It is unnecessary to call spin_lock_bh() if you are already in a tasklet.

Signed-off-by: Yunbo Yu <yuyunbo519@gmail.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/20220418142021.1241558-1-yuyunbo519@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

The wrappers in include/linux/pci-dma-compat.h should go away.

pci_set_dma_mask()/pci_set_consistent_dma_mask() should be
replaced with dma_set_mask()/dma_set_coherent_mask(),
and use dma_set_mask_and_coherent() for both.

Signed-off-by: Qing Wang <wangqing@vivo.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/1633663733-47199-7-git-send-email-wangqing@vivo.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Add a missing put_device(&pdev->dev) if the call to
dma_async_device_register(dma); fails.

Fixes: 905ca51e63be ("dmaengine: plx-dma: Introduce PLX DMA engine PCI driver skeleton")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/YFnq/0IQzixtAbC1@mwanda
Signed-off-by: Vinod Koul <vkoul@kernel.org>

In preparation for unconditionally passing the
struct tasklet_struct pointer to all tasklet
callbacks, switch to using the new tasklet_setup()
and from_tasklet() to pass the tasklet pointer explicitly.

Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Link: https://lore.kernel.org/r/20200831103542.305571-34-allen.lkml@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

On prep, a spin lock is taken and the next entry in the circular buffer
is filled. On submit, the valid bit is set in the hardware descriptor
and the lock is released.

The DMA engine is started (if it's not already running) when the client
calls dma_async_issue_pending().

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/20200103212021.2881-4-logang@deltatee.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Allocate DMA coherent memory for the ring of DMA descriptors and
program the appropriate hardware registers.

A tasklet is created which is triggered on an interrupt to process
all the finished requests. Additionally, any remaining descriptors
are aborted when the hardware is removed or the resources freed.

Use an RCU pointer to synchronize PCI device unbind.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/20200103212021.2881-3-logang@deltatee.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Some PLX Switches can expose DMA engines via extra PCI functions
on the upstream port. Each function will have one DMA channel.

This patch is just the core PCI driver skeleton and dma
engine registration.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/20200103212021.2881-2-logang@deltatee.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>