s390/airq: introduce adapter interrupt vector helper

The PCI code is the first user of adapter interrupts vectors.
Add a set of helpers to airq.c to separate the adatper interrupt
code from the PCI bits. The helpers allow for adapter interrupt
vectors of any size.

Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/arch/s390/include/asm/airq.h b/arch/s390/include/asm/airq.h
index 4066cee0c2d2..4bbb5957ed1b 100644
--- a/arch/s390/include/asm/airq.h
+++ b/arch/s390/include/asm/airq.h
@@ -9,6 +9,8 @@
 #ifndef _ASM_S390_AIRQ_H
 #define _ASM_S390_AIRQ_H
 
+#include <linux/bit_spinlock.h>
+
 struct airq_struct {
 	struct hlist_node list;		/* Handler queueing. */
 	void (*handler)(struct airq_struct *);	/* Thin-interrupt handler */
@@ -23,4 +25,69 @@ struct airq_struct {
 int register_adapter_interrupt(struct airq_struct *airq);
 void unregister_adapter_interrupt(struct airq_struct *airq);
 
+/* Adapter interrupt bit vector */
+struct airq_iv {
+	unsigned long *vector;	/* Adapter interrupt bit vector */
+	unsigned long *avail;	/* Allocation bit mask for the bit vector */
+	unsigned long *bitlock;	/* Lock bit mask for the bit vector */
+	unsigned long *ptr;	/* Pointer associated with each bit */
+	unsigned int *data;	/* 32 bit value associated with each bit */
+	unsigned long bits;	/* Number of bits in the vector */
+	unsigned long end;	/* Number of highest allocated bit + 1 */
+	spinlock_t lock;	/* Lock to protect alloc & free */
+};
+
+#define AIRQ_IV_ALLOC	1	/* Use an allocation bit mask */
+#define AIRQ_IV_BITLOCK	2	/* Allocate the lock bit mask */
+#define AIRQ_IV_PTR	4	/* Allocate the ptr array */
+#define AIRQ_IV_DATA	8	/* Allocate the data array */
+
+struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags);
+void airq_iv_release(struct airq_iv *iv);
+unsigned long airq_iv_alloc_bit(struct airq_iv *iv);
+void airq_iv_free_bit(struct airq_iv *iv, unsigned long bit);
+unsigned long airq_iv_scan(struct airq_iv *iv, unsigned long start,
+			   unsigned long end);
+
+static inline unsigned long airq_iv_end(struct airq_iv *iv)
+{
+	return iv->end;
+}
+
+static inline void airq_iv_lock(struct airq_iv *iv, unsigned long bit)
+{
+	const unsigned long be_to_le = BITS_PER_LONG - 1;
+	bit_spin_lock(bit ^ be_to_le, iv->bitlock);
+}
+
+static inline void airq_iv_unlock(struct airq_iv *iv, unsigned long bit)
+{
+	const unsigned long be_to_le = BITS_PER_LONG - 1;
+	bit_spin_unlock(bit ^ be_to_le, iv->bitlock);
+}
+
+static inline void airq_iv_set_data(struct airq_iv *iv, unsigned long bit,
+				    unsigned int data)
+{
+	iv->data[bit] = data;
+}
+
+static inline unsigned int airq_iv_get_data(struct airq_iv *iv,
+					    unsigned long bit)
+{
+	return iv->data[bit];
+}
+
+static inline void airq_iv_set_ptr(struct airq_iv *iv, unsigned long bit,
+				   unsigned long ptr)
+{
+	iv->ptr[bit] = ptr;
+}
+
+static inline unsigned long airq_iv_get_ptr(struct airq_iv *iv,
+					    unsigned long bit)
+{
+	return iv->ptr[bit];
+}
+
 #endif /* _ASM_S390_AIRQ_H */