Merge patch series "treewide: remove unnecessary invalid range checks in memblock iteration loops"

Sang-Heon Jeon <ekffu200098@gmail.com> says:

treewide: remove unnecessary invalid range checks in memblock iteration loops

The memblock API guarantees that for_each_mem_range() and
for_each_mem_pfn_range() never return an invalid range, meaning start is
always less than end.

Several memblock callers still have unnecessary invalid range checks in
their loop bodies, so remove them.

Patches 1-6 cover for_each_mem_range() callers. memblock never stores a
zero-size region, so the range it returns always has start < end. Some
callers apply __va() or __phys_to_virt() before comparing, but these keep
start < end too, so the check is unreachable.

Patches 7-8 cover for_each_mem_pfn_range() callers. __next_mem_pfn_range()
skips any region that does not contain a whole page, so it only ever returns
start_pfn < end_pfn and the check is unnecessary.

For reference, commit 36ca7f4be8 ("arm64: mm: Remove bogus stop
condition from map_mem() loop") did a similar cleanup in arm64 map_mem().

* patches from https://patch.msgid.link/20260630150413.1718632-1-ekffu200098@gmail.com
  arm64: mm: remove unreachable invalid range check in kasan_init_shadow()
  LoongArch: remove unreachable invalid range check in kasan_init()
  riscv: remove unreachable invalid range check in
    create_linear_mapping_page_table()
  riscv: remove unreachable invalid range check in kasan_init()
  ARM: remove unreachable invalid range check in kasan_init()
  powerpc64/kasan: Remove unreachable invalid range check in
    kasan_init_phys_region()
  mm: remove unnecessary empty range check in early_calculate_totalpages()
  mm/hugetlb: remove unnecessary empty range check in
    hugetlb_bootmem_set_nodes()

Link: https://patch.msgid.link/20260630150413.1718632-1-ekffu200098@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

arch/arm/mm/kasan_init.c

@@ -262,12 +262,6 @@ void __init kasan_init(void)
 				&pa_start, &pa_end, &arm_lowmem_limit);
 			end = __va(arm_lowmem_limit);
 		}
-		if (start >= end) {
-			pr_info("Skipping invalid memory block %pa-%pa (virtual %p-%p)\n",
-				&pa_start, &pa_end, start, end);
-			continue;
-		}
-
 		create_mapping(start, end);
 	}
 

arch/arm64/mm/kasan_init.c

@@ -353,9 +353,6 @@ static void __init kasan_init_shadow(void)
 		void *start = (void *)__phys_to_virt(pa_start);
 		void *end = (void *)__phys_to_virt(pa_end);
 
-		if (start >= end)
-			break;
-
 		kasan_map_populate((unsigned long)kasan_mem_to_shadow(start),
 				   (unsigned long)kasan_mem_to_shadow(end),
 				   early_pfn_to_nid(virt_to_pfn(start)));

arch/loongarch/mm/kasan_init.c

@@ -305,9 +305,6 @@ void __init kasan_init(void)
 		void *start = (void *)phys_to_virt(pa_start);
 		void *end   = (void *)phys_to_virt(pa_end);
 
-		if (start >= end)
-			break;
-
 		kasan_map_populate((unsigned long)mem_to_shadow(start),
 			(unsigned long)mem_to_shadow(end), NUMA_NO_NODE);
 	}

arch/powerpc/mm/kasan/init_book3e_64.c

@@ -68,9 +68,6 @@ static void __init kasan_init_phys_region(void *start, void *end)
 	unsigned long k_start, k_end, k_cur;
 	void *va;
 
-	if (start >= end)
-		return;
-
 	k_start = ALIGN_DOWN((unsigned long)kasan_mem_to_shadow(start), PAGE_SIZE);
 	k_end = ALIGN((unsigned long)kasan_mem_to_shadow(end), PAGE_SIZE);
 

arch/powerpc/mm/kasan/init_book3s_64.c

@@ -24,9 +24,6 @@ static void __init kasan_init_phys_region(void *start, void *end)
 	unsigned long k_start, k_end, k_cur;
 	void *va;
 
-	if (start >= end)
-		return;
-
 	k_start = ALIGN_DOWN((unsigned long)kasan_mem_to_shadow(start), PAGE_SIZE);
 	k_end = ALIGN((unsigned long)kasan_mem_to_shadow(end), PAGE_SIZE);
 

arch/riscv/mm/init.c

@@ -1229,8 +1229,6 @@ static void __init create_linear_mapping_page_table(void)
 
 	/* Map all memory banks in the linear mapping */
 	for_each_mem_range(i, &start, &end) {
-		if (start >= end)
-			break;
 		if (start <= __pa(PAGE_OFFSET) &&
 		    __pa(PAGE_OFFSET) < end)
 			start = __pa(PAGE_OFFSET);

arch/riscv/mm/kasan_init.c

@@ -512,9 +512,6 @@ void __init kasan_init(void)
 		void *start = (void *)__va(p_start);
 		void *end = (void *)__va(p_end);
 
-		if (start >= end)
-			break;
-
 		kasan_populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end));
 	}
 

mm/hugetlb.c

@@ -4444,15 +4444,12 @@ hugetlb_early_param("default_hugepagesz", default_hugepagesz_setup);
 void __init hugetlb_bootmem_set_nodes(void)
 {
 	int i, nid;
-	unsigned long start_pfn, end_pfn;
 
 	if (!nodes_empty(hugetlb_bootmem_nodes))
 		return;
 
-	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
-		if (end_pfn > start_pfn)
-			node_set(nid, hugetlb_bootmem_nodes);
-	}
+	for_each_mem_pfn_range(i, MAX_NUMNODES, NULL, NULL, &nid)
+		node_set(nid, hugetlb_bootmem_nodes);
 }
 
 void __init hugetlb_bootmem_alloc(void)

mm/mm_init.c

@@ -332,8 +332,7 @@ static unsigned long __init early_calculate_totalpages(void)
 		unsigned long pages = end_pfn - start_pfn;
 
 		totalpages += pages;
-		if (pages)
-			node_set_state(nid, N_MEMORY);
+		node_set_state(nid, N_MEMORY);
 	}
 	return totalpages;
 }