/*
* Copyright © 2015 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 (including the next
* paragraph) 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.
*/
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
#include <assert.h>
#include <linux/memfd.h>
#include <sys/mman.h>
#include "anv_private.h"
#include "util/hash_table.h"
#include "util/simple_mtx.h"
#ifdef HAVE_VALGRIND
#define VG_NOACCESS_READ(__ptr) ({ \
VALGRIND_MAKE_MEM_DEFINED((__ptr), sizeof(*(__ptr))); \
__typeof(*(__ptr)) __val = *(__ptr); \
VALGRIND_MAKE_MEM_NOACCESS((__ptr), sizeof(*(__ptr)));\
__val; \
})
#define VG_NOACCESS_WRITE(__ptr, __val) ({ \
VALGRIND_MAKE_MEM_UNDEFINED((__ptr), sizeof(*(__ptr))); \
*(__ptr) = (__val); \
VALGRIND_MAKE_MEM_NOACCESS((__ptr), sizeof(*(__ptr))); \
})
#else
#define VG_NOACCESS_READ(__ptr) (*(__ptr))
#define VG_NOACCESS_WRITE(__ptr, __val) (*(__ptr) = (__val))
#endif
/* Design goals:
*
* - Lock free (except when resizing underlying bos)
*
* - Constant time allocation with typically only one atomic
*
* - Multiple allocation sizes without fragmentation
*
* - Can grow while keeping addresses and offset of contents stable
*
* - All allocations within one bo so we can point one of the
* STATE_BASE_ADDRESS pointers at it.
*
* The overall design is a two-level allocator: top level is a fixed size, big
* block (8k) allocator, which operates out of a bo. Allocation is done by
* either pulling a block from the free list or growing the used range of the
* bo. Growing the range may run out of space in the bo which we then need to
* grow. Growing the bo is tricky in a multi-threaded, lockless environment:
* we need to keep all pointers and contents in the old map valid. GEM bos in
* general can't grow, but we use a trick: we create a memfd and use ftruncate
* to grow it as necessary. We mmap the new size and then create a gem bo for
* it using the new gem userptr ioctl. Without heavy-handed locking around
* our allocation fast-path, there isn't really a way to munmap the old mmap,
* so we just keep it around until garbage collection time. While the block
* allocator is lockless for normal operations, we block other threads trying
* to allocate while we're growing the map. It sholdn't happen often, and
* growing is fast anyway.
*
* At the next level we can use various sub-allocators. The state pool is a
* pool of smaller, fixed size objects, which operates much like the block
* pool. It uses a free list for freeing objects, but when it runs out of
* space it just allocates a new block from the block pool. This allocator is
* intended for longer lived state objects such as SURFACE_STATE and most
* other persistent state objects in the API. We may need to track more info
* with these object and a pointer back to the CPU object (eg VkImage). In
* those cases we just allocate a slightly bigger object and put the extra
* state after the GPU state object.
*
* The state stream allocator works similar to how the i965 DRI driver streams
* all its state. Even with Vulkan, we need to emit transient state (whether
* surface state base or dynamic state base), and for that we can just get a
* block and fill it up. These cases are local to a command buffer and the
* sub-allocator need not be thread safe. The streaming allocator gets a new
* block when it runs out of space and chains them together so they can be
* easily freed.
*/
/* Allocations are always at least 64 byte aligned, so 1 is an invalid value.
* We use it to indicate the free list is empty. */
#define EMPTY 1
struct anv_mmap_cleanup {
void *map;
size_t size;
uint32_t gem_handle;
};
#define ANV_MMAP_CLEANUP_INIT ((struct anv_mmap_cleanup){0})
#ifndef HAVE_MEMFD_CREATE
static inline int
memfd_create(const char *name, unsigned int flags)
{
return syscall(SYS_memfd_create, name, flags);
}
#endif
static inline uint32_t
ilog2_round_up(uint32_t value)
{
assert(value != 0);
return 32 - __builtin_clz(value - 1);
}
static inline uint32_t
round_to_power_of_two(uint32_t value)
{
return 1 << ilog2_round_up(value);
}
static bool
anv_free_list_pop(union anv_free_list *list, void **map, int32_t *offset)
{
union anv_free_list current, new, old;
current.u64 = list->u64;
while (current.offset != EMPTY) {
/* We have to add a memory barrier here so that the list head (and
* offset) gets read before we read the map pointer. This way we
* know that the map pointer is valid for the given offset at the
* point where we read it.
*/
__sync_synchronize();
int32_t *next_ptr = *map + current.offset;
new.offset = VG_NOACCESS_READ(next_ptr);
new.count = current.count + 1;
old.u64 = __sync_val_compare_and_swap(&list->u64, current.u64, new.u64);
if (old.u64 == current.u64) {
*offset = current.offset;
return true;
}
current = old;
}
return false;
}
static void
anv_free_list_push(union anv_free_list *list, void *map, int32_t offset,
uint32_t size, uint32_t count)
{
union anv_free_list current, old, new;
int32_t *next_ptr = map + offset;
/* If we're returning more than one chunk, we need to build a chain to add
* to the list. Fortunately, we can do this without any atomics since we
* own everything in the chain right now. `offset` is left pointing to the
* head of our chain list while `next_ptr` points to the tail.
*/
for (uint32_t i = 1; i < count; i++) {
VG_NOACCESS_WRITE(next_ptr, offset + i * size);
next_ptr = map + offset + i * size;
}
old = *list;
do {
current = old;
VG_NOACCESS_WRITE(next_ptr, current.offset);
new.offset = offset;
new.count = current.count + 1;
old.u64 = __sync_val_compare_and_swap(&list->u64, current.u64, new.u64);
} while (old.u64 != current.u64);
}
/* All pointers in the ptr_free_list are assumed to be page-aligned. This
* means that the bottom 12 bits should all be zero.
*/
#define PFL_COUNT(x) ((uintptr_t)(x) & 0xfff)
#define PFL_PTR(x) ((void *)((uintptr_t)(x) & ~(uintptr_t)0xfff))
#define PFL_PACK(ptr, count) ({ \
(void *)(((uintptr_t)(ptr) & ~(uintptr_t)0xfff) | ((count) & 0xfff)); \
})
static bool
anv_ptr_free_list_pop(void **list, void **elem)
{
void *current = *list;
while (PFL_PTR(current) != NULL) {
void **next_ptr = PFL_PTR(current);
void *new_ptr = VG_NOACCESS_READ(next_ptr);
unsigned new_count = PFL_COUNT(current) + 1;
void *new = PFL_PACK(new_ptr, new_count);
void *old = __sync_val_compare_and_swap(list, current, new);
if (old == current) {
*elem = PFL_PTR(current);
return true;
}
current = old;
}
return false;
}
static void
anv_ptr_free_list_push(void **list, void *elem)
{
void *old, *current;
void **next_ptr = elem;
/* The pointer-based free list requires that the pointer be
* page-aligned. This is because we use the bottom 12 bits of the
* pointer to store a counter to solve the ABA concurrency problem.
*/
assert(((uintptr_t)elem & 0xfff) == 0);
old = *list;
do {
current = old;
VG_NOACCESS_WRITE(next_ptr, PFL_PTR(current));
unsigned new_count = PFL_COUNT(current) + 1;
void *new = PFL_PACK(elem, new_count);
old = __sync_val_compare_and_swap(list, current, new);
} while (old != current);
}
static VkResult
anv_block_pool_expand_range(struct anv_block_pool *pool,
uint32_t center_bo_offset, uint32_t size);
VkResult
anv_block_pool_init(struct anv_block_pool *pool,
struct anv_device *device,
uint64_t start_address,
uint32_t initial_size,
uint64_t bo_flags)
{
VkResult result;
pool->device = device;
pool->bo_flags = bo_flags;
pool->start_address = gen_canonical_address(start_address);
anv_bo_init(&pool->bo, 0, 0);
pool->fd = memfd_create("block pool", MFD_CLOEXEC);
if (pool->fd == -1)
return vk_error(VK_ERROR_INITIALIZATION_FAILED);
/* Just make it 2GB up-front. The Linux kernel won't actually back it
* with pages until we either map and fault on one of them or we use
* userptr and send a chunk of it off to the GPU.
*/
if (ftruncate(pool->fd, BLOCK_POOL_MEMFD_SIZE) == -1) {
result = vk_error(VK_ERROR_INITIALIZATION_FAILED);
goto fail_fd;
}
if (!u_vector_init(&pool->mmap_cleanups,
round_to_power_of_two(sizeof(struct anv_mmap_cleanup)),
128)) {
result = vk_error(VK_ERROR_INITIALIZATION_FAILED);
goto fail_fd;
}
pool->state.next = 0;
pool->state.end = 0;
pool->back_state.next = 0;
pool->back_state.end = 0;
result = anv_block_pool_expand_range(pool, 0, initial_size);
if (result != VK_SUCCESS)
goto fail_mmap_cleanups;
return VK_SUCCESS;
fail_mmap_cleanups:
u_vector_finish(&pool->mmap_cleanups);
fail_fd:
close(pool->fd);
return result;
}
void
anv_block_pool_finish(struct anv_block_pool *pool)
{
struct anv_mmap_cleanup *cleanup;
u_vector_foreach(cleanup, &pool->mmap_cleanups) {
if (cleanup->map)
munmap(cleanup->map, cleanup->size);
if (cleanup->gem_handle)
anv_gem_close(pool->device, cleanup->gem_handle);
}
u_vector_finish(&pool->mmap_cleanups);
close(pool->fd);
}
#define PAGE_SIZE 4096
static VkResult
anv_block_pool_expand_range(struct anv_block_pool *pool,
uint32_t center_bo_offset, uint32_t size)
{
void *map;
uint32_t gem_handle;
struct anv_mmap_cleanup *cleanup;
/* Assert that we only ever grow the pool */
assert(center_bo_offset >= pool->back_state.end);
assert(size - center_bo_offset >= pool->state.end);
/* Assert that we don't go outside the bounds of the memfd */
assert(center_bo_offset <= BLOCK_POOL_MEMFD_CENTER);
assert(size - center_bo_offset <=
BLOCK_POOL_MEMFD_SIZE - BLOCK_POOL_MEMFD_CENTER);
cleanup = u_vector_add(&pool->mmap_cleanups);
if (!cleanup)
return vk_error(VK_ERROR_OUT_OF_HOST_MEMORY);
*cleanup = ANV_MMAP_CLEANUP_INIT;
/* Just leak the old map until we destroy the pool. We can't munmap it
* without races or imposing locking on the block allocate fast path. On
* the whole the leaked maps adds up to less than the size of the
* current map. MAP_POPULATE seems like the right thing to do, but we
* should try to get some numbers.
*/
map = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_POPULATE, pool->fd,
BLOCK_POOL_MEMFD_CENTER - center_bo_offset);
if (map == MAP_FAILED)
return vk_errorf(pool->device->instance, pool->device,
VK_ERROR_MEMORY_MAP_FAILED, "mmap failed: %m");
gem_handle = anv_gem_userptr(pool->device, map, size);
if (gem_handle == 0) {
munmap(map, size);
return vk_errorf(pool->device->instance, pool->device,
VK_ERROR_TOO_MANY_OBJECTS, "userptr failed: %m");
}
cleanup->map = map;
cleanup->size = size;
cleanup->gem_handle = gem_handle;
#if 0
/* Regular objects are created I915_CACHING_CACHED on LLC platforms and
* I915_CACHING_NONE on non-LLC platforms. However, userptr objects are
* always created as I915_CACHING_CACHED, which on non-LLC means
* snooped. That can be useful but comes with a bit of overheard. Since
* we're eplicitly clflushing and don't want the overhead we need to turn
* it off. */
if (!pool->device->info.has_llc) {
anv_gem_set_caching(pool->device, gem_handle, I915_CACHING_NONE);
anv_gem_set_domain(pool->device, gem_handle,
I915_GEM_DOMAIN_GTT, I915_GEM_DOMAIN_GTT);
}
#endif
/* Now that we successfull allocated everything, we can write the new
* values back into pool. */
pool->map = map + center_bo_offset;
pool->center_bo_offset = center_bo_offset;
/* For block pool BOs we have to be a bit careful about where we place them
* in the GTT. There are two documented workarounds for state base address
* placement : Wa32bitGeneralStateOffset and Wa32bitInstructionBaseOffset
* which state that those two base addresses do not support 48-bit
* addresses and need to be placed in the bottom 32-bit range.
* Unfortunately, this is not quite accurate.
*
* The real problem is that we always set the size of our state pools in
* STATE_BASE_ADDRESS to 0xfffff (the maximum) even though the BO is most
* likely significantly smaller. We do this because we do not no at the
* time we emit STATE_BASE_ADDRESS whether or not we will need to expand
* the pool during command buffer building so we don't actually have a
* valid final size. If the address + size, as seen by STATE_BASE_ADDRESS
* overflows 48 bits, the GPU appears to treat all accesses to the buffer
* as being out of bounds and returns zero. For dynamic state, this
* usually just leads to rendering corruptions, but shaders that are all
* zero hang the GPU immediately.
*
* The easiest solution to do is exactly what the bogus workarounds say to
* do: restrict these buffers to 32-bit addresses. We could also pin the
* BO to some particular location of our choosing, but that's significantly
* more work than just not setting a flag. So, we explicitly DO NOT set
* the EXEC_OBJECT_SUPPORTS_48B_ADDRESS flag and the kernel does all of the
* hard work for us.
*/
anv_bo_init(&pool->bo, gem_handle, size);
if (pool->bo_flags & EXEC_OBJECT_PINNED) {
pool->bo.offset = pool->start_address + BLOCK_POOL_MEMFD_CENTER -
center_bo_offset;
}
pool->bo.flags = pool->bo_flags;
pool->bo.map = map;
return VK_SUCCESS;
}
/** Grows and re-centers the block pool.
*
* We grow the block pool in one or both directions in such a way that the
* following conditions are met:
*
* 1) The size of the entire pool is always a power of two.
*
* 2) The pool only grows on both ends. Neither end can get
* shortened.
*
* 3) At the end of the allocation, we have about twice as much space
* allocated for each end as we have used. This way the pool doesn't
* grow too far in one direction or the other.
*
* 4) If the _alloc_back() has never been called, then the back portion of
* the pool retains a size of zero. (This makes it easier for users of
* the block pool that only want a one-sided pool.)
*
* 5) We have enough space allocated for at least one more block in
* whichever side `state` points to.
*
* 6) The center of the pool is always aligned to both the block_size of
* the pool and a 4K CPU page.
*/
static uint32_t
anv_block_pool_grow(struct anv_block_pool *pool, struct anv_block_state *state)
{
VkResult result = VK_SUCCESS;
pthread_mutex_lock(&pool->device->mutex);
assert(state == &pool->state || state == &pool->back_state);
/* Gather a little usage information on the pool. Since we may have
* threadsd waiting in queue to get some storage while we resize, it's
* actually possible that total_used will be larger than old_size. In
* particular, block_pool_alloc() increments state->next prior to
* calling block_pool_grow, so this ensures that we get enough space for
* which ever side tries to grow the pool.
*
* We align to a page size because it makes it easier to do our
* calculations later in such a way that we state page-aigned.
*/
uint32_t back_used = align_u32(pool->back_state.next, PAGE_SIZE);
uint32_t front_used = align_u32(pool->state.next, PAGE_SIZE);
uint32_t total_used = front_used + back_used;
assert(state == &pool->state || back_used > 0);
uint32_t old_size = pool->bo.size;
/* The block pool is always initialized to a nonzero size and this function
* is always called after initialization.
*/
assert(old_size > 0);
/* The back_used and front_used may actually be smaller than the actual
* requirement because they are based on the next pointers which are
* updated prior to calling this function.
*/
uint32_t back_required = MAX2(back_used, pool->center_bo_offset);
uint32_t front_required = MAX2(front_used, old_size - pool->center_bo_offset);
if (back_used * 2 <= back_required && front_used * 2 <= front_required) {
/* If we're in this case then this isn't the firsta allocation and we
* already have enough space on both sides to hold double what we
* have allocated. There's nothing for us to do.
*/
goto done;
}
uint32_t size = old_size * 2;
while (size < back_required + front_required)
size *= 2;
assert(size > pool->bo.size);
/* We compute a new center_bo_offset such that, when we double the size
* of the pool, we maintain the ratio of how much is used by each side.
* This way things should remain more-or-less balanced.
*/
uint32_t center_bo_offset;
if (back_used == 0) {
/* If we're in this case then we have never called alloc_back(). In
* this case, we want keep the offset at 0 to make things as simple
* as possible for users that don't care about back allocations.
*/
center_bo_offset = 0;
} else {
/* Try to "center" the allocation based on how much is currently in
* use on each side of the center line.
*/
center_bo_offset = ((uint64_t)size * back_used) / total_used;
/* Align down to a multiple of the page size */
center_bo_offset &= ~(PAGE_SIZE - 1);
assert(center_bo_offset >= back_used);
/* Make sure we don't shrink the back end of the pool */
if (center_bo_offset < back_required)
center_bo_offset = back_required;
/* Make sure that we don't shrink the front end of the pool */
if (size - center_bo_offset < front_required)
center_bo_offset = size - front_required;
}
assert(center_bo_offset % PAGE_SIZE == 0);
result = anv_block_pool_expand_range(pool, center_bo_offset, size);
pool->bo.flags = pool->bo_flags;
done:
pthread_mutex_unlock(&pool->device->mutex);
if (result == VK_SUCCESS) {
/* Return the appropriate new size. This function never actually
* updates state->next. Instead, we let the caller do that because it
* needs to do so in order to maintain its concurrency model.
*/
if (state == &pool->state) {
return pool->bo.size - pool->center_bo_offset;
} else {
assert(pool->center_bo_offset > 0);
return pool->center_bo_offset;
}
} else {
return 0;
}
}
static uint32_t
anv_block_pool_alloc_new(struct anv_block_pool *pool,
struct anv_block_state *pool_state,
uint32_t block_size)
{
struct anv_block_state state, old, new;
while (1) {
state.u64 = __sync_fetch_and_add(&pool_state->u64, block_size);
if (state.next + block_size <= state.end) {
assert(pool->map);
return state.next;
} else if (state.next <= state.end) {
/* We allocated the first block outside the pool so we have to grow
* the pool. pool_state->next acts a mutex: threads who try to
* allocate now will get block indexes above the current limit and
* hit futex_wait below.
*/
new.next = state.next + block_size;
do {
new.end = anv_block_pool_grow(pool, pool_state);
} while (new.end < new.next);
old.u64 = __sync_lock_test_and_set(&pool_state->u64, new.u64);
if (old.next != state.next)
futex_wake(&pool_state->end, INT_MAX);
return state.next;
} else {
futex_wait(&pool_state->end, state.end, NULL);
continue;
}
}
}
int32_t
anv_block_pool_alloc(struct anv_block_pool *pool,
uint32_t block_size)
{
return anv_block_pool_alloc_new(pool, &pool->state, block_size);
}
/* Allocates a block out of the back of the block pool.
*
* This will allocated a block earlier than the "start" of the block pool.
* The offsets returned from this function will be negative but will still
* be correct relative to the block pool's map pointer.
*
* If you ever use anv_block_pool_alloc_back, then you will have to do
* gymnastics with the block pool's BO when doing relocations.
*/
int32_t
anv_block_pool_alloc_back(struct anv_block_pool *pool,
uint32_t block_size)
{
int32_t offset = anv_block_pool_alloc_new(pool, &pool->back_state,
block_size);
/* The offset we get out of anv_block_pool_alloc_new() is actually the
* number of bytes downwards from the middle to the end of the block.
* We need to turn it into a (negative) offset from the middle to the
* start of the block.
*/
assert(offset >= 0);
return -(offset + block_size);
}
VkResult
anv_state_pool_init(struct anv_state_pool *pool,
struct anv_device *device,
uint64_t start_address,
uint32_t block_size,
uint64_t bo_flags)
{
VkResult result = anv_block_pool_init(&pool->block_pool, device,
start_address,
block_size * 16,
bo_flags);
if (result != VK_SUCCESS)
return result;
assert(util_is_power_of_two_or_zero(block_size));
pool->block_size = block_size;
pool->back_alloc_free_list = ANV_FREE_LIST_EMPTY;
for (unsigned i = 0; i < ANV_STATE_BUCKETS; i++) {
pool->buckets[i].free_list = ANV_FREE_LIST_EMPTY;
pool->buckets[i].block.next = 0;
pool->buckets[i].block.end = 0;
}
VG(VALGRIND_CREATE_MEMPOOL(pool, 0, false));
return VK_SUCCESS;
}
void
anv_state_pool_finish(struct anv_state_pool *pool)
{
VG(VALGRIND_DESTROY_MEMPOOL(pool));
anv_block_pool_finish(&pool->block_pool);
}
static uint32_t
anv_fixed_size_state_pool_alloc_new(struct anv_fixed_size_state_pool *pool,
struct anv_block_pool *block_pool,
uint32_t state_size,
uint32_t block_size)
{
struct anv_block_state block, old, new;
uint32_t offset;
/* If our state is large, we don't need any sub-allocation from a block.
* Instead, we just grab whole (potentially large) blocks.
*/
if (state_size >= block_size)
return anv_block_pool_alloc(block_pool, state_size);
restart:
block.u64 = __sync_fetch_and_add(&pool->block.u64, state_size);
if (block.next < block.end) {
return block.next;
} else if (block.next == block.end) {
offset = anv_block_pool_alloc(block_pool, block_size);
new.next = offset + state_size;
new.end = offset + block_size;
old.u64 = __sync_lock_test_and_set(&pool->block.u64, new.u64);
if (old.next != block.next)
futex_wake(&pool->block.end, INT_MAX);
return offset;
} else {
futex_wait(&pool->block.end, block.end, NULL);
goto restart;
}
}
static uint32_t
anv_state_pool_get_bucket(uint32_t size)
{
unsigned size_log2 = ilog2_round_up(size);
assert(size_log2 <= ANV_MAX_STATE_SIZE_LOG2);
if (size_log2 < ANV_MIN_STATE_SIZE_LOG2)
size_log2 = ANV_MIN_STATE_SIZE_LOG2;
return size_log2 - ANV_MIN_STATE_SIZE_LOG2;
}
static uint32_t
anv_state_pool_get_bucket_size(uint32_t bucket)
{
uint32_t size_log2 = bucket + ANV_MIN_STATE_SIZE_LOG2;
return 1 << size_log2;
}
static struct anv_state
anv_state_pool_alloc_no_vg(struct anv_state_pool *pool,
uint32_t size, uint32_t align)
{
uint32_t bucket = anv_state_pool_get_bucket(MAX2(size, align));
struct anv_state state;
state.alloc_size = anv_state_pool_get_bucket_size(bucket);
/* Try free list first. */
if (anv_free_list_pop(&pool->buckets[bucket].free_list,
&pool->block_pool.map, &state.offset)) {
assert(state.offset >= 0);
goto done;
}
/* Try to grab a chunk from some larger bucket and split it up */
for (unsigned b = bucket + 1; b < ANV_STATE_BUCKETS; b++) {
int32_t chunk_offset;
if (anv_free_list_pop(&pool->buckets[b].free_list,
&pool->block_pool.map, &chunk_offset)) {
unsigned chunk_size = anv_state_pool_get_bucket_size(b);
/* We've found a chunk that's larger than the requested state size.
* There are a couple of options as to what we do with it:
*
* 1) We could fully split the chunk into state.alloc_size sized
* pieces. However, this would mean that allocating a 16B
* state could potentially split a 2MB chunk into 512K smaller
* chunks. This would lead to unnecessary fragmentation.
*
* 2) The classic "buddy allocator" method would have us split the
* chunk in half and return one half. Then we would split the
* remaining half in half and return one half, and repeat as
* needed until we get down to the size we want. However, if
* you are allocating a bunch of the same size state (which is
* the common case), this means that every other allocation has
* to go up a level and every fourth goes up two levels, etc.
* This is not nearly as efficient as it could be if we did a
* little more work up-front.
*
* 3) Split the difference between (1) and (2) by doing a
* two-level split. If it's bigger than some fixed block_size,
* we split it into block_size sized chunks and return all but
* one of them. Then we split what remains into
* state.alloc_size sized chunks and return all but one.
*
* We choose option (3).
*/
if (chunk_size > pool->block_size &&
state.alloc_size < pool->block_size) {
assert(chunk_size % pool->block_size == 0);
/* We don't want to split giant chunks into tiny chunks. Instead,
* break anything bigger than a block into block-sized chunks and
* then break it down into bucket-sized chunks from there. Return
* all but the first block of the chunk to the block bucket.
*/
const uint32_t block_bucket =
anv_state_pool_get_bucket(pool->block_size);
anv_free_list_push(&pool->buckets[block_bucket].free_list,
pool->block_pool.map,
chunk_offset + pool->block_size,
pool->block_size,
(chunk_size / pool->block_size) - 1);
chunk_size = pool->block_size;
}
assert(chunk_size % state.alloc_size == 0);
anv_free_list_push(&pool->buckets[bucket].free_list,
pool->block_pool.map,
chunk_offset + state.alloc_size,
state.alloc_size,
(chunk_size / state.alloc_size) - 1);
state.offset = chunk_offset;
goto done;
}
}
state.offset = anv_fixed_size_state_pool_alloc_new(&pool->buckets[bucket],
&pool->block_pool,
state.alloc_size,
pool->block_size);
done:
state.map = pool->block_pool.map + state.offset;
return state;
}
struct anv_state
anv_state_pool_alloc(struct anv_state_pool *pool, uint32_t size, uint32_t align)
{
if (size == 0)
return ANV_STATE_NULL;
struct anv_state state = anv_state_pool_alloc_no_vg(pool, size, align);
VG(VALGRIND_MEMPOOL_ALLOC(pool, state.map, size));
return state;
}
struct anv_state
anv_state_pool_alloc_back(struct anv_state_pool *pool)
{
struct anv_state state;
state.alloc_size = pool->block_size;
if (anv_free_list_pop(&pool->back_alloc_free_list,
&pool->block_pool.map, &state.offset)) {
assert(state.offset < 0);
goto done;
}
state.offset = anv_block_pool_alloc_back(&pool->block_pool,
pool->block_size);
done:
state.map = pool->block_pool.map + state.offset;
VG(VALGRIND_MEMPOOL_ALLOC(pool, state.map, state.alloc_size));
return state;
}
static void
anv_state_pool_free_no_vg(struct anv_state_pool *pool, struct anv_state state)
{
assert(util_is_power_of_two_or_zero(state.alloc_size));
unsigned bucket = anv_state_pool_get_bucket(state.alloc_size);
if (state.offset < 0) {
assert(state.alloc_size == pool->block_size);
anv_free_list_push(&pool->back_alloc_free_list,
pool->block_pool.map, state.offset,
state.alloc_size, 1);
} else {
anv_free_list_push(&pool->buckets[bucket].free_list,
pool->block_pool.map, state.offset,
state.alloc_size, 1);
}
}
void
anv_state_pool_free(struct anv_state_pool *pool, struct anv_state state)
{
if (state.alloc_size == 0)
return;
VG(VALGRIND_MEMPOOL_FREE(pool, state.map));
anv_state_pool_free_no_vg(pool, state);
}
struct anv_state_stream_block {
struct anv_state block;
/* The next block */
struct anv_state_stream_block *next;
#ifdef HAVE_VALGRIND
/* A pointer to the first user-allocated thing in this block. This is
* what valgrind sees as the start of the block.
*/
void *_vg_ptr;
#endif
};
/* The state stream allocator is a one-shot, single threaded allocator for
* variable sized blocks. We use it for allocating dynamic state.
*/
void
anv_state_stream_init(struct anv_state_stream *stream,
struct anv_state_pool *state_pool,
uint32_t block_size)
{
stream->state_pool = state_pool;
stream->block_size = block_size;
stream->block = ANV_STATE_NULL;
stream->block_list = NULL;
/* Ensure that next + whatever > block_size. This way the first call to
* state_stream_alloc fetches a new block.
*/
stream->next = block_size;
VG(VALGRIND_CREATE_MEMPOOL(stream, 0, false));
}
void
anv_state_stream_finish(struct anv_state_stream *stream)
{
struct anv_state_stream_block *next = stream->block_list;
while (next != NULL) {
struct anv_state_stream_block sb = VG_NOACCESS_READ(next);
VG(VALGRIND_MEMPOOL_FREE(stream, sb._vg_ptr));
VG(VALGRIND_MAKE_MEM_UNDEFINED(next, stream->block_size));
anv_state_pool_free_no_vg(stream->state_pool, sb.block);
next = sb.next;
}
VG(VALGRIND_DESTROY_MEMPOOL(stream));
}
struct anv_state
anv_state_stream_alloc(struct anv_state_stream *stream,
uint32_t size, uint32_t alignment)
{
if (size == 0)
return ANV_STATE_NULL;
assert(alignment <= PAGE_SIZE);
uint32_t offset = align_u32(stream->next, alignment);
if (offset + size > stream->block.alloc_size) {
uint32_t block_size = stream->block_size;
if (block_size < size)
block_size = round_to_power_of_two(size);
stream->block = anv_state_pool_alloc_no_vg(stream->state_pool,
block_size, PAGE_SIZE);
struct anv_state_stream_block *sb = stream->block.map;
VG_NOACCESS_WRITE(&sb->block, stream->block);
VG_NOACCESS_WRITE(&sb->next, stream->block_list);
stream->block_list = sb;
VG(VG_NOACCESS_WRITE(&sb->_vg_ptr, NULL));
VG(VALGRIND_MAKE_MEM_NOACCESS(stream->block.map, stream->block_size));
/* Reset back to the start plus space for the header */
stream->next = sizeof(*sb);
offset = align_u32(stream->next, alignment);
assert(offset + size <= stream->block.alloc_size);
}
struct anv_state state = stream->block;
state.offset += offset;
state.alloc_size = size;
state.map += offset;
stream->next = offset + size;
#ifdef HAVE_VALGRIND
struct anv_state_stream_block *sb = stream->block_list;
void *vg_ptr = VG_NOACCESS_READ(&sb->_vg_ptr);
if (vg_ptr == NULL) {
vg_ptr = state.map;
VG_NOACCESS_WRITE(&sb->_vg_ptr, vg_ptr);
VALGRIND_MEMPOOL_ALLOC(stream, vg_ptr, size);
} else {
void *state_end = state.map + state.alloc_size;
/* This only updates the mempool. The newly allocated chunk is still
* marked as NOACCESS. */
VALGRIND_MEMPOOL_CHANGE(stream, vg_ptr, vg_ptr, state_end - vg_ptr);
/* Mark the newly allocated chunk as undefined */
VALGRIND_MAKE_MEM_UNDEFINED(state.map, state.alloc_size);
}
#endif
return state;
}
struct bo_pool_bo_link {
struct bo_pool_bo_link *next;
struct anv_bo bo;
};
void
anv_bo_pool_init(struct anv_bo_pool *pool, struct anv_device *device,
uint64_t bo_flags)
{
pool->device = device;
pool->bo_flags = bo_flags;
memset(pool->free_list, 0, sizeof(pool->free_list));
VG(VALGRIND_CREATE_MEMPOOL(pool, 0, false));
}
void
anv_bo_pool_finish(struct anv_bo_pool *pool)
{
for (unsigned i = 0; i < ARRAY_SIZE(pool->free_list); i++) {
struct bo_pool_bo_link *link = PFL_PTR(pool->free_list[i]);
while (link != NULL) {
struct bo_pool_bo_link link_copy = VG_NOACCESS_READ(link);
anv_gem_munmap(link_copy.bo.map, link_copy.bo.size);
anv_vma_free(pool->device, &link_copy.bo);
anv_gem_close(pool->device, link_copy.bo.gem_handle);
link = link_copy.next;
}
}
VG(VALGRIND_DESTROY_MEMPOOL(pool));
}
VkResult
anv_bo_pool_alloc(struct anv_bo_pool *pool, struct anv_bo *bo, uint32_t size)
{
VkResult result;
const unsigned size_log2 = size < 4096 ? 12 : ilog2_round_up(size);
const unsigned pow2_size = 1 << size_log2;
const unsigned bucket = size_log2 - 12;
assert(bucket < ARRAY_SIZE(pool->free_list));
void *next_free_void;
if (anv_ptr_free_list_pop(&pool->free_list[bucket], &next_free_void)) {
struct bo_pool_bo_link *next_free = next_free_void;
*bo = VG_NOACCESS_READ(&next_free->bo);
assert(bo->gem_handle);
assert(bo->map == next_free);
assert(size <= bo->size);
VG(VALGRIND_MEMPOOL_ALLOC(pool, bo->map, size));
return VK_SUCCESS;
}
struct anv_bo new_bo;
result = anv_bo_init_new(&new_bo, pool->device, pow2_size);
if (result != VK_SUCCESS)
return result;
new_bo.flags = pool->bo_flags;
if (!anv_vma_alloc(pool->device, &new_bo))
return vk_error(VK_ERROR_OUT_OF_DEVICE_MEMORY);
assert(new_bo.size == pow2_size);
new_bo.map = anv_gem_mmap(pool->device, new_bo.gem_handle, 0, pow2_size, 0);
if (new_bo.map == MAP_FAILED) {
anv_gem_close(pool->device, new_bo.gem_handle);
anv_vma_free(pool->device, &new_bo);
return vk_error(VK_ERROR_MEMORY_MAP_FAILED);
}
*bo = new_bo;
VG(VALGRIND_MEMPOOL_ALLOC(pool, bo->map, size));
return VK_SUCCESS;
}
void
anv_bo_pool_free(struct anv_bo_pool *pool, const struct anv_bo *bo_in)
{
/* Make a copy in case the anv_bo happens to be storred in the BO */
struct anv_bo bo = *bo_in;
VG(VALGRIND_MEMPOOL_FREE(pool, bo.map));
struct bo_pool_bo_link *link = bo.map;
VG_NOACCESS_WRITE(&link->bo, bo);
assert(util_is_power_of_two_or_zero(bo.size));
const unsigned size_log2 = ilog2_round_up(bo.size);
const unsigned bucket = size_log2 - 12;
assert(bucket < ARRAY_SIZE(pool->free_list));
anv_ptr_free_list_push(&pool->free_list[bucket], link);
}
// Scratch pool
void
anv_scratch_pool_init(struct anv_device *device, struct anv_scratch_pool *pool)
{
memset(pool, 0, sizeof(*pool));
}
void
anv_scratch_pool_finish(struct anv_device *device, struct anv_scratch_pool *pool)
{
for (unsigned s = 0; s < MESA_SHADER_STAGES; s++) {
for (unsigned i = 0; i < 16; i++) {
struct anv_scratch_bo *bo = &pool->bos[i][s];
if (bo->exists > 0) {
anv_vma_free(device, &bo->bo);
anv_gem_close(device, bo->bo.gem_handle);
}
}
}
}
struct anv_bo *
anv_scratch_pool_alloc(struct anv_device *device, struct anv_scratch_pool *pool,
gl_shader_stage stage, unsigned per_thread_scratch)
{
if (per_thread_scratch == 0)
return NULL;
unsigned scratch_size_log2 = ffs(per_thread_scratch / 2048);
assert(scratch_size_log2 < 16);
struct anv_scratch_bo *bo = &pool->bos[scratch_size_log2][stage];
/* We can use "exists" to shortcut and ignore the critical section */
if (bo->exists)
return &bo->bo;
pthread_mutex_lock(&device->mutex);
__sync_synchronize();
if (bo->exists) {
pthread_mutex_unlock(&device->mutex);
return &bo->bo;
}
const struct anv_physical_device *physical_device =
&device->instance->physicalDevice;
const struct gen_device_info *devinfo = &physical_device->info;
const unsigned subslices = MAX2(physical_device->subslice_total, 1);
unsigned scratch_ids_per_subslice;
if (devinfo->is_haswell) {
/* WaCSScratchSize:hsw
*
* Haswell's scratch space address calculation appears to be sparse
* rather than tightly packed. The Thread ID has bits indicating
* which subslice, EU within a subslice, and thread within an EU it
* is. There's a maximum of two slices and two subslices, so these
* can be stored with a single bit. Even though there are only 10 EUs
* per subslice, this is stored in 4 bits, so there's an effective
* maximum value of 16 EUs. Similarly, although there are only 7
* threads per EU, this is stored in a 3 bit number, giving an
* effective maximum value of 8 threads per EU.
*
* This means that we need to use 16 * 8 instead of 10 * 7 for the
* number of threads per subslice.
*/
scratch_ids_per_subslice = 16 * 8;
} else if (devinfo->is_cherryview) {
/* Cherryview devices have either 6 or 8 EUs per subslice, and each EU
* has 7 threads. The 6 EU devices appear to calculate thread IDs as if
* it had 8 EUs.
*/
scratch_ids_per_subslice = 8 * 7;
} else {
scratch_ids_per_subslice = devinfo->max_cs_threads;
}
uint32_t max_threads[] = {
[MESA_SHADER_VERTEX] = devinfo->max_vs_threads,
[MESA_SHADER_TESS_CTRL] = devinfo->max_tcs_threads,
[MESA_SHADER_TESS_EVAL] = devinfo->max_tes_threads,
[MESA_SHADER_GEOMETRY] = devinfo->max_gs_threads,
[MESA_SHADER_FRAGMENT] = devinfo->max_wm_threads,
[MESA_SHADER_COMPUTE] = scratch_ids_per_subslice * subslices,
};
uint32_t size = per_thread_scratch * max_threads[stage];
anv_bo_init_new(&bo->bo, device, size);
/* Even though the Scratch base pointers in 3DSTATE_*S are 64 bits, they
* are still relative to the general state base address. When we emit
* STATE_BASE_ADDRESS, we set general state base address to 0 and the size
* to the maximum (1 page under 4GB). This allows us to just place the
* scratch buffers anywhere we wish in the bottom 32 bits of address space
* and just set the scratch base pointer in 3DSTATE_*S using a relocation.
* However, in order to do so, we need to ensure that the kernel does not
* place the scratch BO above the 32-bit boundary.
*
* NOTE: Technically, it can't go "anywhere" because the top page is off
* limits. However, when EXEC_OBJECT_SUPPORTS_48B_ADDRESS is set, the
* kernel allocates space using
*
* end = min_t(u64, end, (1ULL << 32) - I915_GTT_PAGE_SIZE);
*
* so nothing will ever touch the top page.
*/
assert(!(bo->bo.flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS));
if (device->instance->physicalDevice.has_exec_async)
bo->bo.flags |= EXEC_OBJECT_ASYNC;
if (device->instance->physicalDevice.use_softpin)
bo->bo.flags |= EXEC_OBJECT_PINNED;
anv_vma_alloc(device, &bo->bo);
/* Set the exists last because it may be read by other threads */
__sync_synchronize();
bo->exists = true;
pthread_mutex_unlock(&device->mutex);
return &bo->bo;
}
struct anv_cached_bo {
struct anv_bo bo;
uint32_t refcount;
};
VkResult
anv_bo_cache_init(struct anv_bo_cache *cache)
{
cache->bo_map = _mesa_hash_table_create(NULL, _mesa_hash_pointer,
_mesa_key_pointer_equal);
if (!cache->bo_map)
return vk_error(VK_ERROR_OUT_OF_HOST_MEMORY);
if (pthread_mutex_init(&cache->mutex, NULL)) {
_mesa_hash_table_destroy(cache->bo_map, NULL);
return vk_errorf(NULL, NULL, VK_ERROR_OUT_OF_HOST_MEMORY,
"pthread_mutex_init failed: %m");
}
return VK_SUCCESS;
}
void
anv_bo_cache_finish(struct anv_bo_cache *cache)
{
_mesa_hash_table_destroy(cache->bo_map, NULL);
pthread_mutex_destroy(&cache->mutex);
}
static struct anv_cached_bo *
anv_bo_cache_lookup_locked(struct anv_bo_cache *cache, uint32_t gem_handle)
{
struct hash_entry *entry =
_mesa_hash_table_search(cache->bo_map,
(const void *)(uintptr_t)gem_handle);
if (!entry)
return NULL;
struct anv_cached_bo *bo = (struct anv_cached_bo *)entry->data;
assert(bo->bo.gem_handle == gem_handle);
return bo;
}
UNUSED static struct anv_bo *
anv_bo_cache_lookup(struct anv_bo_cache *cache, uint32_t gem_handle)
{
pthread_mutex_lock(&cache->mutex);
struct anv_cached_bo *bo = anv_bo_cache_lookup_locked(cache, gem_handle);
pthread_mutex_unlock(&cache->mutex);
return bo ? &bo->bo : NULL;
}
#define ANV_BO_CACHE_SUPPORTED_FLAGS \
(EXEC_OBJECT_WRITE | \
EXEC_OBJECT_ASYNC | \
EXEC_OBJECT_SUPPORTS_48B_ADDRESS | \
EXEC_OBJECT_PINNED | \
ANV_BO_EXTERNAL)
VkResult
anv_bo_cache_alloc(struct anv_device *device,
struct anv_bo_cache *cache,
uint64_t size, uint64_t bo_flags,
struct anv_bo **bo_out)
{
assert(bo_flags == (bo_flags & ANV_BO_CACHE_SUPPORTED_FLAGS));
struct anv_cached_bo *bo =
vk_alloc(&device->alloc, sizeof(struct anv_cached_bo), 8,
VK_SYSTEM_ALLOCATION_SCOPE_OBJECT);
if (!bo)
return vk_error(VK_ERROR_OUT_OF_HOST_MEMORY);
bo->refcount = 1;
/* The kernel is going to give us whole pages anyway */
size = align_u64(size, 4096);
VkResult result = anv_bo_init_new(&bo->bo, device, size);
if (result != VK_SUCCESS) {
vk_free(&device->alloc, bo);
return result;
}
bo->bo.flags = bo_flags;
if (!anv_vma_alloc(device, &bo->bo)) {
anv_gem_close(device, bo->bo.gem_handle);
vk_free(&device->alloc, bo);
return vk_errorf(device->instance, NULL,
VK_ERROR_OUT_OF_DEVICE_MEMORY,
"failed to allocate virtual address for BO");
}
assert(bo->bo.gem_handle);
pthread_mutex_lock(&cache->mutex);
_mesa_hash_table_insert(cache->bo_map,
(void *)(uintptr_t)bo->bo.gem_handle, bo);
pthread_mutex_unlock(&cache->mutex);
*bo_out = &bo->bo;
return VK_SUCCESS;
}
VkResult
anv_bo_cache_import(struct anv_device *device,
struct anv_bo_cache *cache,
int fd, uint64_t bo_flags,
struct anv_bo **bo_out)
{
assert(bo_flags == (bo_flags & ANV_BO_CACHE_SUPPORTED_FLAGS));
assert(bo_flags & ANV_BO_EXTERNAL);
pthread_mutex_lock(&cache->mutex);
uint32_t gem_handle = anv_gem_fd_to_handle(device, fd);
if (!gem_handle) {
pthread_mutex_unlock(&cache->mutex);
return vk_error(VK_ERROR_INVALID_EXTERNAL_HANDLE_KHR);
}
struct anv_cached_bo *bo = anv_bo_cache_lookup_locked(cache, gem_handle);
if (bo) {
/* We have to be careful how we combine flags so that it makes sense.
* Really, though, if we get to this case and it actually matters, the
* client has imported a BO twice in different ways and they get what
* they have coming.
*/
uint64_t new_flags = ANV_BO_EXTERNAL;
new_flags |= (bo->bo.flags | bo_flags) & EXEC_OBJECT_WRITE;
new_flags |= (bo->bo.flags & bo_flags) & EXEC_OBJECT_ASYNC;
new_flags |= (bo->bo.flags & bo_flags) & EXEC_OBJECT_SUPPORTS_48B_ADDRESS;
new_flags |= (bo->bo.flags | bo_flags) & EXEC_OBJECT_PINNED;
/* It's theoretically possible for a BO to get imported such that it's
* both pinned and not pinned. The only way this can happen is if it
* gets imported as both a semaphore and a memory object and that would
* be an application error. Just fail out in that case.
*/
if ((bo->bo.flags & EXEC_OBJECT_PINNED) !=
(bo_flags & EXEC_OBJECT_PINNED)) {
pthread_mutex_unlock(&cache->mutex);
return vk_errorf(device->instance, NULL,
VK_ERROR_INVALID_EXTERNAL_HANDLE,
"The same BO was imported two different ways");
}
/* It's also theoretically possible that someone could export a BO from
* one heap and import it into another or to import the same BO into two
* different heaps. If this happens, we could potentially end up both
* allowing and disallowing 48-bit addresses. There's not much we can
* do about it if we're pinning so we just throw an error and hope no
* app is actually that stupid.
*/
if ((new_flags & EXEC_OBJECT_PINNED) &&
(bo->bo.flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS) !=
(bo_flags & EXEC_OBJECT_SUPPORTS_48B_ADDRESS)) {
pthread_mutex_unlock(&cache->mutex);
return vk_errorf(device->instance, NULL,
VK_ERROR_INVALID_EXTERNAL_HANDLE,
"The same BO was imported on two different heaps");
}
bo->bo.flags = new_flags;
__sync_fetch_and_add(&bo->refcount, 1);
} else {
off_t size = lseek(fd, 0, SEEK_END);
if (size == (off_t)-1) {
anv_gem_close(device, gem_handle);
pthread_mutex_unlock(&cache->mutex);
return vk_error(VK_ERROR_INVALID_EXTERNAL_HANDLE_KHR);
}
bo = vk_alloc(&device->alloc, sizeof(struct anv_cached_bo), 8,
VK_SYSTEM_ALLOCATION_SCOPE_OBJECT);
if (!bo) {
anv_gem_close(device, gem_handle);
pthread_mutex_unlock(&cache->mutex);
return vk_error(VK_ERROR_OUT_OF_HOST_MEMORY);
}
bo->refcount = 1;
anv_bo_init(&bo->bo, gem_handle, size);
bo->bo.flags = bo_flags;
if (!anv_vma_alloc(device, &bo->bo)) {
anv_gem_close(device, bo->bo.gem_handle);
pthread_mutex_unlock(&cache->mutex);
vk_free(&device->alloc, bo);
return vk_errorf(device->instance, NULL,
VK_ERROR_OUT_OF_DEVICE_MEMORY,
"failed to allocate virtual address for BO");
}
_mesa_hash_table_insert(cache->bo_map, (void *)(uintptr_t)gem_handle, bo);
}
pthread_mutex_unlock(&cache->mutex);
*bo_out = &bo->bo;
return VK_SUCCESS;
}
VkResult
anv_bo_cache_export(struct anv_device *device,
struct anv_bo_cache *cache,
struct anv_bo *bo_in, int *fd_out)
{
assert(anv_bo_cache_lookup(cache, bo_in->gem_handle) == bo_in);
struct anv_cached_bo *bo = (struct anv_cached_bo *)bo_in;
/* This BO must have been flagged external in order for us to be able
* to export it. This is done based on external options passed into
* anv_AllocateMemory.
*/
assert(bo->bo.flags & ANV_BO_EXTERNAL);
int fd = anv_gem_handle_to_fd(device, bo->bo.gem_handle);
if (fd < 0)
return vk_error(VK_ERROR_TOO_MANY_OBJECTS);
*fd_out = fd;
return VK_SUCCESS;
}
static bool
atomic_dec_not_one(uint32_t *counter)
{
uint32_t old, val;
val = *counter;
while (1) {
if (val == 1)
return false;
old = __sync_val_compare_and_swap(counter, val, val - 1);
if (old == val)
return true;
val = old;
}
}
void
anv_bo_cache_release(struct anv_device *device,
struct anv_bo_cache *cache,
struct anv_bo *bo_in)
{
assert(anv_bo_cache_lookup(cache, bo_in->gem_handle) == bo_in);
struct anv_cached_bo *bo = (struct anv_cached_bo *)bo_in;
/* Try to decrement the counter but don't go below one. If this succeeds
* then the refcount has been decremented and we are not the last
* reference.
*/
if (atomic_dec_not_one(&bo->refcount))
return;
pthread_mutex_lock(&cache->mutex);
/* We are probably the last reference since our attempt to decrement above
* failed. However, we can't actually know until we are inside the mutex.
* Otherwise, someone could import the BO between the decrement and our
* taking the mutex.
*/
if (unlikely(__sync_sub_and_fetch(&bo->refcount, 1) > 0)) {
/* Turns out we're not the last reference. Unlock and bail. */
pthread_mutex_unlock(&cache->mutex);
return;
}
struct hash_entry *entry =
_mesa_hash_table_search(cache->bo_map,
(const void *)(uintptr_t)bo->bo.gem_handle);
assert(entry);
_mesa_hash_table_remove(cache->bo_map, entry);
if (bo->bo.map)
anv_gem_munmap(bo->bo.map, bo->bo.size);
anv_vma_free(device, &bo->bo);
anv_gem_close(device, bo->bo.gem_handle);
/* Don't unlock until we've actually closed the BO. The whole point of
* the BO cache is to ensure that we correctly handle races with creating
* and releasing GEM handles and we don't want to let someone import the BO
* again between mutex unlock and closing the GEM handle.
*/
pthread_mutex_unlock(&cache->mutex);
vk_free(&device->alloc, bo);
}