[PATCH] S2io: new txd allocation

The attached patch contains a modified scheme for allocating Tx descriptor
blocks.
More description follows.

In the old scheme, the entire Tx descriptor space was allocated in
one go. This could cause driver load to fail on systems with low(or
scattered) memory. The Tx descriptor blocks are now allocated on
per-page basis. A new structure (list_info) has been introduced in
nic_t structure to keep track of the physical and virtual addresses
of every TxD allocated this way.
Signed-off-by: Raghavendra Koushik <raghavendra.koushik@s2io.com>
Signed-off-by: Ravinandan Arakali <ravinandan.arakali@s2io.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/net/s2io.h

@@ -444,6 +444,12 @@ typedef struct _TxD {
 	u64 Host_Control;	/* reserved for host */
 } TxD_t;
 
+/* Structure to hold the phy and virt addr of every TxDL. */
+typedef struct list_info_hold {
+	dma_addr_t list_phy_addr;
+	void *list_virt_addr;
+} list_info_hold_t;
+
 /* Rx descriptor structure */
 typedef struct _RxD_t {
 	u64 Host_Control;	/* reserved for host */
@@ -532,17 +538,9 @@ typedef struct mac_info {
 	u16 mc_pause_threshold_q4q7;
 
 /* tx side stuff */
-	void *txd_list_mem;	/* original pointer to allocated mem */
-	dma_addr_t txd_list_mem_phy;
-	u32 txd_list_mem_sz;
-
 	/* logical pointer of start of each Tx FIFO */
 	TxFIFO_element_t *tx_FIFO_start[MAX_TX_FIFOS];
 
-	/* The Phy and virtual mem loactions of the Tx descriptors. */
-	TxD_t *txdl_start[MAX_TX_FIFOS];
-	dma_addr_t txdl_start_phy[MAX_TX_FIFOS];
-
 /* Current offset within tx_FIFO_start, where driver would write new Tx frame*/
 	tx_curr_put_info_t tx_curr_put_info[MAX_TX_FIFOS];
 	tx_curr_get_info_t tx_curr_get_info[MAX_TX_FIFOS];
@@ -638,6 +636,9 @@ typedef struct s2io_nic {
 	int block_count[MAX_RX_RINGS];
 	int pkt_cnt[MAX_RX_RINGS];
 
+	/* Place holder of all the TX List's Phy and Virt addresses. */
+	list_info_hold_t *list_info[MAX_TX_FIFOS];
+
 	/*  Id timer, used to blink NIC to physically identify NIC. */
 	struct timer_list id_timer;