[PATCH AUTOSEL 4.4 22/22] EDAC/ie31200: Fallback if host bridge device is already initialized

From: Sasha Levin
Date: Fri Aug 21 2020 - 12:24:22 EST


From: Jason Baron <jbaron@xxxxxxxxxx>

[ Upstream commit 709ed1bcef12398ac1a35c149f3e582db04456c2 ]

The Intel uncore driver may claim some of the pci ids from ie31200 which
means that the ie31200 edac driver will not initialize them as part of
pci_register_driver().

Let's add a fallback for this case to 'pci_get_device()' to get a
reference on the device such that it can still be configured. This is
similar in approach to other edac drivers.

Signed-off-by: Jason Baron <jbaron@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Cc: linux-edac <linux-edac@xxxxxxxxxxxxxxx>
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
Link: https://lore.kernel.org/r/1594923911-10885-1-git-send-email-jbaron@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/edac/ie31200_edac.c | 50 ++++++++++++++++++++++++++++++++++---
1 file changed, 47 insertions(+), 3 deletions(-)

diff --git a/drivers/edac/ie31200_edac.c b/drivers/edac/ie31200_edac.c
index 18d77ace4813c..30f83fb6b145a 100644
--- a/drivers/edac/ie31200_edac.c
+++ b/drivers/edac/ie31200_edac.c
@@ -131,6 +131,8 @@
#define IE31200_PAGES(n) (n << (28 - PAGE_SHIFT))

static int nr_channels;
+static struct pci_dev *mci_pdev;
+static int ie31200_registered = 1;

struct ie31200_priv {
void __iomem *window;
@@ -456,12 +458,16 @@ static int ie31200_probe1(struct pci_dev *pdev, int dev_idx)
static int ie31200_init_one(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
- edac_dbg(0, "MC:\n");
+ int rc;

+ edac_dbg(0, "MC:\n");
if (pci_enable_device(pdev) < 0)
return -EIO;
+ rc = ie31200_probe1(pdev, ent->driver_data);
+ if (rc == 0 && !mci_pdev)
+ mci_pdev = pci_dev_get(pdev);

- return ie31200_probe1(pdev, ent->driver_data);
+ return rc;
}

static void ie31200_remove_one(struct pci_dev *pdev)
@@ -470,6 +476,8 @@ static void ie31200_remove_one(struct pci_dev *pdev)
struct ie31200_priv *priv;

edac_dbg(0, "\n");
+ pci_dev_put(mci_pdev);
+ mci_pdev = NULL;
mci = edac_mc_del_mc(&pdev->dev);
if (!mci)
return;
@@ -515,17 +523,53 @@ static struct pci_driver ie31200_driver = {

static int __init ie31200_init(void)
{
+ int pci_rc, i;
+
edac_dbg(3, "MC:\n");
/* Ensure that the OPSTATE is set correctly for POLL or NMI */
opstate_init();

- return pci_register_driver(&ie31200_driver);
+ pci_rc = pci_register_driver(&ie31200_driver);
+ if (pci_rc < 0)
+ goto fail0;
+
+ if (!mci_pdev) {
+ ie31200_registered = 0;
+ for (i = 0; ie31200_pci_tbl[i].vendor != 0; i++) {
+ mci_pdev = pci_get_device(ie31200_pci_tbl[i].vendor,
+ ie31200_pci_tbl[i].device,
+ NULL);
+ if (mci_pdev)
+ break;
+ }
+ if (!mci_pdev) {
+ edac_dbg(0, "ie31200 pci_get_device fail\n");
+ pci_rc = -ENODEV;
+ goto fail1;
+ }
+ pci_rc = ie31200_init_one(mci_pdev, &ie31200_pci_tbl[i]);
+ if (pci_rc < 0) {
+ edac_dbg(0, "ie31200 init fail\n");
+ pci_rc = -ENODEV;
+ goto fail1;
+ }
+ }
+ return 0;
+
+fail1:
+ pci_unregister_driver(&ie31200_driver);
+fail0:
+ pci_dev_put(mci_pdev);
+
+ return pci_rc;
}

static void __exit ie31200_exit(void)
{
edac_dbg(3, "MC:\n");
pci_unregister_driver(&ie31200_driver);
+ if (!ie31200_registered)
+ ie31200_remove_one(mci_pdev);
}

module_init(ie31200_init);
--
2.25.1