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

[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
......@@ -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);
......
......@@ -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
......
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