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

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
tmc_etr_sg_table_entries
tmc_pages_get_offset
tmc_pages_free
tmc_pages_alloc
tmc_sg_get_data_page_offset
tmc_free_table_pages
tmc_free_data_pages
tmc_free_sg_table
tmc_alloc_table_pages
tmc_alloc_data_pages
tmc_alloc_sg_table
tmc_sg_table_sync_data_range
tmc_sg_table_sync_table
tmc_sg_table_get_data
tmc_sg_daddr_to_vaddr
tmc_etr_sg_table_dump
tmc_etr_sg_table_dump
tmc_etr_sg_table_populate
tmc_init_etr_sg_table
tmc_etr_alloc_flat_buf
tmc_etr_free_flat_buf
tmc_etr_sync_flat_buf
tmc_etr_get_data_flat_buf
tmc_etr_alloc_sg_buf
tmc_etr_free_sg_buf
tmc_etr_get_data_sg_buf
tmc_etr_sync_sg_buf
tmc_etr_get_catu_device
tmc_etr_enable_catu
tmc_etr_disable_catu
tmc_etr_mode_alloc_buf
tmc_alloc_etr_buf
tmc_free_etr_buf
tmc_etr_buf_get_data
tmc_etr_buf_insert_barrier_packet
tmc_sync_etr_buf
__tmc_etr_enable_hw
tmc_etr_enable_hw
tmc_etr_get_sysfs_trace
tmc_etr_setup_sysfs_buf
tmc_etr_free_sysfs_buf
tmc_etr_sync_sysfs_buf
__tmc_etr_disable_hw
tmc_etr_disable_hw
tmc_enable_etr_sink_sysfs
alloc_etr_buf
get_perf_etr_buf_cpu_wide
get_perf_etr_buf_per_thread
get_perf_etr_buf
tmc_etr_setup_perf_buf
tmc_alloc_etr_buffer
tmc_free_etr_buffer
tmc_etr_sync_perf_buffer
tmc_update_etr_buffer
tmc_enable_etr_sink_perf
tmc_enable_etr_sink
tmc_disable_etr_sink
tmc_read_prepare_etr
tmc_read_unprepare_etr
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright(C) 2016 Linaro Limited. All rights reserved.
   4  * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
   5  */
   6 
   7 #include <linux/atomic.h>
   8 #include <linux/coresight.h>
   9 #include <linux/dma-mapping.h>
  10 #include <linux/iommu.h>
  11 #include <linux/idr.h>
  12 #include <linux/mutex.h>
  13 #include <linux/refcount.h>
  14 #include <linux/slab.h>
  15 #include <linux/types.h>
  16 #include <linux/vmalloc.h>
  17 #include "coresight-catu.h"
  18 #include "coresight-etm-perf.h"
  19 #include "coresight-priv.h"
  20 #include "coresight-tmc.h"
  21 
  22 struct etr_flat_buf {
  23         struct device   *dev;
  24         dma_addr_t      daddr;
  25         void            *vaddr;
  26         size_t          size;
  27 };
  28 
  29 /*
  30  * etr_perf_buffer - Perf buffer used for ETR
  31  * @drvdata             - The ETR drvdaga this buffer has been allocated for.
  32  * @etr_buf             - Actual buffer used by the ETR
  33  * @pid                 - The PID this etr_perf_buffer belongs to.
  34  * @snaphost            - Perf session mode
  35  * @head                - handle->head at the beginning of the session.
  36  * @nr_pages            - Number of pages in the ring buffer.
  37  * @pages               - Array of Pages in the ring buffer.
  38  */
  39 struct etr_perf_buffer {
  40         struct tmc_drvdata      *drvdata;
  41         struct etr_buf          *etr_buf;
  42         pid_t                   pid;
  43         bool                    snapshot;
  44         unsigned long           head;
  45         int                     nr_pages;
  46         void                    **pages;
  47 };
  48 
  49 /* Convert the perf index to an offset within the ETR buffer */
  50 #define PERF_IDX2OFF(idx, buf)  ((idx) % ((buf)->nr_pages << PAGE_SHIFT))
  51 
  52 /* Lower limit for ETR hardware buffer */
  53 #define TMC_ETR_PERF_MIN_BUF_SIZE       SZ_1M
  54 
  55 /*
  56  * The TMC ETR SG has a page size of 4K. The SG table contains pointers
  57  * to 4KB buffers. However, the OS may use a PAGE_SIZE different from
  58  * 4K (i.e, 16KB or 64KB). This implies that a single OS page could
  59  * contain more than one SG buffer and tables.
  60  *
  61  * A table entry has the following format:
  62  *
  63  * ---Bit31------------Bit4-------Bit1-----Bit0--
  64  * |     Address[39:12]    | SBZ |  Entry Type  |
  65  * ----------------------------------------------
  66  *
  67  * Address: Bits [39:12] of a physical page address. Bits [11:0] are
  68  *          always zero.
  69  *
  70  * Entry type:
  71  *      b00 - Reserved.
  72  *      b01 - Last entry in the tables, points to 4K page buffer.
  73  *      b10 - Normal entry, points to 4K page buffer.
  74  *      b11 - Link. The address points to the base of next table.
  75  */
  76 
  77 typedef u32 sgte_t;
  78 
  79 #define ETR_SG_PAGE_SHIFT               12
  80 #define ETR_SG_PAGE_SIZE                (1UL << ETR_SG_PAGE_SHIFT)
  81 #define ETR_SG_PAGES_PER_SYSPAGE        (PAGE_SIZE / ETR_SG_PAGE_SIZE)
  82 #define ETR_SG_PTRS_PER_PAGE            (ETR_SG_PAGE_SIZE / sizeof(sgte_t))
  83 #define ETR_SG_PTRS_PER_SYSPAGE         (PAGE_SIZE / sizeof(sgte_t))
  84 
  85 #define ETR_SG_ET_MASK                  0x3
  86 #define ETR_SG_ET_LAST                  0x1
  87 #define ETR_SG_ET_NORMAL                0x2
  88 #define ETR_SG_ET_LINK                  0x3
  89 
  90 #define ETR_SG_ADDR_SHIFT               4
  91 
  92 #define ETR_SG_ENTRY(addr, type) \
  93         (sgte_t)((((addr) >> ETR_SG_PAGE_SHIFT) << ETR_SG_ADDR_SHIFT) | \
  94                  (type & ETR_SG_ET_MASK))
  95 
  96 #define ETR_SG_ADDR(entry) \
  97         (((dma_addr_t)(entry) >> ETR_SG_ADDR_SHIFT) << ETR_SG_PAGE_SHIFT)
  98 #define ETR_SG_ET(entry)                ((entry) & ETR_SG_ET_MASK)
  99 
 100 /*
 101  * struct etr_sg_table : ETR SG Table
 102  * @sg_table:           Generic SG Table holding the data/table pages.
 103  * @hwaddr:             hwaddress used by the TMC, which is the base
 104  *                      address of the table.
 105  */
 106 struct etr_sg_table {
 107         struct tmc_sg_table     *sg_table;
 108         dma_addr_t              hwaddr;
 109 };
 110 
 111 /*
 112  * tmc_etr_sg_table_entries: Total number of table entries required to map
 113  * @nr_pages system pages.
 114  *
 115  * We need to map @nr_pages * ETR_SG_PAGES_PER_SYSPAGE data pages.
 116  * Each TMC page can map (ETR_SG_PTRS_PER_PAGE - 1) buffer pointers,
 117  * with the last entry pointing to another page of table entries.
 118  * If we spill over to a new page for mapping 1 entry, we could as
 119  * well replace the link entry of the previous page with the last entry.
 120  */
 121 static inline unsigned long __attribute_const__
 122 tmc_etr_sg_table_entries(int nr_pages)
 123 {
 124         unsigned long nr_sgpages = nr_pages * ETR_SG_PAGES_PER_SYSPAGE;
 125         unsigned long nr_sglinks = nr_sgpages / (ETR_SG_PTRS_PER_PAGE - 1);
 126         /*
 127          * If we spill over to a new page for 1 entry, we could as well
 128          * make it the LAST entry in the previous page, skipping the Link
 129          * address.
 130          */
 131         if (nr_sglinks && (nr_sgpages % (ETR_SG_PTRS_PER_PAGE - 1) < 2))
 132                 nr_sglinks--;
 133         return nr_sgpages + nr_sglinks;
 134 }
 135 
 136 /*
 137  * tmc_pages_get_offset:  Go through all the pages in the tmc_pages
 138  * and map the device address @addr to an offset within the virtual
 139  * contiguous buffer.
 140  */
 141 static long
 142 tmc_pages_get_offset(struct tmc_pages *tmc_pages, dma_addr_t addr)
 143 {
 144         int i;
 145         dma_addr_t page_start;
 146 
 147         for (i = 0; i < tmc_pages->nr_pages; i++) {
 148                 page_start = tmc_pages->daddrs[i];
 149                 if (addr >= page_start && addr < (page_start + PAGE_SIZE))
 150                         return i * PAGE_SIZE + (addr - page_start);
 151         }
 152 
 153         return -EINVAL;
 154 }
 155 
 156 /*
 157  * tmc_pages_free : Unmap and free the pages used by tmc_pages.
 158  * If the pages were not allocated in tmc_pages_alloc(), we would
 159  * simply drop the refcount.
 160  */
 161 static void tmc_pages_free(struct tmc_pages *tmc_pages,
 162                            struct device *dev, enum dma_data_direction dir)
 163 {
 164         int i;
 165         struct device *real_dev = dev->parent;
 166 
 167         for (i = 0; i < tmc_pages->nr_pages; i++) {
 168                 if (tmc_pages->daddrs && tmc_pages->daddrs[i])
 169                         dma_unmap_page(real_dev, tmc_pages->daddrs[i],
 170                                          PAGE_SIZE, dir);
 171                 if (tmc_pages->pages && tmc_pages->pages[i])
 172                         __free_page(tmc_pages->pages[i]);
 173         }
 174 
 175         kfree(tmc_pages->pages);
 176         kfree(tmc_pages->daddrs);
 177         tmc_pages->pages = NULL;
 178         tmc_pages->daddrs = NULL;
 179         tmc_pages->nr_pages = 0;
 180 }
 181 
 182 /*
 183  * tmc_pages_alloc : Allocate and map pages for a given @tmc_pages.
 184  * If @pages is not NULL, the list of page virtual addresses are
 185  * used as the data pages. The pages are then dma_map'ed for @dev
 186  * with dma_direction @dir.
 187  *
 188  * Returns 0 upon success, else the error number.
 189  */
 190 static int tmc_pages_alloc(struct tmc_pages *tmc_pages,
 191                            struct device *dev, int node,
 192                            enum dma_data_direction dir, void **pages)
 193 {
 194         int i, nr_pages;
 195         dma_addr_t paddr;
 196         struct page *page;
 197         struct device *real_dev = dev->parent;
 198 
 199         nr_pages = tmc_pages->nr_pages;
 200         tmc_pages->daddrs = kcalloc(nr_pages, sizeof(*tmc_pages->daddrs),
 201                                          GFP_KERNEL);
 202         if (!tmc_pages->daddrs)
 203                 return -ENOMEM;
 204         tmc_pages->pages = kcalloc(nr_pages, sizeof(*tmc_pages->pages),
 205                                          GFP_KERNEL);
 206         if (!tmc_pages->pages) {
 207                 kfree(tmc_pages->daddrs);
 208                 tmc_pages->daddrs = NULL;
 209                 return -ENOMEM;
 210         }
 211 
 212         for (i = 0; i < nr_pages; i++) {
 213                 if (pages && pages[i]) {
 214                         page = virt_to_page(pages[i]);
 215                         /* Hold a refcount on the page */
 216                         get_page(page);
 217                 } else {
 218                         page = alloc_pages_node(node,
 219                                                 GFP_KERNEL | __GFP_ZERO, 0);
 220                 }
 221                 paddr = dma_map_page(real_dev, page, 0, PAGE_SIZE, dir);
 222                 if (dma_mapping_error(real_dev, paddr))
 223                         goto err;
 224                 tmc_pages->daddrs[i] = paddr;
 225                 tmc_pages->pages[i] = page;
 226         }
 227         return 0;
 228 err:
 229         tmc_pages_free(tmc_pages, dev, dir);
 230         return -ENOMEM;
 231 }
 232 
 233 static inline long
 234 tmc_sg_get_data_page_offset(struct tmc_sg_table *sg_table, dma_addr_t addr)
 235 {
 236         return tmc_pages_get_offset(&sg_table->data_pages, addr);
 237 }
 238 
 239 static inline void tmc_free_table_pages(struct tmc_sg_table *sg_table)
 240 {
 241         if (sg_table->table_vaddr)
 242                 vunmap(sg_table->table_vaddr);
 243         tmc_pages_free(&sg_table->table_pages, sg_table->dev, DMA_TO_DEVICE);
 244 }
 245 
 246 static void tmc_free_data_pages(struct tmc_sg_table *sg_table)
 247 {
 248         if (sg_table->data_vaddr)
 249                 vunmap(sg_table->data_vaddr);
 250         tmc_pages_free(&sg_table->data_pages, sg_table->dev, DMA_FROM_DEVICE);
 251 }
 252 
 253 void tmc_free_sg_table(struct tmc_sg_table *sg_table)
 254 {
 255         tmc_free_table_pages(sg_table);
 256         tmc_free_data_pages(sg_table);
 257 }
 258 
 259 /*
 260  * Alloc pages for the table. Since this will be used by the device,
 261  * allocate the pages closer to the device (i.e, dev_to_node(dev)
 262  * rather than the CPU node).
 263  */
 264 static int tmc_alloc_table_pages(struct tmc_sg_table *sg_table)
 265 {
 266         int rc;
 267         struct tmc_pages *table_pages = &sg_table->table_pages;
 268 
 269         rc = tmc_pages_alloc(table_pages, sg_table->dev,
 270                              dev_to_node(sg_table->dev),
 271                              DMA_TO_DEVICE, NULL);
 272         if (rc)
 273                 return rc;
 274         sg_table->table_vaddr = vmap(table_pages->pages,
 275                                      table_pages->nr_pages,
 276                                      VM_MAP,
 277                                      PAGE_KERNEL);
 278         if (!sg_table->table_vaddr)
 279                 rc = -ENOMEM;
 280         else
 281                 sg_table->table_daddr = table_pages->daddrs[0];
 282         return rc;
 283 }
 284 
 285 static int tmc_alloc_data_pages(struct tmc_sg_table *sg_table, void **pages)
 286 {
 287         int rc;
 288 
 289         /* Allocate data pages on the node requested by the caller */
 290         rc = tmc_pages_alloc(&sg_table->data_pages,
 291                              sg_table->dev, sg_table->node,
 292                              DMA_FROM_DEVICE, pages);
 293         if (!rc) {
 294                 sg_table->data_vaddr = vmap(sg_table->data_pages.pages,
 295                                             sg_table->data_pages.nr_pages,
 296                                             VM_MAP,
 297                                             PAGE_KERNEL);
 298                 if (!sg_table->data_vaddr)
 299                         rc = -ENOMEM;
 300         }
 301         return rc;
 302 }
 303 
 304 /*
 305  * tmc_alloc_sg_table: Allocate and setup dma pages for the TMC SG table
 306  * and data buffers. TMC writes to the data buffers and reads from the SG
 307  * Table pages.
 308  *
 309  * @dev         - Coresight device to which page should be DMA mapped.
 310  * @node        - Numa node for mem allocations
 311  * @nr_tpages   - Number of pages for the table entries.
 312  * @nr_dpages   - Number of pages for Data buffer.
 313  * @pages       - Optional list of virtual address of pages.
 314  */
 315 struct tmc_sg_table *tmc_alloc_sg_table(struct device *dev,
 316                                         int node,
 317                                         int nr_tpages,
 318                                         int nr_dpages,
 319                                         void **pages)
 320 {
 321         long rc;
 322         struct tmc_sg_table *sg_table;
 323 
 324         sg_table = kzalloc(sizeof(*sg_table), GFP_KERNEL);
 325         if (!sg_table)
 326                 return ERR_PTR(-ENOMEM);
 327         sg_table->data_pages.nr_pages = nr_dpages;
 328         sg_table->table_pages.nr_pages = nr_tpages;
 329         sg_table->node = node;
 330         sg_table->dev = dev;
 331 
 332         rc  = tmc_alloc_data_pages(sg_table, pages);
 333         if (!rc)
 334                 rc = tmc_alloc_table_pages(sg_table);
 335         if (rc) {
 336                 tmc_free_sg_table(sg_table);
 337                 kfree(sg_table);
 338                 return ERR_PTR(rc);
 339         }
 340 
 341         return sg_table;
 342 }
 343 
 344 /*
 345  * tmc_sg_table_sync_data_range: Sync the data buffer written
 346  * by the device from @offset upto a @size bytes.
 347  */
 348 void tmc_sg_table_sync_data_range(struct tmc_sg_table *table,
 349                                   u64 offset, u64 size)
 350 {
 351         int i, index, start;
 352         int npages = DIV_ROUND_UP(size, PAGE_SIZE);
 353         struct device *real_dev = table->dev->parent;
 354         struct tmc_pages *data = &table->data_pages;
 355 
 356         start = offset >> PAGE_SHIFT;
 357         for (i = start; i < (start + npages); i++) {
 358                 index = i % data->nr_pages;
 359                 dma_sync_single_for_cpu(real_dev, data->daddrs[index],
 360                                         PAGE_SIZE, DMA_FROM_DEVICE);
 361         }
 362 }
 363 
 364 /* tmc_sg_sync_table: Sync the page table */
 365 void tmc_sg_table_sync_table(struct tmc_sg_table *sg_table)
 366 {
 367         int i;
 368         struct device *real_dev = sg_table->dev->parent;
 369         struct tmc_pages *table_pages = &sg_table->table_pages;
 370 
 371         for (i = 0; i < table_pages->nr_pages; i++)
 372                 dma_sync_single_for_device(real_dev, table_pages->daddrs[i],
 373                                            PAGE_SIZE, DMA_TO_DEVICE);
 374 }
 375 
 376 /*
 377  * tmc_sg_table_get_data: Get the buffer pointer for data @offset
 378  * in the SG buffer. The @bufpp is updated to point to the buffer.
 379  * Returns :
 380  *      the length of linear data available at @offset.
 381  *      or
 382  *      <= 0 if no data is available.
 383  */
 384 ssize_t tmc_sg_table_get_data(struct tmc_sg_table *sg_table,
 385                               u64 offset, size_t len, char **bufpp)
 386 {
 387         size_t size;
 388         int pg_idx = offset >> PAGE_SHIFT;
 389         int pg_offset = offset & (PAGE_SIZE - 1);
 390         struct tmc_pages *data_pages = &sg_table->data_pages;
 391 
 392         size = tmc_sg_table_buf_size(sg_table);
 393         if (offset >= size)
 394                 return -EINVAL;
 395 
 396         /* Make sure we don't go beyond the end */
 397         len = (len < (size - offset)) ? len : size - offset;
 398         /* Respect the page boundaries */
 399         len = (len < (PAGE_SIZE - pg_offset)) ? len : (PAGE_SIZE - pg_offset);
 400         if (len > 0)
 401                 *bufpp = page_address(data_pages->pages[pg_idx]) + pg_offset;
 402         return len;
 403 }
 404 
 405 #ifdef ETR_SG_DEBUG
 406 /* Map a dma address to virtual address */
 407 static unsigned long
 408 tmc_sg_daddr_to_vaddr(struct tmc_sg_table *sg_table,
 409                       dma_addr_t addr, bool table)
 410 {
 411         long offset;
 412         unsigned long base;
 413         struct tmc_pages *tmc_pages;
 414 
 415         if (table) {
 416                 tmc_pages = &sg_table->table_pages;
 417                 base = (unsigned long)sg_table->table_vaddr;
 418         } else {
 419                 tmc_pages = &sg_table->data_pages;
 420                 base = (unsigned long)sg_table->data_vaddr;
 421         }
 422 
 423         offset = tmc_pages_get_offset(tmc_pages, addr);
 424         if (offset < 0)
 425                 return 0;
 426         return base + offset;
 427 }
 428 
 429 /* Dump the given sg_table */
 430 static void tmc_etr_sg_table_dump(struct etr_sg_table *etr_table)
 431 {
 432         sgte_t *ptr;
 433         int i = 0;
 434         dma_addr_t addr;
 435         struct tmc_sg_table *sg_table = etr_table->sg_table;
 436 
 437         ptr = (sgte_t *)tmc_sg_daddr_to_vaddr(sg_table,
 438                                               etr_table->hwaddr, true);
 439         while (ptr) {
 440                 addr = ETR_SG_ADDR(*ptr);
 441                 switch (ETR_SG_ET(*ptr)) {
 442                 case ETR_SG_ET_NORMAL:
 443                         dev_dbg(sg_table->dev,
 444                                 "%05d: %p\t:[N] 0x%llx\n", i, ptr, addr);
 445                         ptr++;
 446                         break;
 447                 case ETR_SG_ET_LINK:
 448                         dev_dbg(sg_table->dev,
 449                                 "%05d: *** %p\t:{L} 0x%llx ***\n",
 450                                  i, ptr, addr);
 451                         ptr = (sgte_t *)tmc_sg_daddr_to_vaddr(sg_table,
 452                                                               addr, true);
 453                         break;
 454                 case ETR_SG_ET_LAST:
 455                         dev_dbg(sg_table->dev,
 456                                 "%05d: ### %p\t:[L] 0x%llx ###\n",
 457                                  i, ptr, addr);
 458                         return;
 459                 default:
 460                         dev_dbg(sg_table->dev,
 461                                 "%05d: xxx %p\t:[INVALID] 0x%llx xxx\n",
 462                                  i, ptr, addr);
 463                         return;
 464                 }
 465                 i++;
 466         }
 467         dev_dbg(sg_table->dev, "******* End of Table *****\n");
 468 }
 469 #else
 470 static inline void tmc_etr_sg_table_dump(struct etr_sg_table *etr_table) {}
 471 #endif
 472 
 473 /*
 474  * Populate the SG Table page table entries from table/data
 475  * pages allocated. Each Data page has ETR_SG_PAGES_PER_SYSPAGE SG pages.
 476  * So does a Table page. So we keep track of indices of the tables
 477  * in each system page and move the pointers accordingly.
 478  */
 479 #define INC_IDX_ROUND(idx, size) ((idx) = ((idx) + 1) % (size))
 480 static void tmc_etr_sg_table_populate(struct etr_sg_table *etr_table)
 481 {
 482         dma_addr_t paddr;
 483         int i, type, nr_entries;
 484         int tpidx = 0; /* index to the current system table_page */
 485         int sgtidx = 0; /* index to the sg_table within the current syspage */
 486         int sgtentry = 0; /* the entry within the sg_table */
 487         int dpidx = 0; /* index to the current system data_page */
 488         int spidx = 0; /* index to the SG page within the current data page */
 489         sgte_t *ptr; /* pointer to the table entry to fill */
 490         struct tmc_sg_table *sg_table = etr_table->sg_table;
 491         dma_addr_t *table_daddrs = sg_table->table_pages.daddrs;
 492         dma_addr_t *data_daddrs = sg_table->data_pages.daddrs;
 493 
 494         nr_entries = tmc_etr_sg_table_entries(sg_table->data_pages.nr_pages);
 495         /*
 496          * Use the contiguous virtual address of the table to update entries.
 497          */
 498         ptr = sg_table->table_vaddr;
 499         /*
 500          * Fill all the entries, except the last entry to avoid special
 501          * checks within the loop.
 502          */
 503         for (i = 0; i < nr_entries - 1; i++) {
 504                 if (sgtentry == ETR_SG_PTRS_PER_PAGE - 1) {
 505                         /*
 506                          * Last entry in a sg_table page is a link address to
 507                          * the next table page. If this sg_table is the last
 508                          * one in the system page, it links to the first
 509                          * sg_table in the next system page. Otherwise, it
 510                          * links to the next sg_table page within the system
 511                          * page.
 512                          */
 513                         if (sgtidx == ETR_SG_PAGES_PER_SYSPAGE - 1) {
 514                                 paddr = table_daddrs[tpidx + 1];
 515                         } else {
 516                                 paddr = table_daddrs[tpidx] +
 517                                         (ETR_SG_PAGE_SIZE * (sgtidx + 1));
 518                         }
 519                         type = ETR_SG_ET_LINK;
 520                 } else {
 521                         /*
 522                          * Update the indices to the data_pages to point to the
 523                          * next sg_page in the data buffer.
 524                          */
 525                         type = ETR_SG_ET_NORMAL;
 526                         paddr = data_daddrs[dpidx] + spidx * ETR_SG_PAGE_SIZE;
 527                         if (!INC_IDX_ROUND(spidx, ETR_SG_PAGES_PER_SYSPAGE))
 528                                 dpidx++;
 529                 }
 530                 *ptr++ = ETR_SG_ENTRY(paddr, type);
 531                 /*
 532                  * Move to the next table pointer, moving the table page index
 533                  * if necessary
 534                  */
 535                 if (!INC_IDX_ROUND(sgtentry, ETR_SG_PTRS_PER_PAGE)) {
 536                         if (!INC_IDX_ROUND(sgtidx, ETR_SG_PAGES_PER_SYSPAGE))
 537                                 tpidx++;
 538                 }
 539         }
 540 
 541         /* Set up the last entry, which is always a data pointer */
 542         paddr = data_daddrs[dpidx] + spidx * ETR_SG_PAGE_SIZE;
 543         *ptr++ = ETR_SG_ENTRY(paddr, ETR_SG_ET_LAST);
 544 }
 545 
 546 /*
 547  * tmc_init_etr_sg_table: Allocate a TMC ETR SG table, data buffer of @size and
 548  * populate the table.
 549  *
 550  * @dev         - Device pointer for the TMC
 551  * @node        - NUMA node where the memory should be allocated
 552  * @size        - Total size of the data buffer
 553  * @pages       - Optional list of page virtual address
 554  */
 555 static struct etr_sg_table *
 556 tmc_init_etr_sg_table(struct device *dev, int node,
 557                       unsigned long size, void **pages)
 558 {
 559         int nr_entries, nr_tpages;
 560         int nr_dpages = size >> PAGE_SHIFT;
 561         struct tmc_sg_table *sg_table;
 562         struct etr_sg_table *etr_table;
 563 
 564         etr_table = kzalloc(sizeof(*etr_table), GFP_KERNEL);
 565         if (!etr_table)
 566                 return ERR_PTR(-ENOMEM);
 567         nr_entries = tmc_etr_sg_table_entries(nr_dpages);
 568         nr_tpages = DIV_ROUND_UP(nr_entries, ETR_SG_PTRS_PER_SYSPAGE);
 569 
 570         sg_table = tmc_alloc_sg_table(dev, node, nr_tpages, nr_dpages, pages);
 571         if (IS_ERR(sg_table)) {
 572                 kfree(etr_table);
 573                 return ERR_CAST(sg_table);
 574         }
 575 
 576         etr_table->sg_table = sg_table;
 577         /* TMC should use table base address for DBA */
 578         etr_table->hwaddr = sg_table->table_daddr;
 579         tmc_etr_sg_table_populate(etr_table);
 580         /* Sync the table pages for the HW */
 581         tmc_sg_table_sync_table(sg_table);
 582         tmc_etr_sg_table_dump(etr_table);
 583 
 584         return etr_table;
 585 }
 586 
 587 /*
 588  * tmc_etr_alloc_flat_buf: Allocate a contiguous DMA buffer.
 589  */
 590 static int tmc_etr_alloc_flat_buf(struct tmc_drvdata *drvdata,
 591                                   struct etr_buf *etr_buf, int node,
 592                                   void **pages)
 593 {
 594         struct etr_flat_buf *flat_buf;
 595         struct device *real_dev = drvdata->csdev->dev.parent;
 596 
 597         /* We cannot reuse existing pages for flat buf */
 598         if (pages)
 599                 return -EINVAL;
 600 
 601         flat_buf = kzalloc(sizeof(*flat_buf), GFP_KERNEL);
 602         if (!flat_buf)
 603                 return -ENOMEM;
 604 
 605         flat_buf->vaddr = dma_alloc_coherent(real_dev, etr_buf->size,
 606                                              &flat_buf->daddr, GFP_KERNEL);
 607         if (!flat_buf->vaddr) {
 608                 kfree(flat_buf);
 609                 return -ENOMEM;
 610         }
 611 
 612         flat_buf->size = etr_buf->size;
 613         flat_buf->dev = &drvdata->csdev->dev;
 614         etr_buf->hwaddr = flat_buf->daddr;
 615         etr_buf->mode = ETR_MODE_FLAT;
 616         etr_buf->private = flat_buf;
 617         return 0;
 618 }
 619 
 620 static void tmc_etr_free_flat_buf(struct etr_buf *etr_buf)
 621 {
 622         struct etr_flat_buf *flat_buf = etr_buf->private;
 623 
 624         if (flat_buf && flat_buf->daddr) {
 625                 struct device *real_dev = flat_buf->dev->parent;
 626 
 627                 dma_free_coherent(real_dev, flat_buf->size,
 628                                   flat_buf->vaddr, flat_buf->daddr);
 629         }
 630         kfree(flat_buf);
 631 }
 632 
 633 static void tmc_etr_sync_flat_buf(struct etr_buf *etr_buf, u64 rrp, u64 rwp)
 634 {
 635         /*
 636          * Adjust the buffer to point to the beginning of the trace data
 637          * and update the available trace data.
 638          */
 639         etr_buf->offset = rrp - etr_buf->hwaddr;
 640         if (etr_buf->full)
 641                 etr_buf->len = etr_buf->size;
 642         else
 643                 etr_buf->len = rwp - rrp;
 644 }
 645 
 646 static ssize_t tmc_etr_get_data_flat_buf(struct etr_buf *etr_buf,
 647                                          u64 offset, size_t len, char **bufpp)
 648 {
 649         struct etr_flat_buf *flat_buf = etr_buf->private;
 650 
 651         *bufpp = (char *)flat_buf->vaddr + offset;
 652         /*
 653          * tmc_etr_buf_get_data already adjusts the length to handle
 654          * buffer wrapping around.
 655          */
 656         return len;
 657 }
 658 
 659 static const struct etr_buf_operations etr_flat_buf_ops = {
 660         .alloc = tmc_etr_alloc_flat_buf,
 661         .free = tmc_etr_free_flat_buf,
 662         .sync = tmc_etr_sync_flat_buf,
 663         .get_data = tmc_etr_get_data_flat_buf,
 664 };
 665 
 666 /*
 667  * tmc_etr_alloc_sg_buf: Allocate an SG buf @etr_buf. Setup the parameters
 668  * appropriately.
 669  */
 670 static int tmc_etr_alloc_sg_buf(struct tmc_drvdata *drvdata,
 671                                 struct etr_buf *etr_buf, int node,
 672                                 void **pages)
 673 {
 674         struct etr_sg_table *etr_table;
 675         struct device *dev = &drvdata->csdev->dev;
 676 
 677         etr_table = tmc_init_etr_sg_table(dev, node,
 678                                           etr_buf->size, pages);
 679         if (IS_ERR(etr_table))
 680                 return -ENOMEM;
 681         etr_buf->hwaddr = etr_table->hwaddr;
 682         etr_buf->mode = ETR_MODE_ETR_SG;
 683         etr_buf->private = etr_table;
 684         return 0;
 685 }
 686 
 687 static void tmc_etr_free_sg_buf(struct etr_buf *etr_buf)
 688 {
 689         struct etr_sg_table *etr_table = etr_buf->private;
 690 
 691         if (etr_table) {
 692                 tmc_free_sg_table(etr_table->sg_table);
 693                 kfree(etr_table);
 694         }
 695 }
 696 
 697 static ssize_t tmc_etr_get_data_sg_buf(struct etr_buf *etr_buf, u64 offset,
 698                                        size_t len, char **bufpp)
 699 {
 700         struct etr_sg_table *etr_table = etr_buf->private;
 701 
 702         return tmc_sg_table_get_data(etr_table->sg_table, offset, len, bufpp);
 703 }
 704 
 705 static void tmc_etr_sync_sg_buf(struct etr_buf *etr_buf, u64 rrp, u64 rwp)
 706 {
 707         long r_offset, w_offset;
 708         struct etr_sg_table *etr_table = etr_buf->private;
 709         struct tmc_sg_table *table = etr_table->sg_table;
 710 
 711         /* Convert hw address to offset in the buffer */
 712         r_offset = tmc_sg_get_data_page_offset(table, rrp);
 713         if (r_offset < 0) {
 714                 dev_warn(table->dev,
 715                          "Unable to map RRP %llx to offset\n", rrp);
 716                 etr_buf->len = 0;
 717                 return;
 718         }
 719 
 720         w_offset = tmc_sg_get_data_page_offset(table, rwp);
 721         if (w_offset < 0) {
 722                 dev_warn(table->dev,
 723                          "Unable to map RWP %llx to offset\n", rwp);
 724                 etr_buf->len = 0;
 725                 return;
 726         }
 727 
 728         etr_buf->offset = r_offset;
 729         if (etr_buf->full)
 730                 etr_buf->len = etr_buf->size;
 731         else
 732                 etr_buf->len = ((w_offset < r_offset) ? etr_buf->size : 0) +
 733                                 w_offset - r_offset;
 734         tmc_sg_table_sync_data_range(table, r_offset, etr_buf->len);
 735 }
 736 
 737 static const struct etr_buf_operations etr_sg_buf_ops = {
 738         .alloc = tmc_etr_alloc_sg_buf,
 739         .free = tmc_etr_free_sg_buf,
 740         .sync = tmc_etr_sync_sg_buf,
 741         .get_data = tmc_etr_get_data_sg_buf,
 742 };
 743 
 744 /*
 745  * TMC ETR could be connected to a CATU device, which can provide address
 746  * translation service. This is represented by the Output port of the TMC
 747  * (ETR) connected to the input port of the CATU.
 748  *
 749  * Returns      : coresight_device ptr for the CATU device if a CATU is found.
 750  *              : NULL otherwise.
 751  */
 752 struct coresight_device *
 753 tmc_etr_get_catu_device(struct tmc_drvdata *drvdata)
 754 {
 755         int i;
 756         struct coresight_device *tmp, *etr = drvdata->csdev;
 757 
 758         if (!IS_ENABLED(CONFIG_CORESIGHT_CATU))
 759                 return NULL;
 760 
 761         for (i = 0; i < etr->pdata->nr_outport; i++) {
 762                 tmp = etr->pdata->conns[i].child_dev;
 763                 if (tmp && coresight_is_catu_device(tmp))
 764                         return tmp;
 765         }
 766 
 767         return NULL;
 768 }
 769 
 770 static inline int tmc_etr_enable_catu(struct tmc_drvdata *drvdata,
 771                                       struct etr_buf *etr_buf)
 772 {
 773         struct coresight_device *catu = tmc_etr_get_catu_device(drvdata);
 774 
 775         if (catu && helper_ops(catu)->enable)
 776                 return helper_ops(catu)->enable(catu, etr_buf);
 777         return 0;
 778 }
 779 
 780 static inline void tmc_etr_disable_catu(struct tmc_drvdata *drvdata)
 781 {
 782         struct coresight_device *catu = tmc_etr_get_catu_device(drvdata);
 783 
 784         if (catu && helper_ops(catu)->disable)
 785                 helper_ops(catu)->disable(catu, drvdata->etr_buf);
 786 }
 787 
 788 static const struct etr_buf_operations *etr_buf_ops[] = {
 789         [ETR_MODE_FLAT] = &etr_flat_buf_ops,
 790         [ETR_MODE_ETR_SG] = &etr_sg_buf_ops,
 791         [ETR_MODE_CATU] = IS_ENABLED(CONFIG_CORESIGHT_CATU)
 792                                                 ? &etr_catu_buf_ops : NULL,
 793 };
 794 
 795 static inline int tmc_etr_mode_alloc_buf(int mode,
 796                                          struct tmc_drvdata *drvdata,
 797                                          struct etr_buf *etr_buf, int node,
 798                                          void **pages)
 799 {
 800         int rc = -EINVAL;
 801 
 802         switch (mode) {
 803         case ETR_MODE_FLAT:
 804         case ETR_MODE_ETR_SG:
 805         case ETR_MODE_CATU:
 806                 if (etr_buf_ops[mode] && etr_buf_ops[mode]->alloc)
 807                         rc = etr_buf_ops[mode]->alloc(drvdata, etr_buf,
 808                                                       node, pages);
 809                 if (!rc)
 810                         etr_buf->ops = etr_buf_ops[mode];
 811                 return rc;
 812         default:
 813                 return -EINVAL;
 814         }
 815 }
 816 
 817 /*
 818  * tmc_alloc_etr_buf: Allocate a buffer use by ETR.
 819  * @drvdata     : ETR device details.
 820  * @size        : size of the requested buffer.
 821  * @flags       : Required properties for the buffer.
 822  * @node        : Node for memory allocations.
 823  * @pages       : An optional list of pages.
 824  */
 825 static struct etr_buf *tmc_alloc_etr_buf(struct tmc_drvdata *drvdata,
 826                                          ssize_t size, int flags,
 827                                          int node, void **pages)
 828 {
 829         int rc = -ENOMEM;
 830         bool has_etr_sg, has_iommu;
 831         bool has_sg, has_catu;
 832         struct etr_buf *etr_buf;
 833         struct device *dev = &drvdata->csdev->dev;
 834 
 835         has_etr_sg = tmc_etr_has_cap(drvdata, TMC_ETR_SG);
 836         has_iommu = iommu_get_domain_for_dev(dev->parent);
 837         has_catu = !!tmc_etr_get_catu_device(drvdata);
 838 
 839         has_sg = has_catu || has_etr_sg;
 840 
 841         etr_buf = kzalloc(sizeof(*etr_buf), GFP_KERNEL);
 842         if (!etr_buf)
 843                 return ERR_PTR(-ENOMEM);
 844 
 845         etr_buf->size = size;
 846 
 847         /*
 848          * If we have to use an existing list of pages, we cannot reliably
 849          * use a contiguous DMA memory (even if we have an IOMMU). Otherwise,
 850          * we use the contiguous DMA memory if at least one of the following
 851          * conditions is true:
 852          *  a) The ETR cannot use Scatter-Gather.
 853          *  b) we have a backing IOMMU
 854          *  c) The requested memory size is smaller (< 1M).
 855          *
 856          * Fallback to available mechanisms.
 857          *
 858          */
 859         if (!pages &&
 860             (!has_sg || has_iommu || size < SZ_1M))
 861                 rc = tmc_etr_mode_alloc_buf(ETR_MODE_FLAT, drvdata,
 862                                             etr_buf, node, pages);
 863         if (rc && has_etr_sg)
 864                 rc = tmc_etr_mode_alloc_buf(ETR_MODE_ETR_SG, drvdata,
 865                                             etr_buf, node, pages);
 866         if (rc && has_catu)
 867                 rc = tmc_etr_mode_alloc_buf(ETR_MODE_CATU, drvdata,
 868                                             etr_buf, node, pages);
 869         if (rc) {
 870                 kfree(etr_buf);
 871                 return ERR_PTR(rc);
 872         }
 873 
 874         refcount_set(&etr_buf->refcount, 1);
 875         dev_dbg(dev, "allocated buffer of size %ldKB in mode %d\n",
 876                 (unsigned long)size >> 10, etr_buf->mode);
 877         return etr_buf;
 878 }
 879 
 880 static void tmc_free_etr_buf(struct etr_buf *etr_buf)
 881 {
 882         WARN_ON(!etr_buf->ops || !etr_buf->ops->free);
 883         etr_buf->ops->free(etr_buf);
 884         kfree(etr_buf);
 885 }
 886 
 887 /*
 888  * tmc_etr_buf_get_data: Get the pointer the trace data at @offset
 889  * with a maximum of @len bytes.
 890  * Returns: The size of the linear data available @pos, with *bufpp
 891  * updated to point to the buffer.
 892  */
 893 static ssize_t tmc_etr_buf_get_data(struct etr_buf *etr_buf,
 894                                     u64 offset, size_t len, char **bufpp)
 895 {
 896         /* Adjust the length to limit this transaction to end of buffer */
 897         len = (len < (etr_buf->size - offset)) ? len : etr_buf->size - offset;
 898 
 899         return etr_buf->ops->get_data(etr_buf, (u64)offset, len, bufpp);
 900 }
 901 
 902 static inline s64
 903 tmc_etr_buf_insert_barrier_packet(struct etr_buf *etr_buf, u64 offset)
 904 {
 905         ssize_t len;
 906         char *bufp;
 907 
 908         len = tmc_etr_buf_get_data(etr_buf, offset,
 909                                    CORESIGHT_BARRIER_PKT_SIZE, &bufp);
 910         if (WARN_ON(len < CORESIGHT_BARRIER_PKT_SIZE))
 911                 return -EINVAL;
 912         coresight_insert_barrier_packet(bufp);
 913         return offset + CORESIGHT_BARRIER_PKT_SIZE;
 914 }
 915 
 916 /*
 917  * tmc_sync_etr_buf: Sync the trace buffer availability with drvdata.
 918  * Makes sure the trace data is synced to the memory for consumption.
 919  * @etr_buf->offset will hold the offset to the beginning of the trace data
 920  * within the buffer, with @etr_buf->len bytes to consume.
 921  */
 922 static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata)
 923 {
 924         struct etr_buf *etr_buf = drvdata->etr_buf;
 925         u64 rrp, rwp;
 926         u32 status;
 927 
 928         rrp = tmc_read_rrp(drvdata);
 929         rwp = tmc_read_rwp(drvdata);
 930         status = readl_relaxed(drvdata->base + TMC_STS);
 931 
 932         /*
 933          * If there were memory errors in the session, truncate the
 934          * buffer.
 935          */
 936         if (WARN_ON_ONCE(status & TMC_STS_MEMERR)) {
 937                 dev_dbg(&drvdata->csdev->dev,
 938                         "tmc memory error detected, truncating buffer\n");
 939                 etr_buf->len = 0;
 940                 etr_buf->full = 0;
 941                 return;
 942         }
 943 
 944         etr_buf->full = status & TMC_STS_FULL;
 945 
 946         WARN_ON(!etr_buf->ops || !etr_buf->ops->sync);
 947 
 948         etr_buf->ops->sync(etr_buf, rrp, rwp);
 949 }
 950 
 951 static void __tmc_etr_enable_hw(struct tmc_drvdata *drvdata)
 952 {
 953         u32 axictl, sts;
 954         struct etr_buf *etr_buf = drvdata->etr_buf;
 955 
 956         CS_UNLOCK(drvdata->base);
 957 
 958         /* Wait for TMCSReady bit to be set */
 959         tmc_wait_for_tmcready(drvdata);
 960 
 961         writel_relaxed(etr_buf->size / 4, drvdata->base + TMC_RSZ);
 962         writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE);
 963 
 964         axictl = readl_relaxed(drvdata->base + TMC_AXICTL);
 965         axictl &= ~TMC_AXICTL_CLEAR_MASK;
 966         axictl |= (TMC_AXICTL_PROT_CTL_B1 | TMC_AXICTL_WR_BURST_16);
 967         axictl |= TMC_AXICTL_AXCACHE_OS;
 968 
 969         if (tmc_etr_has_cap(drvdata, TMC_ETR_AXI_ARCACHE)) {
 970                 axictl &= ~TMC_AXICTL_ARCACHE_MASK;
 971                 axictl |= TMC_AXICTL_ARCACHE_OS;
 972         }
 973 
 974         if (etr_buf->mode == ETR_MODE_ETR_SG)
 975                 axictl |= TMC_AXICTL_SCT_GAT_MODE;
 976 
 977         writel_relaxed(axictl, drvdata->base + TMC_AXICTL);
 978         tmc_write_dba(drvdata, etr_buf->hwaddr);
 979         /*
 980          * If the TMC pointers must be programmed before the session,
 981          * we have to set it properly (i.e, RRP/RWP to base address and
 982          * STS to "not full").
 983          */
 984         if (tmc_etr_has_cap(drvdata, TMC_ETR_SAVE_RESTORE)) {
 985                 tmc_write_rrp(drvdata, etr_buf->hwaddr);
 986                 tmc_write_rwp(drvdata, etr_buf->hwaddr);
 987                 sts = readl_relaxed(drvdata->base + TMC_STS) & ~TMC_STS_FULL;
 988                 writel_relaxed(sts, drvdata->base + TMC_STS);
 989         }
 990 
 991         writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI |
 992                        TMC_FFCR_FON_FLIN | TMC_FFCR_FON_TRIG_EVT |
 993                        TMC_FFCR_TRIGON_TRIGIN,
 994                        drvdata->base + TMC_FFCR);
 995         writel_relaxed(drvdata->trigger_cntr, drvdata->base + TMC_TRG);
 996         tmc_enable_hw(drvdata);
 997 
 998         CS_LOCK(drvdata->base);
 999 }
1000 
1001 static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata,
1002                              struct etr_buf *etr_buf)
1003 {
1004         int rc;
1005 
1006         /* Callers should provide an appropriate buffer for use */
1007         if (WARN_ON(!etr_buf))
1008                 return -EINVAL;
1009 
1010         if ((etr_buf->mode == ETR_MODE_ETR_SG) &&
1011             WARN_ON(!tmc_etr_has_cap(drvdata, TMC_ETR_SG)))
1012                 return -EINVAL;
1013 
1014         if (WARN_ON(drvdata->etr_buf))
1015                 return -EBUSY;
1016 
1017         /*
1018          * If this ETR is connected to a CATU, enable it before we turn
1019          * this on.
1020          */
1021         rc = tmc_etr_enable_catu(drvdata, etr_buf);
1022         if (rc)
1023                 return rc;
1024         rc = coresight_claim_device(drvdata->base);
1025         if (!rc) {
1026                 drvdata->etr_buf = etr_buf;
1027                 __tmc_etr_enable_hw(drvdata);
1028         }
1029 
1030         return rc;
1031 }
1032 
1033 /*
1034  * Return the available trace data in the buffer (starts at etr_buf->offset,
1035  * limited by etr_buf->len) from @pos, with a maximum limit of @len,
1036  * also updating the @bufpp on where to find it. Since the trace data
1037  * starts at anywhere in the buffer, depending on the RRP, we adjust the
1038  * @len returned to handle buffer wrapping around.
1039  *
1040  * We are protected here by drvdata->reading != 0, which ensures the
1041  * sysfs_buf stays alive.
1042  */
1043 ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata,
1044                                 loff_t pos, size_t len, char **bufpp)
1045 {
1046         s64 offset;
1047         ssize_t actual = len;
1048         struct etr_buf *etr_buf = drvdata->sysfs_buf;
1049 
1050         if (pos + actual > etr_buf->len)
1051                 actual = etr_buf->len - pos;
1052         if (actual <= 0)
1053                 return actual;
1054 
1055         /* Compute the offset from which we read the data */
1056         offset = etr_buf->offset + pos;
1057         if (offset >= etr_buf->size)
1058                 offset -= etr_buf->size;
1059         return tmc_etr_buf_get_data(etr_buf, offset, actual, bufpp);
1060 }
1061 
1062 static struct etr_buf *
1063 tmc_etr_setup_sysfs_buf(struct tmc_drvdata *drvdata)
1064 {
1065         return tmc_alloc_etr_buf(drvdata, drvdata->size,
1066                                  0, cpu_to_node(0), NULL);
1067 }
1068 
1069 static void
1070 tmc_etr_free_sysfs_buf(struct etr_buf *buf)
1071 {
1072         if (buf)
1073                 tmc_free_etr_buf(buf);
1074 }
1075 
1076 static void tmc_etr_sync_sysfs_buf(struct tmc_drvdata *drvdata)
1077 {
1078         struct etr_buf *etr_buf = drvdata->etr_buf;
1079 
1080         if (WARN_ON(drvdata->sysfs_buf != etr_buf)) {
1081                 tmc_etr_free_sysfs_buf(drvdata->sysfs_buf);
1082                 drvdata->sysfs_buf = NULL;
1083         } else {
1084                 tmc_sync_etr_buf(drvdata);
1085                 /*
1086                  * Insert barrier packets at the beginning, if there was
1087                  * an overflow.
1088                  */
1089                 if (etr_buf->full)
1090                         tmc_etr_buf_insert_barrier_packet(etr_buf,
1091                                                           etr_buf->offset);
1092         }
1093 }
1094 
1095 static void __tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
1096 {
1097         CS_UNLOCK(drvdata->base);
1098 
1099         tmc_flush_and_stop(drvdata);
1100         /*
1101          * When operating in sysFS mode the content of the buffer needs to be
1102          * read before the TMC is disabled.
1103          */
1104         if (drvdata->mode == CS_MODE_SYSFS)
1105                 tmc_etr_sync_sysfs_buf(drvdata);
1106 
1107         tmc_disable_hw(drvdata);
1108 
1109         CS_LOCK(drvdata->base);
1110 
1111 }
1112 
1113 static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
1114 {
1115         __tmc_etr_disable_hw(drvdata);
1116         /* Disable CATU device if this ETR is connected to one */
1117         tmc_etr_disable_catu(drvdata);
1118         coresight_disclaim_device(drvdata->base);
1119         /* Reset the ETR buf used by hardware */
1120         drvdata->etr_buf = NULL;
1121 }
1122 
1123 static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
1124 {
1125         int ret = 0;
1126         unsigned long flags;
1127         struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
1128         struct etr_buf *sysfs_buf = NULL, *new_buf = NULL, *free_buf = NULL;
1129 
1130         /*
1131          * If we are enabling the ETR from disabled state, we need to make
1132          * sure we have a buffer with the right size. The etr_buf is not reset
1133          * immediately after we stop the tracing in SYSFS mode as we wait for
1134          * the user to collect the data. We may be able to reuse the existing
1135          * buffer, provided the size matches. Any allocation has to be done
1136          * with the lock released.
1137          */
1138         spin_lock_irqsave(&drvdata->spinlock, flags);
1139         sysfs_buf = READ_ONCE(drvdata->sysfs_buf);
1140         if (!sysfs_buf || (sysfs_buf->size != drvdata->size)) {
1141                 spin_unlock_irqrestore(&drvdata->spinlock, flags);
1142 
1143                 /* Allocate memory with the locks released */
1144                 free_buf = new_buf = tmc_etr_setup_sysfs_buf(drvdata);
1145                 if (IS_ERR(new_buf))
1146                         return PTR_ERR(new_buf);
1147 
1148                 /* Let's try again */
1149                 spin_lock_irqsave(&drvdata->spinlock, flags);
1150         }
1151 
1152         if (drvdata->reading || drvdata->mode == CS_MODE_PERF) {
1153                 ret = -EBUSY;
1154                 goto out;
1155         }
1156 
1157         /*
1158          * In sysFS mode we can have multiple writers per sink.  Since this
1159          * sink is already enabled no memory is needed and the HW need not be
1160          * touched, even if the buffer size has changed.
1161          */
1162         if (drvdata->mode == CS_MODE_SYSFS) {
1163                 atomic_inc(csdev->refcnt);
1164                 goto out;
1165         }
1166 
1167         /*
1168          * If we don't have a buffer or it doesn't match the requested size,
1169          * use the buffer allocated above. Otherwise reuse the existing buffer.
1170          */
1171         sysfs_buf = READ_ONCE(drvdata->sysfs_buf);
1172         if (!sysfs_buf || (new_buf && sysfs_buf->size != new_buf->size)) {
1173                 free_buf = sysfs_buf;
1174                 drvdata->sysfs_buf = new_buf;
1175         }
1176 
1177         ret = tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf);
1178         if (!ret) {
1179                 drvdata->mode = CS_MODE_SYSFS;
1180                 atomic_inc(csdev->refcnt);
1181         }
1182 out:
1183         spin_unlock_irqrestore(&drvdata->spinlock, flags);
1184 
1185         /* Free memory outside the spinlock if need be */
1186         if (free_buf)
1187                 tmc_etr_free_sysfs_buf(free_buf);
1188 
1189         if (!ret)
1190                 dev_dbg(&csdev->dev, "TMC-ETR enabled\n");
1191 
1192         return ret;
1193 }
1194 
1195 /*
1196  * alloc_etr_buf: Allocate ETR buffer for use by perf.
1197  * The size of the hardware buffer is dependent on the size configured
1198  * via sysfs and the perf ring buffer size. We prefer to allocate the
1199  * largest possible size, scaling down the size by half until it
1200  * reaches a minimum limit (1M), beyond which we give up.
1201  */
1202 static struct etr_buf *
1203 alloc_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event,
1204               int nr_pages, void **pages, bool snapshot)
1205 {
1206         int node;
1207         struct etr_buf *etr_buf;
1208         unsigned long size;
1209 
1210         node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
1211         /*
1212          * Try to match the perf ring buffer size if it is larger
1213          * than the size requested via sysfs.
1214          */
1215         if ((nr_pages << PAGE_SHIFT) > drvdata->size) {
1216                 etr_buf = tmc_alloc_etr_buf(drvdata, (nr_pages << PAGE_SHIFT),
1217                                             0, node, NULL);
1218                 if (!IS_ERR(etr_buf))
1219                         goto done;
1220         }
1221 
1222         /*
1223          * Else switch to configured size for this ETR
1224          * and scale down until we hit the minimum limit.
1225          */
1226         size = drvdata->size;
1227         do {
1228                 etr_buf = tmc_alloc_etr_buf(drvdata, size, 0, node, NULL);
1229                 if (!IS_ERR(etr_buf))
1230                         goto done;
1231                 size /= 2;
1232         } while (size >= TMC_ETR_PERF_MIN_BUF_SIZE);
1233 
1234         return ERR_PTR(-ENOMEM);
1235 
1236 done:
1237         return etr_buf;
1238 }
1239 
1240 static struct etr_buf *
1241 get_perf_etr_buf_cpu_wide(struct tmc_drvdata *drvdata,
1242                           struct perf_event *event, int nr_pages,
1243                           void **pages, bool snapshot)
1244 {
1245         int ret;
1246         pid_t pid = task_pid_nr(event->owner);
1247         struct etr_buf *etr_buf;
1248 
1249 retry:
1250         /*
1251          * An etr_perf_buffer is associated with an event and holds a reference
1252          * to the AUX ring buffer that was created for that event.  In CPU-wide
1253          * N:1 mode multiple events (one per CPU), each with its own AUX ring
1254          * buffer, share a sink.  As such an etr_perf_buffer is created for each
1255          * event but a single etr_buf associated with the ETR is shared between
1256          * them.  The last event in a trace session will copy the content of the
1257          * etr_buf to its AUX ring buffer.  Ring buffer associated to other
1258          * events are simply not used an freed as events are destoyed.  We still
1259          * need to allocate a ring buffer for each event since we don't know
1260          * which event will be last.
1261          */
1262 
1263         /*
1264          * The first thing to do here is check if an etr_buf has already been
1265          * allocated for this session.  If so it is shared with this event,
1266          * otherwise it is created.
1267          */
1268         mutex_lock(&drvdata->idr_mutex);
1269         etr_buf = idr_find(&drvdata->idr, pid);
1270         if (etr_buf) {
1271                 refcount_inc(&etr_buf->refcount);
1272                 mutex_unlock(&drvdata->idr_mutex);
1273                 return etr_buf;
1274         }
1275 
1276         /* If we made it here no buffer has been allocated, do so now. */
1277         mutex_unlock(&drvdata->idr_mutex);
1278 
1279         etr_buf = alloc_etr_buf(drvdata, event, nr_pages, pages, snapshot);
1280         if (IS_ERR(etr_buf))
1281                 return etr_buf;
1282 
1283         /* Now that we have a buffer, add it to the IDR. */
1284         mutex_lock(&drvdata->idr_mutex);
1285         ret = idr_alloc(&drvdata->idr, etr_buf, pid, pid + 1, GFP_KERNEL);
1286         mutex_unlock(&drvdata->idr_mutex);
1287 
1288         /* Another event with this session ID has allocated this buffer. */
1289         if (ret == -ENOSPC) {
1290                 tmc_free_etr_buf(etr_buf);
1291                 goto retry;
1292         }
1293 
1294         /* The IDR can't allocate room for a new session, abandon ship. */
1295         if (ret == -ENOMEM) {
1296                 tmc_free_etr_buf(etr_buf);
1297                 return ERR_PTR(ret);
1298         }
1299 
1300 
1301         return etr_buf;
1302 }
1303 
1304 static struct etr_buf *
1305 get_perf_etr_buf_per_thread(struct tmc_drvdata *drvdata,
1306                             struct perf_event *event, int nr_pages,
1307                             void **pages, bool snapshot)
1308 {
1309         /*
1310          * In per-thread mode the etr_buf isn't shared, so just go ahead
1311          * with memory allocation.
1312          */
1313         return alloc_etr_buf(drvdata, event, nr_pages, pages, snapshot);
1314 }
1315 
1316 static struct etr_buf *
1317 get_perf_etr_buf(struct tmc_drvdata *drvdata, struct perf_event *event,
1318                  int nr_pages, void **pages, bool snapshot)
1319 {
1320         if (event->cpu == -1)
1321                 return get_perf_etr_buf_per_thread(drvdata, event, nr_pages,
1322                                                    pages, snapshot);
1323 
1324         return get_perf_etr_buf_cpu_wide(drvdata, event, nr_pages,
1325                                          pages, snapshot);
1326 }
1327 
1328 static struct etr_perf_buffer *
1329 tmc_etr_setup_perf_buf(struct tmc_drvdata *drvdata, struct perf_event *event,
1330                        int nr_pages, void **pages, bool snapshot)
1331 {
1332         int node;
1333         struct etr_buf *etr_buf;
1334         struct etr_perf_buffer *etr_perf;
1335 
1336         node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
1337 
1338         etr_perf = kzalloc_node(sizeof(*etr_perf), GFP_KERNEL, node);
1339         if (!etr_perf)
1340                 return ERR_PTR(-ENOMEM);
1341 
1342         etr_buf = get_perf_etr_buf(drvdata, event, nr_pages, pages, snapshot);
1343         if (!IS_ERR(etr_buf))
1344                 goto done;
1345 
1346         kfree(etr_perf);
1347         return ERR_PTR(-ENOMEM);
1348 
1349 done:
1350         /*
1351          * Keep a reference to the ETR this buffer has been allocated for
1352          * in order to have access to the IDR in tmc_free_etr_buffer().
1353          */
1354         etr_perf->drvdata = drvdata;
1355         etr_perf->etr_buf = etr_buf;
1356 
1357         return etr_perf;
1358 }
1359 
1360 
1361 static void *tmc_alloc_etr_buffer(struct coresight_device *csdev,
1362                                   struct perf_event *event, void **pages,
1363                                   int nr_pages, bool snapshot)
1364 {
1365         struct etr_perf_buffer *etr_perf;
1366         struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
1367 
1368         etr_perf = tmc_etr_setup_perf_buf(drvdata, event,
1369                                           nr_pages, pages, snapshot);
1370         if (IS_ERR(etr_perf)) {
1371                 dev_dbg(&csdev->dev, "Unable to allocate ETR buffer\n");
1372                 return NULL;
1373         }
1374 
1375         etr_perf->pid = task_pid_nr(event->owner);
1376         etr_perf->snapshot = snapshot;
1377         etr_perf->nr_pages = nr_pages;
1378         etr_perf->pages = pages;
1379 
1380         return etr_perf;
1381 }
1382 
1383 static void tmc_free_etr_buffer(void *config)
1384 {
1385         struct etr_perf_buffer *etr_perf = config;
1386         struct tmc_drvdata *drvdata = etr_perf->drvdata;
1387         struct etr_buf *buf, *etr_buf = etr_perf->etr_buf;
1388 
1389         if (!etr_buf)
1390                 goto free_etr_perf_buffer;
1391 
1392         mutex_lock(&drvdata->idr_mutex);
1393         /* If we are not the last one to use the buffer, don't touch it. */
1394         if (!refcount_dec_and_test(&etr_buf->refcount)) {
1395                 mutex_unlock(&drvdata->idr_mutex);
1396                 goto free_etr_perf_buffer;
1397         }
1398 
1399         /* We are the last one, remove from the IDR and free the buffer. */
1400         buf = idr_remove(&drvdata->idr, etr_perf->pid);
1401         mutex_unlock(&drvdata->idr_mutex);
1402 
1403         /*
1404          * Something went very wrong if the buffer associated with this ID
1405          * is not the same in the IDR.  Leak to avoid use after free.
1406          */
1407         if (buf && WARN_ON(buf != etr_buf))
1408                 goto free_etr_perf_buffer;
1409 
1410         tmc_free_etr_buf(etr_perf->etr_buf);
1411 
1412 free_etr_perf_buffer:
1413         kfree(etr_perf);
1414 }
1415 
1416 /*
1417  * tmc_etr_sync_perf_buffer: Copy the actual trace data from the hardware
1418  * buffer to the perf ring buffer.
1419  */
1420 static void tmc_etr_sync_perf_buffer(struct etr_perf_buffer *etr_perf,
1421                                      unsigned long src_offset,
1422                                      unsigned long to_copy)
1423 {
1424         long bytes;
1425         long pg_idx, pg_offset;
1426         unsigned long head = etr_perf->head;
1427         char **dst_pages, *src_buf;
1428         struct etr_buf *etr_buf = etr_perf->etr_buf;
1429 
1430         head = etr_perf->head;
1431         pg_idx = head >> PAGE_SHIFT;
1432         pg_offset = head & (PAGE_SIZE - 1);
1433         dst_pages = (char **)etr_perf->pages;
1434 
1435         while (to_copy > 0) {
1436                 /*
1437                  * In one iteration, we can copy minimum of :
1438                  *  1) what is available in the source buffer,
1439                  *  2) what is available in the source buffer, before it
1440                  *     wraps around.
1441                  *  3) what is available in the destination page.
1442                  * in one iteration.
1443                  */
1444                 if (src_offset >= etr_buf->size)
1445                         src_offset -= etr_buf->size;
1446                 bytes = tmc_etr_buf_get_data(etr_buf, src_offset, to_copy,
1447                                              &src_buf);
1448                 if (WARN_ON_ONCE(bytes <= 0))
1449                         break;
1450                 bytes = min(bytes, (long)(PAGE_SIZE - pg_offset));
1451 
1452                 memcpy(dst_pages[pg_idx] + pg_offset, src_buf, bytes);
1453 
1454                 to_copy -= bytes;
1455 
1456                 /* Move destination pointers */
1457                 pg_offset += bytes;
1458                 if (pg_offset == PAGE_SIZE) {
1459                         pg_offset = 0;
1460                         if (++pg_idx == etr_perf->nr_pages)
1461                                 pg_idx = 0;
1462                 }
1463 
1464                 /* Move source pointers */
1465                 src_offset += bytes;
1466         }
1467 }
1468 
1469 /*
1470  * tmc_update_etr_buffer : Update the perf ring buffer with the
1471  * available trace data. We use software double buffering at the moment.
1472  *
1473  * TODO: Add support for reusing the perf ring buffer.
1474  */
1475 static unsigned long
1476 tmc_update_etr_buffer(struct coresight_device *csdev,
1477                       struct perf_output_handle *handle,
1478                       void *config)
1479 {
1480         bool lost = false;
1481         unsigned long flags, offset, size = 0;
1482         struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
1483         struct etr_perf_buffer *etr_perf = config;
1484         struct etr_buf *etr_buf = etr_perf->etr_buf;
1485 
1486         spin_lock_irqsave(&drvdata->spinlock, flags);
1487 
1488         /* Don't do anything if another tracer is using this sink */
1489         if (atomic_read(csdev->refcnt) != 1) {
1490                 spin_unlock_irqrestore(&drvdata->spinlock, flags);
1491                 goto out;
1492         }
1493 
1494         if (WARN_ON(drvdata->perf_buf != etr_buf)) {
1495                 lost = true;
1496                 spin_unlock_irqrestore(&drvdata->spinlock, flags);
1497                 goto out;
1498         }
1499 
1500         CS_UNLOCK(drvdata->base);
1501 
1502         tmc_flush_and_stop(drvdata);
1503         tmc_sync_etr_buf(drvdata);
1504 
1505         CS_LOCK(drvdata->base);
1506         spin_unlock_irqrestore(&drvdata->spinlock, flags);
1507 
1508         lost = etr_buf->full;
1509         offset = etr_buf->offset;
1510         size = etr_buf->len;
1511 
1512         /*
1513          * The ETR buffer may be bigger than the space available in the
1514          * perf ring buffer (handle->size).  If so advance the offset so that we
1515          * get the latest trace data.  In snapshot mode none of that matters
1516          * since we are expected to clobber stale data in favour of the latest
1517          * traces.
1518          */
1519         if (!etr_perf->snapshot && size > handle->size) {
1520                 u32 mask = tmc_get_memwidth_mask(drvdata);
1521 
1522                 /*
1523                  * Make sure the new size is aligned in accordance with the
1524                  * requirement explained in function tmc_get_memwidth_mask().
1525                  */
1526                 size = handle->size & mask;
1527                 offset = etr_buf->offset + etr_buf->len - size;
1528 
1529                 if (offset >= etr_buf->size)
1530                         offset -= etr_buf->size;
1531                 lost = true;
1532         }
1533 
1534         /* Insert barrier packets at the beginning, if there was an overflow */
1535         if (lost)
1536                 tmc_etr_buf_insert_barrier_packet(etr_buf, etr_buf->offset);
1537         tmc_etr_sync_perf_buffer(etr_perf, offset, size);
1538 
1539         /*
1540          * In snapshot mode we simply increment the head by the number of byte
1541          * that were written.  User space function  cs_etm_find_snapshot() will
1542          * figure out how many bytes to get from the AUX buffer based on the
1543          * position of the head.
1544          */
1545         if (etr_perf->snapshot)
1546                 handle->head += size;
1547 out:
1548         /*
1549          * Don't set the TRUNCATED flag in snapshot mode because 1) the
1550          * captured buffer is expected to be truncated and 2) a full buffer
1551          * prevents the event from being re-enabled by the perf core,
1552          * resulting in stale data being send to user space.
1553          */
1554         if (!etr_perf->snapshot && lost)
1555                 perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
1556         return size;
1557 }
1558 
1559 static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
1560 {
1561         int rc = 0;
1562         pid_t pid;
1563         unsigned long flags;
1564         struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
1565         struct perf_output_handle *handle = data;
1566         struct etr_perf_buffer *etr_perf = etm_perf_sink_config(handle);
1567 
1568         spin_lock_irqsave(&drvdata->spinlock, flags);
1569          /* Don't use this sink if it is already claimed by sysFS */
1570         if (drvdata->mode == CS_MODE_SYSFS) {
1571                 rc = -EBUSY;
1572                 goto unlock_out;
1573         }
1574 
1575         if (WARN_ON(!etr_perf || !etr_perf->etr_buf)) {
1576                 rc = -EINVAL;
1577                 goto unlock_out;
1578         }
1579 
1580         /* Get a handle on the pid of the process to monitor */
1581         pid = etr_perf->pid;
1582 
1583         /* Do not proceed if this device is associated with another session */
1584         if (drvdata->pid != -1 && drvdata->pid != pid) {
1585                 rc = -EBUSY;
1586                 goto unlock_out;
1587         }
1588 
1589         etr_perf->head = PERF_IDX2OFF(handle->head, etr_perf);
1590 
1591         /*
1592          * No HW configuration is needed if the sink is already in
1593          * use for this session.
1594          */
1595         if (drvdata->pid == pid) {
1596                 atomic_inc(csdev->refcnt);
1597                 goto unlock_out;
1598         }
1599 
1600         rc = tmc_etr_enable_hw(drvdata, etr_perf->etr_buf);
1601         if (!rc) {
1602                 /* Associate with monitored process. */
1603                 drvdata->pid = pid;
1604                 drvdata->mode = CS_MODE_PERF;
1605                 drvdata->perf_buf = etr_perf->etr_buf;
1606                 atomic_inc(csdev->refcnt);
1607         }
1608 
1609 unlock_out:
1610         spin_unlock_irqrestore(&drvdata->spinlock, flags);
1611         return rc;
1612 }
1613 
1614 static int tmc_enable_etr_sink(struct coresight_device *csdev,
1615                                u32 mode, void *data)
1616 {
1617         switch (mode) {
1618         case CS_MODE_SYSFS:
1619                 return tmc_enable_etr_sink_sysfs(csdev);
1620         case CS_MODE_PERF:
1621                 return tmc_enable_etr_sink_perf(csdev, data);
1622         }
1623 
1624         /* We shouldn't be here */
1625         return -EINVAL;
1626 }
1627 
1628 static int tmc_disable_etr_sink(struct coresight_device *csdev)
1629 {
1630         unsigned long flags;
1631         struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
1632 
1633         spin_lock_irqsave(&drvdata->spinlock, flags);
1634 
1635         if (drvdata->reading) {
1636                 spin_unlock_irqrestore(&drvdata->spinlock, flags);
1637                 return -EBUSY;
1638         }
1639 
1640         if (atomic_dec_return(csdev->refcnt)) {
1641                 spin_unlock_irqrestore(&drvdata->spinlock, flags);
1642                 return -EBUSY;
1643         }
1644 
1645         /* Complain if we (somehow) got out of sync */
1646         WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
1647         tmc_etr_disable_hw(drvdata);
1648         /* Dissociate from monitored process. */
1649         drvdata->pid = -1;
1650         drvdata->mode = CS_MODE_DISABLED;
1651         /* Reset perf specific data */
1652         drvdata->perf_buf = NULL;
1653 
1654         spin_unlock_irqrestore(&drvdata->spinlock, flags);
1655 
1656         dev_dbg(&csdev->dev, "TMC-ETR disabled\n");
1657         return 0;
1658 }
1659 
1660 static const struct coresight_ops_sink tmc_etr_sink_ops = {
1661         .enable         = tmc_enable_etr_sink,
1662         .disable        = tmc_disable_etr_sink,
1663         .alloc_buffer   = tmc_alloc_etr_buffer,
1664         .update_buffer  = tmc_update_etr_buffer,
1665         .free_buffer    = tmc_free_etr_buffer,
1666 };
1667 
1668 const struct coresight_ops tmc_etr_cs_ops = {
1669         .sink_ops       = &tmc_etr_sink_ops,
1670 };
1671 
1672 int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
1673 {
1674         int ret = 0;
1675         unsigned long flags;
1676 
1677         /* config types are set a boot time and never change */
1678         if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
1679                 return -EINVAL;
1680 
1681         spin_lock_irqsave(&drvdata->spinlock, flags);
1682         if (drvdata->reading) {
1683                 ret = -EBUSY;
1684                 goto out;
1685         }
1686 
1687         /*
1688          * We can safely allow reads even if the ETR is operating in PERF mode,
1689          * since the sysfs session is captured in mode specific data.
1690          * If drvdata::sysfs_data is NULL the trace data has been read already.
1691          */
1692         if (!drvdata->sysfs_buf) {
1693                 ret = -EINVAL;
1694                 goto out;
1695         }
1696 
1697         /* Disable the TMC if we are trying to read from a running session. */
1698         if (drvdata->mode == CS_MODE_SYSFS)
1699                 __tmc_etr_disable_hw(drvdata);
1700 
1701         drvdata->reading = true;
1702 out:
1703         spin_unlock_irqrestore(&drvdata->spinlock, flags);
1704 
1705         return ret;
1706 }
1707 
1708 int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
1709 {
1710         unsigned long flags;
1711         struct etr_buf *sysfs_buf = NULL;
1712 
1713         /* config types are set a boot time and never change */
1714         if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR))
1715                 return -EINVAL;
1716 
1717         spin_lock_irqsave(&drvdata->spinlock, flags);
1718 
1719         /* RE-enable the TMC if need be */
1720         if (drvdata->mode == CS_MODE_SYSFS) {
1721                 /*
1722                  * The trace run will continue with the same allocated trace
1723                  * buffer. Since the tracer is still enabled drvdata::buf can't
1724                  * be NULL.
1725                  */
1726                 __tmc_etr_enable_hw(drvdata);
1727         } else {
1728                 /*
1729                  * The ETR is not tracing and the buffer was just read.
1730                  * As such prepare to free the trace buffer.
1731                  */
1732                 sysfs_buf = drvdata->sysfs_buf;
1733                 drvdata->sysfs_buf = NULL;
1734         }
1735 
1736         drvdata->reading = false;
1737         spin_unlock_irqrestore(&drvdata->spinlock, flags);
1738 
1739         /* Free allocated memory out side of the spinlock */
1740         if (sysfs_buf)
1741                 tmc_etr_free_sysfs_buf(sysfs_buf);
1742 
1743         return 0;
1744 }
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/hwtracing/coresight/coresight-tmc-etr.c

DEFINITIONS
