[PATCH 2/3] EDAC/amd64: Only remove instances that exist

[Yazen Ghannam <Yazen.Ghannam@amd.com>]

From: Yazen Ghannam <yazen.ghannam@amd.com>

An instance may have failed probing because the probed node did not have
DRAM installed. When the module is unloaded we'll get a WARNing when
we try to remove a non-existent instance.

Save a bitmask of enabled instances with a bit for each node.

Only try to remove an instance if it was successfully enabled in the
first place.

Cc: <stable@vger.kernel.org> # 4.14.x
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
---
 drivers/edac/amd64_edac.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index af0ce9aa8d24..054086b19c6c 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -13,6 +13,8 @@ module_param(report_gart_errors, int, 0644);
 static int ecc_enable_override;
 module_param(ecc_enable_override, int, 0644);
 
+static unsigned long int enabled_instances;
+
 static struct msr __percpu *msrs;
 
 /* Per-node stuff */
@@ -3366,6 +3368,7 @@ static int probe_one_instance(unsigned int nid)
 		goto err_enable;
 	}
 
+	set_bit(nid, &enabled_instances);
 	return ret;
 
 err_enable:
@@ -3383,6 +3386,9 @@ static void remove_one_instance(unsigned int nid)
 	struct mem_ctl_info *mci;
 	struct amd64_pvt *pvt;
 
+	if (!test_bit(nid, &enabled_instances))
+		return;
+
 	mci = find_mci_by_dev(&F3->dev);
 	WARN_ON(!mci);
 
@@ -3405,6 +3411,8 @@ static void remove_one_instance(unsigned int nid)
 
 	kfree(pvt);
 	edac_mc_free(mci);
+
+	clear_bit(nid, &enabled_instances);
 }
 
 static void setup_pci_device(void)
-- 
2.14.1