Re: [PATCH V3 XRT Alveo 13/18] fpga: xrt: devctl platform driver

Tom Rix
2021-03-04T13:42:26Z

On 2/17/21 10:40 PM, Lizhi Hou wrote:
> Add devctl driver. devctl is a type of hardware function which only has
> few registers to read or write. They are discovered by walking firmware
> metadata. A platform device node will be created for them.
>
> Signed-off-by: Sonal Santan <sonal.santan@xilinx.com>
> Signed-off-by: Max Zhen <max.zhen@xilinx.com>
> Signed-off-by: Lizhi Hou <lizhih@xilinx.com>
> ---
> drivers/fpga/xrt/include/xleaf/devctl.h | 43 +++++
> drivers/fpga/xrt/lib/xleaf/devctl.c | 206 ++++++++++++++++++++++++
> 2 files changed, 249 insertions(+)
> create mode 100644 drivers/fpga/xrt/include/xleaf/devctl.h
> create mode 100644 drivers/fpga/xrt/lib/xleaf/devctl.c
>
> diff --git a/drivers/fpga/xrt/include/xleaf/devctl.h b/drivers/fpga/xrt/include/xleaf/devctl.h
> new file mode 100644
> index 000000000000..96a40e066f83
> --- /dev/null
> +++ b/drivers/fpga/xrt/include/xleaf/devctl.h
> @@ -0,0 +1,43 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Header file for XRT DEVCTL Leaf Driver
> + *
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + * Lizhi Hou <Lizhi.Hou@xilinx.com>
> + */
> +
> +#ifndef _XRT_DEVCTL_H_
> +#define _XRT_DEVCTL_H_
> +
> +#include "xleaf.h"
> +
> +/*
> + * DEVCTL driver IOCTL calls.
> + */
> +enum xrt_devctl_ioctl_cmd {
> + XRT_DEVCTL_READ = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
> + XRT_DEVCTL_WRITE,
> +};
> +
> +enum xrt_devctl_id {
> + XRT_DEVCTL_ROM_UUID,
Assumes 0, should make this explicit and initialize to 0
> + XRT_DEVCTL_DDR_CALIB,
> + XRT_DEVCTL_GOLDEN_VER,
> + XRT_DEVCTL_MAX
> +};
> +
> +struct xrt_devctl_ioctl_rw {
> + u32 xgir_id;
> + void *xgir_buf;
> + u32 xgir_len;
> + u32 xgir_offset;
similar to other patches, the xgir_ prefix is not needed
> +};
> +
> +struct xrt_devctl_ioctl_intf_uuid {
> + u32 xgir_uuid_num;
> + uuid_t *xgir_uuids;
> +};
> +
> +#endif /* _XRT_DEVCTL_H_ */
> diff --git a/drivers/fpga/xrt/lib/xleaf/devctl.c b/drivers/fpga/xrt/lib/xleaf/devctl.c
> new file mode 100644
> index 000000000000..caf8c6569f0f
> --- /dev/null
> +++ b/drivers/fpga/xrt/lib/xleaf/devctl.c
> @@ -0,0 +1,206 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Xilinx Alveo FPGA devctl Driver
> + *
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + * Lizhi Hou<Lizhi.Hou@xilinx.com>
> + */
> +
> +#include <linux/mod_devicetable.h>
> +#include <linux/platform_device.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include "metadata.h"
> +#include "xleaf.h"
> +#include "xleaf/devctl.h"
> +
> +#define XRT_DEVCTL "xrt_devctl"
> +
> +struct xrt_name_id {
> + char *ep_name;
> + int id;
> +};
> +
> +static struct xrt_name_id name_id[XRT_DEVCTL_MAX] = {
> + { XRT_MD_NODE_BLP_ROM, XRT_DEVCTL_ROM_UUID },
> + { XRT_MD_NODE_GOLDEN_VER, XRT_DEVCTL_GOLDEN_VER },
DDR_CALIB is unused ?
> +};
> +
> +struct xrt_devctl {
> + struct platform_device *pdev;
> + void __iomem *base_addrs[XRT_DEVCTL_MAX];
> + ulong sizes[XRT_DEVCTL_MAX];
> +};
similar to other patches, why not use regmap ?
> +
> +static int xrt_devctl_name2id(struct xrt_devctl *devctl, const char *name)
> +{
> + int i;
> +
> + for (i = 0; i < XRT_DEVCTL_MAX && name_id[i].ep_name; i++) {
> + if (!strncmp(name_id[i].ep_name, name, strlen(name_id[i].ep_name) + 1))
> + return name_id[i].id;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int
> +xrt_devctl_leaf_ioctl(struct platform_device *pdev, u32 cmd, void *arg)
> +{
> + struct xrt_devctl *devctl;
> + int ret = 0;
> +
> + devctl = platform_get_drvdata(pdev);
> +
> + switch (cmd) {
> + case XRT_XLEAF_EVENT:
> + /* Does not handle any event. */
> + break;
> + case XRT_DEVCTL_READ: {
> + struct xrt_devctl_ioctl_rw *rw_arg = arg;
> + u32 *p_src, *p_dst, i;
> +
> + if (rw_arg->xgir_len & 0x3) {
> + xrt_err(pdev, "invalid len %d", rw_arg->xgir_len);
> + return -EINVAL;
> + }
> +
> + if (rw_arg->xgir_id >= XRT_DEVCTL_MAX) {
> + xrt_err(pdev, "invalid id %d", rw_arg->xgir_id);
> + return -EINVAL;
> + }
needs a < 0 check ?
> +
> + p_src = devctl->base_addrs[rw_arg->xgir_id];
> + if (!p_src) {
> + xrt_err(pdev, "io not found, id %d",
> + rw_arg->xgir_id);
> + return -EINVAL;
> + }
> + if (rw_arg->xgir_offset + rw_arg->xgir_len >
> + devctl->sizes[rw_arg->xgir_id]) {
> + xrt_err(pdev, "invalid argument, off %d, len %d",
> + rw_arg->xgir_offset, rw_arg->xgir_len);
> + return -EINVAL;
> + }
> + p_dst = rw_arg->xgir_buf;
> + for (i = 0; i < rw_arg->xgir_len / sizeof(u32); i++) {
> + u32 val = ioread32(p_src + rw_arg->xgir_offset + i);
> +
> + memcpy(p_dst + i, &val, sizeof(u32));
> + }
> + break;
> + }

The _WRITE msg is not handled Then why have it ?

Tom

> + default:
> + xrt_err(pdev, "unsupported cmd %d", cmd);
> + return -EINVAL;
> + }
> +
> + return ret;
> +}
> +
> +static int xrt_devctl_remove(struct platform_device *pdev)
> +{
> + struct xrt_devctl *devctl;
> + int i;
> +
> + devctl = platform_get_drvdata(pdev);
> +
> + for (i = 0; i < XRT_DEVCTL_MAX; i++) {
> + if (devctl->base_addrs[i])
> + iounmap(devctl->base_addrs[i]);
> + }
> +
> + platform_set_drvdata(pdev, NULL);
> + devm_kfree(&pdev->dev, devctl);
> +
> + return 0;
> +}
> +
> +static int xrt_devctl_probe(struct platform_device *pdev)
> +{
> + struct xrt_devctl *devctl;
> + int i, id, ret = 0;
> + struct resource *res;
> +
> + devctl = devm_kzalloc(&pdev->dev, sizeof(*devctl), GFP_KERNEL);
> + if (!devctl)
> + return -ENOMEM;
> +
> + devctl->pdev = pdev;
> + platform_set_drvdata(pdev, devctl);
> +
> + xrt_info(pdev, "probing...");
> + for (i = 0, res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + res;
> + res = platform_get_resource(pdev, IORESOURCE_MEM, ++i)) {
> + id = xrt_devctl_name2id(devctl, res->name);
> + if (id < 0) {
> + xrt_err(pdev, "ep %s not found", res->name);
> + continue;
> + }
> + devctl->base_addrs[id] = ioremap(res->start, res->end - res->start + 1);
> + if (!devctl->base_addrs[id]) {
> + xrt_err(pdev, "map base failed %pR", res);
> + ret = -EIO;
> + goto failed;
> + }
> + devctl->sizes[id] = res->end - res->start + 1;
> + }
> +
> +failed:
> + if (ret)
> + xrt_devctl_remove(pdev);
> +
> + return ret;
> +}
> +
> +static struct xrt_subdev_endpoints xrt_devctl_endpoints[] = {
> + {
> + .xse_names = (struct xrt_subdev_ep_names[]) {
> + /* add name if ep is in same partition */
> + { .ep_name = XRT_MD_NODE_BLP_ROM },
> + { NULL },
> + },
> + .xse_min_ep = 1,
> + },
> + {
> + .xse_names = (struct xrt_subdev_ep_names[]) {
> + { .ep_name = XRT_MD_NODE_GOLDEN_VER },
> + { NULL },
> + },
> + .xse_min_ep = 1,
> + },
> + /* adding ep bundle generates devctl device instance */
> + { 0 },
> +};
> +
> +static struct xrt_subdev_drvdata xrt_devctl_data = {
> + .xsd_dev_ops = {
> + .xsd_ioctl = xrt_devctl_leaf_ioctl,
> + },
> +};
> +
> +static const struct platform_device_id xrt_devctl_table[] = {
> + { XRT_DEVCTL, (kernel_ulong_t)&xrt_devctl_data },
> + { },
> +};
> +
> +static struct platform_driver xrt_devctl_driver = {
> + .driver = {
> + .name = XRT_DEVCTL,
> + },
> + .probe = xrt_devctl_probe,
> + .remove = xrt_devctl_remove,
> + .id_table = xrt_devctl_table,
> +};
> +
> +void devctl_leaf_init_fini(bool init)
> +{
> + if (init)
> + xleaf_register_driver(XRT_SUBDEV_DEVCTL, &xrt_devctl_driver, xrt_devctl_endpoints);
> + else
> + xleaf_unregister_driver(XRT_SUBDEV_DEVCTL);
> +}