dma-mapping: benchmark: remove MODULE_LICENSE in non-modules

Since commit 8b41fc4454e ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations
are used to identify modules. As a consequence, uses of the macro
in non-modules will cause modprobe to misidentify their containing
object file as a module when it is not (false positives), and modprobe
might succeed rather than failing with a suitable error message.

So remove it in the files in this commit, none of which can be built as
modules.

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: linux-modules@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: iommu@lists.linux.dev
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

dma-mapping: benchmark: extract a common header file for map_benchmark definition

kernel/dma/map_benchmark.c and selftests/dma/dma_map_benchmark.c
have duplicate map_benchmark definitions, which tends to lead to
inconsistent changes to map_benchmark on both sides, extract a
common header file to avoid this problem.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Acked-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

dma-mapping: benchmark: Add support for multi-pages map/unmap

Currently it only support one page map/unmap once a time for dma-map
benchmark, but there are some other scenaries which need to support for
multi-page map/unmap: for those multi-pages interfaces such as
dma_alloc_coherent() and dma_map_sg(), the time spent on multi-pages
map/unmap is not the time of a single page * npages (not linear) as it
may use block description instead of page description when it is satified
with the size such as 2M/1G, and also it can send a single TLB invalidation
command to invalidate multi-pages instead of multi-times when RIL is
enabled (which will short the time of unmap). So it is necessary to add
support for multi-pages map/unmap.

Add a parameter "-g" to support multi-pages map/unmap.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Acked-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

dma-mapping: benchmark: use the correct HiSilicon copyright

s/Hisilicon/HiSilicon/g.
It should use capital S, according to
https://www.hisilicon.com/en/terms-of-use.

Signed-off-by: Hao Fang <fanghao11@huawei.com>
Acked-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

dma-mapping: benchmark: pretend DMA is transmitting

In a real dma mapping user case, after dma_map is done, data will be
transmit. Thus, in multi-threaded user scenario, IOMMU contention
should not be that severe. For example, if users enable multiple
threads to send network packets through 1G/10G/100Gbps NIC, usually
the steps will be: map -> transmission -> unmap. Transmission delay
reduces the contention of IOMMU.

Here a delay is added to simulate the transmission between map and unmap
so that the tested result could be more accurate for TX and simple RX.
A typical TX transmission for NIC would be like: map -> TX -> unmap
since the socket buffers come from OS. Simple RX model eg. disk driver,
is also map -> RX -> unmap, but real RX model in a NIC could be more
complicated considering packets can come spontaneously and many drivers
are using pre-mapped buffers pool. This is in the TBD list.

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

dma-mapping: benchmark: use u8 for reserved field in uAPI structure

The original code put five u32 before a u64 expansion[10] array. Five is
odd, this will cause trouble in the extension of the structure by adding
new features. This patch moves to use u8 for reserved field to avoid
future alignment risk.
Meanwhile, it also clears the memory of struct map_benchmark in tools,
otherwise, if users use old version to run on newer kernel, the random
expansion value will cause side effect on newer kernel.

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

dma-mapping: benchmark: fix kernel crash when dma_map_single fails

if dma_map_single() fails, kernel will give the below oops since
task_struct has been destroyed and we are running into the memory
corruption due to use-after-free in kthread_stop():

[ 48.095310] Unable to handle kernel paging request at virtual address 000000c473548040
[ 48.095736] Mem abort info:
[ 48.095864] ESR = 0x96000004
[ 48.096025] EC = 0x25: DABT (current EL), IL = 32 bits
[ 48.096268] SET = 0, FnV = 0
[ 48.096401] EA = 0, S1PTW = 0
[ 48.096538] Data abort info:
[ 48.096659] ISV = 0, ISS = 0x00000004
[ 48.096820] CM = 0, WnR = 0
[ 48.097079] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000104639000
[ 48.098099] [000000c473548040] pgd=0000000000000000, p4d=0000000000000000
[ 48.098832] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[ 48.099232] Modules linked in:
[ 48.099387] CPU: 0 PID: 2 Comm: kthreadd Tainted: G W
[ 48.099887] Hardware name: linux,dummy-virt (DT)
[ 48.100078] pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--)
[ 48.100516] pc : __kmalloc_node+0x214/0x368
[ 48.100944] lr : __kmalloc_node+0x1f4/0x368
[ 48.101458] sp : ffff800011f0bb80
[ 48.101843] x29: ffff800011f0bb80 x28: ffff0000c0098ec0
[ 48.102330] x27: 0000000000000000 x26: 00000000001d4600
[ 48.102648] x25: ffff0000c0098ec0 x24: ffff800011b6a000
[ 48.102988] x23: 00000000ffffffff x22: ffff0000c0098ec0
[ 48.103333] x21: ffff8000101d7a54 x20: 0000000000000dc0
[ 48.103657] x19: ffff0000c0001e00 x18: 0000000000000000
[ 48.104069] x17: 0000000000000000 x16: 0000000000000000
[ 48.105449] x15: 000001aa0304e7b9 x14: 00000000000003b1
[ 48.106401] x13: ffff8000122d5000 x12: ffff80001228d000
[ 48.107296] x11: ffff0000c0154340 x10: 0000000000000000
[ 48.107862] x9 : ffff80000fffffff x8 : ffff0000c473527f
[ 48.108326] x7 : ffff800011e62f58 x6 : ffff0000c01c8ed8
[ 48.108778] x5 : ffff0000c0098ec0 x4 : 0000000000000000
[ 48.109223] x3 : 00000000001d4600 x2 : 0000000000000040
[ 48.109656] x1 : 0000000000000001 x0 : ff0000c473548000
[ 48.110104] Call trace:
[ 48.110287] __kmalloc_node+0x214/0x368
[ 48.110493] __vmalloc_node_range+0xc4/0x298
[ 48.110805] copy_process+0x2c8/0x15c8
[ 48.111133] kernel_clone+0x5c/0x3c0
[ 48.111373] kernel_thread+0x64/0x90
[ 48.111604] kthreadd+0x158/0x368
[ 48.111810] ret_from_fork+0x10/0x30
[ 48.112336] Code: 17ffffe9 b9402a62 b94008a1 11000421 (f8626802)
[ 48.112884] ---[ end trace d4890e21e75419d5 ]---

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

dma-mapping: add benchmark support for streaming DMA APIs

Nowadays, there are increasing requirements to benchmark the performance
of dma_map and dma_unmap particually while the device is attached to an
IOMMU.

This patch enables the support. Users can run specified number of threads
to do dma_map_page and dma_unmap_page on a specific NUMA node with the
specified duration. Then dma_map_benchmark will calculate the average
latency for map and unmap.

A difficulity for this benchmark is that dma_map/unmap APIs must run on
a particular device. Each device might have different backend of IOMMU or
non-IOMMU.

So we use the driver_override to bind dma_map_benchmark to a particual
device by:
For platform devices:
echo dma_map_benchmark > /sys/bus/platform/devices/xxx/driver_override
echo xxx > /sys/bus/platform/drivers/xxx/unbind
echo xxx > /sys/bus/platform/drivers/dma_map_benchmark/bind

For PCI devices:
echo dma_map_benchmark > /sys/bus/pci/devices/0000:00:01.0/driver_override
echo 0000:00:01.0 > /sys/bus/pci/drivers/xxx/unbind
echo 0000:00:01.0 > /sys/bus/pci/drivers/dma_map_benchmark/bind

Cc: Will Deacon <will@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
[hch: folded in two fixes from Colin Ian King <colin.king@canonical.com>]
Signed-off-by: Christoph Hellwig <hch@lst.de>