[PATCH 5/7] fpga: dfl: fme: add interrupt support for global error reporting

[Xu Yilun <yilun.xu@intel.com>]

Error reporting interrupt is very useful to notify users that some
errors are detected by the hardware. Once users are notified, they
could query hardware logged error states, no need to continuously
poll on these states.

This patch follows the common DFL interrupt notification and handling
mechanism. And it implements two ioctls below for user to query
hardware capability and set/unset interrupt triggers.

 Ioctls:
 * DFL_FPGA_FME_ERR_GET_INFO
   get fme global error reporting feature info, including num_irqs which
   is used to determine whether/how many interrupts it supports.

 * DFL_FPGA_FME_ERR_SET_IRQ
   set/unset given eventfds as fme error reporting interrupt triggers.

Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
---
 drivers/fpga/dfl-fme-error.c  | 71 +++++++++++++++++++++++++++++++++++++++++++
 drivers/fpga/dfl-fme-main.c   |  6 ++++
 include/uapi/linux/fpga-dfl.h | 27 ++++++++++++++++
 3 files changed, 104 insertions(+)

diff --git a/drivers/fpga/dfl-fme-error.c b/drivers/fpga/dfl-fme-error.c
index f897d41..df5e7b8 100644
--- a/drivers/fpga/dfl-fme-error.c
+++ b/drivers/fpga/dfl-fme-error.c
@@ -16,6 +16,7 @@
  */
 
 #include <linux/uaccess.h>
+#include <linux/fpga-dfl.h>
 
 #include "dfl.h"
 #include "dfl-fme.h"
@@ -348,6 +349,75 @@ static void fme_global_err_uinit(struct platform_device *pdev,
 	fme_err_mask(&pdev->dev, true);
 }
 
+static long
+fme_global_err_get_info(struct platform_device *pdev,
+			struct dfl_feature *feature, unsigned long arg)
+{
+	struct dfl_fpga_fme_err_info info;
+
+	info.flags = 0;
+	info.capability = 0;
+	info.num_irqs = feature->nr_irqs;
+
+	if (copy_to_user((void __user *)arg, &info, sizeof(info)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static long
+fme_global_err_set_irq(struct platform_device *pdev,
+		       struct dfl_feature *feature, unsigned long arg)
+{
+	struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	struct dfl_fpga_irq_set hdr;
+	s32 *fds;
+	long ret;
+
+	if (!feature->nr_irqs)
+		return -ENOENT;
+
+	if (copy_from_user(&hdr, (void __user *)arg, sizeof(hdr)))
+		return -EFAULT;
+
+	if (hdr.flags || (hdr.start + hdr.count > feature->nr_irqs) ||
+	    (hdr.start + hdr.count < hdr.start) || !hdr.count)
+		return -EINVAL;
+
+	fds = memdup_user((void __user *)(arg + sizeof(hdr)),
+			  hdr.count * sizeof(s32));
+	if (IS_ERR(fds))
+		return PTR_ERR(fds);
+
+	mutex_lock(&pdata->lock);
+	ret = dfl_fpga_set_irq_triggers(feature, hdr.start, hdr.count, fds);
+	mutex_unlock(&pdata->lock);
+
+	kfree(fds);
+	return ret;
+}
+
+static long
+fme_global_error_ioctl(struct platform_device *pdev,
+		       struct dfl_feature *feature,
+		       unsigned int cmd, unsigned long arg)
+{
+	long ret = -ENODEV;
+
+	switch (cmd) {
+	case DFL_FPGA_FME_ERR_GET_INFO:
+		ret = fme_global_err_get_info(pdev, feature, arg);
+		break;
+	case DFL_FPGA_FME_ERR_SET_IRQ:
+		ret = fme_global_err_set_irq(pdev, feature, arg);
+		break;
+	default:
+		dev_dbg(&pdev->dev, "%x cmd not handled", cmd);
+	}
+
+	return ret;
+}
+
 const struct dfl_feature_id fme_global_err_id_table[] = {
 	{.id = FME_FEATURE_ID_GLOBAL_ERR,},
 	{0,}
@@ -356,4 +426,5 @@ const struct dfl_feature_id fme_global_err_id_table[] = {
 const struct dfl_feature_ops fme_global_err_ops = {
 	.init = fme_global_err_init,
 	.uinit = fme_global_err_uinit,
+	.ioctl = fme_global_error_ioctl,
 };
diff --git a/drivers/fpga/dfl-fme-main.c b/drivers/fpga/dfl-fme-main.c
index 56d720c..ab3722d 100644
--- a/drivers/fpga/dfl-fme-main.c
+++ b/drivers/fpga/dfl-fme-main.c
@@ -616,11 +616,17 @@ static int fme_release(struct inode *inode, struct file *filp)
 {
 	struct dfl_feature_platform_data *pdata = filp->private_data;
 	struct platform_device *pdev = pdata->dev;
+	struct dfl_feature *feature;
 
 	dev_dbg(&pdev->dev, "Device File Release\n");
 
 	mutex_lock(&pdata->lock);
 	dfl_feature_dev_use_end(pdata);
+
+	if (!dfl_feature_dev_use_count(pdata))
+		dfl_fpga_dev_for_each_feature(pdata, feature)
+			dfl_fpga_set_irq_triggers(feature, 0,
+						  feature->nr_irqs, NULL);
 	mutex_unlock(&pdata->lock);
 
 	return 0;
diff --git a/include/uapi/linux/fpga-dfl.h b/include/uapi/linux/fpga-dfl.h
index 846fc91..c212fa9 100644
--- a/include/uapi/linux/fpga-dfl.h
+++ b/include/uapi/linux/fpga-dfl.h
@@ -228,4 +228,31 @@ struct dfl_fpga_fme_port_pr {
  */
 #define DFL_FPGA_FME_PORT_ASSIGN     _IOW(DFL_FPGA_MAGIC, DFL_FME_BASE + 2, int)
 
+/**
+ * DFL_FPGA_FME_ERR_GET_INFO - _IOR(DFL_FPGA_MAGIC, DFL_FME_BASE + 3,
+ *						struct dfl_fpga_fme_err_info)
+ *
+ * Retrieve information about the fpga fme error reporting private feature.
+ * Driver fills the info in provided struct dfl_fpga_fme_err_info.
+ * Return: 0 on success, -errno on failure.
+ */
+struct dfl_fpga_fme_err_info {
+	/* Output */
+	__u32 flags;		/* Zero for now */
+	__u32 capability;	/* The capability of fme err */
+	__u32 num_irqs;		/* number of irqs fme err supports */
+};
+
+#define DFL_FPGA_FME_ERR_GET_INFO	_IO(DFL_FPGA_MAGIC, DFL_FME_BASE + 3)
+
+/**
+ * DFL_FPGA_FME_ERR_SET_IRQ - _IOW(DFL_FPGA_MAGIC, DFL_FME_BASE + 4,
+ *						struct dfl_fpga_irq_set)
+ *
+ * Set fpga fme error reporting interrupt trigger if evtfds[n] is valid.
+ * Unset related interrupt trigger if evtfds[n] is a negative value.
+ * Return: 0 on success, -errno on failure.
+ */
+#define DFL_FPGA_FME_ERR_SET_IRQ	_IO(DFL_FPGA_MAGIC, DFL_FME_BASE + 4)
+
 #endif /* _UAPI_LINUX_FPGA_DFL_H */
-- 
2.7.4