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Commit b0ffec3d authored by Sarangdhar Joshi's avatar Sarangdhar Joshi
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coresight: add support for byte counter for scatter gather feature 



Byte counter interrupt feature provides an interface to set byte counter
value and collect continuous trace data stream from userspace. Add support
to read this trace data stream when scatter gather feature is enabled for
TMC ETR configuration.

Change-Id: Ic755b7ae14b4bf13f7f28897ec8827476366eaf7
Signed-off-by: default avatarSarangdhar Joshi <spjoshi@codeaurora.org>
parent 22b9645b

drivers/coresight/coresight-tmc.c

+92 −4
Original line number Diff line number Diff line
@@ -1550,6 +1550,77 @@ static int tmc_etr_byte_cntr_open(struct inode *inode, struct file *file) 
	return 0;

}



static void tmc_etr_sg_read_pos(struct tmc_drvdata *drvdata, loff_t *ppos,

				size_t bytes, bool noirq, size_t *len,

				char **bufpp)

{

	uint32_t rwp, i = 0;

	uint32_t blk_num, sg_tbl_num, blk_num_loc, read_off;

	uint32_t *virt_pte, *virt_st_tbl;

	void *virt_blk;

	phys_addr_t phys_pte;

	int total_ents = DIV_ROUND_UP(drvdata->size, PAGE_SIZE);

	int ents_per_pg = PAGE_SIZE/sizeof(uint32_t);



	if (*len == 0)

		return;



	blk_num = *ppos / PAGE_SIZE;

	read_off = *ppos % PAGE_SIZE;



	virt_st_tbl = (uint32_t *)drvdata->vaddr;



	/* Compute table index and block entry index within that table */

	if (blk_num && (blk_num == (total_ents - 1)) &&

	    !(blk_num % (ents_per_pg - 1))) {

		sg_tbl_num = blk_num / ents_per_pg;

		blk_num_loc = ents_per_pg - 1;

	} else {

		sg_tbl_num = blk_num / (ents_per_pg - 1);

		blk_num_loc = blk_num % (ents_per_pg - 1);

	}



	for (i = 0; i < sg_tbl_num; i++) {

		virt_pte = virt_st_tbl + (ents_per_pg - 1);

		phys_pte = TMC_ETR_SG_ENT_TO_BLK(*virt_pte);

		virt_st_tbl = (uint32_t *)phys_to_virt(phys_pte);

	}



	virt_pte = virt_st_tbl + blk_num_loc;

	phys_pte = TMC_ETR_SG_ENT_TO_BLK(*virt_pte);

	virt_blk = phys_to_virt(phys_pte);



	*bufpp = virt_blk + read_off;



	if (noirq) {

		rwp = tmc_readl(drvdata, TMC_RWP);

		tmc_etr_sg_rwp_pos(drvdata, rwp);

		if (drvdata->sg_blk_num == blk_num &&

		    rwp >= (phys_pte + read_off))

			*len = rwp - phys_pte - read_off;

		else if (drvdata->sg_blk_num > blk_num)

			*len = PAGE_SIZE - read_off;

		else

			*len = bytes;

	} else {



		if (*len > (PAGE_SIZE - read_off))

			*len = PAGE_SIZE - read_off;



		if (*len >= (bytes - ((uint32_t)*ppos % bytes)))

			*len = bytes - ((uint32_t)*ppos % bytes);



		if ((*len + (uint32_t)*ppos) % bytes == 0)

			atomic_dec(&drvdata->byte_cntr_irq_cnt);

	}



	/*

	 * Invalidate cache range before reading. This will make sure that CPU

	 * reads latest contents from DDR

	 */

	dmac_inv_range((void *)(*bufpp), (void *)(*bufpp) + *len);

}



static void tmc_etr_read_bytes(struct tmc_drvdata *drvdata, loff_t *ppos,

			       size_t bytes, size_t *len)

{
@@ -1603,13 +1674,21 @@ static ssize_t tmc_etr_byte_cntr_read(struct file *file, char __user *data, 
			/* Read the last 'block' of data which might be needed

			 * to be read partially. If already read, return 0

			 */

			if (drvdata->memtype == TMC_ETR_MEM_TYPE_CONTIG)

				len = tmc_etr_flush_bytes(drvdata, ppos, bytes);

			else

				tmc_etr_sg_read_pos(drvdata, ppos, bytes,

						    true, &len, &bufp);

			if (!len)

				goto read_err0;

		} else {

			/* Keep reading until you reach the last block of data

			 */

			if (drvdata->memtype == TMC_ETR_MEM_TYPE_CONTIG)

				tmc_etr_read_bytes(drvdata, ppos, bytes, &len);

			else

				tmc_etr_sg_read_pos(drvdata, ppos, bytes,

						    false, &len, &bufp);

		}

	} else {

		if (!atomic_read(&drvdata->byte_cntr_irq_cnt)) {
@@ -1632,15 +1711,24 @@ static ssize_t tmc_etr_byte_cntr_read(struct file *file, char __user *data, 
		}

		if (!drvdata->byte_cntr_enable &&

		    !atomic_read(&drvdata->byte_cntr_irq_cnt)) {

			if (drvdata->memtype == TMC_ETR_MEM_TYPE_CONTIG)

				len = tmc_etr_flush_bytes(drvdata, ppos, bytes);

			else

				tmc_etr_sg_read_pos(drvdata, ppos, bytes,

						    true, &len, &bufp);

			if (!len) {

				ret = 0;

				goto read_err0;

			}

		} else {

			if (drvdata->memtype == TMC_ETR_MEM_TYPE_CONTIG)

				tmc_etr_read_bytes(drvdata, ppos, bytes, &len);

			else

				tmc_etr_sg_read_pos(drvdata, ppos, bytes,

						    false, &len, &bufp);

		}

	}



	if (copy_to_user(data, bufp, len)) {

		mutex_unlock(&drvdata->byte_cntr_lock);

		dev_dbg(drvdata->dev, "%s: copy_to_user failed\n", __func__);