[mirror_ubuntu-zesty-kernel.git] / drivers / mmc / host / tmio_mmc_dma.c

/*
 * linux/drivers/mmc/tmio_mmc_dma.c
 *
 * Copyright (C) 2010-2011 Guennadi Liakhovetski
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * DMA function for TMIO MMC implementations
 */

#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/mfd/tmio.h>
#include <linux/mmc/host.h>
#include <linux/mmc/tmio.h>
#include <linux/pagemap.h>
#include <linux/scatterlist.h>

#include "tmio_mmc.h"

#define TMIO_MMC_MIN_DMA_LEN 8

void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
{
	if (!host->chan_tx || !host->chan_rx)
		return;

#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE)
	/* Switch DMA mode on or off - SuperH specific? */
	sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? 2 : 0);
#endif
}

static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
{
	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
	struct dma_async_tx_descriptor *desc = NULL;
	struct dma_chan *chan = host->chan_rx;
	struct tmio_mmc_data *pdata = host->pdata;
	dma_cookie_t cookie;
	int ret, i;
	bool aligned = true, multiple = true;
	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;

	for_each_sg(sg, sg_tmp, host->sg_len, i) {
		if (sg_tmp->offset & align)
			aligned = false;
		if (sg_tmp->length & align) {
			multiple = false;
			break;
		}
	}

	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_CACHE_SIZE ||
			  (align & PAGE_MASK))) || !multiple) {
		ret = -EINVAL;
		goto pio;
	}

	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
		host->force_pio = true;
		return;
	}

	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);

	/* The only sg element can be unaligned, use our bounce buffer then */
	if (!aligned) {
		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
		host->sg_ptr = &host->bounce_sg;
		sg = host->sg_ptr;
	}

	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
	if (ret > 0)
		desc = chan->device->device_prep_slave_sg(chan, sg, ret,
			DMA_DEV_TO_MEM, DMA_CTRL_ACK);

	if (desc) {
		cookie = dmaengine_submit(desc);
		if (cookie < 0) {
			desc = NULL;
			ret = cookie;
		}
	}
	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
		__func__, host->sg_len, ret, cookie, host->mrq);

pio:
	if (!desc) {
		/* DMA failed, fall back to PIO */
		if (ret >= 0)
			ret = -EIO;
		host->chan_rx = NULL;
		dma_release_channel(chan);
		/* Free the Tx channel too */
		chan = host->chan_tx;
		if (chan) {
			host->chan_tx = NULL;
			dma_release_channel(chan);
		}
		dev_warn(&host->pdev->dev,
			 "DMA failed: %d, falling back to PIO\n", ret);
		tmio_mmc_enable_dma(host, false);
	}

	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__,
		desc, cookie, host->sg_len);
}

static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
{
	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
	struct dma_async_tx_descriptor *desc = NULL;
	struct dma_chan *chan = host->chan_tx;
	struct tmio_mmc_data *pdata = host->pdata;
	dma_cookie_t cookie;
	int ret, i;
	bool aligned = true, multiple = true;
	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;

	for_each_sg(sg, sg_tmp, host->sg_len, i) {
		if (sg_tmp->offset & align)
			aligned = false;
		if (sg_tmp->length & align) {
			multiple = false;
			break;
		}
	}

	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_CACHE_SIZE ||
			  (align & PAGE_MASK))) || !multiple) {
		ret = -EINVAL;
		goto pio;
	}

	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
		host->force_pio = true;
		return;
	}

	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);

	/* The only sg element can be unaligned, use our bounce buffer then */
	if (!aligned) {
		unsigned long flags;
		void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
		memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
		tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
		host->sg_ptr = &host->bounce_sg;
		sg = host->sg_ptr;
	}

	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
	if (ret > 0)
		desc = chan->device->device_prep_slave_sg(chan, sg, ret,
			DMA_MEM_TO_DEV, DMA_CTRL_ACK);

	if (desc) {
		cookie = dmaengine_submit(desc);
		if (cookie < 0) {
			desc = NULL;
			ret = cookie;
		}
	}
	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
		__func__, host->sg_len, ret, cookie, host->mrq);

pio:
	if (!desc) {
		/* DMA failed, fall back to PIO */
		if (ret >= 0)
			ret = -EIO;
		host->chan_tx = NULL;
		dma_release_channel(chan);
		/* Free the Rx channel too */
		chan = host->chan_rx;
		if (chan) {
			host->chan_rx = NULL;
			dma_release_channel(chan);
		}
		dev_warn(&host->pdev->dev,
			 "DMA failed: %d, falling back to PIO\n", ret);
		tmio_mmc_enable_dma(host, false);
	}

	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__,
		desc, cookie);
}

void tmio_mmc_start_dma(struct tmio_mmc_host *host,
			       struct mmc_data *data)
{
	if (data->flags & MMC_DATA_READ) {
		if (host->chan_rx)
			tmio_mmc_start_dma_rx(host);
	} else {
		if (host->chan_tx)
			tmio_mmc_start_dma_tx(host);
	}
}

static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
{
	struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
	struct dma_chan *chan = NULL;

	spin_lock_irq(&host->lock);

	if (host && host->data) {
		if (host->data->flags & MMC_DATA_READ)
			chan = host->chan_rx;
		else
			chan = host->chan_tx;
	}

	spin_unlock_irq(&host->lock);

	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);

	if (chan)
		dma_async_issue_pending(chan);
}

static void tmio_mmc_tasklet_fn(unsigned long arg)
{
	struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;

	spin_lock_irq(&host->lock);

	if (!host->data)
		goto out;

	if (host->data->flags & MMC_DATA_READ)
		dma_unmap_sg(host->chan_rx->device->dev,
			     host->sg_ptr, host->sg_len,
			     DMA_FROM_DEVICE);
	else
		dma_unmap_sg(host->chan_tx->device->dev,
			     host->sg_ptr, host->sg_len,
			     DMA_TO_DEVICE);

	tmio_mmc_do_data_irq(host);
out:
	spin_unlock_irq(&host->lock);
}

/* It might be necessary to make filter MFD specific */
static bool tmio_mmc_filter(struct dma_chan *chan, void *arg)
{
	dev_dbg(chan->device->dev, "%s: slave data %p\n", __func__, arg);
	chan->private = arg;
	return true;
}

void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata)
{
	/* We can only either use DMA for both Tx and Rx or not use it at all */
	if (!pdata->dma)
		return;

	if (!host->chan_tx && !host->chan_rx) {
		dma_cap_mask_t mask;

		dma_cap_zero(mask);
		dma_cap_set(DMA_SLAVE, mask);

		host->chan_tx = dma_request_channel(mask, tmio_mmc_filter,
						    pdata->dma->chan_priv_tx);
		dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
			host->chan_tx);

		if (!host->chan_tx)
			return;

		host->chan_rx = dma_request_channel(mask, tmio_mmc_filter,
						    pdata->dma->chan_priv_rx);
		dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
			host->chan_rx);

		if (!host->chan_rx)
			goto ereqrx;

		host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
		if (!host->bounce_buf)
			goto ebouncebuf;

		tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
		tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
	}

	tmio_mmc_enable_dma(host, true);

	return;

ebouncebuf:
	dma_release_channel(host->chan_rx);
	host->chan_rx = NULL;
ereqrx:
	dma_release_channel(host->chan_tx);
	host->chan_tx = NULL;
}

void tmio_mmc_release_dma(struct tmio_mmc_host *host)
{
	if (host->chan_tx) {
		struct dma_chan *chan = host->chan_tx;
		host->chan_tx = NULL;
		dma_release_channel(chan);
	}
	if (host->chan_rx) {
		struct dma_chan *chan = host->chan_rx;
		host->chan_rx = NULL;
		dma_release_channel(chan);
	}
	if (host->bounce_buf) {
		free_pages((unsigned long)host->bounce_buf, 0);
		host->bounce_buf = NULL;
	}
}
Commit	Line	Data
b6147490 GL	1	/*
	2	* linux/drivers/mmc/tmio_mmc_dma.c
	3	*
	4	* Copyright (C) 2010-2011 Guennadi Liakhovetski
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* DMA function for TMIO MMC implementations
	11	*/
	12
	13	#include <linux/device.h>
b7f080cf	14	#include <linux/dma-mapping.h>
b6147490 GL	15	#include <linux/dmaengine.h>
	16	#include <linux/mfd/tmio.h>
	17	#include <linux/mmc/host.h>
cba179ae	18	#include <linux/mmc/tmio.h>
b6147490 GL	19	#include <linux/pagemap.h>
	20	#include <linux/scatterlist.h>
	21
	22	#include "tmio_mmc.h"
	23
	24	#define TMIO_MMC_MIN_DMA_LEN 8
	25
162f43e3	26	void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
b6147490	27	{
162f43e3 GL	28	if (!host->chan_tx \|\| !host->chan_rx)
	29	return;
	30
b6147490 GL	31	#if defined(CONFIG_SUPERH) \|\| defined(CONFIG_ARCH_SHMOBILE)
b6147490 GL	32	/* Switch DMA mode on or off - SuperH specific? */
332bdb50	33	sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? 2 : 0);
b6147490 GL	34	#endif
	35	}
	36
	37	static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
	38	{
	39	struct scatterlist sg = host->sg_ptr, sg_tmp;
	40	struct dma_async_tx_descriptor *desc = NULL;
	41	struct dma_chan *chan = host->chan_rx;
	42	struct tmio_mmc_data *pdata = host->pdata;
	43	dma_cookie_t cookie;
	44	int ret, i;
	45	bool aligned = true, multiple = true;
	46	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;
	47
	48	for_each_sg(sg, sg_tmp, host->sg_len, i) {
	49	if (sg_tmp->offset & align)
	50	aligned = false;
	51	if (sg_tmp->length & align) {
	52	multiple = false;
	53	break;
	54	}
	55	}
	56
	57	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_CACHE_SIZE \|\|
	58	(align & PAGE_MASK))) \|\| !multiple) {
	59	ret = -EINVAL;
	60	goto pio;
	61	}
	62
	63	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
	64	host->force_pio = true;
	65	return;
	66	}
	67
	68	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_RXRDY);
	69
	70	/* The only sg element can be unaligned, use our bounce buffer then */
	71	if (!aligned) {
	72	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
	73	host->sg_ptr = &host->bounce_sg;
	74	sg = host->sg_ptr;
	75	}
	76
	77	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
	78	if (ret > 0)
	79	desc = chan->device->device_prep_slave_sg(chan, sg, ret,
05f5799c	80	DMA_DEV_TO_MEM, DMA_CTRL_ACK);
b6147490 GL	81
	82	if (desc) {
	83	cookie = dmaengine_submit(desc);
	84	if (cookie < 0) {
	85	desc = NULL;
	86	ret = cookie;
	87	}
	88	}
	89	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
	90	__func__, host->sg_len, ret, cookie, host->mrq);
	91
	92	pio:
	93	if (!desc) {
	94	/* DMA failed, fall back to PIO */
	95	if (ret >= 0)
	96	ret = -EIO;
	97	host->chan_rx = NULL;
	98	dma_release_channel(chan);
	99	/* Free the Tx channel too */
	100	chan = host->chan_tx;
	101	if (chan) {
	102	host->chan_tx = NULL;
	103	dma_release_channel(chan);
	104	}
	105	dev_warn(&host->pdev->dev,
	106	"DMA failed: %d, falling back to PIO\n", ret);
	107	tmio_mmc_enable_dma(host, false);
	108	}
	109
	110	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__,
	111	desc, cookie, host->sg_len);
	112	}
	113
	114	static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
	115	{
	116	struct scatterlist sg = host->sg_ptr, sg_tmp;
	117	struct dma_async_tx_descriptor *desc = NULL;
	118	struct dma_chan *chan = host->chan_tx;
	119	struct tmio_mmc_data *pdata = host->pdata;
	120	dma_cookie_t cookie;
	121	int ret, i;
	122	bool aligned = true, multiple = true;
	123	unsigned int align = (1 << pdata->dma->alignment_shift) - 1;
	124
	125	for_each_sg(sg, sg_tmp, host->sg_len, i) {
	126	if (sg_tmp->offset & align)
	127	aligned = false;
	128	if (sg_tmp->length & align) {
	129	multiple = false;
	130	break;
	131	}
	132	}
	133
	134	if ((!aligned && (host->sg_len > 1 \|\| sg->length > PAGE_CACHE_SIZE \|\|
	135	(align & PAGE_MASK))) \|\| !multiple) {
	136	ret = -EINVAL;
	137	goto pio;
	138	}
	139
	140	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
	141	host->force_pio = true;
	142	return;
	143	}
	144
145	tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_TXRQ);
146
147	/* The only sg element can be unaligned, use our bounce buffer then */
148	if (!aligned) {
149	unsigned long flags;
150	void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
151	sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
152	memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
153	tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
154	host->sg_ptr = &host->bounce_sg;
155	sg = host->sg_ptr;
156	}
157
158	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
159	if (ret > 0)
160	desc = chan->device->device_prep_slave_sg(chan, sg, ret,
05f5799c	161	DMA_MEM_TO_DEV, DMA_CTRL_ACK);
b6147490 GL	162
	163	if (desc) {
	164	cookie = dmaengine_submit(desc);
	165	if (cookie < 0) {
	166	desc = NULL;
	167	ret = cookie;
	168	}
	169	}
	170	dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n",
	171	__func__, host->sg_len, ret, cookie, host->mrq);
	172
	173	pio:
	174	if (!desc) {
	175	/* DMA failed, fall back to PIO */
	176	if (ret >= 0)
	177	ret = -EIO;
	178	host->chan_tx = NULL;
	179	dma_release_channel(chan);
	180	/* Free the Rx channel too */
	181	chan = host->chan_rx;
	182	if (chan) {
	183	host->chan_rx = NULL;
	184	dma_release_channel(chan);
	185	}
	186	dev_warn(&host->pdev->dev,
	187	"DMA failed: %d, falling back to PIO\n", ret);
	188	tmio_mmc_enable_dma(host, false);
	189	}
	190
	191	dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__,
	192	desc, cookie);
	193	}
	194
	195	void tmio_mmc_start_dma(struct tmio_mmc_host *host,
	196	struct mmc_data *data)
	197	{
	198	if (data->flags & MMC_DATA_READ) {
	199	if (host->chan_rx)
	200	tmio_mmc_start_dma_rx(host);
	201	} else {
	202	if (host->chan_tx)
	203	tmio_mmc_start_dma_tx(host);
	204	}
	205	}
	206
	207	static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
	208	{
	209	struct tmio_mmc_host host = (struct tmio_mmc_host )priv;
	210	struct dma_chan *chan = NULL;
	211
	212	spin_lock_irq(&host->lock);
	213
	214	if (host && host->data) {
	215	if (host->data->flags & MMC_DATA_READ)
	216	chan = host->chan_rx;
	217	else
	218	chan = host->chan_tx;
	219	}
	220
	221	spin_unlock_irq(&host->lock);
	222
	223	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
	224
	225	if (chan)
226	dma_async_issue_pending(chan);
227	}
228
229	static void tmio_mmc_tasklet_fn(unsigned long arg)
230	{
231	struct tmio_mmc_host host = (struct tmio_mmc_host )arg;
232
233	spin_lock_irq(&host->lock);
234
235	if (!host->data)
236	goto out;
237
238	if (host->data->flags & MMC_DATA_READ)
239	dma_unmap_sg(host->chan_rx->device->dev,
240	host->sg_ptr, host->sg_len,
241	DMA_FROM_DEVICE);
242	else
243	dma_unmap_sg(host->chan_tx->device->dev,
244	host->sg_ptr, host->sg_len,
245	DMA_TO_DEVICE);
246
247	tmio_mmc_do_data_irq(host);
248	out:
249	spin_unlock_irq(&host->lock);
250	}
251
252	/* It might be necessary to make filter MFD specific */
253	static bool tmio_mmc_filter(struct dma_chan chan, void arg)
254	{
255	dev_dbg(chan->device->dev, "%s: slave data %p\n", __func__, arg);
256	chan->private = arg;
257	return true;
258	}
259
260	void tmio_mmc_request_dma(struct tmio_mmc_host host, struct tmio_mmc_data pdata)
261	{
262	/* We can only either use DMA for both Tx and Rx or not use it at all */
e6ee7182 GL	263	if (!pdata->dma)
	264	return;
	265
	266	if (!host->chan_tx && !host->chan_rx) {
b6147490 GL	267	dma_cap_mask_t mask;
	268
	269	dma_cap_zero(mask);
	270	dma_cap_set(DMA_SLAVE, mask);
	271
	272	host->chan_tx = dma_request_channel(mask, tmio_mmc_filter,
	273	pdata->dma->chan_priv_tx);
	274	dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
	275	host->chan_tx);
	276
	277	if (!host->chan_tx)
	278	return;
	279
	280	host->chan_rx = dma_request_channel(mask, tmio_mmc_filter,
	281	pdata->dma->chan_priv_rx);
	282	dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
	283	host->chan_rx);
	284
	285	if (!host->chan_rx)
	286	goto ereqrx;
	287
	288	host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL \| GFP_DMA);
	289	if (!host->bounce_buf)
	290	goto ebouncebuf;
	291
	292	tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
	293	tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
e6ee7182	294	}
b6147490	295
e6ee7182 GL	296	tmio_mmc_enable_dma(host, true);
	297
	298	return;
b6147490	299
b6147490	300	ebouncebuf:
e6ee7182 GL	301	dma_release_channel(host->chan_rx);
e6ee7182 GL	302	host->chan_rx = NULL;
b6147490	303	ereqrx:
e6ee7182 GL	304	dma_release_channel(host->chan_tx);
e6ee7182 GL	305	host->chan_tx = NULL;
b6147490 GL	306	}
	307
	308	void tmio_mmc_release_dma(struct tmio_mmc_host *host)
	309	{
	310	if (host->chan_tx) {
	311	struct dma_chan *chan = host->chan_tx;
	312	host->chan_tx = NULL;
	313	dma_release_channel(chan);
	314	}
	315	if (host->chan_rx) {
	316	struct dma_chan *chan = host->chan_rx;
	317	host->chan_rx = NULL;
	318	dma_release_channel(chan);
	319	}
	320	if (host->bounce_buf) {
	321	free_pages((unsigned long)host->bounce_buf, 0);
	322	host->bounce_buf = NULL;
	323	}
	324	}