[PATCH 11/13] swiotlb: move orig addr and size validation into swiotlb_bounce
Khalid Elmously
khalid.elmously at canonical.com
Wed Oct 13 06:50:05 UTC 2021
From: Christoph Hellwig <hch at lst.de>
BugLink: https://bugs.launchpad.net/bugs/1943902
Move the code to find and validate the original buffer address and size
from the callers into swiotlb_bounce. This means a tiny bit of extra
work in the swiotlb_map path, but avoids code duplication and a leads to
a better code structure.
Signed-off-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
(backported from commit 2bdba622c351259317b0294c6e9fe243b2404316)
[ kmously: many context changes. The most notable thing is that
there is no io_tlb_orig_size[] global array which means that int alloc_size
in swiotlb_bounce() cannot be set. This is only used for a new WARN
about overallocation and is safe to omit (rather than attempt to backport
the big mess of multiple refactorings) ]
Signed-off-by: Khalid Elmously <khalid.elmously at canonical.com>
---
kernel/dma/swiotlb.c | 33 ++++++++++++++-------------------
1 file changed, 14 insertions(+), 19 deletions(-)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index c048c9c0ecbc8..a942c629b00b1 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -416,12 +416,17 @@ void __init swiotlb_exit(void)
/*
* Bounce: copy the swiotlb buffer from or back to the original dma location
*/
-static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr,
- size_t size, enum dma_data_direction dir)
+static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size,
+ enum dma_data_direction dir)
{
+ int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT;
+ phys_addr_t orig_addr = io_tlb_orig_addr[index];
unsigned long pfn = PFN_DOWN(orig_addr);
unsigned char *vaddr = phys_to_virt(tlb_addr);
+ if (orig_addr == INVALID_PHYS_ADDR)
+ return;
+
if (PageHighMem(pfn_to_page(pfn))) {
/* The buffer does not have a mapping. Map it in and copy */
unsigned int offset = orig_addr & ~PAGE_MASK;
@@ -599,7 +604,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
tlb_addr = slot_addr(io_tlb_start, index) + offset;
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
- swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE);
+ swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_TO_DEVICE);
return tlb_addr;
}
@@ -612,17 +617,15 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
{
unsigned long flags;
unsigned int offset = swiotlb_align_offset(hwdev, tlb_addr);
- int i, count, nslots = nr_slots(alloc_size + offset);
int index = (tlb_addr - offset - io_tlb_start) >> IO_TLB_SHIFT;
- phys_addr_t orig_addr = io_tlb_orig_addr[index];
+ int i, count, nslots = nr_slots(alloc_size + offset);
/*
* First, sync the memory before unmapping the entry
*/
- if (orig_addr != INVALID_PHYS_ADDR &&
- !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
- ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
- swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_FROM_DEVICE);
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
+ (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
+ swiotlb_bounce(hwdev, tlb_addr, mapping_size, DMA_FROM_DEVICE);
/*
* Return the buffer to the free list by setting the corresponding
@@ -661,24 +664,16 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr,
size_t size, enum dma_data_direction dir,
enum dma_sync_target target)
{
- int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT;
- phys_addr_t orig_addr = io_tlb_orig_addr[index];
-
- if (orig_addr == INVALID_PHYS_ADDR)
- return;
-
switch (target) {
case SYNC_FOR_CPU:
if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
- swiotlb_bounce(orig_addr, tlb_addr,
- size, DMA_FROM_DEVICE);
+ swiotlb_bounce(hwdev, tlb_addr, size, DMA_FROM_DEVICE);
else
BUG_ON(dir != DMA_TO_DEVICE);
break;
case SYNC_FOR_DEVICE:
if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
- swiotlb_bounce(orig_addr, tlb_addr,
- size, DMA_TO_DEVICE);
+ swiotlb_bounce(hwdev, tlb_addr, size, DMA_TO_DEVICE);
else
BUG_ON(dir != DMA_FROM_DEVICE);
break;
--
2.17.1
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