dmaengine: idxd: add command status to idxd sysfs attribute

Export admin command status to sysfs attribute in order to allow user to
retrieve configuration error. Allows user tooling to retrieve the command
error and provide more user friendly error messages.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/159865278770.29455.8026892329182750127.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd
index a2bc4afbe3080bf95bdbcc7049ceba26ad6bed29..b4418388093554d4933ea0265e4794ed6acc43e5 100644 (file)
--- a/Documentation/ABI/stable/sysfs-driver-dma-idxd
+++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd
@@ -116,6 +116,12 @@ Description:    The maximum number of bandwidth tokens that may be in use at
                one time by operations that access low bandwidth memory in the
                device.
 
+What:          /sys/bus/dsa/devices/dsa<m>/cmd_status
+Date:          Aug 28, 2020
+KernelVersion: 5.10.0
+Contact:       dmaengine@vger.kernel.org
+Description:   The last executed device administrative command's status/error.
+
 What:           /sys/bus/dsa/devices/wq<m>.<n>/group_id
 Date:           Oct 25, 2019
 KernelVersion:  5.6.0

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 00dab1465ca3b6ced58cf9c6d264226dc7501593..22f6c871baa9cea720bcbec7c059e69da27899be 100644 (file)
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -368,6 +368,7 @@ static void idxd_cmd_exec(struct idxd_device *idxd, int cmd_code, u32 operand,
        dev_dbg(&idxd->pdev->dev, "%s: sending cmd: %#x op: %#x\n",
                __func__, cmd_code, operand);
 
+       idxd->cmd_status = 0;
        __set_bit(IDXD_FLAG_CMD_RUNNING, &idxd->flags);
        idxd->cmd_done = &done;
        iowrite32(cmd.bits, idxd->reg_base + IDXD_CMD_OFFSET);
@@ -379,8 +380,11 @@ static void idxd_cmd_exec(struct idxd_device *idxd, int cmd_code, u32 operand,
        spin_unlock_irqrestore(&idxd->dev_lock, flags);
        wait_for_completion(&done);
        spin_lock_irqsave(&idxd->dev_lock, flags);
-       if (status)
+       if (status) {
                *status = ioread32(idxd->reg_base + IDXD_CMDSTS_OFFSET);
+               idxd->cmd_status = *status & GENMASK(7, 0);
+       }
+
        __clear_bit(IDXD_FLAG_CMD_RUNNING, &idxd->flags);
        /* Wake up other pending commands */
        wake_up(&idxd->cmd_waitq);

diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index e8bec6eb9f7e3be189e81175d31e5866d6129786..c64df197e724854401690e96b48f5b328df4ff53 100644 (file)
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -156,6 +156,7 @@ struct idxd_device {
        unsigned long flags;
        int id;
        int major;
+       u8 cmd_status;
 
        struct pci_dev *pdev;
        void __iomem *reg_base;

diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index e6284cb78a4c5d6ff563b0e7c77571d6c30fe690..07a5db06a29ad3738eab05717933b674f2fa0769 100644 (file)
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -1402,6 +1402,15 @@ static ssize_t cdev_major_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(cdev_major);
 
+static ssize_t cmd_status_show(struct device *dev,
+                              struct device_attribute *attr, char *buf)
+{
+       struct idxd_device *idxd = container_of(dev, struct idxd_device, conf_dev);
+
+       return sprintf(buf, "%#x\n", idxd->cmd_status);
+}
+static DEVICE_ATTR_RO(cmd_status);
+
 static struct attribute *idxd_device_attributes[] = {
        &dev_attr_version.attr,
        &dev_attr_max_groups.attr,
@@ -1420,6 +1429,7 @@ static struct attribute *idxd_device_attributes[] = {
        &dev_attr_max_tokens.attr,
        &dev_attr_token_limit.attr,
        &dev_attr_cdev_major.attr,
+       &dev_attr_cmd_status.attr,
        NULL,
 };