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 */