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Subject: Re: [PATCH V3 XRT Alveo 13/18] fpga: xrt: devctl platform driver
To:     Lizhi Hou <lizhi.hou@xilinx.com>, linux-kernel@vger.kernel.org
Cc:     linux-fpga@vger.kernel.org, maxz@xilinx.com,
        sonal.santan@xilinx.com, michal.simek@xilinx.com,
        stefanos@xilinx.com, devicetree@vger.kernel.org, mdf@kernel.org,
        robh@kernel.org, Max Zhen <max.zhen@xilinx.com>
References: <20210218064019.29189-1-lizhih@xilinx.com>
 <20210218064019.29189-14-lizhih@xilinx.com>
 <f32d06bc-1054-eb97-cce1-9b40e9c4442b@redhat.com>
 <20b2a60e-1ed1-c466-ce0b-26179338390e@xilinx.com>
From:   Tom Rix <trix@redhat.com>
Message-ID: <1c0b59ac-400a-aac6-9886-6b6e7c685a9c@redhat.com>
Date:   Wed, 17 Mar 2021 14:16:39 -0700
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On 3/16/21 4:54 PM, Lizhi Hou wrote:
>
>
> On 03/04/2021 05:39 AM, Tom Rix wrote:
>> CAUTION: This message has originated from an External Source. Please use proper judgment and caution when opening attachments, clicking links, or responding to this email.
>>
>>
>> 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
> Sure.
>>> +     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 ?
> Not sure if I understand the question correctly. ddr_calib will have more things need to handle other than just read/write.

I do not understand either, ignore this comment.

If it is important, I will bring it up in a later revision's review and do a better job of explaining the issue.

Tom

>>> +};
>>> +
>>> +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 ?
> Will change to 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 ?
> change xgir_id to u32.
>>> +
>>> +             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 ?
> Will remove write msg from this patch set and add it back in future patches.
>
> Thanks,
> Lizhi
>>
>> 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);
>>> +}
>