skfddi.c

h内核

/************************
 *
 *	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
 *
 *	The HWM calls this function, when the driver leads through a DMA
 *	transfer. If the OS-specific module must prepare the system hardware
 *	for the DMA transfer, it should do it in this function.
 *
 *	The hardware module calls this dma_master if it wants to send an SMT
 *	frame.  This means that the virt address passed in here is part of
 *      the 'shared' memory area.
 * Args
 *	smc - A pointer to the SMT context struct.
 *
 *	virt - The virtual address of the data.
 *
 *	len - The length in bytes of the data.
 *
 *	flag - Indicates the transmit direction and the buffer type:
 *		DMA_RD	(0x01)	system RAM ==> adapter buffer memory
 *		DMA_WR	(0x02)	adapter buffer memory ==> system RAM
 *		SMT_BUF (0x80)	SMT buffer
 *
 *	>> NOTE: SMT_BUF and DMA_RD are always set for PCI. <<
 * Out
 *	Returns the pyhsical address for the DMA transfer.
 *
 ************************/
u_long dma_master(struct s_smc * smc, void *virt, int len, int flag)
{
	return (smc->os.SharedMemDMA +
		((char *) virt - (char *)smc->os.SharedMemAddr));
}				// dma_master


/************************
 *
 *	dma_complete
 *
 *	The hardware module calls this routine when it has completed a DMA
 *	transfer. If the operating system dependent module has set up the DMA
 *	channel via dma_master() (e.g. Windows NT or AIX) it should clean up
 *	the DMA channel.
 * Args
 *	smc - A pointer to the SMT context struct.
 *
 *	descr - A pointer to a TxD or RxD, respectively.
 *
 *	flag - Indicates the DMA transfer direction / SMT buffer:
 *		DMA_RD	(0x01)	system RAM ==> adapter buffer memory
 *		DMA_WR	(0x02)	adapter buffer memory ==> system RAM
 *		SMT_BUF (0x80)	SMT buffer (managed by HWM)
 * Out
 *	Nothing.
 *
 ************************/
void dma_complete(struct s_smc *smc, volatile union s_fp_descr *descr, int flag)
{
	/* For TX buffers, there are two cases.  If it is an SMT transmit
	 * buffer, there is nothing to do since we use consistent memory
	 * for the 'shared' memory area.  The other case is for normal
	 * transmit packets given to us by the networking stack, and in
	 * that case we cleanup the PCI DMA mapping in mac_drv_tx_complete
	 * below.
	 *
	 * For RX buffers, we have to unmap dynamic PCI DMA mappings here
	 * because the hardware module is about to potentially look at
	 * the contents of the buffer.  If we did not call the PCI DMA
	 * unmap first, the hardware module could read inconsistent data.
	 */
	if (flag & DMA_WR) {
		skfddi_priv *bp = &smc->os;
		volatile struct s_smt_fp_rxd *r = &descr->r;

		/* If SKB is NULL, we used the local buffer. */
		if (r->rxd_os.skb && r->rxd_os.dma_addr) {
			int MaxFrameSize = bp->MaxFrameSize;

			pci_unmap_single(&bp->pdev, r->rxd_os.dma_addr,
					 MaxFrameSize, PCI_DMA_FROMDEVICE);
			r->rxd_os.dma_addr = 0;
		}
	}
}				// dma_complete


/************************
 *
 *	mac_drv_tx_complete
 *
 *	Transmit of a packet is complete. Release the tx staging buffer.
 *
 * Args
 *	smc - A pointer to the SMT context struct.
 *
 *	txd - A pointer to the last TxD which is used by the frame.
 * Out
 *	Returns nothing.
 *
 ************************/
void mac_drv_tx_complete(struct s_smc *smc, volatile struct s_smt_fp_txd *txd)
{
	struct sk_buff *skb;

	PRINTK(KERN_INFO "entering mac_drv_tx_complete\n");
	// Check if this TxD points to a skb

	if (!(skb = txd->txd_os.skb)) {
		PRINTK("TXD with no skb assigned.\n");
		return;
	}
	txd->txd_os.skb = NULL;

	// release the DMA mapping
	pci_unmap_single(&smc->os.pdev, txd->txd_os.dma_addr,
			 skb->len, PCI_DMA_TODEVICE);
	txd->txd_os.dma_addr = 0;

	smc->os.MacStat.gen.tx_packets++;	// Count transmitted packets.
	smc->os.MacStat.gen.tx_bytes+=skb->len;	// Count bytes

	// free the skb
	dev_kfree_skb_irq(skb);

	PRINTK(KERN_INFO "leaving mac_drv_tx_complete\n");
}				// mac_drv_tx_complete


/************************
 *
 * dump packets to logfile
 *
 ************************/
#ifdef DUMPPACKETS
void dump_data(unsigned char *Data, int length)
{
	int i, j;
	unsigned char s[255], sh[10];
	if (length > 64) {
		length = 64;
	}
	printk(KERN_INFO "---Packet start---\n");
	for (i = 0, j = 0; i < length / 8; i++, j += 8)
		printk(KERN_INFO "%02x %02x %02x %02x %02x %02x %02x %02x\n",
		       Data[j + 0], Data[j + 1], Data[j + 2], Data[j + 3],
		       Data[j + 4], Data[j + 5], Data[j + 6], Data[j + 7]);
	strcpy(s, "");
	for (i = 0; i < length % 8; i++) {
		sprintf(sh, "%02x ", Data[j + i]);
		strcat(s, sh);
	}
	printk(KERN_INFO "%s\n", s);
	printk(KERN_INFO "------------------\n");
}				// dump_data
#else
#define dump_data(data,len)
#endif				// DUMPPACKETS

/************************
 *
 *	mac_drv_rx_complete
 *
 *	The hardware module calls this function if an LLC frame is received
 *	in a receive buffer. Also the SMT, NSA, and directed beacon frames
 *	from the network will be passed to the LLC layer by this function
 *	if passing is enabled.
 *
 *	mac_drv_rx_complete forwards the frame to the LLC layer if it should
 *	be received. It also fills the RxD ring with new receive buffers if
 *	some can be queued.
 * Args
 *	smc - A pointer to the SMT context struct.
 *
 *	rxd - A pointer to the first RxD which is used by the receive frame.
 *
 *	frag_count - Count of RxDs used by the received frame.
 *
 *	len - Frame length.
 * Out
 *	Nothing.
 *
 ************************/
void mac_drv_rx_complete(struct s_smc *smc, volatile struct s_smt_fp_rxd *rxd,
			 int frag_count, int len)
{
	skfddi_priv *bp = &smc->os;
	struct sk_buff *skb;
	unsigned char *virt, *cp;
	unsigned short ri;
	u_int RifLength;

	PRINTK(KERN_INFO "entering mac_drv_rx_complete (len=%d)\n", len);
	if (frag_count != 1) {	// This is not allowed to happen.

		printk("fddi: Multi-fragment receive!\n");
		goto RequeueRxd;	// Re-use the given RXD(s).

	}
	skb = rxd->rxd_os.skb;
	if (!skb) {
		PRINTK(KERN_INFO "No skb in rxd\n");
		smc->os.MacStat.gen.rx_errors++;
		goto RequeueRxd;
	}
	virt = skb->data;

	// The DMA mapping was released in dma_complete above.

	dump_data(skb->data, len);

	/*
	 * FDDI Frame format:
	 * +-------+-------+-------+------------+--------+------------+
	 * | FC[1] | DA[6] | SA[6] | RIF[0..18] | LLC[3] | Data[0..n] |
	 * +-------+-------+-------+------------+--------+------------+
	 *
	 * FC = Frame Control
	 * DA = Destination Address
	 * SA = Source Address
	 * RIF = Routing Information Field
	 * LLC = Logical Link Control
	 */

	// Remove Routing Information Field (RIF), if present.

	if ((virt[1 + 6] & FDDI_RII) == 0)
		RifLength = 0;
	else {
		int n;
// goos: RIF removal has still to be tested
		PRINTK(KERN_INFO "RIF found\n");
		// Get RIF length from Routing Control (RC) field.
		cp = virt + FDDI_MAC_HDR_LEN;	// Point behind MAC header.

		ri = ntohs(*((unsigned short *) cp));
		RifLength = ri & FDDI_RCF_LEN_MASK;
		if (len < (int) (FDDI_MAC_HDR_LEN + RifLength)) {
			printk("fddi: Invalid RIF.\n");
			goto RequeueRxd;	// Discard the frame.

		}
		virt[1 + 6] &= ~FDDI_RII;	// Clear RII bit.
		// regions overlap

		virt = cp + RifLength;
		for (n = FDDI_MAC_HDR_LEN; n; n--)
			*--virt = *--cp;
		// adjust sbd->data pointer
		skb_pull(skb, RifLength);
		len -= RifLength;
		RifLength = 0;
	}

	// Count statistics.
	smc->os.MacStat.gen.rx_packets++;	// Count indicated receive
						// packets.
	smc->os.MacStat.gen.rx_bytes+=len;	// Count bytes.

	// virt points to header again
	if (virt[1] & 0x01) {	// Check group (multicast) bit.

		smc->os.MacStat.gen.multicast++;
	}

	// deliver frame to system
	rxd->rxd_os.skb = NULL;
	skb_trim(skb, len);
	skb->protocol = fddi_type_trans(skb, bp->dev);
	skb->dev = bp->dev;	/* pass up device pointer */

	netif_rx(skb);
	bp->dev->last_rx = jiffies;

	HWM_RX_CHECK(smc, RX_LOW_WATERMARK);
	return;

      RequeueRxd:
	PRINTK(KERN_INFO "Rx: re-queue RXD.\n");
	mac_drv_requeue_rxd(smc, rxd, frag_count);
	smc->os.MacStat.gen.rx_errors++;	// Count receive packets
						// not indicated.

}				// mac_drv_rx_complete


/************************
 *
 *	mac_drv_requeue_rxd
 *
 *	The hardware module calls this function to request the OS-specific
 *	module to queue the receive buffer(s) represented by the pointer
 *	to the RxD and the frag_count into the receive queue again. This
 *	buffer was filled with an invalid frame or an SMT frame.
 * Args
 *	smc - A pointer to the SMT context struct.
 *
 *	rxd - A pointer to the first RxD which is used by the receive frame.
 *
 *	frag_count - Count of RxDs used by the received frame.
 * Out
 *	Nothing.
 *
 ************************/
void mac_drv_requeue_rxd(struct s_smc *smc, volatile struct s_smt_fp_rxd *rxd,
			 int frag_count)
{
	volatile struct s_smt_fp_rxd *next_rxd;
	volatile struct s_smt_fp_rxd *src_rxd;
	struct sk_buff *skb;
	int MaxFrameSize;
	unsigned char *v_addr;
	dma_addr_t b_addr;

	if (frag_count != 1)	// This is not allowed to happen.

		printk("fddi: Multi-fragment requeue!\n");

	MaxFrameSize = smc->os.MaxFrameSize;
	src_rxd = rxd;
	for (; frag_count > 0; frag_count--) {
		next_rxd = src_rxd->rxd_next;
		rxd = HWM_GET_CURR_RXD(smc);

		skb = src_rxd->rxd_os.skb;
		if (skb == NULL) {	// this should not happen

			PRINTK("Requeue with no skb in rxd!\n");
			skb = alloc_skb(MaxFrameSize + 3, GFP_ATOMIC);
			if (skb) {
				// we got a skb
				rxd->rxd_os.skb = skb;
				skb_reserve(skb, 3);
				skb_put(skb, MaxFrameSize);
				v_addr = skb->data;
				b_addr = pci_map_single(&smc->os.pdev,
							v_addr,
							MaxFrameSize,
							PCI_DMA_FROMDEVICE);
				rxd->rxd_os.dma_addr = b_addr;
			} else {
				// no skb available, use local buffer
				PRINTK("Queueing invalid buffer!\n");
				rxd->rxd_os.skb = NULL;
				v_addr = smc->os.LocalRxBuffer;
				b_addr = smc->os.LocalRxBufferDMA;
			}
		} else {
			// we use skb from old rxd
			rxd->rxd_os.skb = skb;
			v_addr = skb->data;
			b_addr = pci_map_single(&smc->os.pdev,
						v_addr,
						MaxFrameSize,
						PCI_DMA_FROMDEVICE);
			rxd->rxd_os.dma_addr = b_addr;
		}
		hwm_rx_frag(smc, v_addr, b_addr, MaxFrameSize,
			    FIRST_FRAG | LAST_FRAG);

		src_rxd = next_rxd;
	}
}				// mac_drv_requeue_rxd


/************************
 *
 *	mac_drv_fill_rxd
 *
 *	The hardware module calls this function at initialization time
 *	to fill the RxD ring with receive buffers. It is also called by
 *	mac_drv_rx_complete if rx_free is large enough to queue some new
 *	receive buffers into the RxD ring. mac_drv_fill_rxd queues new
 *	receive buffers as long as enough RxDs and receive buffers are
 *	available.
 * Args
 *	smc - A pointer to the SMT context struct.
 * Out
 *	Nothing.
 *
 ************************/
void mac_drv_fill_rxd(struct s_smc *smc)
{
	int MaxFrameSize;
	unsigned char *v_addr;
	unsigned long b_addr;
	struct sk_buff *skb;
	volatile struct s_smt_fp_rxd *rxd;