Commit 4d112426 authored by Maxime Ripard's avatar Maxime Ripard Committed by Vinod Koul
Browse files

dmaengine: hdmac: Add memset capabilities 



Just like for the XDMAC, the SoCs that embed the HDMAC don't have any kind
of GPU, and need to accelerate a few framebuffer-related operations through
their DMA controller.

However, unlike the XDMAC, the HDMAC doesn't have the memset capability
built-in. That can be easily emulated though, by doing a transfer with a
fixed address on the variable that holds the value we want to set.

Signed-off-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 8a4ce226

drivers/dma/at_hdmac.c

+118 −3
Original line number Diff line number Diff line
@@ -390,6 +390,7 @@ static void 
atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)

{

	struct dma_async_tx_descriptor	*txd = &desc->txd;

	struct at_dma			*atdma = to_at_dma(atchan->chan_common.device);



	dev_vdbg(chan2dev(&atchan->chan_common),

		"descriptor %u complete\n", txd->cookie);
@@ -398,6 +399,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc) 
	if (!atc_chan_is_cyclic(atchan))

		dma_cookie_complete(txd);



	/* If the transfer was a memset, free our temporary buffer */

	if (desc->memset) {

		dma_pool_free(atdma->memset_pool, desc->memset_vaddr,

			      desc->memset_paddr);

		desc->memset = false;

	}



	/* move children to free_list */

	list_splice_init(&desc->tx_list, &atchan->free_list);

	/* move myself to free_list */
@@ -820,6 +828,93 @@ err_desc_get: 
	return NULL;

}



/**

 * atc_prep_dma_memset - prepare a memcpy operation

 * @chan: the channel to prepare operation on

 * @dest: operation virtual destination address

 * @value: value to set memory buffer to

 * @len: operation length

 * @flags: tx descriptor status flags

 */

static struct dma_async_tx_descriptor *

atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,

		    size_t len, unsigned long flags)

{

	struct at_dma_chan	*atchan = to_at_dma_chan(chan);

	struct at_dma		*atdma = to_at_dma(chan->device);

	struct at_desc		*desc = NULL;

	size_t			xfer_count;

	u32			ctrla;

	u32			ctrlb;



	dev_vdbg(chan2dev(chan), "%s: d0x%x v0x%x l0x%zx f0x%lx\n", __func__,

		dest, value, len, flags);



	if (unlikely(!len)) {

		dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__);

		return NULL;

	}



	if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {

		dev_dbg(chan2dev(chan), "%s: buffer is not aligned\n",

			__func__);

		return NULL;

	}



	xfer_count = len >> 2;

	if (xfer_count > ATC_BTSIZE_MAX) {

		dev_err(chan2dev(chan), "%s: buffer is too big\n",

			__func__);

		return NULL;

	}



	ctrlb =   ATC_DEFAULT_CTRLB | ATC_IEN

		| ATC_SRC_ADDR_MODE_FIXED

		| ATC_DST_ADDR_MODE_INCR

		| ATC_FC_MEM2MEM;



	ctrla = ATC_SRC_WIDTH(2) |

		ATC_DST_WIDTH(2);



	desc = atc_desc_get(atchan);

	if (!desc) {

		dev_err(chan2dev(chan), "%s: can't get a descriptor\n",

			__func__);

		return NULL;

	}



	desc->memset_vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC,

					    &desc->memset_paddr);

	if (!desc->memset_vaddr) {

		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",

			__func__);

		goto err_put_desc;

	}



	*desc->memset_vaddr = value;

	desc->memset = true;



	desc->lli.saddr = desc->memset_paddr;

	desc->lli.daddr = dest;

	desc->lli.ctrla = ctrla | xfer_count;

	desc->lli.ctrlb = ctrlb;



	desc->txd.cookie = -EBUSY;

	desc->len = len;

	desc->total_len = len;



	/* set end-of-link on the descriptor */

	set_desc_eol(desc);



	desc->txd.flags = flags;



	return &desc->txd;



err_put_desc:

	atc_desc_put(atchan, desc);

	return NULL;

}





/**

 * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
@@ -1713,6 +1808,8 @@ static int __init at_dma_probe(struct platform_device *pdev) 
	dma_cap_set(DMA_SG, at91sam9rl_config.cap_mask);

	dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask);

	dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask);

	dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask);

	dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask);

	dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask);

	dma_cap_set(DMA_SG, at91sam9g45_config.cap_mask);
@@ -1776,7 +1873,16 @@ static int __init at_dma_probe(struct platform_device *pdev) 
	if (!atdma->dma_desc_pool) {

		dev_err(&pdev->dev, "No memory for descriptors dma pool\n");

		err = -ENOMEM;

		goto err_pool_create;

		goto err_desc_pool_create;

	}



	/* create a pool of consistent memory blocks for memset blocks */

	atdma->memset_pool = dma_pool_create("at_hdmac_memset_pool",

					     &pdev->dev, sizeof(int), 4, 0);

	if (!atdma->memset_pool) {

		dev_err(&pdev->dev, "No memory for memset dma pool\n");

		err = -ENOMEM;

		goto err_memset_pool_create;

	}



	/* clear any pending interrupt */
@@ -1822,6 +1928,11 @@ static int __init at_dma_probe(struct platform_device *pdev) 
	if (dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask))

		atdma->dma_common.device_prep_dma_memcpy = atc_prep_dma_memcpy;



	if (dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask)) {

		atdma->dma_common.device_prep_dma_memset = atc_prep_dma_memset;

		atdma->dma_common.fill_align = DMAENGINE_ALIGN_4_BYTES;

	}



	if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)) {

		atdma->dma_common.device_prep_slave_sg = atc_prep_slave_sg;

		/* controller can do slave DMA: can trigger cyclic transfers */
@@ -1842,8 +1953,9 @@ static int __init at_dma_probe(struct platform_device *pdev) 


	dma_writel(atdma, EN, AT_DMA_ENABLE);



	dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s), %d channels\n",

	dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s%s), %d channels\n",

	  dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "",

	  dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask) ? "set " : "",

	  dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)  ? "slave " : "",

	  dma_has_cap(DMA_SG, atdma->dma_common.cap_mask)  ? "sg-cpy " : "",

	  plat_dat->nr_channels);
@@ -1868,8 +1980,10 @@ static int __init at_dma_probe(struct platform_device *pdev) 


err_of_dma_controller_register:

	dma_async_device_unregister(&atdma->dma_common);

	dma_pool_destroy(atdma->memset_pool);

err_memset_pool_create:

	dma_pool_destroy(atdma->dma_desc_pool);

err_pool_create:

err_desc_pool_create:

	free_irq(platform_get_irq(pdev, 0), atdma);

err_irq:

	clk_disable_unprepare(atdma->clk);
@@ -1894,6 +2008,7 @@ static int at_dma_remove(struct platform_device *pdev) 
	at_dma_off(atdma);

	dma_async_device_unregister(&atdma->dma_common);



	dma_pool_destroy(atdma->memset_pool);

	dma_pool_destroy(atdma->dma_desc_pool);

	free_irq(platform_get_irq(pdev, 0), atdma);

drivers/dma/at_hdmac_regs.h

+6 −0
Original line number Diff line number Diff line
@@ -201,6 +201,11 @@ struct at_desc { 
	size_t				boundary;

	size_t				dst_hole;

	size_t				src_hole;



	/* Memset temporary buffer */

	bool				memset;

	dma_addr_t			memset_paddr;

	int				*memset_vaddr;

};



static inline struct at_desc *
@@ -331,6 +336,7 @@ struct at_dma { 
	u8			all_chan_mask;



	struct dma_pool		*dma_desc_pool;

	struct dma_pool		*memset_pool;

	/* AT THE END channels table */

	struct at_dma_chan	chan[0];

};

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