bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-18 06:44:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

Merge tag 'dma-mapping-6.10-2024-05-20' of git://git.infradead.org/users/hch/dma-mapping

Browse Source 
Pull dma-mapping updates from Christoph Hellwig:

 - optimize DMA sync calls when they are no-ops (Alexander Lobakin)

 - fix swiotlb padding for untrusted devices (Michael Kelley)

 - add documentation for swiotb (Michael Kelley)

* tag 'dma-mapping-6.10-2024-05-20' of git://git.infradead.org/users/hch/dma-mapping:
  dma: fix DMA sync for drivers not calling dma_set_mask*()
  xsk: use generic DMA sync shortcut instead of a custom one
  page_pool: check for DMA sync shortcut earlier
  page_pool: don't use driver-set flags field directly
  page_pool: make sure frag API fields don't span between cachelines
  iommu/dma: avoid expensive indirect calls for sync operations
  dma: avoid redundant calls for sync operations
  dma: compile-out DMA sync op calls when not used
  iommu/dma: fix zeroing of bounce buffer padding used by untrusted devices
  swiotlb: remove alloc_size argument to swiotlb_tbl_map_single()
  Documentation/core-api: add swiotlb documentation
This commit is contained in:
Linus Torvalds
2024-05-20 10:23:39 -07:00
parent 6e51b4b5bb a6016aac52
commit daa121128a
27 changed files with 634 additions and 163 deletions
Download Patch File Download Diff File Expand all files Collapse all files

62
kernel/dma/swiotlb.c
View File

@@ -1340,15 +1340,40 @@ static unsigned long mem_used(struct io_tlb_mem *mem)
#endif /* CONFIG_DEBUG_FS */
/**
* swiotlb_tbl_map_single() - bounce buffer map a single contiguous physical area
* @dev: Device which maps the buffer.
* @orig_addr: Original (non-bounced) physical IO buffer address
* @mapping_size: Requested size of the actual bounce buffer, excluding
* any pre- or post-padding for alignment
* @alloc_align_mask: Required start and end alignment of the allocated buffer
* @dir: DMA direction
* @attrs: Optional DMA attributes for the map operation
*
* Find and allocate a suitable sequence of IO TLB slots for the request.
* The allocated space starts at an alignment specified by alloc_align_mask,
* and the size of the allocated space is rounded up so that the total amount
* of allocated space is a multiple of (alloc_align_mask + 1). If
* alloc_align_mask is zero, the allocated space may be at any alignment and
* the size is not rounded up.
*
* The returned address is within the allocated space and matches the bits
* of orig_addr that are specified in the DMA min_align_mask for the device. As
* such, this returned address may be offset from the beginning of the allocated
* space. The bounce buffer space starting at the returned address for
* mapping_size bytes is initialized to the contents of the original IO buffer
* area. Any pre-padding (due to an offset) and any post-padding (due to
* rounding-up the size) is not initialized.
*/
phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
size_t mapping_size, size_t alloc_size,
unsigned int alloc_align_mask, enum dma_data_direction dir,
unsigned long attrs)
size_t mapping_size, unsigned int alloc_align_mask,
enum dma_data_direction dir, unsigned long attrs)
{
struct io_tlb_mem *mem = dev->dma_io_tlb_mem;
unsigned int offset;
struct io_tlb_pool *pool;
unsigned int i;
size_t size;
int index;
phys_addr_t tlb_addr;
unsigned short pad_slots;
@@ -1362,23 +1387,33 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
if (cc_platform_has(CC_ATTR_MEM_ENCRYPT))
pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n");
if (mapping_size > alloc_size) {
dev_warn_once(dev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)",
mapping_size, alloc_size);
return (phys_addr_t)DMA_MAPPING_ERROR;
}
/*
* The default swiotlb memory pool is allocated with PAGE_SIZE
* alignment. If a mapping is requested with larger alignment,
* the mapping may be unable to use the initial slot(s) in all
* sets of IO_TLB_SEGSIZE slots. In such case, a mapping request
* of or near the maximum mapping size would always fail.
*/
dev_WARN_ONCE(dev, alloc_align_mask > ~PAGE_MASK,
"Alloc alignment may prevent fulfilling requests with max mapping_size\n");
offset = swiotlb_align_offset(dev, alloc_align_mask, orig_addr);
index = swiotlb_find_slots(dev, orig_addr,
alloc_size + offset, alloc_align_mask, &pool);
size = ALIGN(mapping_size + offset, alloc_align_mask + 1);
index = swiotlb_find_slots(dev, orig_addr, size, alloc_align_mask, &pool);
if (index == -1) {
if (!(attrs & DMA_ATTR_NO_WARN))
dev_warn_ratelimited(dev,
"swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n",
alloc_size, mem->nslabs, mem_used(mem));
size, mem->nslabs, mem_used(mem));
return (phys_addr_t)DMA_MAPPING_ERROR;
}
/*
* If dma_skip_sync was set, reset it on first SWIOTLB buffer
* mapping to always sync SWIOTLB buffers.
*/
dma_reset_need_sync(dev);
/*
* Save away the mapping from the original address to the DMA address.
* This is needed when we sync the memory. Then we sync the buffer if
@@ -1388,7 +1423,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
offset &= (IO_TLB_SIZE - 1);
index += pad_slots;
pool->slots[index].pad_slots = pad_slots;
for (i = 0; i < nr_slots(alloc_size + offset); i++)
for (i = 0; i < (nr_slots(size) - pad_slots); i++)
pool->slots[index + i].orig_addr = slot_addr(orig_addr, i);
tlb_addr = slot_addr(pool->start, index) + offset;
/*
@@ -1543,8 +1578,7 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size,
trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size);
swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, 0, dir,
attrs);
swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, 0, dir, attrs);
if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;