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, 77 deletions

diff --git a/arch/nds32/include/asm/ptrace.h b/arch/nds32/include/asm/ptrace.h
deleted file mode 100644
index 919ee223620c..000000000000
--- a/arch/nds32/include/asm/ptrace.h
+++ /dev/null
@@ -1,77 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#ifndef __ASM_NDS32_PTRACE_H
-#define __ASM_NDS32_PTRACE_H
-
-#include <uapi/asm/ptrace.h>
-
-/*
- * If pt_regs.syscallno == NO_SYSCALL, then the thread is not executing
- * a syscall -- i.e., its most recent entry into the kernel from
- * userspace was not via syscall, or otherwise a tracer cancelled the
- * syscall.
- *
- * This must have the value -1, for ABI compatibility with ptrace etc.
- */
-#define NO_SYSCALL (-1)
-#ifndef __ASSEMBLY__
-#include <linux/types.h>
-
-struct pt_regs {
-	union {
-		struct user_pt_regs user_regs;
-		struct {
-			long uregs[26];
-			long fp;
-			long gp;
-			long lp;
-			long sp;
-			long ipc;
-#if defined(CONFIG_HWZOL)
-			long lb;
-			long le;
-			long lc;
-#else
-			long dummy[3];
-#endif
-			long syscallno;
-		};
-	};
-	long orig_r0;
-	long ir0;
-	long ipsw;
-	long pipsw;
-	long pipc;
-	long pp0;
-	long pp1;
-	long fucop_ctl;
-	long osp;
-};
-
-static inline bool in_syscall(struct pt_regs const *regs)
-{
-	return regs->syscallno != NO_SYSCALL;
-}
-
-static inline void forget_syscall(struct pt_regs *regs)
-{
-	regs->syscallno = NO_SYSCALL;
-}
-static inline unsigned long regs_return_value(struct pt_regs *regs)
-{
-	return regs->uregs[0];
-}
-extern void show_regs(struct pt_regs *);
-/* Avoid circular header include via sched.h */
-struct task_struct;
-
-#define arch_has_single_step()		(1)
-#define user_mode(regs)			(((regs)->ipsw & PSW_mskPOM) == 0)
-#define interrupts_enabled(regs)	(!!((regs)->ipsw & PSW_mskGIE))
-#define user_stack_pointer(regs)	((regs)->sp)
-#define instruction_pointer(regs)	((regs)->ipc)
-#define profile_pc(regs) 		instruction_pointer(regs)
-
-#endif /* __ASSEMBLY__ */
-#endif