mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-15 08:14:15 +08:00
643e12da4a
When a CPU is marked as disabled, but online capable in the MADT, PSCI applies some firmware policy to control when it can be brought online. PSCI returns DENIED to a CPU_ON request if this is not currently permitted. The OS can learn the current policy from the _STA enabled bit. Handle the PSCI DENIED return code gracefully instead of printing an error. Note the alternatives to the PSCI cpu_boot() callback do not return -EPERM so the change in smp.c has no affect. See https://developer.arm.com/documentation/den0022/f/?lang=en page 58. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> [ morse: Rewrote commit message ] Signed-off-by: James Morse <james.morse@arm.com> Tested-by: Miguel Luis <miguel.luis@oracle.com> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com> Tested-by: Jianyong Wu <jianyong.wu@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20240529133446.28446-16-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
125 lines
2.6 KiB
C
125 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
*
|
|
* Copyright (C) 2013 ARM Limited
|
|
*
|
|
* Author: Will Deacon <will.deacon@arm.com>
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "psci: " fmt
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/of.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/psci.h>
|
|
#include <linux/mm.h>
|
|
|
|
#include <uapi/linux/psci.h>
|
|
|
|
#include <asm/cpu_ops.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/smp_plat.h>
|
|
|
|
static int __init cpu_psci_cpu_init(unsigned int cpu)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int __init cpu_psci_cpu_prepare(unsigned int cpu)
|
|
{
|
|
if (!psci_ops.cpu_on) {
|
|
pr_err("no cpu_on method, not booting CPU%d\n", cpu);
|
|
return -ENODEV;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cpu_psci_cpu_boot(unsigned int cpu)
|
|
{
|
|
phys_addr_t pa_secondary_entry = __pa_symbol(secondary_entry);
|
|
int err = psci_ops.cpu_on(cpu_logical_map(cpu), pa_secondary_entry);
|
|
if (err && err != -EPERM)
|
|
pr_err("failed to boot CPU%d (%d)\n", cpu, err);
|
|
|
|
return err;
|
|
}
|
|
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
static bool cpu_psci_cpu_can_disable(unsigned int cpu)
|
|
{
|
|
return !psci_tos_resident_on(cpu);
|
|
}
|
|
|
|
static int cpu_psci_cpu_disable(unsigned int cpu)
|
|
{
|
|
/* Fail early if we don't have CPU_OFF support */
|
|
if (!psci_ops.cpu_off)
|
|
return -EOPNOTSUPP;
|
|
|
|
/* Trusted OS will deny CPU_OFF */
|
|
if (psci_tos_resident_on(cpu))
|
|
return -EPERM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cpu_psci_cpu_die(unsigned int cpu)
|
|
{
|
|
/*
|
|
* There are no known implementations of PSCI actually using the
|
|
* power state field, pass a sensible default for now.
|
|
*/
|
|
u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN <<
|
|
PSCI_0_2_POWER_STATE_TYPE_SHIFT;
|
|
|
|
psci_ops.cpu_off(state);
|
|
}
|
|
|
|
static int cpu_psci_cpu_kill(unsigned int cpu)
|
|
{
|
|
int err;
|
|
unsigned long start, end;
|
|
|
|
if (!psci_ops.affinity_info)
|
|
return 0;
|
|
/*
|
|
* cpu_kill could race with cpu_die and we can
|
|
* potentially end up declaring this cpu undead
|
|
* while it is dying. So, try again a few times.
|
|
*/
|
|
|
|
start = jiffies;
|
|
end = start + msecs_to_jiffies(100);
|
|
do {
|
|
err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
|
|
if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
|
|
pr_info("CPU%d killed (polled %d ms)\n", cpu,
|
|
jiffies_to_msecs(jiffies - start));
|
|
return 0;
|
|
}
|
|
|
|
usleep_range(100, 1000);
|
|
} while (time_before(jiffies, end));
|
|
|
|
pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
|
|
cpu, err);
|
|
return -ETIMEDOUT;
|
|
}
|
|
#endif
|
|
|
|
const struct cpu_operations cpu_psci_ops = {
|
|
.name = "psci",
|
|
.cpu_init = cpu_psci_cpu_init,
|
|
.cpu_prepare = cpu_psci_cpu_prepare,
|
|
.cpu_boot = cpu_psci_cpu_boot,
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
.cpu_can_disable = cpu_psci_cpu_can_disable,
|
|
.cpu_disable = cpu_psci_cpu_disable,
|
|
.cpu_die = cpu_psci_cpu_die,
|
|
.cpu_kill = cpu_psci_cpu_kill,
|
|
#endif
|
|
};
|
|
|