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Revert "swiotlb: refactor swiotlb_tbl_map_single"

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This reverts commit 25ed8827cf.

Fixes the ABI issues in 5.10.35 that at the moment, we can't handle due
to the KABI freeze.  These are not patches that mean much for android
systems, and will be reverted the next KABI "reset" point.

Bug: 161946584
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I9928cdc06a26b9db3052b93067c557011e53f735
This commit is contained in:
Greg Kroah-Hartman 2021-05-08 13:00:49 +02:00
commit 0fb49e91d4
1 changed files with 103 additions and 102 deletions
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205
kernel/dma/swiotlb.c
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@ -452,99 +452,19 @@ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr,
}
}
#define slot_addr(start, idx) ((start) + ((idx) << IO_TLB_SHIFT))
/*
* Carefully handle integer overflow which can occur when boundary_mask == ~0UL.
*/
static inline unsigned long get_max_slots(unsigned long boundary_mask)
{
if (boundary_mask == ~0UL)
return 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
return nr_slots(boundary_mask + 1);
}
static unsigned int wrap_index(unsigned int index)
{
if (index >= io_tlb_nslabs)
return 0;
return index;
}
/*
* Find a suitable number of IO TLB entries size that will fit this request and
* allocate a buffer from that IO TLB pool.
*/
static int find_slots(struct device *dev, size_t alloc_size)
{
unsigned long boundary_mask = dma_get_seg_boundary(dev);
dma_addr_t tbl_dma_addr =
phys_to_dma_unencrypted(dev, io_tlb_start) & boundary_mask;
unsigned long max_slots = get_max_slots(boundary_mask);
unsigned int nslots = nr_slots(alloc_size), stride = 1;
unsigned int index, wrap, count = 0, i;
unsigned long flags;
BUG_ON(!nslots);
/*
* For mappings greater than or equal to a page, we limit the stride
* (and hence alignment) to a page size.
*/
if (alloc_size >= PAGE_SIZE)
stride <<= (PAGE_SHIFT - IO_TLB_SHIFT);
spin_lock_irqsave(&io_tlb_lock, flags);
if (unlikely(nslots > io_tlb_nslabs - io_tlb_used))
goto not_found;
index = wrap = wrap_index(ALIGN(io_tlb_index, stride));
do {
/*
* If we find a slot that indicates we have 'nslots' number of
* contiguous buffers, we allocate the buffers from that slot
* and mark the entries as '0' indicating unavailable.
*/
if (!iommu_is_span_boundary(index, nslots,
nr_slots(tbl_dma_addr),
max_slots)) {
if (io_tlb_list[index] >= nslots)
goto found;
}
index = wrap_index(index + stride);
} while (index != wrap);
not_found:
spin_unlock_irqrestore(&io_tlb_lock, flags);
return -1;
found:
for (i = index; i < index + nslots; i++)
io_tlb_list[i] = 0;
for (i = index - 1;
io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&
io_tlb_list[i]; i--)
io_tlb_list[i] = ++count;
/*
* Update the indices to avoid searching in the next round.
*/
if (index + nslots < io_tlb_nslabs)
io_tlb_index = index + nslots;
else
io_tlb_index = 0;
io_tlb_used += nslots;
spin_unlock_irqrestore(&io_tlb_lock, flags);
return index;
}
phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr,
size_t mapping_size, size_t alloc_size,
enum dma_data_direction dir, unsigned long attrs)
{
unsigned int index, i;
dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(hwdev, io_tlb_start);
unsigned long flags;
phys_addr_t tlb_addr;
unsigned int nslots, stride, index, wrap;
int i;
unsigned long mask;
unsigned long offset_slots;
unsigned long max_slots;
unsigned long tmp_io_tlb_used;
if (no_iotlb_memory)
panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
@ -553,32 +473,113 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
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)",
dev_warn_once(hwdev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)",
mapping_size, alloc_size);
return (phys_addr_t)DMA_MAPPING_ERROR;
}
index = find_slots(dev, alloc_size);
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, io_tlb_nslabs, io_tlb_used);
return (phys_addr_t)DMA_MAPPING_ERROR;
}
mask = dma_get_seg_boundary(hwdev);
tbl_dma_addr &= mask;
offset_slots = nr_slots(tbl_dma_addr);
/*
* Carefully handle integer overflow which can occur when mask == ~0UL.
*/
max_slots = mask + 1
? nr_slots(mask + 1)
: 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
/*
* For mappings greater than or equal to a page, we limit the stride
* (and hence alignment) to a page size.
*/
nslots = nr_slots(alloc_size);
if (alloc_size >= PAGE_SIZE)
stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
else
stride = 1;
BUG_ON(!nslots);
/*
* Find suitable number of IO TLB entries size that will fit this
* request and allocate a buffer from that IO TLB pool.
*/
spin_lock_irqsave(&io_tlb_lock, flags);
if (unlikely(nslots > io_tlb_nslabs - io_tlb_used))
goto not_found;
index = ALIGN(io_tlb_index, stride);
if (index >= io_tlb_nslabs)
index = 0;
wrap = index;
do {
while (iommu_is_span_boundary(index, nslots, offset_slots,
max_slots)) {
index += stride;
if (index >= io_tlb_nslabs)
index = 0;
if (index == wrap)
goto not_found;
}
/*
* If we find a slot that indicates we have 'nslots' number of
* contiguous buffers, we allocate the buffers from that slot
* and mark the entries as '0' indicating unavailable.
*/
if (io_tlb_list[index] >= nslots) {
int count = 0;
for (i = index; i < (int) (index + nslots); i++)
io_tlb_list[i] = 0;
for (i = index - 1;
io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&
io_tlb_list[i]; i--)
io_tlb_list[i] = ++count;
tlb_addr = io_tlb_start + (index << IO_TLB_SHIFT);
/*
* Update the indices to avoid searching in the next
* round.
*/
io_tlb_index = ((index + nslots) < io_tlb_nslabs
? (index + nslots) : 0);
goto found;
}
index += stride;
if (index >= io_tlb_nslabs)
index = 0;
} while (index != wrap);
not_found:
tmp_io_tlb_used = io_tlb_used;
spin_unlock_irqrestore(&io_tlb_lock, flags);
if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n",
alloc_size, io_tlb_nslabs, tmp_io_tlb_used);
return (phys_addr_t)DMA_MAPPING_ERROR;
found:
io_tlb_used += nslots;
spin_unlock_irqrestore(&io_tlb_lock, flags);
/*
* 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
* needed.
*/
for (i = 0; i < nr_slots(alloc_size); i++)
io_tlb_orig_addr[index + i] = slot_addr(orig_addr, i);
tlb_addr = slot_addr(io_tlb_start, index);
for (i = 0; i < nslots; i++)
io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT);
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);
return tlb_addr;
}