Commit d1cb9d1a authored by David Miller's avatar David Miller Committed by Grant Likely
Browse files

of: Make cpu node handling more portable. 



Use for_each_node_by_type() to iterate all cpu nodes in the
system.

Provide and overridable function arch_find_n_match_cpu_physical_id,
which sees if the given device node matches 'cpu' and if so sets
'*thread' when non-NULL to the cpu thread number within the core.

The default implementation behaves the same as the existing code.

Add a sparc64 implementation.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Tested-by: default avatarSudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: default avatarGrant Likely <grant.likely@linaro.org>
parent 444c91e5

arch/sparc/kernel/prom_64.c

+53 −0
Original line number Diff line number Diff line
@@ -373,6 +373,59 @@ static const char *get_mid_prop(void) 
	return (tlb_type == spitfire ? "upa-portid" : "portid");

}



bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,

				       int cpu, unsigned int *thread)

{

	const char *mid_prop = get_mid_prop();

	int this_cpu_id;



	/* On hypervisor based platforms we interrogate the 'reg'

	 * property.  On everything else we look for a 'upa-portis',

	 * 'portid', or 'cpuid' property.

	 */



	if (tlb_type == hypervisor) {

		struct property *prop = of_find_property(cpun, "reg", NULL);

		u32 *regs;



		if (!prop) {

			pr_warn("CPU node missing reg property\n");

			return false;

		}

		regs = prop->value;

		this_cpu_id = regs[0] & 0x0fffffff;

	} else {

		this_cpu_id = of_getintprop_default(cpun, mid_prop, -1);



		if (this_cpu_id < 0) {

			mid_prop = "cpuid";

			this_cpu_id = of_getintprop_default(cpun, mid_prop, -1);

		}

		if (this_cpu_id < 0) {

			pr_warn("CPU node missing cpu ID property\n");

			return false;

		}

	}

	if (this_cpu_id == cpu) {

		if (thread) {

			int proc_id = cpu_data(cpu).proc_id;



			/* On sparc64, the cpu thread information is obtained

			 * either from OBP or the machine description.  We've

			 * actually probed this information already long before

			 * this interface gets called so instead of interrogating

			 * both the OF node and the MDESC again, just use what

			 * we discovered already.

			 */

			if (proc_id < 0)

				proc_id = 0;

			*thread = proc_id;

		}

		return true;

	}

	return false;

}



static void *of_iterate_over_cpus(void *(*func)(struct device_node *, int, int), int arg)

{

	struct device_node *dp;

drivers/of/base.c

+28 −17
Original line number Diff line number Diff line
@@ -280,6 +280,31 @@ static bool __of_find_n_match_cpu_property(struct device_node *cpun, 
	return false;

}



/*

 * arch_find_n_match_cpu_physical_id - See if the given device node is

 * for the cpu corresponding to logical cpu 'cpu'.  Return true if so,

 * else false.  If 'thread' is non-NULL, the local thread number within the

 * core is returned in it.

 */

bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,

					      int cpu, unsigned int *thread)

{

	/* Check for non-standard "ibm,ppc-interrupt-server#s" property

	 * for thread ids on PowerPC. If it doesn't exist fallback to

	 * standard "reg" property.

	 */

	if (IS_ENABLED(CONFIG_PPC) &&

	    __of_find_n_match_cpu_property(cpun,

					   "ibm,ppc-interrupt-server#s",

					   cpu, thread))

		return true;



	if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))

		return true;



	return false;

}



/**

 * of_get_cpu_node - Get device node associated with the given logical CPU

 *
@@ -300,24 +325,10 @@ static bool __of_find_n_match_cpu_property(struct device_node *cpun, 
 */

struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)

{

	struct device_node *cpun, *cpus;

	struct device_node *cpun;



	cpus = of_find_node_by_path("/cpus");

	if (!cpus)

		return NULL;



	for_each_child_of_node(cpus, cpun) {

		if (of_node_cmp(cpun->type, "cpu"))

			continue;

		/* Check for non-standard "ibm,ppc-interrupt-server#s" property

		 * for thread ids on PowerPC. If it doesn't exist fallback to

		 * standard "reg" property.

		 */

		if (IS_ENABLED(CONFIG_PPC) &&

			__of_find_n_match_cpu_property(cpun,

				"ibm,ppc-interrupt-server#s", cpu, thread))

			return cpun;

		if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))

	for_each_node_by_type(cpun, "cpu") {

		if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))

			return cpun;

	}

	return NULL;

include/linux/cpu.h

+3 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/cpumask.h>



struct device;

struct device_node;



struct cpu {

	int node_id;		/* The node which contains the CPU */
@@ -29,6 +30,8 @@ extern int register_cpu(struct cpu *cpu, int num); 
extern struct device *get_cpu_device(unsigned cpu);

extern bool cpu_is_hotpluggable(unsigned cpu);

extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);

extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,

					      int cpu, unsigned int *thread);



extern int cpu_add_dev_attr(struct device_attribute *attr);

extern void cpu_remove_dev_attr(struct device_attribute *attr);

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