16 files changed, 19 insertions, 23 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a11dfcc2a130..5fd344bd06b9 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -4,7 +4,6 @@ config ARM
         default y
         select ARCH_32BIT_OFF_T
         select ARCH_CLOCKSOURCE_DATA
-        select ARCH_DISCARD_MEMBLOCK if !HAVE_ARCH_PFN_VALID && !KEXEC
         select ARCH_HAS_DEBUG_VIRTUAL if MMU
         select ARCH_HAS_DEVMEM_IS_ALLOWED
         select ARCH_HAS_ELF_RANDOMIZE
@@ -22,6 +21,7 @@ config ARM
         select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
         select ARCH_HAVE_CUSTOM_GPIO_H
         select ARCH_HAS_GCOV_PROFILE_ALL
+        select ARCH_KEEP_MEMBLOCK if HAVE_ARCH_PFN_VALID || KEXEC
         select ARCH_MIGHT_HAVE_PC_PARPORT
         select ARCH_NO_SG_CHAIN if !ARM_HAS_SG_CHAIN
         select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7a1aa53d188d..69a59a5d1143 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -60,6 +60,7 @@ config ARM64
         select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPT
         select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPT
         select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPT
+        select ARCH_KEEP_MEMBLOCK
         select ARCH_USE_CMPXCHG_LOCKREF
         select ARCH_USE_QUEUED_RWLOCKS
         select ARCH_USE_QUEUED_SPINLOCKS
diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index 3e54a53208d5..b7d404bbaa0f 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -22,7 +22,6 @@ config HEXAGON
         select GENERIC_IRQ_SHOW
         select HAVE_ARCH_KGDB
         select HAVE_ARCH_TRACEHOOK
-        select ARCH_DISCARD_MEMBLOCK
         select NEED_SG_DMA_LENGTH
         select NO_IOPORT_MAP
         select GENERIC_IOMAP
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 73a26f04644e..7468d8e50467 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -33,7 +33,6 @@ config IA64
         select ARCH_HAS_DMA_COHERENT_TO_PFN if SWIOTLB
         select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB
         select VIRT_TO_BUS
-        select ARCH_DISCARD_MEMBLOCK
         select GENERIC_IRQ_PROBE
         select GENERIC_PENDING_IRQ if SMP
         select GENERIC_IRQ_SHOW
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index fe5cc2da6d10..218e037ef901 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -26,7 +26,6 @@ config M68K
         select MODULES_USE_ELF_RELA
         select OLD_SIGSUSPEND3
         select OLD_SIGACTION
-        select ARCH_DISCARD_MEMBLOCK
         select MMU_GATHER_NO_RANGE if MMU
 
 config CPU_BIG_ENDIAN
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index ff8cff9fcf54..677e5bfeff47 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -5,7 +5,6 @@ config MIPS
         select ARCH_32BIT_OFF_T if !64BIT
         select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT
         select ARCH_CLOCKSOURCE_DATA
-        select ARCH_DISCARD_MEMBLOCK
         select ARCH_HAS_ELF_RANDOMIZE
         select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
         select ARCH_HAS_UBSAN_SANITIZE_ALL
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index ea37394ff3ea..26a9c760a98b 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -23,7 +23,6 @@ config NIOS2
         select SPARSE_IRQ
         select USB_ARCH_HAS_HCD if USB_SUPPORT
         select CPU_NO_EFFICIENT_FFS
-        select ARCH_DISCARD_MEMBLOCK
         select MMU_GATHER_NO_RANGE if MMU
 
 config GENERIC_CSUM
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index d7996cfaceca..8c1c636308c8 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -137,6 +137,7 @@ config PPC
         select ARCH_HAS_UBSAN_SANITIZE_ALL
         select ARCH_HAS_ZONE_DEVICE             if PPC_BOOK3S_64
         select ARCH_HAVE_NMI_SAFE_CMPXCHG
+        select ARCH_KEEP_MEMBLOCK
         select ARCH_MIGHT_HAVE_PC_PARPORT
         select ARCH_MIGHT_HAVE_PC_SERIO
         select ARCH_OPTIONAL_KERNEL_RWX         if ARCH_HAS_STRICT_KERNEL_RWX
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index d0c046af65fa..109243fdb6ec 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -100,6 +100,7 @@ config S390
         select ARCH_INLINE_WRITE_UNLOCK_BH
         select ARCH_INLINE_WRITE_UNLOCK_IRQ
         select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
+        select ARCH_KEEP_MEMBLOCK
         select ARCH_SAVE_PAGE_KEYS if HIBERNATION
         select ARCH_SUPPORTS_ATOMIC_RMW
         select ARCH_SUPPORTS_NUMA_BALANCING
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 2a77033e1e7c..b77f512bb176 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -10,7 +10,6 @@ config SUPERH
         select DMA_DECLARE_COHERENT
         select HAVE_IDE if HAS_IOPORT_MAP
         select HAVE_MEMBLOCK_NODE_MAP
-        select ARCH_DISCARD_MEMBLOCK
         select HAVE_OPROFILE
         select HAVE_ARCH_TRACEHOOK
         select HAVE_PERF_EVENTS
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f21bc56e5d7b..818b361094ed 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -47,7 +47,6 @@ config X86
         select ARCH_32BIT_OFF_T                 if X86_32
         select ARCH_CLOCKSOURCE_DATA
         select ARCH_CLOCKSOURCE_INIT
-        select ARCH_DISCARD_MEMBLOCK
         select ARCH_HAS_ACPI_TABLE_UPGRADE      if ACPI
         select ARCH_HAS_DEBUG_VIRTUAL
         select ARCH_HAS_DEVMEM_IS_ALLOWED
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 47e3c0612592..676d3900e1bd 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -96,13 +96,14 @@ struct memblock {
 extern struct memblock memblock;
 extern int memblock_debug;
 
-#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
+#ifndef CONFIG_ARCH_KEEP_MEMBLOCK
 #define __init_memblock __meminit
 #define __initdata_memblock __meminitdata
 void memblock_discard(void);
 #else
 #define __init_memblock
 #define __initdata_memblock
+static inline void memblock_discard(void) {}
 #endif
 
 #define memblock_dbg(fmt, ...) \
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index f7fb8f6a688f..072b6ee55e3f 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -500,13 +500,7 @@ static int locate_mem_hole_callback(struct resource *res, void *arg)
         return locate_mem_hole_bottom_up(start, end, kbuf);
 }
 
-#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
-static int kexec_walk_memblock(struct kexec_buf *kbuf,
-                               int (*func)(struct resource *, void *))
-{
-        return 0;
-}
-#else
+#ifdef CONFIG_ARCH_KEEP_MEMBLOCK
 static int kexec_walk_memblock(struct kexec_buf *kbuf,
                                int (*func)(struct resource *, void *))
 {
@@ -550,6 +544,12 @@ static int kexec_walk_memblock(struct kexec_buf *kbuf,
 
         return ret;
 }
+#else
+static int kexec_walk_memblock(struct kexec_buf *kbuf,
+                               int (*func)(struct resource *, void *))
+{
+        return 0;
+}
 #endif
 
 /**
@@ -589,7 +589,7 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
         if (kbuf->mem != KEXEC_BUF_MEM_UNKNOWN)
                 return 0;
 
-        if (IS_ENABLED(CONFIG_ARCH_DISCARD_MEMBLOCK))
+        if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
                 ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
         else
                 ret = kexec_walk_memblock(kbuf, locate_mem_hole_callback);
diff --git a/mm/Kconfig b/mm/Kconfig
index 71e697e693df..c5124c2cb0b2 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -136,7 +136,7 @@ config HAVE_MEMBLOCK_PHYS_MAP
 config HAVE_GENERIC_GUP
         bool
 
-config ARCH_DISCARD_MEMBLOCK
+config ARCH_KEEP_MEMBLOCK
         bool
 
 config MEMORY_ISOLATION
diff --git a/mm/memblock.c b/mm/memblock.c
index f315eca9f4a1..6bbad46f4d2c 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -94,7 +94,7 @@
  * :c:func:`mem_init` function frees all the memory to the buddy page
  * allocator.
  *
- * If an architecure enables %CONFIG_ARCH_DISCARD_MEMBLOCK, the
+ * Unless an architecure enables %CONFIG_ARCH_KEEP_MEMBLOCK, the
  * memblock data structures will be discarded after the system
  * initialization compltes.
  */
@@ -375,7 +375,7 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u
         }
 }
 
-#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
+#ifndef CONFIG_ARCH_KEEP_MEMBLOCK
 /**
  * memblock_discard - discard memory and reserved arrays if they were allocated
  */
@@ -1987,7 +1987,7 @@ unsigned long __init memblock_free_all(void)
         return pages;
 }
 
-#if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK)
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_ARCH_KEEP_MEMBLOCK)
 
 static int memblock_debug_show(struct seq_file *m, void *private)
 {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index cbda9aea0bf5..f2f3fb4921d1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1896,10 +1896,9 @@ void __init page_alloc_init_late(void)
         /* Reinit limits that are based on free pages after the kernel is up */
         files_maxfiles_init();
 #endif
-#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK
+
         /* Discard memblock private memory */
         memblock_discard();
-#endif
 
         for_each_populated_zone(zone)
                 set_zone_contiguous(zone);