Revision de5604231ce4bc8db1bc1dcd27d8540cbedf1518 authored by Nick Piggin on 01 February 2010, 11:24:18 UTC, committed by Linus Torvalds on 02 February 2010, 20:50:47 UTC
RCU list walking of the per-cpu vmap cache was broken.  It did not use
RCU primitives, and also the union of free_list and rcu_head is
obviously wrong (because free_list is indeed the list we are RCU
walking).

While we are there, remove a couple of unused fields from an earlier
iteration.

These APIs aren't actually used anywhere, because of problems with the
XFS conversion.  Christoph has now verified that the problems are solved
with these patches.  Also it is an exported interface, so I think it
will be good to be merged now (and Christoph wants to get the XFS
changes into their local tree).

Cc: stable@kernel.org
Cc: linux-mm@kvack.org
Tested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Nick Piggin <npiggin@suse.de>
--
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 489b24f
Raw File
shdma.c
/*
 * Renesas SuperH DMA Engine support
 *
 * base is drivers/dma/flsdma.c
 *
 * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
 * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
 * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
 *
 * This 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * - DMA of SuperH does not have Hardware DMA chain mode.
 * - MAX DMA size is 16MB.
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/dmaengine.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>
#include <cpu/dma.h>
#include <asm/dma-sh.h>
#include "shdma.h"

/* DMA descriptor control */
enum sh_dmae_desc_status {
	DESC_IDLE,
	DESC_PREPARED,
	DESC_SUBMITTED,
	DESC_COMPLETED,	/* completed, have to call callback */
	DESC_WAITING,	/* callback called, waiting for ack / re-submit */
};

#define NR_DESCS_PER_CHANNEL 32
/*
 * Define the default configuration for dual address memory-memory transfer.
 * The 0x400 value represents auto-request, external->external.
 *
 * And this driver set 4byte burst mode.
 * If you want to change mode, you need to change RS_DEFAULT of value.
 * (ex 1byte burst mode -> (RS_DUAL & ~TS_32)
 */
#define RS_DEFAULT  (RS_DUAL)

static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all);

#define SH_DMAC_CHAN_BASE(id) (dma_base_addr[id])
static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)
{
	ctrl_outl(data, (SH_DMAC_CHAN_BASE(sh_dc->id) + reg));
}

static u32 sh_dmae_readl(struct sh_dmae_chan *sh_dc, u32 reg)
{
	return ctrl_inl((SH_DMAC_CHAN_BASE(sh_dc->id) + reg));
}

static void dmae_init(struct sh_dmae_chan *sh_chan)
{
	u32 chcr = RS_DEFAULT; /* default is DUAL mode */
	sh_dmae_writel(sh_chan, chcr, CHCR);
}

/*
 * Reset DMA controller
 *
 * SH7780 has two DMAOR register
 */
static void sh_dmae_ctl_stop(int id)
{
	unsigned short dmaor = dmaor_read_reg(id);

	dmaor &= ~(DMAOR_NMIF | DMAOR_AE);
	dmaor_write_reg(id, dmaor);
}

static int sh_dmae_rst(int id)
{
	unsigned short dmaor;

	sh_dmae_ctl_stop(id);
	dmaor = dmaor_read_reg(id) | DMAOR_INIT;

	dmaor_write_reg(id, dmaor);
	if (dmaor_read_reg(id) & (DMAOR_AE | DMAOR_NMIF)) {
		pr_warning(KERN_ERR "dma-sh: Can't initialize DMAOR.\n");
		return -EINVAL;
	}
	return 0;
}

static int dmae_is_busy(struct sh_dmae_chan *sh_chan)
{
	u32 chcr = sh_dmae_readl(sh_chan, CHCR);
	if (chcr & CHCR_DE) {
		if (!(chcr & CHCR_TE))
			return -EBUSY; /* working */
	}
	return 0; /* waiting */
}

static inline unsigned int calc_xmit_shift(struct sh_dmae_chan *sh_chan)
{
	u32 chcr = sh_dmae_readl(sh_chan, CHCR);
	return ts_shift[(chcr & CHCR_TS_MASK) >> CHCR_TS_SHIFT];
}

static void dmae_set_reg(struct sh_dmae_chan *sh_chan, struct sh_dmae_regs *hw)
{
	sh_dmae_writel(sh_chan, hw->sar, SAR);
	sh_dmae_writel(sh_chan, hw->dar, DAR);
	sh_dmae_writel(sh_chan, hw->tcr >> calc_xmit_shift(sh_chan), TCR);
}

static void dmae_start(struct sh_dmae_chan *sh_chan)
{
	u32 chcr = sh_dmae_readl(sh_chan, CHCR);

	chcr |= CHCR_DE | CHCR_IE;
	sh_dmae_writel(sh_chan, chcr, CHCR);
}

static void dmae_halt(struct sh_dmae_chan *sh_chan)
{
	u32 chcr = sh_dmae_readl(sh_chan, CHCR);

	chcr &= ~(CHCR_DE | CHCR_TE | CHCR_IE);
	sh_dmae_writel(sh_chan, chcr, CHCR);
}

static int dmae_set_chcr(struct sh_dmae_chan *sh_chan, u32 val)
{
	int ret = dmae_is_busy(sh_chan);
	/* When DMA was working, can not set data to CHCR */
	if (ret)
		return ret;

	sh_dmae_writel(sh_chan, val, CHCR);
	return 0;
}

#define DMARS1_ADDR	0x04
#define DMARS2_ADDR	0x08
#define DMARS_SHIFT 8
#define DMARS_CHAN_MSK 0x01
static int dmae_set_dmars(struct sh_dmae_chan *sh_chan, u16 val)
{
	u32 addr;
	int shift = 0;
	int ret = dmae_is_busy(sh_chan);
	if (ret)
		return ret;

	if (sh_chan->id & DMARS_CHAN_MSK)
		shift = DMARS_SHIFT;

	switch (sh_chan->id) {
	/* DMARS0 */
	case 0:
	case 1:
		addr = SH_DMARS_BASE;
		break;
	/* DMARS1 */
	case 2:
	case 3:
		addr = (SH_DMARS_BASE + DMARS1_ADDR);
		break;
	/* DMARS2 */
	case 4:
	case 5:
		addr = (SH_DMARS_BASE + DMARS2_ADDR);
		break;
	default:
		return -EINVAL;
	}

	ctrl_outw((val << shift) |
		(ctrl_inw(addr) & (shift ? 0xFF00 : 0x00FF)),
		addr);

	return 0;
}

static dma_cookie_t sh_dmae_tx_submit(struct dma_async_tx_descriptor *tx)
{
	struct sh_desc *desc = tx_to_sh_desc(tx), *chunk, *last = desc, *c;
	struct sh_dmae_chan *sh_chan = to_sh_chan(tx->chan);
	dma_async_tx_callback callback = tx->callback;
	dma_cookie_t cookie;

	spin_lock_bh(&sh_chan->desc_lock);

	cookie = sh_chan->common.cookie;
	cookie++;
	if (cookie < 0)
		cookie = 1;

	sh_chan->common.cookie = cookie;
	tx->cookie = cookie;

	/* Mark all chunks of this descriptor as submitted, move to the queue */
	list_for_each_entry_safe(chunk, c, desc->node.prev, node) {
		/*
		 * All chunks are on the global ld_free, so, we have to find
		 * the end of the chain ourselves
		 */
		if (chunk != desc && (chunk->mark == DESC_IDLE ||
				      chunk->async_tx.cookie > 0 ||
				      chunk->async_tx.cookie == -EBUSY ||
				      &chunk->node == &sh_chan->ld_free))
			break;
		chunk->mark = DESC_SUBMITTED;
		/* Callback goes to the last chunk */
		chunk->async_tx.callback = NULL;
		chunk->cookie = cookie;
		list_move_tail(&chunk->node, &sh_chan->ld_queue);
		last = chunk;
	}

	last->async_tx.callback = callback;
	last->async_tx.callback_param = tx->callback_param;

	dev_dbg(sh_chan->dev, "submit #%d@%p on %d: %x[%d] -> %x\n",
		tx->cookie, &last->async_tx, sh_chan->id,
		desc->hw.sar, desc->hw.tcr, desc->hw.dar);

	spin_unlock_bh(&sh_chan->desc_lock);

	return cookie;
}

/* Called with desc_lock held */
static struct sh_desc *sh_dmae_get_desc(struct sh_dmae_chan *sh_chan)
{
	struct sh_desc *desc;

	list_for_each_entry(desc, &sh_chan->ld_free, node)
		if (desc->mark != DESC_PREPARED) {
			BUG_ON(desc->mark != DESC_IDLE);
			list_del(&desc->node);
			return desc;
		}

	return NULL;
}

static int sh_dmae_alloc_chan_resources(struct dma_chan *chan)
{
	struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
	struct sh_desc *desc;

	spin_lock_bh(&sh_chan->desc_lock);
	while (sh_chan->descs_allocated < NR_DESCS_PER_CHANNEL) {
		spin_unlock_bh(&sh_chan->desc_lock);
		desc = kzalloc(sizeof(struct sh_desc), GFP_KERNEL);
		if (!desc) {
			spin_lock_bh(&sh_chan->desc_lock);
			break;
		}
		dma_async_tx_descriptor_init(&desc->async_tx,
					&sh_chan->common);
		desc->async_tx.tx_submit = sh_dmae_tx_submit;
		desc->mark = DESC_IDLE;

		spin_lock_bh(&sh_chan->desc_lock);
		list_add(&desc->node, &sh_chan->ld_free);
		sh_chan->descs_allocated++;
	}
	spin_unlock_bh(&sh_chan->desc_lock);

	return sh_chan->descs_allocated;
}

/*
 * sh_dma_free_chan_resources - Free all resources of the channel.
 */
static void sh_dmae_free_chan_resources(struct dma_chan *chan)
{
	struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
	struct sh_desc *desc, *_desc;
	LIST_HEAD(list);

	/* Prepared and not submitted descriptors can still be on the queue */
	if (!list_empty(&sh_chan->ld_queue))
		sh_dmae_chan_ld_cleanup(sh_chan, true);

	spin_lock_bh(&sh_chan->desc_lock);

	list_splice_init(&sh_chan->ld_free, &list);
	sh_chan->descs_allocated = 0;

	spin_unlock_bh(&sh_chan->desc_lock);

	list_for_each_entry_safe(desc, _desc, &list, node)
		kfree(desc);
}

static struct dma_async_tx_descriptor *sh_dmae_prep_memcpy(
	struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src,
	size_t len, unsigned long flags)
{
	struct sh_dmae_chan *sh_chan;
	struct sh_desc *first = NULL, *prev = NULL, *new;
	size_t copy_size;
	LIST_HEAD(tx_list);
	int chunks = (len + SH_DMA_TCR_MAX) / (SH_DMA_TCR_MAX + 1);

	if (!chan)
		return NULL;

	if (!len)
		return NULL;

	sh_chan = to_sh_chan(chan);

	/* Have to lock the whole loop to protect against concurrent release */
	spin_lock_bh(&sh_chan->desc_lock);

	/*
	 * Chaining:
	 * first descriptor is what user is dealing with in all API calls, its
	 *	cookie is at first set to -EBUSY, at tx-submit to a positive
	 *	number
	 * if more than one chunk is needed further chunks have cookie = -EINVAL
	 * the last chunk, if not equal to the first, has cookie = -ENOSPC
	 * all chunks are linked onto the tx_list head with their .node heads
	 *	only during this function, then they are immediately spliced
	 *	back onto the free list in form of a chain
	 */
	do {
		/* Allocate the link descriptor from the free list */
		new = sh_dmae_get_desc(sh_chan);
		if (!new) {
			dev_err(sh_chan->dev,
				"No free memory for link descriptor\n");
			list_for_each_entry(new, &tx_list, node)
				new->mark = DESC_IDLE;
			list_splice(&tx_list, &sh_chan->ld_free);
			spin_unlock_bh(&sh_chan->desc_lock);
			return NULL;
		}

		copy_size = min(len, (size_t)SH_DMA_TCR_MAX + 1);

		new->hw.sar = dma_src;
		new->hw.dar = dma_dest;
		new->hw.tcr = copy_size;
		if (!first) {
			/* First desc */
			new->async_tx.cookie = -EBUSY;
			first = new;
		} else {
			/* Other desc - invisible to the user */
			new->async_tx.cookie = -EINVAL;
		}

		dev_dbg(sh_chan->dev,
			"chaining %u of %u with %p, dst %x, cookie %d\n",
			copy_size, len, &new->async_tx, dma_dest,
			new->async_tx.cookie);

		new->mark = DESC_PREPARED;
		new->async_tx.flags = flags;
		new->chunks = chunks--;

		prev = new;
		len -= copy_size;
		dma_src += copy_size;
		dma_dest += copy_size;
		/* Insert the link descriptor to the LD ring */
		list_add_tail(&new->node, &tx_list);
	} while (len);

	if (new != first)
		new->async_tx.cookie = -ENOSPC;

	/* Put them back on the free list, so, they don't get lost */
	list_splice_tail(&tx_list, &sh_chan->ld_free);

	spin_unlock_bh(&sh_chan->desc_lock);

	return &first->async_tx;
}

static dma_async_tx_callback __ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
{
	struct sh_desc *desc, *_desc;
	/* Is the "exposed" head of a chain acked? */
	bool head_acked = false;
	dma_cookie_t cookie = 0;
	dma_async_tx_callback callback = NULL;
	void *param = NULL;

	spin_lock_bh(&sh_chan->desc_lock);
	list_for_each_entry_safe(desc, _desc, &sh_chan->ld_queue, node) {
		struct dma_async_tx_descriptor *tx = &desc->async_tx;

		BUG_ON(tx->cookie > 0 && tx->cookie != desc->cookie);
		BUG_ON(desc->mark != DESC_SUBMITTED &&
		       desc->mark != DESC_COMPLETED &&
		       desc->mark != DESC_WAITING);

		/*
		 * queue is ordered, and we use this loop to (1) clean up all
		 * completed descriptors, and to (2) update descriptor flags of
		 * any chunks in a (partially) completed chain
		 */
		if (!all && desc->mark == DESC_SUBMITTED &&
		    desc->cookie != cookie)
			break;

		if (tx->cookie > 0)
			cookie = tx->cookie;

		if (desc->mark == DESC_COMPLETED && desc->chunks == 1) {
			BUG_ON(sh_chan->completed_cookie != desc->cookie - 1);
			sh_chan->completed_cookie = desc->cookie;
		}

		/* Call callback on the last chunk */
		if (desc->mark == DESC_COMPLETED && tx->callback) {
			desc->mark = DESC_WAITING;
			callback = tx->callback;
			param = tx->callback_param;
			dev_dbg(sh_chan->dev, "descriptor #%d@%p on %d callback\n",
				tx->cookie, tx, sh_chan->id);
			BUG_ON(desc->chunks != 1);
			break;
		}

		if (tx->cookie > 0 || tx->cookie == -EBUSY) {
			if (desc->mark == DESC_COMPLETED) {
				BUG_ON(tx->cookie < 0);
				desc->mark = DESC_WAITING;
			}
			head_acked = async_tx_test_ack(tx);
		} else {
			switch (desc->mark) {
			case DESC_COMPLETED:
				desc->mark = DESC_WAITING;
				/* Fall through */
			case DESC_WAITING:
				if (head_acked)
					async_tx_ack(&desc->async_tx);
			}
		}

		dev_dbg(sh_chan->dev, "descriptor %p #%d completed.\n",
			tx, tx->cookie);

		if (((desc->mark == DESC_COMPLETED ||
		      desc->mark == DESC_WAITING) &&
		     async_tx_test_ack(&desc->async_tx)) || all) {
			/* Remove from ld_queue list */
			desc->mark = DESC_IDLE;
			list_move(&desc->node, &sh_chan->ld_free);
		}
	}
	spin_unlock_bh(&sh_chan->desc_lock);

	if (callback)
		callback(param);

	return callback;
}

/*
 * sh_chan_ld_cleanup - Clean up link descriptors
 *
 * This function cleans up the ld_queue of DMA channel.
 */
static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
{
	while (__ld_cleanup(sh_chan, all))
		;
}

static void sh_chan_xfer_ld_queue(struct sh_dmae_chan *sh_chan)
{
	struct sh_desc *sd;

	spin_lock_bh(&sh_chan->desc_lock);
	/* DMA work check */
	if (dmae_is_busy(sh_chan)) {
		spin_unlock_bh(&sh_chan->desc_lock);
		return;
	}

	/* Find the first un-transfer desciptor */
	list_for_each_entry(sd, &sh_chan->ld_queue, node)
		if (sd->mark == DESC_SUBMITTED) {
			/* Get the ld start address from ld_queue */
			dmae_set_reg(sh_chan, &sd->hw);
			dmae_start(sh_chan);
			break;
		}

	spin_unlock_bh(&sh_chan->desc_lock);
}

static void sh_dmae_memcpy_issue_pending(struct dma_chan *chan)
{
	struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
	sh_chan_xfer_ld_queue(sh_chan);
}

static enum dma_status sh_dmae_is_complete(struct dma_chan *chan,
					dma_cookie_t cookie,
					dma_cookie_t *done,
					dma_cookie_t *used)
{
	struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
	dma_cookie_t last_used;
	dma_cookie_t last_complete;

	sh_dmae_chan_ld_cleanup(sh_chan, false);

	last_used = chan->cookie;
	last_complete = sh_chan->completed_cookie;
	BUG_ON(last_complete < 0);

	if (done)
		*done = last_complete;

	if (used)
		*used = last_used;

	return dma_async_is_complete(cookie, last_complete, last_used);
}

static irqreturn_t sh_dmae_interrupt(int irq, void *data)
{
	irqreturn_t ret = IRQ_NONE;
	struct sh_dmae_chan *sh_chan = (struct sh_dmae_chan *)data;
	u32 chcr = sh_dmae_readl(sh_chan, CHCR);

	if (chcr & CHCR_TE) {
		/* DMA stop */
		dmae_halt(sh_chan);

		ret = IRQ_HANDLED;
		tasklet_schedule(&sh_chan->tasklet);
	}

	return ret;
}

#if defined(CONFIG_CPU_SH4)
static irqreturn_t sh_dmae_err(int irq, void *data)
{
	int err = 0;
	struct sh_dmae_device *shdev = (struct sh_dmae_device *)data;

	/* IRQ Multi */
	if (shdev->pdata.mode & SHDMA_MIX_IRQ) {
		int cnt = 0;
		switch (irq) {
#if defined(DMTE6_IRQ) && defined(DMAE1_IRQ)
		case DMTE6_IRQ:
			cnt++;
#endif
		case DMTE0_IRQ:
			if (dmaor_read_reg(cnt) & (DMAOR_NMIF | DMAOR_AE)) {
				disable_irq(irq);
				return IRQ_HANDLED;
			}
		default:
			return IRQ_NONE;
		}
	} else {
		/* reset dma controller */
		err = sh_dmae_rst(0);
		if (err)
			return err;
#ifdef SH_DMAC_BASE1
		if (shdev->pdata.mode & SHDMA_DMAOR1) {
			err = sh_dmae_rst(1);
			if (err)
				return err;
		}
#endif
		disable_irq(irq);
		return IRQ_HANDLED;
	}
}
#endif

static void dmae_do_tasklet(unsigned long data)
{
	struct sh_dmae_chan *sh_chan = (struct sh_dmae_chan *)data;
	struct sh_desc *desc;
	u32 sar_buf = sh_dmae_readl(sh_chan, SAR);

	spin_lock(&sh_chan->desc_lock);
	list_for_each_entry(desc, &sh_chan->ld_queue, node) {
		if ((desc->hw.sar + desc->hw.tcr) == sar_buf &&
		    desc->mark == DESC_SUBMITTED) {
			dev_dbg(sh_chan->dev, "done #%d@%p dst %u\n",
				desc->async_tx.cookie, &desc->async_tx,
				desc->hw.dar);
			desc->mark = DESC_COMPLETED;
			break;
		}
	}
	spin_unlock(&sh_chan->desc_lock);

	/* Next desc */
	sh_chan_xfer_ld_queue(sh_chan);
	sh_dmae_chan_ld_cleanup(sh_chan, false);
}

static unsigned int get_dmae_irq(unsigned int id)
{
	unsigned int irq = 0;
	if (id < ARRAY_SIZE(dmte_irq_map))
		irq = dmte_irq_map[id];
	return irq;
}

static int __devinit sh_dmae_chan_probe(struct sh_dmae_device *shdev, int id)
{
	int err;
	unsigned int irq = get_dmae_irq(id);
	unsigned long irqflags = IRQF_DISABLED;
	struct sh_dmae_chan *new_sh_chan;

	/* alloc channel */
	new_sh_chan = kzalloc(sizeof(struct sh_dmae_chan), GFP_KERNEL);
	if (!new_sh_chan) {
		dev_err(shdev->common.dev,
			"No free memory for allocating dma channels!\n");
		return -ENOMEM;
	}

	new_sh_chan->dev = shdev->common.dev;
	new_sh_chan->id = id;

	/* Init DMA tasklet */
	tasklet_init(&new_sh_chan->tasklet, dmae_do_tasklet,
			(unsigned long)new_sh_chan);

	/* Init the channel */
	dmae_init(new_sh_chan);

	spin_lock_init(&new_sh_chan->desc_lock);

	/* Init descripter manage list */
	INIT_LIST_HEAD(&new_sh_chan->ld_queue);
	INIT_LIST_HEAD(&new_sh_chan->ld_free);

	/* copy struct dma_device */
	new_sh_chan->common.device = &shdev->common;

	/* Add the channel to DMA device channel list */
	list_add_tail(&new_sh_chan->common.device_node,
			&shdev->common.channels);
	shdev->common.chancnt++;

	if (shdev->pdata.mode & SHDMA_MIX_IRQ) {
		irqflags = IRQF_SHARED;
#if defined(DMTE6_IRQ)
		if (irq >= DMTE6_IRQ)
			irq = DMTE6_IRQ;
		else
#endif
			irq = DMTE0_IRQ;
	}

	snprintf(new_sh_chan->dev_id, sizeof(new_sh_chan->dev_id),
			"sh-dmae%d", new_sh_chan->id);

	/* set up channel irq */
	err = request_irq(irq, &sh_dmae_interrupt, irqflags,
			  new_sh_chan->dev_id, new_sh_chan);
	if (err) {
		dev_err(shdev->common.dev, "DMA channel %d request_irq error "
			"with return %d\n", id, err);
		goto err_no_irq;
	}

	/* CHCR register control function */
	new_sh_chan->set_chcr = dmae_set_chcr;
	/* DMARS register control function */
	new_sh_chan->set_dmars = dmae_set_dmars;

	shdev->chan[id] = new_sh_chan;
	return 0;

err_no_irq:
	/* remove from dmaengine device node */
	list_del(&new_sh_chan->common.device_node);
	kfree(new_sh_chan);
	return err;
}

static void sh_dmae_chan_remove(struct sh_dmae_device *shdev)
{
	int i;

	for (i = shdev->common.chancnt - 1 ; i >= 0 ; i--) {
		if (shdev->chan[i]) {
			struct sh_dmae_chan *shchan = shdev->chan[i];
			if (!(shdev->pdata.mode & SHDMA_MIX_IRQ))
				free_irq(dmte_irq_map[i], shchan);

			list_del(&shchan->common.device_node);
			kfree(shchan);
			shdev->chan[i] = NULL;
		}
	}
	shdev->common.chancnt = 0;
}

static int __init sh_dmae_probe(struct platform_device *pdev)
{
	int err = 0, cnt, ecnt;
	unsigned long irqflags = IRQF_DISABLED;
#if defined(CONFIG_CPU_SH4)
	int eirq[] = { DMAE0_IRQ,
#if defined(DMAE1_IRQ)
			DMAE1_IRQ
#endif
		};
#endif
	struct sh_dmae_device *shdev;

	/* get platform data */
	if (!pdev->dev.platform_data)
		return -ENODEV;

	shdev = kzalloc(sizeof(struct sh_dmae_device), GFP_KERNEL);
	if (!shdev) {
		dev_err(&pdev->dev, "No enough memory\n");
		return -ENOMEM;
	}

	/* platform data */
	memcpy(&shdev->pdata, pdev->dev.platform_data,
			sizeof(struct sh_dmae_pdata));

	/* reset dma controller */
	err = sh_dmae_rst(0);
	if (err)
		goto rst_err;

	/* SH7780/85/23 has DMAOR1 */
	if (shdev->pdata.mode & SHDMA_DMAOR1) {
		err = sh_dmae_rst(1);
		if (err)
			goto rst_err;
	}

	INIT_LIST_HEAD(&shdev->common.channels);

	dma_cap_set(DMA_MEMCPY, shdev->common.cap_mask);
	shdev->common.device_alloc_chan_resources
		= sh_dmae_alloc_chan_resources;
	shdev->common.device_free_chan_resources = sh_dmae_free_chan_resources;
	shdev->common.device_prep_dma_memcpy = sh_dmae_prep_memcpy;
	shdev->common.device_is_tx_complete = sh_dmae_is_complete;
	shdev->common.device_issue_pending = sh_dmae_memcpy_issue_pending;
	shdev->common.dev = &pdev->dev;
	/* Default transfer size of 32 bytes requires 32-byte alignment */
	shdev->common.copy_align = 5;

#if defined(CONFIG_CPU_SH4)
	/* Non Mix IRQ mode SH7722/SH7730 etc... */
	if (shdev->pdata.mode & SHDMA_MIX_IRQ) {
		irqflags = IRQF_SHARED;
		eirq[0] = DMTE0_IRQ;
#if defined(DMTE6_IRQ) && defined(DMAE1_IRQ)
		eirq[1] = DMTE6_IRQ;
#endif
	}

	for (ecnt = 0 ; ecnt < ARRAY_SIZE(eirq); ecnt++) {
		err = request_irq(eirq[ecnt], sh_dmae_err, irqflags,
				  "DMAC Address Error", shdev);
		if (err) {
			dev_err(&pdev->dev, "DMA device request_irq"
				"error (irq %d) with return %d\n",
				eirq[ecnt], err);
			goto eirq_err;
		}
	}
#endif /* CONFIG_CPU_SH4 */

	/* Create DMA Channel */
	for (cnt = 0 ; cnt < MAX_DMA_CHANNELS ; cnt++) {
		err = sh_dmae_chan_probe(shdev, cnt);
		if (err)
			goto chan_probe_err;
	}

	platform_set_drvdata(pdev, shdev);
	dma_async_device_register(&shdev->common);

	return err;

chan_probe_err:
	sh_dmae_chan_remove(shdev);

eirq_err:
	for (ecnt-- ; ecnt >= 0; ecnt--)
		free_irq(eirq[ecnt], shdev);

rst_err:
	kfree(shdev);

	return err;
}

static int __exit sh_dmae_remove(struct platform_device *pdev)
{
	struct sh_dmae_device *shdev = platform_get_drvdata(pdev);

	dma_async_device_unregister(&shdev->common);

	if (shdev->pdata.mode & SHDMA_MIX_IRQ) {
		free_irq(DMTE0_IRQ, shdev);
#if defined(DMTE6_IRQ)
		free_irq(DMTE6_IRQ, shdev);
#endif
	}

	/* channel data remove */
	sh_dmae_chan_remove(shdev);

	if (!(shdev->pdata.mode & SHDMA_MIX_IRQ)) {
		free_irq(DMAE0_IRQ, shdev);
#if defined(DMAE1_IRQ)
		free_irq(DMAE1_IRQ, shdev);
#endif
	}
	kfree(shdev);

	return 0;
}

static void sh_dmae_shutdown(struct platform_device *pdev)
{
	struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
	sh_dmae_ctl_stop(0);
	if (shdev->pdata.mode & SHDMA_DMAOR1)
		sh_dmae_ctl_stop(1);
}

static struct platform_driver sh_dmae_driver = {
	.remove		= __exit_p(sh_dmae_remove),
	.shutdown	= sh_dmae_shutdown,
	.driver = {
		.name	= "sh-dma-engine",
	},
};

static int __init sh_dmae_init(void)
{
	return platform_driver_probe(&sh_dmae_driver, sh_dmae_probe);
}
module_init(sh_dmae_init);

static void __exit sh_dmae_exit(void)
{
	platform_driver_unregister(&sh_dmae_driver);
}
module_exit(sh_dmae_exit);

MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>");
MODULE_DESCRIPTION("Renesas SH DMA Engine driver");
MODULE_LICENSE("GPL");
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