Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b6db63d1 authored by Gautham R Shenoy's avatar Gautham R Shenoy Committed by Benjamin Herrenschmidt
Browse files

pseries/pseries: Add code to online/offline CPUs of a DLPAR node 



Currently the cpu-allocation/deallocation on pSeries is a
two step process from the Userspace.

- Set the indicators and update the device tree by writing to the sysfs
  tunable "probe" during allocation and "release" during deallocation.
- Online / Offline the CPUs of the allocated/would_be_deallocated node by
  writing to the sysfs tunable "online".

This patch adds kernel code to online/offline the CPUs soon_after/just_before
they have been allocated/would_be_deallocated. This way, the userspace tool
that performs DLPAR operations would only have to deal with one set of sysfs
tunables namely "probe" and release".

Signed-off-by: default avatarGautham R Shenoy <ego@in.ibm.com>
Signed-off-by: default avatarNathan Fontenot <nfont@austin.ibm.com>
Acked-by: default avatarVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 8389b37d

arch/powerpc/platforms/pseries/dlpar.c

+101 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/proc_fs.h>

#include <linux/spinlock.h>

#include <linux/cpu.h>

#include "offline_states.h"



#include <asm/prom.h>

#include <asm/machdep.h>
@@ -287,6 +288,98 @@ int dlpar_detach_node(struct device_node *dn) 
	return 0;

}



int online_node_cpus(struct device_node *dn)

{

	int rc = 0;

	unsigned int cpu;

	int len, nthreads, i;

	const u32 *intserv;



	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);

	if (!intserv)

		return -EINVAL;



	nthreads = len / sizeof(u32);



	cpu_maps_update_begin();

	for (i = 0; i < nthreads; i++) {

		for_each_present_cpu(cpu) {

			if (get_hard_smp_processor_id(cpu) != intserv[i])

				continue;

			BUG_ON(get_cpu_current_state(cpu)

					!= CPU_STATE_OFFLINE);

			cpu_maps_update_done();

			rc = cpu_up(cpu);

			if (rc)

				goto out;

			cpu_maps_update_begin();



			break;

		}

		if (cpu == num_possible_cpus())

			printk(KERN_WARNING "Could not find cpu to online "

			       "with physical id 0x%x\n", intserv[i]);

	}

	cpu_maps_update_done();



out:

	return rc;



}



int offline_node_cpus(struct device_node *dn)

{

	int rc = 0;

	unsigned int cpu;

	int len, nthreads, i;

	const u32 *intserv;



	intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);

	if (!intserv)

		return -EINVAL;



	nthreads = len / sizeof(u32);



	cpu_maps_update_begin();

	for (i = 0; i < nthreads; i++) {

		for_each_present_cpu(cpu) {

			if (get_hard_smp_processor_id(cpu) != intserv[i])

				continue;



			if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)

				break;



			if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {

				cpu_maps_update_done();

				rc = cpu_down(cpu);

				if (rc)

					goto out;

				cpu_maps_update_begin();

				break;



			}



			/*

			 * The cpu is in CPU_STATE_INACTIVE.

			 * Upgrade it's state to CPU_STATE_OFFLINE.

			 */

			set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);

			BUG_ON(plpar_hcall_norets(H_PROD, intserv[i])

								!= H_SUCCESS);

			__cpu_die(cpu);

			break;

		}

		if (cpu == num_possible_cpus())

			printk(KERN_WARNING "Could not find cpu to offline "

			       "with physical id 0x%x\n", intserv[i]);

	}

	cpu_maps_update_done();



out:

	return rc;



}



#define DR_ENTITY_SENSE		9003

#define DR_ENTITY_PRESENT	1

#define DR_ENTITY_UNUSABLE	2
@@ -385,6 +478,8 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count) 
		dlpar_free_cc_nodes(dn);

	}



	rc = online_node_cpus(dn);



	return rc ? rc : count;

}
@@ -404,6 +499,12 @@ static ssize_t dlpar_cpu_release(const char *buf, size_t count) 
		return -EINVAL;

	}



	rc = offline_node_cpus(dn);

	if (rc) {

		of_node_put(dn);

		return -EINVAL;

	}



	rc = dlpar_release_drc(*drc_index);

	if (rc) {

		of_node_put(dn);