[PATCH 1/2] ARM: remove support for NOMMU ARMv4/v5

From: Arnd Bergmann
Date: Wed Mar 16 2022 - 17:13:31 EST

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From: Arnd Bergmann <arnd@xxxxxxxx>

It is possible to build MMU-less kernels for Cortex-M base
microcrontrollers as well as a couple of older platforms that
have not been converted to CONFIG_ARCH_MULTIPLATFORM,
specifically ep93xx, footbridge, dove, sa1100 and s3c24xx.

It seems unlikely that anybody has tested those configurations
in recent years, as even building them is frequently broken.
A patch I submitted caused another build time regression
in this configuration. I sent a patch for that, but it seems
better to also remove the option entirely, leaving ARMv7-M
as the only supported Arm NOMMU target for simplicity.

A couple of platforms have dependencies on CONFIG_MMU, those
can all be removed now. Notably, mach-integrator tries to
support MMU-less CPU cores, but those have not actually been
selectable for a long time.

This addresses several build failures in randconfig builds that
have accumulated over the years.

Cc: Vladimir Murzin <vladimir.murzin@xxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
If there are no objections, I'd apply this patch to the soc
tree for 5.18 as a cleanup.
---
arch/arm/Kconfig | 34 +++++++----------
arch/arm/mach-bcm/Kconfig | 1 -
.../mach-footbridge/include/mach/hardware.h | 20 ++++------
arch/arm/mach-footbridge/include/mach/io.h | 20 ----------
arch/arm/mach-integrator/Kconfig | 37 +------------------
arch/arm/mach-integrator/hardware.h | 5 ---
arch/arm/mach-nspire/Kconfig | 1 -
arch/arm/mach-orion5x/Kconfig | 2 +-
arch/arm/mach-shmobile/Kconfig | 2 +-
arch/arm/mach-ux500/Kconfig | 2 +-
10 files changed, 24 insertions(+), 100 deletions(-)
delete mode 100644 arch/arm/mach-footbridge/include/mach/io.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 5f0b40bab4fb..d184377ce2ae 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -304,6 +304,17 @@ config MMU
Select if you want MMU-based virtualised addressing space
support by paged memory management. If unsure, say 'Y'.

+config ARM_SINGLE_ARMV7M
+ def_bool !MMU
+ select ARM_NVIC
+ select AUTO_ZRELADDR
+ select TIMER_OF
+ select COMMON_CLK
+ select CPU_V7M
+ select NO_IOPORT_MAP
+ select SPARSE_IRQ
+ select USE_OF
+
config ARCH_MMAP_RND_BITS_MIN
default 8

@@ -318,12 +329,11 @@ config ARCH_MMAP_RND_BITS_MAX
#
choice
prompt "ARM system type"
- default ARM_SINGLE_ARMV7M if !MMU
- default ARCH_MULTIPLATFORM if MMU
+ depends on MMU
+ default ARCH_MULTIPLATFORM

config ARCH_MULTIPLATFORM
bool "Allow multiple platforms to be selected"
- depends on MMU
select ARCH_FLATMEM_ENABLE
select ARCH_SPARSEMEM_ENABLE
select ARCH_SELECT_MEMORY_MODEL
@@ -337,18 +347,6 @@ config ARCH_MULTIPLATFORM
select SPARSE_IRQ
select USE_OF

-config ARM_SINGLE_ARMV7M
- bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
- depends on !MMU
- select ARM_NVIC
- select AUTO_ZRELADDR
- select TIMER_OF
- select COMMON_CLK
- select CPU_V7M
- select NO_IOPORT_MAP
- select SPARSE_IRQ
- select USE_OF
-
config ARCH_EP93XX
bool "EP93xx-based"
select ARCH_SPARSEMEM_ENABLE
@@ -367,7 +365,6 @@ config ARCH_FOOTBRIDGE
bool "FootBridge"
select CPU_SA110
select FOOTBRIDGE
- select NEED_MACH_IO_H if !MMU
select NEED_MACH_MEMORY_H
help
Support for systems based on the DC21285 companion chip
@@ -375,7 +372,6 @@ config ARCH_FOOTBRIDGE

config ARCH_IOP32X
bool "IOP32x-based"
- depends on MMU
select CPU_XSCALE
select GPIO_IOP
select GPIOLIB
@@ -387,7 +383,6 @@ config ARCH_IOP32X

config ARCH_IXP4XX
bool "IXP4xx-based"
- depends on MMU
select ARCH_SUPPORTS_BIG_ENDIAN
select ARM_PATCH_PHYS_VIRT
select CPU_XSCALE
@@ -418,7 +413,6 @@ config ARCH_DOVE

config ARCH_PXA
bool "PXA2xx/PXA3xx-based"
- depends on MMU
select ARCH_MTD_XIP
select ARM_CPU_SUSPEND if PM
select AUTO_ZRELADDR
@@ -437,7 +431,6 @@ config ARCH_PXA

config ARCH_RPC
bool "RiscPC"
- depends on MMU
depends on !CC_IS_CLANG && GCC_VERSION < 90100 && GCC_VERSION >= 60000
select ARCH_ACORN
select ARCH_MAY_HAVE_PC_FDC
@@ -493,7 +486,6 @@ config ARCH_S3C24XX

config ARCH_OMAP1
bool "TI OMAP1"
- depends on MMU
select ARCH_OMAP
select CLKSRC_MMIO
select GENERIC_IRQ_CHIP
diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
index bd3f82788ebc..8db655c3e321 100644
--- a/arch/arm/mach-bcm/Kconfig
+++ b/arch/arm/mach-bcm/Kconfig
@@ -185,7 +185,6 @@ config ARCH_BCM_53573
config ARCH_BCM_63XX
bool "Broadcom BCM63xx DSL SoC"
depends on ARCH_MULTI_V7
- depends on MMU
select ARCH_HAS_RESET_CONTROLLER
select ARM_ERRATA_754322
select ARM_ERRATA_764369 if SMP
diff --git a/arch/arm/mach-footbridge/include/mach/hardware.h b/arch/arm/mach-footbridge/include/mach/hardware.h
index ecaf6e7388d9..985ad3a95671 100644
--- a/arch/arm/mach-footbridge/include/mach/hardware.h
+++ b/arch/arm/mach-footbridge/include/mach/hardware.h
@@ -21,32 +21,26 @@
* 0xf0000000 0x80000000 16MB ISA memory
*/

-#ifdef CONFIG_MMU
-#define MMU_IO(a, b) (a)
-#else
-#define MMU_IO(a, b) (b)
-#endif
-
#define XBUS_SIZE 0x00100000
-#define XBUS_BASE MMU_IO(0xff800000, 0x40000000)
+#define XBUS_BASE 0xff800000

#define ARMCSR_SIZE 0x00100000
-#define ARMCSR_BASE MMU_IO(0xfe000000, 0x42000000)
+#define ARMCSR_BASE 0xfe000000

#define WFLUSH_SIZE 0x00100000
-#define WFLUSH_BASE MMU_IO(0xfd000000, 0x78000000)
+#define WFLUSH_BASE 0xfd000000

#define PCIIACK_SIZE 0x00100000
-#define PCIIACK_BASE MMU_IO(0xfc000000, 0x79000000)
+#define PCIIACK_BASE 0xfc000000

#define PCICFG1_SIZE 0x01000000
-#define PCICFG1_BASE MMU_IO(0xfb000000, 0x7a000000)
+#define PCICFG1_BASE 0xfb000000

#define PCICFG0_SIZE 0x01000000
-#define PCICFG0_BASE MMU_IO(0xfa000000, 0x7b000000)
+#define PCICFG0_BASE 0xfa000000

#define PCIMEM_SIZE 0x01000000
-#define PCIMEM_BASE MMU_IO(0xf0000000, 0x80000000)
+#define PCIMEM_BASE 0xf0000000

#define XBUS_CS2 0x40012000

diff --git a/arch/arm/mach-footbridge/include/mach/io.h b/arch/arm/mach-footbridge/include/mach/io.h
deleted file mode 100644
index 4e18b921373f..000000000000
--- a/arch/arm/mach-footbridge/include/mach/io.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * arch/arm/mach-footbridge/include/mach/io.h
- *
- * Copyright (C) 1997-1999 Russell King
- *
- * Modifications:
- * 06-12-1997 RMK Created.
- * 07-04-1999 RMK Major cleanup
- */
-#ifndef __ASM_ARM_ARCH_IO_H
-#define __ASM_ARM_ARCH_IO_H
-
-/*
- * Translation of various i/o addresses to host addresses for !CONFIG_MMU
- */
-#define PCIO_BASE 0x7c000000
-#define __io(a) ((void __iomem *)(PCIO_BASE + (a)))
-
-#endif
diff --git a/arch/arm/mach-integrator/Kconfig b/arch/arm/mach-integrator/Kconfig
index 63a0ca82659a..d61ea616cf8e 100644
--- a/arch/arm/mach-integrator/Kconfig
+++ b/arch/arm/mach-integrator/Kconfig
@@ -42,24 +42,12 @@ config INTEGRATOR_IMPD1
allows ARM(R) Ltd PrimeCells to be developed and evaluated.
The IM-PD1 can be found on the Integrator/PP2 platform.

-config INTEGRATOR_CM7TDMI
- bool "Integrator/CM7TDMI core module"
- depends on ARCH_INTEGRATOR_AP
- depends on ARCH_MULTI_V4 && !MMU
- select CPU_ARM7TDMI
-
config INTEGRATOR_CM720T
bool "Integrator/CM720T core module"
depends on ARCH_INTEGRATOR_AP
depends on ARCH_MULTI_V4T
select CPU_ARM720T

-config INTEGRATOR_CM740T
- bool "Integrator/CM740T core module"
- depends on ARCH_INTEGRATOR_AP
- depends on ARCH_MULTI_V4T && !MMU
- select CPU_ARM740T
-
config INTEGRATOR_CM920T
bool "Integrator/CM920T core module"
depends on ARCH_INTEGRATOR_AP
@@ -78,23 +66,6 @@ config INTEGRATOR_CM926EJS
depends on ARCH_MULTI_V5
select CPU_ARM926T

-config INTEGRATOR_CM940T
- bool "Integrator/CM940T core module"
- depends on ARCH_INTEGRATOR_AP
- depends on ARCH_MULTI_V4T && !MMU
- select CPU_ARM940T
-
-config INTEGRATOR_CM946ES
- bool "Integrator/CM946E-S core module"
- depends on ARCH_INTEGRATOR_AP
- depends on ARCH_MULTI_V5 && !MMU
- select CPU_ARM946E
-
-config INTEGRATOR_CM966ES
- bool "Integrator/CM966E-S core module"
- depends on ARCH_INTEGRATOR_AP
- depends on BROKEN # no kernel support
-
config INTEGRATOR_CM10200E_REV0
bool "Integrator/CM10200E rev.0 core module"
depends on ARCH_INTEGRATOR_AP && n
@@ -127,7 +98,7 @@ config INTEGRATOR_CM1136JFS

config ARCH_INTEGRATOR_CP
bool "Support Integrator/CP platform"
- depends on (!MMU || ARCH_MULTI_V5 || ARCH_MULTI_V6)
+ depends on ARCH_MULTI_V5 || ARCH_MULTI_V6
select ARM_TIMER_SP804
select SERIAL_AMBA_PL011 if TTY
select SERIAL_AMBA_PL011_CONSOLE if TTY
@@ -135,12 +106,6 @@ config ARCH_INTEGRATOR_CP
help
Include support for the ARM(R) Integrator CP platform.

-config INTEGRATOR_CT7T
- bool "Integrator/CT7TD (ARM7TDMI) core tile"
- depends on ARCH_INTEGRATOR_CP
- depends on ARCH_MULTI_V4T && !MMU
- select CPU_ARM7TDMI
-
config INTEGRATOR_CT926
bool "Integrator/CT926 (ARM926EJ-S) core tile"
depends on ARCH_INTEGRATOR_CP
diff --git a/arch/arm/mach-integrator/hardware.h b/arch/arm/mach-integrator/hardware.h
index 4d6ade3dd4ee..81ce09e3ad45 100644
--- a/arch/arm/mach-integrator/hardware.h
+++ b/arch/arm/mach-integrator/hardware.h
@@ -16,12 +16,7 @@
#define IO_START INTEGRATOR_HDR_BASE // PA of IO

/* macro to get at IO space when running virtually */
-#ifdef CONFIG_MMU
#define IO_ADDRESS(x) (((x) & 0x000fffff) | (((x) >> 4) & 0x0ff00000) | IO_BASE)
-#else
-#define IO_ADDRESS(x) (x)
-#endif
-
#define __io_address(n) ((void __iomem *)IO_ADDRESS(n))

/*
diff --git a/arch/arm/mach-nspire/Kconfig b/arch/arm/mach-nspire/Kconfig
index b3d161e8e2fb..6ef1b167619b 100644
--- a/arch/arm/mach-nspire/Kconfig
+++ b/arch/arm/mach-nspire/Kconfig
@@ -2,7 +2,6 @@
config ARCH_NSPIRE
bool "TI-NSPIRE based"
depends on ARCH_MULTI_V4_V5
- depends on MMU
select CPU_ARM926T
select GENERIC_IRQ_CHIP
select ARM_AMBA
diff --git a/arch/arm/mach-orion5x/Kconfig b/arch/arm/mach-orion5x/Kconfig
index e94a61901ffd..c77f3b4e287b 100644
--- a/arch/arm/mach-orion5x/Kconfig
+++ b/arch/arm/mach-orion5x/Kconfig
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
menuconfig ARCH_ORION5X
bool "Marvell Orion"
- depends on MMU && ARCH_MULTI_V5
+ depends on ARCH_MULTI_V5
select CPU_FEROCEON
select GPIOLIB
select MVEBU_MBUS
diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig
index 3683d6f10973..50909c4b95b2 100644
--- a/arch/arm/mach-shmobile/Kconfig
+++ b/arch/arm/mach-shmobile/Kconfig
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
menuconfig ARCH_RENESAS
bool "Renesas ARM SoCs"
- depends on ARCH_MULTI_V7 && MMU
+ depends on ARCH_MULTI_V7
select ARM_GIC
select GPIOLIB
select NO_IOPORT_MAP
diff --git a/arch/arm/mach-ux500/Kconfig b/arch/arm/mach-ux500/Kconfig
index 24ed7f4a87a4..c18def269137 100644
--- a/arch/arm/mach-ux500/Kconfig
+++ b/arch/arm/mach-ux500/Kconfig
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
menuconfig ARCH_U8500
bool "ST-Ericsson U8500 Series"
- depends on ARCH_MULTI_V7 && MMU
+ depends on ARCH_MULTI_V7
select AB8500_CORE
select ABX500_CORE
select ARM_AMBA
--
2.29.2

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