fpga: add intel stratix10 soc fpga manager driver

Add driver for reconfiguring Intel Stratix10 SoC FPGA devices.
This driver communicates through the Intel service layer driver
which does communication with privileged hardware (that does the
FPGA programming) through a secure mailbox.

Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Richard Gong <richard.gong@intel.com>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 542 insertions, 0 deletions

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 1ebcef4bab5b..0bb7b5cd6cdc 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -56,6 +56,12 @@ config FPGA_MGR_ZYNQ_FPGA
 	help
 	  FPGA manager driver support for Xilinx Zynq FPGAs.
 
+config FPGA_MGR_STRATIX10_SOC
+	tristate "Intel Stratix10 SoC FPGA Manager"
+	depends on (ARCH_STRATIX10 && INTEL_STRATIX10_SERVICE)
+	help
+	  FPGA manager driver support for the Intel Stratix10 SoC.
+
 config FPGA_MGR_XILINX_SPI
 	tristate "Xilinx Configuration over Slave Serial (SPI)"
 	depends on SPI
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index 7a2d73ba7122..c0dd4c82fbdb 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_FPGA_MGR_ICE40_SPI)	+= ice40-spi.o
 obj-$(CONFIG_FPGA_MGR_MACHXO2_SPI)	+= machxo2-spi.o
 obj-$(CONFIG_FPGA_MGR_SOCFPGA)		+= socfpga.o
 obj-$(CONFIG_FPGA_MGR_SOCFPGA_A10)	+= socfpga-a10.o
+obj-$(CONFIG_FPGA_MGR_STRATIX10_SOC)	+= stratix10-soc.o
 obj-$(CONFIG_FPGA_MGR_TS73XX)		+= ts73xx-fpga.o
 obj-$(CONFIG_FPGA_MGR_XILINX_SPI)	+= xilinx-spi.o
 obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA)	+= zynq-fpga.o
diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
new file mode 100644
index 000000000000..a1a09e04fab8
--- /dev/null
+++ b/drivers/fpga/stratix10-soc.c
@@ -0,0 +1,535 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * FPGA Manager Driver for Intel Stratix10 SoC
+ *
+ *  Copyright (C) 2018 Intel Corporation
+ */
+#include <linux/completion.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/firmware/intel/stratix10-svc-client.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+
+/*
+ * FPGA programming requires a higher level of privilege (EL3), per the SoC
+ * design.
+ */
+#define NUM_SVC_BUFS	4
+#define SVC_BUF_SIZE	SZ_512K
+
+/* Indicates buffer is in use if set */
+#define SVC_BUF_LOCK	0
+
+#define S10_BUFFER_TIMEOUT (msecs_to_jiffies(SVC_RECONFIG_BUFFER_TIMEOUT_MS))
+#define S10_RECONFIG_TIMEOUT (msecs_to_jiffies(SVC_RECONFIG_REQUEST_TIMEOUT_MS))
+
+/*
+ * struct s10_svc_buf
+ * buf:  virtual address of buf provided by service layer
+ * lock: locked if buffer is in use
+ */
+struct s10_svc_buf {
+	char *buf;
+	unsigned long lock;
+};
+
+struct s10_priv {
+	struct stratix10_svc_chan *chan;
+	struct stratix10_svc_client client;
+	struct completion status_return_completion;
+	struct s10_svc_buf svc_bufs[NUM_SVC_BUFS];
+	unsigned long status;
+};
+
+static int s10_svc_send_msg(struct s10_priv *priv,
+			    enum stratix10_svc_command_code command,
+			    void *payload, u32 payload_length)
+{
+	struct stratix10_svc_chan *chan = priv->chan;
+	struct device *dev = priv->client.dev;
+	struct stratix10_svc_client_msg msg;
+	int ret;
+
+	dev_dbg(dev, "%s cmd=%d payload=%p length=%d\n",
+		__func__, command, payload, payload_length);
+
+	msg.command = command;
+	msg.payload = payload;
+	msg.payload_length = payload_length;
+
+	ret = stratix10_svc_send(chan, &msg);
+	dev_dbg(dev, "stratix10_svc_send returned status %d\n", ret);
+
+	return ret;
+}
+
+/*
+ * Free buffers allocated from the service layer's pool that are not in use.
+ * Return true when all buffers are freed.
+ */
+static bool s10_free_buffers(struct fpga_manager *mgr)
+{
+	struct s10_priv *priv = mgr->priv;
+	uint num_free = 0;
+	uint i;
+
+	for (i = 0; i < NUM_SVC_BUFS; i++) {
+		if (!priv->svc_bufs[i].buf) {
+			num_free++;
+			continue;
+		}
+
+		if (!test_and_set_bit_lock(SVC_BUF_LOCK,
+					   &priv->svc_bufs[i].lock)) {
+			stratix10_svc_free_memory(priv->chan,
+						  priv->svc_bufs[i].buf);
+			priv->svc_bufs[i].buf = NULL;
+			num_free++;
+		}
+	}
+
+	return num_free == NUM_SVC_BUFS;
+}
+
+/*
+ * Returns count of how many buffers are not in use.
+ */
+static uint s10_free_buffer_count(struct fpga_manager *mgr)
+{
+	struct s10_priv *priv = mgr->priv;
+	uint num_free = 0;
+	uint i;
+
+	for (i = 0; i < NUM_SVC_BUFS; i++)
+		if (!priv->svc_bufs[i].buf)
+			num_free++;
+
+	return num_free;
+}
+
+/*
+ * s10_unlock_bufs
+ * Given the returned buffer address, match that address to our buffer struct
+ * and unlock that buffer.  This marks it as available to be refilled and sent
+ * (or freed).
+ * priv: private data
+ * kaddr: kernel address of buffer that was returned from service layer
+ */
+static void s10_unlock_bufs(struct s10_priv *priv, void *kaddr)
+{
+	uint i;
+
+	if (!kaddr)
+		return;
+
+	for (i = 0; i < NUM_SVC_BUFS; i++)
+		if (priv->svc_bufs[i].buf == kaddr) {
+			clear_bit_unlock(SVC_BUF_LOCK,
+					 &priv->svc_bufs[i].lock);
+			return;
+		}
+
+	WARN(1, "Unknown buffer returned from service layer %p\n", kaddr);
+}
+
+/*
+ * s10_receive_callback - callback for service layer to use to provide client
+ * (this driver) messages received through the mailbox.
+ * client: service layer client struct
+ * data: message from service layer
+ */
+static void s10_receive_callback(struct stratix10_svc_client *client,
+				 struct stratix10_svc_cb_data *data)
+{
+	struct s10_priv *priv = client->priv;
+	u32 status;
+	int i;
+
+	WARN_ONCE(!data, "%s: stratix10_svc_rc_data = NULL", __func__);
+
+	status = data->status;
+
+	/*
+	 * Here we set status bits as we receive them.  Elsewhere, we always use
+	 * test_and_clear_bit() to check status in priv->status
+	 */
+	for (i = 0; i <= SVC_STATUS_RECONFIG_ERROR; i++)
+		if (status & (1 << i))
+			set_bit(i, &priv->status);
+
+	if (status & BIT(SVC_STATUS_RECONFIG_BUFFER_DONE)) {
+		s10_unlock_bufs(priv, data->kaddr1);
+		s10_unlock_bufs(priv, data->kaddr2);
+		s10_unlock_bufs(priv, data->kaddr3);
+	}
+
+	complete(&priv->status_return_completion);
+}
+
+/*
+ * s10_ops_write_init - prepare for FPGA reconfiguration by requesting
+ * partial reconfig and allocating buffers from the service layer.
+ */
+static int s10_ops_write_init(struct fpga_manager *mgr,
+			      struct fpga_image_info *info,
+			      const char *buf, size_t count)
+{
+	struct s10_priv *priv = mgr->priv;
+	struct device *dev = priv->client.dev;
+	struct stratix10_svc_command_config_type ctype;
+	char *kbuf;
+	uint i;
+	int ret;
+
+	ctype.flags = 0;
+	if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
+		dev_dbg(dev, "Requesting partial reconfiguration.\n");
+		ctype.flags |= BIT(COMMAND_RECONFIG_FLAG_PARTIAL);
+	} else {
+		dev_dbg(dev, "Requesting full reconfiguration.\n");
+	}
+
+	reinit_completion(&priv->status_return_completion);
+	ret = s10_svc_send_msg(priv, COMMAND_RECONFIG,
+			       &ctype, sizeof(ctype));
+	if (ret < 0)
+		goto init_done;
+
+	ret = wait_for_completion_interruptible_timeout(
+		&priv->status_return_completion, S10_RECONFIG_TIMEOUT);
+	if (!ret) {
+		dev_err(dev, "timeout waiting for RECONFIG_REQUEST\n");
+		ret = -ETIMEDOUT;
+		goto init_done;
+	}
+	if (ret < 0) {
+		dev_err(dev, "error (%d) waiting for RECONFIG_REQUEST\n", ret);
+		goto init_done;
+	}
+
+	ret = 0;
+	if (!test_and_clear_bit(SVC_STATUS_RECONFIG_REQUEST_OK,
+				&priv->status)) {
+		ret = -ETIMEDOUT;
+		goto init_done;
+	}
+
+	/* Allocate buffers from the service layer's pool. */
+	for (i = 0; i < NUM_SVC_BUFS; i++) {
+		kbuf = stratix10_svc_allocate_memory(priv->chan, SVC_BUF_SIZE);
+		if (!kbuf) {
+			s10_free_buffers(mgr);
+			ret = -ENOMEM;
+			goto init_done;
+		}
+
+		priv->svc_bufs[i].buf = kbuf;
+		priv->svc_bufs[i].lock = 0;
+	}
+
+init_done:
+	stratix10_svc_done(priv->chan);
+	return ret;
+}
+
+/*
+ * s10_send_buf - send a buffer to the service layer queue
+ * mgr: fpga manager struct
+ * buf: fpga image buffer
+ * count: size of buf in bytes
+ * Returns # of bytes transferred or -ENOBUFS if the all the buffers are in use
+ * or if the service queue is full. Never returns 0.
+ */
+static int s10_send_buf(struct fpga_manager *mgr, const char *buf, size_t count)
+{
+	struct s10_priv *priv = mgr->priv;
+	struct device *dev = priv->client.dev;
+	void *svc_buf;
+	size_t xfer_sz;
+	int ret;
+	uint i;
+
+	/* get/lock a buffer that that's not being used */
+	for (i = 0; i < NUM_SVC_BUFS; i++)
+		if (!test_and_set_bit_lock(SVC_BUF_LOCK,
+					   &priv->svc_bufs[i].lock))
+			break;
+
+	if (i == NUM_SVC_BUFS)
+		return -ENOBUFS;
+
+	xfer_sz = count < SVC_BUF_SIZE ? count : SVC_BUF_SIZE;
+
+	svc_buf = priv->svc_bufs[i].buf;
+	memcpy(svc_buf, buf, xfer_sz);
+	ret = s10_svc_send_msg(priv, COMMAND_RECONFIG_DATA_SUBMIT,
+			       svc_buf, xfer_sz);
+	if (ret < 0) {
+		dev_err(dev,
+			"Error while sending data to service layer (%d)", ret);
+		clear_bit_unlock(SVC_BUF_LOCK, &priv->svc_bufs[i].lock);
+		return ret;
+	}
+
+	return xfer_sz;
+}
+
+/*
+ * Send a FPGA image to privileged layers to write to the FPGA.  When done
+ * sending, free all service layer buffers we allocated in write_init.
+ */
+static int s10_ops_write(struct fpga_manager *mgr, const char *buf,
+			 size_t count)
+{
+	struct s10_priv *priv = mgr->priv;
+	struct device *dev = priv->client.dev;
+	long wait_status;
+	int sent = 0;
+	int ret = 0;
+
+	/*
+	 * Loop waiting for buffers to be returned.  When a buffer is returned,
+	 * reuse it to send more data or free if if all data has been sent.
+	 */
+	while (count > 0 || s10_free_buffer_count(mgr) != NUM_SVC_BUFS) {
+		reinit_completion(&priv->status_return_completion);
+
+		if (count > 0) {
+			sent = s10_send_buf(mgr, buf, count);
+			if (sent < 0)
+				continue;
+
+			count -= sent;
+			buf += sent;
+		} else {
+			if (s10_free_buffers(mgr))
+				return 0;
+
+			ret = s10_svc_send_msg(
+				priv, COMMAND_RECONFIG_DATA_CLAIM,
+				NULL, 0);
+			if (ret < 0)
+				break;
+		}
+
+		/*
+		 * If callback hasn't already happened, wait for buffers to be
+		 * returned from service layer
+		 */
+		wait_status = 1; /* not timed out */
+		if (!priv->status)
+			wait_status = wait_for_completion_interruptible_timeout(
+				&priv->status_return_completion,
+				S10_BUFFER_TIMEOUT);
+
+		if (test_and_clear_bit(SVC_STATUS_RECONFIG_BUFFER_DONE,
+				       &priv->status) ||
+		    test_and_clear_bit(SVC_STATUS_RECONFIG_BUFFER_SUBMITTED,
+				       &priv->status)) {
+			ret = 0;
+			continue;
+		}
+
+		if (test_and_clear_bit(SVC_STATUS_RECONFIG_ERROR,
+				       &priv->status)) {
+			dev_err(dev, "ERROR - giving up - SVC_STATUS_RECONFIG_ERROR\n");
+			ret = -EFAULT;
+			break;
+		}
+
+		if (!wait_status) {
+			dev_err(dev, "timeout waiting for svc layer buffers\n");
+			ret = -ETIMEDOUT;
+			break;
+		}
+		if (wait_status < 0) {
+			ret = wait_status;
+			dev_err(dev,
+				"error (%d) waiting for svc layer buffers\n",
+				ret);
+			break;
+		}
+	}
+
+	if (!s10_free_buffers(mgr))
+		dev_err(dev, "%s not all buffers were freed\n", __func__);
+
+	return ret;
+}
+
+static int s10_ops_write_complete(struct fpga_manager *mgr,
+				  struct fpga_image_info *info)
+{
+	struct s10_priv *priv = mgr->priv;
+	struct device *dev = priv->client.dev;
+	unsigned long timeout;
+	int ret;
+
+	timeout = usecs_to_jiffies(info->config_complete_timeout_us);
+
+	do {
+		reinit_completion(&priv->status_return_completion);
+
+		ret = s10_svc_send_msg(priv, COMMAND_RECONFIG_STATUS, NULL, 0);
+		if (ret < 0)
+			break;
+
+		ret = wait_for_completion_interruptible_timeout(
+			&priv->status_return_completion, timeout);
+		if (!ret) {
+			dev_err(dev,
+				"timeout waiting for RECONFIG_COMPLETED\n");
+			ret = -ETIMEDOUT;
+			break;
+		}
+		if (ret < 0) {
+			dev_err(dev,
+				"error (%d) waiting for RECONFIG_COMPLETED\n",
+				ret);
+			break;
+		}
+		/* Not error or timeout, so ret is # of jiffies until timeout */
+		timeout = ret;
+		ret = 0;
+
+		if (test_and_clear_bit(SVC_STATUS_RECONFIG_COMPLETED,
+				       &priv->status))
+			break;
+
+		if (test_and_clear_bit(SVC_STATUS_RECONFIG_ERROR,
+				       &priv->status)) {
+			dev_err(dev, "ERROR - giving up - SVC_STATUS_RECONFIG_ERROR\n");
+			ret = -EFAULT;
+			break;
+		}
+	} while (1);
+
+	stratix10_svc_done(priv->chan);
+
+	return ret;
+}
+
+static enum fpga_mgr_states s10_ops_state(struct fpga_manager *mgr)
+{
+	return FPGA_MGR_STATE_UNKNOWN;
+}
+
+static const struct fpga_manager_ops s10_ops = {
+	.state = s10_ops_state,
+	.write_init = s10_ops_write_init,
+	.write = s10_ops_write,
+	.write_complete = s10_ops_write_complete,
+};
+
+static int s10_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct s10_priv *priv;
+	struct fpga_manager *mgr;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->client.dev = dev;
+	priv->client.receive_cb = s10_receive_callback;
+	priv->client.priv = priv;
+
+	priv->chan = stratix10_svc_request_channel_byname(&priv->client,
+							  SVC_CLIENT_FPGA);
+	if (IS_ERR(priv->chan)) {
+		dev_err(dev, "couldn't get service channel (%s)\n",
+			SVC_CLIENT_FPGA);
+		return PTR_ERR(priv->chan);
+	}
+
+	init_completion(&priv->status_return_completion);
+
+	mgr = fpga_mgr_create(dev, "Stratix10 SOC FPGA Manager",
+			      &s10_ops, priv);
+	if (!mgr) {
+		dev_err(dev, "unable to create FPGA manager\n");
+		ret = -ENOMEM;
+		goto probe_err;
+	}
+
+	ret = fpga_mgr_register(mgr);
+	if (ret) {
+		dev_err(dev, "unable to register FPGA manager\n");
+		fpga_mgr_free(mgr);
+		goto probe_err;
+	}
+
+	platform_set_drvdata(pdev, mgr);
+	return ret;
+
+probe_err:
+	stratix10_svc_free_channel(priv->chan);
+	return ret;
+}
+
+static int s10_remove(struct platform_device *pdev)
+{
+	struct fpga_manager *mgr = platform_get_drvdata(pdev);
+	struct s10_priv *priv = mgr->priv;
+
+	fpga_mgr_unregister(mgr);
+	stratix10_svc_free_channel(priv->chan);
+
+	return 0;
+}
+
+static const struct of_device_id s10_of_match[] = {
+	{ .compatible = "intel,stratix10-soc-fpga-mgr", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, s10_of_match);
+
+static struct platform_driver s10_driver = {
+	.probe = s10_probe,
+	.remove = s10_remove,
+	.driver = {
+		.name	= "Stratix10 SoC FPGA manager",
+		.of_match_table = of_match_ptr(s10_of_match),
+	},
+};
+
+static int __init s10_init(void)
+{
+	struct device_node *fw_np;
+	struct device_node *np;
+	int ret;
+
+	fw_np = of_find_node_by_name(NULL, "svc");
+	if (!fw_np)
+		return -ENODEV;
+
+	np = of_find_matching_node(fw_np, s10_of_match);
+	if (!np) {
+		of_node_put(fw_np);
+		return -ENODEV;
+	}
+
+	of_node_put(np);
+	ret = of_platform_populate(fw_np, s10_of_match, NULL, NULL);
+	of_node_put(fw_np);
+	if (ret)
+		return ret;
+
+	return platform_driver_register(&s10_driver);
+}
+
+static void __exit s10_exit(void)
+{
+	return platform_driver_unregister(&s10_driver);
+}
+
+module_init(s10_init);
+module_exit(s10_exit);
+
+MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
+MODULE_DESCRIPTION("Intel Stratix 10 SOC FPGA Manager");
+MODULE_LICENSE("GPL v2");