Re: [PATCH v2 3/5] dmaengine: zynqmp_ps_pcie: Adding PS PCIe DMA driver

From: Michal Simek
Date: Wed Sep 20 2017 - 01:49:38 EST


On 8.9.2017 14:23, Ravi Shankar Jonnalagadda wrote:
> Adding support for ZynqmMP PS PCIe EP driver.
> Adding support for ZynqmMP PS PCIe Root DMA driver.
> Modifying Kconfig and Makefile to add the support.
>
> Signed-off-by: Ravi Shankar Jonnalagadda <vjonnal@xxxxxxxxxx>
> Signed-off-by: RaviKiran Gummaluri <rgummal@xxxxxxxxxx>
> ---
> drivers/dma/Kconfig | 12 +++
> drivers/dma/xilinx/Makefile | 2 +
> drivers/dma/xilinx/ps_pcie.h | 44 +++++++++
> drivers/dma/xilinx/ps_pcie_main.c | 200 ++++++++++++++++++++++++++++++++++++++
> include/linux/dma/ps_pcie_dma.h | 69 +++++++++++++
> 5 files changed, 327 insertions(+)
> create mode 100644 drivers/dma/xilinx/ps_pcie.h
> create mode 100644 drivers/dma/xilinx/ps_pcie_main.c
> create mode 100644 include/linux/dma/ps_pcie_dma.h
>
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index fa8f9c0..e2fe4e5 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -586,6 +586,18 @@ config XILINX_ZYNQMP_DMA
> help
> Enable support for Xilinx ZynqMP DMA controller.
>
> +config XILINX_PS_PCIE_DMA
> + tristate "Xilinx PS PCIe DMA support"
> + depends on (PCI && X86_64 || ARM64)
> + select DMA_ENGINE
> + help
> + Enable support for the Xilinx PS PCIe DMA engine present
> + in recent Xilinx ZynqMP chipsets.
> +
> + Say Y here if you have such a chipset.
> +
> + If unsure, say N.
> +
> config ZX_DMA
> tristate "ZTE ZX DMA support"
> depends on ARCH_ZX || COMPILE_TEST
> diff --git a/drivers/dma/xilinx/Makefile b/drivers/dma/xilinx/Makefile
> index 9e91f8f..04f6f99 100644
> --- a/drivers/dma/xilinx/Makefile
> +++ b/drivers/dma/xilinx/Makefile
> @@ -1,2 +1,4 @@
> obj-$(CONFIG_XILINX_DMA) += xilinx_dma.o
> obj-$(CONFIG_XILINX_ZYNQMP_DMA) += zynqmp_dma.o
> +ps_pcie_dma-objs := ps_pcie_main.o ps_pcie_platform.o
> +obj-$(CONFIG_XILINX_PS_PCIE_DMA) += ps_pcie_dma.o
> diff --git a/drivers/dma/xilinx/ps_pcie.h b/drivers/dma/xilinx/ps_pcie.h
> new file mode 100644
> index 0000000..351f051
> --- /dev/null
> +++ b/drivers/dma/xilinx/ps_pcie.h
> @@ -0,0 +1,44 @@
> +/*
> + * Xilinx PS PCIe DMA Engine platform header file
> + *
> + * Copyright (C) 2010-2017 Xilinx, Inc. All rights reserved.
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation
> + */
> +
> +#ifndef __XILINX_PS_PCIE_H
> +#define __XILINX_PS_PCIE_H
> +
> +#include <linux/delay.h>
> +#include <linux/dma-direction.h>

this is included via dma-mapping.h below.

> +#include <linux/dmaengine.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/interrupt.h>
> +#include <linux/ioport.h>
> +#include <linux/irqreturn.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mempool.h>
> +#include <linux/of.h>
> +#include <linux/pci.h>
> +#include <linux/property.h>

this is already include via of.h

> +#include <linux/platform_device.h>
> +#include <linux/timer.h>
> +#include <linux/dma/ps_pcie_dma.h>

Don't we have any script for checking this?

> +
> +/**
> + * dma_platform_driver_register - This will be invoked by module init
> + *
> + * Return: returns status of platform_driver_register
> + */
> +int dma_platform_driver_register(void);


put empty line here.

> +/**
> + * dma_platform_driver_unregister - This will be invoked by module exit
> + *
> + * Return: returns void after unregustering platform driver
> + */
> +void dma_platform_driver_unregister(void);
> +
> +#endif
> diff --git a/drivers/dma/xilinx/ps_pcie_main.c b/drivers/dma/xilinx/ps_pcie_main.c
> new file mode 100644
> index 0000000..4ccd8ef
> --- /dev/null
> +++ b/drivers/dma/xilinx/ps_pcie_main.c
> @@ -0,0 +1,200 @@
> +/*
> + * XILINX PS PCIe driver
> + *
> + * Copyright (C) 2017 Xilinx, Inc. All rights reserved.
> + *
> + * Description
> + * PS PCIe DMA is memory mapped DMA used to execute PS to PL transfers
> + * on ZynqMP UltraScale+ Devices.
> + * This PCIe driver creates a platform device with specific platform
> + * info enabling creation of DMA device corresponding to the channel
> + * information provided in the properties
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation
> + */
> +
> +#include "ps_pcie.h"
> +#include "../dmaengine.h"
> +
> +#define DRV_MODULE_NAME "ps_pcie_dma"
> +
> +static int ps_pcie_dma_probe(struct pci_dev *pdev,
> + const struct pci_device_id *ent);
> +static void ps_pcie_dma_remove(struct pci_dev *pdev);
> +
> +static u32 channel_properties_pcie_axi[] = {
> + (u32)(PCIE_AXI_DIRECTION), (u32)(NUMBER_OF_BUFFER_DESCRIPTORS),
> + (u32)(DEFAULT_DMA_QUEUES), (u32)(CHANNEL_COAELSE_COUNT),
> + (u32)(CHANNEL_POLL_TIMER_FREQUENCY) };
> +
> +static u32 channel_properties_axi_pcie[] = {
> + (u32)(AXI_PCIE_DIRECTION), (u32)(NUMBER_OF_BUFFER_DESCRIPTORS),
> + (u32)(DEFAULT_DMA_QUEUES), (u32)(CHANNEL_COAELSE_COUNT),
> + (u32)(CHANNEL_POLL_TIMER_FREQUENCY) };
> +
> +static struct property_entry generic_pcie_ep_property[] = {
> + PROPERTY_ENTRY_U32("numchannels", (u32)MAX_NUMBER_OF_CHANNELS),
> + PROPERTY_ENTRY_U32_ARRAY("ps_pcie_channel0",
> + channel_properties_pcie_axi),
> + PROPERTY_ENTRY_U32_ARRAY("ps_pcie_channel1",
> + channel_properties_axi_pcie),
> + PROPERTY_ENTRY_U32_ARRAY("ps_pcie_channel2",
> + channel_properties_pcie_axi),
> + PROPERTY_ENTRY_U32_ARRAY("ps_pcie_channel3",
> + channel_properties_axi_pcie),
> + { },
> +};
> +
> +static const struct platform_device_info xlnx_std_platform_dev_info = {
> + .name = XLNX_PLATFORM_DRIVER_NAME,
> + .properties = generic_pcie_ep_property,
> +};
> +
> +/**
> + * ps_pcie_dma_probe - Driver probe function
> + * @pdev: Pointer to the pci_dev structure
> + * @ent: pci device id
> + *
> + * Return: '0' on success and failure value on error
> + */
> +static int ps_pcie_dma_probe(struct pci_dev *pdev,
> + const struct pci_device_id *ent)
> +{
> + int err;
> + struct platform_device *platform_dev;
> + struct platform_device_info platform_dev_info;
> +
> + dev_info(&pdev->dev, "PS PCIe DMA Driver probe\n");
> +
> + err = pcim_enable_device(pdev);
> + if (err) {
> + dev_err(&pdev->dev, "Cannot enable PCI device, aborting\n");
> + return err;
> + }
> +
> + err = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
> + if (err) {
> + dev_info(&pdev->dev, "Cannot set 64 bit DMA mask\n");
> + err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
> + if (err) {
> + dev_err(&pdev->dev, "DMA mask set error\n");
> + return err;
> + }
> + }
> +
> + err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
> + if (err) {
> + dev_info(&pdev->dev, "Cannot set 64 bit consistent DMA mask\n");
> + err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
> + if (err) {
> + dev_err(&pdev->dev, "Cannot set consistent DMA mask\n");
> + return err;
> + }
> + }
> +
> + pci_set_master(pdev);
> +
> + /* For Root DMA platform device will be created through device tree */
> + if (pdev->vendor == PCI_VENDOR_ID_XILINX &&
> + pdev->device == ZYNQMP_RC_DMA_DEVID)
> + return 0;
> +
> + memcpy(&platform_dev_info, &xlnx_std_platform_dev_info,
> + sizeof(xlnx_std_platform_dev_info));
> +
> + /* Do device specific channel configuration changes to
> + * platform_dev_info.properties if required
> + * More information on channel properties can be found
> + * at Documentation/devicetree/bindings/dma/xilinx/ps-pcie-dma.txt
> + */
> +
> + platform_dev_info.parent = &pdev->dev;
> + platform_dev_info.data = &pdev;
> + platform_dev_info.size_data = sizeof(struct pci_dev **);
> +
> + platform_dev = platform_device_register_full(&platform_dev_info);
> + if (IS_ERR(platform_dev)) {
> + dev_err(&pdev->dev,
> + "Cannot create platform device, aborting\n");
> + return PTR_ERR(platform_dev);
> + }
> +
> + pci_set_drvdata(pdev, platform_dev);
> +
> + dev_info(&pdev->dev, "PS PCIe DMA driver successfully probed\n");
> +
> + return 0;
> +}
> +
> +static struct pci_device_id ps_pcie_dma_tbl[] = {
> + { PCI_DEVICE(PCI_VENDOR_ID_XILINX, ZYNQMP_DMA_DEVID) },
> + { PCI_DEVICE(PCI_VENDOR_ID_XILINX, ZYNQMP_RC_DMA_DEVID) },
> + { }
> +};
> +
> +static struct pci_driver ps_pcie_dma_driver = {
> + .name = DRV_MODULE_NAME,
> + .id_table = ps_pcie_dma_tbl,
> + .probe = ps_pcie_dma_probe,
> + .remove = ps_pcie_dma_remove,
> +};
> +
> +/**
> + * ps_pcie_init - Driver init function
> + *
> + * Return: 0 on success. Non zero on failure
> + */
> +static int __init ps_pcie_init(void)
> +{
> + int ret;
> +
> + pr_info("%s init()\n", DRV_MODULE_NAME);
> +
> + ret = pci_register_driver(&ps_pcie_dma_driver);
> + if (ret)
> + return ret;
> +
> + ret = dma_platform_driver_register();
> + if (ret)
> + pci_unregister_driver(&ps_pcie_dma_driver);
> +
> + return ret;
> +}
> +
> +/**
> + * ps_pcie_dma_remove - Driver remove function
> + * @pdev: Pointer to the pci_dev structure
> + *
> + * Return: void
> + */
> +static void ps_pcie_dma_remove(struct pci_dev *pdev)
> +{
> + struct platform_device *platform_dev;
> +
> + platform_dev = (struct platform_device *)pci_get_drvdata(pdev);
> +
> + if (platform_dev)
> + platform_device_unregister(platform_dev);
> +}
> +
> +/**
> + * ps_pcie_exit - Driver exit function
> + *
> + * Return: void
> + */
> +static void __exit ps_pcie_exit(void)
> +{
> + pr_info("%s exit()\n", DRV_MODULE_NAME);
> +
> + dma_platform_driver_unregister();
> + pci_unregister_driver(&ps_pcie_dma_driver);
> +}
> +
> +module_init(ps_pcie_init);
> +module_exit(ps_pcie_exit);
> +
> +MODULE_AUTHOR("Xilinx Inc");
> +MODULE_DESCRIPTION("Xilinx PS PCIe DMA Driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/dma/ps_pcie_dma.h b/include/linux/dma/ps_pcie_dma.h
> new file mode 100644
> index 0000000..d11323a
> --- /dev/null
> +++ b/include/linux/dma/ps_pcie_dma.h
> @@ -0,0 +1,69 @@
> +/*
> + * Xilinx PS PCIe DMA Engine support header file
> + *
> + * Copyright (C) 2017 Xilinx, Inc. All rights reserved.
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation
> + */
> +
> +#ifndef __DMA_XILINX_PS_PCIE_H
> +#define __DMA_XILINX_PS_PCIE_H
> +
> +#include <linux/dma-mapping.h>
> +#include <linux/dmaengine.h>
> +
> +#define XLNX_PLATFORM_DRIVER_NAME "xlnx-platform-dma-driver"
> +
> +#define ZYNQMP_DMA_DEVID (0xD024)
> +#define ZYNQMP_RC_DMA_DEVID (0xD021)


Are these hardcoded? If yes, maybe we have better location where these
should be put.


> +
> +#define MAX_ALLOWED_CHANNELS_IN_HW 4
> +
> +#define MAX_NUMBER_OF_CHANNELS MAX_ALLOWED_CHANNELS_IN_HW
> +
> +#define DEFAULT_DMA_QUEUES 4
> +#define TWO_DMA_QUEUES 2
> +
> +#define NUMBER_OF_BUFFER_DESCRIPTORS 1999
> +#define MAX_DESCRIPTORS 65536
> +
> +#define CHANNEL_COAELSE_COUNT 0
> +
> +#define CHANNEL_POLL_TIMER_FREQUENCY 1000 /* in milli seconds */
> +
> +#define PCIE_AXI_DIRECTION DMA_TO_DEVICE
> +#define AXI_PCIE_DIRECTION DMA_FROM_DEVICE
> +
> +/**
> + * struct BAR_PARAMS - PCIe Bar Parameters
> + * @BAR_PHYS_ADDR: PCIe BAR Physical address
> + * @BAR_LENGTH: Length of PCIe BAR
> + * @BAR_VIRT_ADDR: Virtual Address to access PCIe BAR
> + */
> +struct BAR_PARAMS {
> + dma_addr_t BAR_PHYS_ADDR; /**< Base physical address of BAR memory */
> + unsigned long BAR_LENGTH; /**< Length of BAR memory window */
> + void *BAR_VIRT_ADDR; /**< Virtual Address of mapped BAR memory */
> +};
> +
> +/**
> + * struct ps_pcie_dma_channel_match - Match structure for dma clients
> + * @pci_vendorid: PCIe Vendor id of PS PCIe DMA device
> + * @pci_deviceid: PCIe Device id of PS PCIe DMA device
> + * @board_number: Unique id to identify individual device in a system
> + * @channel_number: Unique channel number of the device
> + * @direction: DMA channel direction
> + * @bar_params: Pointer to BAR_PARAMS for accessing application specific data
> + */
> +struct ps_pcie_dma_channel_match {
> + u16 pci_vendorid;
> + u16 pci_deviceid;
> + u16 board_number;
> + u16 channel_number;
> + enum dma_data_direction direction;
> + struct BAR_PARAMS *bar_params;
> +};
> +
> +#endif
>

Thanks,
Michal


--
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Xilinx Microblaze
Maintainer of Linux kernel - Xilinx Zynq ARM and ZynqMP ARM64 SoCs
U-Boot custodian - Xilinx Microblaze/Zynq/ZynqMP SoCs


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