Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1233 insertions, 0 deletions

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
new file mode 100644
index 000000000..9a3cb0755
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -0,0 +1,1233 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright(C) 2016 Linaro Limited. All rights reserved.
+ * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
+ */
+
+#include <linux/coresight.h>
+#include <linux/dma-mapping.h>
+#include <linux/iommu.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include "coresight-catu.h"
+#include "coresight-priv.h"
+#include "coresight-tmc.h"
+
+struct etr_flat_buf {
+	struct device	*dev;
+	dma_addr_t	daddr;
+	void		*vaddr;
+	size_t		size;
+};
+
+/*
+ * The TMC ETR SG has a page size of 4K. The SG table contains pointers
+ * to 4KB buffers. However, the OS may use a PAGE_SIZE different from
+ * 4K (i.e, 16KB or 64KB). This implies that a single OS page could
+ * contain more than one SG buffer and tables.
+ *
+ * A table entry has the following format:
+ *
+ * ---Bit31------------Bit4-------Bit1-----Bit0--
+ * |     Address[39:12]    | SBZ |  Entry Type  |
+ * ----------------------------------------------
+ *
+ * Address: Bits [39:12] of a physical page address. Bits [11:0] are
+ *	    always zero.
+ *
+ * Entry type:
+ *	b00 - Reserved.
+ *	b01 - Last entry in the tables, points to 4K page buffer.
+ *	b10 - Normal entry, points to 4K page buffer.
+ *	b11 - Link. The address points to the base of next table.
+ */
+
+typedef u32 sgte_t;
+
+#define ETR_SG_PAGE_SHIFT		12
+#define ETR_SG_PAGE_SIZE		(1UL << ETR_SG_PAGE_SHIFT)
+#define ETR_SG_PAGES_PER_SYSPAGE	(PAGE_SIZE / ETR_SG_PAGE_SIZE)
+#define ETR_SG_PTRS_PER_PAGE		(ETR_SG_PAGE_SIZE / sizeof(sgte_t))
+#define ETR_SG_PTRS_PER_SYSPAGE		(PAGE_SIZE / sizeof(sgte_t))
+
+#define ETR_SG_ET_MASK			0x3
+#define ETR_SG_ET_LAST			0x1
+#define ETR_SG_ET_NORMAL		0x2
+#define ETR_SG_ET_LINK			0x3
+
+#define ETR_SG_ADDR_SHIFT		4
+
+#define ETR_SG_ENTRY(addr, type) \
+	(sgte_t)((((addr) >> ETR_SG_PAGE_SHIFT) << ETR_SG_ADDR_SHIFT) | \
+		 (type & ETR_SG_ET_MASK))
+
+#define ETR_SG_ADDR(entry) \
+	(((dma_addr_t)(entry) >> ETR_SG_ADDR_SHIFT) << ETR_SG_PAGE_SHIFT)
+#define ETR_SG_ET(entry)		((entry) & ETR_SG_ET_MASK)
+
+/*
+ * struct etr_sg_table : ETR SG Table
+ * @sg_table:		Generic SG Table holding the data/table pages.
+ * @hwaddr:		hwaddress used by the TMC, which is the base
+ *			address of the table.
+ */
+struct etr_sg_table {
+	struct tmc_sg_table	*sg_table;
+	dma_addr_t		hwaddr;
+};
+
+/*
+ * tmc_etr_sg_table_entries: Total number of table entries required to map
+ * @nr_pages system pages.
+ *
+ * We need to map @nr_pages * ETR_SG_PAGES_PER_SYSPAGE data pages.
+ * Each TMC page can map (ETR_SG_PTRS_PER_PAGE - 1) buffer pointers,
+ * with the last entry pointing to another page of table entries.
+ * If we spill over to a new page for mapping 1 entry, we could as
+ * well replace the link entry of the previous page with the last entry.
+ */
+static inline unsigned long __attribute_const__
+tmc_etr_sg_table_entries(int nr_pages)
+{
+	unsigned long nr_sgpages = nr_pages * ETR_SG_PAGES_PER_SYSPAGE;
+	unsigned long nr_sglinks = nr_sgpages / (ETR_SG_PTRS_PER_PAGE - 1);
+	/*
+	 * If we spill over to a new page for 1 entry, we could as well
+	 * make it the LAST entry in the previous page, skipping the Link
+	 * address.
+	 */
+	if (nr_sglinks && (nr_sgpages % (ETR_SG_PTRS_PER_PAGE - 1) < 2))
+		nr_sglinks--;
+	return nr_sgpages + nr_sglinks;
+}
+
+/*
+ * tmc_pages_get_offset:  Go through all the pages in the tmc_pages
+ * and map the device address @addr to an offset within the virtual
+ * contiguous buffer.
+ */
+static long
+tmc_pages_get_offset(struct tmc_pages *tmc_pages, dma_addr_t addr)
+{
+	int i;
+	dma_addr_t page_start;
+
+	for (i = 0; i < tmc_pages->nr_pages; i++) {
+		page_start = tmc_pages->daddrs[i];
+		if (addr >= page_start && addr < (page_start + PAGE_SIZE))
+			return i * PAGE_SIZE + (addr - page_start);
+	}
+
+	return -EINVAL;
+}
+
+/*
+ * tmc_pages_free : Unmap and free the pages used by tmc_pages.
+ * If the pages were not allocated in tmc_pages_alloc(), we would
+ * simply drop the refcount.
+ */
+static void tmc_pages_free(struct tmc_pages *tmc_pages,
+			   struct device *dev, enum dma_data_direction dir)
+{
+	int i;
+
+	for (i = 0; i < tmc_pages->nr_pages; i++) {
+		if (tmc_pages->daddrs && tmc_pages->daddrs[i])
+			dma_unmap_page(dev, tmc_pages->daddrs[i],
+					 PAGE_SIZE, dir);
+		if (tmc_pages->pages && tmc_pages->pages[i])
+			__free_page(tmc_pages->pages[i]);
+	}
+
+	kfree(tmc_pages->pages);
+	kfree(tmc_pages->daddrs);
+	tmc_pages->pages = NULL;
+	tmc_pages->daddrs = NULL;
+	tmc_pages->nr_pages = 0;
+}
+
+/*
+ * tmc_pages_alloc : Allocate and map pages for a given @tmc_pages.
+ * If @pages is not NULL, the list of page virtual addresses are
+ * used as the data pages. The pages are then dma_map'ed for @dev
+ * with dma_direction @dir.
+ *
+ * Returns 0 upon success, else the error number.
+ */
+static int tmc_pages_alloc(struct tmc_pages *tmc_pages,
+			   struct device *dev, int node,
+			   enum dma_data_direction dir, void **pages)
+{
+	int i, nr_pages;
+	dma_addr_t paddr;
+	struct page *page;
+
+	nr_pages = tmc_pages->nr_pages;
+	tmc_pages->daddrs = kcalloc(nr_pages, sizeof(*tmc_pages->daddrs),
+					 GFP_KERNEL);
+	if (!tmc_pages->daddrs)
+		return -ENOMEM;
+	tmc_pages->pages = kcalloc(nr_pages, sizeof(*tmc_pages->pages),
+					 GFP_KERNEL);
+	if (!tmc_pages->pages) {
+		kfree(tmc_pages->daddrs);
+		tmc_pages->daddrs = NULL;
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < nr_pages; i++) {
+		if (pages && pages[i]) {
+			page = virt_to_page(pages[i]);
+			/* Hold a refcount on the page */
+			get_page(page);
+		} else {
+			page = alloc_pages_node(node,
+						GFP_KERNEL | __GFP_ZERO, 0);
+			if (!page)
+				goto err;
+		}
+		paddr = dma_map_page(dev, page, 0, PAGE_SIZE, dir);
+		if (dma_mapping_error(dev, paddr))
+			goto err;
+		tmc_pages->daddrs[i] = paddr;
+		tmc_pages->pages[i] = page;
+	}
+	return 0;
+err:
+	tmc_pages_free(tmc_pages, dev, dir);
+	return -ENOMEM;
+}
+
+static inline long
+tmc_sg_get_data_page_offset(struct tmc_sg_table *sg_table, dma_addr_t addr)
+{
+	return tmc_pages_get_offset(&sg_table->data_pages, addr);
+}
+
+static inline void tmc_free_table_pages(struct tmc_sg_table *sg_table)
+{
+	if (sg_table->table_vaddr)
+		vunmap(sg_table->table_vaddr);
+	tmc_pages_free(&sg_table->table_pages, sg_table->dev, DMA_TO_DEVICE);
+}
+
+static void tmc_free_data_pages(struct tmc_sg_table *sg_table)
+{
+	if (sg_table->data_vaddr)
+		vunmap(sg_table->data_vaddr);
+	tmc_pages_free(&sg_table->data_pages, sg_table->dev, DMA_FROM_DEVICE);
+}
+
+void tmc_free_sg_table(struct tmc_sg_table *sg_table)
+{
+	tmc_free_table_pages(sg_table);
+	tmc_free_data_pages(sg_table);
+}
+
+/*
+ * Alloc pages for the table. Since this will be used by the device,
+ * allocate the pages closer to the device (i.e, dev_to_node(dev)
+ * rather than the CPU node).
+ */
+static int tmc_alloc_table_pages(struct tmc_sg_table *sg_table)
+{
+	int rc;
+	struct tmc_pages *table_pages = &sg_table->table_pages;
+
+	rc = tmc_pages_alloc(table_pages, sg_table->dev,
+			     dev_to_node(sg_table->dev),
+			     DMA_TO_DEVICE, NULL);
+	if (rc)
+		return rc;
+	sg_table->table_vaddr = vmap(table_pages->pages,
+				     table_pages->nr_pages,
+				     VM_MAP,
+				     PAGE_KERNEL);
+	if (!sg_table->table_vaddr)
+		rc = -ENOMEM;
+	else
+		sg_table->table_daddr = table_pages->daddrs[0];
+	return rc;
+}
+
+static int tmc_alloc_data_pages(struct tmc_sg_table *sg_table, void **pages)
+{
+	int rc;
+
+	/* Allocate data pages on the node requested by the caller */
+	rc = tmc_pages_alloc(&sg_table->data_pages,
+			     sg_table->dev, sg_table->node,
+			     DMA_FROM_DEVICE, pages);
+	if (!rc) {
+		sg_table->data_vaddr = vmap(sg_table->data_pages.pages,
+					    sg_table->data_pages.nr_pages,
+					    VM_MAP,
+					    PAGE_KERNEL);
+		if (!sg_table->data_vaddr)
+			rc = -ENOMEM;
+	}
+	return rc;
+}
+
+/*
+ * tmc_alloc_sg_table: Allocate and setup dma pages for the TMC SG table
+ * and data buffers. TMC writes to the data buffers and reads from the SG
+ * Table pages.
+ *
+ * @dev		- Device to which page should be DMA mapped.
+ * @node	- Numa node for mem allocations
+ * @nr_tpages	- Number of pages for the table entries.
+ * @nr_dpages	- Number of pages for Data buffer.
+ * @pages	- Optional list of virtual address of pages.
+ */
+struct tmc_sg_table *tmc_alloc_sg_table(struct device *dev,
+					int node,
+					int nr_tpages,
+					int nr_dpages,
+					void **pages)
+{
+	long rc;
+	struct tmc_sg_table *sg_table;
+
+	sg_table = kzalloc(sizeof(*sg_table), GFP_KERNEL);
+	if (!sg_table)
+		return ERR_PTR(-ENOMEM);
+	sg_table->data_pages.nr_pages = nr_dpages;
+	sg_table->table_pages.nr_pages = nr_tpages;
+	sg_table->node = node;
+	sg_table->dev = dev;
+
+	rc  = tmc_alloc_data_pages(sg_table, pages);
+	if (!rc)
+		rc = tmc_alloc_table_pages(sg_table);
+	if (rc) {
+		tmc_free_sg_table(sg_table);
+		kfree(sg_table);
+		return ERR_PTR(rc);
+	}
+
+	return sg_table;
+}
+
+/*
+ * tmc_sg_table_sync_data_range: Sync the data buffer written
+ * by the device from @offset upto a @size bytes.
+ */
+void tmc_sg_table_sync_data_range(struct tmc_sg_table *table,
+				  u64 offset, u64 size)
+{
+	int i, index, start;
+	int npages = DIV_ROUND_UP(size, PAGE_SIZE);
+	struct device *dev = table->dev;
+	struct tmc_pages *data = &table->data_pages;
+
+	start = offset >> PAGE_SHIFT;
+	for (i = start; i < (start + npages); i++) {
+		index = i % data->nr_pages;
+		dma_sync_single_for_cpu(dev, data->daddrs[index],
+					PAGE_SIZE, DMA_FROM_DEVICE);
+	}
+}
+
+/* tmc_sg_sync_table: Sync the page table */
+void tmc_sg_table_sync_table(struct tmc_sg_table *sg_table)
+{
+	int i;
+	struct device *dev = sg_table->dev;
+	struct tmc_pages *table_pages = &sg_table->table_pages;
+
+	for (i = 0; i < table_pages->nr_pages; i++)
+		dma_sync_single_for_device(dev, table_pages->daddrs[i],
+					   PAGE_SIZE, DMA_TO_DEVICE);
+}
+
+/*
+ * tmc_sg_table_get_data: Get the buffer pointer for data @offset
+ * in the SG buffer. The @bufpp is updated to point to the buffer.
+ * Returns :
+ *	the length of linear data available at @offset.
+ *	or
+ *	<= 0 if no data is available.
+ */
+ssize_t tmc_sg_table_get_data(struct tmc_sg_table *sg_table,
+			      u64 offset, size_t len, char **bufpp)
+{
+	size_t size;
+	int pg_idx = offset >> PAGE_SHIFT;
+	int pg_offset = offset & (PAGE_SIZE - 1);
+	struct tmc_pages *data_pages = &sg_table->data_pages;
+
+	size = tmc_sg_table_buf_size(sg_table);
+	if (offset >= size)
+		return -EINVAL;
+
+	/* Make sure we don't go beyond the end */
+	len = (len < (size - offset)) ? len : size - offset;
+	/* Respect the page boundaries */
+	len = (len < (PAGE_SIZE - pg_offset)) ? len : (PAGE_SIZE - pg_offset);
+	if (len > 0)
+		*bufpp = page_address(data_pages->pages[pg_idx]) + pg_offset;
+	return len;
+}
+
+#ifdef ETR_SG_DEBUG
+/* Map a dma address to virtual address */
+static unsigned long
+tmc_sg_daddr_to_vaddr(struct tmc_sg_table *sg_table,
+		      dma_addr_t addr, bool table)
+{
+	long offset;
+	unsigned long base;
+	struct tmc_pages *tmc_pages;
+
+	if (table) {
+		tmc_pages = &sg_table->table_pages;
+		base = (unsigned long)sg_table->table_vaddr;
+	} else {
+		tmc_pages = &sg_table->data_pages;
+		base = (unsigned long)sg_table->data_vaddr;
+	}
+
+	offset = tmc_pages_get_offset(tmc_pages, addr);
+	if (offset < 0)
+		return 0;
+	return base + offset;
+}
+
+/* Dump the given sg_table */
+static void tmc_etr_sg_table_dump(struct etr_sg_table *etr_table)
+{
+	sgte_t *ptr;
+	int i = 0;
+	dma_addr_t addr;
+	struct tmc_sg_table *sg_table = etr_table->sg_table;
+
+	ptr = (sgte_t *)tmc_sg_daddr_to_vaddr(sg_table,
+					      etr_table->hwaddr, true);
+	while (ptr) {
+		addr = ETR_SG_ADDR(*ptr);
+		switch (ETR_SG_ET(*ptr)) {
+		case ETR_SG_ET_NORMAL:
+			dev_dbg(sg_table->dev,
+				"%05d: %p\t:[N] 0x%llx\n", i, ptr, addr);
+			ptr++;
+			break;
+		case ETR_SG_ET_LINK:
+			dev_dbg(sg_table->dev,
+				"%05d: *** %p\t:{L} 0x%llx ***\n",
+				 i, ptr, addr);
+			ptr = (sgte_t *)tmc_sg_daddr_to_vaddr(sg_table,
+							      addr, true);
+			break;
+		case ETR_SG_ET_LAST:
+			dev_dbg(sg_table->dev,
+				"%05d: ### %p\t:[L] 0x%llx ###\n",
+				 i, ptr, addr);
+			return;
+		default:
+			dev_dbg(sg_table->dev,
+				"%05d: xxx %p\t:[INVALID] 0x%llx xxx\n",
+				 i, ptr, addr);
+			return;
+		}
+		i++;
+	}
+	dev_dbg(sg_table->dev, "******* End of Table *****\n");
+}
+#else
+static inline void tmc_etr_sg_table_dump(struct etr_sg_table *etr_table) {}
+#endif
+
+/*
+ * Populate the SG Table page table entries from table/data
+ * pages allocated. Each Data page has ETR_SG_PAGES_PER_SYSPAGE SG pages.
+ * So does a Table page. So we keep track of indices of the tables
+ * in each system page and move the pointers accordingly.
+ */
+#define INC_IDX_ROUND(idx, size) ((idx) = ((idx) + 1) % (size))
+static void tmc_etr_sg_table_populate(struct etr_sg_table *etr_table)
+{
+	dma_addr_t paddr;
+	int i, type, nr_entries;
+	int tpidx = 0; /* index to the current system table_page */
+	int sgtidx = 0;	/* index to the sg_table within the current syspage */
+	int sgtentry = 0; /* the entry within the sg_table */
+	int dpidx = 0; /* index to the current system data_page */
+	int spidx = 0; /* index to the SG page within the current data page */
+	sgte_t *ptr; /* pointer to the table entry to fill */
+	struct tmc_sg_table *sg_table = etr_table->sg_table;
+	dma_addr_t *table_daddrs = sg_table->table_pages.daddrs;
+	dma_addr_t *data_daddrs = sg_table->data_pages.daddrs;
+
+	nr_entries = tmc_etr_sg_table_entries(sg_table->data_pages.nr_pages);
+	/*
+	 * Use the contiguous virtual address of the table to update entries.
+	 */
+	ptr = sg_table->table_vaddr;
+	/*
+	 * Fill all the entries, except the last entry to avoid special
+	 * checks within the loop.
+	 */
+	for (i = 0; i < nr_entries - 1; i++) {
+		if (sgtentry == ETR_SG_PTRS_PER_PAGE - 1) {
+			/*
+			 * Last entry in a sg_table page is a link address to
+			 * the next table page. If this sg_table is the last
+			 * one in the system page, it links to the first
+			 * sg_table in the next system page. Otherwise, it
+			 * links to the next sg_table page within the system
+			 * page.
+			 */
+			if (sgtidx == ETR_SG_PAGES_PER_SYSPAGE - 1) {
+				paddr = table_daddrs[tpidx + 1];
+			} else {
+				paddr = table_daddrs[tpidx] +
+					(ETR_SG_PAGE_SIZE * (sgtidx + 1));
+			}
+			type = ETR_SG_ET_LINK;
+		} else {
+			/*
+			 * Update the indices to the data_pages to point to the
+			 * next sg_page in the data buffer.
+			 */
+			type = ETR_SG_ET_NORMAL;
+			paddr = data_daddrs[dpidx] + spidx * ETR_SG_PAGE_SIZE;
+			if (!INC_IDX_ROUND(spidx, ETR_SG_PAGES_PER_SYSPAGE))
+				dpidx++;
+		}
+		*ptr++ = ETR_SG_ENTRY(paddr, type);
+		/*
+		 * Move to the next table pointer, moving the table page index
+		 * if necessary
+		 */
+		if (!INC_IDX_ROUND(sgtentry, ETR_SG_PTRS_PER_PAGE)) {
+			if (!INC_IDX_ROUND(sgtidx, ETR_SG_PAGES_PER_SYSPAGE))
+				tpidx++;
+		}
+	}
+
+	/* Set up the last entry, which is always a data pointer */
+	paddr = data_daddrs[dpidx] + spidx * ETR_SG_PAGE_SIZE;
+	*ptr++ = ETR_SG_ENTRY(paddr, ETR_SG_ET_LAST);
+}
+
+/*
+ * tmc_init_etr_sg_table: Allocate a TMC ETR SG table, data buffer of @size and
+ * populate the table.
+ *
+ * @dev		- Device pointer for the TMC
+ * @node	- NUMA node where the memory should be allocated
+ * @size	- Total size of the data buffer
+ * @pages	- Optional list of page virtual address
+ */
+static struct etr_sg_table *
+tmc_init_etr_sg_table(struct device *dev, int node,
+		      unsigned long size, void **pages)
+{
+	int nr_entries, nr_tpages;
+	int nr_dpages = size >> PAGE_SHIFT;
+	struct tmc_sg_table *sg_table;
+	struct etr_sg_table *etr_table;
+
+	etr_table = kzalloc(sizeof(*etr_table), GFP_KERNEL);
+	if (!etr_table)
+		return ERR_PTR(-ENOMEM);
+	nr_entries = tmc_etr_sg_table_entries(nr_dpages);
+	nr_tpages = DIV_ROUND_UP(nr_entries, ETR_SG_PTRS_PER_SYSPAGE);
+
+	sg_table = tmc_alloc_sg_table(dev, node, nr_tpages, nr_dpages, pages);
+	if (IS_ERR(sg_table)) {
+		kfree(etr_table);
+		return ERR_CAST(sg_table);
+	}
+
+	etr_table->sg_table = sg_table;
+	/* TMC should use table base address for DBA */
+	etr_table->hwaddr = sg_table->table_daddr;
+	tmc_etr_sg_table_populate(etr_table);
+	/* Sync the table pages for the HW */
+	tmc_sg_table_sync_table(sg_table);
+	tmc_etr_sg_table_dump(etr_table);
+
+	return etr_table;
+}
+
+/*
+ * tmc_etr_alloc_flat_buf: Allocate a contiguous DMA buffer.
+ */
+static int tmc_etr_alloc_flat_buf(struct tmc_drvdata *drvdata,
+				  struct etr_buf *etr_buf, int node,
+				  void **pages)
+{
+	struct etr_flat_buf *flat_buf;
+
+	/* We cannot reuse existing pages for flat buf */
+	if (pages)
+		return -EINVAL;
+
+	flat_buf = kzalloc(sizeof(*flat_buf), GFP_KERNEL);
+	if (!flat_buf)
+		return -ENOMEM;
+
+	flat_buf->vaddr = dma_alloc_coherent(drvdata->dev, etr_buf->size,
+					     &flat_buf->daddr, GFP_KERNEL);
+	if (!flat_buf->vaddr) {
+		kfree(flat_buf);
+		return -ENOMEM;
+	}
+
+	flat_buf->size = etr_buf->size;
+	flat_buf->dev = drvdata->dev;
+	etr_buf->hwaddr = flat_buf->daddr;
+	etr_buf->mode = ETR_MODE_FLAT;
+	etr_buf->private = flat_buf;
+	return 0;
+}
+
+static void tmc_etr_free_flat_buf(struct etr_buf *etr_buf)
+{
+	struct etr_flat_buf *flat_buf = etr_buf->private;
+
+	if (flat_buf && flat_buf->daddr)
+		dma_free_coherent(flat_buf->dev, flat_buf->size,
+				  flat_buf->vaddr, flat_buf->daddr);
+	kfree(flat_buf);
+}
+
+static void tmc_etr_sync_flat_buf(struct etr_buf *etr_buf, u64 rrp, u64 rwp)
+{
+	/*
+	 * Adjust the buffer to point to the beginning of the trace data
+	 * and update the available trace data.
+	 */
+	etr_buf->offset = rrp - etr_buf->hwaddr;
+	if (etr_buf->full)
+		etr_buf->len = etr_buf->size;
+	else
+		etr_buf->len = rwp - rrp;
+}
+
+static ssize_t tmc_etr_get_data_flat_buf(struct etr_buf *etr_buf,
+					 u64 offset, size_t len, char **bufpp)
+{
+	struct etr_flat_buf *flat_buf = etr_buf->private;
+
+	*bufpp = (char *)flat_buf->vaddr + offset;
+	/*
+	 * tmc_etr_buf_get_data already adjusts the length to handle
+	 * buffer wrapping around.
+	 */
+	return len;
+}
+
+static const struct etr_buf_operations etr_flat_buf_ops = {
+	.alloc = tmc_etr_alloc_flat_buf,
+	.free = tmc_etr_free_flat_buf,
+	.sync = tmc_etr_sync_flat_buf,
+	.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,
+};
+
+/*
+ * TMC ETR could be connected to a CATU device, which can provide address
+ * translation service. This is represented by the Output port of the TMC
+ * (ETR) connected to the input port of the CATU.
+ *
+ * Returns	: coresight_device ptr for the CATU device if a CATU is found.
+ *		: NULL otherwise.
+ */
+struct coresight_device *
+tmc_etr_get_catu_device(struct tmc_drvdata *drvdata)
+{
+	int i;
+	struct coresight_device *tmp, *etr = drvdata->csdev;
+
+	if (!IS_ENABLED(CONFIG_CORESIGHT_CATU))
+		return NULL;
+
+	for (i = 0; i < etr->nr_outport; i++) {
+		tmp = etr->conns[i].child_dev;
+		if (tmp && coresight_is_catu_device(tmp))
+			return tmp;
+	}
+
+	return NULL;
+}
+
+static inline void tmc_etr_enable_catu(struct tmc_drvdata *drvdata)
+{
+	struct coresight_device *catu = tmc_etr_get_catu_device(drvdata);
+
+	if (catu && helper_ops(catu)->enable)
+		helper_ops(catu)->enable(catu, drvdata->etr_buf);
+}
+
+static inline void tmc_etr_disable_catu(struct tmc_drvdata *drvdata)
+{
+	struct coresight_device *catu = tmc_etr_get_catu_device(drvdata);
+
+	if (catu && helper_ops(catu)->disable)
+		helper_ops(catu)->disable(catu, drvdata->etr_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,
+	[ETR_MODE_CATU] = IS_ENABLED(CONFIG_CORESIGHT_CATU)
+						? &etr_catu_buf_ops : NULL,
+};
+
+static inline int tmc_etr_mode_alloc_buf(int mode,
+					 struct tmc_drvdata *drvdata,
+					 struct etr_buf *etr_buf, int node,
+					 void **pages)
+{
+	int rc = -EINVAL;
+
+	switch (mode) {
+	case ETR_MODE_FLAT:
+	case ETR_MODE_ETR_SG:
+	case ETR_MODE_CATU:
+		if (etr_buf_ops[mode] && etr_buf_ops[mode]->alloc)
+			rc = etr_buf_ops[mode]->alloc(drvdata, etr_buf,
+						      node, pages);
+		if (!rc)
+			etr_buf->ops = etr_buf_ops[mode];
+		return rc;
+	default:
+		return -EINVAL;
+	}
+}
+
+/*
+ * tmc_alloc_etr_buf: Allocate a buffer use by ETR.
+ * @drvdata	: ETR device details.
+ * @size	: size of the requested buffer.
+ * @flags	: Required properties for the buffer.
+ * @node	: Node for memory allocations.
+ * @pages	: An optional list of pages.
+ */
+static struct etr_buf *tmc_alloc_etr_buf(struct tmc_drvdata *drvdata,
+					 ssize_t size, int flags,
+					 int node, void **pages)
+{
+	int rc = -ENOMEM;
+	bool has_etr_sg, has_iommu;
+	bool has_sg, has_catu;
+	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);
+	has_catu = !!tmc_etr_get_catu_device(drvdata);
+
+	has_sg = has_catu || has_etr_sg;
+
+	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_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 && has_catu)
+		rc = tmc_etr_mode_alloc_buf(ETR_MODE_CATU, drvdata,
+					    etr_buf, node, pages);
+	if (rc) {
+		kfree(etr_buf);
+		return ERR_PTR(rc);
+	}
+
+	dev_dbg(drvdata->dev, "allocated buffer of size %ldKB in mode %d\n",
+		(unsigned long)size >> 10, etr_buf->mode);
+	return etr_buf;
+}
+
+static void tmc_free_etr_buf(struct etr_buf *etr_buf)
+{
+	WARN_ON(!etr_buf->ops || !etr_buf->ops->free);
+	etr_buf->ops->free(etr_buf);
+	kfree(etr_buf);
+}
+
+/*
+ * tmc_etr_buf_get_data: Get the pointer the trace data at @offset
+ * with a maximum of @len bytes.
+ * Returns: The size of the linear data available @pos, with *bufpp
+ * updated to point to the buffer.
+ */
+static ssize_t tmc_etr_buf_get_data(struct etr_buf *etr_buf,
+				    u64 offset, size_t len, char **bufpp)
+{
+	/* Adjust the length to limit this transaction to end of buffer */
+	len = (len < (etr_buf->size - offset)) ? len : etr_buf->size - offset;
+
+	return etr_buf->ops->get_data(etr_buf, (u64)offset, len, bufpp);
+}
+
+static inline s64
+tmc_etr_buf_insert_barrier_packet(struct etr_buf *etr_buf, u64 offset)
+{
+	ssize_t len;
+	char *bufp;
+
+	len = tmc_etr_buf_get_data(etr_buf, offset,
+				   CORESIGHT_BARRIER_PKT_SIZE, &bufp);
+	if (WARN_ON(len < CORESIGHT_BARRIER_PKT_SIZE))
+		return -EINVAL;
+	coresight_insert_barrier_packet(bufp);
+	return offset + CORESIGHT_BARRIER_PKT_SIZE;
+}
+
+/*
+ * tmc_sync_etr_buf: Sync the trace buffer availability with drvdata.
+ * Makes sure the trace data is synced to the memory for consumption.
+ * @etr_buf->offset will hold the offset to the beginning of the trace data
+ * within the buffer, with @etr_buf->len bytes to consume.
+ */
+static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata)
+{
+	struct etr_buf *etr_buf = drvdata->etr_buf;
+	u64 rrp, rwp;
+	u32 status;
+
+	rrp = tmc_read_rrp(drvdata);
+	rwp = tmc_read_rwp(drvdata);
+	status = readl_relaxed(drvdata->base + TMC_STS);
+	etr_buf->full = status & TMC_STS_FULL;
+
+	WARN_ON(!etr_buf->ops || !etr_buf->ops->sync);
+
+	etr_buf->ops->sync(etr_buf, rrp, rwp);
+
+	/* Insert barrier packets at the beginning, if there was an overflow */
+	if (etr_buf->full)
+		tmc_etr_buf_insert_barrier_packet(etr_buf, etr_buf->offset);
+}
+
+static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata,
+			      struct etr_buf *etr_buf)
+{
+	u32 axictl, sts;
+
+	/* Callers should provide an appropriate buffer for use */
+	if (WARN_ON(!etr_buf || drvdata->etr_buf))
+		return;
+	drvdata->etr_buf = etr_buf;
+
+	/*
+	 * If this ETR is connected to a CATU, enable it before we turn
+	 * this on
+	 */
+	tmc_etr_enable_catu(drvdata);
+
+	CS_UNLOCK(drvdata->base);
+
+	/* Wait for TMCSReady bit to be set */
+	tmc_wait_for_tmcready(drvdata);
+
+	writel_relaxed(etr_buf->size / 4, drvdata->base + TMC_RSZ);
+	writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE);
+
+	axictl = readl_relaxed(drvdata->base + TMC_AXICTL);
+	axictl &= ~TMC_AXICTL_CLEAR_MASK;
+	axictl |= (TMC_AXICTL_PROT_CTL_B1 | TMC_AXICTL_WR_BURST_16);
+	axictl |= TMC_AXICTL_AXCACHE_OS;
+
+	if (tmc_etr_has_cap(drvdata, TMC_ETR_AXI_ARCACHE)) {
+		axictl &= ~TMC_AXICTL_ARCACHE_MASK;
+		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);
+	/*
+	 * If the TMC pointers must be programmed before the session,
+	 * we have to set it properly (i.e, RRP/RWP to base address and
+	 * STS to "not full").
+	 */
+	if (tmc_etr_has_cap(drvdata, TMC_ETR_SAVE_RESTORE)) {
+		tmc_write_rrp(drvdata, etr_buf->hwaddr);
+		tmc_write_rwp(drvdata, etr_buf->hwaddr);
+		sts = readl_relaxed(drvdata->base + TMC_STS) & ~TMC_STS_FULL;
+		writel_relaxed(sts, drvdata->base + TMC_STS);
+	}
+
+	writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI |
+		       TMC_FFCR_FON_FLIN | TMC_FFCR_FON_TRIG_EVT |
+		       TMC_FFCR_TRIGON_TRIGIN,
+		       drvdata->base + TMC_FFCR);
+	writel_relaxed(drvdata->trigger_cntr, drvdata->base + TMC_TRG);
+	tmc_enable_hw(drvdata);
+
+	CS_LOCK(drvdata->base);
+}
+
+/*
+ * Return the available trace data in the buffer (starts at etr_buf->offset,
+ * limited by etr_buf->len) from @pos, with a maximum limit of @len,
+ * also updating the @bufpp on where to find it. Since the trace data
+ * starts at anywhere in the buffer, depending on the RRP, we adjust the
+ * @len returned to handle buffer wrapping around.
+ *
+ * We are protected here by drvdata->reading != 0, which ensures the
+ * sysfs_buf stays alive.
+ */
+ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata,
+				loff_t pos, size_t len, char **bufpp)
+{
+	s64 offset;
+	ssize_t actual = len;
+	struct etr_buf *etr_buf = drvdata->sysfs_buf;
+
+	if (pos + actual > etr_buf->len)
+		actual = etr_buf->len - pos;
+	if (actual <= 0)
+		return actual;
+
+	/* Compute the offset from which we read the data */
+	offset = etr_buf->offset + pos;
+	if (offset >= etr_buf->size)
+		offset -= etr_buf->size;
+	return tmc_etr_buf_get_data(etr_buf, offset, actual, bufpp);
+}
+
+static struct etr_buf *
+tmc_etr_setup_sysfs_buf(struct tmc_drvdata *drvdata)
+{
+	return tmc_alloc_etr_buf(drvdata, drvdata->size,
+				 0, cpu_to_node(0), NULL);
+}
+
+static void
+tmc_etr_free_sysfs_buf(struct etr_buf *buf)
+{
+	if (buf)
+		tmc_free_etr_buf(buf);
+}
+
+static void tmc_etr_sync_sysfs_buf(struct tmc_drvdata *drvdata)
+{
+	struct etr_buf *etr_buf = drvdata->etr_buf;
+
+	if (WARN_ON(drvdata->sysfs_buf != etr_buf)) {
+		tmc_etr_free_sysfs_buf(drvdata->sysfs_buf);
+		drvdata->sysfs_buf = NULL;
+	} else {
+		tmc_sync_etr_buf(drvdata);
+	}
+}
+
+static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
+{
+	CS_UNLOCK(drvdata->base);
+
+	tmc_flush_and_stop(drvdata);
+	/*
+	 * When operating in sysFS mode the content of the buffer needs to be
+	 * read before the TMC is disabled.
+	 */
+	if (drvdata->mode == CS_MODE_SYSFS)
+		tmc_etr_sync_sysfs_buf(drvdata);
+
+	tmc_disable_hw(drvdata);
+
+	CS_LOCK(drvdata->base);
+
+	/* Disable CATU device if this ETR is connected to one */
+	tmc_etr_disable_catu(drvdata);
+	/* Reset the ETR buf used by hardware */
+	drvdata->etr_buf = NULL;
+}
+
+static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
+{
+	int ret = 0;
+	unsigned long flags;
+	struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+	struct etr_buf *sysfs_buf = NULL, *new_buf = NULL, *free_buf = NULL;
+
+	/*
+	 * If we are enabling the ETR from disabled state, we need to make
+	 * sure we have a buffer with the right size. The etr_buf is not reset
+	 * immediately after we stop the tracing in SYSFS mode as we wait for
+	 * the user to collect the data. We may be able to reuse the existing
+	 * buffer, provided the size matches. Any allocation has to be done
+	 * with the lock released.
+	 */
+	spin_lock_irqsave(&drvdata->spinlock, flags);
+	sysfs_buf = READ_ONCE(drvdata->sysfs_buf);
+	if (!sysfs_buf || (sysfs_buf->size != drvdata->size)) {
+		spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+		/* Allocate memory with the locks released */
+		free_buf = new_buf = tmc_etr_setup_sysfs_buf(drvdata);
+		if (IS_ERR(new_buf))
+			return PTR_ERR(new_buf);
+
+		/* Let's try again */
+		spin_lock_irqsave(&drvdata->spinlock, flags);
+	}
+
+	if (drvdata->reading || drvdata->mode == CS_MODE_PERF) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	/*
+	 * In sysFS mode we can have multiple writers per sink.  Since this
+	 * sink is already enabled no memory is needed and the HW need not be
+	 * touched, even if the buffer size has changed.
+	 */
+	if (drvdata->mode == CS_MODE_SYSFS)
+		goto out;
+
+	/*
+	 * If we don't have a buffer or it doesn't match the requested size,
+	 * use the buffer allocated above. Otherwise reuse the existing buffer.
+	 */
+	sysfs_buf = READ_ONCE(drvdata->sysfs_buf);
+	if (!sysfs_buf || (new_buf && sysfs_buf->size != new_buf->size)) {
+		free_buf = sysfs_buf;
+		drvdata->sysfs_buf = new_buf;
+	}
+
+	drvdata->mode = CS_MODE_SYSFS;
+	tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf);
+out:
+	spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+	/* Free memory outside the spinlock if need be */
+	if (free_buf)
+		tmc_etr_free_sysfs_buf(free_buf);
+
+	if (!ret)
+		dev_info(drvdata->dev, "TMC-ETR enabled\n");
+
+	return ret;
+}
+
+static int tmc_enable_etr_sink_perf(struct coresight_device *csdev)
+{
+	/* We don't support perf mode yet ! */
+	return -EINVAL;
+}
+
+static int tmc_enable_etr_sink(struct coresight_device *csdev, u32 mode)
+{
+	switch (mode) {
+	case CS_MODE_SYSFS:
+		return tmc_enable_etr_sink_sysfs(csdev);
+	case CS_MODE_PERF:
+		return tmc_enable_etr_sink_perf(csdev);
+	}
+
+	/* We shouldn't be here */
+	return -EINVAL;
+}
+
+static void tmc_disable_etr_sink(struct coresight_device *csdev)
+{
+	unsigned long flags;
+	struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	spin_lock_irqsave(&drvdata->spinlock, flags);
+	if (drvdata->reading) {
+		spin_unlock_irqrestore(&drvdata->spinlock, flags);
+		return;
+	}
+
+	/* Disable the TMC only if it needs to */
+	if (drvdata->mode != CS_MODE_DISABLED) {
+		tmc_etr_disable_hw(drvdata);
+		drvdata->mode = CS_MODE_DISABLED;
+	}
+
+	spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+	dev_info(drvdata->dev, "TMC-ETR disabled\n");
+}
+
+static const struct coresight_ops_sink tmc_etr_sink_ops = {
+	.enable		= tmc_enable_etr_sink,
+	.disable	= tmc_disable_etr_sink,
+};
+
+const struct coresight_ops tmc_etr_cs_ops = {
+	.sink_ops	= &tmc_etr_sink_ops,
+};
+
+int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
+{
+	int ret = 0;
+	unsigned long flags;
+
+	/* config types are set a boot time and never change */
+	if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
+		return -EINVAL;
+
+	spin_lock_irqsave(&drvdata->spinlock, flags);
+	if (drvdata->reading) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	/* Don't interfere if operated from Perf */
+	if (drvdata->mode == CS_MODE_PERF) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* If sysfs_buf is NULL the trace data has been read already */
+	if (!drvdata->sysfs_buf) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Disable the TMC if we are trying to read from a running session */
+	if (drvdata->mode == CS_MODE_SYSFS)
+		tmc_etr_disable_hw(drvdata);
+
+	drvdata->reading = true;
+out:
+	spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+	return ret;
+}
+
+int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
+{
+	unsigned long flags;
+	struct etr_buf *sysfs_buf = NULL;
+
+	/* config types are set a boot time and never change */
+	if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
+		return -EINVAL;
+
+	spin_lock_irqsave(&drvdata->spinlock, flags);
+
+	/* RE-enable the TMC if need be */
+	if (drvdata->mode == CS_MODE_SYSFS) {
+		/*
+		 * The trace run will continue with the same allocated trace
+		 * buffer. Since the tracer is still enabled drvdata::buf can't
+		 * be NULL.
+		 */
+		tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf);
+	} else {
+		/*
+		 * The ETR is not tracing and the buffer was just read.
+		 * As such prepare to free the trace buffer.
+		 */
+		sysfs_buf = drvdata->sysfs_buf;
+		drvdata->sysfs_buf = NULL;
+	}
+
+	drvdata->reading = false;
+	spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+	/* Free allocated memory out side of the spinlock */
+	if (sysfs_buf)
+		tmc_etr_free_sysfs_buf(sysfs_buf);
+
+	return 0;
+}