diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/fpga/dfl-afu-main.c | 79 |
1 files changed, 78 insertions, 1 deletions
diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c index a38d6a825e7e..d36b3e9f3984 100644 --- a/drivers/fpga/dfl-afu-main.c +++ b/drivers/fpga/dfl-afu-main.c @@ -16,6 +16,7 @@ #include <linux/kernel.h> #include <linux/module.h> +#include <linux/fpga-dfl.h> #include "dfl.h" @@ -87,6 +88,41 @@ static int port_disable(struct platform_device *pdev) return 0; } +/* + * This function resets the FPGA Port and its accelerator (AFU) by function + * __port_disable and __port_enable (set port soft reset bit and then clear + * it). Userspace can do Port reset at any time, e.g. during DMA or Partial + * Reconfiguration. But it should never cause any system level issue, only + * functional failure (e.g. DMA or PR operation failure) and be recoverable + * from the failure. + * + * Note: the accelerator (AFU) is not accessible when its port is in reset + * (disabled). Any attempts on MMIO access to AFU while in reset, will + * result errors reported via port error reporting sub feature (if present). + */ +static int __port_reset(struct platform_device *pdev) +{ + int ret; + + ret = port_disable(pdev); + if (!ret) + port_enable(pdev); + + return ret; +} + +static int port_reset(struct platform_device *pdev) +{ + struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); + int ret; + + mutex_lock(&pdata->lock); + ret = __port_reset(pdev); + mutex_unlock(&pdata->lock); + + return ret; +} + static int port_get_id(struct platform_device *pdev) { void __iomem *base; @@ -96,23 +132,63 @@ static int port_get_id(struct platform_device *pdev) return FIELD_GET(PORT_CAP_PORT_NUM, readq(base + PORT_HDR_CAP)); } +static ssize_t +id_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + int id = port_get_id(to_platform_device(dev)); + + return scnprintf(buf, PAGE_SIZE, "%d\n", id); +} +static DEVICE_ATTR_RO(id); + +static const struct attribute *port_hdr_attrs[] = { + &dev_attr_id.attr, + NULL, +}; + static int port_hdr_init(struct platform_device *pdev, struct dfl_feature *feature) { dev_dbg(&pdev->dev, "PORT HDR Init.\n"); - return 0; + port_reset(pdev); + + return sysfs_create_files(&pdev->dev.kobj, port_hdr_attrs); } static void port_hdr_uinit(struct platform_device *pdev, struct dfl_feature *feature) { dev_dbg(&pdev->dev, "PORT HDR UInit.\n"); + + sysfs_remove_files(&pdev->dev.kobj, port_hdr_attrs); +} + +static long +port_hdr_ioctl(struct platform_device *pdev, struct dfl_feature *feature, + unsigned int cmd, unsigned long arg) +{ + long ret; + + switch (cmd) { + case DFL_FPGA_PORT_RESET: + if (!arg) + ret = port_reset(pdev); + else + ret = -EINVAL; + break; + default: + dev_dbg(&pdev->dev, "%x cmd not handled", cmd); + ret = -ENODEV; + } + + return ret; } static const struct dfl_feature_ops port_hdr_ops = { .init = port_hdr_init, .uinit = port_hdr_uinit, + .ioctl = port_hdr_ioctl, }; static struct dfl_feature_driver port_feature_drvs[] = { @@ -154,6 +230,7 @@ static int afu_release(struct inode *inode, struct file *filp) pdata = dev_get_platdata(&pdev->dev); + port_reset(pdev); dfl_feature_dev_use_end(pdata); return 0; |