Commit d7a0dab8 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'core-smp-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull core SMP updates from Ingo Molnar:
 "Two main change is generic vCPU pinning and physical CPU SMP-call
  support, for Xen to be able to perform certain calls on specific
  physical CPUs - by Juergen Gross"

* 'core-smp-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Allocate smp_call_on_cpu() workqueue on stack too
  hwmon: Use smp_call_on_cpu() for dell-smm i8k
  dcdbas: Make use of smp_call_on_cpu()
  xen: Add xen_pin_vcpu() to support calling functions on a dedicated pCPU
  smp: Add function to execute a function synchronously on a CPU
  virt, sched: Add generic vCPU pinning support
  xen: Sync xen header
parents 4b978934 8db54949

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -8860,6 +8860,7 @@ S: Supported 
F:	Documentation/virtual/paravirt_ops.txt

F:	arch/*/kernel/paravirt*

F:	arch/*/include/asm/paravirt.h

F:	include/linux/hypervisor.h



PARIDE DRIVERS FOR PARALLEL PORT IDE DEVICES

M:	Tim Waugh <tim@cyberelk.net>

arch/x86/include/asm/hypervisor.h

+4 −0
Original line number Diff line number Diff line
@@ -43,6 +43,9 @@ struct hypervisor_x86 { 


	/* X2APIC detection (run once per boot) */

	bool		(*x2apic_available)(void);



	/* pin current vcpu to specified physical cpu (run rarely) */

	void		(*pin_vcpu)(int);

};



extern const struct hypervisor_x86 *x86_hyper;
@@ -56,6 +59,7 @@ extern const struct hypervisor_x86 x86_hyper_kvm; 
extern void init_hypervisor(struct cpuinfo_x86 *c);

extern void init_hypervisor_platform(void);

extern bool hypervisor_x2apic_available(void);

extern void hypervisor_pin_vcpu(int cpu);

#else

static inline void init_hypervisor(struct cpuinfo_x86 *c) { }

static inline void init_hypervisor_platform(void) { }

arch/x86/kernel/cpu/hypervisor.c

+11 −0
Original line number Diff line number Diff line
@@ -86,3 +86,14 @@ bool __init hypervisor_x2apic_available(void) 
	       x86_hyper->x2apic_available &&

	       x86_hyper->x2apic_available();

}



void hypervisor_pin_vcpu(int cpu)

{

	if (!x86_hyper)

		return;



	if (x86_hyper->pin_vcpu)

		x86_hyper->pin_vcpu(cpu);

	else

		WARN_ONCE(1, "vcpu pinning requested but not supported!\n");

}

arch/x86/xen/enlighten.c

+40 −0
Original line number Diff line number Diff line
@@ -1925,6 +1925,45 @@ static void xen_set_cpu_features(struct cpuinfo_x86 *c) 
	}

}



static void xen_pin_vcpu(int cpu)

{

	static bool disable_pinning;

	struct sched_pin_override pin_override;

	int ret;



	if (disable_pinning)

		return;



	pin_override.pcpu = cpu;

	ret = HYPERVISOR_sched_op(SCHEDOP_pin_override, &pin_override);



	/* Ignore errors when removing override. */

	if (cpu < 0)

		return;



	switch (ret) {

	case -ENOSYS:

		pr_warn("Unable to pin on physical cpu %d. In case of problems consider vcpu pinning.\n",

			cpu);

		disable_pinning = true;

		break;

	case -EPERM:

		WARN(1, "Trying to pin vcpu without having privilege to do so\n");

		disable_pinning = true;

		break;

	case -EINVAL:

	case -EBUSY:

		pr_warn("Physical cpu %d not available for pinning. Check Xen cpu configuration.\n",

			cpu);

		break;

	case 0:

		break;

	default:

		WARN(1, "rc %d while trying to pin vcpu\n", ret);

		disable_pinning = true;

	}

}



const struct hypervisor_x86 x86_hyper_xen = {

	.name			= "Xen",

	.detect			= xen_platform,
@@ -1933,6 +1972,7 @@ const struct hypervisor_x86 x86_hyper_xen = { 
#endif

	.x2apic_available	= xen_x2apic_para_available,

	.set_cpu_features       = xen_set_cpu_features,

	.pin_vcpu               = xen_pin_vcpu,

};

EXPORT_SYMBOL(x86_hyper_xen);

drivers/firmware/dcdbas.c

+26 −25
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/platform_device.h>

#include <linux/dma-mapping.h>

#include <linux/errno.h>

#include <linux/cpu.h>

#include <linux/gfp.h>

#include <linux/init.h>

#include <linux/kernel.h>
@@ -238,33 +239,14 @@ static ssize_t host_control_on_shutdown_store(struct device *dev, 
	return count;

}



/**

 * dcdbas_smi_request: generate SMI request

 *

 * Called with smi_data_lock.

 */

int dcdbas_smi_request(struct smi_cmd *smi_cmd)

static int raise_smi(void *par)

{

	cpumask_var_t old_mask;

	int ret = 0;



	if (smi_cmd->magic != SMI_CMD_MAGIC) {

		dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",

			 __func__);

		return -EBADR;

	}

	struct smi_cmd *smi_cmd = par;



	/* SMI requires CPU 0 */

	if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))

		return -ENOMEM;



	cpumask_copy(old_mask, &current->cpus_allowed);

	set_cpus_allowed_ptr(current, cpumask_of(0));

	if (smp_processor_id() != 0) {

		dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",

			__func__);

		ret = -EBUSY;

		goto out;

		return -EBUSY;

	}



	/* generate SMI */
@@ -280,9 +262,28 @@ int dcdbas_smi_request(struct smi_cmd *smi_cmd) 
		: "memory"

	);



out:

	set_cpus_allowed_ptr(current, old_mask);

	free_cpumask_var(old_mask);

	return 0;

}

/**

 * dcdbas_smi_request: generate SMI request

 *

 * Called with smi_data_lock.

 */

int dcdbas_smi_request(struct smi_cmd *smi_cmd)

{

	int ret;



	if (smi_cmd->magic != SMI_CMD_MAGIC) {

		dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",

			 __func__);

		return -EBADR;

	}



	/* SMI requires CPU 0 */

	get_online_cpus();

	ret = smp_call_on_cpu(0, raise_smi, smi_cmd, true);

	put_online_cpus();



	return ret;

}

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