s390/pci: improve ZPCI_* macros

Most of the constants defined in pci_io.h depend on each other
and thus can be calculated.

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

arch/s390/include/asm/pci_io.h

@@ -8,10 +8,13 @@
 #include <asm/pci_insn.h>
 
 /* I/O Map */
-#define ZPCI_IOMAP_MAX_ENTRIES		0x8000
-#define ZPCI_IOMAP_ADDR_BASE		0x8000000000000000ULL
-#define ZPCI_IOMAP_ADDR_IDX_MASK	0x7fff000000000000ULL
-#define ZPCI_IOMAP_ADDR_OFF_MASK	0x0000ffffffffffffULL
+#define ZPCI_IOMAP_SHIFT		48
+#define ZPCI_IOMAP_ADDR_BASE		0x8000000000000000UL
+#define ZPCI_IOMAP_ADDR_OFF_MASK	((1UL << ZPCI_IOMAP_SHIFT) - 1)
+#define ZPCI_IOMAP_MAX_ENTRIES							\
+	((ULONG_MAX - ZPCI_IOMAP_ADDR_BASE + 1) / (1UL << ZPCI_IOMAP_SHIFT))
+#define ZPCI_IOMAP_ADDR_IDX_MASK						\
+	(~ZPCI_IOMAP_ADDR_OFF_MASK - ZPCI_IOMAP_ADDR_BASE)
 
 struct zpci_iomap_entry {
 	u32 fh;
@@ -21,9 +24,9 @@ struct zpci_iomap_entry {
 
 extern struct zpci_iomap_entry *zpci_iomap_start;
 
-#define ZPCI_ADDR(idx) (ZPCI_IOMAP_ADDR_BASE | ((u64) idx << 48))
+#define ZPCI_ADDR(idx) (ZPCI_IOMAP_ADDR_BASE | ((u64) idx << ZPCI_IOMAP_SHIFT))
 #define ZPCI_IDX(addr)								\
-	(((__force u64) addr & ZPCI_IOMAP_ADDR_IDX_MASK) >> 48)
+	(((__force u64) addr & ZPCI_IOMAP_ADDR_IDX_MASK) >> ZPCI_IOMAP_SHIFT)
 #define ZPCI_OFFSET(addr)							\
 	((__force u64) addr & ZPCI_IOMAP_ADDR_OFF_MASK)
 

arch/s390/pci/pci.c

@@ -541,7 +541,7 @@ static void zpci_irq_exit(void)
 
 static int zpci_alloc_iomap(struct zpci_dev *zdev)
 {
-	int entry;
+	unsigned long entry;
 
 	spin_lock(&zpci_iomap_lock);
 	entry = find_first_zero_bit(zpci_iomap, ZPCI_IOMAP_MAX_ENTRIES);