nds32: Remove the architecture

The nds32 architecture, also known as AndeStar V3, is a custom 32-bit
RISC target designed by Andes Technologies. Support was added to the
kernel in 2016 as the replacement RISC-V based V5 processors were
already announced, and maintained by (current or former) Andes
employees.

As explained by Alan Kao, new customers are now all using RISC-V,
and all known nds32 users are already on longterm stable kernels
provided by Andes, with no development work going into mainline
support any more.

While the port is still in a reasonably good shape, it only gets
worse over time without active maintainers, so it seems best
to remove it before it becomes unusable. As always, if it turns
out that there are mainline users after all, and they volunteer
to maintain the port in the future, the removal can be reverted.

Link: https://lore.kernel.org/linux-mm/YhdWNLUhk+x9RAzU@yamatobi.andestech.com/
Link: https://lore.kernel.org/lkml/20220302065213.82702-1-alankao@andestech.com/
Link: https://www.andestech.com/en/products-solutions/andestar-architecture/
Signed-off-by: Alan Kao <alankao@andestech.com>
[arnd: rewrite changelog to provide more background]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

9 files changed, 0 insertions, 200 deletions

diff --git a/arch/nds32/include/uapi/asm/Kbuild b/arch/nds32/include/uapi/asm/Kbuild
deleted file mode 100644
index e78470141932..000000000000
--- a/arch/nds32/include/uapi/asm/Kbuild
+++ /dev/null
@@ -1,2 +0,0 @@
-# SPDX-License-Identifier: GPL-2.0
-generic-y += ucontext.h
diff --git a/arch/nds32/include/uapi/asm/auxvec.h b/arch/nds32/include/uapi/asm/auxvec.h
deleted file mode 100644
index bc0b92ab8c15..000000000000
--- a/arch/nds32/include/uapi/asm/auxvec.h
+++ /dev/null
@@ -1,19 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#ifndef __ASM_AUXVEC_H
-#define __ASM_AUXVEC_H
-
-/*
- * This entry gives some information about the FPU initialization
- * performed by the kernel.
- */
-#define AT_FPUCW	18	/* Used FPU control word.  */
-
-
-/* VDSO location */
-#define AT_SYSINFO_EHDR	33
-
-#define AT_VECTOR_SIZE_ARCH 1
-
-#endif
diff --git a/arch/nds32/include/uapi/asm/byteorder.h b/arch/nds32/include/uapi/asm/byteorder.h
deleted file mode 100644
index c264ef12c49c..000000000000
--- a/arch/nds32/include/uapi/asm/byteorder.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#ifndef __NDS32_BYTEORDER_H__
-#define __NDS32_BYTEORDER_H__
-
-#ifdef __NDS32_EB__
-#include <linux/byteorder/big_endian.h>
-#else
-#include <linux/byteorder/little_endian.h>
-#endif
-
-#endif /* __NDS32_BYTEORDER_H__ */
diff --git a/arch/nds32/include/uapi/asm/cachectl.h b/arch/nds32/include/uapi/asm/cachectl.h
deleted file mode 100644
index 31b9b439d819..000000000000
--- a/arch/nds32/include/uapi/asm/cachectl.h
+++ /dev/null
@@ -1,14 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-// Copyright (C) 1994, 1995, 1996 by Ralf Baechle
-// Copyright (C) 2005-2017 Andes Technology Corporation
-#ifndef	_ASM_CACHECTL
-#define	_ASM_CACHECTL
-
-/*
- * Options for cacheflush system call
- */
-#define	ICACHE	0		/* flush instruction cache        */
-#define	DCACHE	1		/* writeback and flush data cache */
-#define	BCACHE	2		/* flush instruction cache + writeback and flush data cache */
-
-#endif /* _ASM_CACHECTL */
diff --git a/arch/nds32/include/uapi/asm/fp_udfiex_crtl.h b/arch/nds32/include/uapi/asm/fp_udfiex_crtl.h
deleted file mode 100644
index f17396db16ec..000000000000
--- a/arch/nds32/include/uapi/asm/fp_udfiex_crtl.h
+++ /dev/null
@@ -1,16 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/* Copyright (C) 2005-2019 Andes Technology Corporation */
-#ifndef	_FP_UDF_IEX_CRTL_H
-#define	_FP_UDF_IEX_CRTL_H
-
-/*
- * The cmd list of sys_fp_udfiex_crtl()
- */
-/* Disable UDF or IEX trap based on the content of parameter act */
-#define DISABLE_UDF_IEX_TRAP	0
-/* Enable UDF or IEX trap based on the content of parameter act */
-#define ENABLE_UDF_IEX_TRAP	1
-/* Get current status of UDF and IEX trap */
-#define GET_UDF_IEX_TRAP	2
-
-#endif /* _FP_UDF_IEX_CRTL_H */
diff --git a/arch/nds32/include/uapi/asm/param.h b/arch/nds32/include/uapi/asm/param.h
deleted file mode 100644
index 48d00328d328..000000000000
--- a/arch/nds32/include/uapi/asm/param.h
+++ /dev/null
@@ -1,11 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#ifndef __ASM_NDS32_PARAM_H
-#define __ASM_NDS32_PARAM_H
-
-#define EXEC_PAGESIZE	8192
-
-#include <asm-generic/param.h>
-
-#endif /* __ASM_NDS32_PARAM_H */
diff --git a/arch/nds32/include/uapi/asm/ptrace.h b/arch/nds32/include/uapi/asm/ptrace.h
deleted file mode 100644
index d76217c7c010..000000000000
--- a/arch/nds32/include/uapi/asm/ptrace.h
+++ /dev/null
@@ -1,25 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#ifndef __UAPI_ASM_NDS32_PTRACE_H
-#define __UAPI_ASM_NDS32_PTRACE_H
-
-#ifndef __ASSEMBLY__
-
-/*
- * User structures for general purpose register.
- */
-struct user_pt_regs {
-	long uregs[26];
-	long fp;
-	long gp;
-	long lp;
-	long sp;
-	long ipc;
-	long lb;
-	long le;
-	long lc;
-	long syscallno;
-};
-#endif
-#endif
diff --git a/arch/nds32/include/uapi/asm/sigcontext.h b/arch/nds32/include/uapi/asm/sigcontext.h
deleted file mode 100644
index 6c1e6648878f..000000000000
--- a/arch/nds32/include/uapi/asm/sigcontext.h
+++ /dev/null
@@ -1,84 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#ifndef _ASMNDS32_SIGCONTEXT_H
-#define _ASMNDS32_SIGCONTEXT_H
-
-/*
- * Signal context structure - contains all info to do with the state
- * before the signal handler was invoked.  Note: only add new entries
- * to the end of the structure.
- */
-struct fpu_struct {
-	unsigned long long fd_regs[32];
-	unsigned long fpcsr;
-	/*
-	 * When CONFIG_SUPPORT_DENORMAL_ARITHMETIC is defined, kernel prevents
-	 * hardware from treating the denormalized output as an underflow case
-	 * and rounding it to a normal number. Hence kernel enables the UDF and
-	 * IEX trap in the fpcsr register to step in the calculation.
-	 * However, the UDF and IEX trap enable bit in $fpcsr also lose
-	 * their use.
-	 *
-	 * UDF_IEX_trap replaces the feature of UDF and IEX trap enable bit in
-	 * $fpcsr to control the trap of underflow and inexact. The bit filed
-	 * of UDF_IEX_trap is the same as $fpcsr, 10th bit is used to enable UDF
-	 * exception trapping and 11th bit is used to enable IEX exception
-	 * trapping.
-	 *
-	 * UDF_IEX_trap is only modified through fp_udfiex_crtl syscall.
-	 * Therefore, UDF_IEX_trap needn't be saved and restored in each
-	 * context switch.
-	 */
-	unsigned long UDF_IEX_trap;
-};
-
-struct zol_struct {
-	unsigned long nds32_lc;	/* $LC */
-	unsigned long nds32_le;	/* $LE */
-	unsigned long nds32_lb;	/* $LB */
-};
-
-struct sigcontext {
-	unsigned long trap_no;
-	unsigned long error_code;
-	unsigned long oldmask;
-	unsigned long nds32_r0;
-	unsigned long nds32_r1;
-	unsigned long nds32_r2;
-	unsigned long nds32_r3;
-	unsigned long nds32_r4;
-	unsigned long nds32_r5;
-	unsigned long nds32_r6;
-	unsigned long nds32_r7;
-	unsigned long nds32_r8;
-	unsigned long nds32_r9;
-	unsigned long nds32_r10;
-	unsigned long nds32_r11;
-	unsigned long nds32_r12;
-	unsigned long nds32_r13;
-	unsigned long nds32_r14;
-	unsigned long nds32_r15;
-	unsigned long nds32_r16;
-	unsigned long nds32_r17;
-	unsigned long nds32_r18;
-	unsigned long nds32_r19;
-	unsigned long nds32_r20;
-	unsigned long nds32_r21;
-	unsigned long nds32_r22;
-	unsigned long nds32_r23;
-	unsigned long nds32_r24;
-	unsigned long nds32_r25;
-	unsigned long nds32_fp;	/* $r28 */
-	unsigned long nds32_gp;	/* $r29 */
-	unsigned long nds32_lp;	/* $r30 */
-	unsigned long nds32_sp;	/* $r31 */
-	unsigned long nds32_ipc;
-	unsigned long fault_address;
-	unsigned long used_math_flag;
-	/* FPU Registers */
-	struct fpu_struct fpu;
-	struct zol_struct zol;
-};
-
-#endif
diff --git a/arch/nds32/include/uapi/asm/unistd.h b/arch/nds32/include/uapi/asm/unistd.h
deleted file mode 100644
index 410795e280fe..000000000000
--- a/arch/nds32/include/uapi/asm/unistd.h
+++ /dev/null
@@ -1,16 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#define __ARCH_WANT_STAT64
-#define __ARCH_WANT_SYNC_FILE_RANGE2
-#define __ARCH_WANT_SET_GET_RLIMIT
-#define __ARCH_WANT_TIME32_SYSCALLS
-
-/* Use the standard ABI for syscalls */
-#include <asm-generic/unistd.h>
-
-/* Additional NDS32 specific syscalls. */
-#define __NR_cacheflush		(__NR_arch_specific_syscall)
-#define __NR_fp_udfiex_crtl	(__NR_arch_specific_syscall + 1)
-__SYSCALL(__NR_cacheflush, sys_cacheflush)
-__SYSCALL(__NR_fp_udfiex_crtl, sys_fp_udfiex_crtl)