[PATCH V3 XRT Alveo 17/18] fpga: xrt: partition isolation platform driver

[Lizhi Hou]

Add partition isolation platform driver. partition isolation is
a hardware function discovered by walking firmware metadata.
A platform device node will be created for it. Partition isolation
function isolate the different fpga regions

Signed-off-by: Sonal Santan <sonal.santan@xxxxxxxxxx>
Signed-off-by: Max Zhen <max.zhen@xxxxxxxxxx>
Signed-off-by: Lizhi Hou <lizhih@xxxxxxxxxx>
---
 drivers/fpga/xrt/include/xleaf/axigate.h |  25 ++
 drivers/fpga/xrt/lib/xleaf/axigate.c     | 298 +++++++++++++++++++++++
 2 files changed, 323 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..2cef71e13b30
--- /dev/null
+++ b/drivers/fpga/xrt/include/xleaf/axigate.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Header file for XRT Axigate Leaf Driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *	Lizhi Hou <Lizhi.Hou@xxxxxxxxxx>
+ */
+
+#ifndef _XRT_AXIGATE_H_
+#define _XRT_AXIGATE_H_
+
+#include "xleaf.h"
+#include "metadata.h"
+
+/*
+ * AXIGATE driver IOCTL calls.
+ */
+enum xrt_axigate_ioctl_cmd {
+	XRT_AXIGATE_FREEZE = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
+	XRT_AXIGATE_FREE,
+};
+
+#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..382969f9925f
--- /dev/null
+++ b/drivers/fpga/xrt/lib/xleaf/axigate.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Alveo FPGA AXI Gate Driver
+ *
+ * Copyright (C) 2020-2021 Xilinx, Inc.
+ *
+ * Authors:
+ *      Lizhi Hou<Lizhi.Hou@xxxxxxxxxx>
+ */
+
+#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/axigate.h"
+
+#define XRT_AXIGATE "xrt_axigate"
+
+struct axigate_regs {
+	u32		iag_wr;
+	u32		iag_rvsd;
+	u32		iag_rd;
+} __packed;
+
+struct xrt_axigate {
+	struct platform_device	*pdev;
+	void			*base;
+	struct mutex		gate_lock; /* gate dev lock */
+
+	void			*evt_hdl;
+	const char		*ep_name;
+
+	bool			gate_freezed;
+};
+
+/* the ep names are in the order of hardware layers */
+static const char * const xrt_axigate_epnames[] = {
+	XRT_MD_NODE_GATE_PLP,
+	XRT_MD_NODE_GATE_ULP,
+	NULL
+};
+
+#define reg_rd(g, r)						\
+	ioread32((void *)(g)->base + offsetof(struct axigate_regs, r))
+#define reg_wr(g, v, r)						\
+	iowrite32(v, (void *)(g)->base + offsetof(struct axigate_regs, r))
+
+static inline void freeze_gate(struct xrt_axigate *gate)
+{
+	reg_wr(gate, 0, iag_wr);
+	ndelay(500);
+	reg_rd(gate, iag_rd);
+}
+
+static inline void free_gate(struct xrt_axigate *gate)
+{
+	reg_wr(gate, 0x2, iag_wr);
+	ndelay(500);
+	(void)reg_rd(gate, iag_rd);
+	reg_wr(gate, 0x3, iag_wr);
+	ndelay(500);
+	reg_rd(gate, iag_rd);
+}
+
+static int xrt_axigate_epname_idx(struct platform_device *pdev)
+{
+	int			i;
+	int			ret;
+	struct resource		*res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		xrt_err(pdev, "Empty Resource!");
+		return -EINVAL;
+	}
+
+	for (i = 0; xrt_axigate_epnames[i]; i++) {
+		ret = strncmp(xrt_axigate_epnames[i], res->name,
+			      strlen(xrt_axigate_epnames[i]) + 1);
+		if (!ret)
+			break;
+	}
+
+	ret = (xrt_axigate_epnames[i]) ? i : -EINVAL;
+	return ret;
+}
+
+static void xrt_axigate_freeze(struct platform_device *pdev)
+{
+	struct xrt_axigate	*gate;
+	u32			freeze = 0;
+
+	gate = platform_get_drvdata(pdev);
+
+	mutex_lock(&gate->gate_lock);
+	freeze = reg_rd(gate, iag_rd);
+	if (freeze) {		/* gate is opened */
+		xleaf_broadcast_event(pdev, XRT_EVENT_PRE_GATE_CLOSE, false);
+		freeze_gate(gate);
+	}
+
+	gate->gate_freezed = true;
+	mutex_unlock(&gate->gate_lock);
+
+	xrt_info(pdev, "freeze gate %s", gate->ep_name);
+}
+
+static void xrt_axigate_free(struct platform_device *pdev)
+{
+	struct xrt_axigate	*gate;
+	u32			freeze;
+
+	gate = platform_get_drvdata(pdev);
+
+	mutex_lock(&gate->gate_lock);
+	freeze = reg_rd(gate, iag_rd);
+	if (!freeze) {		/* gate is closed */
+		free_gate(gate);
+		xleaf_broadcast_event(pdev, XRT_EVENT_POST_GATE_OPEN, true);
+		/* xrt_axigate_free() could be called in event cb, thus
+		 * we can not wait for the completes
+		 */
+	}
+
+	gate->gate_freezed = false;
+	mutex_unlock(&gate->gate_lock);
+
+	xrt_info(pdev, "free gate %s", gate->ep_name);
+}
+
+static void xrt_axigate_event_cb(struct platform_device *pdev, void *arg)
+{
+	struct platform_device *leaf;
+	struct xrt_event *evt = (struct xrt_event *)arg;
+	enum xrt_events e = evt->xe_evt;
+	enum xrt_subdev_id id = evt->xe_subdev.xevt_subdev_id;
+	int instance = evt->xe_subdev.xevt_subdev_instance;
+	struct xrt_axigate *gate = platform_get_drvdata(pdev);
+	struct resource	*res;
+
+	switch (e) {
+	case XRT_EVENT_POST_CREATION:
+		break;
+	default:
+		return;
+	}
+
+	if (id != XRT_SUBDEV_AXIGATE)
+		return;
+
+	leaf = xleaf_get_leaf_by_id(pdev, id, instance);
+	if (!leaf)
+		return;
+
+	res = platform_get_resource(leaf, IORESOURCE_MEM, 0);
+	if (!res || !strncmp(res->name, gate->ep_name, strlen(res->name) + 1)) {
+		(void)xleaf_put_leaf(pdev, leaf);
+		return;
+	}
+
+	/*
+	 * higher level axigate instance created,
+	 * make sure the gate is openned. This covers 1RP flow which
+	 * has plp gate as well.
+	 */
+	if (xrt_axigate_epname_idx(leaf) > xrt_axigate_epname_idx(pdev))
+		xrt_axigate_free(pdev);
+	else
+		xleaf_ioctl(leaf, XRT_AXIGATE_FREE, NULL);
+
+	(void)xleaf_put_leaf(pdev, leaf);
+}
+
+static int
+xrt_axigate_leaf_ioctl(struct platform_device *pdev, u32 cmd, void *arg)
+{
+	switch (cmd) {
+	case XRT_XLEAF_EVENT:
+		xrt_axigate_event_cb(pdev, arg);
+		break;
+	case XRT_AXIGATE_FREEZE:
+		xrt_axigate_freeze(pdev);
+		break;
+	case XRT_AXIGATE_FREE:
+		xrt_axigate_free(pdev);
+		break;
+	default:
+		xrt_err(pdev, "unsupported cmd %d", cmd);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int xrt_axigate_remove(struct platform_device *pdev)
+{
+	struct xrt_axigate	*gate;
+
+	gate = platform_get_drvdata(pdev);
+
+	if (gate->base)
+		iounmap(gate->base);
+
+	platform_set_drvdata(pdev, NULL);
+	devm_kfree(&pdev->dev, gate);
+
+	return 0;
+}
+
+static int xrt_axigate_probe(struct platform_device *pdev)
+{
+	struct xrt_axigate	*gate;
+	struct resource		*res;
+	int			ret;
+
+	gate = devm_kzalloc(&pdev->dev, sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return -ENOMEM;
+
+	gate->pdev = pdev;
+	platform_set_drvdata(pdev, gate);
+
+	xrt_info(pdev, "probing...");
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		xrt_err(pdev, "Empty resource 0");
+		ret = -EINVAL;
+		goto failed;
+	}
+
+	gate->base = ioremap(res->start, res->end - res->start + 1);
+	if (!gate->base) {
+		xrt_err(pdev, "map base iomem failed");
+		ret = -EFAULT;
+		goto failed;
+	}
+
+	gate->ep_name = res->name;
+
+	mutex_init(&gate->gate_lock);
+
+	return 0;
+
+failed:
+	xrt_axigate_remove(pdev);
+	return ret;
+}
+
+static struct xrt_subdev_endpoints xrt_axigate_endpoints[] = {
+	{
+		.xse_names = (struct xrt_subdev_ep_names[]) {
+			{ .ep_name = "ep_pr_isolate_ulp_00" },
+			{ NULL },
+		},
+		.xse_min_ep = 1,
+	},
+	{
+		.xse_names = (struct xrt_subdev_ep_names[]) {
+			{ .ep_name = "ep_pr_isolate_plp_00" },
+			{ NULL },
+		},
+		.xse_min_ep = 1,
+	},
+	{ 0 },
+};
+
+static struct xrt_subdev_drvdata xrt_axigate_data = {
+	.xsd_dev_ops = {
+		.xsd_ioctl = xrt_axigate_leaf_ioctl,
+	},
+};
+
+static const struct platform_device_id xrt_axigate_table[] = {
+	{ XRT_AXIGATE, (kernel_ulong_t)&xrt_axigate_data },
+	{ },
+};
+
+static struct platform_driver xrt_axigate_driver = {
+	.driver = {
+		.name = XRT_AXIGATE,
+	},
+	.probe = xrt_axigate_probe,
+	.remove = xrt_axigate_remove,
+	.id_table = xrt_axigate_table,
+};
+
+void axigate_leaf_init_fini(bool init)
+{
+	if (init) {
+		xleaf_register_driver(XRT_SUBDEV_AXIGATE,
+				      &xrt_axigate_driver, xrt_axigate_endpoints);
+	} else {
+		xleaf_unregister_driver(XRT_SUBDEV_AXIGATE);
+	}
+}
-- 
2.18.4