powerpc/pseries/memhp: Log more error conditions in add path

When an add operation for multiple LMBs fails, there is currently
little indication from the kernel of what went wrong. Be a little more
verbose about error conditions in the add paths.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231114-pseries-memhp-fixes-v1-3-fb8f2bb7c557@linux.ibm.com

arch/powerpc/platforms/pseries/hotplug-memory.c

@@ -208,8 +208,10 @@ static int dlpar_change_lmb_state(struct drmem_lmb *lmb, bool online)
 	int rc;
 
 	mem_block = lmb_to_memblock(lmb);
-	if (!mem_block)
+	if (!mem_block) {
+		pr_err("Failed memory block lookup for LMB 0x%x\n", lmb->drc_index);
 		return -EINVAL;
+	}
 
 	if (online && mem_block->dev.offline)
 		rc = device_online(&mem_block->dev);
@@ -576,6 +578,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
 	rc = update_lmb_associativity_index(lmb);
 	if (rc) {
 		dlpar_release_drc(lmb->drc_index);
+		pr_err("Failed to configure LMB 0x%x\n", lmb->drc_index);
 		return rc;
 	}
 
@@ -589,12 +592,14 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
 	/* Add the memory */
 	rc = __add_memory(nid, lmb->base_addr, block_sz, MHP_MEMMAP_ON_MEMORY);
 	if (rc) {
+		pr_err("Failed to add LMB 0x%x to node %u", lmb->drc_index, nid);
 		invalidate_lmb_associativity_index(lmb);
 		return rc;
 	}
 
 	rc = dlpar_online_lmb(lmb);
 	if (rc) {
+		pr_err("Failed to online LMB 0x%x on node %u\n", lmb->drc_index, nid);
 		__remove_memory(lmb->base_addr, block_sz);
 		invalidate_lmb_associativity_index(lmb);
 	} else {