[v8,0/1] Switchtec Switch DMA Engine Driver

Message

Kelvin Cao March 18, 2024, 4:33 p.m. UTC

Hi,
 
This is v8 of the Switchtec Switch DMA Engine Driver, incorporating
changes for the v2/v3/v4/v5/v6 review comments. This version is same as
v7 except some newly added Gen5 device IDs.

v8 changes:
  - Rebase onto kernel 6.8
  - Add Gen5 device IDs
 
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 6.8.

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 | 1546 +++++++++++++++++++++++++++++++++++
 4 files changed, 1562 insertions(+)
 create mode 100644 drivers/dma/switchtec_dma.c