[PATCH V2 13/21] RISC-V: cpu: Enable cpuinfo for ACPI systems

[Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>]

On ACPI based platforms, few details like ISA need to be read
from the ACPI table. Enable cpuinfo on ACPI based systems.

Signed-off-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
 arch/riscv/kernel/cpu.c | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index 1b9a5a66e55a..a227c0661b19 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -3,10 +3,12 @@
  * Copyright (C) 2012 Regents of the University of California
  */
 
+#include <linux/acpi.h>
 #include <linux/cpu.h>
 #include <linux/init.h>
 #include <linux/seq_file.h>
 #include <linux/of.h>
+#include <asm/acpi.h>
 #include <asm/csr.h>
 #include <asm/hwcap.h>
 #include <asm/sbi.h>
@@ -256,26 +258,41 @@ static void c_stop(struct seq_file *m, void *v)
 {
 }
 
+static void acpi_print_hart_info(struct seq_file *m, unsigned long cpu)
+{
+	const char *isa;
+
+	if (!acpi_get_riscv_isa(NULL, get_acpi_id_for_cpu(cpu), &isa))
+		print_isa(m, isa);
+}
+
 static int c_show(struct seq_file *m, void *v)
 {
 	unsigned long cpu_id = (unsigned long)v - 1;
-	struct device_node *node = of_get_cpu_node(cpu_id, NULL);
 	struct riscv_cpuinfo *ci = per_cpu_ptr(&riscv_cpuinfo, cpu_id);
+	struct device_node *node;
 	const char *compat, *isa;
 
 	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 (acpi_disabled) {
+		node = of_get_cpu_node(cpu_id, NULL);
+		if (!of_property_read_string(node, "riscv,isa", &isa))
+			print_isa(m, isa);
+		if (!of_property_read_string(node, "compatible", &compat) &&
+		    strcmp(compat, "riscv"))
+			seq_printf(m, "uarch\t\t: %s\n", compat);
+		of_node_put(node);
+	} else {
+		acpi_print_hart_info(m, cpu_id);
+	}
+
 	print_mmu(m);
-	if (!of_property_read_string(node, "compatible", &compat)
-	    && strcmp(compat, "riscv"))
-		seq_printf(m, "uarch\t\t: %s\n", compat);
 	seq_printf(m, "mvendorid\t: 0x%lx\n", ci->mvendorid);
 	seq_printf(m, "marchid\t\t: 0x%lx\n", ci->marchid);
 	seq_printf(m, "mimpid\t\t: 0x%lx\n", ci->mimpid);
 	seq_puts(m, "\n");
-	of_node_put(node);
 
 	return 0;
 }
-- 
2.34.1