kernel-fxtec-pro1x/arch/arm64/kernel/cpu_ops.c
Lorenzo Pieralisi 0f0783365c ARM64: kernel: unify ACPI and DT cpus initialization
The code that initializes cpus on arm64 is currently split in two
different code paths that carry out DT and ACPI cpus initialization.

Most of the code executing SMP initialization is common and should
be merged to reduce discrepancies between ACPI and DT initialization
and to have code initializing cpus in a single common place in the
kernel.

This patch refactors arm64 SMP cpus initialization code to merge
ACPI and DT boot paths in a common file and to create sanity
checks that can be reused by both boot methods.

Current code assumes PSCI is the only available boot method
when arm64 boots with ACPI; this can be easily extended if/when
the ACPI parking protocol is merged into the kernel.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Hanjun Guo <hanjun.guo@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Mark Rutland <mark.rutland@arm.com> [DT]
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-05-19 16:09:29 +01:00

103 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 = {
#ifdef CONFIG_SMP
&smp_spin_table_ops,
#endif
&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;
}