qlge: Allow RX buf rings to be > than 4096 bytes.

RX buffer rings can be comprised of non-contiguous fixed
size chunks of memory. The ring is given to the hardware
as a pointer to a location that stores the location of
the queue.  If the queue is greater than 4096 bytes then
the hardware gets a list of said pointers.
This patch addes the necessary logic to generate the list if
the queue size exceeds 4096.

Signed-off-by: Ron Mercer <ron.mercer@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/qlge/qlge.h b/drivers/net/qlge/qlge.h
index b1ddfd1..156e02e 100644
--- a/drivers/net/qlge/qlge.h
+++ b/drivers/net/qlge/qlge.h
@@ -41,7 +41,18 @@
 
 #define NUM_SMALL_BUFFERS   512
 #define NUM_LARGE_BUFFERS   512
+#define DB_PAGE_SIZE 4096
 
+/* Calculate the number of (4k) pages required to
+ * contain a buffer queue of the given length.
+ */
+#define MAX_DB_PAGES_PER_BQ(x) \
+		(((x * sizeof(u64)) / DB_PAGE_SIZE) + \
+		(((x * sizeof(u64)) % DB_PAGE_SIZE) ? 1 : 0))
+
+#define RX_RING_SHADOW_SPACE	(sizeof(u64) + \
+		MAX_DB_PAGES_PER_BQ(NUM_SMALL_BUFFERS) * sizeof(u64) + \
+		MAX_DB_PAGES_PER_BQ(NUM_LARGE_BUFFERS) * sizeof(u64))
 #define SMALL_BUFFER_SIZE 256
 #define LARGE_BUFFER_SIZE	PAGE_SIZE
 #define MAX_SPLIT_SIZE 1023
@@ -65,8 +76,6 @@
 #define TX_DESC_PER_OAL 0
 #endif
 
-#define DB_PAGE_SIZE 4096
-
 /* MPI test register definitions. This register
  * is used for determining alternate NIC function's
  * PCI->func number.