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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/riscv/kernel/cpu_ops_sbi.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/riscv/kernel/cpu_ops_sbi.c')
-rw-r--r-- | arch/riscv/kernel/cpu_ops_sbi.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/arch/riscv/kernel/cpu_ops_sbi.c b/arch/riscv/kernel/cpu_ops_sbi.c new file mode 100644 index 0000000000..efa0f08166 --- /dev/null +++ b/arch/riscv/kernel/cpu_ops_sbi.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * HSM extension and cpu_ops implementation. + * + * Copyright (c) 2020 Western Digital Corporation or its affiliates. + */ + +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/sched/task_stack.h> +#include <asm/cpu_ops.h> +#include <asm/cpu_ops_sbi.h> +#include <asm/sbi.h> +#include <asm/smp.h> + +extern char secondary_start_sbi[]; +const struct cpu_operations cpu_ops_sbi; + +/* + * Ordered booting via HSM brings one cpu at a time. However, cpu hotplug can + * be invoked from multiple threads in parallel. Define a per cpu data + * to handle that. + */ +static DEFINE_PER_CPU(struct sbi_hart_boot_data, boot_data); + +static int sbi_hsm_hart_start(unsigned long hartid, unsigned long saddr, + unsigned long priv) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_START, + hartid, saddr, priv, 0, 0, 0); + if (ret.error) + return sbi_err_map_linux_errno(ret.error); + else + return 0; +} + +#ifdef CONFIG_HOTPLUG_CPU +static int sbi_hsm_hart_stop(void) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STOP, 0, 0, 0, 0, 0, 0); + + if (ret.error) + return sbi_err_map_linux_errno(ret.error); + else + return 0; +} + +static int sbi_hsm_hart_get_status(unsigned long hartid) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STATUS, + hartid, 0, 0, 0, 0, 0); + if (ret.error) + return sbi_err_map_linux_errno(ret.error); + else + return ret.value; +} +#endif + +static int sbi_cpu_start(unsigned int cpuid, struct task_struct *tidle) +{ + unsigned long boot_addr = __pa_symbol(secondary_start_sbi); + unsigned long hartid = cpuid_to_hartid_map(cpuid); + unsigned long hsm_data; + struct sbi_hart_boot_data *bdata = &per_cpu(boot_data, cpuid); + + /* Make sure tidle is updated */ + smp_mb(); + bdata->task_ptr = tidle; + bdata->stack_ptr = task_stack_page(tidle) + THREAD_SIZE; + /* Make sure boot data is updated */ + smp_mb(); + hsm_data = __pa(bdata); + return sbi_hsm_hart_start(hartid, boot_addr, hsm_data); +} + +static int sbi_cpu_prepare(unsigned int cpuid) +{ + if (!cpu_ops_sbi.cpu_start) { + pr_err("cpu start method not defined for CPU [%d]\n", cpuid); + return -ENODEV; + } + return 0; +} + +#ifdef CONFIG_HOTPLUG_CPU +static int sbi_cpu_disable(unsigned int cpuid) +{ + if (!cpu_ops_sbi.cpu_stop) + return -EOPNOTSUPP; + return 0; +} + +static void sbi_cpu_stop(void) +{ + int ret; + + ret = sbi_hsm_hart_stop(); + pr_crit("Unable to stop the cpu %u (%d)\n", smp_processor_id(), ret); +} + +static int sbi_cpu_is_stopped(unsigned int cpuid) +{ + int rc; + unsigned long hartid = cpuid_to_hartid_map(cpuid); + + rc = sbi_hsm_hart_get_status(hartid); + + if (rc == SBI_HSM_STATE_STOPPED) + return 0; + return rc; +} +#endif + +const struct cpu_operations cpu_ops_sbi = { + .name = "sbi", + .cpu_prepare = sbi_cpu_prepare, + .cpu_start = sbi_cpu_start, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_disable = sbi_cpu_disable, + .cpu_stop = sbi_cpu_stop, + .cpu_is_stopped = sbi_cpu_is_stopped, +#endif +}; |