Re: [PATCH v2] mm: generalize ZONE_[DMA|DMA32]

ZONE_[DMA|DMA32] configs have duplicate definitions on platforms
that subscribe them. Instead, just make them generic options which
can be selected on applicable platforms.

Also only x86/arm64 architectures could enable both ZONE_DMA and
ZONE_DMA32 if EXPERT, add ARCH_HAS_ZONE_DMA_SET to make dma zone
configurable and visible on the two architectures.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Richard Henderson <redacted>
Cc: Russell King <linux@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> # for arm64
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # for m68k
Acked-by: Mike Rapoport <redacted>
Signed-off-by: Kefeng Wang <redacted>
---
v2:
-i386 can't enable ZONE_DMA32, fix it.
-make ZONE_DMA default y on X86 as before.
-collect ACKs

 arch/alpha/Kconfig                     |  5 +----
 arch/arm/Kconfig                       |  3 ---
 arch/arm64/Kconfig                     |  9 +--------
 arch/ia64/Kconfig                      |  4 +---
 arch/m68k/Kconfig                      |  5 +----
 arch/microblaze/Kconfig                |  4 +---
 arch/mips/Kconfig                      |  7 -------
 arch/powerpc/Kconfig                   |  4 ----
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 arch/riscv/Kconfig                     |  5 +----
 arch/s390/Kconfig                      |  4 +---
 arch/sparc/Kconfig                     |  5 +----
 arch/x86/Kconfig                       | 15 ++-------------
 mm/Kconfig                             | 12 ++++++++++++
 14 files changed, 23 insertions(+), 60 deletions(-)

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 5998106faa60..6a69a14c4825 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig

@@ -40,6 +40,7 @@ config ALPHA
 	select MMU_GATHER_NO_RANGE
 	select SET_FS
 	select SPARSEMEM_EXTREME if SPARSEMEM
+	select ZONE_DMA
 	help
 	  The Alpha is a 64-bit general-purpose processor designed and
 	  marketed by the Digital Equipment Corporation of blessed memory,

@@ -65,10 +66,6 @@ config GENERIC_CALIBRATE_DELAY
 	bool
 	default y
 
-config ZONE_DMA
-	bool
-	default y
-
 config GENERIC_ISA_DMA
 	bool
 	default y

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 24804f11302d..000c3f80b58e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig

@@ -218,9 +218,6 @@ config GENERIC_CALIBRATE_DELAY
 config ARCH_MAY_HAVE_PC_FDC
 	bool
 
-config ZONE_DMA
-	bool
-
 config ARCH_SUPPORTS_UPROBES
 	def_bool y
 

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 9f1d8566bbf9..42794474f37f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig

@@ -42,6 +42,7 @@ config ARM64
 	select ARCH_HAS_SYSCALL_WRAPPER
 	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
+	select ARCH_HAS_ZONE_DMA_SET if EXPERT
 	select ARCH_HAVE_ELF_PROT
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_INLINE_READ_LOCK if !PREEMPTION

@@ -307,14 +308,6 @@ config GENERIC_CSUM
 config GENERIC_CALIBRATE_DELAY
 	def_bool y
 
-config ZONE_DMA
-	bool "Support DMA zone" if EXPERT
-	default y
-
-config ZONE_DMA32
-	bool "Support DMA32 zone" if EXPERT
-	default y
-
 config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
 	def_bool y
 

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 279252e3e0f7..fd8503a0088a 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig

@@ -60,6 +60,7 @@ config IA64
 	select NUMA if !FLATMEM
 	select PCI_MSI_ARCH_FALLBACKS if PCI_MSI
 	select SET_FS
+	select ZONE_DMA32
 	default y
 	help
 	  The Itanium Processor Family is Intel's 64-bit successor to

@@ -72,9 +73,6 @@ config 64BIT
 	select ATA_NONSTANDARD if ATA
 	default y
 
-config ZONE_DMA32
-	def_bool y
-
 config MMU
 	bool
 	default y

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 372e4e69c43a..05a729c6ad7f 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig

@@ -34,6 +34,7 @@ config M68K
 	select SET_FS
 	select UACCESS_MEMCPY if !MMU
 	select VIRT_TO_BUS
+	select ZONE_DMA
 
 config CPU_BIG_ENDIAN
 	def_bool y

@@ -62,10 +63,6 @@ config TIME_LOW_RES
 config NO_IOPORT_MAP
 	def_bool y
 
-config ZONE_DMA
-	bool
-	default y
-
 config HZ
 	int
 	default 1000 if CLEOPATRA

diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 0660f47012bc..14a67a42fcae 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig

@@ -43,6 +43,7 @@ config MICROBLAZE
 	select MMU_GATHER_NO_RANGE
 	select SPARSE_IRQ
 	select SET_FS
+	select ZONE_DMA
 
 # Endianness selection
 choice

@@ -60,9 +61,6 @@ config CPU_LITTLE_ENDIAN
 
 endchoice
 
-config ZONE_DMA
-	def_bool y
-
 config ARCH_HAS_ILOG2_U32
 	def_bool n