skfddi.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

	skfddi_priv *lp = PRIV(dev);
	struct s_skfp_ioctl ioc;
	int status = 0;

	copy_from_user(&ioc, rq->ifr_data, sizeof(struct s_skfp_ioctl));
	switch (ioc.cmd) {
	case SKFP_GET_STATS:	/* Get the driver statistics */
		ioc.len = sizeof(lp->MacStat);
		copy_to_user(ioc.data, skfp_ctl_get_stats(dev), ioc.len);
		break;
	case SKFP_CLR_STATS:	/* Zero out the driver statistics */
		if (!capable(CAP_NET_ADMIN)) {
			memset(&lp->MacStat, 0, sizeof(lp->MacStat));
		} else {
			status = -EPERM;
		}
		break;
	default:
		printk("ioctl for %s: unknow cmd: %04x\n", dev->name, ioc.cmd);
	}			// switch

	return status;
}				// skfp_ioctl


/*
 * =====================
 * = skfp_send_pkt     =
 * =====================
 *   
 * Overview:
 *   Queues a packet for transmission and try to transmit it.
 *  
 * Returns:
 *   Condition code
 *       
 * Arguments:
 *   skb - pointer to sk_buff to queue for transmission
 *   dev - pointer to device information
 *
 * Functional Description:
 *   Here we assume that an incoming skb transmit request
 *   is contained in a single physically contiguous buffer
 *   in which the virtual address of the start of packet
 *   (skb->data) can be converted to a physical address
 *   by using pci_map_single().
 *
 *   We have an internal queue for packets we can not send 
 *   immediately. Packets in this queue can be given to the 
 *   adapter if transmit buffers are freed.
 *
 *   We can't free the skb until after it's been DMA'd
 *   out by the adapter, so we'll keep it in the driver and
 *   return it in mac_drv_tx_complete.
 *
 * Return Codes:
 *   0 - driver has queued and/or sent packet
 *       1 - caller should requeue the sk_buff for later transmission
 *
 * Assumptions:
 *   The entire packet is stored in one physically
 *   contiguous buffer which is not cached and whose
 *   32-bit physical address can be determined.
 *
 *   It's vital that this routine is NOT reentered for the
 *   same board and that the OS is not in another section of
 *   code (eg. skfp_interrupt) for the same board on a
 *   different thread.
 *
 * Side Effects:
 *   None
 */
static int skfp_send_pkt(struct sk_buff *skb, struct net_device *dev)
{
	skfddi_priv *bp = PRIV(dev);

	PRINTK(KERN_INFO "skfp_send_pkt\n");

	/*
	 * Verify that incoming transmit request is OK
	 *
	 * Note: The packet size check is consistent with other
	 *               Linux device drivers, although the correct packet
	 *               size should be verified before calling the
	 *               transmit routine.
	 */

	if (!(skb->len >= FDDI_K_LLC_ZLEN && skb->len <= FDDI_K_LLC_LEN)) {
		bp->MacStat.tx_errors++;	/* bump error counter */
		// dequeue packets from xmt queue and send them
		netif_start_queue(dev);
		dev_kfree_skb(skb);
		return (0);	/* return "success" */
	}
	if (bp->QueueSkb == 0) {	// return with tbusy set: queue full

		netif_stop_queue(dev);
		return 1;
	}
	bp->QueueSkb--;
	skb_queue_tail(&bp->SendSkbQueue, skb);
	send_queued_packets((struct s_smc *) dev->priv);
	if (bp->QueueSkb == 0) {
		netif_stop_queue(dev);
	}
	dev->trans_start = jiffies;
	return 0;

}				// skfp_send_pkt


/*
 * =======================
 * = send_queued_packets =
 * =======================
 *   
 * Overview:
 *   Send packets from the driver queue as long as there are some and
 *   transmit resources are available.
 *  
 * Returns:
 *   None
 *       
 * Arguments:
 *   smc - pointer to smc (adapter) structure
 *
 * Functional Description:
 *   Take a packet from queue if there is any. If not, then we are done.
 *   Check if there are resources to send the packet. If not, requeue it
 *   and exit. 
 *   Set packet descriptor flags and give packet to adapter.
 *   Check if any send resources can be freed (we do not use the
 *   transmit complete interrupt).
 */
static void send_queued_packets(struct s_smc *smc)
{
	skfddi_priv *bp = (skfddi_priv *) & smc->os;
	struct sk_buff *skb;
	unsigned char fc;
	int queue;
	struct s_smt_fp_txd *txd;	// Current TxD.
	dma_addr_t dma_address;
	unsigned long Flags;

	int frame_status;	// HWM tx frame status.

	PRINTK(KERN_INFO "send queued packets\n");
	for (;;) {
		// send first buffer from queue
		skb = skb_dequeue(&bp->SendSkbQueue);

		if (!skb) {
			PRINTK(KERN_INFO "queue empty\n");
			return;
		}		// queue empty !

		spin_lock_irqsave(&bp->DriverLock, Flags);
		fc = skb->data[0];
		queue = (fc & FC_SYNC_BIT) ? QUEUE_S : QUEUE_A0;
#ifdef ESS
		// Check if the frame may/must be sent as a synchronous frame.

		if ((fc & ~(FC_SYNC_BIT | FC_LLC_PRIOR)) == FC_ASYNC_LLC) {
			// It's an LLC frame.
			if (!smc->ess.sync_bw_available)
				fc &= ~FC_SYNC_BIT; // No bandwidth available.

			else {	// Bandwidth is available.

				if (smc->mib.fddiESSSynchTxMode) {
					// Send as sync. frame.
					fc |= FC_SYNC_BIT;
				}
			}
		}
#endif				// ESS
		frame_status = hwm_tx_init(smc, fc, 1, skb->len, queue);

		if ((frame_status & (LOC_TX | LAN_TX)) == 0) {
			// Unable to send the frame.

			if ((frame_status & RING_DOWN) != 0) {
				// Ring is down.
				PRINTK("Tx attempt while ring down.\n");
			} else if ((frame_status & OUT_OF_TXD) != 0) {
				PRINTK("%s: out of TXDs.\n", bp->dev->name);
			} else {
				PRINTK("%s: out of transmit resources",
					bp->dev->name);
			}

			// Note: We will retry the operation as soon as
			// transmit resources become available.
			skb_queue_head(&bp->SendSkbQueue, skb);
			spin_unlock_irqrestore(&bp->DriverLock, Flags);
			return;	// Packet has been queued.

		}		// if (unable to send frame)

		bp->QueueSkb++;	// one packet less in local queue

		// source address in packet ?
		CheckSourceAddress(skb->data, smc->hw.fddi_canon_addr.a);

		txd = (struct s_smt_fp_txd *) HWM_GET_CURR_TXD(smc, queue);

		dma_address = pci_map_single(&bp->pdev, skb->data,
					     skb->len, PCI_DMA_TODEVICE);
		if (frame_status & LAN_TX) {
			txd->txd_os.skb = skb;			// save skb
			txd->txd_os.dma_addr = dma_address;	// save dma mapping
		}
		hwm_tx_frag(smc, skb->data, dma_address, skb->len,
                      frame_status | FIRST_FRAG | LAST_FRAG | EN_IRQ_EOF);

		if (!(frame_status & LAN_TX)) {		// local only frame
			pci_unmap_single(&bp->pdev, dma_address,
					 skb->len, PCI_DMA_TODEVICE);
			dev_kfree_skb_irq(skb);
		}
		spin_unlock_irqrestore(&bp->DriverLock, Flags);
	}			// for

	return;			// never reached

}				// send_queued_packets


/************************
 * 
 * CheckSourceAddress
 *
 * Verify if the source address is set. Insert it if necessary.
 *
 ************************/
void CheckSourceAddress(unsigned char *frame, unsigned char *hw_addr)
{
	unsigned char SRBit;

	if ((((unsigned long) frame[1 + 6]) & ~0x01) != 0) // source routing bit

		return;
	if ((unsigned short) frame[1 + 10] != 0)
		return;
	SRBit = frame[1 + 6] & 0x01;
	memcpy(&frame[1 + 6], hw_addr, 6);
	frame[8] |= SRBit;
}				// CheckSourceAddress


/************************
 *
 *	ResetAdapter
 *
 *	Reset the adapter and bring it back to operational mode.
 * Args
 *	smc - A pointer to the SMT context struct.
 * Out
 *	Nothing.
 *
 ************************/
static void ResetAdapter(struct s_smc *smc)
{

	PRINTK(KERN_INFO "[fddi: ResetAdapter]\n");

	// Stop the adapter.

	card_stop(smc);		// Stop all activity.

	// Clear the transmit and receive descriptor queues.
	mac_drv_clear_tx_queue(smc);
	mac_drv_clear_rx_queue(smc);

	// Restart the adapter.

	smt_reset_defaults(smc, 1);	// Initialize the SMT module.

	init_smt(smc, (smc->os.dev)->dev_addr);	// Initialize the hardware.

	smt_online(smc, 1);	// Insert into the ring again.
	STI_FBI();

	// Restore original receive mode (multicasts, promiscuous, etc.).
	skfp_ctl_set_multicast_list_wo_lock(smc->os.dev);
}				// ResetAdapter


//--------------- functions called by hardware module ----------------

/************************
 *
 *	llc_restart_tx
 *
 *	The hardware driver calls this routine when the transmit complete
 *	interrupt bits (end of frame) for the synchronous or asynchronous
 *	queue is set.
 *
 * NOTE The hardware driver calls this function also if no packets are queued.
 *	The routine must be able to handle this case.
 * Args
 *	smc - A pointer to the SMT context struct.
 * Out
 *	Nothing.
 *
 ************************/
void llc_restart_tx(struct s_smc *smc)
{
	skfddi_priv *bp = (skfddi_priv *) & smc->os;

	PRINTK(KERN_INFO "[llc_restart_tx]\n");

	// Try to send queued packets
	spin_unlock(&bp->DriverLock);
	send_queued_packets(smc);
	spin_lock(&bp->DriverLock);
	netif_start_queue(bp->dev);// system may send again if it was blocked

}				// llc_restart_tx


/************************
 *
 *	mac_drv_get_space
 *
 *	The hardware module calls this function to allocate the memory
 *	for the SMT MBufs if the define MB_OUTSIDE_SMC is specified.
 * Args
 *	smc - A pointer to the SMT context struct.
 *
 *	size - Size of memory in bytes to allocate.
 * Out
 *	!= 0	A pointer to the virtual address of the allocated memory.
 *	== 0	Allocation error.
 *
 ************************/
void *mac_drv_get_space(struct s_smc *smc, unsigned int size)
{
	void *virt;

	PRINTK(KERN_INFO "mac_drv_get_space (%d bytes), ", size);
	virt = (void *) (smc->os.SharedMemAddr + smc->os.SharedMemHeap);

	if ((smc->os.SharedMemHeap + size) > smc->os.SharedMemSize) {
		printk("Unexpected SMT memory size requested: %d\n", size);
		return (NULL);
	}
	smc->os.SharedMemHeap += size;	// Move heap pointer.

	PRINTK(KERN_INFO "mac_drv_get_space end\n");
	PRINTK(KERN_INFO "virt addr: %lx\n", (ulong) virt);
	PRINTK(KERN_INFO "bus  addr: %lx\n", (ulong)
	       (smc->os.SharedMemDMA +
		((char *) virt - (char *)smc->os.SharedMemAddr)));
	return (virt);
}				// mac_drv_get_space


/************************
 *
 *	mac_drv_get_desc_mem
 *
 *	This function is called by the hardware dependent module.
 *	It allocates the memory for the RxD and TxD descriptors.
 *
 *	This memory must be non-cached, non-movable and non-swappable.
 *	This memory should start at a physical page boundary.
 * Args
 *	smc - A pointer to the SMT context struct.
 *
 *	size - Size of memory in bytes to allocate.
 * Out
 *	!= 0	A pointer to the virtual address of the allocated memory.
 *	== 0	Allocation error.
 *
 ************************/
void *mac_drv_get_desc_mem(struct s_smc *smc, unsigned int size)
{

	char *virt;

	PRINTK(KERN_INFO "mac_drv_get_desc_mem\n");

	// Descriptor memory must be aligned on 16-byte boundary.

	virt = mac_drv_get_space(smc, size);

	size = (u_int) (16 - (((unsigned long) virt) & 15UL));
	size = size % 16;

	PRINTK("Allocate %u bytes alignment gap ", size);
	PRINTK("for descriptor memory.\n");

	if (!mac_drv_get_space(smc, size)) {
		printk("fddi: Unable to align descriptor memory.\n");
		return (NULL);
	}
	return (virt + size);
}				// mac_drv_get_desc_mem


/************************
 *
 *	mac_drv_virt2phys
 *
 *	Get the physical address of a given virtual address.
 * Args
 *	smc - A pointer to the SMT context struct.
 *
 *	virt - A (virtual) pointer into our 'shared' memory area.
 * Out
 *	Physical address of the given virtual address.
 *
 ************************/
unsigned long mac_drv_virt2phys(struct s_smc *smc, void *virt)
{
	return (smc->os.SharedMemDMA +
		((char *) virt - (char *)smc->os.SharedMemAddr));
}				// mac_drv_virt2phys


/************************
 *
 *	dma_master
 *