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e8765b265a
With the advent of CPU_HOTPLUG, the enable-method property for CPU0 may tells us something useful (i.e. how to hotplug it back on), so we must read it along with all the enable-method for all the other CPUs. Even on UP the enable-method may tell us useful information (e.g. if a core has some mechanism that might be usable for cpuidle), so we should always read it. This patch factors out the reading of the enable method, and ensures that CPU0's enable method is read regardless of whether the kernel is built with SMP support. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
100 lines
2.3 KiB
C
100 lines
2.3 KiB
C
/*
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* CPU kernel entry/exit control
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*
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* Copyright (C) 2013 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <asm/cpu_ops.h>
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#include <asm/smp_plat.h>
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#include <linux/errno.h>
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#include <linux/of.h>
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#include <linux/string.h>
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extern const struct cpu_operations smp_spin_table_ops;
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extern const struct cpu_operations cpu_psci_ops;
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const struct cpu_operations *cpu_ops[NR_CPUS];
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static const struct cpu_operations *supported_cpu_ops[] __initconst = {
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#ifdef CONFIG_SMP
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&smp_spin_table_ops,
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&cpu_psci_ops,
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#endif
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NULL,
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};
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static const struct cpu_operations * __init cpu_get_ops(const char *name)
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{
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const struct cpu_operations **ops = supported_cpu_ops;
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while (*ops) {
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if (!strcmp(name, (*ops)->name))
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return *ops;
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ops++;
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}
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return NULL;
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}
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/*
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* Read a cpu's enable method from the device tree and record it in cpu_ops.
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*/
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int __init cpu_read_ops(struct device_node *dn, int cpu)
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{
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const char *enable_method = of_get_property(dn, "enable-method", NULL);
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if (!enable_method) {
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/*
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* The boot CPU may not have an enable method (e.g. when
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* spin-table is used for secondaries). Don't warn spuriously.
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*/
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if (cpu != 0)
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pr_err("%s: missing enable-method property\n",
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dn->full_name);
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return -ENOENT;
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}
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cpu_ops[cpu] = cpu_get_ops(enable_method);
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if (!cpu_ops[cpu]) {
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pr_err("%s: invalid enable-method property: %s\n",
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dn->full_name, enable_method);
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return -EOPNOTSUPP;
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}
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return 0;
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}
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void __init cpu_read_bootcpu_ops(void)
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{
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struct device_node *dn = NULL;
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u64 mpidr = cpu_logical_map(0);
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while ((dn = of_find_node_by_type(dn, "cpu"))) {
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u64 hwid;
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const __be32 *prop;
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prop = of_get_property(dn, "reg", NULL);
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if (!prop)
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continue;
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hwid = of_read_number(prop, of_n_addr_cells(dn));
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if (hwid == mpidr) {
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cpu_read_ops(dn, 0);
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of_node_put(dn);
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return;
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}
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}
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}
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