ata: ahci: Add sysfs attribute to show remapped NVMe device count

Add a new sysfs attribute to show how many NVMe devices are remapped.

Userspace like distro installer can use this info to ask user to change
the BIOS setting.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index ad0185c..f23a992 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1495,7 +1495,7 @@ static irqreturn_t ahci_thunderx_irq_handler(int irq, void *dev_instance)
 static void ahci_remap_check(struct pci_dev *pdev, int bar,
                struct ahci_host_priv *hpriv)
 {
-       int i, count = 0;
+       int i;
        u32 cap;
 
        /*
@@ -1516,13 +1516,14 @@ static void ahci_remap_check(struct pci_dev *pdev, int bar,
                        continue;
 
                /* We've found a remapped device */
-               count++;
+               hpriv->remapped_nvme++;
        }
 
-       if (!count)
+       if (!hpriv->remapped_nvme)
                return;
 
-       dev_warn(&pdev->dev, "Found %d remapped NVMe devices.\n", count);
+       dev_warn(&pdev->dev, "Found %u remapped NVMe devices.\n",
+                hpriv->remapped_nvme);
        dev_warn(&pdev->dev,
                 "Switch your BIOS from RAID to AHCI mode to use them.\n");
 
@@ -1642,6 +1643,18 @@ static void ahci_intel_pcs_quirk(struct pci_dev *pdev, struct ahci_host_priv *hp
        }
 }
 
+static ssize_t remapped_nvme_show(struct device *dev,
+                                 struct device_attribute *attr,
+                                 char *buf)
+{
+       struct ata_host *host = dev_get_drvdata(dev);
+       struct ahci_host_priv *hpriv = host->private_data;
+
+       return sprintf(buf, "%u\n", hpriv->remapped_nvme);
+}
+
+static DEVICE_ATTR_RO(remapped_nvme);
+
 static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
        unsigned int board_id = ent->driver_data;
@@ -1745,6 +1758,10 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
        /* detect remapped nvme devices */
        ahci_remap_check(pdev, ahci_pci_bar, hpriv);
 
+       sysfs_add_file_to_group(&pdev->dev.kobj,
+                               &dev_attr_remapped_nvme.attr,
+                               NULL);
+
        /* must set flag prior to save config in order to take effect */
        if (ahci_broken_devslp(pdev))
                hpriv->flags |= AHCI_HFLAG_NO_DEVSLP;
@@ -1896,6 +1913,9 @@ static void ahci_shutdown_one(struct pci_dev *pdev)
 
 static void ahci_remove_one(struct pci_dev *pdev)
 {
+       sysfs_remove_file_from_group(&pdev->dev.kobj,
+                                    &dev_attr_remapped_nvme.attr,
+                                    NULL);
        pm_runtime_get_noresume(&pdev->dev);
        ata_pci_remove_one(pdev);
 }

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 3dbf398..d991dd4 100644 (file)
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -336,6 +336,7 @@ struct ahci_host_priv {
        u32                     em_loc; /* enclosure management location */
        u32                     em_buf_sz;      /* EM buffer size in byte */
        u32                     em_msg_type;    /* EM message type */
+       u32                     remapped_nvme;  /* NVMe remapped device count */
        bool                    got_runtime_pm; /* Did we do pm_runtime_get? */
        struct clk              *clks[AHCI_MAX_CLKS]; /* Optional */
        struct reset_control    *rsts;          /* Optional */