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authorLinus Torvalds <torvalds@linux-foundation.org>2024-01-11 13:46:50 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2024-01-11 13:46:50 -0800
commit893e2f9eac9ec8d65a5ae2d99656d5e9f7bd76e2 (patch)
tree14e0590d2e0d7b5993251615fefc706175cdfeaf /kernel/dma
parent457e4f99765cc41d0b90e1385f51b848d6a921d0 (diff)
parentb07bc2347672cc8c7293c64499f1488278c5ca3d (diff)
Merge tag 'dma-mapping-6.8-2024-01-08' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig: - reduce area lock contention for non-primary IO TLB pools (Petr Tesarik) - don't store redundant offsets in the dma_ranges stuctures (Robin Murphy) - clear dev->dma_mem when freeing per-device pools (Joakim Zhang) * tag 'dma-mapping-6.8-2024-01-08' of git://git.infradead.org/users/hch/dma-mapping: dma-mapping: clear dev->dma_mem to NULL after freeing it swiotlb: reduce area lock contention for non-primary IO TLB pools dma-mapping: don't store redundant offsets
Diffstat (limited to 'kernel/dma')
-rw-r--r--kernel/dma/coherent.c4
-rw-r--r--kernel/dma/direct.c1
-rw-r--r--kernel/dma/swiotlb.c90
3 files changed, 58 insertions, 37 deletions
diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
index c21abc77c53e..ff5683a57f77 100644
--- a/kernel/dma/coherent.c
+++ b/kernel/dma/coherent.c
@@ -132,8 +132,10 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
void dma_release_coherent_memory(struct device *dev)
{
- if (dev)
+ if (dev) {
_dma_release_coherent_memory(dev->dma_mem);
+ dev->dma_mem = NULL;
+ }
}
static void *__dma_alloc_from_coherent(struct device *dev,
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 73c95815789a..98b2e192fd69 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -677,7 +677,6 @@ int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
return -ENOMEM;
map[0].cpu_start = cpu_start;
map[0].dma_start = dma_start;
- map[0].offset = offset;
map[0].size = size;
dev->dma_range_map = map;
return 0;
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 176078bf2215..97c298b210bc 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -957,7 +957,7 @@ static void dec_used(struct io_tlb_mem *mem, unsigned int nslots)
#endif /* CONFIG_DEBUG_FS */
/**
- * swiotlb_area_find_slots() - search for slots in one IO TLB memory area
+ * swiotlb_search_pool_area() - search one memory area in one pool
* @dev: Device which maps the buffer.
* @pool: Memory pool to be searched.
* @area_index: Index of the IO TLB memory area to be searched.
@@ -972,7 +972,7 @@ static void dec_used(struct io_tlb_mem *mem, unsigned int nslots)
*
* Return: Index of the first allocated slot, or -1 on error.
*/
-static int swiotlb_area_find_slots(struct device *dev, struct io_tlb_pool *pool,
+static int swiotlb_search_pool_area(struct device *dev, struct io_tlb_pool *pool,
int area_index, phys_addr_t orig_addr, size_t alloc_size,
unsigned int alloc_align_mask)
{
@@ -1066,41 +1066,50 @@ found:
return slot_index;
}
+#ifdef CONFIG_SWIOTLB_DYNAMIC
+
/**
- * swiotlb_pool_find_slots() - search for slots in one memory pool
+ * swiotlb_search_area() - search one memory area in all pools
* @dev: Device which maps the buffer.
- * @pool: Memory pool to be searched.
+ * @start_cpu: Start CPU number.
+ * @cpu_offset: Offset from @start_cpu.
* @orig_addr: Original (non-bounced) IO buffer address.
* @alloc_size: Total requested size of the bounce buffer,
* including initial alignment padding.
* @alloc_align_mask: Required alignment of the allocated buffer.
+ * @retpool: Used memory pool, updated on return.
*
- * Search through one memory pool to find a sequence of slots that match the
+ * Search one memory area in all pools for a sequence of slots that match the
* allocation constraints.
*
* Return: Index of the first allocated slot, or -1 on error.
*/
-static int swiotlb_pool_find_slots(struct device *dev, struct io_tlb_pool *pool,
- phys_addr_t orig_addr, size_t alloc_size,
- unsigned int alloc_align_mask)
+static int swiotlb_search_area(struct device *dev, int start_cpu,
+ int cpu_offset, phys_addr_t orig_addr, size_t alloc_size,
+ unsigned int alloc_align_mask, struct io_tlb_pool **retpool)
{
- int start = raw_smp_processor_id() & (pool->nareas - 1);
- int i = start, index;
-
- do {
- index = swiotlb_area_find_slots(dev, pool, i, orig_addr,
- alloc_size, alloc_align_mask);
- if (index >= 0)
- return index;
- if (++i >= pool->nareas)
- i = 0;
- } while (i != start);
+ struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
+ struct io_tlb_pool *pool;
+ int area_index;
+ int index = -1;
- return -1;
+ rcu_read_lock();
+ list_for_each_entry_rcu(pool, &mem->pools, node) {
+ if (cpu_offset >= pool->nareas)
+ continue;
+ area_index = (start_cpu + cpu_offset) & (pool->nareas - 1);
+ index = swiotlb_search_pool_area(dev, pool, area_index,
+ orig_addr, alloc_size,
+ alloc_align_mask);
+ if (index >= 0) {
+ *retpool = pool;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ return index;
}
-#ifdef CONFIG_SWIOTLB_DYNAMIC
-
/**
* swiotlb_find_slots() - search for slots in the whole swiotlb
* @dev: Device which maps the buffer.
@@ -1124,18 +1133,17 @@ static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr,
unsigned long nslabs;
unsigned long flags;
u64 phys_limit;
+ int cpu, i;
int index;
- rcu_read_lock();
- list_for_each_entry_rcu(pool, &mem->pools, node) {
- index = swiotlb_pool_find_slots(dev, pool, orig_addr,
- alloc_size, alloc_align_mask);
- if (index >= 0) {
- rcu_read_unlock();
+ cpu = raw_smp_processor_id();
+ for (i = 0; i < default_nareas; ++i) {
+ index = swiotlb_search_area(dev, cpu, i, orig_addr, alloc_size,
+ alloc_align_mask, &pool);
+ if (index >= 0)
goto found;
- }
}
- rcu_read_unlock();
+
if (!mem->can_grow)
return -1;
@@ -1148,8 +1156,8 @@ static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr,
if (!pool)
return -1;
- index = swiotlb_pool_find_slots(dev, pool, orig_addr,
- alloc_size, alloc_align_mask);
+ index = swiotlb_search_pool_area(dev, pool, 0, orig_addr,
+ alloc_size, alloc_align_mask);
if (index < 0) {
swiotlb_dyn_free(&pool->rcu);
return -1;
@@ -1192,9 +1200,21 @@ static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr,
size_t alloc_size, unsigned int alloc_align_mask,
struct io_tlb_pool **retpool)
{
- *retpool = &dev->dma_io_tlb_mem->defpool;
- return swiotlb_pool_find_slots(dev, *retpool,
- orig_addr, alloc_size, alloc_align_mask);
+ struct io_tlb_pool *pool;
+ int start, i;
+ int index;
+
+ *retpool = pool = &dev->dma_io_tlb_mem->defpool;
+ i = start = raw_smp_processor_id() & (pool->nareas - 1);
+ do {
+ index = swiotlb_search_pool_area(dev, pool, i, orig_addr,
+ alloc_size, alloc_align_mask);
+ if (index >= 0)
+ return index;
+ if (++i >= pool->nareas)
+ i = 0;
+ } while (i != start);
+ return -1;
}
#endif /* CONFIG_SWIOTLB_DYNAMIC */