[PATCH v7 0/1] Switchtec Switch DMA Engine Driver

From: Kelvin Cao
Date: Wed Oct 11 2023 - 19:19:32 EST


Hi,

This is v7 of the Switchtec Switch DMA Engine Driver, incorporating
changes for the v2/v3/v4/v5/v6 review comments.

v7 changes:
- Remove implementation of device_prep_dma_imm_data

v6 changes:
- Fix './scripts/checkpatch.pl --strict' warnings
- Use readl_poll_timeout_atomic for status checking with timeout
- Wrap enable_channel/disable_channel over channel_op
- Use flag GFP_NOWAIT for mem allocation in switchtec_dma_alloc_desc
- Use proper comment for macro SWITCHTEC_DMA_DEVICE

v5 changes:
- Remove unnecessary structure modifier '__packed'
- Remove the use of union of identical data types in a structure
- Remove unnecessary call sites of synchronize_irq
- Remove unnecessary rcu lock for pdev during device initialization
- Use pci_request_irq/pci_free_irq to replace request_irq/free_irq
- Add mailing list info in file MAINTAINERS
- Miscellaneous cleanups

v4 changes:
- Sort driver entry in drivers/dma/Kconfig and drivers/dma/Makefile
alphabetically
- Fix miscellaneous style issues
- Correct year in copyright
- Add function and call sites to flush PCIe MMIO Write
- Add a helper to wait for status register update
- Move synchronize_irq out of RCU critical section
- Remove unnecessary endianness conversion for register access
- Remove some unused code
- Use pci_enable_device/pci_request_mem_regions instead of
pcim_enable_device/pcim_iomap_regions to make the resource lifetime
management more understandable
- Use offset macros instead of memory mapped structures when accessing
some registers
- Remove the attempt to set DMA mask with smaller number as it would
never succeed if the first attempt with bigger number fails
- Use PCI_VENDOR_ID_MICROSEMI in include/linux/pci_ids.h as device ID

v3 changes:
- Remove some unnecessary memory/variable zeroing

v2 changes:
- Move put_device(dma_dev->dev) before kfree(swdma_dev) as dma_dev is
part of swdma_dev.
- Convert dev_ print calls to pci_ print calls to make the use of
print functions consistent within switchtec_dma_create().
- Remove some dev_ print calls, which use device pointer as handles,
to ensure there's no reference issue when the device is unbound.
- Remove unused .driver_data from pci_device_id structure.

v1:
The following patch implements a DMAEngine driver to use the DMA
controller in Switchtec PSX/PFX switchtes. The DMA controller appears as
a PCI function on the switch upstream port. The DMA function can include
one or more DMA channels.

This patchset is based off of 6.6.0-rc5.

Kelvin Cao (1):
dmaengine: switchtec-dma: Introduce Switchtec DMA engine PCI driver

MAINTAINERS | 6 +
drivers/dma/Kconfig | 9 +
drivers/dma/Makefile | 1 +
drivers/dma/switchtec_dma.c | 1522 +++++++++++++++++++++++++++++++++++
4 files changed, 1538 insertions(+)
create mode 100644 drivers/dma/switchtec_dma.c

--
2.25.1