microblaze: Remove noMMU code

This configuration is obsolete and likely none is really using it. That's
why remove it to simplify code.

Note about CONFIG_MMU in hw_exception_handler.S is left intentionally
for better comment understanding.

Cc: Mike Rapoport <rppt@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/43486cab370e0c0a79860120b71e0caac75a7e44.1606397528.git.michal.simek@xilinx.com

arch/microblaze/Kconfig

@@ -3,19 +3,17 @@ config MICROBLAZE
 	def_bool y
 	select ARCH_32BIT_OFF_T
 	select ARCH_NO_SWAP
-	select ARCH_HAS_BINFMT_FLAT if !MMU
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
-	select ARCH_HAS_DMA_SET_UNCACHED if !MMU
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select BUILDTIME_TABLE_SORT
 	select TIMER_OF
 	select CLONE_BACKWARDS3
 	select COMMON_CLK
-	select DMA_DIRECT_REMAP if MMU
+	select DMA_DIRECT_REMAP
 	select GENERIC_ATOMIC64
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_CPU_DEVICES
@@ -45,7 +43,7 @@ config MICROBLAZE
 	select TRACING_SUPPORT
 	select VIRT_TO_BUS
 	select CPU_NO_EFFICIENT_FFS
-	select MMU_GATHER_NO_RANGE if MMU
+	select MMU_GATHER_NO_RANGE
 	select SPARSE_IRQ
 	select SET_FS
 
@@ -96,8 +94,7 @@ menu "Processor type and features"
 source "kernel/Kconfig.hz"
 
 config MMU
-	bool "MMU support"
-	default n
+	def_bool y
 
 comment "Boot options"
 
@@ -143,18 +140,8 @@ config ADVANCED_OPTIONS
 comment "Default settings for advanced configuration options are used"
 	depends on !ADVANCED_OPTIONS
 
-config XILINX_UNCACHED_SHADOW
-	bool "Are you using uncached shadow for RAM ?"
-	depends on ADVANCED_OPTIONS && !MMU
-	default n
-	help
-	  This is needed to be able to allocate uncachable memory regions.
-	  The feature requires the design to define the RAM memory controller
-	  window to be twice as large as the actual physical memory.
-
 config HIGHMEM
 	bool "High memory support"
-	depends on MMU
 	help
 	  The address space of Microblaze processors is only 4 Gigabytes large
 	  and it has to accommodate user address space, kernel address
@@ -167,7 +154,7 @@ config HIGHMEM
 
 config LOWMEM_SIZE_BOOL
 	bool "Set maximum low memory"
-	depends on ADVANCED_OPTIONS && MMU
+	depends on ADVANCED_OPTIONS
 	help
 	  This option allows you to set the maximum amount of memory which
 	  will be used as "low memory", that is, memory which the kernel can
@@ -205,12 +192,11 @@ config KERNEL_START_BOOL
 
 config KERNEL_START
 	hex "Virtual address of kernel base" if KERNEL_START_BOOL
-	default "0xc0000000" if MMU
-	default KERNEL_BASE_ADDR if !MMU
+	default "0xc0000000"
 
 config TASK_SIZE_BOOL
 	bool "Set custom user task size"
-	depends on ADVANCED_OPTIONS && MMU
+	depends on ADVANCED_OPTIONS
 	help
 	  This option allows you to set the amount of virtual address space
 	  allocated to user tasks.  This can be useful in optimizing the
@@ -222,33 +208,6 @@ config TASK_SIZE
 	hex "Size of user task space" if TASK_SIZE_BOOL
 	default "0x80000000"
 
-choice
-	prompt "Page size"
-	default MICROBLAZE_4K_PAGES
-	depends on ADVANCED_OPTIONS && !MMU
-	help
-	  Select the kernel logical page size. Increasing the page size
-	  will reduce software overhead at each page boundary, allow
-	  hardware prefetch mechanisms to be more effective, and allow
-	  larger dma transfers increasing IO efficiency and reducing
-	  overhead. However the utilization of memory will increase.
-	  For example, each cached file will using a multiple of the
-	  page size to hold its contents and the difference between the
-	  end of file and the end of page is wasted.
-
-	  If unsure, choose 4K_PAGES.
-
-config MICROBLAZE_4K_PAGES
-	bool "4k page size"
-
-config MICROBLAZE_16K_PAGES
-	bool "16k page size"
-
-config MICROBLAZE_64K_PAGES
-	bool "64k page size"
-
-endchoice
-
 endmenu
 
 menu "Bus Options"

arch/microblaze/Makefile

 # SPDX-License-Identifier: GPL-2.0
 KBUILD_DEFCONFIG := mmu_defconfig
 
-ifeq ($(CONFIG_MMU),y)
 UTS_SYSNAME = -DUTS_SYSNAME=\"Linux\"
-else
-UTS_SYSNAME = -DUTS_SYSNAME=\"uClinux\"
-endif
 
 # What CPU vesion are we building for, and crack it open
 # as major.minor.rev
@@ -67,12 +63,7 @@ DTB:=$(subst simpleImage.,,$(filter simpleImage.%, $(MAKECMDGOALS)))
 
 core-y	+= $(boot)/dts/
 
-# defines filename extension depending memory management type
-ifeq ($(CONFIG_MMU),)
-MMU := -nommu
-endif
-
-export MMU DTB
+export DTB
 
 all: linux.bin
 

arch/microblaze/configs/mmu_defconfig

@@ -16,7 +16,6 @@ CONFIG_XILINX_MICROBLAZE0_USE_DIV=1
 CONFIG_XILINX_MICROBLAZE0_USE_HW_MUL=2
 CONFIG_XILINX_MICROBLAZE0_USE_FPU=2
 CONFIG_HZ_100=y
-CONFIG_MMU=y
 CONFIG_CMDLINE_BOOL=y
 CONFIG_CMDLINE_FORCE=y
 CONFIG_HIGHMEM=y

arch/microblaze/configs/nommu_defconfig

-CONFIG_SYSVIPC=y
-CONFIG_POSIX_MQUEUE=y
-CONFIG_AUDIT=y
-CONFIG_BSD_PROCESS_ACCT=y
-CONFIG_BSD_PROCESS_ACCT_V3=y
-CONFIG_IKCONFIG=y
-CONFIG_IKCONFIG_PROC=y
-CONFIG_SYSFS_DEPRECATED=y
-CONFIG_SYSFS_DEPRECATED_V2=y
-# CONFIG_BASE_FULL is not set
-CONFIG_KALLSYMS_ALL=y
-CONFIG_EMBEDDED=y
-CONFIG_SLAB=y
-CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR=1
-CONFIG_XILINX_MICROBLAZE0_USE_PCMP_INSTR=1
-CONFIG_XILINX_MICROBLAZE0_USE_BARREL=1
-CONFIG_XILINX_MICROBLAZE0_USE_DIV=1
-CONFIG_XILINX_MICROBLAZE0_USE_HW_MUL=2
-CONFIG_XILINX_MICROBLAZE0_USE_FPU=2
-CONFIG_HZ_100=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE_FORCE=y
-CONFIG_PCI_XILINX=y
-CONFIG_MODULES=y
-CONFIG_MODULE_UNLOAD=y
-# CONFIG_BLK_DEV_BSG is not set
-CONFIG_PARTITION_ADVANCED=y
-# CONFIG_EFI_PARTITION is not set
-CONFIG_NET=y
-CONFIG_PACKET=y
-CONFIG_UNIX=y
-CONFIG_INET=y
-# CONFIG_IPV6 is not set
-CONFIG_PCI=y
-CONFIG_MTD=y
-CONFIG_MTD_CMDLINE_PARTS=y
-CONFIG_MTD_BLOCK=y
-CONFIG_MTD_CFI=y
-CONFIG_MTD_CFI_INTELEXT=y
-CONFIG_MTD_CFI_AMDSTD=y
-CONFIG_MTD_RAM=y
-CONFIG_MTD_UCLINUX=y
-CONFIG_BLK_DEV_RAM=y
-CONFIG_BLK_DEV_RAM_SIZE=8192
-CONFIG_NETDEVICES=y
-CONFIG_XILINX_EMACLITE=y
-CONFIG_XILINX_LL_TEMAC=y
-# CONFIG_INPUT is not set
-# CONFIG_SERIO is not set
-# CONFIG_VT is not set
-CONFIG_SERIAL_8250=y
-CONFIG_SERIAL_8250_CONSOLE=y
-CONFIG_SERIAL_OF_PLATFORM=y
-CONFIG_SERIAL_UARTLITE=y
-CONFIG_SERIAL_UARTLITE_CONSOLE=y
-# CONFIG_HW_RANDOM is not set
-CONFIG_XILINX_HWICAP=y
-CONFIG_I2C=y
-CONFIG_I2C_XILINX=y
-CONFIG_SPI=y
-CONFIG_SPI_XILINX=y
-CONFIG_GPIOLIB=y
-CONFIG_GPIO_SYSFS=y
-CONFIG_GPIO_XILINX=y
-CONFIG_POWER_RESET=y
-CONFIG_POWER_RESET_GPIO_RESTART=y
-# CONFIG_HWMON is not set
-CONFIG_WATCHDOG=y
-CONFIG_XILINX_WATCHDOG=y
-CONFIG_FB=y
-CONFIG_FB_XILINX=y
-# CONFIG_USB_SUPPORT is not set
-CONFIG_EXT3_FS=y
-# CONFIG_DNOTIFY is not set
-CONFIG_CRAMFS=y
-CONFIG_ROMFS_FS=y
-CONFIG_NFS_FS=y
-CONFIG_NFS_V3_ACL=y
-CONFIG_NLS=y
-CONFIG_KEYS=y
-CONFIG_ENCRYPTED_KEYS=y
-CONFIG_CRYPTO_ECB=y
-CONFIG_CRYPTO_MD4=y
-CONFIG_CRYPTO_MD5=y
-CONFIG_CRYPTO_ARC4=y
-CONFIG_CRYPTO_DES=y
-CONFIG_DEBUG_INFO=y
-CONFIG_DEBUG_SLAB=y
-CONFIG_DETECT_HUNG_TASK=y
-CONFIG_DEBUG_SPINLOCK=y

arch/microblaze/include/asm/dma.h

@@ -6,14 +6,8 @@
 #ifndef _ASM_MICROBLAZE_DMA_H
 #define _ASM_MICROBLAZE_DMA_H
 
-#ifndef CONFIG_MMU
-/* we don't have dma address limit. define it as zero to be
- * unlimited. */
-#define MAX_DMA_ADDRESS		(0)
-#else
 /* Virtual address corresponding to last available physical memory address.  */
 #define MAX_DMA_ADDRESS (CONFIG_KERNEL_START + memory_size - 1)
-#endif
 
 #ifdef CONFIG_PCI
 extern int isa_dma_bridge_buggy;

arch/microblaze/include/asm/exceptions.h

@@ -11,11 +11,6 @@
 #define _ASM_MICROBLAZE_EXCEPTIONS_H
 
 #ifdef __KERNEL__
-
-#ifndef CONFIG_MMU
-#define EX_HANDLER_STACK_SIZ	(4*19)
-#endif
-
 #ifndef __ASSEMBLY__
 
 /* Macros to enable and disable HW exceptions in the MSR */

arch/microblaze/include/asm/io.h

@@ -30,15 +30,12 @@ extern resource_size_t isa_mem_base;
 #define PCI_IOBASE	((void __iomem *)_IO_BASE)
 #define IO_SPACE_LIMIT (0xFFFFFFFF)
 
-#ifdef CONFIG_MMU
 #define page_to_bus(page)	(page_to_phys(page))
 
 extern void iounmap(volatile void __iomem *addr);
 
 extern void __iomem *ioremap(phys_addr_t address, unsigned long size);
 
-#endif /* CONFIG_MMU */
-
 /* Big Endian */
 #define out_be32(a, v) __raw_writel((v), (void __iomem __force *)(a))
 #define out_be16(a, v) __raw_writew((v), (a))

arch/microblaze/include/asm/mmu.h

@@ -8,9 +8,6 @@
 #ifndef _ASM_MICROBLAZE_MMU_H
 #define _ASM_MICROBLAZE_MMU_H
 
-# ifndef CONFIG_MMU
-#  include <asm-generic/mmu.h>
-# else /* CONFIG_MMU */
 #  ifdef __KERNEL__
 #   ifndef __ASSEMBLY__
 
@@ -119,5 +116,4 @@ extern u32 tlb_skip;
 #  define TLB_G			0x00000001 /* Memory is guarded from prefetch */
 
 #  endif /* __KERNEL__ */
-# endif /* CONFIG_MMU */
 #endif /* _ASM_MICROBLAZE_MMU_H */

arch/microblaze/include/asm/mmu_context.h

 /* SPDX-License-Identifier: GPL-2.0 */
-#ifdef CONFIG_MMU
 # include <asm/mmu_context_mm.h>
-#else
-# include <asm-generic/mmu_context.h>
-#endif

arch/microblaze/include/asm/page.h

@@ -20,13 +20,7 @@
 #ifdef __KERNEL__
 
 /* PAGE_SHIFT determines the page size */
-#if defined(CONFIG_MICROBLAZE_64K_PAGES)
-#define PAGE_SHIFT		16
-#elif defined(CONFIG_MICROBLAZE_16K_PAGES)
-#define PAGE_SHIFT		14
-#else
 #define PAGE_SHIFT		12
-#endif
 #define PAGE_SIZE	(ASM_CONST(1) << PAGE_SHIFT)
 #define PAGE_MASK	(~(PAGE_SIZE-1))
 
@@ -44,17 +38,6 @@
 #define PAGE_UP(addr)	(((addr)+((PAGE_SIZE)-1))&(~((PAGE_SIZE)-1)))
 #define PAGE_DOWN(addr)	((addr)&(~((PAGE_SIZE)-1)))
 
-#ifndef CONFIG_MMU
-/*
- * PAGE_OFFSET -- the first address of the first page of memory. When not
- * using MMU this corresponds to the first free page in physical memory (aligned
- * on a page boundary).
- */
-extern unsigned int __page_offset;
-#define PAGE_OFFSET __page_offset
-
-#else /* CONFIG_MMU */
-
 /*
  * PAGE_OFFSET -- the first address of the first page of memory. With MMU
  * it is set to the kernel start address (aligned on a page boundary).
@@ -70,8 +53,6 @@ extern unsigned int __page_offset;
 typedef unsigned long pte_basic_t;
 #define PTE_FMT		"%.8lx"
 
-#endif /* CONFIG_MMU */
-
 # define copy_page(to, from)			memcpy((to), (from), PAGE_SIZE)
 # define clear_page(pgaddr)			memset((pgaddr), 0, PAGE_SIZE)
 
@@ -86,25 +67,12 @@ typedef struct page *pgtable_t;
 typedef struct { unsigned long	pte; }		pte_t;
 typedef struct { unsigned long	pgprot; }	pgprot_t;
 /* FIXME this can depend on linux kernel version */
-#   ifdef CONFIG_MMU
 typedef struct { unsigned long pgd; } pgd_t;
-#   else /* CONFIG_MMU */
-typedef struct { unsigned long	ste[64]; }	pmd_t;
-typedef struct { pmd_t		pue[1]; }	pud_t;
-typedef struct { pud_t		p4e[1]; }	p4d_t;
-typedef struct { p4d_t		pge[1]; }	pgd_t;
-#   endif /* CONFIG_MMU */
 
 # define pte_val(x)	((x).pte)
 # define pgprot_val(x)	((x).pgprot)
 
-#   ifdef CONFIG_MMU
 #   define pgd_val(x)      ((x).pgd)
-#   else  /* CONFIG_MMU */
-#   define pmd_val(x)	((x).ste[0])
-#   define pud_val(x)	((x).pue[0])
-#   define pgd_val(x)	((x).pge[0])
-#   endif  /* CONFIG_MMU */
 
 # define __pte(x)	((pte_t) { (x) })
 # define __pgd(x)	((pgd_t) { (x) })
@@ -142,28 +110,12 @@ extern int page_is_ram(unsigned long pfn);
 # define virt_to_pfn(vaddr)	(phys_to_pfn((__pa(vaddr))))
 # define pfn_to_virt(pfn)	__va(pfn_to_phys((pfn)))
 
-#  ifdef CONFIG_MMU
-
 #  define virt_to_page(kaddr)	(pfn_to_page(__pa(kaddr) >> PAGE_SHIFT))
 #  define page_to_virt(page)   __va(page_to_pfn(page) << PAGE_SHIFT)
 #  define page_to_phys(page)     (page_to_pfn(page) << PAGE_SHIFT)
 
-#  else /* CONFIG_MMU */
-#  define virt_to_page(vaddr)	(pfn_to_page(virt_to_pfn(vaddr)))
-#  define page_to_virt(page)	(pfn_to_virt(page_to_pfn(page)))
-#  define page_to_phys(page)	(pfn_to_phys(page_to_pfn(page)))
-#  define page_to_bus(page)	(page_to_phys(page))
-#  define phys_to_page(paddr)	(pfn_to_page(phys_to_pfn(paddr)))
-#  endif /* CONFIG_MMU */
-
-#  ifndef CONFIG_MMU
-#  define pfn_valid(pfn)	(((pfn) >= min_low_pfn) && \
-				((pfn) <= (min_low_pfn + max_mapnr)))
-#  define ARCH_PFN_OFFSET	(PAGE_OFFSET >> PAGE_SHIFT)
-#  else /* CONFIG_MMU */
 #  define ARCH_PFN_OFFSET	(memory_start >> PAGE_SHIFT)
 #  define pfn_valid(pfn)	((pfn) < (max_mapnr + ARCH_PFN_OFFSET))
-#  endif /* CONFIG_MMU */
 
 # endif /* __ASSEMBLY__ */
 
@@ -174,12 +126,6 @@ extern int page_is_ram(unsigned long pfn);
 
 /* Convert between virtual and physical address for MMU. */
 /* Handle MicroBlaze processor with virtual memory. */
-#ifndef CONFIG_MMU
-#define __virt_to_phys(addr)	addr
-#define __phys_to_virt(addr)	addr
-#define tophys(rd, rs)	addik rd, rs, 0
-#define tovirt(rd, rs)	addik rd, rs, 0
-#else
 #define __virt_to_phys(addr) \
 	((addr) + CONFIG_KERNEL_BASE_ADDR - CONFIG_KERNEL_START)
 #define __phys_to_virt(addr) \
@@ -188,14 +134,9 @@ extern int page_is_ram(unsigned long pfn);
 	addik rd, rs, (CONFIG_KERNEL_BASE_ADDR - CONFIG_KERNEL_START)
 #define tovirt(rd, rs) \
 	addik rd, rs, (CONFIG_KERNEL_START - CONFIG_KERNEL_BASE_ADDR)
-#endif /* CONFIG_MMU */
 
 #define TOPHYS(addr)  __virt_to_phys(addr)
 
-#ifdef CONFIG_MMU
-
-#endif /* CONFIG_MMU */
-
 #endif /* __KERNEL__ */
 
 #include <asm-generic/memory_model.h>

arch/microblaze/include/asm/pgalloc.h

@@ -8,8 +8,6 @@
 #ifndef _ASM_MICROBLAZE_PGALLOC_H
 #define _ASM_MICROBLAZE_PGALLOC_H
 
-#ifdef CONFIG_MMU
-
 #include <linux/kernel.h>	/* For min/max macros */
 #include <linux/highmem.h>
 #include <linux/pgtable.h>
@@ -42,6 +40,4 @@ extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm);
 #define pmd_populate_kernel(mm, pmd, pte) \
 		(pmd_val(*(pmd)) = (unsigned long) (pte))
 
-#endif /* CONFIG_MMU */
-
 #endif /* _ASM_MICROBLAZE_PGALLOC_H */

arch/microblaze/include/asm/pgtable.h

@@ -14,47 +14,6 @@
 extern int mem_init_done;
 #endif
 
-#ifndef CONFIG_MMU
-
-#define pgd_present(pgd)	(1) /* pages are always present on non MMU */
-#define pgd_none(pgd)		(0)
-#define pgd_bad(pgd)		(0)
-#define pgd_clear(pgdp)
-#define kern_addr_valid(addr)	(1)
-
-#define PAGE_NONE		__pgprot(0) /* these mean nothing to non MMU */
-#define PAGE_SHARED		__pgprot(0) /* these mean nothing to non MMU */
-#define PAGE_COPY		__pgprot(0) /* these mean nothing to non MMU */
-#define PAGE_READONLY		__pgprot(0) /* these mean nothing to non MMU */
-#define PAGE_KERNEL		__pgprot(0) /* these mean nothing to non MMU */
-
-#define pgprot_noncached(x)	(x)
-#define pgprot_writecombine	pgprot_noncached
-#define pgprot_device		pgprot_noncached
-
-#define __swp_type(x)		(0)
-#define __swp_offset(x)		(0)
-#define __swp_entry(typ, off)	((swp_entry_t) { ((typ) | ((off) << 7)) })
-#define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
-#define __swp_entry_to_pte(x)	((pte_t) { (x).val })
-
-#define ZERO_PAGE(vaddr)	({ BUG(); NULL; })
-
-#define swapper_pg_dir ((pgd_t *) NULL)
-
-#define arch_enter_lazy_cpu_mode()	do {} while (0)
-
-#define pgprot_noncached_wc(prot)	prot
-
-/*
- * All 32bit addresses are effectively valid for vmalloc...
- * Sort of meaningless for non-VM targets.
- */
-#define	VMALLOC_START	0
-#define	VMALLOC_END	0xffffffff
-
-#else /* CONFIG_MMU */
-
 #include <asm-generic/pgtable-nopmd.h>
 
 #ifdef __KERNEL__
@@ -491,8 +450,6 @@ void __init *early_get_page(void);
 #endif /* __ASSEMBLY__ */
 #endif /* __KERNEL__ */
 
-#endif /* CONFIG_MMU */
-
 #ifndef __ASSEMBLY__
 extern unsigned long ioremap_bot, ioremap_base;
 

arch/microblaze/include/asm/processor.h

@@ -31,42 +31,6 @@ extern void ret_from_kernel_thread(void);
 
 # endif /* __ASSEMBLY__ */
 
-# ifndef CONFIG_MMU
-/*
- * User space process size: memory size
- *
- * TASK_SIZE on MMU cpu is usually 1GB. However, on no-MMU arch, both
- * user processes and the kernel is on the same memory region. They
- * both share the memory space and that is limited by the amount of
- * physical memory. thus, we set TASK_SIZE == amount of total memory.
- */
-# define TASK_SIZE	(0x81000000 - 0x80000000)
-
-/*
- * This decides where the kernel will search for a free chunk of vm
- * space during mmap's. We won't be using it
- */
-# define TASK_UNMAPPED_BASE	0
-
-/* definition in include/linux/sched.h */
-struct task_struct;
-
-/* thread_struct is gone. use thread_info instead. */
-struct thread_struct { };
-# define INIT_THREAD	{ }
-
-/* Free all resources held by a thread. */
-static inline void release_thread(struct task_struct *dead_task)
-{
-}
-
-extern unsigned long get_wchan(struct task_struct *p);
-
-# define KSTK_EIP(tsk)	(0)
-# define KSTK_ESP(tsk)	(0)
-
-# else /* CONFIG_MMU */
-
 /*
  * This is used to define STACK_TOP, and with MMU it must be below
  * kernel base to select the correct PGD when handling MMU exceptions.
@@ -133,5 +97,4 @@ extern struct dentry *of_debugfs_root;
 #endif
 
 #  endif /* __ASSEMBLY__ */
-# endif /* CONFIG_MMU */
 #endif /* _ASM_MICROBLAZE_PROCESSOR_H */

arch/microblaze/include/asm/registers.h

@@ -27,7 +27,6 @@
 #define FSR_UF		(1<<1) /* Underflow */
 #define FSR_DO		(1<<0) /* Denormalized operand error */
 
-# ifdef CONFIG_MMU
 /* Machine State Register (MSR) Fields */
 # define MSR_UM		(1<<11) /* User Mode */
 # define MSR_UMS	(1<<12) /* User Mode Save */
@@ -43,5 +42,4 @@
 # define	  ESR_DIZ	(1<<11) /* Zone Protection */
 # define	  ESR_S		(1<<10) /* Store instruction */
 
-# endif /* CONFIG_MMU */
 #endif /* _ASM_MICROBLAZE_REGISTERS_H */

arch/microblaze/include/asm/setup.h

@@ -14,9 +14,7 @@ extern char cmd_line[COMMAND_LINE_SIZE];
 
 extern char *klimit;
 
-#   ifdef CONFIG_MMU
 extern void mmu_reset(void);
-#   endif /* CONFIG_MMU */
 
 void time_init(void);
 void init_IRQ(void);

arch/microblaze/include/asm/tlbflush.h

@@ -8,8 +8,6 @@
 #ifndef _ASM_MICROBLAZE_TLBFLUSH_H
 #define _ASM_MICROBLAZE_TLBFLUSH_H
 
-#ifdef CONFIG_MMU
-
 #include <linux/sched.h>
 #include <linux/threads.h>
 #include <asm/processor.h>	/* For TASK_SIZE */
@@ -50,16 +48,4 @@ static inline void local_flush_tlb_range(struct vm_area_struct *vma,
 static inline void flush_tlb_pgtables(struct mm_struct *mm,
 	unsigned long start, unsigned long end) { }
 
-#else /* CONFIG_MMU */
-
-#define flush_tlb()				BUG()
-#define flush_tlb_all()				BUG()
-#define flush_tlb_mm(mm)			BUG()
-#define flush_tlb_page(vma, addr)		BUG()
-#define flush_tlb_range(mm, start, end)		BUG()
-#define flush_tlb_pgtables(mm, start, end)	BUG()
-#define flush_tlb_kernel_range(start, end)	BUG()
-
-#endif /* CONFIG_MMU */
-
 #endif /* _ASM_MICROBLAZE_TLBFLUSH_H */

arch/microblaze/include/asm/uaccess.h

@@ -30,35 +30,14 @@
  */
 # define MAKE_MM_SEG(s)       ((mm_segment_t) { (s) })
 
-#  ifndef CONFIG_MMU
-#  define KERNEL_DS	MAKE_MM_SEG(0)
-#  define USER_DS	KERNEL_DS
-#  else
 #  define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFF)
 #  define USER_DS	MAKE_MM_SEG(TASK_SIZE - 1)
-#  endif
 
 # define get_fs()	(current_thread_info()->addr_limit)
 # define set_fs(val)	(current_thread_info()->addr_limit = (val))
 
 # define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
 
-#ifndef CONFIG_MMU
-
-/* Check against bounds of physical memory */
-static inline int ___range_ok(unsigned long addr, unsigned long size)
-{
-	return ((addr < memory_start) ||
-		((addr + size - 1) > (memory_start + memory_size - 1)));
-}
-
-#define __range_ok(addr, size) \
-		___range_ok((unsigned long)(addr), (unsigned long)(size))
-
-#define access_ok(addr, size) (__range_ok((addr), (size)) == 0)
-
-#else
-
 static inline int access_ok(const void __user *addr, unsigned long size)
 {
 	if (!size)
@@ -77,15 +56,9 @@ static inline int access_ok(const void __user *addr, unsigned long size)
 			(u32)get_fs().seg);
 	return 1;
 }
-#endif
 
-#ifdef CONFIG_MMU
 # define __FIXUP_SECTION	".section .fixup,\"ax\"\n"
 # define __EX_TABLE_SECTION	".section __ex_table,\"a\"\n"
-#else
-# define __FIXUP_SECTION	".section .discard,\"ax\"\n"
-# define __EX_TABLE_SECTION	".section .discard,\"ax\"\n"
-#endif
 
 extern unsigned long __copy_tofrom_user(void __user *to,
 		const void __user *from, unsigned long size);

arch/microblaze/kernel/Makefile

@@ -22,9 +22,9 @@ obj-y += dma.o exceptions.o \
 obj-y += cpu/
 
 obj-$(CONFIG_MODULES)		+= microblaze_ksyms.o module.o
-obj-$(CONFIG_MMU)		+= misc.o
+obj-y				+= misc.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_FUNCTION_TRACER)	+= ftrace.o mcount.o
 obj-$(CONFIG_KGDB)		+= kgdb.o
 
-obj-y	+= entry$(MMU).o
+obj-y	+= entry.o

arch/microblaze/kernel/asm-offsets.c

@@ -70,7 +70,6 @@ int main(int argc, char *argv[])
 
 	/* struct task_struct */
 	DEFINE(TS_THREAD_INFO, offsetof(struct task_struct, stack));
-#ifdef CONFIG_MMU
 	DEFINE(TASK_STATE, offsetof(struct task_struct, state));
 	DEFINE(TASK_FLAGS, offsetof(struct task_struct, flags));
 	DEFINE(TASK_PTRACE, offsetof(struct task_struct, ptrace));
@@ -84,7 +83,6 @@ int main(int argc, char *argv[])
 
 	DEFINE(PGDIR, offsetof(struct thread_struct, pgdir));
 	BLANK();
-#endif
 
 	/* struct thread_info */
 	DEFINE(TI_TASK, offsetof(struct thread_info, task));

arch/microblaze/kernel/exceptions.c

@@ -69,9 +69,7 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
 							int fsr, int addr)
 {
-#ifdef CONFIG_MMU
 	addr = regs->pc;
-#endif
 
 #if 0
 	pr_warn("Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
@@ -132,13 +130,10 @@ asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
 			fsr = FPE_FLTRES;
 		_exception(SIGFPE, regs, fsr, addr);
 		break;
-
-#ifdef CONFIG_MMU
 	case MICROBLAZE_PRIVILEGED_EXCEPTION:
 		pr_debug("Privileged exception\n");
 		_exception(SIGILL, regs, ILL_PRVOPC, addr);
 		break;
-#endif
 	default:
 	/* FIXME what to do in unexpected exception */
 		pr_warn("Unexpected exception %02x PC=%08x in %s mode\n",

arch/microblaze/kernel/head.S

@@ -34,7 +34,6 @@
 #include <asm/page.h>
 #include <linux/of_fdt.h>		/* for OF_DT_HEADER */
 
-#ifdef CONFIG_MMU
 #include <asm/setup.h> /* COMMAND_LINE_SIZE */
 #include <asm/mmu.h>
 #include <asm/processor.h>
@@ -48,8 +47,6 @@ empty_zero_page:
 swapper_pg_dir:
 	.space	PAGE_SIZE
 
-#endif /* CONFIG_MMU */
-
 .section .rodata
 .align 4
 endian_check:
@@ -108,8 +105,6 @@ _copy_fdt:
 	addik	r3, r3, -4 /* descrement loop */
 no_fdt_arg:
 
-#ifdef CONFIG_MMU
-
 #ifndef CONFIG_CMDLINE_BOOL
 /*
  * handling command line
@@ -329,7 +324,6 @@ turn_on_mmu:
 	nop
 
 start_here:
-#endif /* CONFIG_MMU */
 
 	/* Initialize small data anchors */
 	addik	r13, r0, _KERNEL_SDA_BASE_
@@ -345,11 +339,6 @@ start_here:
 	brald	r15, r11
 	nop
 
-#ifndef CONFIG_MMU
-	addik	r15, r0, machine_halt
-	braid	start_kernel
-	nop
-#else
 	/*
 	 * Initialize the MMU.
 	 */
@@ -383,4 +372,3 @@ kernel_load_context:
 	nop
 	rted	r17, 0		/* enable MMU and jump to start_kernel */
 	nop
-#endif /* CONFIG_MMU */

arch/microblaze/kernel/hw_exception_handler.S

@@ -80,7 +80,6 @@
 /* Helpful Macros */
 #define NUM_TO_REG(num)		r ## num
 
-#ifdef CONFIG_MMU
 	#define RESTORE_STATE			\
 		lwi	r5, r1, 0;		\
 		mts	rmsr, r5;		\
@@ -92,7 +91,6 @@
 		lwi	r11, r1, PT_R11;	\
 		lwi	r31, r1, PT_R31;	\
 		lwi	r1, r1, PT_R1;
-#endif /* CONFIG_MMU */
 
 #define LWREG_NOP			\
 	bri	ex_handler_unhandled;	\
@@ -102,10 +100,6 @@
 	bri	ex_handler_unhandled;	\
 	nop;
 
-/* FIXME this is weird - for noMMU kernel is not possible to use brid
- * instruction which can shorten executed time
- */
-
 /* r3 is the source */
 #define R3_TO_LWREG_V(regnum)				\
 	swi	r3, r1, 4 * regnum;				\
@@ -126,7 +120,6 @@
 	or	r3, r0, NUM_TO_REG (regnum);		\
 	bri	ex_sw_tail;
 
-#ifdef CONFIG_MMU
 	#define R3_TO_LWREG_VM_V(regnum)		\
 		brid	ex_lw_end_vm;			\
 		swi	r3, r7, 4 * regnum;
@@ -193,7 +186,6 @@
 	.endm
 	#endif
 
-#endif /* CONFIG_MMU */
 
 .extern other_exception_handler /* Defined in exception.c */
 
@@ -251,7 +243,6 @@
  */
 
 /* wrappers to restore state before coming to entry.S */
-#ifdef CONFIG_MMU
 .section .data
 .align 4
 pt_pool_space:
@@ -316,31 +307,24 @@ _MB_HW_ExceptionVectorTable:
 	.long	TOPHYS(ex_handler_unhandled)
 	.long	TOPHYS(ex_handler_unhandled)
 	.long	TOPHYS(ex_handler_unhandled)
-#endif
 
 .global _hw_exception_handler
 .section .text
 .align 4
 .ent _hw_exception_handler
 _hw_exception_handler:
-#ifndef CONFIG_MMU
-	addik	r1, r1, -(EX_HANDLER_STACK_SIZ); /* Create stack frame */
-#else
 	swi	r1, r0, TOPHYS(pt_pool_space + PT_R1); /* GET_SP */
 	/* Save date to kernel memory. Here is the problem
 	 * when you came from user space */
 	ori	r1, r0, TOPHYS(pt_pool_space);
-#endif
 	swi	r3, r1, PT_R3
 	swi	r4, r1, PT_R4
 	swi	r5, r1, PT_R5
 	swi	r6, r1, PT_R6
 
-#ifdef CONFIG_MMU
 	swi	r11, r1, PT_R11
 	swi	r31, r1, PT_R31
 	lwi	r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)) /* get saved current */
-#endif
 
 	mfs	r5, rmsr;
 	nop
@@ -350,18 +334,8 @@ _hw_exception_handler:
 	mfs	r3, rear;
 	nop
 
-#ifndef CONFIG_MMU
-	andi	r5, r4, 0x1000;		/* Check ESR[DS] */
-	beqi	r5, not_in_delay_slot;	/* Branch if ESR[DS] not set */
-	mfs	r17, rbtr;	/* ESR[DS] set - return address in BTR */
-	nop
-not_in_delay_slot:
-	swi	r17, r1, PT_R17
-#endif
-
 	andi	r5, r4, 0x1F;		/* Extract ESR[EXC] */
 
-#ifdef CONFIG_MMU
 	/* Calculate exception vector offset = r5 << 2 */
 	addk	r6, r5, r5; /* << 1 */
 	addk	r6, r6, r6; /* << 2 */
@@ -383,73 +357,6 @@ not_in_delay_slot:
 full_exception_trapw:
 	RESTORE_STATE
 	bri	full_exception_trap
-#else
-	/* Exceptions enabled here. This will allow nested exceptions */
-	mfs	r6, rmsr;
-	nop
-	swi	r6, r1, 0; /* RMSR_OFFSET */
-	ori	r6, r6, 0x100; /* Turn ON the EE bit */
-	andi	r6, r6, ~2; /* Disable interrupts */
-	mts	rmsr, r6;
-	nop
-
-	xori	r6, r5, 1; /* 00001 = Unaligned Exception */
-	/* Jump to unalignment exception handler */
-	beqi	r6, handle_unaligned_ex;
-
-handle_other_ex: /* Handle Other exceptions here */
-	/* Save other volatiles before we make procedure calls below */
-	swi	r7, r1, PT_R7
-	swi	r8, r1, PT_R8
-	swi	r9, r1, PT_R9
-	swi	r10, r1, PT_R10
-	swi	r11, r1, PT_R11
-	swi	r12, r1, PT_R12
-	swi	r14, r1, PT_R14
-	swi	r15, r1, PT_R15
-	swi	r18, r1, PT_R18
-
-	or	r5, r1, r0
-	andi	r6, r4, 0x1F; /* Load ESR[EC] */
-	lwi	r7, r0, PER_CPU(KM) /* MS: saving current kernel mode to regs */
-	swi	r7, r1, PT_MODE
-	mfs	r7, rfsr
-	nop
-	addk	r8, r17, r0; /* Load exception address */
-	bralid	r15, full_exception; /* Branch to the handler */
-	nop;
-	mts	rfsr, r0;	/* Clear sticky fsr */
-	nop
-
-	/*
-	 * Trigger execution of the signal handler by enabling
-	 * interrupts and calling an invalid syscall.
-	 */
-	mfs	r5, rmsr;
-	nop
-	ori	r5, r5, 2;
-	mts	rmsr, r5; /* enable interrupt */
-	nop
-	addi	r12, r0, __NR_syscalls;
-	brki	r14, 0x08;
-	mfs	r5, rmsr; /* disable interrupt */
-	nop
-	andi	r5, r5, ~2;
-	mts	rmsr, r5;
-	nop
-
-	lwi	r7, r1, PT_R7
-	lwi	r8, r1, PT_R8
-	lwi	r9, r1, PT_R9
-	lwi	r10, r1, PT_R10
-	lwi	r11, r1, PT_R11
-	lwi	r12, r1, PT_R12
-	lwi	r14, r1, PT_R14
-	lwi	r15, r1, PT_R15
-	lwi	r18, r1, PT_R18
-
-	bri	ex_handler_done; /* Complete exception handling */
-#endif
 
 /* 0x01 - Unaligned data access exception
  * This occurs when a word access is not aligned on a word boundary,
@@ -463,7 +370,6 @@ handle_unaligned_ex:
 	 *  R4 = ESR
 	 *  R3 = EAR
 	 */
-#ifdef CONFIG_MMU
 	andi	r6, r4, 0x1000			/* Check ESR[DS] */
 	beqi	r6, _no_delayslot		/* Branch if ESR[DS] not set */
 	mfs	r17, rbtr;	/* ESR[DS] set - return address in BTR */
@@ -472,7 +378,7 @@ _no_delayslot:
 	/* jump to high level unaligned handler */
 	RESTORE_STATE;
 	bri	unaligned_data_trap
-#endif
+
 	andi	r6, r4, 0x3E0; /* Mask and extract the register operand */
 	srl	r6, r6; /* r6 >> 5 */
 	srl	r6, r6;
@@ -558,25 +464,10 @@ ex_shw:
 ex_sw_end: /* Exception handling of store word, ends. */
 
 ex_handler_done:
-#ifndef CONFIG_MMU
-	lwi	r5, r1, 0 /* RMSR */
-	mts	rmsr, r5
-	nop
-	lwi	r3, r1, PT_R3
-	lwi	r4, r1, PT_R4
-	lwi	r5, r1, PT_R5
-	lwi	r6, r1, PT_R6
-	lwi	r17, r1, PT_R17
-
-	rted	r17, 0
-	addik	r1, r1, (EX_HANDLER_STACK_SIZ); /* Restore stack frame */
-#else
 	RESTORE_STATE;
 	rted	r17, 0
 	nop
-#endif
 
-#ifdef CONFIG_MMU
 	/* Exception vector entry code. This code runs with address translation
 	 * turned off (i.e. using physical addresses). */
 
@@ -882,13 +773,7 @@ ex_handler_done:
 		 * bits 20 and 21 are zero.
 		 */
 		andi	r3, r3, PAGE_MASK
-#ifdef CONFIG_MICROBLAZE_64K_PAGES
-		ori	r3, r3, TLB_VALID | TLB_PAGESZ(PAGESZ_64K)
-#elif CONFIG_MICROBLAZE_16K_PAGES
-		ori	r3, r3, TLB_VALID | TLB_PAGESZ(PAGESZ_16K)
-#else
 		ori	r3, r3, TLB_VALID | TLB_PAGESZ(PAGESZ_4K)
-#endif
 		mts	rtlbhi,	r3		/* Load TLB HI */
 		nop
 
@@ -926,10 +811,8 @@ ex_handler_done:
 		rtsd	r15,8
 		nop
 
-#endif
 .end _hw_exception_handler
 
-#ifdef CONFIG_MMU
 /* Unaligned data access exception last on a 4k page for MMU.
  * When this is called, we are in virtual mode with exceptions enabled
  * and registers 1-13,15,17,18 saved.
@@ -1044,7 +927,6 @@ ex_unaligned_fixup:
 	.word	store6,ex_unaligned_fixup;
 .previous;
 .end _unaligned_data_exception
-#endif /* CONFIG_MMU */
 
 .global ex_handler_unhandled
 ex_handler_unhandled:
@@ -1093,11 +975,7 @@ lw_r27:		R3_TO_LWREG	(27);
 lw_r28:		R3_TO_LWREG	(28);
 lw_r29:		R3_TO_LWREG	(29);
 lw_r30:		R3_TO_LWREG	(30);
-#ifdef CONFIG_MMU
 lw_r31: 	R3_TO_LWREG_V	(31);
-#else
-lw_r31:		R3_TO_LWREG	(31);
-#endif
 
 sw_table:
 sw_r0:		SWREG_TO_R3	(0);
@@ -1131,13 +1009,8 @@ sw_r27:		SWREG_TO_R3	(27);
 sw_r28:		SWREG_TO_R3	(28);
 sw_r29:		SWREG_TO_R3	(29);
 sw_r30:		SWREG_TO_R3	(30);
-#ifdef CONFIG_MMU
 sw_r31:		SWREG_TO_R3_V	(31);
-#else
-sw_r31:		SWREG_TO_R3	(31);
-#endif
 
-#ifdef CONFIG_MMU
 lw_table_vm:
 lw_r0_vm:	R3_TO_LWREG_VM		(0);
 lw_r1_vm:	R3_TO_LWREG_VM_V	(1);
@@ -1205,7 +1078,6 @@ sw_r28_vm:	SWREG_TO_R3_VM_V	(28);
 sw_r29_vm:	SWREG_TO_R3_VM_V	(29);
 sw_r30_vm:	SWREG_TO_R3_VM_V	(30);
 sw_r31_vm:	SWREG_TO_R3_VM_V	(31);
-#endif /* CONFIG_MMU */
 
 /* Temporary data structures used in the handler */
 .section .data

arch/microblaze/kernel/microblaze_ksyms.c

@@ -33,9 +33,7 @@ EXPORT_SYMBOL(memcpy);
 EXPORT_SYMBOL(memmove);
 #endif
 
-#ifdef CONFIG_MMU
 EXPORT_SYMBOL(empty_zero_page);
-#endif
 
 EXPORT_SYMBOL(mbc);
 

arch/microblaze/kernel/process.c

@@ -69,9 +69,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
 		ti->cpu_context.r19 = (unsigned long)arg;
 		childregs->pt_mode = 1;
 		local_save_flags(childregs->msr);
-#ifdef CONFIG_MMU
 		ti->cpu_context.msr = childregs->msr & ~MSR_IE;
-#endif
 		ti->cpu_context.r15 = (unsigned long)ret_from_kernel_thread - 8;
 		return 0;
 	}
@@ -81,9 +79,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
 
 	memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
 	ti->cpu_context.r1 = (unsigned long)childregs;
-#ifndef CONFIG_MMU
-	ti->cpu_context.msr = (unsigned long)childregs->msr;
-#else
 	childregs->msr |= MSR_UMS;
 
 	/* we should consider the fact that childregs is a copy of the parent
@@ -105,7 +100,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
 	ti->cpu_context.msr = (childregs->msr|MSR_VM);
 	ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
 	ti->cpu_context.msr &= ~MSR_IE;
-#endif
 	ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
 
 	/*
@@ -130,13 +124,10 @@ void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
 	regs->pc = pc;
 	regs->r1 = usp;
 	regs->pt_mode = 0;
-#ifdef CONFIG_MMU
 	regs->msr |= MSR_UMS;
 	regs->msr &= ~MSR_VM;
-#endif
 }
 
-#ifdef CONFIG_MMU
 #include <linux/elfcore.h>
 /*
  * Set up a thread for executing a new program
@@ -145,7 +136,6 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
 {
 	return 0; /* MicroBlaze has no separate FPU registers */
 }
-#endif /* CONFIG_MMU */
 
 void arch_cpu_idle(void)
 {

arch/microblaze/kernel/setup.c

@@ -190,12 +190,10 @@ static int microblaze_debugfs_init(void)
 }
 arch_initcall(microblaze_debugfs_init);
 
-# ifdef CONFIG_MMU
 static int __init debugfs_tlb(void)
 {
 	debugfs_create_u32("tlb_skip", S_IRUGO, of_debugfs_root, &tlb_skip);
 	return 0;
 }
 device_initcall(debugfs_tlb);
-# endif
 #endif

arch/microblaze/kernel/signal.c

@@ -157,10 +157,8 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 	struct rt_sigframe __user *frame;
 	int err = 0, sig = ksig->sig;
 	unsigned long address = 0;
-#ifdef CONFIG_MMU
 	pmd_t *pmdp;
 	pte_t *ptep;
-#endif
 
 	frame = get_sigframe(ksig, regs, sizeof(*frame));
 
@@ -192,7 +190,6 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 	regs->r15 = ((unsigned long)frame->tramp)-8;
 
 	address = ((unsigned long)frame->tramp);
-#ifdef CONFIG_MMU
 	pmdp = pmd_off(current->mm, address);
 
 	preempt_disable();
@@ -208,10 +205,6 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 	}
 	pte_unmap(ptep);
 	preempt_enable();
-#else
-	flush_icache_range(address, address + 8);
-	flush_dcache_range(address, address + 8);
-#endif
 	if (err)
 		return -EFAULT;
 

arch/microblaze/kernel/unwind.c

@@ -161,22 +161,12 @@ static void microblaze_unwind_inner(struct task_struct *task,
  * unwind_trap - Unwind through a system trap, that stored previous state
  *		 on the stack.
  */
-#ifdef CONFIG_MMU
 static inline void unwind_trap(struct task_struct *task, unsigned long pc,
 				unsigned long fp, struct stack_trace *trace,
 				const char *loglvl)
 {
 	/* To be implemented */
 }
-#else
-static inline void unwind_trap(struct task_struct *task, unsigned long pc,
-				unsigned long fp, struct stack_trace *trace,
-				const char *loglvl)
-{
-	const struct pt_regs *regs = (const struct pt_regs *) fp;
-	microblaze_unwind_inner(task, regs->pc, regs->r1, regs->r15, trace, loglvl);
-}
-#endif
 
 /**
  * microblaze_unwind_inner - Unwind the stack from the specified point
@@ -215,16 +205,7 @@ static void microblaze_unwind_inner(struct task_struct *task,
 			 * HW exception handler doesn't save all registers,
 			 * so we open-code a special case of unwind_trap()
 			 */
-#ifndef CONFIG_MMU
-			const struct pt_regs *regs =
-				(const struct pt_regs *) fp;
-#endif
 			printk("%sHW EXCEPTION\n", loglvl);
-#ifndef CONFIG_MMU
-			microblaze_unwind_inner(task, regs->r17 - 4,
-						fp + EX_HANDLER_STACK_SIZ,
-						regs->r15, trace, loglvl);
-#endif
 			return;
 		}
 

arch/microblaze/mm/Makefile

@@ -5,5 +5,5 @@
 
 obj-y := consistent.o init.o
 
-obj-$(CONFIG_MMU) += pgtable.o mmu_context.o fault.o
+obj-y += pgtable.o mmu_context.o fault.o
 obj-$(CONFIG_HIGHMEM) += highmem.o

arch/microblaze/mm/consistent.c

@@ -21,32 +21,3 @@ void arch_dma_prep_coherent(struct page *page, size_t size)
 
 	flush_dcache_range(paddr, paddr + size);
 }
-
-#ifndef CONFIG_MMU
-/*
- * Consistent memory allocators. Used for DMA devices that want to share
- * uncached memory with the processor core.  My crufty no-MMU approach is
- * simple.  In the HW platform we can optionally mirror the DDR up above the
- * processor cacheable region.  So, memory accessed in this mirror region will
- * not be cached.  It's alloced from the same pool as normal memory, but the
- * handle we return is shifted up into the uncached region.  This will no doubt
- * cause big problems if memory allocated here is not also freed properly. -- JW
- *
- * I have to use dcache values because I can't relate on ram size:
- */
-#ifdef CONFIG_XILINX_UNCACHED_SHADOW
-#define UNCACHED_SHADOW_MASK (cpuinfo.dcache_high - cpuinfo.dcache_base + 1)
-#else
-#define UNCACHED_SHADOW_MASK 0
-#endif /* CONFIG_XILINX_UNCACHED_SHADOW */
-
-void *arch_dma_set_uncached(void *ptr, size_t size)
-{
-	unsigned long addr = (unsigned long)ptr;
-
-	addr |= UNCACHED_SHADOW_MASK;
-	if (addr > cpuinfo.dcache_base && addr < cpuinfo.dcache_high)
-		pr_warn("ERROR: Your cache coherent area is CACHED!!!\n");
-	return (void *)addr;
-}
-#endif /* CONFIG_MMU */

arch/microblaze/mm/init.c

@@ -29,11 +29,6 @@
 /* Use for MMU and noMMU because of PCI generic code */
 int mem_init_done;
 
-#ifndef CONFIG_MMU
-unsigned int __page_offset;
-EXPORT_SYMBOL(__page_offset);
-#endif /* CONFIG_MMU */
-
 char *klimit = _end;
 
 /*
@@ -82,13 +77,11 @@ static void highmem_setup(void)
 static void __init paging_init(void)
 {
 	unsigned long zones_size[MAX_NR_ZONES];
-#ifdef CONFIG_MMU
 	int idx;
 
 	/* Setup fixmaps */
 	for (idx = 0; idx < __end_of_fixed_addresses; idx++)
 		clear_fixmap(idx);
-#endif
 
 	/* Clean every zones */
 	memset(zones_size, 0, sizeof(zones_size));
@@ -108,40 +101,6 @@ static void __init paging_init(void)
 
 void __init setup_memory(void)
 {
-#ifndef CONFIG_MMU
-	u32 kernel_align_start, kernel_align_size;
-	phys_addr_t start, end;
-	u64 i;
-
-	/* Find main memory where is the kernel */
-	for_each_mem_range(i, &start, &end) {
-		memory_start = start;
-		lowmem_size = end - start;
-		if ((memory_start <= (u32)_text) &&
-			((u32)_text <= (memory_start + lowmem_size - 1))) {
-			memory_size = lowmem_size;
-			PAGE_OFFSET = memory_start;
-			pr_info("%s: Main mem: 0x%x, size 0x%08x\n",
-				__func__, (u32) memory_start,
-					(u32) memory_size);
-			break;
-		}
-	}
-
-	if (!memory_start || !memory_size) {
-		panic("%s: Missing memory setting 0x%08x, size=0x%08x\n",
-			__func__, (u32) memory_start, (u32) memory_size);
-	}
-
-	/* reservation of region where is the kernel */
-	kernel_align_start = PAGE_DOWN((u32)_text);
-	/* ALIGN can be remove because _end in vmlinux.lds.S is align */
-	kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start;
-	pr_info("%s: kernel addr:0x%08x-0x%08x size=0x%08x\n",
-		__func__, kernel_align_start, kernel_align_start
-			+ kernel_align_size, kernel_align_size);
-	memblock_reserve(kernel_align_start, kernel_align_size);
-#endif
 	/*
 	 * Kernel:
 	 * start: base phys address of kernel - page align
@@ -181,12 +140,6 @@ void __init mem_init(void)
 	mem_init_done = 1;
 }
 
-#ifndef CONFIG_MMU
-int page_is_ram(unsigned long pfn)
-{
-	return __range_ok(pfn, 0);
-}
-#else
 int page_is_ram(unsigned long pfn)
 {
 	return pfn < max_low_pfn;
@@ -330,8 +283,6 @@ void __init *early_get_page(void)
 				NUMA_NO_NODE);
 }
 
-#endif /* CONFIG_MMU */
-
 void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
 {
 	void *p;

arch/microblaze/pci/pci-common.c

@@ -325,12 +325,10 @@ int pci_mmap_legacy_page_range(struct pci_bus *bus,
 		 * memory, effectively behaving just like /dev/zero
 		 */
 		if ((offset + size) > hose->isa_mem_size) {
-#ifdef CONFIG_MMU
 			pr_debug("Process %s (pid:%d) mapped non-existing PCI",
 				current->comm, current->pid);
 			pr_debug("legacy memory for 0%04x:%02x\n",
 				pci_domain_nr(bus), bus->number);
-#endif
 			if (vma->vm_flags & VM_SHARED)
 				return shmem_zero_setup(vma);
 			return 0;