/* * Copyright © 2017 Intel Corporation * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ /** * @file crocus_bufmgr.c * * The crocus buffer manager. * * XXX: write better comments * - BOs * - Explain BO cache * - main interface to GEM in the kernel */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "errno.h" #include "common/intel_clflush.h" #include "dev/intel_debug.h" #include "common/intel_gem.h" #include "dev/intel_device_info.h" #include "main/macros.h" #include "util/debug.h" #include "util/macros.h" #include "util/hash_table.h" #include "util/list.h" #include "util/os_file.h" #include "util/u_dynarray.h" #include "util/vma.h" #include "crocus_bufmgr.h" #include "crocus_context.h" #include "string.h" #include "drm-uapi/i915_drm.h" #ifdef HAVE_VALGRIND #include #include #define VG(x) x #else #define VG(x) #endif /** * For debugging purposes, this returns a time in seconds. */ static double get_time(void) { struct timespec tp; clock_gettime(CLOCK_MONOTONIC, &tp); return tp.tv_sec + tp.tv_nsec / 1000000000.0; } /* VALGRIND_FREELIKE_BLOCK unfortunately does not actually undo the earlier * VALGRIND_MALLOCLIKE_BLOCK but instead leaves vg convinced the memory is * leaked. All because it does not call VG(cli_free) from its * VG_USERREQ__FREELIKE_BLOCK handler. Instead of treating the memory like * and allocation, we mark it available for use upon mmapping and remove * it upon unmapping. */ #define VG_DEFINED(ptr, size) VG(VALGRIND_MAKE_MEM_DEFINED(ptr, size)) #define VG_NOACCESS(ptr, size) VG(VALGRIND_MAKE_MEM_NOACCESS(ptr, size)) #define PAGE_SIZE 4096 #define WARN_ONCE(cond, fmt...) do { \ if (unlikely(cond)) { \ static bool _warned = false; \ if (!_warned) { \ fprintf(stderr, "WARNING: "); \ fprintf(stderr, fmt); \ _warned = true; \ } \ } \ } while (0) #define FILE_DEBUG_FLAG DEBUG_BUFMGR struct bo_cache_bucket { /** List of cached BOs. */ struct list_head head; /** Size of this bucket, in bytes. */ uint64_t size; }; struct bo_export { /** File descriptor associated with a handle export. */ int drm_fd; /** GEM handle in drm_fd */ uint32_t gem_handle; struct list_head link; }; struct crocus_bufmgr { /** * List into the list of bufmgr. */ struct list_head link; uint32_t refcount; int fd; simple_mtx_t lock; /** Array of lists of cached gem objects of power-of-two sizes */ struct bo_cache_bucket cache_bucket[14 * 4]; int num_buckets; time_t time; struct hash_table *name_table; struct hash_table *handle_table; /** * List of BOs which we've effectively freed, but are hanging on to * until they're idle before closing and returning the VMA. */ struct list_head zombie_list; bool has_llc:1; bool has_mmap_offset:1; bool has_tiling_uapi:1; bool bo_reuse:1; }; static simple_mtx_t global_bufmgr_list_mutex = _SIMPLE_MTX_INITIALIZER_NP; static struct list_head global_bufmgr_list = { .next = &global_bufmgr_list, .prev = &global_bufmgr_list, }; static int bo_set_tiling_internal(struct crocus_bo *bo, uint32_t tiling_mode, uint32_t stride); static void bo_free(struct crocus_bo *bo); static uint32_t key_hash_uint(const void *key) { return _mesa_hash_data(key, 4); } static bool key_uint_equal(const void *a, const void *b) { return *((unsigned *) a) == *((unsigned *) b); } static struct crocus_bo * find_and_ref_external_bo(struct hash_table *ht, unsigned int key) { struct hash_entry *entry = _mesa_hash_table_search(ht, &key); struct crocus_bo *bo = entry ? entry->data : NULL; if (bo) { assert(bo->external); assert(!bo->reusable); /* Being non-reusable, the BO cannot be in the cache lists, but it * may be in the zombie list if it had reached zero references, but * we hadn't yet closed it...and then reimported the same BO. If it * is, then remove it since it's now been resurrected. */ if (bo->head.prev || bo->head.next) list_del(&bo->head); crocus_bo_reference(bo); } return bo; } /** * This function finds the correct bucket fit for the input size. * The function works with O(1) complexity when the requested size * was queried instead of iterating the size through all the buckets. */ static struct bo_cache_bucket * bucket_for_size(struct crocus_bufmgr *bufmgr, uint64_t size) { /* Calculating the pages and rounding up to the page size. */ const unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE; /* Row Bucket sizes clz((x-1) | 3) Row Column * in pages stride size * 0: 1 2 3 4 -> 30 30 30 30 4 1 * 1: 5 6 7 8 -> 29 29 29 29 4 1 * 2: 10 12 14 16 -> 28 28 28 28 8 2 * 3: 20 24 28 32 -> 27 27 27 27 16 4 */ const unsigned row = 30 - __builtin_clz((pages - 1) | 3); const unsigned row_max_pages = 4 << row; /* The '& ~2' is the special case for row 1. In row 1, max pages / * 2 is 2, but the previous row maximum is zero (because there is * no previous row). All row maximum sizes are power of 2, so that * is the only case where that bit will be set. */ const unsigned prev_row_max_pages = (row_max_pages / 2) & ~2; int col_size_log2 = row - 1; col_size_log2 += (col_size_log2 < 0); const unsigned col = (pages - prev_row_max_pages + ((1 << col_size_log2) - 1)) >> col_size_log2; /* Calculating the index based on the row and column. */ const unsigned index = (row * 4) + (col - 1); return (index < bufmgr->num_buckets) ? &bufmgr->cache_bucket[index] : NULL; } int crocus_bo_busy(struct crocus_bo *bo) { struct crocus_bufmgr *bufmgr = bo->bufmgr; struct drm_i915_gem_busy busy = { .handle = bo->gem_handle }; int ret = intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_BUSY, &busy); if (ret == 0) { bo->idle = !busy.busy; return busy.busy; } return false; } int crocus_bo_madvise(struct crocus_bo *bo, int state) { struct drm_i915_gem_madvise madv = { .handle = bo->gem_handle, .madv = state, .retained = 1, }; intel_ioctl(bo->bufmgr->fd, DRM_IOCTL_I915_GEM_MADVISE, &madv); return madv.retained; } static struct crocus_bo * bo_calloc(void) { struct crocus_bo *bo = calloc(1, sizeof(*bo)); if (!bo) return NULL; list_inithead(&bo->exports); bo->hash = _mesa_hash_pointer(bo); return bo; } static struct crocus_bo * alloc_bo_from_cache(struct crocus_bufmgr *bufmgr, struct bo_cache_bucket *bucket, uint32_t alignment, unsigned flags) { if (!bucket) return NULL; struct crocus_bo *bo = NULL; list_for_each_entry_safe(struct crocus_bo, cur, &bucket->head, head) { /* If the last BO in the cache is busy, there are no idle BOs. Bail, * either falling back to a non-matching memzone, or if that fails, * allocating a fresh buffer. */ if (crocus_bo_busy(cur)) return NULL; list_del(&cur->head); /* Tell the kernel we need this BO. If it still exists, we're done! */ if (crocus_bo_madvise(cur, I915_MADV_WILLNEED)) { bo = cur; break; } /* This BO was purged, throw it out and keep looking. */ bo_free(cur); } if (!bo) return NULL; /* Zero the contents if necessary. If this fails, fall back to * allocating a fresh BO, which will always be zeroed by the kernel. */ if (flags & BO_ALLOC_ZEROED) { void *map = crocus_bo_map(NULL, bo, MAP_WRITE | MAP_RAW); if (map) { memset(map, 0, bo->size); } else { bo_free(bo); return NULL; } } return bo; } static struct crocus_bo * alloc_fresh_bo(struct crocus_bufmgr *bufmgr, uint64_t bo_size) { struct crocus_bo *bo = bo_calloc(); if (!bo) return NULL; struct drm_i915_gem_create create = { .size = bo_size }; /* All new BOs we get from the kernel are zeroed, so we don't need to * worry about that here. */ if (intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_CREATE, &create) != 0) { free(bo); return NULL; } bo->gem_handle = create.handle; bo->bufmgr = bufmgr; bo->size = bo_size; bo->idle = true; bo->tiling_mode = I915_TILING_NONE; bo->swizzle_mode = I915_BIT_6_SWIZZLE_NONE; bo->stride = 0; /* Calling set_domain() will allocate pages for the BO outside of the * struct mutex lock in the kernel, which is more efficient than waiting * to create them during the first execbuf that uses the BO. */ struct drm_i915_gem_set_domain sd = { .handle = bo->gem_handle, .read_domains = I915_GEM_DOMAIN_CPU, .write_domain = 0, }; if (intel_ioctl(bo->bufmgr->fd, DRM_IOCTL_I915_GEM_SET_DOMAIN, &sd) != 0) { bo_free(bo); return NULL; } return bo; } static struct crocus_bo * bo_alloc_internal(struct crocus_bufmgr *bufmgr, const char *name, uint64_t size, uint32_t alignment, unsigned flags, uint32_t tiling_mode, uint32_t stride) { struct crocus_bo *bo; unsigned int page_size = getpagesize(); struct bo_cache_bucket *bucket = bucket_for_size(bufmgr, size); /* Round the size up to the bucket size, or if we don't have caching * at this size, a multiple of the page size. */ uint64_t bo_size = bucket ? bucket->size : MAX2(ALIGN(size, page_size), page_size); simple_mtx_lock(&bufmgr->lock); /* Get a buffer out of the cache if available. First, we try to find * one with a matching memory zone so we can avoid reallocating VMA. */ bo = alloc_bo_from_cache(bufmgr, bucket, alignment, flags); simple_mtx_unlock(&bufmgr->lock); if (!bo) { bo = alloc_fresh_bo(bufmgr, bo_size); if (!bo) return NULL; } if (bo_set_tiling_internal(bo, tiling_mode, stride)) goto err_free; bo->name = name; p_atomic_set(&bo->refcount, 1); bo->reusable = bucket && bufmgr->bo_reuse; bo->cache_coherent = bufmgr->has_llc; bo->index = -1; bo->kflags = 0; if ((flags & BO_ALLOC_COHERENT) && !bo->cache_coherent) { struct drm_i915_gem_caching arg = { .handle = bo->gem_handle, .caching = 1, }; if (intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_SET_CACHING, &arg) == 0) { bo->cache_coherent = true; bo->reusable = false; } } DBG("bo_create: buf %d (%s) %llub\n", bo->gem_handle, bo->name, (unsigned long long) size); return bo; err_free: bo_free(bo); return NULL; } struct crocus_bo * crocus_bo_alloc(struct crocus_bufmgr *bufmgr, const char *name, uint64_t size) { return bo_alloc_internal(bufmgr, name, size, 1, 0, I915_TILING_NONE, 0); } struct crocus_bo * crocus_bo_alloc_tiled(struct crocus_bufmgr *bufmgr, const char *name, uint64_t size, uint32_t alignment, uint32_t tiling_mode, uint32_t pitch, unsigned flags) { return bo_alloc_internal(bufmgr, name, size, alignment, flags, tiling_mode, pitch); } struct crocus_bo * crocus_bo_create_userptr(struct crocus_bufmgr *bufmgr, const char *name, void *ptr, size_t size) { struct crocus_bo *bo; bo = bo_calloc(); if (!bo) return NULL; struct drm_i915_gem_userptr arg = { .user_ptr = (uintptr_t)ptr, .user_size = size, }; if (intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_USERPTR, &arg)) goto err_free; bo->gem_handle = arg.handle; /* Check the buffer for validity before we try and use it in a batch */ struct drm_i915_gem_set_domain sd = { .handle = bo->gem_handle, .read_domains = I915_GEM_DOMAIN_CPU, }; if (intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_SET_DOMAIN, &sd)) goto err_close; bo->name = name; bo->size = size; bo->map_cpu = ptr; bo->bufmgr = bufmgr; bo->kflags = 0; p_atomic_set(&bo->refcount, 1); bo->userptr = true; bo->cache_coherent = true; bo->index = -1; bo->idle = true; return bo; err_close: intel_ioctl(bufmgr->fd, DRM_IOCTL_GEM_CLOSE, &bo->gem_handle); err_free: free(bo); return NULL; } /** * Returns a crocus_bo wrapping the given buffer object handle. * * This can be used when one application needs to pass a buffer object * to another. */ struct crocus_bo * crocus_bo_gem_create_from_name(struct crocus_bufmgr *bufmgr, const char *name, unsigned int handle) { struct crocus_bo *bo; /* At the moment most applications only have a few named bo. * For instance, in a DRI client only the render buffers passed * between X and the client are named. And since X returns the * alternating names for the front/back buffer a linear search * provides a sufficiently fast match. */ simple_mtx_lock(&bufmgr->lock); bo = find_and_ref_external_bo(bufmgr->name_table, handle); if (bo) goto out; struct drm_gem_open open_arg = { .name = handle }; int ret = intel_ioctl(bufmgr->fd, DRM_IOCTL_GEM_OPEN, &open_arg); if (ret != 0) { DBG("Couldn't reference %s handle 0x%08x: %s\n", name, handle, strerror(errno)); bo = NULL; goto out; } /* Now see if someone has used a prime handle to get this * object from the kernel before by looking through the list * again for a matching gem_handle */ bo = find_and_ref_external_bo(bufmgr->handle_table, open_arg.handle); if (bo) goto out; bo = bo_calloc(); if (!bo) goto out; p_atomic_set(&bo->refcount, 1); bo->size = open_arg.size; bo->gtt_offset = 0; bo->bufmgr = bufmgr; bo->gem_handle = open_arg.handle; bo->name = name; bo->global_name = handle; bo->reusable = false; bo->external = true; bo->kflags = 0; _mesa_hash_table_insert(bufmgr->handle_table, &bo->gem_handle, bo); _mesa_hash_table_insert(bufmgr->name_table, &bo->global_name, bo); struct drm_i915_gem_get_tiling get_tiling = { .handle = bo->gem_handle }; ret = intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_GET_TILING, &get_tiling); if (ret != 0) goto err_unref; bo->tiling_mode = get_tiling.tiling_mode; bo->swizzle_mode = get_tiling.swizzle_mode; /* XXX stride is unknown */ DBG("bo_create_from_handle: %d (%s)\n", handle, bo->name); out: simple_mtx_unlock(&bufmgr->lock); return bo; err_unref: bo_free(bo); simple_mtx_unlock(&bufmgr->lock); return NULL; } static void bo_close(struct crocus_bo *bo) { struct crocus_bufmgr *bufmgr = bo->bufmgr; if (bo->external) { struct hash_entry *entry; if (bo->global_name) { entry = _mesa_hash_table_search(bufmgr->name_table, &bo->global_name); _mesa_hash_table_remove(bufmgr->name_table, entry); } entry = _mesa_hash_table_search(bufmgr->handle_table, &bo->gem_handle); _mesa_hash_table_remove(bufmgr->handle_table, entry); list_for_each_entry_safe(struct bo_export, export, &bo->exports, link) { struct drm_gem_close close = { .handle = export->gem_handle }; intel_ioctl(export->drm_fd, DRM_IOCTL_GEM_CLOSE, &close); list_del(&export->link); free(export); } } else { assert(list_is_empty(&bo->exports)); } /* Close this object */ struct drm_gem_close close = { .handle = bo->gem_handle }; int ret = intel_ioctl(bufmgr->fd, DRM_IOCTL_GEM_CLOSE, &close); if (ret != 0) { DBG("DRM_IOCTL_GEM_CLOSE %d failed (%s): %s\n", bo->gem_handle, bo->name, strerror(errno)); } free(bo); } static void bo_free(struct crocus_bo *bo) { struct crocus_bufmgr *bufmgr = bo->bufmgr; if (bo->map_cpu && !bo->userptr) { VG_NOACCESS(bo->map_cpu, bo->size); munmap(bo->map_cpu, bo->size); } if (bo->map_wc) { VG_NOACCESS(bo->map_wc, bo->size); munmap(bo->map_wc, bo->size); } if (bo->map_gtt) { VG_NOACCESS(bo->map_gtt, bo->size); munmap(bo->map_gtt, bo->size); } if (bo->idle) { bo_close(bo); } else { /* Defer closing the GEM BO and returning the VMA for reuse until the * BO is idle. Just move it to the dead list for now. */ list_addtail(&bo->head, &bufmgr->zombie_list); } } /** Frees all cached buffers significantly older than @time. */ static void cleanup_bo_cache(struct crocus_bufmgr *bufmgr, time_t time) { int i; if (bufmgr->time == time) return; for (i = 0; i < bufmgr->num_buckets; i++) { struct bo_cache_bucket *bucket = &bufmgr->cache_bucket[i]; list_for_each_entry_safe(struct crocus_bo, bo, &bucket->head, head) { if (time - bo->free_time <= 1) break; list_del(&bo->head); bo_free(bo); } } list_for_each_entry_safe(struct crocus_bo, bo, &bufmgr->zombie_list, head) { /* Stop once we reach a busy BO - all others past this point were * freed more recently so are likely also busy. */ if (!bo->idle && crocus_bo_busy(bo)) break; list_del(&bo->head); bo_close(bo); } bufmgr->time = time; } static void bo_unreference_final(struct crocus_bo *bo, time_t time) { struct crocus_bufmgr *bufmgr = bo->bufmgr; struct bo_cache_bucket *bucket; DBG("bo_unreference final: %d (%s)\n", bo->gem_handle, bo->name); bucket = NULL; if (bo->reusable) bucket = bucket_for_size(bufmgr, bo->size); /* Put the buffer into our internal cache for reuse if we can. */ if (bucket && crocus_bo_madvise(bo, I915_MADV_DONTNEED)) { bo->free_time = time; bo->name = NULL; list_addtail(&bo->head, &bucket->head); } else { bo_free(bo); } } void __crocus_bo_unreference(struct crocus_bo *bo) { struct crocus_bufmgr *bufmgr = bo->bufmgr; struct timespec time; clock_gettime(CLOCK_MONOTONIC, &time); simple_mtx_lock(&bufmgr->lock); if (p_atomic_dec_zero(&bo->refcount)) { bo_unreference_final(bo, time.tv_sec); cleanup_bo_cache(bufmgr, time.tv_sec); } simple_mtx_unlock(&bufmgr->lock); } static void bo_wait_with_stall_warning(struct pipe_debug_callback *dbg, struct crocus_bo *bo, const char *action) { bool busy = dbg && !bo->idle; double elapsed = unlikely(busy) ? -get_time() : 0.0; crocus_bo_wait_rendering(bo); if (unlikely(busy)) { elapsed += get_time(); if (elapsed > 1e-5) /* 0.01ms */ { perf_debug(dbg, "%s a busy \"%s\" BO stalled and took %.03f ms.\n", action, bo->name, elapsed * 1000); } } } static void print_flags(unsigned flags) { if (flags & MAP_READ) DBG("READ "); if (flags & MAP_WRITE) DBG("WRITE "); if (flags & MAP_ASYNC) DBG("ASYNC "); if (flags & MAP_PERSISTENT) DBG("PERSISTENT "); if (flags & MAP_COHERENT) DBG("COHERENT "); if (flags & MAP_RAW) DBG("RAW "); DBG("\n"); } static void * crocus_bo_gem_mmap_legacy(struct pipe_debug_callback *dbg, struct crocus_bo *bo, bool wc) { struct crocus_bufmgr *bufmgr = bo->bufmgr; struct drm_i915_gem_mmap mmap_arg = { .handle = bo->gem_handle, .size = bo->size, .flags = wc ? I915_MMAP_WC : 0, }; int ret = intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_MMAP, &mmap_arg); if (ret != 0) { DBG("%s:%d: Error mapping buffer %d (%s): %s .\n", __FILE__, __LINE__, bo->gem_handle, bo->name, strerror(errno)); return NULL; } void *map = (void *) (uintptr_t) mmap_arg.addr_ptr; return map; } static void * crocus_bo_gem_mmap_offset(struct pipe_debug_callback *dbg, struct crocus_bo *bo, bool wc) { struct crocus_bufmgr *bufmgr = bo->bufmgr; struct drm_i915_gem_mmap_offset mmap_arg = { .handle = bo->gem_handle, .flags = wc ? I915_MMAP_OFFSET_WC : I915_MMAP_OFFSET_WB, }; /* Get the fake offset back */ int ret = intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_MMAP_OFFSET, &mmap_arg); if (ret != 0) { DBG("%s:%d: Error preparing buffer %d (%s): %s .\n", __FILE__, __LINE__, bo->gem_handle, bo->name, strerror(errno)); return NULL; } /* And map it */ void *map = mmap(0, bo->size, PROT_READ | PROT_WRITE, MAP_SHARED, bufmgr->fd, mmap_arg.offset); if (map == MAP_FAILED) { DBG("%s:%d: Error mapping buffer %d (%s): %s .\n", __FILE__, __LINE__, bo->gem_handle, bo->name, strerror(errno)); return NULL; } return map; } static void * crocus_bo_gem_mmap(struct pipe_debug_callback *dbg, struct crocus_bo *bo, bool wc) { struct crocus_bufmgr *bufmgr = bo->bufmgr; if (bufmgr->has_mmap_offset) return crocus_bo_gem_mmap_offset(dbg, bo, wc); else return crocus_bo_gem_mmap_legacy(dbg, bo, wc); } static void * crocus_bo_map_cpu(struct pipe_debug_callback *dbg, struct crocus_bo *bo, unsigned flags) { /* We disallow CPU maps for writing to non-coherent buffers, as the * CPU map can become invalidated when a batch is flushed out, which * can happen at unpredictable times. You should use WC maps instead. */ assert(bo->cache_coherent || !(flags & MAP_WRITE)); if (!bo->map_cpu) { DBG("crocus_bo_map_cpu: %d (%s)\n", bo->gem_handle, bo->name); void *map = crocus_bo_gem_mmap(dbg, bo, false); if (!map) { return NULL; } VG_DEFINED(map, bo->size); if (p_atomic_cmpxchg(&bo->map_cpu, NULL, map)) { VG_NOACCESS(map, bo->size); munmap(map, bo->size); } } assert(bo->map_cpu); DBG("crocus_bo_map_cpu: %d (%s) -> %p, ", bo->gem_handle, bo->name, bo->map_cpu); print_flags(flags); if (!(flags & MAP_ASYNC)) { bo_wait_with_stall_warning(dbg, bo, "CPU mapping"); } if (!bo->cache_coherent && !bo->bufmgr->has_llc) { /* If we're reusing an existing CPU mapping, the CPU caches may * contain stale data from the last time we read from that mapping. * (With the BO cache, it might even be data from a previous buffer!) * Even if it's a brand new mapping, the kernel may have zeroed the * buffer via CPU writes. * * We need to invalidate those cachelines so that we see the latest * contents, and so long as we only read from the CPU mmap we do not * need to write those cachelines back afterwards. * * On LLC, the emprical evidence suggests that writes from the GPU * that bypass the LLC (i.e. for scanout) do *invalidate* the CPU * cachelines. (Other reads, such as the display engine, bypass the * LLC entirely requiring us to keep dirty pixels for the scanout * out of any cache.) */ intel_invalidate_range(bo->map_cpu, bo->size); } return bo->map_cpu; } static void * crocus_bo_map_wc(struct pipe_debug_callback *dbg, struct crocus_bo *bo, unsigned flags) { if (!bo->map_wc) { DBG("crocus_bo_map_wc: %d (%s)\n", bo->gem_handle, bo->name); void *map = crocus_bo_gem_mmap(dbg, bo, true); if (!map) { return NULL; } VG_DEFINED(map, bo->size); if (p_atomic_cmpxchg(&bo->map_wc, NULL, map)) { VG_NOACCESS(map, bo->size); munmap(map, bo->size); } } assert(bo->map_wc); DBG("crocus_bo_map_wc: %d (%s) -> %p\n", bo->gem_handle, bo->name, bo->map_wc); print_flags(flags); if (!(flags & MAP_ASYNC)) { bo_wait_with_stall_warning(dbg, bo, "WC mapping"); } return bo->map_wc; } /** * Perform an uncached mapping via the GTT. * * Write access through the GTT is not quite fully coherent. On low power * systems especially, like modern Atoms, we can observe reads from RAM before * the write via GTT has landed. A write memory barrier that flushes the Write * Combining Buffer (i.e. sfence/mfence) is not sufficient to order the later * read after the write as the GTT write suffers a small delay through the GTT * indirection. The kernel uses an uncached mmio read to ensure the GTT write * is ordered with reads (either by the GPU, WB or WC) and unconditionally * flushes prior to execbuf submission. However, if we are not informing the * kernel about our GTT writes, it will not flush before earlier access, such * as when using the cmdparser. Similarly, we need to be careful if we should * ever issue a CPU read immediately following a GTT write. * * Telling the kernel about write access also has one more important * side-effect. Upon receiving notification about the write, it cancels any * scanout buffering for FBC/PSR and friends. Later FBC/PSR is then flushed by * either SW_FINISH or DIRTYFB. The presumption is that we never write to the * actual scanout via a mmaping, only to a backbuffer and so all the FBC/PSR * tracking is handled on the buffer exchange instead. */ static void * crocus_bo_map_gtt(struct pipe_debug_callback *dbg, struct crocus_bo *bo, unsigned flags) { struct crocus_bufmgr *bufmgr = bo->bufmgr; /* If we don't support get/set_tiling, there's no support for GTT mapping * either (it won't do any de-tiling for us). */ assert(bufmgr->has_tiling_uapi); /* Get a mapping of the buffer if we haven't before. */ if (bo->map_gtt == NULL) { DBG("bo_map_gtt: mmap %d (%s)\n", bo->gem_handle, bo->name); struct drm_i915_gem_mmap_gtt mmap_arg = { .handle = bo->gem_handle }; /* Get the fake offset back... */ int ret = intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_MMAP_GTT, &mmap_arg); if (ret != 0) { DBG("%s:%d: Error preparing buffer map %d (%s): %s .\n", __FILE__, __LINE__, bo->gem_handle, bo->name, strerror(errno)); return NULL; } /* and mmap it. */ void *map = mmap(0, bo->size, PROT_READ | PROT_WRITE, MAP_SHARED, bufmgr->fd, mmap_arg.offset); if (map == MAP_FAILED) { DBG("%s:%d: Error mapping buffer %d (%s): %s .\n", __FILE__, __LINE__, bo->gem_handle, bo->name, strerror(errno)); return NULL; } /* We don't need to use VALGRIND_MALLOCLIKE_BLOCK because Valgrind will * already intercept this mmap call. However, for consistency between * all the mmap paths, we mark the pointer as defined now and mark it * as inaccessible afterwards. */ VG_DEFINED(map, bo->size); if (p_atomic_cmpxchg(&bo->map_gtt, NULL, map)) { VG_NOACCESS(map, bo->size); munmap(map, bo->size); } } assert(bo->map_gtt); DBG("bo_map_gtt: %d (%s) -> %p, ", bo->gem_handle, bo->name, bo->map_gtt); print_flags(flags); if (!(flags & MAP_ASYNC)) { bo_wait_with_stall_warning(dbg, bo, "GTT mapping"); } return bo->map_gtt; } static bool can_map_cpu(struct crocus_bo *bo, unsigned flags) { if (bo->cache_coherent) return true; /* Even if the buffer itself is not cache-coherent (such as a scanout), on * an LLC platform reads always are coherent (as they are performed via the * central system agent). It is just the writes that we need to take special * care to ensure that land in main memory and not stick in the CPU cache. */ if (!(flags & MAP_WRITE) && bo->bufmgr->has_llc) return true; /* If PERSISTENT or COHERENT are set, the mmapping needs to remain valid * across batch flushes where the kernel will change cache domains of the * bo, invalidating continued access to the CPU mmap on non-LLC device. * * Similarly, ASYNC typically means that the buffer will be accessed via * both the CPU and the GPU simultaneously. Batches may be executed that * use the BO even while it is mapped. While OpenGL technically disallows * most drawing while non-persistent mappings are active, we may still use * the GPU for blits or other operations, causing batches to happen at * inconvenient times. * * If RAW is set, we expect the caller to be able to handle a WC buffer * more efficiently than the involuntary clflushes. */ if (flags & (MAP_PERSISTENT | MAP_COHERENT | MAP_ASYNC | MAP_RAW)) return false; return !(flags & MAP_WRITE); } void * crocus_bo_map(struct pipe_debug_callback *dbg, struct crocus_bo *bo, unsigned flags) { if (bo->tiling_mode != I915_TILING_NONE && !(flags & MAP_RAW)) return crocus_bo_map_gtt(dbg, bo, flags); void *map; if (can_map_cpu(bo, flags)) map = crocus_bo_map_cpu(dbg, bo, flags); else map = crocus_bo_map_wc(dbg, bo, flags); /* Allow the attempt to fail by falling back to the GTT where necessary. * * Not every buffer can be mmaped directly using the CPU (or WC), for * example buffers that wrap stolen memory or are imported from other * devices. For those, we have little choice but to use a GTT mmapping. * However, if we use a slow GTT mmapping for reads where we expected fast * access, that order of magnitude difference in throughput will be clearly * expressed by angry users. * * We skip MAP_RAW because we want to avoid map_gtt's fence detiling. */ if (!map && !(flags & MAP_RAW)) { perf_debug(dbg, "Fallback GTT mapping for %s with access flags %x\n", bo->name, flags); map = crocus_bo_map_gtt(dbg, bo, flags); } return map; } /** Waits for all GPU rendering with the object to have completed. */ void crocus_bo_wait_rendering(struct crocus_bo *bo) { /* We require a kernel recent enough for WAIT_IOCTL support. * See intel_init_bufmgr() */ crocus_bo_wait(bo, -1); } /** * Waits on a BO for the given amount of time. * * @bo: buffer object to wait for * @timeout_ns: amount of time to wait in nanoseconds. * If value is less than 0, an infinite wait will occur. * * Returns 0 if the wait was successful ie. the last batch referencing the * object has completed within the allotted time. Otherwise some negative return * value describes the error. Of particular interest is -ETIME when the wait has * failed to yield the desired result. * * Similar to crocus_bo_wait_rendering except a timeout parameter allows * the operation to give up after a certain amount of time. Another subtle * difference is the internal locking semantics are different (this variant does * not hold the lock for the duration of the wait). This makes the wait subject * to a larger userspace race window. * * The implementation shall wait until the object is no longer actively * referenced within a batch buffer at the time of the call. The wait will * not guarantee that the buffer is re-issued via another thread, or an flinked * handle. Userspace must make sure this race does not occur if such precision * is important. * * Note that some kernels have broken the inifite wait for negative values * promise, upgrade to latest stable kernels if this is the case. */ int crocus_bo_wait(struct crocus_bo *bo, int64_t timeout_ns) { struct crocus_bufmgr *bufmgr = bo->bufmgr; /* If we know it's idle, don't bother with the kernel round trip */ if (bo->idle && !bo->external) return 0; struct drm_i915_gem_wait wait = { .bo_handle = bo->gem_handle, .timeout_ns = timeout_ns, }; int ret = intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_WAIT, &wait); if (ret != 0) return -errno; bo->idle = true; return ret; } static void crocus_bufmgr_destroy(struct crocus_bufmgr *bufmgr) { simple_mtx_destroy(&bufmgr->lock); /* Free any cached buffer objects we were going to reuse */ for (int i = 0; i < bufmgr->num_buckets; i++) { struct bo_cache_bucket *bucket = &bufmgr->cache_bucket[i]; list_for_each_entry_safe(struct crocus_bo, bo, &bucket->head, head) { list_del(&bo->head); bo_free(bo); } } /* Close any buffer objects on the dead list. */ list_for_each_entry_safe(struct crocus_bo, bo, &bufmgr->zombie_list, head) { list_del(&bo->head); bo_close(bo); } _mesa_hash_table_destroy(bufmgr->name_table, NULL); _mesa_hash_table_destroy(bufmgr->handle_table, NULL); close(bufmgr->fd); free(bufmgr); } static int bo_set_tiling_internal(struct crocus_bo *bo, uint32_t tiling_mode, uint32_t stride) { struct crocus_bufmgr *bufmgr = bo->bufmgr; struct drm_i915_gem_set_tiling set_tiling; int ret; if (bo->global_name == 0 && tiling_mode == bo->tiling_mode && stride == bo->stride) return 0; memset(&set_tiling, 0, sizeof(set_tiling)); do { /* set_tiling is slightly broken and overwrites the * input on the error path, so we have to open code * drm_ioctl. */ set_tiling.handle = bo->gem_handle; set_tiling.tiling_mode = tiling_mode; set_tiling.stride = stride; ret = ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_SET_TILING, &set_tiling); } while (ret == -1 && (errno == EINTR || errno == EAGAIN)); if (ret == -1) return -errno; bo->tiling_mode = set_tiling.tiling_mode; bo->swizzle_mode = set_tiling.swizzle_mode; bo->stride = set_tiling.stride; return 0; } int crocus_bo_get_tiling(struct crocus_bo *bo, uint32_t *tiling_mode, uint32_t *swizzle_mode) { *tiling_mode = bo->tiling_mode; *swizzle_mode = bo->swizzle_mode; return 0; } struct crocus_bo * crocus_bo_import_dmabuf(struct crocus_bufmgr *bufmgr, int prime_fd, uint64_t modifier) { uint32_t handle; struct crocus_bo *bo; simple_mtx_lock(&bufmgr->lock); int ret = drmPrimeFDToHandle(bufmgr->fd, prime_fd, &handle); if (ret) { DBG("import_dmabuf: failed to obtain handle from fd: %s\n", strerror(errno)); simple_mtx_unlock(&bufmgr->lock); return NULL; } /* * See if the kernel has already returned this buffer to us. Just as * for named buffers, we must not create two bo's pointing at the same * kernel object */ bo = find_and_ref_external_bo(bufmgr->handle_table, handle); if (bo) goto out; bo = bo_calloc(); if (!bo) goto out; p_atomic_set(&bo->refcount, 1); /* Determine size of bo. The fd-to-handle ioctl really should * return the size, but it doesn't. If we have kernel 3.12 or * later, we can lseek on the prime fd to get the size. Older * kernels will just fail, in which case we fall back to the * provided (estimated or guess size). */ ret = lseek(prime_fd, 0, SEEK_END); if (ret != -1) bo->size = ret; bo->bufmgr = bufmgr; bo->name = "prime"; bo->reusable = false; bo->external = true; bo->kflags = 0; bo->gem_handle = handle; _mesa_hash_table_insert(bufmgr->handle_table, &bo->gem_handle, bo); const struct isl_drm_modifier_info *mod_info = isl_drm_modifier_get_info(modifier); if (mod_info) { bo->tiling_mode = isl_tiling_to_i915_tiling(mod_info->tiling); } else if (bufmgr->has_tiling_uapi) { struct drm_i915_gem_get_tiling get_tiling = { .handle = bo->gem_handle }; if (intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_GET_TILING, &get_tiling)) goto err; bo->tiling_mode = get_tiling.tiling_mode; } else { bo->tiling_mode = I915_TILING_NONE; } out: simple_mtx_unlock(&bufmgr->lock); return bo; err: bo_free(bo); simple_mtx_unlock(&bufmgr->lock); return NULL; } struct crocus_bo * crocus_bo_import_dmabuf_no_mods(struct crocus_bufmgr *bufmgr, int prime_fd) { uint32_t handle; struct crocus_bo *bo; simple_mtx_lock(&bufmgr->lock); int ret = drmPrimeFDToHandle(bufmgr->fd, prime_fd, &handle); if (ret) { DBG("import_dmabuf: failed to obtain handle from fd: %s\n", strerror(errno)); simple_mtx_unlock(&bufmgr->lock); return NULL; } /* * See if the kernel has already returned this buffer to us. Just as * for named buffers, we must not create two bo's pointing at the same * kernel object */ bo = find_and_ref_external_bo(bufmgr->handle_table, handle); if (bo) goto out; bo = bo_calloc(); if (!bo) goto out; p_atomic_set(&bo->refcount, 1); /* Determine size of bo. The fd-to-handle ioctl really should * return the size, but it doesn't. If we have kernel 3.12 or * later, we can lseek on the prime fd to get the size. Older * kernels will just fail, in which case we fall back to the * provided (estimated or guess size). */ ret = lseek(prime_fd, 0, SEEK_END); if (ret != -1) bo->size = ret; bo->bufmgr = bufmgr; bo->name = "prime"; bo->reusable = false; bo->external = true; bo->kflags = 0; bo->gem_handle = handle; _mesa_hash_table_insert(bufmgr->handle_table, &bo->gem_handle, bo); out: simple_mtx_unlock(&bufmgr->lock); return bo; } static void crocus_bo_make_external_locked(struct crocus_bo *bo) { if (!bo->external) { _mesa_hash_table_insert(bo->bufmgr->handle_table, &bo->gem_handle, bo); bo->external = true; bo->reusable = false; } } static void crocus_bo_make_external(struct crocus_bo *bo) { struct crocus_bufmgr *bufmgr = bo->bufmgr; if (bo->external) { assert(!bo->reusable); return; } simple_mtx_lock(&bufmgr->lock); crocus_bo_make_external_locked(bo); simple_mtx_unlock(&bufmgr->lock); } int crocus_bo_export_dmabuf(struct crocus_bo *bo, int *prime_fd) { struct crocus_bufmgr *bufmgr = bo->bufmgr; crocus_bo_make_external(bo); if (drmPrimeHandleToFD(bufmgr->fd, bo->gem_handle, DRM_CLOEXEC, prime_fd) != 0) return -errno; return 0; } uint32_t crocus_bo_export_gem_handle(struct crocus_bo *bo) { crocus_bo_make_external(bo); return bo->gem_handle; } int crocus_bo_flink(struct crocus_bo *bo, uint32_t *name) { struct crocus_bufmgr *bufmgr = bo->bufmgr; if (!bo->global_name) { struct drm_gem_flink flink = { .handle = bo->gem_handle }; if (intel_ioctl(bufmgr->fd, DRM_IOCTL_GEM_FLINK, &flink)) return -errno; simple_mtx_lock(&bufmgr->lock); if (!bo->global_name) { crocus_bo_make_external_locked(bo); bo->global_name = flink.name; _mesa_hash_table_insert(bufmgr->name_table, &bo->global_name, bo); } simple_mtx_unlock(&bufmgr->lock); } *name = bo->global_name; return 0; } int crocus_bo_export_gem_handle_for_device(struct crocus_bo *bo, int drm_fd, uint32_t *out_handle) { /* Only add the new GEM handle to the list of export if it belongs to a * different GEM device. Otherwise we might close the same buffer multiple * times. */ struct crocus_bufmgr *bufmgr = bo->bufmgr; int ret = os_same_file_description(drm_fd, bufmgr->fd); WARN_ONCE(ret < 0, "Kernel has no file descriptor comparison support: %s\n", strerror(errno)); if (ret == 0) { *out_handle = crocus_bo_export_gem_handle(bo); return 0; } struct bo_export *export = calloc(1, sizeof(*export)); if (!export) return -ENOMEM; export->drm_fd = drm_fd; int dmabuf_fd = -1; int err = crocus_bo_export_dmabuf(bo, &dmabuf_fd); if (err) { free(export); return err; } simple_mtx_lock(&bufmgr->lock); err = drmPrimeFDToHandle(drm_fd, dmabuf_fd, &export->gem_handle); close(dmabuf_fd); if (err) { simple_mtx_unlock(&bufmgr->lock); free(export); return err; } bool found = false; list_for_each_entry(struct bo_export, iter, &bo->exports, link) { if (iter->drm_fd != drm_fd) continue; /* Here we assume that for a given DRM fd, we'll always get back the * same GEM handle for a given buffer. */ assert(iter->gem_handle == export->gem_handle); free(export); export = iter; found = true; break; } if (!found) list_addtail(&export->link, &bo->exports); simple_mtx_unlock(&bufmgr->lock); *out_handle = export->gem_handle; return 0; } static void add_bucket(struct crocus_bufmgr *bufmgr, int size) { unsigned int i = bufmgr->num_buckets; assert(i < ARRAY_SIZE(bufmgr->cache_bucket)); list_inithead(&bufmgr->cache_bucket[i].head); bufmgr->cache_bucket[i].size = size; bufmgr->num_buckets++; assert(bucket_for_size(bufmgr, size) == &bufmgr->cache_bucket[i]); assert(bucket_for_size(bufmgr, size - 2048) == &bufmgr->cache_bucket[i]); assert(bucket_for_size(bufmgr, size + 1) != &bufmgr->cache_bucket[i]); } static void init_cache_buckets(struct crocus_bufmgr *bufmgr) { uint64_t size, cache_max_size = 64 * 1024 * 1024; /* OK, so power of two buckets was too wasteful of memory. * Give 3 other sizes between each power of two, to hopefully * cover things accurately enough. (The alternative is * probably to just go for exact matching of sizes, and assume * that for things like composited window resize the tiled * width/height alignment and rounding of sizes to pages will * get us useful cache hit rates anyway) */ add_bucket(bufmgr, PAGE_SIZE); add_bucket(bufmgr, PAGE_SIZE * 2); add_bucket(bufmgr, PAGE_SIZE * 3); /* Initialize the linked lists for BO reuse cache. */ for (size = 4 * PAGE_SIZE; size <= cache_max_size; size *= 2) { add_bucket(bufmgr, size); add_bucket(bufmgr, size + size * 1 / 4); add_bucket(bufmgr, size + size * 2 / 4); add_bucket(bufmgr, size + size * 3 / 4); } } uint32_t crocus_create_hw_context(struct crocus_bufmgr *bufmgr) { struct drm_i915_gem_context_create create = { }; int ret = intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_CONTEXT_CREATE, &create); if (ret != 0) { DBG("DRM_IOCTL_I915_GEM_CONTEXT_CREATE failed: %s\n", strerror(errno)); return 0; } /* Upon declaring a GPU hang, the kernel will zap the guilty context * back to the default logical HW state and attempt to continue on to * our next submitted batchbuffer. However, our render batches assume * the previous GPU state is preserved, and only emit commands needed * to incrementally change that state. In particular, we inherit the * STATE_BASE_ADDRESS and PIPELINE_SELECT settings, which are critical. * With default base addresses, our next batches will almost certainly * cause more GPU hangs, leading to repeated hangs until we're banned * or the machine is dead. * * Here we tell the kernel not to attempt to recover our context but * immediately (on the next batchbuffer submission) report that the * context is lost, and we will do the recovery ourselves. Ideally, * we'll have two lost batches instead of a continual stream of hangs. */ struct drm_i915_gem_context_param p = { .ctx_id = create.ctx_id, .param = I915_CONTEXT_PARAM_RECOVERABLE, .value = false, }; drmIoctl(bufmgr->fd, DRM_IOCTL_I915_GEM_CONTEXT_SETPARAM, &p); return create.ctx_id; } static int crocus_hw_context_get_priority(struct crocus_bufmgr *bufmgr, uint32_t ctx_id) { struct drm_i915_gem_context_param p = { .ctx_id = ctx_id, .param = I915_CONTEXT_PARAM_PRIORITY, }; drmIoctl(bufmgr->fd, DRM_IOCTL_I915_GEM_CONTEXT_GETPARAM, &p); return p.value; /* on error, return 0 i.e. default priority */ } int crocus_hw_context_set_priority(struct crocus_bufmgr *bufmgr, uint32_t ctx_id, int priority) { struct drm_i915_gem_context_param p = { .ctx_id = ctx_id, .param = I915_CONTEXT_PARAM_PRIORITY, .value = priority, }; int err; err = 0; if (intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_CONTEXT_SETPARAM, &p)) err = -errno; return err; } uint32_t crocus_clone_hw_context(struct crocus_bufmgr *bufmgr, uint32_t ctx_id) { uint32_t new_ctx = crocus_create_hw_context(bufmgr); if (new_ctx) { int priority = crocus_hw_context_get_priority(bufmgr, ctx_id); crocus_hw_context_set_priority(bufmgr, new_ctx, priority); } return new_ctx; } void crocus_destroy_hw_context(struct crocus_bufmgr *bufmgr, uint32_t ctx_id) { struct drm_i915_gem_context_destroy d = { .ctx_id = ctx_id }; if (ctx_id != 0 && intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_GEM_CONTEXT_DESTROY, &d) != 0) { fprintf(stderr, "DRM_IOCTL_I915_GEM_CONTEXT_DESTROY failed: %s\n", strerror(errno)); } } int crocus_reg_read(struct crocus_bufmgr *bufmgr, uint32_t offset, uint64_t *result) { struct drm_i915_reg_read reg_read = { .offset = offset }; int ret = intel_ioctl(bufmgr->fd, DRM_IOCTL_I915_REG_READ, ®_read); *result = reg_read.val; return ret; } static int gem_param(int fd, int name) { int v = -1; /* No param uses (yet) the sign bit, reserve it for errors */ struct drm_i915_getparam gp = { .param = name, .value = &v }; if (intel_ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp)) return -1; return v; } /** * Initializes the GEM buffer manager, which uses the kernel to allocate, map, * and manage map buffer objections. * * \param fd File descriptor of the opened DRM device. */ static struct crocus_bufmgr * crocus_bufmgr_create(struct intel_device_info *devinfo, int fd, bool bo_reuse) { struct crocus_bufmgr *bufmgr = calloc(1, sizeof(*bufmgr)); if (bufmgr == NULL) return NULL; /* Handles to buffer objects belong to the device fd and are not * reference counted by the kernel. If the same fd is used by * multiple parties (threads sharing the same screen bufmgr, or * even worse the same device fd passed to multiple libraries) * ownership of those handles is shared by those independent parties. * * Don't do this! Ensure that each library/bufmgr has its own device * fd so that its namespace does not clash with another. */ bufmgr->fd = os_dupfd_cloexec(fd); p_atomic_set(&bufmgr->refcount, 1); simple_mtx_init(&bufmgr->lock, mtx_plain); list_inithead(&bufmgr->zombie_list); bufmgr->has_llc = devinfo->has_llc; bufmgr->has_tiling_uapi = devinfo->has_tiling_uapi; bufmgr->bo_reuse = bo_reuse; bufmgr->has_mmap_offset = gem_param(fd, I915_PARAM_MMAP_GTT_VERSION) >= 4; init_cache_buckets(bufmgr); bufmgr->name_table = _mesa_hash_table_create(NULL, key_hash_uint, key_uint_equal); bufmgr->handle_table = _mesa_hash_table_create(NULL, key_hash_uint, key_uint_equal); return bufmgr; } static struct crocus_bufmgr * crocus_bufmgr_ref(struct crocus_bufmgr *bufmgr) { p_atomic_inc(&bufmgr->refcount); return bufmgr; } void crocus_bufmgr_unref(struct crocus_bufmgr *bufmgr) { simple_mtx_lock(&global_bufmgr_list_mutex); if (p_atomic_dec_zero(&bufmgr->refcount)) { list_del(&bufmgr->link); crocus_bufmgr_destroy(bufmgr); } simple_mtx_unlock(&global_bufmgr_list_mutex); } /** * Gets an already existing GEM buffer manager or create a new one. * * \param fd File descriptor of the opened DRM device. */ struct crocus_bufmgr * crocus_bufmgr_get_for_fd(struct intel_device_info *devinfo, int fd, bool bo_reuse) { struct stat st; if (fstat(fd, &st)) return NULL; struct crocus_bufmgr *bufmgr = NULL; simple_mtx_lock(&global_bufmgr_list_mutex); list_for_each_entry(struct crocus_bufmgr, iter_bufmgr, &global_bufmgr_list, link) { struct stat iter_st; if (fstat(iter_bufmgr->fd, &iter_st)) continue; if (st.st_rdev == iter_st.st_rdev) { assert(iter_bufmgr->bo_reuse == bo_reuse); bufmgr = crocus_bufmgr_ref(iter_bufmgr); goto unlock; } } bufmgr = crocus_bufmgr_create(devinfo, fd, bo_reuse); if (bufmgr) list_addtail(&bufmgr->link, &global_bufmgr_list); unlock: simple_mtx_unlock(&global_bufmgr_list_mutex); return bufmgr; } int crocus_bufmgr_get_fd(struct crocus_bufmgr *bufmgr) { return bufmgr->fd; }