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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /arch/arm64/kernel/cpu_ops.c
parentInitial commit. (diff)
downloadlinux-upstream/5.10.209.tar.xz
linux-upstream/5.10.209.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kernel/cpu_ops.c')
-rw-r--r--arch/arm64/kernel/cpu_ops.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
new file mode 100644
index 000000000..e133011f6
--- /dev/null
+++ b/arch/arm64/kernel/cpu_ops.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CPU kernel entry/exit control
+ *
+ * Copyright (C) 2013 ARM Ltd.
+ */
+
+#include <linux/acpi.h>
+#include <linux/cache.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;
+#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
+extern const struct cpu_operations acpi_parking_protocol_ops;
+#endif
+extern const struct cpu_operations cpu_psci_ops;
+
+static const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
+
+static const struct cpu_operations *const dt_supported_cpu_ops[] __initconst = {
+ &smp_spin_table_ops,
+ &cpu_psci_ops,
+ NULL,
+};
+
+static const struct cpu_operations *const acpi_supported_cpu_ops[] __initconst = {
+#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
+ &acpi_parking_protocol_ops,
+#endif
+ &cpu_psci_ops,
+ NULL,
+};
+
+static const struct cpu_operations * __init cpu_get_ops(const char *name)
+{
+ const struct cpu_operations *const *ops;
+
+ ops = acpi_disabled ? dt_supported_cpu_ops : acpi_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("%pOF: missing enable-method property\n",
+ dn);
+ }
+ of_node_put(dn);
+ } else {
+ enable_method = acpi_get_enable_method(cpu);
+ if (!enable_method) {
+ /*
+ * In ACPI systems the boot CPU does not require
+ * checking the enable method since for some
+ * boot protocol (ie parking protocol) it need not
+ * be initialized. Don't warn spuriously.
+ */
+ if (cpu != 0)
+ pr_err("Unsupported ACPI enable-method\n");
+ }
+ }
+
+ return enable_method;
+}
+/*
+ * Read a cpu's enable method and record it in cpu_ops.
+ */
+int __init init_cpu_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;
+}
+
+const struct cpu_operations *get_cpu_ops(int cpu)
+{
+ return cpu_ops[cpu];
+}