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: John Keller <jpk@xxxxxxx>
---
arch/ia64/sn/kernel/irq.c | 58 ++++++++++++++++++++++++---------
include/asm-ia64/sn/sn_sal.h | 1
2 files changed, 44 insertions(+), 15 deletions(-)
Index: linux-2.6/arch/ia64/sn/kernel/irq.c
===================================================================
--- linux-2.6.orig/arch/ia64/sn/kernel/irq.c 2007-05-01 15:01:26.472284737 -0500
+++ linux-2.6/arch/ia64/sn/kernel/irq.c 2007-05-02 09:04:31.370355274 -0500
@@ -59,6 +59,22 @@ void sn_intr_free(nasid_t local_nasid, i
(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(s
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(s
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(s
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(s
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);
Index: linux-2.6/include/asm-ia64/sn/sn_sal.h
===================================================================
--- linux-2.6.orig/include/asm-ia64/sn/sn_sal.h 2007-05-01 15:01:26.472284737 -0500
+++ linux-2.6/include/asm-ia64/sn/sn_sal.h 2007-05-01 15:01:28.564529663 -0500
@@ -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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