Merge tag 'fixes-2025-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock fixes from Mike Rapoport:

 - printk cleanups in memblock and numa_memblks

 - update kernel-doc for MEMBLOCK_RSRV_NOINIT to be more accurate and
   detailed

* tag 'fixes-2025-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  memblock: fix kernel-doc for MEMBLOCK_RSRV_NOINIT
  mm: numa,memblock: Use SZ_1M macro to denote bytes to MB conversion
  mm/numa_memblks: Use pr_debug instead of printk(KERN_DEBUG)

4 files changed, 21 insertions, 13 deletions

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index b96746376e17..fcda8481de9a 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -40,8 +40,9 @@ extern unsigned long long max_possible_pfn;
  * via a driver, and never indicated in the firmware-provided memory map as
  * system RAM. This corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED in the
  * kernel resource tree.
- * @MEMBLOCK_RSRV_NOINIT: memory region for which struct pages are
- * not initialized (only for reserved regions).
+ * @MEMBLOCK_RSRV_NOINIT: reserved memory region for which struct pages are not
+ * fully initialized. Users of this flag are responsible to properly initialize
+ * struct pages of this region
  * @MEMBLOCK_RSRV_KERN: memory region that is reserved for kernel use,
  * either explictitly with memblock_reserve_kern() or via memblock
  * allocation APIs. All memblock allocations set this flag.
diff --git a/mm/memblock.c b/mm/memblock.c
index 154f1d73b61f..117d963e677c 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -780,9 +780,9 @@ bool __init_memblock memblock_validate_numa_coverage(unsigned long threshold_byt
 	}
 
 	if ((nr_pages << PAGE_SHIFT) > threshold_bytes) {
-		mem_size_mb = memblock_phys_mem_size() >> 20;
+		mem_size_mb = memblock_phys_mem_size() / SZ_1M;
 		pr_err("NUMA: no nodes coverage for %luMB of %luMB RAM\n",
-		       (nr_pages << PAGE_SHIFT) >> 20, mem_size_mb);
+		       (nr_pages << PAGE_SHIFT) / SZ_1M, mem_size_mb);
 		return false;
 	}
 
@@ -1091,13 +1091,20 @@ int __init_memblock memblock_clear_nomap(phys_addr_t base, phys_addr_t size)
 
 /**
  * memblock_reserved_mark_noinit - Mark a reserved memory region with flag
- * MEMBLOCK_RSRV_NOINIT which results in the struct pages not being initialized
- * for this region.
+ * MEMBLOCK_RSRV_NOINIT
+ *
  * @base: the base phys addr of the region
  * @size: the size of the region
  *
- * struct pages will not be initialized for reserved memory regions marked with
- * %MEMBLOCK_RSRV_NOINIT.
+ * The struct pages for the reserved regions marked %MEMBLOCK_RSRV_NOINIT will
+ * not be fully initialized to allow the caller optimize their initialization.
+ *
+ * When %CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, setting this flag
+ * completely bypasses the initialization of struct pages for such region.
+ *
+ * When %CONFIG_DEFERRED_STRUCT_PAGE_INIT is disabled, struct pages in this
+ * region will be initialized with default values but won't be marked as
+ * reserved.
  *
  * Return: 0 on success, -errno on failure.
  */
diff --git a/mm/numa_emulation.c b/mm/numa_emulation.c
index 9d55679d99ce..703c8fa05048 100644
--- a/mm/numa_emulation.c
+++ b/mm/numa_emulation.c
@@ -73,7 +73,7 @@ static int __init emu_setup_memblk(struct numa_meminfo *ei,
 	}
 
 	printk(KERN_INFO "Faking node %d at [mem %#018Lx-%#018Lx] (%LuMB)\n",
-	       nid, eb->start, eb->end - 1, (eb->end - eb->start) >> 20);
+	       nid, eb->start, eb->end - 1, (eb->end - eb->start) / SZ_1M);
 	return 0;
 }
 
@@ -264,7 +264,7 @@ static int __init split_nodes_size_interleave_uniform(struct numa_meminfo *ei,
 	min_size = ALIGN(max(min_size, FAKE_NODE_MIN_SIZE), FAKE_NODE_MIN_SIZE);
 	if (size < min_size) {
 		pr_err("Fake node size %LuMB too small, increasing to %LuMB\n",
-			size >> 20, min_size >> 20);
+			size / SZ_1M, min_size / SZ_1M);
 		size = min_size;
 	}
 	size = ALIGN_DOWN(size, FAKE_NODE_MIN_SIZE);
diff --git a/mm/numa_memblks.c b/mm/numa_memblks.c
index 541a99c4071a..5b009a9cd8b4 100644
--- a/mm/numa_memblks.c
+++ b/mm/numa_memblks.c
@@ -76,7 +76,7 @@ static int __init numa_alloc_distance(void)
 		for (j = 0; j < cnt; j++)
 			numa_distance[i * cnt + j] = i == j ?
 				LOCAL_DISTANCE : REMOTE_DISTANCE;
-	printk(KERN_DEBUG "NUMA: Initialized distance table, cnt=%d\n", cnt);
+	pr_debug("NUMA: Initialized distance table, cnt=%d\n", cnt);
 
 	return 0;
 }
@@ -427,9 +427,9 @@ static int __init numa_register_meminfo(struct numa_meminfo *mi)
 		unsigned long pfn_align = node_map_pfn_alignment();
 
 		if (pfn_align && pfn_align < PAGES_PER_SECTION) {
-			unsigned long node_align_mb = PFN_PHYS(pfn_align) >> 20;
+			unsigned long node_align_mb = PFN_PHYS(pfn_align) / SZ_1M;
 
-			unsigned long sect_align_mb = PFN_PHYS(PAGES_PER_SECTION) >> 20;
+			unsigned long sect_align_mb = PFN_PHYS(PAGES_PER_SECTION) / SZ_1M;
 
 			pr_warn("Node alignment %luMB < min %luMB, rejecting NUMA config\n",
 				node_align_mb, sect_align_mb);