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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/arm64/kernel/psci.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kernel/psci.c')
-rw-r--r--arch/arm64/kernel/psci.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
new file mode 100644
index 0000000000..29a8e444db
--- /dev/null
+++ b/arch/arm64/kernel/psci.c
@@ -0,0 +1,124 @@
+// 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)
+ 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
+};
+