genirq: Create irq_data

Low level chip functions need access to irq_desc->handler_data,
irq_desc->chip_data and irq_desc->msi_desc. We hand down the irq
number to the low level functions, so they need to lookup irq_desc.
With sparse irq this means a radix tree lookup.

We could hand down irq_desc itself, but low level chip functions have
no need to fiddle with it directly and we want to restrict access to
irq_desc further.

Preparatory patch for new chip functions.

Note, that the ugly anon union/struct is there to avoid a full tree
wide clean up for now. This is not going to last 3 years like __do_IRQ()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121841.645542300@linutronix.de>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 63 insertions, 27 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 06273a2a17e7..363c76ff82c8 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -84,6 +84,37 @@ struct proc_dir_entry;
 struct msi_desc;
 
 /**
+ * struct irq_data - per irq and irq chip data passed down to chip functions
+ * @irq:                interrupt number
+ * @node:               node index useful for balancing
+ * @chip:               low level interrupt hardware access
+ * @handler_data:       per-IRQ data for the irq_chip methods
+ * @chip_data:          platform-specific per-chip private data for the chip
+ *                      methods, to allow shared chip implementations
+ * @msi_desc:           MSI descriptor
+ * @affinity:           IRQ affinity on SMP
+ * @irq_2_iommu:        iommu with this irq
+ *
+ * The fields here need to overlay the ones in irq_desc until we
+ * cleaned up the direct references and switched everything over to
+ * irq_data.
+ */
+struct irq_data {
+        unsigned int            irq;
+        unsigned int            node;
+        struct irq_chip         *chip;
+        void                    *handler_data;
+        void                    *chip_data;
+        struct msi_desc         *msi_desc;
+#ifdef CONFIG_SMP
+        cpumask_var_t           affinity;
+#endif
+#ifdef CONFIG_INTR_REMAP
+        struct irq_2_iommu      *irq_2_iommu;
+#endif
+};
+
+/**
  * struct irq_chip - hardware interrupt chip descriptor
  *
  * @name:               name for /proc/interrupts
@@ -140,16 +171,10 @@ struct timer_rand_state;
 struct irq_2_iommu;
 /**
  * struct irq_desc - interrupt descriptor
- * @irq:                interrupt number for this descriptor
+ * @irq_data:           per irq and chip data passed down to chip functions
  * @timer_rand_state:   pointer to timer rand state struct
  * @kstat_irqs:         irq stats per cpu
- * @irq_2_iommu:        iommu with this irq
  * @handle_irq:         highlevel irq-events handler [if NULL, __do_IRQ()]
- * @chip:               low level interrupt hardware access
- * @msi_desc:           MSI descriptor
- * @handler_data:       per-IRQ data for the irq_chip methods
- * @chip_data:          platform-specific per-chip private data for the chip
- *                      methods, to allow shared chip implementations
  * @action:             the irq action chain
  * @status:             status information
  * @depth:              disable-depth, for nested irq_disable() calls
@@ -158,8 +183,6 @@ struct irq_2_iommu;
  * @last_unhandled:     aging timer for unhandled count
  * @irqs_unhandled:     stats field for spurious unhandled interrupts
  * @lock:               locking for SMP
- * @affinity:           IRQ affinity on SMP
- * @node:               node index useful for balancing
  * @pending_mask:       pending rebalanced interrupts
  * @threads_active:     number of irqaction threads currently running
  * @wait_for_threads:   wait queue for sync_irq to wait for threaded handlers
@@ -167,17 +190,32 @@ struct irq_2_iommu;
  * @name:               flow handler name for /proc/interrupts output
  */
 struct irq_desc {
-        unsigned int            irq;
-        struct timer_rand_state *timer_rand_state;
-        unsigned int            *kstat_irqs;
+
+        /*
+         * This union will go away, once we fixed the direct access to
+         * irq_desc all over the place. The direct fields are a 1:1
+         * overlay of irq_data.
+         */
+        union {
+                struct irq_data         irq_data;
+                struct {
+                        unsigned int            irq;
+                        unsigned int            node;
+                        struct irq_chip         *chip;
+                        void                    *handler_data;
+                        void                    *chip_data;
+                        struct msi_desc         *msi_desc;
+#ifdef CONFIG_SMP
+                        cpumask_var_t           affinity;
+#endif
 #ifdef CONFIG_INTR_REMAP
-        struct irq_2_iommu      *irq_2_iommu;
+                        struct irq_2_iommu      *irq_2_iommu;
 #endif
+                };
+        };
+        struct timer_rand_state *timer_rand_state;
+        unsigned int            *kstat_irqs;
         irq_flow_handler_t      handle_irq;
-        struct irq_chip         *chip;
-        struct msi_desc         *msi_desc;
-        void                    *handler_data;
-        void                    *chip_data;
         struct irqaction        *action;        /* IRQ action list */
         unsigned int            status;         /* IRQ status */
 
@@ -188,9 +226,7 @@ struct irq_desc {
         unsigned int            irqs_unhandled;
         raw_spinlock_t          lock;
 #ifdef CONFIG_SMP
-        cpumask_var_t           affinity;
         const struct cpumask    *affinity_hint;
-        unsigned int            node;
 #ifdef CONFIG_GENERIC_PENDING_IRQ
         cpumask_var_t           pending_mask;
 #endif
@@ -406,15 +442,15 @@ extern int set_irq_chip_data(unsigned int irq, void *data);
 extern int set_irq_type(unsigned int irq, unsigned int type);
 extern int set_irq_msi(unsigned int irq, struct msi_desc *entry);
 
-#define get_irq_chip(irq)       (irq_to_desc(irq)->chip)
-#define get_irq_chip_data(irq)  (irq_to_desc(irq)->chip_data)
-#define get_irq_data(irq)       (irq_to_desc(irq)->handler_data)
-#define get_irq_msi(irq)        (irq_to_desc(irq)->msi_desc)
+#define get_irq_chip(irq)       (irq_to_desc(irq)->irq_data.chip)
+#define get_irq_chip_data(irq)  (irq_to_desc(irq)->irq_data.chip_data)
+#define get_irq_data(irq)       (irq_to_desc(irq)->irq_data.handler_data)
+#define get_irq_msi(irq)        (irq_to_desc(irq)->irq_data.msi_desc)
 
-#define get_irq_desc_chip(desc)         ((desc)->chip)
-#define get_irq_desc_chip_data(desc)    ((desc)->chip_data)
-#define get_irq_desc_data(desc)         ((desc)->handler_data)
-#define get_irq_desc_msi(desc)          ((desc)->msi_desc)
+#define get_irq_desc_chip(desc)         ((desc)->irq_data.chip)
+#define get_irq_desc_chip_data(desc)    ((desc)->irq_data.chip_data)
+#define get_irq_desc_data(desc)         ((desc)->irq_data.handler_data)
+#define get_irq_desc_msi(desc)          ((desc)->irq_data.msi_desc)
 
 #endif /* CONFIG_GENERIC_HARDIRQS */