firmware: add Intel Stratix10 remote system update driver

The Intel Remote System Update (RSU) driver exposes interfaces access
through the Intel Service Layer to user space via sysfs interface.
The RSU interfaces report and control some of the optional RSU features
on Intel Stratix 10 SoC.

The RSU feature provides a way for customers to update the boot
configuration of a Intel Stratix 10 SoC device with significantly reduced
risk of corrupting the bitstream storage and bricking the system.

Signed-off-by: Richard Gong <richard.gong@intel.com>
Reviewed-by: Alan Tull <atull@kernel.org>
Link: https://lore.kernel.org/r/1567516701-26026-3-git-send-email-richard.gong@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 470 insertions, 0 deletions

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index ba8d3d0ef32c..c853a17c3f31 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -216,6 +216,24 @@ config INTEL_STRATIX10_SERVICE
 
           Say Y here if you want Stratix10 service layer support.
 
+config INTEL_STRATIX10_RSU
+        tristate "Intel Stratix10 Remote System Update"
+        depends on INTEL_STRATIX10_SERVICE
+        help
+          The Intel Remote System Update (RSU) driver exposes interfaces
+          access through the Intel Service Layer to user space via sysfs
+          device attribute nodes. The RSU interfaces report/control some of
+          the optional RSU features of the Stratix 10 SoC FPGA.
+
+          The RSU provides a way for customers to update the boot
+          configuration of a Stratix 10 SoC device with significantly reduced
+          risk of corrupting the bitstream storage and bricking the system.
+
+          Enable RSU support if you are using an Intel SoC FPGA with the RSU
+          feature enabled and you want Linux user space control.
+
+          Say Y here if you want Intel RSU support.
+
 config QCOM_SCM
         bool
         depends on ARM || ARM64
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 3fa0b34eb72f..d04d5fc4f915 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_EDD)		+= edd.o
 obj-$(CONFIG_EFI_PCDP)          += pcdp.o
 obj-$(CONFIG_DMIID)             += dmi-id.o
 obj-$(CONFIG_INTEL_STRATIX10_SERVICE) += stratix10-svc.o
+obj-$(CONFIG_INTEL_STRATIX10_RSU)     += stratix10-rsu.o
 obj-$(CONFIG_ISCSI_IBFT_FIND)   += iscsi_ibft_find.o
 obj-$(CONFIG_ISCSI_IBFT)        += iscsi_ibft.o
 obj-$(CONFIG_FIRMWARE_MEMMAP)   += memmap.o
diff --git a/drivers/firmware/stratix10-rsu.c b/drivers/firmware/stratix10-rsu.c
new file mode 100644
index 000000000000..bb008c019920
--- /dev/null
+++ b/drivers/firmware/stratix10-rsu.c
@@ -0,0 +1,451 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018-2019, Intel Corporation
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/bitfield.h>
+#include <linux/completion.h>
+#include <linux/kobject.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/firmware/intel/stratix10-svc-client.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+
+#define RSU_STATE_MASK                  GENMASK_ULL(31, 0)
+#define RSU_VERSION_MASK                GENMASK_ULL(63, 32)
+#define RSU_ERROR_LOCATION_MASK         GENMASK_ULL(31, 0)
+#define RSU_ERROR_DETAIL_MASK           GENMASK_ULL(63, 32)
+#define RSU_FW_VERSION_MASK             GENMASK_ULL(15, 0)
+
+#define RSU_TIMEOUT     (msecs_to_jiffies(SVC_RSU_REQUEST_TIMEOUT_MS))
+
+#define INVALID_RETRY_COUNTER           0xFFFFFFFF
+
+typedef void (*rsu_callback)(struct stratix10_svc_client *client,
+                             struct stratix10_svc_cb_data *data);
+/**
+ * struct stratix10_rsu_priv - rsu data structure
+ * @chan: pointer to the allocated service channel
+ * @client: active service client
+ * @completion: state for callback completion
+ * @lock: a mutex to protect callback completion state
+ * @status.current_image: address of image currently running in flash
+ * @status.fail_image: address of failed image in flash
+ * @status.version: the version number of RSU firmware
+ * @status.state: the state of RSU system
+ * @status.error_details: error code
+ * @status.error_location: the error offset inside the image that failed
+ * @retry_counter: the current image's retry counter
+ */
+struct stratix10_rsu_priv {
+        struct stratix10_svc_chan *chan;
+        struct stratix10_svc_client client;
+        struct completion completion;
+        struct mutex lock;
+        struct {
+                unsigned long current_image;
+                unsigned long fail_image;
+                unsigned int version;
+                unsigned int state;
+                unsigned int error_details;
+                unsigned int error_location;
+        } status;
+        unsigned int retry_counter;
+};
+
+/**
+ * rsu_status_callback() - Status callback from Intel Service Layer
+ * @client: pointer to service client
+ * @data: pointer to callback data structure
+ *
+ * Callback from Intel service layer for RSU status request. Status is
+ * only updated after a system reboot, so a get updated status call is
+ * made during driver probe.
+ */
+static void rsu_status_callback(struct stratix10_svc_client *client,
+                                struct stratix10_svc_cb_data *data)
+{
+        struct stratix10_rsu_priv *priv = client->priv;
+        struct arm_smccc_res *res = (struct arm_smccc_res *)data->kaddr1;
+
+        if (data->status == BIT(SVC_STATUS_RSU_OK)) {
+                priv->status.version = FIELD_GET(RSU_VERSION_MASK,
+                                                 res->a2);
+                priv->status.state = FIELD_GET(RSU_STATE_MASK, res->a2);
+                priv->status.fail_image = res->a1;
+                priv->status.current_image = res->a0;
+                priv->status.error_location =
+                        FIELD_GET(RSU_ERROR_LOCATION_MASK, res->a3);
+                priv->status.error_details =
+                        FIELD_GET(RSU_ERROR_DETAIL_MASK, res->a3);
+        } else {
+                dev_err(client->dev, "COMMAND_RSU_STATUS returned 0x%lX\n",
+                        res->a0);
+                priv->status.version = 0;
+                priv->status.state = 0;
+                priv->status.fail_image = 0;
+                priv->status.current_image = 0;
+                priv->status.error_location = 0;
+                priv->status.error_details = 0;
+        }
+
+        complete(&priv->completion);
+}
+
+/**
+ * rsu_command_callback() - Update callback from Intel Service Layer
+ * @client: pointer to client
+ * @data: pointer to callback data structure
+ *
+ * Callback from Intel service layer for RSU commands.
+ */
+static void rsu_command_callback(struct stratix10_svc_client *client,
+                                 struct stratix10_svc_cb_data *data)
+{
+        struct stratix10_rsu_priv *priv = client->priv;
+
+        if (data->status != BIT(SVC_STATUS_RSU_OK))
+                dev_err(client->dev, "RSU returned status is %i\n",
+                        data->status);
+        complete(&priv->completion);
+}
+
+/**
+ * rsu_retry_callback() - Callback from Intel service layer for getting
+ * the current image's retry counter from firmware
+ * @client: pointer to client
+ * @data: pointer to callback data structure
+ *
+ * Callback from Intel service layer for retry counter, which is used by
+ * user to know how many times the images is still allowed to reload
+ * itself before giving up and starting RSU fail-over flow.
+ */
+static void rsu_retry_callback(struct stratix10_svc_client *client,
+                               struct stratix10_svc_cb_data *data)
+{
+        struct stratix10_rsu_priv *priv = client->priv;
+        unsigned int *counter = (unsigned int *)data->kaddr1;
+
+        if (data->status == BIT(SVC_STATUS_RSU_OK))
+                priv->retry_counter = *counter;
+        else
+                dev_err(client->dev, "Failed to get retry counter %i\n",
+                        data->status);
+
+        complete(&priv->completion);
+}
+
+/**
+ * rsu_send_msg() - send a message to Intel service layer
+ * @priv: pointer to rsu private data
+ * @command: RSU status or update command
+ * @arg: the request argument, the bitstream address or notify status
+ * @callback: function pointer for the callback (status or update)
+ *
+ * Start an Intel service layer transaction to perform the SMC call that
+ * is necessary to get RSU boot log or set the address of bitstream to
+ * boot after reboot.
+ *
+ * Returns 0 on success or -ETIMEDOUT on error.
+ */
+static int rsu_send_msg(struct stratix10_rsu_priv *priv,
+                        enum stratix10_svc_command_code command,
+                        unsigned long arg,
+                        rsu_callback callback)
+{
+        struct stratix10_svc_client_msg msg;
+        int ret;
+
+        mutex_lock(&priv->lock);
+        reinit_completion(&priv->completion);
+        priv->client.receive_cb = callback;
+
+        msg.command = command;
+        if (arg)
+                msg.arg[0] = arg;
+
+        ret = stratix10_svc_send(priv->chan, &msg);
+        if (ret < 0)
+                goto status_done;
+
+        ret = wait_for_completion_interruptible_timeout(&priv->completion,
+                                                        RSU_TIMEOUT);
+        if (!ret) {
+                dev_err(priv->client.dev,
+                        "timeout waiting for SMC call\n");
+                ret = -ETIMEDOUT;
+                goto status_done;
+        } else if (ret < 0) {
+                dev_err(priv->client.dev,
+                        "error %d waiting for SMC call\n", ret);
+                goto status_done;
+        } else {
+                ret = 0;
+        }
+
+status_done:
+        stratix10_svc_done(priv->chan);
+        mutex_unlock(&priv->lock);
+        return ret;
+}
+
+/*
+ * This driver exposes some optional features of the Intel Stratix 10 SoC FPGA.
+ * The sysfs interfaces exposed here are FPGA Remote System Update (RSU)
+ * related. They allow user space software to query the configuration system
+ * status and to request optional reboot behavior specific to Intel FPGAs.
+ */
+
+static ssize_t current_image_show(struct device *dev,
+                                  struct device_attribute *attr, char *buf)
+{
+        struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
+
+        if (!priv)
+                return -ENODEV;
+
+        return sprintf(buf, "0x%08lx\n", priv->status.current_image);
+}
+
+static ssize_t fail_image_show(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+        struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
+
+        if (!priv)
+                return -ENODEV;
+
+        return sprintf(buf, "0x%08lx\n", priv->status.fail_image);
+}
+
+static ssize_t version_show(struct device *dev, struct device_attribute *attr,
+                            char *buf)
+{
+        struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
+
+        if (!priv)
+                return -ENODEV;
+
+        return sprintf(buf, "0x%08x\n", priv->status.version);
+}
+
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+                          char *buf)
+{
+        struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
+
+        if (!priv)
+                return -ENODEV;
+
+        return sprintf(buf, "0x%08x\n", priv->status.state);
+}
+
+static ssize_t error_location_show(struct device *dev,
+                                   struct device_attribute *attr, char *buf)
+{
+        struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
+
+        if (!priv)
+                return -ENODEV;
+
+        return sprintf(buf, "0x%08x\n", priv->status.error_location);
+}
+
+static ssize_t error_details_show(struct device *dev,
+                                  struct device_attribute *attr, char *buf)
+{
+        struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
+
+        if (!priv)
+                return -ENODEV;
+
+        return sprintf(buf, "0x%08x\n", priv->status.error_details);
+}
+
+static ssize_t retry_counter_show(struct device *dev,
+                                  struct device_attribute *attr, char *buf)
+{
+        struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
+
+        if (!priv)
+                return -ENODEV;
+
+        return sprintf(buf, "0x%08x\n", priv->retry_counter);
+}
+
+static ssize_t reboot_image_store(struct device *dev,
+                                  struct device_attribute *attr,
+                                  const char *buf, size_t count)
+{
+        struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
+        unsigned long address;
+        int ret;
+
+        if (priv == 0)
+                return -ENODEV;
+
+        ret = kstrtoul(buf, 0, &address);
+        if (ret)
+                return ret;
+
+        ret = rsu_send_msg(priv, COMMAND_RSU_UPDATE,
+                           address, rsu_command_callback);
+        if (ret) {
+                dev_err(dev, "Error, RSU update returned %i\n", ret);
+                return ret;
+        }
+
+        return count;
+}
+
+static ssize_t notify_store(struct device *dev,
+                            struct device_attribute *attr,
+                            const char *buf, size_t count)
+{
+        struct stratix10_rsu_priv *priv = dev_get_drvdata(dev);
+        unsigned long status;
+        int ret;
+
+        if (priv == 0)
+                return -ENODEV;
+
+        ret = kstrtoul(buf, 0, &status);
+        if (ret)
+                return ret;
+
+        ret = rsu_send_msg(priv, COMMAND_RSU_NOTIFY,
+                           status, rsu_command_callback);
+        if (ret) {
+                dev_err(dev, "Error, RSU notify returned %i\n", ret);
+                return ret;
+        }
+
+        /* to get the updated state */
+        ret = rsu_send_msg(priv, COMMAND_RSU_STATUS,
+                           0, rsu_status_callback);
+        if (ret) {
+                dev_err(dev, "Error, getting RSU status %i\n", ret);
+                return ret;
+        }
+
+        /* only 19.3 or late version FW supports retry counter feature */
+        if (FIELD_GET(RSU_FW_VERSION_MASK, priv->status.version)) {
+                ret = rsu_send_msg(priv, COMMAND_RSU_RETRY,
+                                   0, rsu_retry_callback);
+                if (ret) {
+                        dev_err(dev,
+                                "Error, getting RSU retry %i\n", ret);
+                        return ret;
+                }
+        }
+
+        return count;
+}
+
+static DEVICE_ATTR_RO(current_image);
+static DEVICE_ATTR_RO(fail_image);
+static DEVICE_ATTR_RO(state);
+static DEVICE_ATTR_RO(version);
+static DEVICE_ATTR_RO(error_location);
+static DEVICE_ATTR_RO(error_details);
+static DEVICE_ATTR_RO(retry_counter);
+static DEVICE_ATTR_WO(reboot_image);
+static DEVICE_ATTR_WO(notify);
+
+static struct attribute *rsu_attrs[] = {
+        &dev_attr_current_image.attr,
+        &dev_attr_fail_image.attr,
+        &dev_attr_state.attr,
+        &dev_attr_version.attr,
+        &dev_attr_error_location.attr,
+        &dev_attr_error_details.attr,
+        &dev_attr_retry_counter.attr,
+        &dev_attr_reboot_image.attr,
+        &dev_attr_notify.attr,
+        NULL
+};
+
+ATTRIBUTE_GROUPS(rsu);
+
+static int stratix10_rsu_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct stratix10_rsu_priv *priv;
+        int ret;
+
+        priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        priv->client.dev = dev;
+        priv->client.receive_cb = NULL;
+        priv->client.priv = priv;
+        priv->status.current_image = 0;
+        priv->status.fail_image = 0;
+        priv->status.error_location = 0;
+        priv->status.error_details = 0;
+        priv->status.version = 0;
+        priv->status.state = 0;
+        priv->retry_counter = INVALID_RETRY_COUNTER;
+
+        mutex_init(&priv->lock);
+        priv->chan = stratix10_svc_request_channel_byname(&priv->client,
+                                                          SVC_CLIENT_RSU);
+        if (IS_ERR(priv->chan)) {
+                dev_err(dev, "couldn't get service channel %s\n",
+                        SVC_CLIENT_RSU);
+                return PTR_ERR(priv->chan);
+        }
+
+        init_completion(&priv->completion);
+        platform_set_drvdata(pdev, priv);
+
+        /* get the initial state from firmware */
+        ret = rsu_send_msg(priv, COMMAND_RSU_STATUS,
+                           0, rsu_status_callback);
+        if (ret) {
+                dev_err(dev, "Error, getting RSU status %i\n", ret);
+                stratix10_svc_free_channel(priv->chan);
+        }
+
+        /* only 19.3 or late version FW supports retry counter feature */
+        if (FIELD_GET(RSU_FW_VERSION_MASK, priv->status.version)) {
+                ret = rsu_send_msg(priv, COMMAND_RSU_RETRY, 0,
+                                   rsu_retry_callback);
+                if (ret) {
+                        dev_err(dev,
+                                "Error, getting RSU retry %i\n", ret);
+                        stratix10_svc_free_channel(priv->chan);
+                }
+        }
+
+        return ret;
+}
+
+static int stratix10_rsu_remove(struct platform_device *pdev)
+{
+        struct stratix10_rsu_priv *priv = platform_get_drvdata(pdev);
+
+        stratix10_svc_free_channel(priv->chan);
+        return 0;
+}
+
+static struct platform_driver stratix10_rsu_driver = {
+        .probe = stratix10_rsu_probe,
+        .remove = stratix10_rsu_remove,
+        .driver = {
+                .name = "stratix10-rsu",
+                .dev_groups = rsu_groups,
+        },
+};
+
+module_platform_driver(stratix10_rsu_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel Remote System Update Driver");
+MODULE_AUTHOR("Richard Gong <richard.gong@intel.com>");