[PATCH 10/11] EDAC/ghes: Create an own device for each mci

[Robert Richter]

Each edac mc must have a unique device for identification (see
add_mc_to_global_list()). This 1:1 mapping between parent device and
mci is a limitation for supporting multiple instances created by the
ghes driver. Solve this by creating an own device in between of the
ghes parent and the mci struct, this allows a 1:n mapping between
both.

Implement this using a platform device as this is the least possible
effort to create and free a device. It shows up nicely in sysfs:

 # find /sys/ -name ghes_mc*
 /sys/devices/platform/GHES.0/ghes_mc.1
 /sys/devices/platform/GHES.0/ghes_mc.0
 /sys/bus/platform/devices/ghes_mc.1
 /sys/bus/platform/devices/ghes_mc.0

Signed-off-by: Robert Richter <rrichter@xxxxxxxxxxx>
---
 drivers/edac/ghes_edac.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c
index cd61b8ae49f6..64220397296e 100644
--- a/drivers/edac/ghes_edac.c
+++ b/drivers/edac/ghes_edac.c
@@ -539,6 +539,8 @@ static struct acpi_platform_list plat_list[] = {
 static struct mem_ctl_info *ghes_mc_create(struct device *dev, int mc_idx,
 					int num_dimm)
 {
+	struct platform_device_info pdevinfo;
+	struct platform_device *pdev;
 	struct edac_mc_layer layers[1];
 	struct mem_ctl_info *mci;
 	struct ghes_mci *pvt;
@@ -547,13 +549,23 @@ static struct mem_ctl_info *ghes_mc_create(struct device *dev, int mc_idx,
 	layers[0].size = num_dimm;
 	layers[0].is_virt_csrow = true;
 
+	pdevinfo	= (struct platform_device_info){
+		.parent	= dev,
+		.name	= "ghes_mc",
+		.id	= mc_idx,
+	};
+
+	pdev = platform_device_register_full(&pdevinfo);
+	if (IS_ERR(pdev))
+		goto fail;
+
 	mci = edac_mc_alloc(mc_idx, ARRAY_SIZE(layers), layers, sizeof(*pvt));
 	if (!mci)
-		return NULL;
+		goto fail;
 
 	pvt = mci->pvt_info;
 
-	mci->pdev = dev;
+	mci->pdev = &pdev->dev;
 	mci->mtype_cap = MEM_FLAG_EMPTY;
 	mci->edac_ctl_cap = EDAC_FLAG_NONE;
 	mci->edac_cap = EDAC_FLAG_NONE;
@@ -562,6 +574,11 @@ static struct mem_ctl_info *ghes_mc_create(struct device *dev, int mc_idx,
 	mci->dev_name = "ghes";
 
 	return mci;
+
+fail:
+	platform_device_unregister(pdev);
+
+	return NULL;
 }
 
 static int ghes_mc_add_or_free(struct mem_ctl_info *mci,
@@ -573,6 +590,7 @@ static int ghes_mc_add_or_free(struct mem_ctl_info *mci,
 	rc = edac_mc_add_mc(mci);
 	if (rc < 0) {
 		ghes_dimm_release(dimms);
+		platform_device_unregister(to_platform_device(mci->pdev));
 		edac_mc_free(mci);
 		return rc;
 	}
@@ -609,8 +627,10 @@ static void ghes_mc_free(void)
 		return;
 
 	mci = edac_mc_del_mc(mci->pdev);
-	if (mci)
+	if (mci) {
+		platform_device_unregister(to_platform_device(mci->pdev));
 		edac_mc_free(mci);
+	}
 }
 
 static int ghes_edac_register_fake(struct device *dev)
-- 
2.20.1