Revert "mm: CONFIG_NR_ZONES_EXTENDED"

BugLink: http://bugs.launchpad.net/bugs/1563293

This reverts commit f671c3e6.

This patch never made it upstream. Instead, commit
b11a7b94 ('mm: exclude ZONE_DEVICE from GFP_ZONE_TABLE')
replaced it.
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

arch/x86/Kconfig

@@ -1375,10 +1375,8 @@ config NUMA_EMU
 
 config NODES_SHIFT
 	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
-	range 1 10 if !NR_ZONES_EXTENDED
-	range 1 9 if NR_ZONES_EXTENDED
-	default "10" if MAXSMP && !NR_ZONES_EXTENDED
-	default "9" if MAXSMP && NR_ZONES_EXTENDED
+	range 1 10
+	default "10" if MAXSMP
 	default "6" if X86_64
 	default "3"
 	depends on NEED_MULTIPLE_NODES

debian.master/config/amd64/config.common.amd64

@@ -260,7 +260,6 @@ CONFIG_NFC=m
 CONFIG_NODES_SHIFT=6
 CONFIG_NOZOMI=m
 CONFIG_NR_CPUS=256
-CONFIG_NR_ZONES_EXTENDED=y
 CONFIG_NTB=m
 # CONFIG_NTFS_RW is not set
 CONFIG_NUMA=y

debian.master/config/armhf/config.common.armhf

@@ -253,7 +253,6 @@ CONFIG_NEW_LEDS=y
 CONFIG_NFC=m
 CONFIG_NOZOMI=m
 CONFIG_NR_CPUS=4
-# CONFIG_NR_ZONES_EXTENDED is not set
 CONFIG_NTB=m
 # CONFIG_NTFS_RW is not set
 CONFIG_NVMEM=m

debian.master/config/i386/config.common.i386

@@ -257,7 +257,6 @@ CONFIG_NEW_LEDS=y
 CONFIG_NFC=m
 CONFIG_NOZOMI=m
 CONFIG_NR_CPUS=8
-# CONFIG_NR_ZONES_EXTENDED is not set
 CONFIG_NTB=m
 # CONFIG_NTFS_RW is not set
 CONFIG_NVMEM=m

debian.master/config/powerpc/config.common.powerpc

@@ -250,7 +250,6 @@ CONFIG_NEW_LEDS=y
 CONFIG_NFC=m
 CONFIG_NODES_SHIFT=8
 CONFIG_NOZOMI=m
-# CONFIG_NR_ZONES_EXTENDED is not set
 CONFIG_NTB=m
 # CONFIG_NTFS_RW is not set
 CONFIG_NUMA_BALANCING_DEFAULT_ENABLED=y

include/linux/gfp.h

@@ -322,29 +322,22 @@ static inline bool gfpflags_allow_blocking(const gfp_t gfp_flags)
  *       0xe    => BAD (MOVABLE+DMA32+HIGHMEM)
  *       0xf    => BAD (MOVABLE+DMA32+HIGHMEM+DMA)
  *
- * GFP_ZONES_SHIFT must be <= 2 on 32 bit platforms.
+ * ZONES_SHIFT must be <= 2 on 32 bit platforms.
  */
 
-#if defined(CONFIG_ZONE_DEVICE) && (MAX_NR_ZONES-1) <= 4
-/* ZONE_DEVICE is not a valid GFP zone specifier */
-#define GFP_ZONES_SHIFT 2
-#else
-#define GFP_ZONES_SHIFT ZONES_SHIFT
-#endif
-
-#if 16 * GFP_ZONES_SHIFT > BITS_PER_LONG
-#error GFP_ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
+#if 16 * ZONES_SHIFT > BITS_PER_LONG
+#error ZONES_SHIFT too large to create GFP_ZONE_TABLE integer
 #endif
 
 #define GFP_ZONE_TABLE ( \
-	(ZONE_NORMAL << 0 * GFP_ZONES_SHIFT)					\
-	| (OPT_ZONE_DMA << ___GFP_DMA * GFP_ZONES_SHIFT)			\
-	| (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * GFP_ZONES_SHIFT)		\
-	| (OPT_ZONE_DMA32 << ___GFP_DMA32 * GFP_ZONES_SHIFT)		      	\
-	| (ZONE_NORMAL << ___GFP_MOVABLE * GFP_ZONES_SHIFT)			\
-	| (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * GFP_ZONES_SHIFT)	\
-	| (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * GFP_ZONES_SHIFT)	\
-	| (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * GFP_ZONES_SHIFT)	\
+	(ZONE_NORMAL << 0 * ZONES_SHIFT)				      \
+	| (OPT_ZONE_DMA << ___GFP_DMA * ZONES_SHIFT)			      \
+	| (OPT_ZONE_HIGHMEM << ___GFP_HIGHMEM * ZONES_SHIFT)		      \
+	| (OPT_ZONE_DMA32 << ___GFP_DMA32 * ZONES_SHIFT)		      \
+	| (ZONE_NORMAL << ___GFP_MOVABLE * ZONES_SHIFT)			      \
+	| (OPT_ZONE_DMA << (___GFP_MOVABLE | ___GFP_DMA) * ZONES_SHIFT)	      \
+	| (ZONE_MOVABLE << (___GFP_MOVABLE | ___GFP_HIGHMEM) * ZONES_SHIFT)   \
+	| (OPT_ZONE_DMA32 << (___GFP_MOVABLE | ___GFP_DMA32) * ZONES_SHIFT)   \
 )
 
 /*
@@ -369,8 +362,8 @@ static inline enum zone_type gfp_zone(gfp_t flags)
 	enum zone_type z;
 	int bit = (__force int) (flags & GFP_ZONEMASK);
 
-	z = (GFP_ZONE_TABLE >> (bit * GFP_ZONES_SHIFT)) &
-					 ((1 << GFP_ZONES_SHIFT) - 1);
+	z = (GFP_ZONE_TABLE >> (bit * ZONES_SHIFT)) &
+					 ((1 << ZONES_SHIFT) - 1);
 	VM_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
 	return z;
 }

include/linux/page-flags-layout.h

@@ -17,8 +17,6 @@
 #define ZONES_SHIFT 1
 #elif MAX_NR_ZONES <= 4
 #define ZONES_SHIFT 2
-#elif MAX_NR_ZONES <= 8
-#define ZONES_SHIFT 3
 #else
 #error ZONES_SHIFT -- too many zones configured adjust calculation
 #endif

mm/Kconfig

@@ -651,6 +651,8 @@ config IDLE_PAGE_TRACKING
 
 config ZONE_DEVICE
 	bool "Device memory (pmem, etc...) hotplug support" if EXPERT
+	default !ZONE_DMA
+	depends on !ZONE_DMA
 	depends on MEMORY_HOTPLUG
 	depends on MEMORY_HOTREMOVE
 	depends on X86_64 #arch_add_memory() comprehends device memory
@@ -664,10 +666,5 @@ config ZONE_DEVICE
 
 	  If FS_DAX is enabled, then say Y.
 
-config NR_ZONES_EXTENDED
-	bool
-	default n if !64BIT
-	default y if ZONE_DEVICE && ZONE_DMA && ZONE_DMA32
-
 config FRAME_VECTOR
 	bool