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>

1 files changed, 0 insertions, 282 deletions

diff --git a/arch/nds32/include/asm/uaccess.h b/arch/nds32/include/asm/uaccess.h
deleted file mode 100644
index 377548d4451a..000000000000
--- a/arch/nds32/include/asm/uaccess.h
+++ /dev/null
@@ -1,282 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#ifndef _ASMANDES_UACCESS_H
-#define _ASMANDES_UACCESS_H
-
-/*
- * User space memory access functions
- */
-#include <linux/sched.h>
-#include <asm/errno.h>
-#include <asm/memory.h>
-#include <asm/types.h>
-#include <asm-generic/access_ok.h>
-
-#define __asmeq(x, y)  ".ifnc " x "," y " ; .err ; .endif\n\t"
-
-/*
- * The exception table consists of pairs of addresses: the first is the
- * address of an instruction that is allowed to fault, and the second is
- * the address at which the program should continue.  No registers are
- * modified, so it is entirely up to the continuation code to figure out
- * what to do.
- *
- * All the routines below use bits of fixup code that are out of line
- * with the main instruction path.  This means when everything is well,
- * we don't even have to jump over them.  Further, they do not intrude
- * on our cache or tlb entries.
- */
-
-struct exception_table_entry {
-	unsigned long insn, fixup;
-};
-
-extern int fixup_exception(struct pt_regs *regs);
-
-/*
- * Single-value transfer routines.  They automatically use the right
- * size if we just have the right pointer type.  Note that the functions
- * which read from user space (*get_*) need to take care not to leak
- * kernel data even if the calling code is buggy and fails to check
- * the return value.  This means zeroing out the destination variable
- * or buffer on error.  Normally this is done out of line by the
- * fixup code, but there are a few places where it intrudes on the
- * main code path.  When we only write to user space, there is no
- * problem.
- *
- * The "__xxx" versions of the user access functions do not verify the
- * address space - it must have been done previously with a separate
- * "access_ok()" call.
- *
- * The "xxx_error" versions set the third argument to EFAULT if an
- * error occurs, and leave it unchanged on success.  Note that these
- * versions are void (ie, don't return a value as such).
- */
-
-#define get_user(x, ptr)						\
-({									\
-	long __gu_err = 0;						\
-	__get_user_check((x), (ptr), __gu_err);				\
-	__gu_err;							\
-})
-
-#define __get_user_error(x, ptr, err)					\
-({									\
-	__get_user_check((x), (ptr), (err));				\
-	(void)0;							\
-})
-
-#define __get_user(x, ptr)						\
-({									\
-	long __gu_err = 0;						\
-	const __typeof__(*(ptr)) __user *__p = (ptr);			\
-	__get_user_err((x), __p, (__gu_err));				\
-	__gu_err;							\
-})
-
-#define __get_user_check(x, ptr, err)					\
-({									\
-	const __typeof__(*(ptr)) __user *__p = (ptr);			\
-	might_fault();							\
-	if (access_ok(__p, sizeof(*__p))) {		\
-		__get_user_err((x), __p, (err));			\
-	} else {							\
-		(x) = 0; (err) = -EFAULT;				\
-	}								\
-})
-
-#define __get_user_err(x, ptr, err)					\
-do {									\
-	unsigned long __gu_val;						\
-	__chk_user_ptr(ptr);						\
-	switch (sizeof(*(ptr))) {					\
-	case 1:								\
-		__get_user_asm("lbi", __gu_val, (ptr), (err));		\
-		break;							\
-	case 2:								\
-		__get_user_asm("lhi", __gu_val, (ptr), (err));		\
-		break;							\
-	case 4:								\
-		__get_user_asm("lwi", __gu_val, (ptr), (err));		\
-		break;							\
-	case 8:								\
-		__get_user_asm_dword(__gu_val, (ptr), (err));		\
-		break;							\
-	default:							\
-		BUILD_BUG(); 						\
-		break;							\
-	}								\
-	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
-} while (0)
-
-#define __get_user_asm(inst, x, addr, err)				\
-	__asm__ __volatile__ (						\
-		"1:	"inst"	%1,[%2]\n"				\
-		"2:\n"							\
-		"	.section .fixup,\"ax\"\n"			\
-		"	.align	2\n"					\
-		"3:	move %0, %3\n"					\
-		"	move %1, #0\n"					\
-		"	b	2b\n"					\
-		"	.previous\n"					\
-		"	.section __ex_table,\"a\"\n"			\
-		"	.align	3\n"					\
-		"	.long	1b, 3b\n"				\
-		"	.previous"					\
-		: "+r" (err), "=&r" (x)					\
-		: "r" (addr), "i" (-EFAULT)				\
-		: "cc")
-
-#ifdef __NDS32_EB__
-#define __gu_reg_oper0 "%H1"
-#define __gu_reg_oper1 "%L1"
-#else
-#define __gu_reg_oper0 "%L1"
-#define __gu_reg_oper1 "%H1"
-#endif
-
-#define __get_user_asm_dword(x, addr, err) 				\
-	__asm__ __volatile__ (						\
-		"\n1:\tlwi " __gu_reg_oper0 ",[%2]\n"			\
-		"\n2:\tlwi " __gu_reg_oper1 ",[%2+4]\n"			\
-		"3:\n"							\
-		"	.section .fixup,\"ax\"\n"			\
-		"	.align	2\n"					\
-		"4:	move	%0, %3\n"				\
-		"	b	3b\n"					\
-		"	.previous\n"					\
-		"	.section __ex_table,\"a\"\n"			\
-		"	.align	3\n"					\
-		"	.long	1b, 4b\n"				\
-		"	.long	2b, 4b\n"				\
-		"	.previous"					\
-		: "+r"(err), "=&r"(x)					\
-		: "r"(addr), "i"(-EFAULT)				\
-		: "cc")
-
-#define put_user(x, ptr)						\
-({									\
-	long __pu_err = 0;						\
-	__put_user_check((x), (ptr), __pu_err);				\
-	__pu_err;							\
-})
-
-#define __put_user(x, ptr)						\
-({									\
-	long __pu_err = 0;						\
-	__typeof__(*(ptr)) __user *__p = (ptr);				\
-	__put_user_err((x), __p, __pu_err);				\
-	__pu_err;							\
-})
-
-#define __put_user_error(x, ptr, err)					\
-({									\
-	__put_user_err((x), (ptr), (err));				\
-	(void)0;							\
-})
-
-#define __put_user_check(x, ptr, err)					\
-({									\
-	__typeof__(*(ptr)) __user *__p = (ptr);				\
-	might_fault();							\
-	if (access_ok(__p, sizeof(*__p))) {		\
-		__put_user_err((x), __p, (err));			\
-	} else	{							\
-		(err) = -EFAULT;					\
-	}								\
-})
-
-#define __put_user_err(x, ptr, err)					\
-do {									\
-	__typeof__(*(ptr)) __pu_val = (x);				\
-	__chk_user_ptr(ptr);						\
-	switch (sizeof(*(ptr))) {					\
-	case 1:								\
-		__put_user_asm("sbi", __pu_val, (ptr), (err));		\
-		break;							\
-	case 2: 							\
-		__put_user_asm("shi", __pu_val, (ptr), (err));		\
-		break;							\
-	case 4: 							\
-		__put_user_asm("swi", __pu_val, (ptr), (err));		\
-		break;							\
-	case 8:								\
-		__put_user_asm_dword(__pu_val, (ptr), (err));		\
-		break;							\
-	default:							\
-		BUILD_BUG(); 						\
-		break;							\
-	}								\
-} while (0)
-
-#define __put_user_asm(inst, x, addr, err)				\
-	__asm__ __volatile__ (						\
-		"1:	"inst"	%1,[%2]\n"				\
-		"2:\n"							\
-		"	.section .fixup,\"ax\"\n"			\
-		"	.align	2\n"					\
-		"3:	move	%0, %3\n"				\
-		"	b	2b\n"					\
-		"	.previous\n"					\
-		"	.section __ex_table,\"a\"\n"			\
-		"	.align	3\n"					\
-		"	.long	1b, 3b\n"				\
-		"	.previous"					\
-		: "+r" (err)						\
-		: "r" (x), "r" (addr), "i" (-EFAULT)			\
-		: "cc")
-
-#ifdef __NDS32_EB__
-#define __pu_reg_oper0 "%H2"
-#define __pu_reg_oper1 "%L2"
-#else
-#define __pu_reg_oper0 "%L2"
-#define __pu_reg_oper1 "%H2"
-#endif
-
-#define __put_user_asm_dword(x, addr, err) 				\
-	__asm__ __volatile__ (						\
-		"\n1:\tswi " __pu_reg_oper0 ",[%1]\n"			\
-		"\n2:\tswi " __pu_reg_oper1 ",[%1+4]\n"			\
-		"3:\n"							\
-		"	.section .fixup,\"ax\"\n"			\
-		"	.align	2\n"					\
-		"4:	move	%0, %3\n"				\
-		"	b	3b\n"					\
-		"	.previous\n"					\
-		"	.section __ex_table,\"a\"\n"			\
-		"	.align	3\n"					\
-		"	.long	1b, 4b\n"				\
-		"	.long	2b, 4b\n"				\
-		"	.previous"					\
-		: "+r"(err)						\
-		: "r"(addr), "r"(x), "i"(-EFAULT)			\
-		: "cc")
-
-extern unsigned long __arch_clear_user(void __user * addr, unsigned long n);
-extern long strncpy_from_user(char *dest, const char __user * src, long count);
-extern __must_check long strnlen_user(const char __user * str, long n);
-extern unsigned long __arch_copy_from_user(void *to, const void __user * from,
-                                           unsigned long n);
-extern unsigned long __arch_copy_to_user(void __user * to, const void *from,
-                                         unsigned long n);
-
-#define raw_copy_from_user __arch_copy_from_user
-#define raw_copy_to_user __arch_copy_to_user
-
-#define INLINE_COPY_FROM_USER
-#define INLINE_COPY_TO_USER
-static inline unsigned long clear_user(void __user * to, unsigned long n)
-{
-	if (access_ok(to, n))
-		n = __arch_clear_user(to, n);
-	return n;
-}
-
-static inline unsigned long __clear_user(void __user * to, unsigned long n)
-{
-	return __arch_clear_user(to, n);
-}
-
-#endif /* _ASMNDS32_UACCESS_H */