Merge branch 'tip/perf/jump-label-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent

1 files changed, 965 insertions, 0 deletions

diff --git a/drivers/net/davinci_cpdma.c b/drivers/net/davinci_cpdma.c
new file mode 100644
index 000000000000..e92b2b6cd8c4
--- /dev/null
+++ b/drivers/net/davinci_cpdma.c
@@ -0,0 +1,965 @@
+/*
+ * Texas Instruments CPDMA Driver
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+
+#include "davinci_cpdma.h"
+
+/* DMA Registers */
+#define CPDMA_TXIDVER		0x00
+#define CPDMA_TXCONTROL		0x04
+#define CPDMA_TXTEARDOWN	0x08
+#define CPDMA_RXIDVER		0x10
+#define CPDMA_RXCONTROL		0x14
+#define CPDMA_SOFTRESET		0x1c
+#define CPDMA_RXTEARDOWN	0x18
+#define CPDMA_TXINTSTATRAW	0x80
+#define CPDMA_TXINTSTATMASKED	0x84
+#define CPDMA_TXINTMASKSET	0x88
+#define CPDMA_TXINTMASKCLEAR	0x8c
+#define CPDMA_MACINVECTOR	0x90
+#define CPDMA_MACEOIVECTOR	0x94
+#define CPDMA_RXINTSTATRAW	0xa0
+#define CPDMA_RXINTSTATMASKED	0xa4
+#define CPDMA_RXINTMASKSET	0xa8
+#define CPDMA_RXINTMASKCLEAR	0xac
+#define CPDMA_DMAINTSTATRAW	0xb0
+#define CPDMA_DMAINTSTATMASKED	0xb4
+#define CPDMA_DMAINTMASKSET	0xb8
+#define CPDMA_DMAINTMASKCLEAR	0xbc
+#define CPDMA_DMAINT_HOSTERR	BIT(1)
+
+/* the following exist only if has_ext_regs is set */
+#define CPDMA_DMACONTROL	0x20
+#define CPDMA_DMASTATUS		0x24
+#define CPDMA_RXBUFFOFS		0x28
+#define CPDMA_EM_CONTROL	0x2c
+
+/* Descriptor mode bits */
+#define CPDMA_DESC_SOP		BIT(31)
+#define CPDMA_DESC_EOP		BIT(30)
+#define CPDMA_DESC_OWNER	BIT(29)
+#define CPDMA_DESC_EOQ		BIT(28)
+#define CPDMA_DESC_TD_COMPLETE	BIT(27)
+#define CPDMA_DESC_PASS_CRC	BIT(26)
+
+#define CPDMA_TEARDOWN_VALUE	0xfffffffc
+
+struct cpdma_desc {
+	/* hardware fields */
+	u32			hw_next;
+	u32			hw_buffer;
+	u32			hw_len;
+	u32			hw_mode;
+	/* software fields */
+	void			*sw_token;
+	u32			sw_buffer;
+	u32			sw_len;
+};
+
+struct cpdma_desc_pool {
+	u32			phys;
+	void __iomem		*iomap;		/* ioremap map */
+	void			*cpumap;	/* dma_alloc map */
+	int			desc_size, mem_size;
+	int			num_desc, used_desc;
+	unsigned long		*bitmap;
+	struct device		*dev;
+	spinlock_t		lock;
+};
+
+enum cpdma_state {
+	CPDMA_STATE_IDLE,
+	CPDMA_STATE_ACTIVE,
+	CPDMA_STATE_TEARDOWN,
+};
+
+const char *cpdma_state_str[] = { "idle", "active", "teardown" };
+
+struct cpdma_ctlr {
+	enum cpdma_state	state;
+	struct cpdma_params	params;
+	struct device		*dev;
+	struct cpdma_desc_pool	*pool;
+	spinlock_t		lock;
+	struct cpdma_chan	*channels[2 * CPDMA_MAX_CHANNELS];
+};
+
+struct cpdma_chan {
+	enum cpdma_state		state;
+	struct cpdma_ctlr		*ctlr;
+	int				chan_num;
+	spinlock_t			lock;
+	struct cpdma_desc __iomem	*head, *tail;
+	int				count;
+	void __iomem			*hdp, *cp, *rxfree;
+	u32				mask;
+	cpdma_handler_fn		handler;
+	enum dma_data_direction		dir;
+	struct cpdma_chan_stats		stats;
+	/* offsets into dmaregs */
+	int	int_set, int_clear, td;
+};
+
+/* The following make access to common cpdma_ctlr params more readable */
+#define dmaregs		params.dmaregs
+#define num_chan	params.num_chan
+
+/* various accessors */
+#define dma_reg_read(ctlr, ofs)		__raw_readl((ctlr)->dmaregs + (ofs))
+#define chan_read(chan, fld)		__raw_readl((chan)->fld)
+#define desc_read(desc, fld)		__raw_readl(&(desc)->fld)
+#define dma_reg_write(ctlr, ofs, v)	__raw_writel(v, (ctlr)->dmaregs + (ofs))
+#define chan_write(chan, fld, v)	__raw_writel(v, (chan)->fld)
+#define desc_write(desc, fld, v)	__raw_writel((u32)(v), &(desc)->fld)
+
+/*
+ * Utility constructs for a cpdma descriptor pool.  Some devices (e.g. davinci
+ * emac) have dedicated on-chip memory for these descriptors.  Some other
+ * devices (e.g. cpsw switches) use plain old memory.  Descriptor pools
+ * abstract out these details
+ */
+static struct cpdma_desc_pool *
+cpdma_desc_pool_create(struct device *dev, u32 phys, int size, int align)
+{
+	int bitmap_size;
+	struct cpdma_desc_pool *pool;
+
+	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
+	if (!pool)
+		return NULL;
+
+	spin_lock_init(&pool->lock);
+
+	pool->dev	= dev;
+	pool->mem_size	= size;
+	pool->desc_size	= ALIGN(sizeof(struct cpdma_desc), align);
+	pool->num_desc	= size / pool->desc_size;
+
+	bitmap_size  = (pool->num_desc / BITS_PER_LONG) * sizeof(long);
+	pool->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+	if (!pool->bitmap)
+		goto fail;
+
+	if (phys) {
+		pool->phys  = phys;
+		pool->iomap = ioremap(phys, size);
+	} else {
+		pool->cpumap = dma_alloc_coherent(dev, size, &pool->phys,
+						  GFP_KERNEL);
+		pool->iomap = (void __force __iomem *)pool->cpumap;
+	}
+
+	if (pool->iomap)
+		return pool;
+
+fail:
+	kfree(pool->bitmap);
+	kfree(pool);
+	return NULL;
+}
+
+static void cpdma_desc_pool_destroy(struct cpdma_desc_pool *pool)
+{
+	unsigned long flags;
+
+	if (!pool)
+		return;
+
+	spin_lock_irqsave(&pool->lock, flags);
+	WARN_ON(pool->used_desc);
+	kfree(pool->bitmap);
+	if (pool->cpumap) {
+		dma_free_coherent(pool->dev, pool->mem_size, pool->cpumap,
+				  pool->phys);
+	} else {
+		iounmap(pool->iomap);
+	}
+	spin_unlock_irqrestore(&pool->lock, flags);
+	kfree(pool);
+}
+
+static inline dma_addr_t desc_phys(struct cpdma_desc_pool *pool,
+		  struct cpdma_desc __iomem *desc)
+{
+	if (!desc)
+		return 0;
+	return pool->phys + (__force dma_addr_t)desc -
+			    (__force dma_addr_t)pool->iomap;
+}
+
+static inline struct cpdma_desc __iomem *
+desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma)
+{
+	return dma ? pool->iomap + dma - pool->phys : NULL;
+}
+
+static struct cpdma_desc __iomem *
+cpdma_desc_alloc(struct cpdma_desc_pool *pool, int num_desc)
+{
+	unsigned long flags;
+	int index;
+	struct cpdma_desc __iomem *desc = NULL;
+
+	spin_lock_irqsave(&pool->lock, flags);
+
+	index = bitmap_find_next_zero_area(pool->bitmap, pool->num_desc, 0,
+					   num_desc, 0);
+	if (index < pool->num_desc) {
+		bitmap_set(pool->bitmap, index, num_desc);
+		desc = pool->iomap + pool->desc_size * index;
+		pool->used_desc++;
+	}
+
+	spin_unlock_irqrestore(&pool->lock, flags);
+	return desc;
+}
+
+static void cpdma_desc_free(struct cpdma_desc_pool *pool,
+			    struct cpdma_desc __iomem *desc, int num_desc)
+{
+	unsigned long flags, index;
+
+	index = ((unsigned long)desc - (unsigned long)pool->iomap) /
+		pool->desc_size;
+	spin_lock_irqsave(&pool->lock, flags);
+	bitmap_clear(pool->bitmap, index, num_desc);
+	pool->used_desc--;
+	spin_unlock_irqrestore(&pool->lock, flags);
+}
+
+struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params)
+{
+	struct cpdma_ctlr *ctlr;
+
+	ctlr = kzalloc(sizeof(*ctlr), GFP_KERNEL);
+	if (!ctlr)
+		return NULL;
+
+	ctlr->state = CPDMA_STATE_IDLE;
+	ctlr->params = *params;
+	ctlr->dev = params->dev;
+	spin_lock_init(&ctlr->lock);
+
+	ctlr->pool = cpdma_desc_pool_create(ctlr->dev,
+					    ctlr->params.desc_mem_phys,
+					    ctlr->params.desc_mem_size,
+					    ctlr->params.desc_align);
+	if (!ctlr->pool) {
+		kfree(ctlr);
+		return NULL;
+	}
+
+	if (WARN_ON(ctlr->num_chan > CPDMA_MAX_CHANNELS))
+		ctlr->num_chan = CPDMA_MAX_CHANNELS;
+	return ctlr;
+}
+
+int cpdma_ctlr_start(struct cpdma_ctlr *ctlr)
+{
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+	if (ctlr->state != CPDMA_STATE_IDLE) {
+		spin_unlock_irqrestore(&ctlr->lock, flags);
+		return -EBUSY;
+	}
+
+	if (ctlr->params.has_soft_reset) {
+		unsigned long timeout = jiffies + HZ/10;
+
+		dma_reg_write(ctlr, CPDMA_SOFTRESET, 1);
+		while (time_before(jiffies, timeout)) {
+			if (dma_reg_read(ctlr, CPDMA_SOFTRESET) == 0)
+				break;
+		}
+		WARN_ON(!time_before(jiffies, timeout));
+	}
+
+	for (i = 0; i < ctlr->num_chan; i++) {
+		__raw_writel(0, ctlr->params.txhdp + 4 * i);
+		__raw_writel(0, ctlr->params.rxhdp + 4 * i);
+		__raw_writel(0, ctlr->params.txcp + 4 * i);
+		__raw_writel(0, ctlr->params.rxcp + 4 * i);
+	}
+
+	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
+	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
+
+	dma_reg_write(ctlr, CPDMA_TXCONTROL, 1);
+	dma_reg_write(ctlr, CPDMA_RXCONTROL, 1);
+
+	ctlr->state = CPDMA_STATE_ACTIVE;
+
+	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
+		if (ctlr->channels[i])
+			cpdma_chan_start(ctlr->channels[i]);
+	}
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+	return 0;
+}
+
+int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
+{
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+	if (ctlr->state != CPDMA_STATE_ACTIVE) {
+		spin_unlock_irqrestore(&ctlr->lock, flags);
+		return -EINVAL;
+	}
+
+	ctlr->state = CPDMA_STATE_TEARDOWN;
+
+	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
+		if (ctlr->channels[i])
+			cpdma_chan_stop(ctlr->channels[i]);
+	}
+
+	dma_reg_write(ctlr, CPDMA_RXINTMASKCLEAR, 0xffffffff);
+	dma_reg_write(ctlr, CPDMA_TXINTMASKCLEAR, 0xffffffff);
+
+	dma_reg_write(ctlr, CPDMA_TXCONTROL, 0);
+	dma_reg_write(ctlr, CPDMA_RXCONTROL, 0);
+
+	ctlr->state = CPDMA_STATE_IDLE;
+
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+	return 0;
+}
+
+int cpdma_ctlr_dump(struct cpdma_ctlr *ctlr)
+{
+	struct device *dev = ctlr->dev;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+
+	dev_info(dev, "CPDMA: state: %s", cpdma_state_str[ctlr->state]);
+
+	dev_info(dev, "CPDMA: txidver: %x",
+		 dma_reg_read(ctlr, CPDMA_TXIDVER));
+	dev_info(dev, "CPDMA: txcontrol: %x",
+		 dma_reg_read(ctlr, CPDMA_TXCONTROL));
+	dev_info(dev, "CPDMA: txteardown: %x",
+		 dma_reg_read(ctlr, CPDMA_TXTEARDOWN));
+	dev_info(dev, "CPDMA: rxidver: %x",
+		 dma_reg_read(ctlr, CPDMA_RXIDVER));
+	dev_info(dev, "CPDMA: rxcontrol: %x",
+		 dma_reg_read(ctlr, CPDMA_RXCONTROL));
+	dev_info(dev, "CPDMA: softreset: %x",
+		 dma_reg_read(ctlr, CPDMA_SOFTRESET));
+	dev_info(dev, "CPDMA: rxteardown: %x",
+		 dma_reg_read(ctlr, CPDMA_RXTEARDOWN));
+	dev_info(dev, "CPDMA: txintstatraw: %x",
+		 dma_reg_read(ctlr, CPDMA_TXINTSTATRAW));
+	dev_info(dev, "CPDMA: txintstatmasked: %x",
+		 dma_reg_read(ctlr, CPDMA_TXINTSTATMASKED));
+	dev_info(dev, "CPDMA: txintmaskset: %x",
+		 dma_reg_read(ctlr, CPDMA_TXINTMASKSET));
+	dev_info(dev, "CPDMA: txintmaskclear: %x",
+		 dma_reg_read(ctlr, CPDMA_TXINTMASKCLEAR));
+	dev_info(dev, "CPDMA: macinvector: %x",
+		 dma_reg_read(ctlr, CPDMA_MACINVECTOR));
+	dev_info(dev, "CPDMA: maceoivector: %x",
+		 dma_reg_read(ctlr, CPDMA_MACEOIVECTOR));
+	dev_info(dev, "CPDMA: rxintstatraw: %x",
+		 dma_reg_read(ctlr, CPDMA_RXINTSTATRAW));
+	dev_info(dev, "CPDMA: rxintstatmasked: %x",
+		 dma_reg_read(ctlr, CPDMA_RXINTSTATMASKED));
+	dev_info(dev, "CPDMA: rxintmaskset: %x",
+		 dma_reg_read(ctlr, CPDMA_RXINTMASKSET));
+	dev_info(dev, "CPDMA: rxintmaskclear: %x",
+		 dma_reg_read(ctlr, CPDMA_RXINTMASKCLEAR));
+	dev_info(dev, "CPDMA: dmaintstatraw: %x",
+		 dma_reg_read(ctlr, CPDMA_DMAINTSTATRAW));
+	dev_info(dev, "CPDMA: dmaintstatmasked: %x",
+		 dma_reg_read(ctlr, CPDMA_DMAINTSTATMASKED));
+	dev_info(dev, "CPDMA: dmaintmaskset: %x",
+		 dma_reg_read(ctlr, CPDMA_DMAINTMASKSET));
+	dev_info(dev, "CPDMA: dmaintmaskclear: %x",
+		 dma_reg_read(ctlr, CPDMA_DMAINTMASKCLEAR));
+
+	if (!ctlr->params.has_ext_regs) {
+		dev_info(dev, "CPDMA: dmacontrol: %x",
+			 dma_reg_read(ctlr, CPDMA_DMACONTROL));
+		dev_info(dev, "CPDMA: dmastatus: %x",
+			 dma_reg_read(ctlr, CPDMA_DMASTATUS));
+		dev_info(dev, "CPDMA: rxbuffofs: %x",
+			 dma_reg_read(ctlr, CPDMA_RXBUFFOFS));
+	}
+
+	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++)
+		if (ctlr->channels[i])
+			cpdma_chan_dump(ctlr->channels[i]);
+
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+	return 0;
+}
+
+int cpdma_ctlr_destroy(struct cpdma_ctlr *ctlr)
+{
+	unsigned long flags;
+	int ret = 0, i;
+
+	if (!ctlr)
+		return -EINVAL;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+	if (ctlr->state != CPDMA_STATE_IDLE)
+		cpdma_ctlr_stop(ctlr);
+
+	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
+		if (ctlr->channels[i])
+			cpdma_chan_destroy(ctlr->channels[i]);
+	}
+
+	cpdma_desc_pool_destroy(ctlr->pool);
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+	kfree(ctlr);
+	return ret;
+}
+
+int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
+{
+	unsigned long flags;
+	int i, reg;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+	if (ctlr->state != CPDMA_STATE_ACTIVE) {
+		spin_unlock_irqrestore(&ctlr->lock, flags);
+		return -EINVAL;
+	}
+
+	reg = enable ? CPDMA_DMAINTMASKSET : CPDMA_DMAINTMASKCLEAR;
+	dma_reg_write(ctlr, reg, CPDMA_DMAINT_HOSTERR);
+
+	for (i = 0; i < ARRAY_SIZE(ctlr->channels); i++) {
+		if (ctlr->channels[i])
+			cpdma_chan_int_ctrl(ctlr->channels[i], enable);
+	}
+
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+	return 0;
+}
+
+void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr)
+{
+	dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, 0);
+}
+
+struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
+				     cpdma_handler_fn handler)
+{
+	struct cpdma_chan *chan;
+	int ret, offset = (chan_num % CPDMA_MAX_CHANNELS) * 4;
+	unsigned long flags;
+
+	if (__chan_linear(chan_num) >= ctlr->num_chan)
+		return NULL;
+
+	ret = -ENOMEM;
+	chan = kzalloc(sizeof(*chan), GFP_KERNEL);
+	if (!chan)
+		goto err_chan_alloc;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+	ret = -EBUSY;
+	if (ctlr->channels[chan_num])
+		goto err_chan_busy;
+
+	chan->ctlr	= ctlr;
+	chan->state	= CPDMA_STATE_IDLE;
+	chan->chan_num	= chan_num;
+	chan->handler	= handler;
+
+	if (is_rx_chan(chan)) {
+		chan->hdp	= ctlr->params.rxhdp + offset;
+		chan->cp	= ctlr->params.rxcp + offset;
+		chan->rxfree	= ctlr->params.rxfree + offset;
+		chan->int_set	= CPDMA_RXINTMASKSET;
+		chan->int_clear	= CPDMA_RXINTMASKCLEAR;
+		chan->td	= CPDMA_RXTEARDOWN;
+		chan->dir	= DMA_FROM_DEVICE;
+	} else {
+		chan->hdp	= ctlr->params.txhdp + offset;
+		chan->cp	= ctlr->params.txcp + offset;
+		chan->int_set	= CPDMA_TXINTMASKSET;
+		chan->int_clear	= CPDMA_TXINTMASKCLEAR;
+		chan->td	= CPDMA_TXTEARDOWN;
+		chan->dir	= DMA_TO_DEVICE;
+	}
+	chan->mask = BIT(chan_linear(chan));
+
+	spin_lock_init(&chan->lock);
+
+	ctlr->channels[chan_num] = chan;
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+	return chan;
+
+err_chan_busy:
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+	kfree(chan);
+err_chan_alloc:
+	return ERR_PTR(ret);
+}
+
+int cpdma_chan_destroy(struct cpdma_chan *chan)
+{
+	struct cpdma_ctlr *ctlr = chan->ctlr;
+	unsigned long flags;
+
+	if (!chan)
+		return -EINVAL;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+	if (chan->state != CPDMA_STATE_IDLE)
+		cpdma_chan_stop(chan);
+	ctlr->channels[chan->chan_num] = NULL;
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+	kfree(chan);
+	return 0;
+}
+
+int cpdma_chan_get_stats(struct cpdma_chan *chan,
+			 struct cpdma_chan_stats *stats)
+{
+	unsigned long flags;
+	if (!chan)
+		return -EINVAL;
+	spin_lock_irqsave(&chan->lock, flags);
+	memcpy(stats, &chan->stats, sizeof(*stats));
+	spin_unlock_irqrestore(&chan->lock, flags);
+	return 0;
+}
+
+int cpdma_chan_dump(struct cpdma_chan *chan)
+{
+	unsigned long flags;
+	struct device *dev = chan->ctlr->dev;
+
+	spin_lock_irqsave(&chan->lock, flags);
+
+	dev_info(dev, "channel %d (%s %d) state %s",
+		 chan->chan_num, is_rx_chan(chan) ? "rx" : "tx",
+		 chan_linear(chan), cpdma_state_str[chan->state]);
+	dev_info(dev, "\thdp: %x\n", chan_read(chan, hdp));
+	dev_info(dev, "\tcp: %x\n", chan_read(chan, cp));
+	if (chan->rxfree) {
+		dev_info(dev, "\trxfree: %x\n",
+			 chan_read(chan, rxfree));
+	}
+
+	dev_info(dev, "\tstats head_enqueue: %d\n",
+		 chan->stats.head_enqueue);
+	dev_info(dev, "\tstats tail_enqueue: %d\n",
+		 chan->stats.tail_enqueue);
+	dev_info(dev, "\tstats pad_enqueue: %d\n",
+		 chan->stats.pad_enqueue);
+	dev_info(dev, "\tstats misqueued: %d\n",
+		 chan->stats.misqueued);
+	dev_info(dev, "\tstats desc_alloc_fail: %d\n",
+		 chan->stats.desc_alloc_fail);
+	dev_info(dev, "\tstats pad_alloc_fail: %d\n",
+		 chan->stats.pad_alloc_fail);
+	dev_info(dev, "\tstats runt_receive_buff: %d\n",
+		 chan->stats.runt_receive_buff);
+	dev_info(dev, "\tstats runt_transmit_buff: %d\n",
+		 chan->stats.runt_transmit_buff);
+	dev_info(dev, "\tstats empty_dequeue: %d\n",
+		 chan->stats.empty_dequeue);
+	dev_info(dev, "\tstats busy_dequeue: %d\n",
+		 chan->stats.busy_dequeue);
+	dev_info(dev, "\tstats good_dequeue: %d\n",
+		 chan->stats.good_dequeue);
+	dev_info(dev, "\tstats requeue: %d\n",
+		 chan->stats.requeue);
+	dev_info(dev, "\tstats teardown_dequeue: %d\n",
+		 chan->stats.teardown_dequeue);
+
+	spin_unlock_irqrestore(&chan->lock, flags);
+	return 0;
+}
+
+static void __cpdma_chan_submit(struct cpdma_chan *chan,
+				struct cpdma_desc __iomem *desc)
+{
+	struct cpdma_ctlr		*ctlr = chan->ctlr;
+	struct cpdma_desc __iomem	*prev = chan->tail;
+	struct cpdma_desc_pool		*pool = ctlr->pool;
+	dma_addr_t			desc_dma;
+	u32				mode;
+
+	desc_dma = desc_phys(pool, desc);
+
+	/* simple case - idle channel */
+	if (!chan->head) {
+		chan->stats.head_enqueue++;
+		chan->head = desc;
+		chan->tail = desc;
+		if (chan->state == CPDMA_STATE_ACTIVE)
+			chan_write(chan, hdp, desc_dma);
+		return;
+	}
+
+	/* first chain the descriptor at the tail of the list */
+	desc_write(prev, hw_next, desc_dma);
+	chan->tail = desc;
+	chan->stats.tail_enqueue++;
+
+	/* next check if EOQ has been triggered already */
+	mode = desc_read(prev, hw_mode);
+	if (((mode & (CPDMA_DESC_EOQ | CPDMA_DESC_OWNER)) == CPDMA_DESC_EOQ) &&
+	    (chan->state == CPDMA_STATE_ACTIVE)) {
+		desc_write(prev, hw_mode, mode & ~CPDMA_DESC_EOQ);
+		chan_write(chan, hdp, desc_dma);
+		chan->stats.misqueued++;
+	}
+}
+
+int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
+		      int len, gfp_t gfp_mask)
+{
+	struct cpdma_ctlr		*ctlr = chan->ctlr;
+	struct cpdma_desc __iomem	*desc;
+	dma_addr_t			buffer;
+	unsigned long			flags;
+	u32				mode;
+	int				ret = 0;
+
+	spin_lock_irqsave(&chan->lock, flags);
+
+	if (chan->state == CPDMA_STATE_TEARDOWN) {
+		ret = -EINVAL;
+		goto unlock_ret;
+	}
+
+	desc = cpdma_desc_alloc(ctlr->pool, 1);
+	if (!desc) {
+		chan->stats.desc_alloc_fail++;
+		ret = -ENOMEM;
+		goto unlock_ret;
+	}
+
+	if (len < ctlr->params.min_packet_size) {
+		len = ctlr->params.min_packet_size;
+		chan->stats.runt_transmit_buff++;
+	}
+
+	buffer = dma_map_single(ctlr->dev, data, len, chan->dir);
+	mode = CPDMA_DESC_OWNER | CPDMA_DESC_SOP | CPDMA_DESC_EOP;
+
+	desc_write(desc, hw_next,   0);
+	desc_write(desc, hw_buffer, buffer);
+	desc_write(desc, hw_len,    len);
+	desc_write(desc, hw_mode,   mode | len);
+	desc_write(desc, sw_token,  token);
+	desc_write(desc, sw_buffer, buffer);
+	desc_write(desc, sw_len,    len);
+
+	__cpdma_chan_submit(chan, desc);
+
+	if (chan->state == CPDMA_STATE_ACTIVE && chan->rxfree)
+		chan_write(chan, rxfree, 1);
+
+	chan->count++;
+
+unlock_ret:
+	spin_unlock_irqrestore(&chan->lock, flags);
+	return ret;
+}
+
+static void __cpdma_chan_free(struct cpdma_chan *chan,
+			      struct cpdma_desc __iomem *desc,
+			      int outlen, int status)
+{
+	struct cpdma_ctlr		*ctlr = chan->ctlr;
+	struct cpdma_desc_pool		*pool = ctlr->pool;
+	dma_addr_t			buff_dma;
+	int				origlen;
+	void				*token;
+
+	token      = (void *)desc_read(desc, sw_token);
+	buff_dma   = desc_read(desc, sw_buffer);
+	origlen    = desc_read(desc, sw_len);
+
+	dma_unmap_single(ctlr->dev, buff_dma, origlen, chan->dir);
+	cpdma_desc_free(pool, desc, 1);
+	(*chan->handler)(token, outlen, status);
+}
+
+static int __cpdma_chan_process(struct cpdma_chan *chan)
+{
+	struct cpdma_ctlr		*ctlr = chan->ctlr;
+	struct cpdma_desc __iomem	*desc;
+	int				status, outlen;
+	struct cpdma_desc_pool		*pool = ctlr->pool;
+	dma_addr_t			desc_dma;
+	unsigned long			flags;
+
+	spin_lock_irqsave(&chan->lock, flags);
+
+	desc = chan->head;
+	if (!desc) {
+		chan->stats.empty_dequeue++;
+		status = -ENOENT;
+		goto unlock_ret;
+	}
+	desc_dma = desc_phys(pool, desc);
+
+	status	= __raw_readl(&desc->hw_mode);
+	outlen	= status & 0x7ff;
+	if (status & CPDMA_DESC_OWNER) {
+		chan->stats.busy_dequeue++;
+		status = -EBUSY;
+		goto unlock_ret;
+	}
+	status	= status & (CPDMA_DESC_EOQ | CPDMA_DESC_TD_COMPLETE);
+
+	chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
+	chan_write(chan, cp, desc_dma);
+	chan->count--;
+	chan->stats.good_dequeue++;
+
+	if (status & CPDMA_DESC_EOQ) {
+		chan->stats.requeue++;
+		chan_write(chan, hdp, desc_phys(pool, chan->head));
+	}
+
+	spin_unlock_irqrestore(&chan->lock, flags);
+
+	__cpdma_chan_free(chan, desc, outlen, status);
+	return status;
+
+unlock_ret:
+	spin_unlock_irqrestore(&chan->lock, flags);
+	return status;
+}
+
+int cpdma_chan_process(struct cpdma_chan *chan, int quota)
+{
+	int used = 0, ret = 0;
+
+	if (chan->state != CPDMA_STATE_ACTIVE)
+		return -EINVAL;
+
+	while (used < quota) {
+		ret = __cpdma_chan_process(chan);
+		if (ret < 0)
+			break;
+		used++;
+	}
+	return used;
+}
+
+int cpdma_chan_start(struct cpdma_chan *chan)
+{
+	struct cpdma_ctlr	*ctlr = chan->ctlr;
+	struct cpdma_desc_pool	*pool = ctlr->pool;
+	unsigned long		flags;
+
+	spin_lock_irqsave(&chan->lock, flags);
+	if (chan->state != CPDMA_STATE_IDLE) {
+		spin_unlock_irqrestore(&chan->lock, flags);
+		return -EBUSY;
+	}
+	if (ctlr->state != CPDMA_STATE_ACTIVE) {
+		spin_unlock_irqrestore(&chan->lock, flags);
+		return -EINVAL;
+	}
+	dma_reg_write(ctlr, chan->int_set, chan->mask);
+	chan->state = CPDMA_STATE_ACTIVE;
+	if (chan->head) {
+		chan_write(chan, hdp, desc_phys(pool, chan->head));
+		if (chan->rxfree)
+			chan_write(chan, rxfree, chan->count);
+	}
+
+	spin_unlock_irqrestore(&chan->lock, flags);
+	return 0;
+}
+
+int cpdma_chan_stop(struct cpdma_chan *chan)
+{
+	struct cpdma_ctlr	*ctlr = chan->ctlr;
+	struct cpdma_desc_pool	*pool = ctlr->pool;
+	unsigned long		flags;
+	int			ret;
+	unsigned long		timeout;
+
+	spin_lock_irqsave(&chan->lock, flags);
+	if (chan->state != CPDMA_STATE_ACTIVE) {
+		spin_unlock_irqrestore(&chan->lock, flags);
+		return -EINVAL;
+	}
+
+	chan->state = CPDMA_STATE_TEARDOWN;
+	dma_reg_write(ctlr, chan->int_clear, chan->mask);
+
+	/* trigger teardown */
+	dma_reg_write(ctlr, chan->td, chan->chan_num);
+
+	/* wait for teardown complete */
+	timeout = jiffies + HZ/10;	/* 100 msec */
+	while (time_before(jiffies, timeout)) {
+		u32 cp = chan_read(chan, cp);
+		if ((cp & CPDMA_TEARDOWN_VALUE) == CPDMA_TEARDOWN_VALUE)
+			break;
+		cpu_relax();
+	}
+	WARN_ON(!time_before(jiffies, timeout));
+	chan_write(chan, cp, CPDMA_TEARDOWN_VALUE);
+
+	/* handle completed packets */
+	do {
+		ret = __cpdma_chan_process(chan);
+		if (ret < 0)
+			break;
+	} while ((ret & CPDMA_DESC_TD_COMPLETE) == 0);
+
+	/* remaining packets haven't been tx/rx'ed, clean them up */
+	while (chan->head) {
+		struct cpdma_desc __iomem *desc = chan->head;
+		dma_addr_t next_dma;
+
+		next_dma = desc_read(desc, hw_next);
+		chan->head = desc_from_phys(pool, next_dma);
+		chan->stats.teardown_dequeue++;
+
+		/* issue callback without locks held */
+		spin_unlock_irqrestore(&chan->lock, flags);
+		__cpdma_chan_free(chan, desc, 0, -ENOSYS);
+		spin_lock_irqsave(&chan->lock, flags);
+	}
+
+	chan->state = CPDMA_STATE_IDLE;
+	spin_unlock_irqrestore(&chan->lock, flags);
+	return 0;
+}
+
+int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&chan->lock, flags);
+	if (chan->state != CPDMA_STATE_ACTIVE) {
+		spin_unlock_irqrestore(&chan->lock, flags);
+		return -EINVAL;
+	}
+
+	dma_reg_write(chan->ctlr, enable ? chan->int_set : chan->int_clear,
+		      chan->mask);
+	spin_unlock_irqrestore(&chan->lock, flags);
+
+	return 0;
+}
+
+struct cpdma_control_info {
+	u32		reg;
+	u32		shift, mask;
+	int		access;
+#define ACCESS_RO	BIT(0)
+#define ACCESS_WO	BIT(1)
+#define ACCESS_RW	(ACCESS_RO | ACCESS_WO)
+};
+
+struct cpdma_control_info controls[] = {
+	[CPDMA_CMD_IDLE]	  = {CPDMA_DMACONTROL,	3,  1,      ACCESS_WO},
+	[CPDMA_COPY_ERROR_FRAMES] = {CPDMA_DMACONTROL,	4,  1,      ACCESS_RW},
+	[CPDMA_RX_OFF_LEN_UPDATE] = {CPDMA_DMACONTROL,	2,  1,      ACCESS_RW},
+	[CPDMA_RX_OWNERSHIP_FLIP] = {CPDMA_DMACONTROL,	1,  1,      ACCESS_RW},
+	[CPDMA_TX_PRIO_FIXED]	  = {CPDMA_DMACONTROL,	0,  1,      ACCESS_RW},
+	[CPDMA_STAT_IDLE]	  = {CPDMA_DMASTATUS,	31, 1,      ACCESS_RO},
+	[CPDMA_STAT_TX_ERR_CODE]  = {CPDMA_DMASTATUS,	20, 0xf,    ACCESS_RW},
+	[CPDMA_STAT_TX_ERR_CHAN]  = {CPDMA_DMASTATUS,	16, 0x7,    ACCESS_RW},
+	[CPDMA_STAT_RX_ERR_CODE]  = {CPDMA_DMASTATUS,	12, 0xf,    ACCESS_RW},
+	[CPDMA_STAT_RX_ERR_CHAN]  = {CPDMA_DMASTATUS,	8,  0x7,    ACCESS_RW},
+	[CPDMA_RX_BUFFER_OFFSET]  = {CPDMA_RXBUFFOFS,	0,  0xffff, ACCESS_RW},
+};
+
+int cpdma_control_get(struct cpdma_ctlr *ctlr, int control)
+{
+	unsigned long flags;
+	struct cpdma_control_info *info = &controls[control];
+	int ret;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+
+	ret = -ENOTSUPP;
+	if (!ctlr->params.has_ext_regs)
+		goto unlock_ret;
+
+	ret = -EINVAL;
+	if (ctlr->state != CPDMA_STATE_ACTIVE)
+		goto unlock_ret;
+
+	ret = -ENOENT;
+	if (control < 0 || control >= ARRAY_SIZE(controls))
+		goto unlock_ret;
+
+	ret = -EPERM;
+	if ((info->access & ACCESS_RO) != ACCESS_RO)
+		goto unlock_ret;
+
+	ret = (dma_reg_read(ctlr, info->reg) >> info->shift) & info->mask;
+
+unlock_ret:
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+	return ret;
+}
+
+int cpdma_control_set(struct cpdma_ctlr *ctlr, int control, int value)
+{
+	unsigned long flags;
+	struct cpdma_control_info *info = &controls[control];
+	int ret;
+	u32 val;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+
+	ret = -ENOTSUPP;
+	if (!ctlr->params.has_ext_regs)
+		goto unlock_ret;
+
+	ret = -EINVAL;
+	if (ctlr->state != CPDMA_STATE_ACTIVE)
+		goto unlock_ret;
+
+	ret = -ENOENT;
+	if (control < 0 || control >= ARRAY_SIZE(controls))
+		goto unlock_ret;
+
+	ret = -EPERM;
+	if ((info->access & ACCESS_WO) != ACCESS_WO)
+		goto unlock_ret;
+
+	val  = dma_reg_read(ctlr, info->reg);
+	val &= ~(info->mask << info->shift);
+	val |= (value & info->mask) << info->shift;
+	dma_reg_write(ctlr, info->reg, val);
+	ret = 0;
+
+unlock_ret:
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+	return ret;
+}