dmatest measures around 30 MB/s for one ptdma channel in EPYC 7302p and 11 GB/s for ioatdma channel in Xeon Gold 6248. Is it a driver limitation? I run dmatest as modprobe dmatest timeout=10000 transfer_size=512 test_buf_size=1048576 threads_per_chan=1 iterations=1000 run=1 wait=1 On Tue, Jan 21, 2020 at 4:06 AM Sanjay R Mehta <Sanju.Mehta@xxxxxxx> wrote: > > From: Sanjay R Mehta <sanju.mehta@xxxxxxx> > > This patch series adds support for AMD PassThru DMA Engine which > performs high bandwidth memory-to-memory and IO copy operation and > performs DMA transfer through queue based descriptor management. > > AMD Processor has multiple ptdma device instances and each engine has > single queue. The driver also adds support for for multiple PTDMA > instances, each device will get an unique identifier and uniquely > named resources. > > v3: > - Fixed the sparse warnings. > > v2: > - Added controller description in cover letter > - Removed "default m" from Kconfig > - Replaced low_address() and high_address() functions with kernel > API's lower_32_bits & upper_32_bits(). > - Removed the BH handler function pt_core_irq_bh() and instead > handling transaction in irq handler itself. > - Moved presetting of command queue registers into new function > "init_cmdq_regs()" > - Removed the kernel thread dependency to submit transaction. > - Increased the hardware command queue size to 32 and adding it > as a module parameter. > - Removed backlog command queue handling mechanism. > - Removed software command queue handling and instead submitting > transaction command directly to > hardware command queue. > - Added tasklet structure variable in "struct pt_device". > This is used to invoke pt_do_cmd_complete() upon receiving interrupt > for command completion. > - pt_core_perform_passthru() function parameters are modified and it is > now used to submit command directly to hardware from dmaengine framework. > - Removed below structures, enums, macros and functions, as these values are > constants. Making command submission simple, > - Removed "union pt_function" and several macros like PT_VERSION, > PT_BYTESWAP, PT_CMD_* etc.. > - enum pt_passthru_bitwise, enum pt_passthru_byteswap, enum pt_memtype > struct pt_dma_info, struct pt_data, struct pt_mem, struct pt_passthru_op, > struct pt_op, > - Removed functions -> pt_cmd_queue_thread() pt_run_passthru_cmd(), > pt_run_cmd(), pt_dev_init(), pt_dequeue_cmd(), pt_do_cmd_backlog(), > pt_enqueue_cmd(), > - Below functions, stuctures and variables moved from ptdma-ops.c > - Moved function pt_alloc_struct() to ptdma-pci.c as its used only there. > - Moved "struct pt_tasklet_data" structure to ptdma.h > - Moved functions pt_do_cmd_complete(), pt_present(), pt_get_device(), > pt_add_device(), pt_del_device(), pt_log_error() and its dependent > static variables pt_unit_lock, pt_units, pt_rr_lock, pt_rr, pt_error_codes, > pt_ordinal to ptdma-dev.c as they are used only in that file. > > Links of the review comments for v2: > 1. https://lkml.org/lkml/2019/12/27/630 > 2. https://lkml.org/lkml/2020/1/3/23 > 3. https://lkml.org/lkml/2020/1/3/314 > 4. https://lkml.org/lkml/2020/1/10/100 > > > Links of the review comments for v1: > > 1. https://lkml.org/lkml/2019/9/24/490 > 2. https://lkml.org/lkml/2019/9/24/399 > 3. https://lkml.org/lkml/2019/9/24/862 > 4. https://lkml.org/lkml/2019/9/24/122 > > Sanjay R Mehta (3): > dmaengine: ptdma: Initial driver for the AMD PassThru DMA engine > dmaengine: ptdma: Register pass-through engine as a DMA resource > dmaengine: ptdma: Add debugfs entries for PTDMA information > > MAINTAINERS | 6 + > drivers/dma/Kconfig | 2 + > drivers/dma/Makefile | 1 + > drivers/dma/ptdma/Kconfig | 7 + > drivers/dma/ptdma/Makefile | 12 + > drivers/dma/ptdma/ptdma-debugfs.c | 237 ++++++++++++ > drivers/dma/ptdma/ptdma-dev.c | 448 +++++++++++++++++++++++ > drivers/dma/ptdma/ptdma-dmaengine.c | 704 ++++++++++++++++++++++++++++++++++++ > drivers/dma/ptdma/ptdma-pci.c | 269 ++++++++++++++ > drivers/dma/ptdma/ptdma.h | 378 +++++++++++++++++++ > 10 files changed, 2064 insertions(+) > create mode 100644 drivers/dma/ptdma/Kconfig > create mode 100644 drivers/dma/ptdma/Makefile > create mode 100644 drivers/dma/ptdma/ptdma-debugfs.c > create mode 100644 drivers/dma/ptdma/ptdma-dev.c > create mode 100644 drivers/dma/ptdma/ptdma-dmaengine.c > create mode 100644 drivers/dma/ptdma/ptdma-pci.c > create mode 100644 drivers/dma/ptdma/ptdma.h > > -- > 2.7.4 > -- wbr, Vitaly
