diff options
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-tmc-etr.c')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc-etr.c | 1764 |
1 files changed, 1764 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..ae2dd0c88 --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -0,0 +1,1764 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright(C) 2016 Linaro Limited. All rights reserved. + * Author: Mathieu Poirier <mathieu.poirier@linaro.org> + */ + +#include <linux/atomic.h> +#include <linux/coresight.h> +#include <linux/dma-mapping.h> +#include <linux/iommu.h> +#include <linux/idr.h> +#include <linux/mutex.h> +#include <linux/refcount.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/vmalloc.h> +#include "coresight-catu.h" +#include "coresight-etm-perf.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; +}; + +/* + * etr_perf_buffer - Perf buffer used for ETR + * @drvdata - The ETR drvdaga this buffer has been allocated for. + * @etr_buf - Actual buffer used by the ETR + * @pid - The PID this etr_perf_buffer belongs to. + * @snaphost - Perf session mode + * @head - handle->head at the beginning of the session. + * @nr_pages - Number of pages in the ring buffer. + * @pages - Array of Pages in the ring buffer. + */ +struct etr_perf_buffer { + struct tmc_drvdata *drvdata; + struct etr_buf *etr_buf; + pid_t pid; + bool snapshot; + unsigned long head; + int nr_pages; + void **pages; +}; + +/* Convert the perf index to an offset within the ETR buffer */ +#define PERF_IDX2OFF(idx, buf) \ + ((idx) % ((unsigned long)(buf)->nr_pages << PAGE_SHIFT)) + +/* Lower limit for ETR hardware buffer */ +#define TMC_ETR_PERF_MIN_BUF_SIZE SZ_1M + +/* + * 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; + struct device *real_dev = dev->parent; + + for (i = 0; i < tmc_pages->nr_pages; i++) { + if (tmc_pages->daddrs && tmc_pages->daddrs[i]) + dma_unmap_page(real_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; + struct device *real_dev = dev->parent; + + 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(real_dev, page, 0, PAGE_SIZE, dir); + if (dma_mapping_error(real_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); +} +EXPORT_SYMBOL_GPL(tmc_free_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 - Coresight 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; +} +EXPORT_SYMBOL_GPL(tmc_alloc_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 *real_dev = table->dev->parent; + 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(real_dev, data->daddrs[index], + PAGE_SIZE, DMA_FROM_DEVICE); + } +} +EXPORT_SYMBOL_GPL(tmc_sg_table_sync_data_range); + +/* tmc_sg_sync_table: Sync the page table */ +void tmc_sg_table_sync_table(struct tmc_sg_table *sg_table) +{ + int i; + struct device *real_dev = sg_table->dev->parent; + struct tmc_pages *table_pages = &sg_table->table_pages; + + for (i = 0; i < table_pages->nr_pages; i++) + dma_sync_single_for_device(real_dev, table_pages->daddrs[i], + PAGE_SIZE, DMA_TO_DEVICE); +} +EXPORT_SYMBOL_GPL(tmc_sg_table_sync_table); + +/* + * 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; +} +EXPORT_SYMBOL_GPL(tmc_sg_table_get_data); + +#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; + struct device *real_dev = drvdata->csdev->dev.parent; + + /* 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(real_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->csdev->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) { + struct device *real_dev = flat_buf->dev->parent; + + dma_free_coherent(real_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; + struct device *dev = &drvdata->csdev->dev; + + etr_table = tmc_init_etr_sg_table(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->pdata->nr_outport; i++) { + tmp = etr->pdata->conns[i].child_dev; + if (tmp && coresight_is_catu_device(tmp)) + return tmp; + } + + return NULL; +} +EXPORT_SYMBOL_GPL(tmc_etr_get_catu_device); + +static inline int tmc_etr_enable_catu(struct tmc_drvdata *drvdata, + struct etr_buf *etr_buf) +{ + struct coresight_device *catu = tmc_etr_get_catu_device(drvdata); + + if (catu && helper_ops(catu)->enable) + return helper_ops(catu)->enable(catu, etr_buf); + return 0; +} + +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] = NULL, +}; + +void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu) +{ + etr_buf_ops[ETR_MODE_CATU] = catu; +} +EXPORT_SYMBOL_GPL(tmc_etr_set_catu_ops); + +void tmc_etr_remove_catu_ops(void) +{ + etr_buf_ops[ETR_MODE_CATU] = NULL; +} +EXPORT_SYMBOL_GPL(tmc_etr_remove_catu_ops); + +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; + struct device *dev = &drvdata->csdev->dev; + + has_etr_sg = tmc_etr_has_cap(drvdata, TMC_ETR_SG); + has_iommu = iommu_get_domain_for_dev(dev->parent); + 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); + } + + refcount_set(&etr_buf->refcount, 1); + dev_dbg(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 < 0 || 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); + + /* + * If there were memory errors in the session, truncate the + * buffer. + */ + if (WARN_ON_ONCE(status & TMC_STS_MEMERR)) { + dev_dbg(&drvdata->csdev->dev, + "tmc memory error detected, truncating buffer\n"); + etr_buf->len = 0; + etr_buf->full = 0; + return; + } + + etr_buf->full = status & TMC_STS_FULL; + + WARN_ON(!etr_buf->ops || !etr_buf->ops->sync); + + etr_buf->ops->sync(etr_buf, rrp, rwp); +} + +static void __tmc_etr_enable_hw(struct tmc_drvdata *drvdata) +{ + u32 axictl, sts; + struct etr_buf *etr_buf = drvdata->etr_buf; + + 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) + 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); +} + +static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata, + struct etr_buf *etr_buf) +{ + int rc; + + /* Callers should provide an appropriate buffer for use */ + if (WARN_ON(!etr_buf)) + return -EINVAL; + + if ((etr_buf->mode == ETR_MODE_ETR_SG) && + WARN_ON(!tmc_etr_has_cap(drvdata, TMC_ETR_SG))) + return -EINVAL; + + if (WARN_ON(drvdata->etr_buf)) + return -EBUSY; + + /* + * If this ETR is connected to a CATU, enable it before we turn + * this on. + */ + rc = tmc_etr_enable_catu(drvdata, etr_buf); + if (rc) + return rc; + rc = coresight_claim_device(drvdata->base); + if (!rc) { + drvdata->etr_buf = etr_buf; + __tmc_etr_enable_hw(drvdata); + } + + return rc; +} + +/* + * 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); + /* + * 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_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); + +} + +void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) +{ + __tmc_etr_disable_hw(drvdata); + /* Disable CATU device if this ETR is connected to one */ + tmc_etr_disable_catu(drvdata); + coresight_disclaim_device(drvdata->base); + /* 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) { + atomic_inc(csdev->refcnt); + 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; + } + + ret = tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf); + if (!ret) { + drvdata->mode = CS_MODE_SYSFS; + atomic_inc(csdev->refcnt); + } +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_dbg(&csdev->dev, "TMC-ETR enabled\n"); + + return ret; +} + +/* + * alloc_etr_buf: Allocate ETR buffer for use by perf. + * The size of the hardware buffer is dependent on the size configured + * via sysfs and the perf ring buffer size. We prefer to allocate the + * largest possible size, scaling down the size by half until it + * reaches a minimum limit (1M), beyond which we give up. + */ +static struct etr_buf * +alloc_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event, + int nr_pages, void **pages, bool snapshot) +{ + int node; + struct etr_buf *etr_buf; + unsigned long size; + + node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu); + /* + * Try to match the perf ring buffer size if it is larger + * than the size requested via sysfs. + */ + if ((nr_pages << PAGE_SHIFT) > drvdata->size) { + etr_buf = tmc_alloc_etr_buf(drvdata, ((ssize_t)nr_pages << PAGE_SHIFT), + 0, node, NULL); + if (!IS_ERR(etr_buf)) + goto done; + } + + /* + * Else switch to configured size for this ETR + * and scale down until we hit the minimum limit. + */ + size = drvdata->size; + do { + etr_buf = tmc_alloc_etr_buf(drvdata, size, 0, node, NULL); + if (!IS_ERR(etr_buf)) + goto done; + size /= 2; + } while (size >= TMC_ETR_PERF_MIN_BUF_SIZE); + + return ERR_PTR(-ENOMEM); + +done: + return etr_buf; +} + +static struct etr_buf * +get_perf_etr_buf_cpu_wide(struct tmc_drvdata *drvdata, + struct perf_event *event, int nr_pages, + void **pages, bool snapshot) +{ + int ret; + pid_t pid = task_pid_nr(event->owner); + struct etr_buf *etr_buf; + +retry: + /* + * An etr_perf_buffer is associated with an event and holds a reference + * to the AUX ring buffer that was created for that event. In CPU-wide + * N:1 mode multiple events (one per CPU), each with its own AUX ring + * buffer, share a sink. As such an etr_perf_buffer is created for each + * event but a single etr_buf associated with the ETR is shared between + * them. The last event in a trace session will copy the content of the + * etr_buf to its AUX ring buffer. Ring buffer associated to other + * events are simply not used an freed as events are destoyed. We still + * need to allocate a ring buffer for each event since we don't know + * which event will be last. + */ + + /* + * The first thing to do here is check if an etr_buf has already been + * allocated for this session. If so it is shared with this event, + * otherwise it is created. + */ + mutex_lock(&drvdata->idr_mutex); + etr_buf = idr_find(&drvdata->idr, pid); + if (etr_buf) { + refcount_inc(&etr_buf->refcount); + mutex_unlock(&drvdata->idr_mutex); + return etr_buf; + } + + /* If we made it here no buffer has been allocated, do so now. */ + mutex_unlock(&drvdata->idr_mutex); + + etr_buf = alloc_etr_buf(drvdata, event, nr_pages, pages, snapshot); + if (IS_ERR(etr_buf)) + return etr_buf; + + /* Now that we have a buffer, add it to the IDR. */ + mutex_lock(&drvdata->idr_mutex); + ret = idr_alloc(&drvdata->idr, etr_buf, pid, pid + 1, GFP_KERNEL); + mutex_unlock(&drvdata->idr_mutex); + + /* Another event with this session ID has allocated this buffer. */ + if (ret == -ENOSPC) { + tmc_free_etr_buf(etr_buf); + goto retry; + } + + /* The IDR can't allocate room for a new session, abandon ship. */ + if (ret == -ENOMEM) { + tmc_free_etr_buf(etr_buf); + return ERR_PTR(ret); + } + + + return etr_buf; +} + +static struct etr_buf * +get_perf_etr_buf_per_thread(struct tmc_drvdata *drvdata, + struct perf_event *event, int nr_pages, + void **pages, bool snapshot) +{ + /* + * In per-thread mode the etr_buf isn't shared, so just go ahead + * with memory allocation. + */ + return alloc_etr_buf(drvdata, event, nr_pages, pages, snapshot); +} + +static struct etr_buf * +get_perf_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event, + int nr_pages, void **pages, bool snapshot) +{ + if (event->cpu == -1) + return get_perf_etr_buf_per_thread(drvdata, event, nr_pages, + pages, snapshot); + + return get_perf_etr_buf_cpu_wide(drvdata, event, nr_pages, + pages, snapshot); +} + +static struct etr_perf_buffer * +tmc_etr_setup_perf_buf(struct tmc_drvdata *drvdata, struct perf_event *event, + int nr_pages, void **pages, bool snapshot) +{ + int node; + struct etr_buf *etr_buf; + struct etr_perf_buffer *etr_perf; + + node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu); + + etr_perf = kzalloc_node(sizeof(*etr_perf), GFP_KERNEL, node); + if (!etr_perf) + return ERR_PTR(-ENOMEM); + + etr_buf = get_perf_etr_buf(drvdata, event, nr_pages, pages, snapshot); + if (!IS_ERR(etr_buf)) + goto done; + + kfree(etr_perf); + return ERR_PTR(-ENOMEM); + +done: + /* + * Keep a reference to the ETR this buffer has been allocated for + * in order to have access to the IDR in tmc_free_etr_buffer(). + */ + etr_perf->drvdata = drvdata; + etr_perf->etr_buf = etr_buf; + + return etr_perf; +} + + +static void *tmc_alloc_etr_buffer(struct coresight_device *csdev, + struct perf_event *event, void **pages, + int nr_pages, bool snapshot) +{ + struct etr_perf_buffer *etr_perf; + struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + etr_perf = tmc_etr_setup_perf_buf(drvdata, event, + nr_pages, pages, snapshot); + if (IS_ERR(etr_perf)) { + dev_dbg(&csdev->dev, "Unable to allocate ETR buffer\n"); + return NULL; + } + + etr_perf->pid = task_pid_nr(event->owner); + etr_perf->snapshot = snapshot; + etr_perf->nr_pages = nr_pages; + etr_perf->pages = pages; + + return etr_perf; +} + +static void tmc_free_etr_buffer(void *config) +{ + struct etr_perf_buffer *etr_perf = config; + struct tmc_drvdata *drvdata = etr_perf->drvdata; + struct etr_buf *buf, *etr_buf = etr_perf->etr_buf; + + if (!etr_buf) + goto free_etr_perf_buffer; + + mutex_lock(&drvdata->idr_mutex); + /* If we are not the last one to use the buffer, don't touch it. */ + if (!refcount_dec_and_test(&etr_buf->refcount)) { + mutex_unlock(&drvdata->idr_mutex); + goto free_etr_perf_buffer; + } + + /* We are the last one, remove from the IDR and free the buffer. */ + buf = idr_remove(&drvdata->idr, etr_perf->pid); + mutex_unlock(&drvdata->idr_mutex); + + /* + * Something went very wrong if the buffer associated with this ID + * is not the same in the IDR. Leak to avoid use after free. + */ + if (buf && WARN_ON(buf != etr_buf)) + goto free_etr_perf_buffer; + + tmc_free_etr_buf(etr_perf->etr_buf); + +free_etr_perf_buffer: + kfree(etr_perf); +} + +/* + * tmc_etr_sync_perf_buffer: Copy the actual trace data from the hardware + * buffer to the perf ring buffer. + */ +static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf, + unsigned long src_offset, + unsigned long to_copy) +{ + long bytes; + long pg_idx, pg_offset; + unsigned long head = etr_perf->head; + char **dst_pages, *src_buf; + struct etr_buf *etr_buf = etr_perf->etr_buf; + + head = etr_perf->head; + pg_idx = head >> PAGE_SHIFT; + pg_offset = head & (PAGE_SIZE - 1); + dst_pages = (char **)etr_perf->pages; + + while (to_copy > 0) { + /* + * In one iteration, we can copy minimum of : + * 1) what is available in the source buffer, + * 2) what is available in the source buffer, before it + * wraps around. + * 3) what is available in the destination page. + * in one iteration. + */ + if (src_offset >= etr_buf->size) + src_offset -= etr_buf->size; + bytes = tmc_etr_buf_get_data(etr_buf, src_offset, to_copy, + &src_buf); + if (WARN_ON_ONCE(bytes <= 0)) + break; + bytes = min(bytes, (long)(PAGE_SIZE - pg_offset)); + + memcpy(dst_pages[pg_idx] + pg_offset, src_buf, bytes); + + to_copy -= bytes; + + /* Move destination pointers */ + pg_offset += bytes; + if (pg_offset == PAGE_SIZE) { + pg_offset = 0; + if (++pg_idx == etr_perf->nr_pages) + pg_idx = 0; + } + + /* Move source pointers */ + src_offset += bytes; + } +} + +/* + * tmc_update_etr_buffer : Update the perf ring buffer with the + * available trace data. We use software double buffering at the moment. + * + * TODO: Add support for reusing the perf ring buffer. + */ +static unsigned long +tmc_update_etr_buffer(struct coresight_device *csdev, + struct perf_output_handle *handle, + void *config) +{ + bool lost = false; + unsigned long flags, offset, size = 0; + struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + struct etr_perf_buffer *etr_perf = config; + struct etr_buf *etr_buf = etr_perf->etr_buf; + + spin_lock_irqsave(&drvdata->spinlock, flags); + + /* Don't do anything if another tracer is using this sink */ + if (atomic_read(csdev->refcnt) != 1) { + spin_unlock_irqrestore(&drvdata->spinlock, flags); + goto out; + } + + if (WARN_ON(drvdata->perf_buf != etr_buf)) { + lost = true; + spin_unlock_irqrestore(&drvdata->spinlock, flags); + goto out; + } + + CS_UNLOCK(drvdata->base); + + tmc_flush_and_stop(drvdata); + tmc_sync_etr_buf(drvdata); + + CS_LOCK(drvdata->base); + spin_unlock_irqrestore(&drvdata->spinlock, flags); + + lost = etr_buf->full; + offset = etr_buf->offset; + size = etr_buf->len; + + /* + * The ETR buffer may be bigger than the space available in the + * perf ring buffer (handle->size). If so advance the offset so that we + * get the latest trace data. In snapshot mode none of that matters + * since we are expected to clobber stale data in favour of the latest + * traces. + */ + if (!etr_perf->snapshot && size > handle->size) { + u32 mask = tmc_get_memwidth_mask(drvdata); + + /* + * Make sure the new size is aligned in accordance with the + * requirement explained in function tmc_get_memwidth_mask(). + */ + size = handle->size & mask; + offset = etr_buf->offset + etr_buf->len - size; + + if (offset >= etr_buf->size) + offset -= etr_buf->size; + lost = true; + } + + /* Insert barrier packets at the beginning, if there was an overflow */ + if (lost) + tmc_etr_buf_insert_barrier_packet(etr_buf, offset); + tmc_etr_sync_perf_buffer(etr_perf, offset, size); + + /* + * In snapshot mode we simply increment the head by the number of byte + * that were written. User space function cs_etm_find_snapshot() will + * figure out how many bytes to get from the AUX buffer based on the + * position of the head. + */ + if (etr_perf->snapshot) + handle->head += size; +out: + /* + * Don't set the TRUNCATED flag in snapshot mode because 1) the + * captured buffer is expected to be truncated and 2) a full buffer + * prevents the event from being re-enabled by the perf core, + * resulting in stale data being send to user space. + */ + if (!etr_perf->snapshot && lost) + perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); + return size; +} + +static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data) +{ + int rc = 0; + pid_t pid; + unsigned long flags; + struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + struct perf_output_handle *handle = data; + struct etr_perf_buffer *etr_perf = etm_perf_sink_config(handle); + + spin_lock_irqsave(&drvdata->spinlock, flags); + /* Don't use this sink if it is already claimed by sysFS */ + if (drvdata->mode == CS_MODE_SYSFS) { + rc = -EBUSY; + goto unlock_out; + } + + if (WARN_ON(!etr_perf || !etr_perf->etr_buf)) { + rc = -EINVAL; + goto unlock_out; + } + + /* Get a handle on the pid of the process to monitor */ + pid = etr_perf->pid; + + /* Do not proceed if this device is associated with another session */ + if (drvdata->pid != -1 && drvdata->pid != pid) { + rc = -EBUSY; + goto unlock_out; + } + + etr_perf->head = PERF_IDX2OFF(handle->head, etr_perf); + + /* + * No HW configuration is needed if the sink is already in + * use for this session. + */ + if (drvdata->pid == pid) { + atomic_inc(csdev->refcnt); + goto unlock_out; + } + + rc = tmc_etr_enable_hw(drvdata, etr_perf->etr_buf); + if (!rc) { + /* Associate with monitored process. */ + drvdata->pid = pid; + drvdata->mode = CS_MODE_PERF; + drvdata->perf_buf = etr_perf->etr_buf; + atomic_inc(csdev->refcnt); + } + +unlock_out: + spin_unlock_irqrestore(&drvdata->spinlock, flags); + return rc; +} + +static int tmc_enable_etr_sink(struct coresight_device *csdev, + u32 mode, void *data) +{ + switch (mode) { + case CS_MODE_SYSFS: + return tmc_enable_etr_sink_sysfs(csdev); + case CS_MODE_PERF: + return tmc_enable_etr_sink_perf(csdev, data); + } + + /* We shouldn't be here */ + return -EINVAL; +} + +static int 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 -EBUSY; + } + + if (atomic_dec_return(csdev->refcnt)) { + spin_unlock_irqrestore(&drvdata->spinlock, flags); + return -EBUSY; + } + + /* Complain if we (somehow) got out of sync */ + WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED); + tmc_etr_disable_hw(drvdata); + /* Dissociate from monitored process. */ + drvdata->pid = -1; + drvdata->mode = CS_MODE_DISABLED; + /* Reset perf specific data */ + drvdata->perf_buf = NULL; + + spin_unlock_irqrestore(&drvdata->spinlock, flags); + + dev_dbg(&csdev->dev, "TMC-ETR disabled\n"); + return 0; +} + +static const struct coresight_ops_sink tmc_etr_sink_ops = { + .enable = tmc_enable_etr_sink, + .disable = tmc_disable_etr_sink, + .alloc_buffer = tmc_alloc_etr_buffer, + .update_buffer = tmc_update_etr_buffer, + .free_buffer = tmc_free_etr_buffer, +}; + +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; + } + + /* + * We can safely allow reads even if the ETR is operating in PERF mode, + * since the sysfs session is captured in mode specific data. + * If drvdata::sysfs_data 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); + } 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; +} |