From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt

---
 kernel/arch/riscv/kernel/cpu.c |  101 +++++++++++++++++++++++++++++++-------------------
 1 files changed, 63 insertions(+), 38 deletions(-)

diff --git a/kernel/arch/riscv/kernel/cpu.c b/kernel/arch/riscv/kernel/cpu.c
index ca6c81e..6d59e69 100644
--- a/kernel/arch/riscv/kernel/cpu.c
+++ b/kernel/arch/riscv/kernel/cpu.c
@@ -1,62 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2012 Regents of the University of California
- *
- *   This program is free software; you can redistribute it and/or
- *   modify it under the terms of the GNU General Public License
- *   as published by the Free Software Foundation, version 2.
- *
- *   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.
  */
 
 #include <linux/init.h>
 #include <linux/seq_file.h>
 #include <linux/of.h>
+#include <asm/smp.h>
 
-/* Return -1 if not a valid hart */
-int riscv_of_processor_hart(struct device_node *node)
+/*
+ * Returns the hart ID of the given device tree node, or -ENODEV if the node
+ * isn't an enabled and valid RISC-V hart node.
+ */
+int riscv_of_processor_hartid(struct device_node *node)
 {
-	const char *isa, *status;
+	const char *isa;
 	u32 hart;
 
 	if (!of_device_is_compatible(node, "riscv")) {
 		pr_warn("Found incompatible CPU\n");
-		return -(ENODEV);
+		return -ENODEV;
 	}
 
 	if (of_property_read_u32(node, "reg", &hart)) {
 		pr_warn("Found CPU without hart ID\n");
-		return -(ENODEV);
-	}
-	if (hart >= NR_CPUS) {
-		pr_info("Found hart ID %d, which is above NR_CPUs.  Disabling this hart\n", hart);
-		return -(ENODEV);
+		return -ENODEV;
 	}
 
-	if (of_property_read_string(node, "status", &status)) {
-		pr_warn("CPU with hartid=%d has no \"status\" property\n", hart);
-		return -(ENODEV);
-	}
-	if (strcmp(status, "okay")) {
-		pr_info("CPU with hartid=%d has a non-okay status of \"%s\"\n", hart, status);
-		return -(ENODEV);
+	if (!of_device_is_available(node)) {
+		pr_info("CPU with hartid=%d is not available\n", hart);
+		return -ENODEV;
 	}
 
 	if (of_property_read_string(node, "riscv,isa", &isa)) {
 		pr_warn("CPU with hartid=%d has no \"riscv,isa\" property\n", hart);
-		return -(ENODEV);
+		return -ENODEV;
 	}
 	if (isa[0] != 'r' || isa[1] != 'v') {
 		pr_warn("CPU with hartid=%d has an invalid ISA of \"%s\"\n", hart, isa);
-		return -(ENODEV);
+		return -ENODEV;
 	}
 
 	return hart;
 }
 
+/*
+ * Find hart ID of the CPU DT node under which given DT node falls.
+ *
+ * To achieve this, we walk up the DT tree until we find an active
+ * RISC-V core (HART) node and extract the cpuid from it.
+ */
+int riscv_of_parent_hartid(struct device_node *node)
+{
+	for (; node; node = node->parent) {
+		if (of_device_is_compatible(node, "riscv"))
+			return riscv_of_processor_hartid(node);
+	}
+
+	return -1;
+}
+
 #ifdef CONFIG_PROC_FS
+
+static void print_isa(struct seq_file *f, const char *isa)
+{
+	/* Print the entire ISA as it is */
+	seq_puts(f, "isa\t\t: ");
+	seq_write(f, isa, strlen(isa));
+	seq_puts(f, "\n");
+}
+
+static void print_mmu(struct seq_file *f, const char *mmu_type)
+{
+#if defined(CONFIG_32BIT)
+	if (strcmp(mmu_type, "riscv,sv32") != 0)
+		return;
+#elif defined(CONFIG_64BIT)
+	if (strcmp(mmu_type, "riscv,sv39") != 0 &&
+	    strcmp(mmu_type, "riscv,sv48") != 0)
+		return;
+#endif
+
+	seq_printf(f, "mmu\t\t: %s\n", mmu_type+6);
+}
 
 static void *c_start(struct seq_file *m, loff_t *pos)
 {
@@ -78,22 +104,21 @@
 
 static int c_show(struct seq_file *m, void *v)
 {
-	unsigned long hart_id = (unsigned long)v - 1;
-	struct device_node *node = of_get_cpu_node(hart_id, NULL);
+	unsigned long cpu_id = (unsigned long)v - 1;
+	struct device_node *node = of_get_cpu_node(cpu_id, NULL);
 	const char *compat, *isa, *mmu;
 
-	seq_printf(m, "hart\t: %lu\n", hart_id);
-	if (!of_property_read_string(node, "riscv,isa", &isa)
-	    && isa[0] == 'r'
-	    && isa[1] == 'v')
-		seq_printf(m, "isa\t: %s\n", isa);
-	if (!of_property_read_string(node, "mmu-type", &mmu)
-	    && !strncmp(mmu, "riscv,", 6))
-		seq_printf(m, "mmu\t: %s\n", mmu+6);
+	seq_printf(m, "processor\t: %lu\n", cpu_id);
+	seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id));
+	if (!of_property_read_string(node, "riscv,isa", &isa))
+		print_isa(m, isa);
+	if (!of_property_read_string(node, "mmu-type", &mmu))
+		print_mmu(m, mmu);
 	if (!of_property_read_string(node, "compatible", &compat)
 	    && strcmp(compat, "riscv"))
-		seq_printf(m, "uarch\t: %s\n", compat);
+		seq_printf(m, "uarch\t\t: %s\n", compat);
 	seq_puts(m, "\n");
+	of_node_put(node);
 
 	return 0;
 }

--
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