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Commit 0e17b560 authored by John Keller's avatar John Keller Committed by Tony Luck
Browse files

[IA64] - Altix: hotplug after intr redirect can crash system 



When redirecting a device interrupt on SN, not all links
between platform specific structures are being updated.
This can result in a system crash if an interrupt
redirection is followed by an unplug of that device.

The complete fix also requires a prom update. Though,
this patch is backward compatable and not dependent on
the prom patch.

Signed-off-by: default avatarJohn Keller <jpk@sgi.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent bb8416bf

arch/ia64/sn/kernel/irq.c

+43 −15
Original line number Diff line number Diff line
@@ -59,6 +59,22 @@ void sn_intr_free(nasid_t local_nasid, int local_widget, 
			(u64) sn_irq_info->irq_cookie, 0, 0);

}



u64 sn_intr_redirect(nasid_t local_nasid, int local_widget,

		      struct sn_irq_info *sn_irq_info,

		      nasid_t req_nasid, int req_slice)

{

	struct ia64_sal_retval ret_stuff;

	ret_stuff.status = 0;

	ret_stuff.v0 = 0;



	SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_INTERRUPT,

			(u64) SAL_INTR_REDIRECT, (u64) local_nasid,

			(u64) local_widget, __pa(sn_irq_info),

			(u64) req_nasid, (u64) req_slice, 0);



	return ret_stuff.status;

}



static unsigned int sn_startup_irq(unsigned int irq)

{

	return 0;
@@ -127,15 +143,8 @@ struct sn_irq_info *sn_retarget_vector(struct sn_irq_info *sn_irq_info, 
	struct sn_irq_info *new_irq_info;

	struct sn_pcibus_provider *pci_provider;



	new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);

	if (new_irq_info == NULL)

		return NULL;



	memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));



	bridge = (u64) new_irq_info->irq_bridge;

	bridge = (u64) sn_irq_info->irq_bridge;

	if (!bridge) {

		kfree(new_irq_info);

		return NULL; /* irq is not a device interrupt */

	}
@@ -145,8 +154,25 @@ struct sn_irq_info *sn_retarget_vector(struct sn_irq_info *sn_irq_info, 
		local_widget = TIO_SWIN_WIDGETNUM(bridge);

	else

		local_widget = SWIN_WIDGETNUM(bridge);



	vector = sn_irq_info->irq_irq;



	/* Make use of SAL_INTR_REDIRECT if PROM supports it */

	status = sn_intr_redirect(local_nasid, local_widget, sn_irq_info, nasid, slice);

	if (!status) {

		new_irq_info = sn_irq_info;

		goto finish_up;

	}



	/*

	 * PROM does not support SAL_INTR_REDIRECT, or it failed.

	 * Revert to old method.

	 */

	new_irq_info = kmalloc(sizeof(struct sn_irq_info), GFP_ATOMIC);

	if (new_irq_info == NULL)

		return NULL;



	memcpy(new_irq_info, sn_irq_info, sizeof(struct sn_irq_info));



	/* Free the old PROM new_irq_info structure */

	sn_intr_free(local_nasid, local_widget, new_irq_info);

	unregister_intr_pda(new_irq_info);
@@ -162,11 +188,18 @@ struct sn_irq_info *sn_retarget_vector(struct sn_irq_info *sn_irq_info, 
		return NULL;

	}



	register_intr_pda(new_irq_info);

	spin_lock(&sn_irq_info_lock);

	list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);

	spin_unlock(&sn_irq_info_lock);

	call_rcu(&sn_irq_info->rcu, sn_irq_info_free);





finish_up:

	/* Update kernels new_irq_info with new target info */

	cpuid = nasid_slice_to_cpuid(new_irq_info->irq_nasid,

				     new_irq_info->irq_slice);

	new_irq_info->irq_cpuid = cpuid;

	register_intr_pda(new_irq_info);



	pci_provider = sn_pci_provider[new_irq_info->irq_bridge_type];
@@ -178,11 +211,6 @@ struct sn_irq_info *sn_retarget_vector(struct sn_irq_info *sn_irq_info, 
	    pci_provider && pci_provider->target_interrupt)

		(pci_provider->target_interrupt)(new_irq_info);



	spin_lock(&sn_irq_info_lock);

	list_replace_rcu(&sn_irq_info->list, &new_irq_info->list);

	spin_unlock(&sn_irq_info_lock);

	call_rcu(&sn_irq_info->rcu, sn_irq_info_free);



#ifdef CONFIG_SMP

	cpuphys = cpu_physical_id(cpuid);

	set_irq_affinity_info((vector & 0xff), cpuphys, 0);

include/asm-ia64/sn/sn_sal.h

+1 −0
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ 
/* interrupt handling */

#define SAL_INTR_ALLOC		1

#define SAL_INTR_FREE		2

#define SAL_INTR_REDIRECT	3



/*

 * operations available on the generic SN_SAL_SYSCTL_OP