NTB: Use DMA Engine to Transmit and Receive (282a2fee) · Commits · e / devices / android_kernel_xiaomi_nabu

drivers/ntb/ntb_hw.c

+17 −0

Original line number	Original line	Diff line number	Diff line
	@@ -349,6 +349,23 @@ int ntb_read_remote_spad(struct ntb_device ndev, unsigned int idx, u32 val)
	return 0;		return 0;
	}		}

			/**
			* ntb_get_mw_base() - get addr for the NTB memory window
			* @ndev: pointer to ntb_device instance
			* @mw: memory window number
			*
			* This function provides the base address of the memory window specified.
			*
			* RETURNS: address, or NULL on error.
			*/
			resource_size_t ntb_get_mw_base(struct ntb_device *ndev, unsigned int mw)
			{
			if (mw >= ntb_max_mw(ndev))
			return 0;

			return pci_resource_start(ndev->pdev, MW_TO_BAR(mw));
			}

	/**		/**
	* ntb_get_mw_vbase() - get virtual addr for the NTB memory window		* ntb_get_mw_vbase() - get virtual addr for the NTB memory window
	* @ndev: pointer to ntb_device instance		* @ndev: pointer to ntb_device instance

drivers/ntb/ntb_hw.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -240,6 +240,7 @@ int ntb_write_local_spad(struct ntb_device *ndev, unsigned int idx, u32 val);
	int ntb_read_local_spad(struct ntb_device ndev, unsigned int idx, u32 val);		int ntb_read_local_spad(struct ntb_device ndev, unsigned int idx, u32 val);
	int ntb_write_remote_spad(struct ntb_device *ndev, unsigned int idx, u32 val);		int ntb_write_remote_spad(struct ntb_device *ndev, unsigned int idx, u32 val);
	int ntb_read_remote_spad(struct ntb_device ndev, unsigned int idx, u32 val);		int ntb_read_remote_spad(struct ntb_device ndev, unsigned int idx, u32 val);
			resource_size_t ntb_get_mw_base(struct ntb_device *ndev, unsigned int mw);
	void __iomem ntb_get_mw_vbase(struct ntb_device ndev, unsigned int mw);		void __iomem ntb_get_mw_vbase(struct ntb_device ndev, unsigned int mw);
	u64 ntb_get_mw_size(struct ntb_device *ndev, unsigned int mw);		u64 ntb_get_mw_size(struct ntb_device *ndev, unsigned int mw);
	void ntb_ring_sdb(struct ntb_device *ndev, unsigned int idx);		void ntb_ring_sdb(struct ntb_device *ndev, unsigned int idx);

drivers/ntb/ntb_transport.c

+277 −47

Original line number	Original line	Diff line number	Diff line
	@@ -47,6 +47,7 @@
	*/		*/
	#include <linux/debugfs.h>		#include <linux/debugfs.h>
	#include <linux/delay.h>		#include <linux/delay.h>
			#include <linux/dmaengine.h>
	#include <linux/dma-mapping.h>		#include <linux/dma-mapping.h>
	#include <linux/errno.h>		#include <linux/errno.h>
	#include <linux/export.h>		#include <linux/export.h>
	@@ -68,6 +69,10 @@ static unsigned char max_num_clients;
	module_param(max_num_clients, byte, 0644);		module_param(max_num_clients, byte, 0644);
	MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");		MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");

			static unsigned int copy_bytes = 1024;
			module_param(copy_bytes, uint, 0644);
			MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");

	struct ntb_queue_entry {		struct ntb_queue_entry {
	/* ntb_queue list reference */		/* ntb_queue list reference */
	struct list_head entry;		struct list_head entry;
	@@ -76,6 +81,13 @@ struct ntb_queue_entry {
	void *buf;		void *buf;
	unsigned int len;		unsigned int len;
	unsigned int flags;		unsigned int flags;

			struct ntb_transport_qp *qp;
			union {
			struct ntb_payload_header __iomem *tx_hdr;
			struct ntb_payload_header *rx_hdr;
			};
			unsigned int index;
	};		};

	struct ntb_rx_info {		struct ntb_rx_info {
	@@ -86,6 +98,7 @@ struct ntb_transport_qp {
	struct ntb_transport *transport;		struct ntb_transport *transport;
	struct ntb_device *ndev;		struct ntb_device *ndev;
	void *cb_data;		void *cb_data;
			struct dma_chan *dma_chan;

	bool client_ready;		bool client_ready;
	bool qp_link;		bool qp_link;
	@@ -99,6 +112,7 @@ struct ntb_transport_qp {
	struct list_head tx_free_q;		struct list_head tx_free_q;
	spinlock_t ntb_tx_free_q_lock;		spinlock_t ntb_tx_free_q_lock;
	void __iomem *tx_mw;		void __iomem *tx_mw;
			dma_addr_t tx_mw_phys;
	unsigned int tx_index;		unsigned int tx_index;
	unsigned int tx_max_entry;		unsigned int tx_max_entry;
	unsigned int tx_max_frame;		unsigned int tx_max_frame;
	@@ -114,6 +128,7 @@ struct ntb_transport_qp {
	unsigned int rx_index;		unsigned int rx_index;
	unsigned int rx_max_entry;		unsigned int rx_max_entry;
	unsigned int rx_max_frame;		unsigned int rx_max_frame;
			dma_cookie_t last_cookie;

	void (event_handler) (void data, int status);		void (event_handler) (void data, int status);
	struct delayed_work link_work;		struct delayed_work link_work;
	@@ -129,9 +144,14 @@ struct ntb_transport_qp {
	u64 rx_err_no_buf;		u64 rx_err_no_buf;
	u64 rx_err_oflow;		u64 rx_err_oflow;
	u64 rx_err_ver;		u64 rx_err_ver;
			u64 rx_memcpy;
			u64 rx_async;
	u64 tx_bytes;		u64 tx_bytes;
	u64 tx_pkts;		u64 tx_pkts;
	u64 tx_ring_full;		u64 tx_ring_full;
			u64 tx_err_no_buf;
			u64 tx_memcpy;
			u64 tx_async;
	};		};

	struct ntb_transport_mw {		struct ntb_transport_mw {
	@@ -381,7 +401,7 @@ static ssize_t debugfs_read(struct file filp, char __user ubuf, size_t count,
	char *buf;		char *buf;
	ssize_t ret, out_offset, out_count;		ssize_t ret, out_offset, out_count;

	out_count = 600;		out_count = 1000;

	buf = kmalloc(out_count, GFP_KERNEL);		buf = kmalloc(out_count, GFP_KERNEL);
	if (!buf)		if (!buf)
	@@ -395,6 +415,10 @@ static ssize_t debugfs_read(struct file filp, char __user ubuf, size_t count,
	"rx_bytes - \t%llu\n", qp->rx_bytes);		"rx_bytes - \t%llu\n", qp->rx_bytes);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,		out_offset += snprintf(buf + out_offset, out_count - out_offset,
	"rx_pkts - \t%llu\n", qp->rx_pkts);		"rx_pkts - \t%llu\n", qp->rx_pkts);
			out_offset += snprintf(buf + out_offset, out_count - out_offset,
			"rx_memcpy - \t%llu\n", qp->rx_memcpy);
			out_offset += snprintf(buf + out_offset, out_count - out_offset,
			"rx_async - \t%llu\n", qp->rx_async);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,		out_offset += snprintf(buf + out_offset, out_count - out_offset,
	"rx_ring_empty - %llu\n", qp->rx_ring_empty);		"rx_ring_empty - %llu\n", qp->rx_ring_empty);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,		out_offset += snprintf(buf + out_offset, out_count - out_offset,
	@@ -414,8 +438,14 @@ static ssize_t debugfs_read(struct file filp, char __user ubuf, size_t count,
	"tx_bytes - \t%llu\n", qp->tx_bytes);		"tx_bytes - \t%llu\n", qp->tx_bytes);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,		out_offset += snprintf(buf + out_offset, out_count - out_offset,
	"tx_pkts - \t%llu\n", qp->tx_pkts);		"tx_pkts - \t%llu\n", qp->tx_pkts);
			out_offset += snprintf(buf + out_offset, out_count - out_offset,
			"tx_memcpy - \t%llu\n", qp->tx_memcpy);
			out_offset += snprintf(buf + out_offset, out_count - out_offset,
			"tx_async - \t%llu\n", qp->tx_async);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,		out_offset += snprintf(buf + out_offset, out_count - out_offset,
	"tx_ring_full - \t%llu\n", qp->tx_ring_full);		"tx_ring_full - \t%llu\n", qp->tx_ring_full);
			out_offset += snprintf(buf + out_offset, out_count - out_offset,
			"tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,		out_offset += snprintf(buf + out_offset, out_count - out_offset,
	"tx_mw - \t%p\n", qp->tx_mw);		"tx_mw - \t%p\n", qp->tx_mw);
	out_offset += snprintf(buf + out_offset, out_count - out_offset,		out_offset += snprintf(buf + out_offset, out_count - out_offset,
	@@ -488,11 +518,11 @@ static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
	num_qps_mw = nt->max_qps / mw_max;		num_qps_mw = nt->max_qps / mw_max;

	rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;		rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;
	qp->remote_rx_info = nt->mw[mw_num].virt_addr +		qp->rx_buff = nt->mw[mw_num].virt_addr + qp_num / mw_max * rx_size;
	(qp_num / mw_max * rx_size);
	rx_size -= sizeof(struct ntb_rx_info);		rx_size -= sizeof(struct ntb_rx_info);

	qp->rx_buff = qp->remote_rx_info + 1;		qp->remote_rx_info = qp->rx_buff + rx_size;

	/* Due to housekeeping, there must be atleast 2 buffs */		/* Due to housekeeping, there must be atleast 2 buffs */
	qp->rx_max_frame = min(transport_mtu, rx_size / 2);		qp->rx_max_frame = min(transport_mtu, rx_size / 2);
	qp->rx_max_entry = rx_size / qp->rx_max_frame;		qp->rx_max_entry = rx_size / qp->rx_max_frame;
	@@ -796,12 +826,13 @@ static void ntb_qp_link_work(struct work_struct *work)
	msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));		msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
	}		}

	static void ntb_transport_init_queue(struct ntb_transport *nt,		static int ntb_transport_init_queue(struct ntb_transport *nt,
	unsigned int qp_num)		unsigned int qp_num)
	{		{
	struct ntb_transport_qp *qp;		struct ntb_transport_qp *qp;
	unsigned int num_qps_mw, tx_size;		unsigned int num_qps_mw, tx_size;
	u8 mw_num, mw_max;		u8 mw_num, mw_max;
			u64 qp_offset;

	mw_max = ntb_max_mw(nt->ndev);		mw_max = ntb_max_mw(nt->ndev);
	mw_num = QP_TO_MW(nt->ndev, qp_num);		mw_num = QP_TO_MW(nt->ndev, qp_num);
	@@ -820,11 +851,18 @@ static void ntb_transport_init_queue(struct ntb_transport *nt,
	num_qps_mw = nt->max_qps / mw_max;		num_qps_mw = nt->max_qps / mw_max;

	tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;		tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
	qp->rx_info = ntb_get_mw_vbase(nt->ndev, mw_num) +		qp_offset = qp_num / mw_max * tx_size;
	(qp_num / mw_max * tx_size);		qp->tx_mw = ntb_get_mw_vbase(nt->ndev, mw_num) + qp_offset;
			if (!qp->tx_mw)
			return -EINVAL;

			qp->tx_mw_phys = ntb_get_mw_base(qp->ndev, mw_num) + qp_offset;
			if (!qp->tx_mw_phys)
			return -EINVAL;

	tx_size -= sizeof(struct ntb_rx_info);		tx_size -= sizeof(struct ntb_rx_info);
			qp->rx_info = qp->tx_mw + tx_size;

	qp->tx_mw = qp->rx_info + 1;
	/* Due to housekeeping, there must be atleast 2 buffs */		/* Due to housekeeping, there must be atleast 2 buffs */
	qp->tx_max_frame = min(transport_mtu, tx_size / 2);		qp->tx_max_frame = min(transport_mtu, tx_size / 2);
	qp->tx_max_entry = tx_size / qp->tx_max_frame;		qp->tx_max_entry = tx_size / qp->tx_max_frame;
	@@ -851,6 +889,8 @@ static void ntb_transport_init_queue(struct ntb_transport *nt,
	INIT_LIST_HEAD(&qp->rx_pend_q);		INIT_LIST_HEAD(&qp->rx_pend_q);
	INIT_LIST_HEAD(&qp->rx_free_q);		INIT_LIST_HEAD(&qp->rx_free_q);
	INIT_LIST_HEAD(&qp->tx_free_q);		INIT_LIST_HEAD(&qp->tx_free_q);

			return 0;
	}		}

	int ntb_transport_init(struct pci_dev *pdev)		int ntb_transport_init(struct pci_dev *pdev)
	@@ -889,8 +929,11 @@ int ntb_transport_init(struct pci_dev *pdev)

	nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;		nt->qp_bitmap = ((u64) 1 << nt->max_qps) - 1;

	for (i = 0; i < nt->max_qps; i++)		for (i = 0; i < nt->max_qps; i++) {
	ntb_transport_init_queue(nt, i);		rc = ntb_transport_init_queue(nt, i);
			if (rc)
			goto err3;
			}

	INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);		INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
	INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);		INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup);
	@@ -956,13 +999,19 @@ void ntb_transport_free(void *transport)
	kfree(nt);		kfree(nt);
	}		}

	static void ntb_rx_copy_task(struct ntb_transport_qp *qp,		static void ntb_rx_copy_callback(void *data)
	struct ntb_queue_entry entry, void offset)
	{		{
			struct ntb_queue_entry *entry = data;
			struct ntb_transport_qp *qp = entry->qp;
	void *cb_data = entry->cb_data;		void *cb_data = entry->cb_data;
	unsigned int len = entry->len;		unsigned int len = entry->len;
			struct ntb_payload_header *hdr = entry->rx_hdr;

	memcpy(entry->buf, offset, entry->len);		/* Ensure that the data is fully copied out before clearing the flag */
			wmb();
			hdr->flags = 0;

			iowrite32(entry->index, &qp->rx_info->entry);

	ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);		ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry, &qp->rx_free_q);

	@@ -970,6 +1019,86 @@ static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
	qp->rx_handler(qp, qp->cb_data, cb_data, len);		qp->rx_handler(qp, qp->cb_data, cb_data, len);
	}		}

			static void ntb_memcpy_rx(struct ntb_queue_entry entry, void offset)
			{
			void *buf = entry->buf;
			size_t len = entry->len;

			memcpy(buf, offset, len);

			ntb_rx_copy_callback(entry);
			}

			static void ntb_async_rx(struct ntb_queue_entry entry, void offset,
			size_t len)
			{
			struct dma_async_tx_descriptor *txd;
			struct ntb_transport_qp *qp = entry->qp;
			struct dma_chan *chan = qp->dma_chan;
			struct dma_device *device;
			size_t pay_off, buff_off;
			dma_addr_t src, dest;
			dma_cookie_t cookie;
			void *buf = entry->buf;
			unsigned long flags;

			entry->len = len;

			if (!chan)
			goto err;

			if (len < copy_bytes)
			goto err1;

			device = chan->device;
			pay_off = (size_t) offset & ~PAGE_MASK;
			buff_off = (size_t) buf & ~PAGE_MASK;

			if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
			goto err1;

			dest = dma_map_single(device->dev, buf, len, DMA_FROM_DEVICE);
			if (dma_mapping_error(device->dev, dest))
			goto err1;

			src = dma_map_single(device->dev, offset, len, DMA_TO_DEVICE);
			if (dma_mapping_error(device->dev, src))
			goto err2;

			flags = DMA_COMPL_DEST_UNMAP_SINGLE \| DMA_COMPL_SRC_UNMAP_SINGLE \|
			DMA_PREP_INTERRUPT;
			txd = device->device_prep_dma_memcpy(chan, dest, src, len, flags);
			if (!txd)
			goto err3;

			txd->callback = ntb_rx_copy_callback;
			txd->callback_param = entry;

			cookie = dmaengine_submit(txd);
			if (dma_submit_error(cookie))
			goto err3;

			qp->last_cookie = cookie;

			qp->rx_async++;

			return;

			err3:
			dma_unmap_single(device->dev, src, len, DMA_TO_DEVICE);
			err2:
			dma_unmap_single(device->dev, dest, len, DMA_FROM_DEVICE);
			err1:
			/* If the callbacks come out of order, the writing of the index to the
			* last completed will be out of order. This may result in the
			* receive stalling forever.
			*/
			dma_sync_wait(chan, qp->last_cookie);
			err:
			ntb_memcpy_rx(entry, offset);
			qp->rx_memcpy++;
			}

	static int ntb_process_rxc(struct ntb_transport_qp *qp)		static int ntb_process_rxc(struct ntb_transport_qp *qp)
	{		{
	struct ntb_payload_header *hdr;		struct ntb_payload_header *hdr;
	@@ -1008,41 +1137,45 @@ static int ntb_process_rxc(struct ntb_transport_qp *qp)
	if (hdr->flags & LINK_DOWN_FLAG) {		if (hdr->flags & LINK_DOWN_FLAG) {
	ntb_qp_link_down(qp);		ntb_qp_link_down(qp);

	ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,		goto err;
	&qp->rx_pend_q);
	goto out;
	}		}

	dev_dbg(&ntb_query_pdev(qp->ndev)->dev,		dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
	"rx offset %u, ver %u - %d payload received, buf size %d\n",		"rx offset %u, ver %u - %d payload received, buf size %d\n",
	qp->rx_index, hdr->ver, hdr->len, entry->len);		qp->rx_index, hdr->ver, hdr->len, entry->len);

	if (hdr->len <= entry->len) {		qp->rx_bytes += hdr->len;
	entry->len = hdr->len;		qp->rx_pkts++;
	ntb_rx_copy_task(qp, entry, offset);
	} else {
	ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
	&qp->rx_pend_q);

			if (hdr->len > entry->len) {
	qp->rx_err_oflow++;		qp->rx_err_oflow++;
	dev_dbg(&ntb_query_pdev(qp->ndev)->dev,		dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
	"RX overflow! Wanted %d got %d\n",		"RX overflow! Wanted %d got %d\n",
	hdr->len, entry->len);		hdr->len, entry->len);

			goto err;
	}		}

	qp->rx_bytes += hdr->len;		entry->index = qp->rx_index;
	qp->rx_pkts++;		entry->rx_hdr = hdr;

			ntb_async_rx(entry, offset, hdr->len);

	out:		out:
			qp->rx_index++;
			qp->rx_index %= qp->rx_max_entry;

			return 0;

			err:
			ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
			&qp->rx_pend_q);
	/* Ensure that the data is fully copied out before clearing the flag */		/* Ensure that the data is fully copied out before clearing the flag */
	wmb();		wmb();
	hdr->flags = 0;		hdr->flags = 0;
	iowrite32(qp->rx_index, &qp->rx_info->entry);		iowrite32(qp->rx_index, &qp->rx_info->entry);

	qp->rx_index++;		goto out;
	qp->rx_index %= qp->rx_max_entry;

	return 0;
	}		}

	static void ntb_transport_rx(unsigned long data)		static void ntb_transport_rx(unsigned long data)
	@@ -1058,6 +1191,9 @@ static void ntb_transport_rx(unsigned long data)
	if (rc)		if (rc)
	break;		break;
	}		}

			if (qp->dma_chan)
			dma_async_issue_pending(qp->dma_chan);
	}		}

	static void ntb_transport_rxc_db(void *data, int db_num)		static void ntb_transport_rxc_db(void *data, int db_num)
	@@ -1070,19 +1206,13 @@ static void ntb_transport_rxc_db(void *data, int db_num)
	tasklet_schedule(&qp->rx_work);		tasklet_schedule(&qp->rx_work);
	}		}

	static void ntb_tx_copy_task(struct ntb_transport_qp *qp,		static void ntb_tx_copy_callback(void *data)
	struct ntb_queue_entry *entry,
	void __iomem *offset)
	{		{
	struct ntb_payload_header __iomem *hdr;		struct ntb_queue_entry *entry = data;
			struct ntb_transport_qp *qp = entry->qp;
	memcpy_toio(offset, entry->buf, entry->len);		struct ntb_payload_header __iomem *hdr = entry->tx_hdr;

	hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);		/* Ensure that the data is fully copied out before setting the flags */
	iowrite32(entry->len, &hdr->len);
	iowrite32((u32) qp->tx_pkts, &hdr->ver);

	/* Ensure that the data is fully copied out before setting the flag */
	wmb();		wmb();
	iowrite32(entry->flags \| DESC_DONE_FLAG, &hdr->flags);		iowrite32(entry->flags \| DESC_DONE_FLAG, &hdr->flags);

	@@ -1103,15 +1233,81 @@ static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
	ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);		ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
	}		}

	static int ntb_process_tx(struct ntb_transport_qp *qp,		static void ntb_memcpy_tx(struct ntb_queue_entry entry, void __iomem offset)
			{
			memcpy_toio(offset, entry->buf, entry->len);

			ntb_tx_copy_callback(entry);
			}

			static void ntb_async_tx(struct ntb_transport_qp *qp,
	struct ntb_queue_entry *entry)		struct ntb_queue_entry *entry)
	{		{
			struct ntb_payload_header __iomem *hdr;
			struct dma_async_tx_descriptor *txd;
			struct dma_chan *chan = qp->dma_chan;
			struct dma_device *device;
			size_t dest_off, buff_off;
			dma_addr_t src, dest;
			dma_cookie_t cookie;
	void __iomem *offset;		void __iomem *offset;
			size_t len = entry->len;
			void *buf = entry->buf;
			unsigned long flags;

	offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;		offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
			hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
			entry->tx_hdr = hdr;

			iowrite32(entry->len, &hdr->len);
			iowrite32((u32) qp->tx_pkts, &hdr->ver);

			if (!chan)
			goto err;

	dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %u, entry len %d flags %x buff %p\n",		if (len < copy_bytes)
	qp->tx_pkts, offset, qp->tx_index, entry->len, entry->flags,		goto err;

			device = chan->device;
			dest = qp->tx_mw_phys + qp->tx_max_frame * qp->tx_index;
			buff_off = (size_t) buf & ~PAGE_MASK;
			dest_off = (size_t) dest & ~PAGE_MASK;

			if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
			goto err;

			src = dma_map_single(device->dev, buf, len, DMA_TO_DEVICE);
			if (dma_mapping_error(device->dev, src))
			goto err;

			flags = DMA_COMPL_SRC_UNMAP_SINGLE \| DMA_PREP_INTERRUPT;
			txd = device->device_prep_dma_memcpy(chan, dest, src, len, flags);
			if (!txd)
			goto err1;

			txd->callback = ntb_tx_copy_callback;
			txd->callback_param = entry;

			cookie = dmaengine_submit(txd);
			if (dma_submit_error(cookie))
			goto err1;

			dma_async_issue_pending(chan);
			qp->tx_async++;

			return;
			err1:
			dma_unmap_single(device->dev, src, len, DMA_TO_DEVICE);
			err:
			ntb_memcpy_tx(entry, offset);
			qp->tx_memcpy++;
			}

			static int ntb_process_tx(struct ntb_transport_qp *qp,
			struct ntb_queue_entry *entry)
			{
			dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - tx %u, entry len %d flags %x buff %p\n",
			qp->tx_pkts, qp->tx_index, entry->len, entry->flags,
	entry->buf);		entry->buf);
	if (qp->tx_index == qp->remote_rx_info->entry) {		if (qp->tx_index == qp->remote_rx_info->entry) {
	qp->tx_ring_full++;		qp->tx_ring_full++;
	@@ -1127,7 +1323,7 @@ static int ntb_process_tx(struct ntb_transport_qp *qp,
	return 0;		return 0;
	}		}

	ntb_tx_copy_task(qp, entry, offset);		ntb_async_tx(qp, entry);

	qp->tx_index++;		qp->tx_index++;
	qp->tx_index %= qp->tx_max_entry;		qp->tx_index %= qp->tx_max_entry;
	@@ -1213,11 +1409,18 @@ ntb_transport_create_queue(void data, struct pci_dev pdev,
	qp->tx_handler = handlers->tx_handler;		qp->tx_handler = handlers->tx_handler;
	qp->event_handler = handlers->event_handler;		qp->event_handler = handlers->event_handler;

			qp->dma_chan = dma_find_channel(DMA_MEMCPY);
			if (!qp->dma_chan)
			dev_info(&pdev->dev, "Unable to allocate DMA channel, using CPU instead\n");
			else
			dmaengine_get();

	for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {		for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
	entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);		entry = kzalloc(sizeof(struct ntb_queue_entry), GFP_ATOMIC);
	if (!entry)		if (!entry)
	goto err1;		goto err1;

			entry->qp = qp;
	ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,		ntb_list_add(&qp->ntb_rx_free_q_lock, &entry->entry,
	&qp->rx_free_q);		&qp->rx_free_q);
	}		}
	@@ -1227,6 +1430,7 @@ ntb_transport_create_queue(void data, struct pci_dev pdev,
	if (!entry)		if (!entry)
	goto err2;		goto err2;

			entry->qp = qp;
	ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,		ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
	&qp->tx_free_q);		&qp->tx_free_q);
	}		}
	@@ -1272,11 +1476,26 @@ void ntb_transport_free_queue(struct ntb_transport_qp *qp)

	pdev = ntb_query_pdev(qp->ndev);		pdev = ntb_query_pdev(qp->ndev);

	cancel_delayed_work_sync(&qp->link_work);		if (qp->dma_chan) {
			struct dma_chan *chan = qp->dma_chan;
			/* Putting the dma_chan to NULL will force any new traffic to be
			* processed by the CPU instead of the DAM engine
			*/
			qp->dma_chan = NULL;

			/* Try to be nice and wait for any queued DMA engine
			* transactions to process before smashing it with a rock
			*/
			dma_sync_wait(chan, qp->last_cookie);
			dmaengine_terminate_all(chan);
			dmaengine_put();
			}

	ntb_unregister_db_callback(qp->ndev, qp->qp_num);		ntb_unregister_db_callback(qp->ndev, qp->qp_num);
	tasklet_disable(&qp->rx_work);		tasklet_disable(&qp->rx_work);

			cancel_delayed_work_sync(&qp->link_work);

	while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))		while ((entry = ntb_list_rm(&qp->ntb_rx_free_q_lock, &qp->rx_free_q)))
	kfree(entry);		kfree(entry);

	@@ -1382,8 +1601,10 @@ int ntb_transport_tx_enqueue(struct ntb_transport_qp qp, void cb, void *data,
	return -EINVAL;		return -EINVAL;

	entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);		entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
	if (!entry)		if (!entry) {
			qp->tx_err_no_buf++;
	return -ENOMEM;		return -ENOMEM;
			}

	entry->cb_data = cb;		entry->cb_data = cb;
	entry->buf = data;		entry->buf = data;
	@@ -1499,9 +1720,18 @@ EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
	*/		*/
	unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)		unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
	{		{
			unsigned int max;

	if (!qp)		if (!qp)
	return 0;		return 0;

			if (!qp->dma_chan)
	return qp->tx_max_frame - sizeof(struct ntb_payload_header);		return qp->tx_max_frame - sizeof(struct ntb_payload_header);

			/* If DMA engine usage is possible, try to find the max size for that */
			max = qp->tx_max_frame - sizeof(struct ntb_payload_header);
			max -= max % (1 << qp->dma_chan->device->copy_align);

			return max;
	}		}
	EXPORT_SYMBOL_GPL(ntb_transport_max_size);		EXPORT_SYMBOL_GPL(ntb_transport_max_size);