Commit e8e3b771 authored by Suzuki K Poulose's avatar Suzuki K Poulose Committed by Greg Kroah-Hartman
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coresight: tmc-etr buf: Add TMC scatter gather mode backend 



Add the support for Scatter-Gather mode to the etr-buf layer.
Since we now have two different modes, we choose the backend
based on a set of conditions, documented in the code.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 75f4e361

drivers/hwtracing/coresight/coresight-tmc-etr.c

+110 −4
Original line number Diff line number Diff line
@@ -516,7 +516,7 @@ static void tmc_etr_sg_table_populate(struct etr_sg_table *etr_table) 
 * @size	- Total size of the data buffer

 * @pages	- Optional list of page virtual address

 */

static struct etr_sg_table __maybe_unused *

static struct etr_sg_table *

tmc_init_etr_sg_table(struct device *dev, int node,

		      unsigned long size, void **pages)

{
@@ -623,8 +623,86 @@ static const struct etr_buf_operations etr_flat_buf_ops = { 
	.get_data = tmc_etr_get_data_flat_buf,

};



/*

 * tmc_etr_alloc_sg_buf: Allocate an SG buf @etr_buf. Setup the parameters

 * appropriately.

 */

static int tmc_etr_alloc_sg_buf(struct tmc_drvdata *drvdata,

				struct etr_buf *etr_buf, int node,

				void **pages)

{

	struct etr_sg_table *etr_table;



	etr_table = tmc_init_etr_sg_table(drvdata->dev, node,

					  etr_buf->size, pages);

	if (IS_ERR(etr_table))

		return -ENOMEM;

	etr_buf->hwaddr = etr_table->hwaddr;

	etr_buf->mode = ETR_MODE_ETR_SG;

	etr_buf->private = etr_table;

	return 0;

}



static void tmc_etr_free_sg_buf(struct etr_buf *etr_buf)

{

	struct etr_sg_table *etr_table = etr_buf->private;



	if (etr_table) {

		tmc_free_sg_table(etr_table->sg_table);

		kfree(etr_table);

	}

}



static ssize_t tmc_etr_get_data_sg_buf(struct etr_buf *etr_buf, u64 offset,

				       size_t len, char **bufpp)

{

	struct etr_sg_table *etr_table = etr_buf->private;



	return tmc_sg_table_get_data(etr_table->sg_table, offset, len, bufpp);

}



static void tmc_etr_sync_sg_buf(struct etr_buf *etr_buf, u64 rrp, u64 rwp)

{

	long r_offset, w_offset;

	struct etr_sg_table *etr_table = etr_buf->private;

	struct tmc_sg_table *table = etr_table->sg_table;



	/* Convert hw address to offset in the buffer */

	r_offset = tmc_sg_get_data_page_offset(table, rrp);

	if (r_offset < 0) {

		dev_warn(table->dev,

			 "Unable to map RRP %llx to offset\n", rrp);

		etr_buf->len = 0;

		return;

	}



	w_offset = tmc_sg_get_data_page_offset(table, rwp);

	if (w_offset < 0) {

		dev_warn(table->dev,

			 "Unable to map RWP %llx to offset\n", rwp);

		etr_buf->len = 0;

		return;

	}



	etr_buf->offset = r_offset;

	if (etr_buf->full)

		etr_buf->len = etr_buf->size;

	else

		etr_buf->len = ((w_offset < r_offset) ? etr_buf->size : 0) +

				w_offset - r_offset;

	tmc_sg_table_sync_data_range(table, r_offset, etr_buf->len);

}



static const struct etr_buf_operations etr_sg_buf_ops = {

	.alloc = tmc_etr_alloc_sg_buf,

	.free = tmc_etr_free_sg_buf,

	.sync = tmc_etr_sync_sg_buf,

	.get_data = tmc_etr_get_data_sg_buf,

};



static const struct etr_buf_operations *etr_buf_ops[] = {

	[ETR_MODE_FLAT] = &etr_flat_buf_ops,

	[ETR_MODE_ETR_SG] = &etr_sg_buf_ops,

};



static inline int tmc_etr_mode_alloc_buf(int mode,
@@ -636,6 +714,7 @@ static inline int tmc_etr_mode_alloc_buf(int mode, 


	switch (mode) {

	case ETR_MODE_FLAT:

	case ETR_MODE_ETR_SG:

		rc = etr_buf_ops[mode]->alloc(drvdata, etr_buf, node, pages);

		if (!rc)

			etr_buf->ops = etr_buf_ops[mode];
@@ -657,17 +736,38 @@ static struct etr_buf *tmc_alloc_etr_buf(struct tmc_drvdata *drvdata, 
					 ssize_t size, int flags,

					 int node, void **pages)

{

	int rc = 0;

	int rc = -ENOMEM;

	bool has_etr_sg, has_iommu;

	struct etr_buf *etr_buf;



	has_etr_sg = tmc_etr_has_cap(drvdata, TMC_ETR_SG);

	has_iommu = iommu_get_domain_for_dev(drvdata->dev);



	etr_buf = kzalloc(sizeof(*etr_buf), GFP_KERNEL);

	if (!etr_buf)

		return ERR_PTR(-ENOMEM);



	etr_buf->size = size;



	/*

	 * If we have to use an existing list of pages, we cannot reliably

	 * use a contiguous DMA memory (even if we have an IOMMU). Otherwise,

	 * we use the contiguous DMA memory if at least one of the following

	 * conditions is true:

	 *  a) The ETR cannot use Scatter-Gather.

	 *  b) we have a backing IOMMU

	 *  c) The requested memory size is smaller (< 1M).

	 *

	 * Fallback to available mechanisms.

	 *

	 */

	if (!pages &&

	    (!has_etr_sg || has_iommu || size < SZ_1M))

		rc = tmc_etr_mode_alloc_buf(ETR_MODE_FLAT, drvdata,

					    etr_buf, node, pages);

	if (rc && has_etr_sg)

		rc = tmc_etr_mode_alloc_buf(ETR_MODE_ETR_SG, drvdata,

					    etr_buf, node, pages);

	if (rc) {

		kfree(etr_buf);

		return ERR_PTR(rc);
@@ -761,6 +861,12 @@ static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata) 
		axictl |= TMC_AXICTL_ARCACHE_OS;

	}



	if (etr_buf->mode == ETR_MODE_ETR_SG) {

		if (WARN_ON(!tmc_etr_has_cap(drvdata, TMC_ETR_SG)))

			return;

		axictl |= TMC_AXICTL_SCT_GAT_MODE;

	}



	writel_relaxed(axictl, drvdata->base + TMC_AXICTL);

	tmc_write_dba(drvdata, etr_buf->hwaddr);

	/*

drivers/hwtracing/coresight/coresight-tmc.h

+1 −0
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ enum tmc_mem_intf_width { 


enum etr_mode {

	ETR_MODE_FLAT,		/* Uses contiguous flat buffer */

	ETR_MODE_ETR_SG,	/* Uses in-built TMC ETR SG mechanism */

};



struct etr_buf_operations;

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