130 lines
2.9 KiB
C
130 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* HSM extension and cpu_ops implementation.
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*
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* Copyright (c) 2020 Western Digital Corporation or its affiliates.
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*/
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/sched/task_stack.h>
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#include <asm/cpu_ops.h>
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#include <asm/cpu_ops_sbi.h>
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#include <asm/sbi.h>
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#include <asm/smp.h>
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extern char secondary_start_sbi[];
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const struct cpu_operations cpu_ops_sbi;
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/*
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* Ordered booting via HSM brings one cpu at a time. However, cpu hotplug can
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* be invoked from multiple threads in parallel. Define a per cpu data
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* to handle that.
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*/
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static DEFINE_PER_CPU(struct sbi_hart_boot_data, boot_data);
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static int sbi_hsm_hart_start(unsigned long hartid, unsigned long saddr,
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unsigned long priv)
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{
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struct sbiret ret;
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ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_START,
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hartid, saddr, priv, 0, 0, 0);
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if (ret.error)
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return sbi_err_map_linux_errno(ret.error);
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else
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return 0;
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}
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#ifdef CONFIG_HOTPLUG_CPU
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static int sbi_hsm_hart_stop(void)
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{
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struct sbiret ret;
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ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STOP, 0, 0, 0, 0, 0, 0);
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if (ret.error)
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return sbi_err_map_linux_errno(ret.error);
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else
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return 0;
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}
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static int sbi_hsm_hart_get_status(unsigned long hartid)
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{
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struct sbiret ret;
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ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_STATUS,
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hartid, 0, 0, 0, 0, 0);
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if (ret.error)
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return sbi_err_map_linux_errno(ret.error);
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else
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return ret.value;
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}
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#endif
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static int sbi_cpu_start(unsigned int cpuid, struct task_struct *tidle)
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{
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unsigned long boot_addr = __pa_symbol(secondary_start_sbi);
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unsigned long hartid = cpuid_to_hartid_map(cpuid);
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unsigned long hsm_data;
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struct sbi_hart_boot_data *bdata = &per_cpu(boot_data, cpuid);
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/* Make sure tidle is updated */
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smp_mb();
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bdata->task_ptr = tidle;
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bdata->stack_ptr = task_stack_page(tidle) + THREAD_SIZE;
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/* Make sure boot data is updated */
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smp_mb();
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hsm_data = __pa(bdata);
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return sbi_hsm_hart_start(hartid, boot_addr, hsm_data);
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}
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static int sbi_cpu_prepare(unsigned int cpuid)
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{
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if (!cpu_ops_sbi.cpu_start) {
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pr_err("cpu start method not defined for CPU [%d]\n", cpuid);
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return -ENODEV;
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}
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return 0;
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}
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#ifdef CONFIG_HOTPLUG_CPU
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static int sbi_cpu_disable(unsigned int cpuid)
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{
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if (!cpu_ops_sbi.cpu_stop)
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return -EOPNOTSUPP;
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return 0;
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}
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static void sbi_cpu_stop(void)
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{
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int ret;
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ret = sbi_hsm_hart_stop();
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pr_crit("Unable to stop the cpu %u (%d)\n", smp_processor_id(), ret);
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}
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static int sbi_cpu_is_stopped(unsigned int cpuid)
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{
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int rc;
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unsigned long hartid = cpuid_to_hartid_map(cpuid);
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rc = sbi_hsm_hart_get_status(hartid);
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if (rc == SBI_HSM_STATE_STOPPED)
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return 0;
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return rc;
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}
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#endif
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const struct cpu_operations cpu_ops_sbi = {
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.name = "sbi",
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.cpu_prepare = sbi_cpu_prepare,
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.cpu_start = sbi_cpu_start,
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#ifdef CONFIG_HOTPLUG_CPU
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.cpu_disable = sbi_cpu_disable,
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.cpu_stop = sbi_cpu_stop,
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.cpu_is_stopped = sbi_cpu_is_stopped,
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#endif
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};
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