From 10ebd8556b7990499c896a550e3d416b444211e6 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 02:23:07 +0000
Subject: [PATCH] add led
---
kernel/arch/arm64/kernel/paravirt.c | 170 +++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 160 insertions(+), 10 deletions(-)
diff --git a/kernel/arch/arm64/kernel/paravirt.c b/kernel/arch/arm64/kernel/paravirt.c
index 53f371e..69ec670 100644
--- a/kernel/arch/arm64/kernel/paravirt.c
+++ b/kernel/arch/arm64/kernel/paravirt.c
@@ -1,25 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
- * 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.
*
* Copyright (C) 2013 Citrix Systems
*
* Author: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
*/
+#define pr_fmt(fmt) "arm-pv: " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/cpuhotplug.h>
#include <linux/export.h>
+#include <linux/io.h>
#include <linux/jump_label.h>
+#include <linux/printk.h>
+#include <linux/psci.h>
+#include <linux/reboot.h>
+#include <linux/slab.h>
#include <linux/types.h>
+
#include <asm/paravirt.h>
+#include <asm/pvclock-abi.h>
+#include <asm/smp_plat.h>
struct static_key paravirt_steal_enabled;
struct static_key paravirt_steal_rq_enabled;
-struct pv_time_ops pv_time_ops;
-EXPORT_SYMBOL_GPL(pv_time_ops);
+struct paravirt_patch_template pv_ops;
+EXPORT_SYMBOL_GPL(pv_ops);
+
+struct pv_time_stolen_time_region {
+ struct pvclock_vcpu_stolen_time __rcu *kaddr;
+};
+
+static DEFINE_PER_CPU(struct pv_time_stolen_time_region, stolen_time_region);
+
+static bool steal_acc = true;
+static int __init parse_no_stealacc(char *arg)
+{
+ steal_acc = false;
+ return 0;
+}
+
+early_param("no-steal-acc", parse_no_stealacc);
+
+/* return stolen time in ns by asking the hypervisor */
+static u64 pv_steal_clock(int cpu)
+{
+ struct pvclock_vcpu_stolen_time *kaddr = NULL;
+ struct pv_time_stolen_time_region *reg;
+ u64 ret = 0;
+
+ reg = per_cpu_ptr(&stolen_time_region, cpu);
+
+ /*
+ * paravirt_steal_clock() may be called before the CPU
+ * online notification callback runs. Until the callback
+ * has run we just return zero.
+ */
+ rcu_read_lock();
+ kaddr = rcu_dereference(reg->kaddr);
+ if (!kaddr) {
+ rcu_read_unlock();
+ return 0;
+ }
+
+ ret = le64_to_cpu(READ_ONCE(kaddr->stolen_time));
+ rcu_read_unlock();
+ return ret;
+}
+
+static int stolen_time_cpu_down_prepare(unsigned int cpu)
+{
+ struct pvclock_vcpu_stolen_time *kaddr = NULL;
+ struct pv_time_stolen_time_region *reg;
+
+ reg = this_cpu_ptr(&stolen_time_region);
+ if (!reg->kaddr)
+ return 0;
+
+ kaddr = rcu_replace_pointer(reg->kaddr, NULL, true);
+ synchronize_rcu();
+ memunmap(kaddr);
+
+ return 0;
+}
+
+static int stolen_time_cpu_online(unsigned int cpu)
+{
+ struct pvclock_vcpu_stolen_time *kaddr = NULL;
+ struct pv_time_stolen_time_region *reg;
+ struct arm_smccc_res res;
+
+ reg = this_cpu_ptr(&stolen_time_region);
+
+ arm_smccc_1_1_invoke(ARM_SMCCC_HV_PV_TIME_ST, &res);
+
+ if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
+ return -EINVAL;
+
+ kaddr = memremap(res.a0,
+ sizeof(struct pvclock_vcpu_stolen_time),
+ MEMREMAP_WB);
+
+ rcu_assign_pointer(reg->kaddr, kaddr);
+
+ if (!reg->kaddr) {
+ pr_warn("Failed to map stolen time data structure\n");
+ return -ENOMEM;
+ }
+
+ if (le32_to_cpu(kaddr->revision) != 0 ||
+ le32_to_cpu(kaddr->attributes) != 0) {
+ pr_warn_once("Unexpected revision or attributes in stolen time data\n");
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
+static int __init pv_time_init_stolen_time(void)
+{
+ int ret;
+
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+ "hypervisor/arm/pvtime:online",
+ stolen_time_cpu_online,
+ stolen_time_cpu_down_prepare);
+ if (ret < 0)
+ return ret;
+ return 0;
+}
+
+static bool __init has_pv_steal_clock(void)
+{
+ struct arm_smccc_res res;
+
+ /* To detect the presence of PV time support we require SMCCC 1.1+ */
+ if (arm_smccc_1_1_get_conduit() == SMCCC_CONDUIT_NONE)
+ return false;
+
+ arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+ ARM_SMCCC_HV_PV_TIME_FEATURES, &res);
+
+ if (res.a0 != SMCCC_RET_SUCCESS)
+ return false;
+
+ arm_smccc_1_1_invoke(ARM_SMCCC_HV_PV_TIME_FEATURES,
+ ARM_SMCCC_HV_PV_TIME_ST, &res);
+
+ return (res.a0 == SMCCC_RET_SUCCESS);
+}
+
+int __init pv_time_init(void)
+{
+ int ret;
+
+ if (!has_pv_steal_clock())
+ return 0;
+
+ ret = pv_time_init_stolen_time();
+ if (ret)
+ return ret;
+
+ pv_ops.time.steal_clock = pv_steal_clock;
+
+ static_key_slow_inc(¶virt_steal_enabled);
+ if (steal_acc)
+ static_key_slow_inc(¶virt_steal_rq_enabled);
+
+ pr_info("using stolen time PV\n");
+
+ return 0;
+}
--
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