Re: [PATCH V5 XRT Alveo 19/20] fpga: xrt: partition isolation driver

Tom Rix
2021-05-04T14:13:20Z

On 4/27/21 1:54 PM, Lizhi Hou wrote:
> Add partition isolation xrt driver. partition isolation is
> a hardware function discovered by walking firmware metadata.
> A xrt device node will be created for it. Partition isolation
> function isolate the different fpga regions
>
> Signed-off-by: Sonal Santan <sonal.santan@xilinx.com>
> Signed-off-by: Max Zhen <max.zhen@xilinx.com>
> Signed-off-by: Lizhi Hou <lizhi.hou@xilinx.com>

v4 was fine. Please add my Reviewed-by line

Reviewed-by: Tom Rix <trix@redhat.com>

> ---
> drivers/fpga/xrt/include/xleaf/axigate.h | 23 ++
> drivers/fpga/xrt/lib/xleaf/axigate.c | 325 +++++++++++++++++++++++
> 2 files changed, 348 insertions(+)
> create mode 100644 drivers/fpga/xrt/include/xleaf/axigate.h
> create mode 100644 drivers/fpga/xrt/lib/xleaf/axigate.c
>
> diff --git a/drivers/fpga/xrt/include/xleaf/axigate.h b/drivers/fpga/xrt/include/xleaf/axigate.h
> new file mode 100644
> index 000000000000..58f32c76dca1
> --- /dev/null
> +++ b/drivers/fpga/xrt/include/xleaf/axigate.h
> @@ -0,0 +1,23 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + * Lizhi Hou <Lizhi.Hou@xilinx.com>
> + */
> +
> +#ifndef _XRT_AXIGATE_H_
> +#define _XRT_AXIGATE_H_
> +
> +#include "xleaf.h"
> +#include "metadata.h"
> +
> +/*
> + * AXIGATE driver leaf calls.
> + */
> +enum xrt_axigate_leaf_cmd {
> + XRT_AXIGATE_CLOSE = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
> + XRT_AXIGATE_OPEN,
> +};
> +
> +#endif /* _XRT_AXIGATE_H_ */
> diff --git a/drivers/fpga/xrt/lib/xleaf/axigate.c b/drivers/fpga/xrt/lib/xleaf/axigate.c
> new file mode 100644
> index 000000000000..493707b782e4
> --- /dev/null
> +++ b/drivers/fpga/xrt/lib/xleaf/axigate.c
> @@ -0,0 +1,325 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Xilinx Alveo FPGA AXI Gate Driver
> + *
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + * Lizhi Hou<Lizhi.Hou@xilinx.com>
> + */
> +
> +#include <linux/mod_devicetable.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/regmap.h>
> +#include <linux/io.h>
> +#include "metadata.h"
> +#include "xleaf.h"
> +#include "xleaf/axigate.h"
> +
> +#define XRT_AXIGATE "xrt_axigate"
> +
> +#define XRT_AXIGATE_WRITE_REG 0
> +#define XRT_AXIGATE_READ_REG 8
> +
> +#define XRT_AXIGATE_CTRL_CLOSE 0
> +#define XRT_AXIGATE_CTRL_OPEN_BIT0 1
> +#define XRT_AXIGATE_CTRL_OPEN_BIT1 2
> +
> +#define XRT_AXIGATE_INTERVAL 500 /* ns */
> +
> +struct xrt_axigate {
> + struct xrt_device *xdev;
> + struct regmap *regmap;
> + struct mutex gate_lock; /* gate dev lock */
> + void *evt_hdl;
> + const char *ep_name;
> + bool gate_closed;
> +};
> +
> +XRT_DEFINE_REGMAP_CONFIG(axigate_regmap_config);
> +
> +/* the ep names are in the order of hardware layers */
> +static const char * const xrt_axigate_epnames[] = {
> + XRT_MD_NODE_GATE_PLP, /* PLP: Provider Logic Partition */
> + XRT_MD_NODE_GATE_ULP /* ULP: User Logic Partition */
> +};
> +
> +static inline int close_gate(struct xrt_axigate *gate)
> +{
> + u32 val;
> + int ret;
> +
> + ret = regmap_write(gate->regmap, XRT_AXIGATE_WRITE_REG, XRT_AXIGATE_CTRL_CLOSE);
> + if (ret) {
> + xrt_err(gate->xdev, "write gate failed %d", ret);
> + return ret;
> + }
> + ndelay(XRT_AXIGATE_INTERVAL);
> + /*
> + * Legacy hardware requires extra read work properly.
> + * This is not on critical path, thus the extra read should not impact performance much.
> + */
> + ret = regmap_read(gate->regmap, XRT_AXIGATE_READ_REG, &val);
> + if (ret) {
> + xrt_err(gate->xdev, "read gate failed %d", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static inline int open_gate(struct xrt_axigate *gate)
> +{
> + u32 val;
> + int ret;
> +
> + ret = regmap_write(gate->regmap, XRT_AXIGATE_WRITE_REG, XRT_AXIGATE_CTRL_OPEN_BIT1);
> + if (ret) {
> + xrt_err(gate->xdev, "write 2 failed %d", ret);
> + return ret;
> + }
> + ndelay(XRT_AXIGATE_INTERVAL);
> + /*
> + * Legacy hardware requires extra read work properly.
> + * This is not on critical path, thus the extra read should not impact performance much.
> + */
> + ret = regmap_read(gate->regmap, XRT_AXIGATE_READ_REG, &val);
> + if (ret) {
> + xrt_err(gate->xdev, "read 2 failed %d", ret);
> + return ret;
> + }
> + ret = regmap_write(gate->regmap, XRT_AXIGATE_WRITE_REG,
> + XRT_AXIGATE_CTRL_OPEN_BIT0 | XRT_AXIGATE_CTRL_OPEN_BIT1);
> + if (ret) {
> + xrt_err(gate->xdev, "write 3 failed %d", ret);
> + return ret;
> + }
> + ndelay(XRT_AXIGATE_INTERVAL);
> + ret = regmap_read(gate->regmap, XRT_AXIGATE_READ_REG, &val);
> + if (ret) {
> + xrt_err(gate->xdev, "read 3 failed %d", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int xrt_axigate_epname_idx(struct xrt_device *xdev)
> +{
> + struct resource *res;
> + int ret, i;
> +
> + res = xrt_get_resource(xdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + xrt_err(xdev, "Empty Resource!");
> + return -EINVAL;
> + }
> +
> + for (i = 0; i < ARRAY_SIZE(xrt_axigate_epnames); i++) {
> + ret = strncmp(xrt_axigate_epnames[i], res->name,
> + strlen(xrt_axigate_epnames[i]) + 1);
> + if (!ret)
> + return i;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int xrt_axigate_close(struct xrt_device *xdev)
> +{
> + struct xrt_axigate *gate;
> + u32 status = 0;
> + int ret;
> +
> + gate = xrt_get_drvdata(xdev);
> +
> + mutex_lock(&gate->gate_lock);
> + ret = regmap_read(gate->regmap, XRT_AXIGATE_READ_REG, &status);
> + if (ret) {
> + xrt_err(xdev, "read gate failed %d", ret);
> + goto failed;
> + }
> + if (status) { /* gate is opened */
> + xleaf_broadcast_event(xdev, XRT_EVENT_PRE_GATE_CLOSE, false);
> + ret = close_gate(gate);
> + if (ret)
> + goto failed;
> + }
> +
> + gate->gate_closed = true;
> +
> +failed:
> + mutex_unlock(&gate->gate_lock);
> +
> + xrt_info(xdev, "close gate %s", gate->ep_name);
> + return ret;
> +}
> +
> +static int xrt_axigate_open(struct xrt_device *xdev)
> +{
> + struct xrt_axigate *gate;
> + u32 status;
> + int ret;
> +
> + gate = xrt_get_drvdata(xdev);
> +
> + mutex_lock(&gate->gate_lock);
> + ret = regmap_read(gate->regmap, XRT_AXIGATE_READ_REG, &status);
> + if (ret) {
> + xrt_err(xdev, "read gate failed %d", ret);
> + goto failed;
> + }
> + if (!status) { /* gate is closed */
> + ret = open_gate(gate);
> + if (ret)
> + goto failed;
> + xleaf_broadcast_event(xdev, XRT_EVENT_POST_GATE_OPEN, true);
> + /* xrt_axigate_open() could be called in event cb, thus
> + * we can not wait for the completes
> + */
> + }
> +
> + gate->gate_closed = false;
> +
> +failed:
> + mutex_unlock(&gate->gate_lock);
> +
> + xrt_info(xdev, "open gate %s", gate->ep_name);
> + return ret;
> +}
> +
> +static void xrt_axigate_event_cb(struct xrt_device *xdev, void *arg)
> +{
> + struct xrt_axigate *gate = xrt_get_drvdata(xdev);
> + struct xrt_event *evt = (struct xrt_event *)arg;
> + enum xrt_events e = evt->xe_evt;
> + struct xrt_device *leaf;
> + enum xrt_subdev_id id;
> + struct resource *res;
> + int instance;
> +
> + if (e != XRT_EVENT_POST_CREATION)
> + return;
> +
> + instance = evt->xe_subdev.xevt_subdev_instance;
> + id = evt->xe_subdev.xevt_subdev_id;
> + if (id != XRT_SUBDEV_AXIGATE)
> + return;
> +
> + leaf = xleaf_get_leaf_by_id(xdev, id, instance);
> + if (!leaf)
> + return;
> +
> + res = xrt_get_resource(leaf, IORESOURCE_MEM, 0);
> + if (!res || !strncmp(res->name, gate->ep_name, strlen(res->name) + 1)) {
> + xleaf_put_leaf(xdev, leaf);
> + return;
> + }
> +
> + /* higher level axigate instance created, make sure the gate is opened. */
> + if (xrt_axigate_epname_idx(leaf) > xrt_axigate_epname_idx(xdev))
> + xrt_axigate_open(xdev);
> + else
> + xleaf_call(leaf, XRT_AXIGATE_OPEN, NULL);
> +
> + xleaf_put_leaf(xdev, leaf);
> +}
> +
> +static int
> +xrt_axigate_leaf_call(struct xrt_device *xdev, u32 cmd, void *arg)
> +{
> + int ret = 0;
> +
> + switch (cmd) {
> + case XRT_XLEAF_EVENT:
> + xrt_axigate_event_cb(xdev, arg);
> + break;
> + case XRT_AXIGATE_CLOSE:
> + ret = xrt_axigate_close(xdev);
> + break;
> + case XRT_AXIGATE_OPEN:
> + ret = xrt_axigate_open(xdev);
> + break;
> + default:
> + xrt_err(xdev, "unsupported cmd %d", cmd);
> + return -EINVAL;
> + }
> +
> + return ret;
> +}
> +
> +static int xrt_axigate_probe(struct xrt_device *xdev)
> +{
> + struct xrt_axigate *gate = NULL;
> + void __iomem *base = NULL;
> + struct resource *res;
> + int ret;
> +
> + gate = devm_kzalloc(&xdev->dev, sizeof(*gate), GFP_KERNEL);
> + if (!gate)
> + return -ENOMEM;
> +
> + gate->xdev = xdev;
> + xrt_set_drvdata(xdev, gate);
> +
> + xrt_info(xdev, "probing...");
> + res = xrt_get_resource(xdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + xrt_err(xdev, "Empty resource 0");
> + ret = -EINVAL;
> + goto failed;
> + }
> +
> + base = devm_ioremap_resource(&xdev->dev, res);
> + if (IS_ERR(base)) {
> + xrt_err(xdev, "map base iomem failed");
> + ret = PTR_ERR(base);
> + goto failed;
> + }
> +
> + gate->regmap = devm_regmap_init_mmio(&xdev->dev, base, &axigate_regmap_config);
> + if (IS_ERR(gate->regmap)) {
> + xrt_err(xdev, "regmap %pR failed", res);
> + ret = PTR_ERR(gate->regmap);
> + goto failed;
> + }
> + gate->ep_name = res->name;
> +
> + mutex_init(&gate->gate_lock);
> +
> + return 0;
> +
> +failed:
> + return ret;
> +}
> +
> +static struct xrt_dev_endpoints xrt_axigate_endpoints[] = {
> + {
> + .xse_names = (struct xrt_dev_ep_names[]) {
> + { .ep_name = XRT_MD_NODE_GATE_ULP },
> + { NULL },
> + },
> + .xse_min_ep = 1,
> + },
> + {
> + .xse_names = (struct xrt_dev_ep_names[]) {
> + { .ep_name = XRT_MD_NODE_GATE_PLP },
> + { NULL },
> + },
> + .xse_min_ep = 1,
> + },
> + { 0 },
> +};
> +
> +static struct xrt_driver xrt_axigate_driver = {
> + .driver = {
> + .name = XRT_AXIGATE,
> + },
> + .subdev_id = XRT_SUBDEV_AXIGATE,
> + .endpoints = xrt_axigate_endpoints,
> + .probe = xrt_axigate_probe,
> + .leaf_call = xrt_axigate_leaf_call,
> +};
> +
> +XRT_LEAF_INIT_FINI_FUNC(axigate);