some poking of ACPS + * register block. + * + * Copyright (c) 2025 Linaro Ltd. + */ + +#include <asm/io.h> +#include <asm/spin_table.h> +#include <asm/system.h> +#include <cpu_func.h> +#include <dm/ofnode.h> +#include <firmware/qcom/scm.h> +#include <linux/arm-smccc.h> +#include <linux/delay.h> + +#define APCS_CPU_PWR_CTL 0x04 +#define CORE_PWRD_UP BIT(7) +#define COREPOR_RST BIT(5) +#define CORE_RST BIT(4) +#define CORE_MEM_HS BIT(3) +#define CORE_MEM_CLAMP BIT(1) +#define CLAMP BIT(0) + +#define APC_PWR_GATE_CTL 0x14 +#define GDHS_CNT_SHIFT 24 +#define GDHS_EN BIT(0) + +static void qcom_boot_cortex_a53(phys_addr_t acc_base) +{ + u32 reg_val; + + /* Put the CPU into reset. */ + reg_val = CORE_RST | COREPOR_RST | CLAMP | CORE_MEM_CLAMP; + writel(reg_val, acc_base + APCS_CPU_PWR_CTL); + + /* Turn on the GDHS and set the GDHS_CNT to 16 XO clock cycles */ + writel(GDHS_EN | (0x10 << GDHS_CNT_SHIFT), acc_base + APC_PWR_GATE_CTL); + /* Wait for the GDHS to settle */ + udelay(2); + + reg_val &= ~CORE_MEM_CLAMP; + writel(reg_val, acc_base + APCS_CPU_PWR_CTL); + reg_val |= CORE_MEM_HS; + writel(reg_val, acc_base + APCS_CPU_PWR_CTL); + udelay(2); + + reg_val &= ~CLAMP; + writel(reg_val, acc_base + APCS_CPU_PWR_CTL); + udelay(2); + + /* Release CPU out of reset and bring it to life. */ + reg_val &= ~(CORE_RST | COREPOR_RST); + writel(reg_val, acc_base + APCS_CPU_PWR_CTL); + reg_val |= CORE_PWRD_UP; + writel(reg_val, acc_base + APCS_CPU_PWR_CTL); +} + +static int qcom_scm_set_boot_addr_mc(void *entry, unsigned int flags) +{ + struct qcom_scm_desc desc = { + .svc = QCOM_SCM_SVC_BOOT, + .cmd = QCOM_SCM_BOOT_SET_ADDR_MC, + .owner = ARM_SMCCC_OWNER_SIP, + .arginfo = QCOM_SCM_ARGS(6), + .args = { + (u64)entry, + /* Apply to all CPUs in all affinity levels */ + ~0ULL, ~0ULL, ~0ULL, ~0ULL, + flags, + }, + }; + + if (!qcom_scm_is_call_available(desc.svc, desc.cmd)) + return -EOPNOTSUPP; + + return qcom_scm_call(&desc, NULL); +} + +static bool boot_addr_set; + +int spin_table_boot_cpu(void *fdt, int cpu_offset) +{ + struct fdtdec_phandle_args acc; + u32 mpidr_aff, acc_base, reg; + int ret; + + if (fdt_node_check_compatible(fdt, 0, "qcom,msm8916")) + return 0; + + reg = fdtdec_get_uint(fdt, cpu_offset, "reg", 0); + + if (fdt_node_check_compatible(fdt, cpu_offset, "arm,cortex-a53")) { + log_warning("CPU%d is not arm,cortex-a53 compatible\n", reg); + return -EINVAL; + } + + if (!boot_addr_set) { + debug("Setting CPU boot address to 0x%llx\n", + (phys_addr_t)&spin_table_reserve_begin); + ret = qcom_scm_set_boot_addr_mc(&spin_table_reserve_begin, + QCOM_SCM_BOOT_MC_FLAG_AARCH64 | + QCOM_SCM_BOOT_MC_FLAG_COLDBOOT); + if (ret) { + log_err("Failed to set CPU boot addr: %d\n", ret); + return ret; + } + + boot_addr_set = true; + } + + mpidr_aff = read_mpidr() & 0xffffff; + + if (reg == mpidr_aff) { + debug("Skipping boot of current CPU%d\n", reg); + return 0; + } + + ret = fdtdec_parse_phandle_with_args(fdt, cpu_offset, "qcom,acc", + NULL, 0, 0, &acc); + if (ret) { + log_err("Failed to parse qcom,acc phandle: %d\n", reg); + return ret; + } + + acc_base = fdtdec_get_addr_size_auto_noparent(fdt, acc.node, "reg", 0, + NULL, true); + if (!acc_base) { + log_err("Failed to parse qcom,acc regbase\n"); + return -EINVAL; + } + + log_info("Booting CPU%d @ 0x%x\n", reg, acc_base); + qcom_boot_cortex_a53(acc_base); + return 0; +} -- 2.54.0
