Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'dma-mapping-6.3-2023-03-31' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fixes from Christoph Hellwig:
- fix for swiotlb deadlock due to wrong alignment checks (GuoRui.Yu,
Petr Tesarik)
* tag 'dma-mapping-6.3-2023-03-31' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: fix slot alignment checks
swiotlb: use wrap_area_index() instead of open-coding it
swiotlb: fix the deadlock in swiotlb_do_find_slots
+16
-13
+16
-13
kernel/dma/swiotlb.c
+16
-13
kernel/dma/swiotlb.c
···
625
625
unsigned int iotlb_align_mask =
626
626
dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1);
627
627
unsigned int nslots = nr_slots(alloc_size), stride;
628
-
unsigned int index, wrap, count = 0, i;
629
628
unsigned int offset = swiotlb_align_offset(dev, orig_addr);
629
+
unsigned int index, slots_checked, count = 0, i;
630
630
unsigned long flags;
631
631
unsigned int slot_base;
632
632
unsigned int slot_index;
···
635
635
BUG_ON(area_index >= mem->nareas);
636
636
637
637
/*
638
+
* For allocations of PAGE_SIZE or larger only look for page aligned
639
+
* allocations.
640
+
*/
641
+
if (alloc_size >= PAGE_SIZE)
642
+
iotlb_align_mask &= PAGE_MASK;
643
+
iotlb_align_mask &= alloc_align_mask;
644
+
645
+
/*
638
646
* For mappings with an alignment requirement don't bother looping to
639
-
* unaligned slots once we found an aligned one. For allocations of
640
-
* PAGE_SIZE or larger only look for page aligned allocations.
647
+
* unaligned slots once we found an aligned one.
641
648
*/
642
649
stride = (iotlb_align_mask >> IO_TLB_SHIFT) + 1;
643
-
if (alloc_size >= PAGE_SIZE)
644
-
stride = max(stride, stride << (PAGE_SHIFT - IO_TLB_SHIFT));
645
-
stride = max(stride, (alloc_align_mask >> IO_TLB_SHIFT) + 1);
646
650
647
651
spin_lock_irqsave(&area->lock, flags);
648
652
if (unlikely(nslots > mem->area_nslabs - area->used))
649
653
goto not_found;
650
654
651
655
slot_base = area_index * mem->area_nslabs;
652
-
index = wrap = wrap_area_index(mem, ALIGN(area->index, stride));
656
+
index = area->index;
653
657
654
-
do {
658
+
for (slots_checked = 0; slots_checked < mem->area_nslabs; ) {
655
659
slot_index = slot_base + index;
656
660
657
661
if (orig_addr &&
658
662
(slot_addr(tbl_dma_addr, slot_index) &
659
663
iotlb_align_mask) != (orig_addr & iotlb_align_mask)) {
660
664
index = wrap_area_index(mem, index + 1);
665
+
slots_checked++;
661
666
continue;
662
667
}
663
668
···
678
673
goto found;
679
674
}
680
675
index = wrap_area_index(mem, index + stride);
681
-
} while (index != wrap);
676
+
slots_checked += stride;
677
+
}
682
678
683
679
not_found:
684
680
spin_unlock_irqrestore(&area->lock, flags);
···
699
693
/*
700
694
* Update the indices to avoid searching in the next round.
701
695
*/
702
-
if (index + nslots < mem->area_nslabs)
703
-
area->index = index + nslots;
704
-
else
705
-
area->index = 0;
696
+
area->index = wrap_area_index(mem, index + nslots);
706
697
area->used += nslots;
707
698
spin_unlock_irqrestore(&area->lock, flags);
708
699
return slot_index;