Re: [PATCH V3 XRT Alveo 10/18] fpga: xrt: VSEC platform driver

Tom Rix
2021-03-02T01:40:24Z

On 2/17/21 10:40 PM, Lizhi Hou wrote:
> Add VSEC driver. VSEC is a hardware function discovered by walking
> PCI Express configure space. A platform device node will be created
> for it. VSEC provides board logic UUID and few offset of other hardware
> functions.
Is this vsec walking infra or is a general find a list of mmio regions that need to be mapped in and do the mapping in as a set of platform drivers ?
> 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/lib/xleaf/vsec.c | 359 ++++++++++++++++++++++++++++++
> 1 file changed, 359 insertions(+)
> create mode 100644 drivers/fpga/xrt/lib/xleaf/vsec.c
>
> diff --git a/drivers/fpga/xrt/lib/xleaf/vsec.c b/drivers/fpga/xrt/lib/xleaf/vsec.c
> new file mode 100644
> index 000000000000..8e5cb22522ec
> --- /dev/null
> +++ b/drivers/fpga/xrt/lib/xleaf/vsec.c
> @@ -0,0 +1,359 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Xilinx Alveo FPGA VSEC Driver
> + *
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + * Lizhi Hou<Lizhi.Hou@xilinx.com>
> + */
> +
> +#include <linux/platform_device.h>
> +#include "metadata.h"
> +#include "xleaf.h"
> +
> +#define XRT_VSEC "xrt_vsec"
> +
> +#define VSEC_TYPE_UUID 0x50
> +#define VSEC_TYPE_FLASH 0x51
> +#define VSEC_TYPE_PLATINFO 0x52
> +#define VSEC_TYPE_MAILBOX 0x53
> +#define VSEC_TYPE_END 0xff
Type of devices, this list can not grow much.
> +
> +#define VSEC_UUID_LEN 16
> +
> +struct xrt_vsec_header {
> + u32 format;
> + u32 length;
> + u32 entry_sz;
> + u32 rsvd;
> +} __packed;
> +
> +#define head_rd(g, r) \
> + ioread32((void *)(g)->base + offsetof(struct xrt_vsec_header, r))
> +
> +#define GET_BAR(entry) (((entry)->bar_rev >> 4) & 0xf)
> +#define GET_BAR_OFF(_entry) \
> + ({ typeof(_entry) entry = (_entry); \
> + ((entry)->off_lo | ((u64)(entry)->off_hi << 16)); })

A 48 bit value stored in xrt_md_endpoint.bar_off (long)

bar_off should be u64

> +#define GET_REV(entry) ((entry)->bar_rev & 0xf)
> +
I prefer functions over macros.
> +struct xrt_vsec_entry {
> + u8 type;
> + u8 bar_rev;
> + u16 off_lo;
> + u32 off_hi;
> + u8 ver_type;
> + u8 minor;
> + u8 major;
> + u8 rsvd0;
> + u32 rsvd1;
> +} __packed;
> +
> +#define read_entry(g, i, e) \
> + do { \
> + u32 *p = (u32 *)((g)->base + \
> + sizeof(struct xrt_vsec_header) + \
> + (i) * sizeof(struct xrt_vsec_entry)); \
> + u32 off; \
> + for (off = 0; \
> + off < sizeof(struct xrt_vsec_entry) / 4; \
> + off++) \
> + *((u32 *)(e) + off) = ioread32(p + off);\
> + } while (0)
This could be a static inline func.
> +
> +struct vsec_device {
> + u8 type;
> + char *ep_name;
> + ulong size;
> + char *regmap;
> +};
> +
> +static struct vsec_device vsec_devs[] = {
> + {
> + .type = VSEC_TYPE_UUID,
> + .ep_name = XRT_MD_NODE_BLP_ROM,
> + .size = VSEC_UUID_LEN,
> + .regmap = "vsec-uuid",
> + },
> + {
> + .type = VSEC_TYPE_FLASH,
> + .ep_name = XRT_MD_NODE_FLASH_VSEC,
> + .size = 4096,
> + .regmap = "vsec-flash",
> + },
> + {
> + .type = VSEC_TYPE_PLATINFO,
> + .ep_name = XRT_MD_NODE_PLAT_INFO,
> + .size = 4,
> + .regmap = "vsec-platinfo",
> + },
> + {
> + .type = VSEC_TYPE_MAILBOX,
> + .ep_name = XRT_MD_NODE_MAILBOX_VSEC,
> + .size = 48,
> + .regmap = "vsec-mbx",
> + },
This is a static list, how would a new type be added to this ?
> +};
> +
> +struct xrt_vsec {
> + struct platform_device *pdev;
> + void *base;
> + ulong length;
> +
> + char *metadata;
> + char uuid[VSEC_UUID_LEN];
> +};
> +
> +static char *type2epname(u32 type)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(vsec_devs); i++) {
> + if (vsec_devs[i].type == type)
> + return (vsec_devs[i].ep_name);
> + }
> +
> + return NULL;
> +}
> +
> +static ulong type2size(u32 type)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(vsec_devs); i++) {
> + if (vsec_devs[i].type == type)
> + return (vsec_devs[i].size);
> + }
> +
> + return 0;
> +}
> +
> +static char *type2regmap(u32 type)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(vsec_devs); i++) {
> + if (vsec_devs[i].type == type)
> + return (vsec_devs[i].regmap);
> + }
> +
> + return NULL;
> +}
> +
> +static int xrt_vsec_add_node(struct xrt_vsec *vsec,
> + void *md_blob, struct xrt_vsec_entry *p_entry)
> +{
> + struct xrt_md_endpoint ep;
> + char regmap_ver[64];
> + int ret;
> +
> + if (!type2epname(p_entry->type))
> + return -EINVAL;
> +
> + /*
> + * VSEC may have more than 1 mailbox instance for the card
> + * which has more than 1 physical function.
> + * This is not supported for now. Assuming only one mailbox
> + */

are multiple uuid types allowed ?

this says assume 1, but logic will recreate 1+

can you check if a mbx ep exists before creating ?

> +
> + snprintf(regmap_ver, sizeof(regmap_ver) - 1, "%d-%d.%d.%d",
> + p_entry->ver_type, p_entry->major, p_entry->minor,
> + GET_REV(p_entry));
> + ep.ep_name = type2epname(p_entry->type);
> + ep.bar = GET_BAR(p_entry);
> + ep.bar_off = GET_BAR_OFF(p_entry);
here is the bar_off type overlow
> + ep.size = type2size(p_entry->type);
> + ep.regmap = type2regmap(p_entry->type);
> + ep.regmap_ver = regmap_ver;
> + ret = xrt_md_add_endpoint(DEV(vsec->pdev), vsec->metadata, &ep);
> + if (ret) {
> + xrt_err(vsec->pdev, "add ep failed, ret %d", ret);
> + goto failed;
> + }
> +
> +failed:
> + return ret;
> +}
> +
> +static int xrt_vsec_create_metadata(struct xrt_vsec *vsec)
> +{
> + struct xrt_vsec_entry entry;
> + int i, ret;
> +
> + ret = xrt_md_create(&vsec->pdev->dev, &vsec->metadata);
> + if (ret) {
> + xrt_err(vsec->pdev, "create metadata failed");
> + return ret;
> + }
> +
> + for (i = 0; i * sizeof(entry) < vsec->length -
> + sizeof(struct xrt_vsec_header); i++) {
> + read_entry(vsec, i, &entry);
> + xrt_vsec_add_node(vsec, vsec->metadata, &entry);
This can fail.
> + }
> +
> + return 0;
> +}
> +
> +static int xrt_vsec_ioctl(struct platform_device *pdev, u32 cmd, void *arg)
> +{
> + int ret = 0;
> +
> + switch (cmd) {
> + case XRT_XLEAF_EVENT:
> + /* Does not handle any event. */
> + break;
> + default:
> + ret = -EINVAL;
> + xrt_err(pdev, "should never been called");
> + break;
> + }
This function looks like a noop.  Is anything going to be added to this later ?
> +
> + return ret;
> +}
> +
> +static int xrt_vsec_mapio(struct xrt_vsec *vsec)
> +{
> + struct xrt_subdev_platdata *pdata = DEV_PDATA(vsec->pdev);
> + const u32 *bar;
> + const u64 *bar_off;
> + struct resource *res = NULL;
> + ulong addr;
> + int ret;
> +
> + if (!pdata || xrt_md_size(DEV(vsec->pdev), pdata->xsp_dtb) == XRT_MD_INVALID_LENGTH) {
> + xrt_err(vsec->pdev, "empty metadata");
> + return -EINVAL;
> + }
> +
> + ret = xrt_md_get_prop(DEV(vsec->pdev), pdata->xsp_dtb, XRT_MD_NODE_VSEC,
> + NULL, XRT_MD_PROP_BAR_IDX, (const void **)&bar, NULL);
> + if (ret) {
> + xrt_err(vsec->pdev, "failed to get bar idx, ret %d", ret);
> + return -EINVAL;
> + }
> +
> + ret = xrt_md_get_prop(DEV(vsec->pdev), pdata->xsp_dtb, XRT_MD_NODE_VSEC,
> + NULL, XRT_MD_PROP_OFFSET, (const void **)&bar_off, NULL);
> + if (ret) {
> + xrt_err(vsec->pdev, "failed to get bar off, ret %d", ret);
> + return -EINVAL;
> + }
> +
> + xrt_info(vsec->pdev, "Map vsec at bar %d, offset 0x%llx",
> + be32_to_cpu(*bar), be64_to_cpu(*bar_off));
> +
> + xleaf_get_barres(vsec->pdev, &res, be32_to_cpu(*bar));
> + if (!res) {
> + xrt_err(vsec->pdev, "failed to get bar addr");
> + return -EINVAL;
> + }
> +
> + addr = res->start + (ulong)be64_to_cpu(*bar_off);
review this type, addr is ulong and bar_off is not.
> +
> + vsec->base = ioremap(addr, sizeof(struct xrt_vsec_header));
> + if (!vsec->base) {
> + xrt_err(vsec->pdev, "Map header failed");
> + return -EIO;
> + }

why the double call on ioremap ?

just do the last one.

> +
> + vsec->length = head_rd(vsec, length);
> + iounmap(vsec->base);
> + vsec->base = ioremap(addr, vsec->length);
> + if (!vsec->base) {
> + xrt_err(vsec->pdev, "map failed");
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +static int xrt_vsec_remove(struct platform_device *pdev)
> +{
> + struct xrt_vsec *vsec;
> +
> + vsec = platform_get_drvdata(pdev);
> +
> + if (vsec->base) {
> + iounmap(vsec->base);
> + vsec->base = NULL;
> + }
> +
> + vfree(vsec->metadata);
> +
> + return 0;
> +}
> +
> +static int xrt_vsec_probe(struct platform_device *pdev)
> +{
> + struct xrt_vsec *vsec;
> + int ret = 0;
> +
> + vsec = devm_kzalloc(&pdev->dev, sizeof(*vsec), GFP_KERNEL);
> + if (!vsec)
> + return -ENOMEM;
> +
> + vsec->pdev = pdev;
> + platform_set_drvdata(pdev, vsec);
> +
> + ret = xrt_vsec_mapio(vsec);
> + if (ret)
> + goto failed;
> +
> + ret = xrt_vsec_create_metadata(vsec);
> + if (ret) {
> + xrt_err(pdev, "create metadata failed, ret %d", ret);
> + goto failed;
> + }
> + ret = xleaf_create_group(pdev, vsec->metadata);
> + if (ret < 0)
> + xrt_err(pdev, "create group failed, ret %d", ret);
> + else
> + ret = 0;

why is it just

if (ret)

fail ?

Tom

> +
> +failed:
> + if (ret)
> + xrt_vsec_remove(pdev);
> +
> + return ret;
> +}
> +
> +static struct xrt_subdev_endpoints xrt_vsec_endpoints[] = {
> + {
> + .xse_names = (struct xrt_subdev_ep_names []){
> + { .ep_name = XRT_MD_NODE_VSEC },
> + { NULL },
> + },
> + .xse_min_ep = 1,
> + },
> + { 0 },
> +};
> +
> +static struct xrt_subdev_drvdata xrt_vsec_data = {
> + .xsd_dev_ops = {
> + .xsd_ioctl = xrt_vsec_ioctl,
> + },
> +};
> +
> +static const struct platform_device_id xrt_vsec_table[] = {
> + { XRT_VSEC, (kernel_ulong_t)&xrt_vsec_data },
> + { },
> +};
> +
> +static struct platform_driver xrt_vsec_driver = {
> + .driver = {
> + .name = XRT_VSEC,
> + },
> + .probe = xrt_vsec_probe,
> + .remove = xrt_vsec_remove,
> + .id_table = xrt_vsec_table,
> +};
> +
> +void vsec_leaf_init_fini(bool init)
> +{
> + if (init)
> + xleaf_register_driver(XRT_SUBDEV_VSEC, &xrt_vsec_driver, xrt_vsec_endpoints);
> + else
> + xleaf_unregister_driver(XRT_SUBDEV_VSEC);
> +}