[PATCH 2/2] ARM: remove support for NOMMU ARMv4/v5
From: Arnd Bergmann
Date: Wed Mar 09 2022 - 09:42:48 EST
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.
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 +++++++------------
.../mach-footbridge/include/mach/hardware.h | 20 ++++-------
arch/arm/mach-footbridge/include/mach/io.h | 20 -----------
arch/arm/mach-integrator/hardware.h | 5 ---
4 files changed, 20 insertions(+), 59 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-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/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))
/*
--
2.29.2