parisc: Switch from GENERIC_CPU_DEVICES to GENERIC_ARCH_TOPOLOGY

Switch away from the own cpu topology code to common code which is used
by ARM64 and RISCV. That will allow us to enable CPU hotplug later on.
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/Kconfig

@@ -37,7 +37,7 @@ config PARISC
 	select GENERIC_PCI_IOMAP
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_SMP_IDLE_THREAD
-	select GENERIC_CPU_DEVICES
+	select GENERIC_ARCH_TOPOLOGY if SMP
 	select GENERIC_LIB_DEVMEM_IS_ALLOWED
 	select SYSCTL_ARCH_UNALIGN_ALLOW
 	select SYSCTL_EXCEPTION_TRACE
@@ -279,16 +279,9 @@ config SMP
 
 	  If you don't know what to do here, say N.
 
-config PARISC_CPU_TOPOLOGY
-	bool "Support cpu topology definition"
-	depends on SMP
-	default y
-	help
-	  Support PARISC cpu topology definition.
-
 config SCHED_MC
 	bool "Multi-core scheduler support"
-	depends on PARISC_CPU_TOPOLOGY && PA8X00
+	depends on GENERIC_ARCH_TOPOLOGY && PA8X00
 	help
 	  Multi-core scheduler support improves the CPU scheduler's decision
 	  making when dealing with multi-core CPU chips at a cost of slightly

arch/parisc/include/asm/topology.h

 #ifndef _ASM_PARISC_TOPOLOGY_H
 #define _ASM_PARISC_TOPOLOGY_H
 
-#ifdef CONFIG_PARISC_CPU_TOPOLOGY
+#ifdef CONFIG_GENERIC_ARCH_TOPOLOGY
 
 #include <linux/cpumask.h>
-
-struct cputopo_parisc {
-	int thread_id;
-	int core_id;
-	int socket_id;
-	cpumask_t thread_sibling;
-	cpumask_t core_sibling;
-};
-
-extern struct cputopo_parisc cpu_topology[NR_CPUS];
-
-#define topology_physical_package_id(cpu)	(cpu_topology[cpu].socket_id)
-#define topology_core_id(cpu)		(cpu_topology[cpu].core_id)
-#define topology_core_cpumask(cpu)	(&cpu_topology[cpu].core_sibling)
-#define topology_sibling_cpumask(cpu)	(&cpu_topology[cpu].thread_sibling)
-
-void init_cpu_topology(void);
-void store_cpu_topology(unsigned int cpuid);
-const struct cpumask *cpu_coregroup_mask(int cpu);
+#include <linux/arch_topology.h>
 
 #else
 
 static inline void init_cpu_topology(void) { }
 static inline void store_cpu_topology(unsigned int cpuid) { }
+static inline void reset_cpu_topology(void) { }
 
 #endif
 

arch/parisc/kernel/Makefile

@@ -31,7 +31,7 @@ obj-$(CONFIG_AUDIT)	+= audit.o
 obj64-$(CONFIG_AUDIT)	+= compat_audit.o
 # only supported for PCX-W/U in 64-bit mode at the moment
 obj-$(CONFIG_64BIT)	+= perf.o perf_asm.o $(obj64-y)
-obj-$(CONFIG_PARISC_CPU_TOPOLOGY)	+= topology.o
+obj-$(CONFIG_GENERIC_ARCH_TOPOLOGY)	+= topology.o
 obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
 obj-$(CONFIG_JUMP_LABEL)		+= jump_label.o

arch/parisc/kernel/processor.c

@@ -19,6 +19,7 @@
 #include <linux/random.h>
 #include <linux/slab.h>
 #include <linux/cpu.h>
+#include <asm/topology.h>
 #include <asm/param.h>
 #include <asm/cache.h>
 #include <asm/hardware.h>	/* for register_parisc_driver() stuff */
@@ -390,7 +391,7 @@ show_cpuinfo (struct seq_file *m, void *v)
 				 boot_cpu_data.cpu_hz / 1000000,
 				 boot_cpu_data.cpu_hz % 1000000  );
 
-#ifdef CONFIG_PARISC_CPU_TOPOLOGY
+#ifdef CONFIG_GENERIC_ARCH_TOPOLOGY
 		seq_printf(m, "physical id\t: %d\n",
 				topology_physical_package_id(cpu));
 		seq_printf(m, "siblings\t: %d\n",
@@ -460,5 +461,6 @@ static struct parisc_driver cpu_driver __refdata = {
  */
 void __init processor_init(void)
 {
+	reset_cpu_topology();
 	register_parisc_driver(&cpu_driver);
 }

arch/parisc/kernel/topology.c

@@ -13,45 +13,11 @@
 #include <linux/percpu.h>
 #include <linux/sched.h>
 #include <linux/sched/topology.h>
+#include <linux/cpu.h>
 
 #include <asm/topology.h>
 
- /*
-  * cpu topology table
-  */
-struct cputopo_parisc cpu_topology[NR_CPUS] __read_mostly;
-EXPORT_SYMBOL_GPL(cpu_topology);
-
-const struct cpumask *cpu_coregroup_mask(int cpu)
-{
-	return &cpu_topology[cpu].core_sibling;
-}
-
-static void update_siblings_masks(unsigned int cpuid)
-{
-	struct cputopo_parisc *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
-	int cpu;
-
-	/* update core and thread sibling masks */
-	for_each_possible_cpu(cpu) {
-		cpu_topo = &cpu_topology[cpu];
-
-		if (cpuid_topo->socket_id != cpu_topo->socket_id)
-			continue;
-
-		cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
-		if (cpu != cpuid)
-			cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
-
-		if (cpuid_topo->core_id != cpu_topo->core_id)
-			continue;
-
-		cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
-		if (cpu != cpuid)
-			cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
-	}
-	smp_wmb();
-}
+static DEFINE_PER_CPU(struct cpu, cpu_devices);
 
 static int dualcores_found __initdata;
 
@@ -62,7 +28,7 @@ static int dualcores_found __initdata;
  */
 void __init store_cpu_topology(unsigned int cpuid)
 {
-	struct cputopo_parisc *cpuid_topo = &cpu_topology[cpuid];
+	struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
 	struct cpuinfo_parisc *p;
 	int max_socket = -1;
 	unsigned long cpu;
@@ -71,6 +37,12 @@ void __init store_cpu_topology(unsigned int cpuid)
 	if (cpuid_topo->core_id != -1)
 		return;
 
+#ifdef CONFIG_HOTPLUG_CPU
+	per_cpu(cpu_devices, cpuid).hotpluggable = 1;
+#endif
+	if (register_cpu(&per_cpu(cpu_devices, cpuid), cpuid))
+		pr_warn("Failed to register CPU%d device", cpuid);
+
 	/* create cpu topology mapping */
 	cpuid_topo->thread_id = -1;
 	cpuid_topo->core_id = 0;
@@ -86,25 +58,25 @@ void __init store_cpu_topology(unsigned int cpuid)
 			cpuid_topo->core_id = cpu_topology[cpu].core_id;
 			if (p->cpu_loc) {
 				cpuid_topo->core_id++;
-				cpuid_topo->socket_id = cpu_topology[cpu].socket_id;
+				cpuid_topo->package_id = cpu_topology[cpu].package_id;
 				dualcores_found = 1;
 				continue;
 			}
 		}
 
-		if (cpuid_topo->socket_id == -1)
-			max_socket = max(max_socket, cpu_topology[cpu].socket_id);
+		if (cpuid_topo->package_id == -1)
+			max_socket = max(max_socket, cpu_topology[cpu].package_id);
 	}
 
-	if (cpuid_topo->socket_id == -1)
-		cpuid_topo->socket_id = max_socket + 1;
+	if (cpuid_topo->package_id == -1)
+		cpuid_topo->package_id = max_socket + 1;
 
 	update_siblings_masks(cpuid);
 
 	pr_info("CPU%u: cpu core %d of socket %d\n",
 		cpuid,
 		cpu_topology[cpuid].core_id,
-		cpu_topology[cpuid].socket_id);
+		cpu_topology[cpuid].package_id);
 }
 
 static struct sched_domain_topology_level parisc_mc_topology[] = {
@@ -122,20 +94,6 @@ static struct sched_domain_topology_level parisc_mc_topology[] = {
  */
 void __init init_cpu_topology(void)
 {
-	unsigned int cpu;
-
-	/* init core mask and capacity */
-	for_each_possible_cpu(cpu) {
-		struct cputopo_parisc *cpu_topo = &(cpu_topology[cpu]);
-
-		cpu_topo->thread_id = -1;
-		cpu_topo->core_id =  -1;
-		cpu_topo->socket_id = -1;
-		cpumask_clear(&cpu_topo->core_sibling);
-		cpumask_clear(&cpu_topo->thread_sibling);
-	}
-	smp_wmb();
-
 	/* Set scheduler topology descriptor */
 	if (dualcores_found)
 		set_sched_topology(parisc_mc_topology);