crypto: qat - fix DMA transfer direction

In the Linux kernel, the following vulnerability has been resolved:

crypto: qat - fix DMA transfer direction

When CONFIG_DMA_API_DEBUG is selected, while running the crypto self

test on the QAT crypto algorithms, the function add_dma_entry() reports

a warning similar to the one below, saying that overlapping mappings

are not supported. This occurs in tests where the input and the output

scatter list point to the same buffers (i.e. two different scatter lists

which point to the same chunks of memory).

The logic that implements the mapping uses the flag DMA_BIDIRECTIONAL

for both the input and the output scatter lists which leads to

overlapped write mappings. These are not supported by the DMA layer.

Fix by specifying the correct DMA transfer directions when mapping

buffers. For in-place operations where the input scatter list

matches the output scatter list, buffers are mapped once with

DMA_BIDIRECTIONAL, otherwise input buffers are mapped using the flag

DMA_TO_DEVICE and output buffers are mapped with DMA_FROM_DEVICE.

Overlapping a read mapping with a write mapping is a valid case in

dma-coherent devices like QAT.

The function that frees and unmaps the buffers, qat_alg_free_bufl()

has been changed accordingly to the changes to the mapping function.

DMA-API: 4xxx 0000:06:00.0: cacheline tracking EEXIST, overlapping mappings aren't supported

WARNING: CPU: 53 PID: 4362 at kernel/dma/debug.c:570 add_dma_entry+0x1e9/0x270

...

Call Trace:

dma_map_page_attrs+0x82/0x2d0

? preempt_count_add+0x6a/0xa0

qat_alg_sgl_to_bufl+0x45b/0x990 [intel_qat]

qat_alg_aead_dec+0x71/0x250 [intel_qat]

crypto_aead_decrypt+0x3d/0x70

test_aead_vec_cfg+0x649/0x810

? number+0x310/0x3a0

? vsnprintf+0x2a3/0x550

? scnprintf+0x42/0x70

? valid_sg_divisions.constprop.0+0x86/0xa0

? test_aead_vec+0xdf/0x120

test_aead_vec+0xdf/0x120

alg_test_aead+0x185/0x400

alg_test+0x3d8/0x500

? crypto_acomp_scomp_free_ctx+0x30/0x30

? __schedule+0x32a/0x12a0

? ttwu_queue_wakelist+0xbf/0x110

? _raw_spin_unlock_irqrestore+0x23/0x40

? try_to_wake_up+0x83/0x570

? _raw_spin_unlock_irqrestore+0x23/0x40

? __set_cpus_allowed_ptr_locked+0xea/0x1b0

? crypto_acomp_scomp_free_ctx+0x30/0x30

cryptomgr_test+0x27/0x50

kthread+0xe6/0x110

? kthread_complete_and_exit+0x20/0x20

ret_from_fork+0x1f/0x30