3 files changed, 50 insertions, 22 deletions

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 53243ca7816d..c86591b906fa 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3228,12 +3228,9 @@ unsigned int create_irq_nr(unsigned int irq_want, int node)
         }
         spin_unlock_irqrestore(&vector_lock, flags);
 
-        if (irq > 0) {
-                dynamic_irq_init(irq);
-                /* restore it, in case dynamic_irq_init clear it */
-                if (desc_new)
-                        desc_new->chip_data = cfg_new;
-        }
+        if (irq > 0)
+                dynamic_irq_init_keep_chip_data(irq);
+
         return irq;
 }
 
@@ -3256,17 +3253,12 @@ void destroy_irq(unsigned int irq)
 {
         unsigned long flags;
         struct irq_cfg *cfg;
-        struct irq_desc *desc;
 
-        /* store it, in case dynamic_irq_cleanup clear it */
-        desc = irq_to_desc(irq);
-        cfg = desc->chip_data;
-        dynamic_irq_cleanup(irq);
-        /* connect back irq_cfg */
-        desc->chip_data = cfg;
+        dynamic_irq_cleanup_keep_chip_data(irq);
 
         free_irte(irq);
         spin_lock_irqsave(&vector_lock, flags);
+        cfg = irq_to_desc(irq)->chip_data;
         __clear_irq_vector(irq, cfg);
         spin_unlock_irqrestore(&vector_lock, flags);
 }
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 451481c082b5..4d9b26e044bc 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -400,7 +400,9 @@ static inline int irq_has_action(unsigned int irq)
 
 /* Dynamic irq helper functions */
 extern void dynamic_irq_init(unsigned int irq);
+void dynamic_irq_init_keep_chip_data(unsigned int irq);
 extern void dynamic_irq_cleanup(unsigned int irq);
+void dynamic_irq_cleanup_keep_chip_data(unsigned int irq);
 
 /* Set/get chip/data for an IRQ: */
 extern int set_irq_chip(unsigned int irq, struct irq_chip *chip);
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index ecc3fa28f666..d70394f12ee9 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -18,11 +18,7 @@
 
 #include "internals.h"
 
-/**
- *      dynamic_irq_init - initialize a dynamically allocated irq
- *      @irq:   irq number to initialize
- */
-void dynamic_irq_init(unsigned int irq)
+static void dynamic_irq_init_x(unsigned int irq, bool keep_chip_data)
 {
         struct irq_desc *desc;
         unsigned long flags;
@@ -41,7 +37,8 @@ void dynamic_irq_init(unsigned int irq)
         desc->depth = 1;
         desc->msi_desc = NULL;
         desc->handler_data = NULL;
-        desc->chip_data = NULL;
+        if (!keep_chip_data)
+                desc->chip_data = NULL;
         desc->action = NULL;
         desc->irq_count = 0;
         desc->irqs_unhandled = 0;
@@ -55,10 +52,26 @@ void dynamic_irq_init(unsigned int irq)
 }
 
 /**
- *      dynamic_irq_cleanup - cleanup a dynamically allocated irq
+ *      dynamic_irq_init - initialize a dynamically allocated irq
  *      @irq:   irq number to initialize
  */
-void dynamic_irq_cleanup(unsigned int irq)
+void dynamic_irq_init(unsigned int irq)
+{
+        dynamic_irq_init_x(irq, false);
+}
+
+/**
+ *      dynamic_irq_init_keep_chip_data - initialize a dynamically allocated irq
+ *      @irq:   irq number to initialize
+ *
+ *      does not set irq_to_desc(irq)->chip_data to NULL
+ */
+void dynamic_irq_init_keep_chip_data(unsigned int irq)
+{
+        dynamic_irq_init_x(irq, true);
+}
+
+static void dynamic_irq_cleanup_x(unsigned int irq, bool keep_chip_data)
 {
         struct irq_desc *desc = irq_to_desc(irq);
         unsigned long flags;
@@ -77,7 +90,8 @@ void dynamic_irq_cleanup(unsigned int irq)
         }
         desc->msi_desc = NULL;
         desc->handler_data = NULL;
-        desc->chip_data = NULL;
+        if (!keep_chip_data)
+                desc->chip_data = NULL;
         desc->handle_irq = handle_bad_irq;
         desc->chip = &no_irq_chip;
         desc->name = NULL;
@@ -85,6 +99,26 @@ void dynamic_irq_cleanup(unsigned int irq)
         raw_spin_unlock_irqrestore(&desc->lock, flags);
 }
 
+/**
+ *      dynamic_irq_cleanup - cleanup a dynamically allocated irq
+ *      @irq:   irq number to initialize
+ */
+void dynamic_irq_cleanup(unsigned int irq)
+{
+        dynamic_irq_cleanup_x(irq, false);
+}
+
+/**
+ *      dynamic_irq_cleanup_keep_chip_data - cleanup a dynamically allocated irq
+ *      @irq:   irq number to initialize
+ *
+ *      does not set irq_to_desc(irq)->chip_data to NULL
+ */
+void dynamic_irq_cleanup_keep_chip_data(unsigned int irq)
+{
+        dynamic_irq_cleanup_x(irq, true);
+}
+
 
 /**
  *      set_irq_chip - set the irq chip for an irq