mirror of
https://github.com/torvalds/linux.git
synced 2024-11-16 09:02:00 +00:00
4b3dc9679c
Nobody seems to be producing !SMP systems anymore, so this is just becoming a source of kernel bugs, particularly if people want to use coherent DMA with non-shared pages. This patch forces CONFIG_SMP=y for arm64, removing a modest amount of code in the process. Signed-off-by: Will Deacon <will.deacon@arm.com>
102 lines
2.4 KiB
C
102 lines
2.4 KiB
C
/*
|
|
* CPU kernel entry/exit control
|
|
*
|
|
* Copyright (C) 2013 ARM Ltd.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <linux/acpi.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/of.h>
|
|
#include <linux/string.h>
|
|
#include <asm/acpi.h>
|
|
#include <asm/cpu_ops.h>
|
|
#include <asm/smp_plat.h>
|
|
|
|
extern const struct cpu_operations smp_spin_table_ops;
|
|
extern const struct cpu_operations cpu_psci_ops;
|
|
|
|
const struct cpu_operations *cpu_ops[NR_CPUS];
|
|
|
|
static const struct cpu_operations *supported_cpu_ops[] __initconst = {
|
|
&smp_spin_table_ops,
|
|
&cpu_psci_ops,
|
|
NULL,
|
|
};
|
|
|
|
static const struct cpu_operations * __init cpu_get_ops(const char *name)
|
|
{
|
|
const struct cpu_operations **ops = supported_cpu_ops;
|
|
|
|
while (*ops) {
|
|
if (!strcmp(name, (*ops)->name))
|
|
return *ops;
|
|
|
|
ops++;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static const char *__init cpu_read_enable_method(int cpu)
|
|
{
|
|
const char *enable_method;
|
|
|
|
if (acpi_disabled) {
|
|
struct device_node *dn = of_get_cpu_node(cpu, NULL);
|
|
|
|
if (!dn) {
|
|
if (!cpu)
|
|
pr_err("Failed to find device node for boot cpu\n");
|
|
return NULL;
|
|
}
|
|
|
|
enable_method = of_get_property(dn, "enable-method", NULL);
|
|
if (!enable_method) {
|
|
/*
|
|
* The boot CPU may not have an enable method (e.g.
|
|
* when spin-table is used for secondaries).
|
|
* Don't warn spuriously.
|
|
*/
|
|
if (cpu != 0)
|
|
pr_err("%s: missing enable-method property\n",
|
|
dn->full_name);
|
|
}
|
|
} else {
|
|
enable_method = acpi_get_enable_method(cpu);
|
|
if (!enable_method)
|
|
pr_err("Unsupported ACPI enable-method\n");
|
|
}
|
|
|
|
return enable_method;
|
|
}
|
|
/*
|
|
* Read a cpu's enable method and record it in cpu_ops.
|
|
*/
|
|
int __init cpu_read_ops(int cpu)
|
|
{
|
|
const char *enable_method = cpu_read_enable_method(cpu);
|
|
|
|
if (!enable_method)
|
|
return -ENODEV;
|
|
|
|
cpu_ops[cpu] = cpu_get_ops(enable_method);
|
|
if (!cpu_ops[cpu]) {
|
|
pr_warn("Unsupported enable-method: %s\n", enable_method);
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
return 0;
|
|
}
|