libndctl: Unify adding dimms for papr and nfit families

BZ: 
Brew: 

commit daef3a386a9c45105a2c045ddee46600e265939f
Author: Santosh Sivaraj <santosh@fossix.org>
Date:   Thu May 13 11:42:15 2021 +0530

    libndctl: Unify adding dimms for papr and nfit families
    
    In preparation for enabling tests on non-nfit devices, unify both, already very
    similar, functions into one. This will help in adding all attributes needed for
    the unit tests. Since the function doesn't fail if some of the dimm attributes
    are missing, this will work fine on PAPR platforms though only part of the DIMM
    attributes are provided (This doesn't mean that all of the DIMM attributes can
    be missing).
    
    Link: https://lore.kernel.org/r/20210513061218.760322-1-santosh@fossix.org
    Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
    Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

diff --git a/ndctl/lib/libndctl.c b/ndctl/lib/libndctl.c
index 2f6d806..e45353f 100644
--- a/ndctl/lib/libndctl.c
+++ b/ndctl/lib/libndctl.c
@@ -1646,41 +1646,9 @@ static int ndctl_bind(struct ndctl_ctx *ctx, struct kmod_module *module,
 static int ndctl_unbind(struct ndctl_ctx *ctx, const char *devpath);
 static struct kmod_module *to_module(struct ndctl_ctx *ctx, const char *alias);
 
-static int add_papr_dimm(struct ndctl_dimm *dimm, const char *dimm_base)
-{
-	int rc = -ENODEV;
-	char buf[SYSFS_ATTR_SIZE];
-	struct ndctl_ctx *ctx = dimm->bus->ctx;
-	char *path = calloc(1, strlen(dimm_base) + 100);
-	const char * const devname = ndctl_dimm_get_devname(dimm);
-
-	dbg(ctx, "%s: Probing of_pmem dimm at %s\n", devname, dimm_base);
-
-	if (!path)
-		return -ENOMEM;
-
-	/* construct path to the papr compatible dimm flags file */
-	sprintf(path, "%s/papr/flags", dimm_base);
-
-	if (ndctl_bus_is_papr_scm(dimm->bus) &&
-	    sysfs_read_attr(ctx, path, buf) == 0) {
-
-		dbg(ctx, "%s: Adding papr-scm dimm flags:\"%s\"\n", devname, buf);
-		dimm->cmd_family = NVDIMM_FAMILY_PAPR;
-
-		/* Parse dimm flags */
-		parse_papr_flags(dimm, buf);
-
-		/* Allocate monitor mode fd */
-		dimm->health_eventfd = open(path, O_RDONLY|O_CLOEXEC);
-		rc = 0;
-	}
-
-	free(path);
-	return rc;
-}
-
-static int add_nfit_dimm(struct ndctl_dimm *dimm, const char *dimm_base)
+static int populate_dimm_attributes(struct ndctl_dimm *dimm,
+				    const char *dimm_base,
+				    const char *bus_prefix)
 {
 	int i, rc = -1;
 	char buf[SYSFS_ATTR_SIZE];
@@ -1694,7 +1662,7 @@ static int add_nfit_dimm(struct ndctl_dimm *dimm, const char *dimm_base)
 	 * 'unique_id' may not be available on older kernels, so don't
 	 * fail if the read fails.
 	 */
-	sprintf(path, "%s/nfit/id", dimm_base);
+	sprintf(path, "%s/%s/id", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0) {
 		unsigned int b[9];
 
@@ -1709,68 +1677,74 @@ static int add_nfit_dimm(struct ndctl_dimm *dimm, const char *dimm_base)
 		}
 	}
 
-	sprintf(path, "%s/nfit/handle", dimm_base);
+	sprintf(path, "%s/%s/handle", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) < 0)
 		goto err_read;
 	dimm->handle = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/phys_id", dimm_base);
+	sprintf(path, "%s/%s/phys_id", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) < 0)
 		goto err_read;
 	dimm->phys_id = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/serial", dimm_base);
+	sprintf(path, "%s/%s/serial", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->serial = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/vendor", dimm_base);
+	sprintf(path, "%s/%s/vendor", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->vendor_id = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/device", dimm_base);
+	sprintf(path, "%s/%s/device", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->device_id = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/rev_id", dimm_base);
+	sprintf(path, "%s/%s/rev_id", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->revision_id = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/dirty_shutdown", dimm_base);
+	sprintf(path, "%s/%s/dirty_shutdown", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->dirty_shutdown = strtoll(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/subsystem_vendor", dimm_base);
+	sprintf(path, "%s/%s/subsystem_vendor", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->subsystem_vendor_id = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/subsystem_device", dimm_base);
+	sprintf(path, "%s/%s/subsystem_device", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->subsystem_device_id = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/subsystem_rev_id", dimm_base);
+	sprintf(path, "%s/%s/subsystem_rev_id", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->subsystem_revision_id = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/family", dimm_base);
+	sprintf(path, "%s/%s/family", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->cmd_family = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/dsm_mask", dimm_base);
+	sprintf(path, "%s/%s/dsm_mask", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->nfit_dsm_mask = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/format", dimm_base);
+	sprintf(path, "%s/%s/format", dimm_base, bus_prefix);
 	if (sysfs_read_attr(ctx, path, buf) == 0)
 		dimm->format[0] = strtoul(buf, NULL, 0);
 	for (i = 1; i < dimm->formats; i++) {
-		sprintf(path, "%s/nfit/format%d", dimm_base, i);
+		sprintf(path, "%s/%s/format%d", dimm_base, bus_prefix, i);
 		if (sysfs_read_attr(ctx, path, buf) == 0)
 			dimm->format[i] = strtoul(buf, NULL, 0);
 	}
 
-	sprintf(path, "%s/nfit/flags", dimm_base);
-	if (sysfs_read_attr(ctx, path, buf) == 0)
-		parse_nfit_mem_flags(dimm, buf);
+	sprintf(path, "%s/%s/flags", dimm_base, bus_prefix);
+	if (sysfs_read_attr(ctx, path, buf) == 0) {
+		if (ndctl_bus_has_nfit(dimm->bus))
+			parse_nfit_mem_flags(dimm, buf);
+		else if (ndctl_bus_is_papr_scm(dimm->bus)) {
+			dimm->cmd_family = NVDIMM_FAMILY_PAPR;
+			parse_papr_flags(dimm, buf);
+		}
+	}
 
 	dimm->health_eventfd = open(path, O_RDONLY|O_CLOEXEC);
 	rc = 0;
@@ -1792,7 +1766,8 @@ static void *add_dimm(void *parent, int id, const char *dimm_base)
 	if (!path)
 		return NULL;
 
-	sprintf(path, "%s/nfit/formats", dimm_base);
+	sprintf(path, "%s/%s/formats", dimm_base,
+		ndctl_bus_has_nfit(bus) ? "nfit" : "papr");
 	if (sysfs_read_attr(ctx, path, buf) < 0)
 		formats = 1;
 	else
@@ -1866,13 +1841,12 @@ static void *add_dimm(void *parent, int id, const char *dimm_base)
 	else
 		dimm->fwa_result = fwa_result_to_result(buf);
 
+	dimm->formats = formats;
 	/* Check if the given dimm supports nfit */
 	if (ndctl_bus_has_nfit(bus)) {
-		dimm->formats = formats;
-		rc = add_nfit_dimm(dimm, dimm_base);
-	} else if (ndctl_bus_has_of_node(bus)) {
-		rc = add_papr_dimm(dimm, dimm_base);
-	}
+		rc = populate_dimm_attributes(dimm, dimm_base, "nfit");
+	} else if (ndctl_bus_has_of_node(bus))
+		rc = populate_dimm_attributes(dimm, dimm_base, "papr");
 
 	if (rc == -ENODEV) {
 		/* Unprobed dimm with no family */
@@ -2531,13 +2505,12 @@ static void *add_region(void *parent, int id, const char *region_base)
 		goto err_read;
 	region->num_mappings = strtoul(buf, NULL, 0);
 
-	sprintf(path, "%s/nfit/range_index", region_base);
-	if (ndctl_bus_has_nfit(bus)) {
-		if (sysfs_read_attr(ctx, path, buf) < 0)
-			goto err_read;
-		region->range_index = strtoul(buf, NULL, 0);
-	} else
+	sprintf(path, "%s/%s/range_index", region_base,
+		ndctl_bus_has_nfit(bus) ? "nfit": "papr");
+	if (sysfs_read_attr(ctx, path, buf) < 0)
 		region->range_index = -1;
+	else
+		region->range_index = strtoul(buf, NULL, 0);
 
 	sprintf(path, "%s/read_only", region_base);
 	if (sysfs_read_attr(ctx, path, buf) < 0)