riscv: cpu: Add 64bit hartid support on RV64

The hartid can be a 64bit value on RV64 platforms.

Add support for 64bit hartid in riscv_of_processor_hartid() and
update its callers.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20220527051743.2829940-5-sunilvl@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Author: vlsunil

arch/riscv/include/asm/processor.h

@@ -79,8 +79,8 @@ static inline void wait_for_interrupt(void)
 }
 
 struct device_node;
-int riscv_of_processor_hartid(struct device_node *node);
-int riscv_of_parent_hartid(struct device_node *node);
+int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
+int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
 
 extern void riscv_fill_hwcap(void);
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);

arch/riscv/kernel/cpu.c

@@ -14,37 +14,36 @@
  * 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)
+int riscv_of_processor_hartid(struct device_node *node, unsigned long *hart)
 {
 	const char *isa;
-	u32 hart;
 
 	if (!of_device_is_compatible(node, "riscv")) {
 		pr_warn("Found incompatible CPU\n");
 		return -ENODEV;
 	}
 
-	hart = of_get_cpu_hwid(node, 0);
-	if (hart == ~0U) {
+	*hart = (unsigned long) of_get_cpu_hwid(node, 0);
+	if (*hart == ~0UL) {
 		pr_warn("Found CPU without hart ID\n");
 		return -ENODEV;
 	}
 
 	if (!of_device_is_available(node)) {
-		pr_info("CPU with hartid=%d is not available\n", hart);
+		pr_info("CPU with hartid=%lu 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);
+		pr_warn("CPU with hartid=%lu has no \"riscv,isa\" property\n", *hart);
 		return -ENODEV;
 	}
 	if (isa[0] != 'r' || isa[1] != 'v') {
-		pr_warn("CPU with hartid=%d has an invalid ISA of \"%s\"\n", hart, isa);
+		pr_warn("CPU with hartid=%lu has an invalid ISA of \"%s\"\n", *hart, isa);
 		return -ENODEV;
 	}
 
-	return hart;
+	return 0;
 }
 
 /*
@@ -53,11 +52,16 @@ int riscv_of_processor_hartid(struct device_node *node)
  * 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)
+int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
 {
+	int rc;
+
 	for (; node; node = node->parent) {
-		if (of_device_is_compatible(node, "riscv"))
-			return riscv_of_processor_hartid(node);
+		if (of_device_is_compatible(node, "riscv")) {
+			rc = riscv_of_processor_hartid(node, hartid);
+			if (!rc)
+				return 0;
+		}
 	}
 
 	return -1;

arch/riscv/kernel/cpufeature.c

@@ -73,8 +73,9 @@ void __init riscv_fill_hwcap(void)
 	struct device_node *node;
 	const char *isa;
 	char print_str[NUM_ALPHA_EXTS + 1];
-	int i, j;
+	int i, j, rc;
 	static unsigned long isa2hwcap[256] = {0};
+	unsigned long hartid;
 
 	isa2hwcap['i'] = isa2hwcap['I'] = COMPAT_HWCAP_ISA_I;
 	isa2hwcap['m'] = isa2hwcap['M'] = COMPAT_HWCAP_ISA_M;
@@ -92,7 +93,8 @@ void __init riscv_fill_hwcap(void)
 		DECLARE_BITMAP(this_isa, RISCV_ISA_EXT_MAX);
 		const char *temp;
 
-		if (riscv_of_processor_hartid(node) < 0)
+		rc = riscv_of_processor_hartid(node, &hartid);
+		if (rc < 0)
 			continue;
 
 		if (of_property_read_string(node, "riscv,isa", &isa)) {

arch/riscv/kernel/smpboot.c

@@ -72,15 +72,16 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 void __init setup_smp(void)
 {
 	struct device_node *dn;
-	int hart;
+	unsigned long hart;
 	bool found_boot_cpu = false;
 	int cpuid = 1;
+	int rc;
 
 	cpu_set_ops(0);
 
 	for_each_of_cpu_node(dn) {
-		hart = riscv_of_processor_hartid(dn);
-		if (hart < 0)
+		rc = riscv_of_processor_hartid(dn, &hart);
+		if (rc < 0)
 			continue;
 
 		if (hart == cpuid_to_hartid_map(0)) {
@@ -90,7 +91,7 @@ void __init setup_smp(void)
 			continue;
 		}
 		if (cpuid >= NR_CPUS) {
-			pr_warn("Invalid cpuid [%d] for hartid [%d]\n",
+			pr_warn("Invalid cpuid [%d] for hartid [%lu]\n",
 				cpuid, hart);
 			continue;
 		}

drivers/clocksource/timer-riscv.c

@@ -101,20 +101,21 @@ static irqreturn_t riscv_timer_interrupt(int irq, void *dev_id)
 
 static int __init riscv_timer_init_dt(struct device_node *n)
 {
-	int cpuid, hartid, error;
+	int cpuid, error;
+	unsigned long hartid;
 	struct device_node *child;
 	struct irq_domain *domain;
 
-	hartid = riscv_of_processor_hartid(n);
-	if (hartid < 0) {
-		pr_warn("Not valid hartid for node [%pOF] error = [%d]\n",
+	error = riscv_of_processor_hartid(n, &hartid);
+	if (error < 0) {
+		pr_warn("Not valid hartid for node [%pOF] error = [%lu]\n",
 			n, hartid);
-		return hartid;
+		return error;
 	}
 
 	cpuid = riscv_hartid_to_cpuid(hartid);
 	if (cpuid < 0) {
-		pr_warn("Invalid cpuid for hartid [%d]\n", hartid);
+		pr_warn("Invalid cpuid for hartid [%lu]\n", hartid);
 		return cpuid;
 	}
 
@@ -140,7 +141,7 @@ static int __init riscv_timer_init_dt(struct device_node *n)
 		return -ENODEV;
 	}
 
-	pr_info("%s: Registering clocksource cpuid [%d] hartid [%d]\n",
+	pr_info("%s: Registering clocksource cpuid [%d] hartid [%lu]\n",
 	       __func__, cpuid, hartid);
 	error = clocksource_register_hz(&riscv_clocksource, riscv_timebase);
 	if (error) {

drivers/irqchip/irq-riscv-intc.c

@@ -95,10 +95,11 @@ static const struct irq_domain_ops riscv_intc_domain_ops = {
 static int __init riscv_intc_init(struct device_node *node,
 				  struct device_node *parent)
 {
-	int rc, hartid;
+	int rc;
+	unsigned long hartid;
 
-	hartid = riscv_of_parent_hartid(node);
-	if (hartid < 0) {
+	rc = riscv_of_parent_hartid(node, &hartid);
+	if (rc < 0) {
 		pr_warn("unable to find hart id for %pOF\n", node);
 		return 0;
 	}

drivers/irqchip/irq-sifive-plic.c

@@ -317,7 +317,8 @@ static int __init plic_init(struct device_node *node,
 	for (i = 0; i < nr_contexts; i++) {
 		struct of_phandle_args parent;
 		irq_hw_number_t hwirq;
-		int cpu, hartid;
+		int cpu;
+		unsigned long hartid;
 
 		if (of_irq_parse_one(node, i, &parent)) {
 			pr_err("failed to parse parent for context %d.\n", i);
@@ -341,8 +342,8 @@ static int __init plic_init(struct device_node *node,
 			continue;
 		}
 
-		hartid = riscv_of_parent_hartid(parent.np);
-		if (hartid < 0) {
+		error = riscv_of_parent_hartid(parent.np, &hartid);
+		if (error < 0) {
 			pr_warn("failed to parse hart ID for context %d.\n", i);
 			continue;
 		}