[IA64] hotplug/ia64: SN Hotplug Driver: SN IRQ Fixes

This patch  fixes the SN IRQ code such that cpu affinity and
Hotplug can modify IRQ values.  The sn_irq_info structures are now locked
using a RCU lock mechanism to avoid lock contention in the lost interrupt
WAR code.

Signed-off-by: Prarit Bhargava <prarit@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/include/asm-ia64/sn/intr.h b/include/asm-ia64/sn/intr.h
index e51471fb0867..e190dd4213d5 100644
--- a/include/asm-ia64/sn/intr.h
+++ b/include/asm-ia64/sn/intr.h
@@ -9,6 +9,8 @@
 #ifndef _ASM_IA64_SN_INTR_H
 #define _ASM_IA64_SN_INTR_H
 
+#include <linux/rcupdate.h>
+
 #define SGI_UART_VECTOR         (0xe9)
 #define SGI_PCIBR_ERROR         (0x33)
 
@@ -33,7 +35,7 @@
 
 // The SN PROM irq struct
 struct sn_irq_info {
-        struct sn_irq_info *irq_next;   /* sharing irq list          */
+        struct sn_irq_info *irq_next;   /* deprecated DO NOT USE     */
         short           irq_nasid;      /* Nasid IRQ is assigned to  */
         int             irq_slice;      /* slice IRQ is assigned to  */
         int             irq_cpuid;      /* kernel logical cpuid      */
@@ -47,6 +49,8 @@ struct sn_irq_info {
         int             irq_cookie;     /* unique cookie             */
         int             irq_flags;      /* flags */
         int             irq_share_cnt;  /* num devices sharing IRQ   */
+        struct list_head        list;   /* list of sn_irq_info structs */
+        struct rcu_head         rcu;    /* rcu callback list */
 };
 
 extern void sn_send_IPI_phys(int, long, int, int);