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Commit 7fe67a11 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull leftover x86 fixes from Ingo Molnar:
 "Two leftover fixes that did not make it into v3.13"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Add check for number of available vectors before CPU down
  x86, cpu, amd: Add workaround for family 16h, erratum 793
parents fab5669d da6139e4

arch/x86/include/asm/irq.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ extern void irq_ctx_init(int cpu); 


#ifdef CONFIG_HOTPLUG_CPU

#include <linux/cpumask.h>

extern int check_irq_vectors_for_cpu_disable(void);

extern void fixup_irqs(void);

extern void irq_force_complete_move(int);

#endif

arch/x86/include/uapi/asm/msr-index.h

+1 −0
Original line number Diff line number Diff line
@@ -184,6 +184,7 @@ 
#define MSR_AMD64_PATCH_LOADER		0xc0010020

#define MSR_AMD64_OSVW_ID_LENGTH	0xc0010140

#define MSR_AMD64_OSVW_STATUS		0xc0010141

#define MSR_AMD64_LS_CFG		0xc0011020

#define MSR_AMD64_DC_CFG		0xc0011022

#define MSR_AMD64_BU_CFG2		0xc001102a

#define MSR_AMD64_IBSFETCHCTL		0xc0011030

arch/x86/kernel/cpu/amd.c

+10 −0
Original line number Diff line number Diff line
@@ -507,6 +507,16 @@ static void early_init_amd(struct cpuinfo_x86 *c) 
			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);

	}

#endif



	/* F16h erratum 793, CVE-2013-6885 */

	if (c->x86 == 0x16 && c->x86_model <= 0xf) {

		u64 val;



		rdmsrl(MSR_AMD64_LS_CFG, val);

		if (!(val & BIT(15)))

			wrmsrl(MSR_AMD64_LS_CFG, val | BIT(15));

	}



}



static const int amd_erratum_383[];

arch/x86/kernel/irq.c

+70 −0
Original line number Diff line number Diff line
@@ -266,6 +266,76 @@ __visible void smp_trace_x86_platform_ipi(struct pt_regs *regs) 
EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);



#ifdef CONFIG_HOTPLUG_CPU

/*

 * This cpu is going to be removed and its vectors migrated to the remaining

 * online cpus.  Check to see if there are enough vectors in the remaining cpus.

 * This function is protected by stop_machine().

 */

int check_irq_vectors_for_cpu_disable(void)

{

	int irq, cpu;

	unsigned int this_cpu, vector, this_count, count;

	struct irq_desc *desc;

	struct irq_data *data;

	struct cpumask affinity_new, online_new;



	this_cpu = smp_processor_id();

	cpumask_copy(&online_new, cpu_online_mask);

	cpu_clear(this_cpu, online_new);



	this_count = 0;

	for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {

		irq = __this_cpu_read(vector_irq[vector]);

		if (irq >= 0) {

			desc = irq_to_desc(irq);

			data = irq_desc_get_irq_data(desc);

			cpumask_copy(&affinity_new, data->affinity);

			cpu_clear(this_cpu, affinity_new);



			/* Do not count inactive or per-cpu irqs. */

			if (!irq_has_action(irq) || irqd_is_per_cpu(data))

				continue;



			/*

			 * A single irq may be mapped to multiple

			 * cpu's vector_irq[] (for example IOAPIC cluster

			 * mode).  In this case we have two

			 * possibilities:

			 *

			 * 1) the resulting affinity mask is empty; that is

			 * this the down'd cpu is the last cpu in the irq's

			 * affinity mask, or

			 *

			 * 2) the resulting affinity mask is no longer

			 * a subset of the online cpus but the affinity

			 * mask is not zero; that is the down'd cpu is the

			 * last online cpu in a user set affinity mask.

			 */

			if (cpumask_empty(&affinity_new) ||

			    !cpumask_subset(&affinity_new, &online_new))

				this_count++;

		}

	}



	count = 0;

	for_each_online_cpu(cpu) {

		if (cpu == this_cpu)

			continue;

		for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;

		     vector++) {

			if (per_cpu(vector_irq, cpu)[vector] < 0)

				count++;

		}

	}



	if (count < this_count) {

		pr_warn("CPU %d disable failed: CPU has %u vectors assigned and there are only %u available.\n",

			this_cpu, this_count, count);

		return -ERANGE;

	}

	return 0;

}



/* A cpu has been removed from cpu_online_mask.  Reset irq affinities. */

void fixup_irqs(void)

{

arch/x86/kernel/smpboot.c

+6 −0
Original line number Diff line number Diff line
@@ -1312,6 +1312,12 @@ void cpu_disable_common(void) 


int native_cpu_disable(void)

{

	int ret;



	ret = check_irq_vectors_for_cpu_disable();

	if (ret)

		return ret;



	clear_local_APIC();



	cpu_disable_common();