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, 377 deletions

diff --git a/arch/nds32/include/asm/pgtable.h b/arch/nds32/include/asm/pgtable.h
deleted file mode 100644
index 419f984eef70..000000000000
--- a/arch/nds32/include/asm/pgtable.h
+++ /dev/null
@@ -1,377 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-// Copyright (C) 2005-2017 Andes Technology Corporation
-
-#ifndef _ASMNDS32_PGTABLE_H
-#define _ASMNDS32_PGTABLE_H
-
-#include <asm-generic/pgtable-nopmd.h>
-#include <linux/sizes.h>
-
-#include <asm/memory.h>
-#include <asm/nds32.h>
-#ifndef __ASSEMBLY__
-#include <asm/fixmap.h>
-#include <nds32_intrinsic.h>
-#endif
-
-#ifdef CONFIG_ANDES_PAGE_SIZE_4KB
-#define PGDIR_SHIFT      22
-#define PTRS_PER_PGD     1024
-#define PTRS_PER_PTE     1024
-#endif
-
-#ifdef CONFIG_ANDES_PAGE_SIZE_8KB
-#define PGDIR_SHIFT      24
-#define PTRS_PER_PGD     256
-#define PTRS_PER_PTE     2048
-#endif
-
-#ifndef __ASSEMBLY__
-extern void __pte_error(const char *file, int line, unsigned long val);
-extern void __pgd_error(const char *file, int line, unsigned long val);
-
-#define pte_ERROR(pte)		__pte_error(__FILE__, __LINE__, pte_val(pte))
-#define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
-#endif /* !__ASSEMBLY__ */
-
-#define PMD_SIZE		(1UL << PMD_SHIFT)
-#define PMD_MASK		(~(PMD_SIZE-1))
-#define PGDIR_SIZE		(1UL << PGDIR_SHIFT)
-#define PGDIR_MASK		(~(PGDIR_SIZE-1))
-
-/*
- * This is the lowest virtual address we can permit any user space
- * mapping to be mapped at.  This is particularly important for
- * non-high vector CPUs.
- */
-#define FIRST_USER_ADDRESS	0x8000
-
-#ifdef CONFIG_HIGHMEM
-#define CONSISTENT_BASE		((PKMAP_BASE) - (SZ_2M))
-#define CONSISTENT_END		(PKMAP_BASE)
-#else
-#define CONSISTENT_BASE		(FIXADDR_START - SZ_2M)
-#define CONSISTENT_END		(FIXADDR_START)
-#endif
-#define CONSISTENT_OFFSET(x)	(((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT)
-
-#ifdef CONFIG_HIGHMEM
-#ifndef __ASSEMBLY__
-#include <asm/highmem.h>
-#endif
-#endif
-
-#define VMALLOC_RESERVE 	SZ_128M
-#define VMALLOC_END		(CONSISTENT_BASE - PAGE_SIZE)
-#define VMALLOC_START		((VMALLOC_END) - VMALLOC_RESERVE)
-#define VMALLOC_VMADDR(x)	((unsigned long)(x))
-#define MAXMEM			__pa(VMALLOC_START)
-#define MAXMEM_PFN		PFN_DOWN(MAXMEM)
-
-#define FIRST_USER_PGD_NR	0
-#define USER_PTRS_PER_PGD	((TASK_SIZE/PGDIR_SIZE) + FIRST_USER_PGD_NR)
-
-/* L2 PTE */
-#define _PAGE_V			(1UL << 0)
-
-#define _PAGE_M_XKRW            (0UL << 1)
-#define _PAGE_M_UR_KR		(1UL << 1)
-#define _PAGE_M_UR_KRW		(2UL << 1)
-#define _PAGE_M_URW_KRW		(3UL << 1)
-#define _PAGE_M_KR		(5UL << 1)
-#define _PAGE_M_KRW		(7UL << 1)
-
-#define _PAGE_D			(1UL << 4)
-#define _PAGE_E			(1UL << 5)
-#define _PAGE_A			(1UL << 6)
-#define _PAGE_G			(1UL << 7)
-
-#define _PAGE_C_DEV		(0UL << 8)
-#define _PAGE_C_DEV_WB		(1UL << 8)
-#define _PAGE_C_MEM		(2UL << 8)
-#define _PAGE_C_MEM_SHRD_WB	(4UL << 8)
-#define _PAGE_C_MEM_SHRD_WT	(5UL << 8)
-#define _PAGE_C_MEM_WB		(6UL << 8)
-#define _PAGE_C_MEM_WT		(7UL << 8)
-
-#define _PAGE_L			(1UL << 11)
-
-#define _HAVE_PAGE_L		(_PAGE_L)
-#define _PAGE_FILE		(1UL << 1)
-#define _PAGE_YOUNG		0
-#define _PAGE_M_MASK		_PAGE_M_KRW
-#define _PAGE_C_MASK		_PAGE_C_MEM_WT
-
-#ifdef CONFIG_SMP
-#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
-#define _PAGE_CACHE_SHRD	_PAGE_C_MEM_SHRD_WT
-#else
-#define _PAGE_CACHE_SHRD	_PAGE_C_MEM_SHRD_WB
-#endif
-#else
-#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
-#define _PAGE_CACHE_SHRD	_PAGE_C_MEM_WT
-#else
-#define _PAGE_CACHE_SHRD	_PAGE_C_MEM_WB
-#endif
-#endif
-
-#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
-#define _PAGE_CACHE		_PAGE_C_MEM_WT
-#else
-#define _PAGE_CACHE		_PAGE_C_MEM_WB
-#endif
-
-#define _PAGE_IOREMAP \
-	(_PAGE_V | _PAGE_M_KRW | _PAGE_D | _PAGE_G | _PAGE_C_DEV)
-
-/*
- * + Level 1 descriptor (PMD)
- */
-#define PMD_TYPE_TABLE		0
-
-#ifndef __ASSEMBLY__
-
-#define _PAGE_USER_TABLE     PMD_TYPE_TABLE
-#define _PAGE_KERNEL_TABLE   PMD_TYPE_TABLE
-
-#define PAGE_EXEC	__pgprot(_PAGE_V | _PAGE_M_XKRW | _PAGE_E)
-#define PAGE_NONE	__pgprot(_PAGE_V | _PAGE_M_KRW | _PAGE_A)
-#define PAGE_READ	__pgprot(_PAGE_V | _PAGE_M_UR_KR)
-#define PAGE_RDWR	__pgprot(_PAGE_V | _PAGE_M_URW_KRW | _PAGE_D)
-#define PAGE_COPY	__pgprot(_PAGE_V | _PAGE_M_UR_KR)
-
-#define PAGE_UXKRWX_V1	__pgprot(_PAGE_V | _PAGE_M_KRW | _PAGE_D | _PAGE_E | _PAGE_G | _PAGE_CACHE_SHRD)
-#define PAGE_UXKRWX_V2	__pgprot(_PAGE_V | _PAGE_M_XKRW | _PAGE_D | _PAGE_E | _PAGE_G | _PAGE_CACHE_SHRD)
-#define PAGE_URXKRWX_V2	__pgprot(_PAGE_V | _PAGE_M_UR_KRW | _PAGE_D | _PAGE_E | _PAGE_G | _PAGE_CACHE_SHRD)
-#define PAGE_CACHE_L1	__pgprot(_HAVE_PAGE_L | _PAGE_V | _PAGE_M_KRW | _PAGE_D | _PAGE_E | _PAGE_G | _PAGE_CACHE)
-#define PAGE_MEMORY	__pgprot(_HAVE_PAGE_L | _PAGE_V | _PAGE_M_KRW | _PAGE_D | _PAGE_E | _PAGE_G | _PAGE_CACHE_SHRD)
-#define PAGE_KERNEL	__pgprot(_PAGE_V | _PAGE_M_KRW | _PAGE_D | _PAGE_E | _PAGE_G | _PAGE_CACHE_SHRD)
-#define PAGE_SHARED	__pgprot(_PAGE_V | _PAGE_M_URW_KRW | _PAGE_D | _PAGE_CACHE_SHRD)
-#define PAGE_DEVICE    __pgprot(_PAGE_V | _PAGE_M_KRW | _PAGE_D | _PAGE_G | _PAGE_C_DEV)
-#endif /* __ASSEMBLY__ */
-
-/*         xwr */
-#define __P000  (PAGE_NONE | _PAGE_CACHE_SHRD)
-#define __P001  (PAGE_READ | _PAGE_CACHE_SHRD)
-#define __P010  (PAGE_COPY | _PAGE_CACHE_SHRD)
-#define __P011  (PAGE_COPY | _PAGE_CACHE_SHRD)
-#define __P100  (PAGE_EXEC | _PAGE_CACHE_SHRD)
-#define __P101  (PAGE_READ | _PAGE_E | _PAGE_CACHE_SHRD)
-#define __P110  (PAGE_COPY | _PAGE_E | _PAGE_CACHE_SHRD)
-#define __P111  (PAGE_COPY | _PAGE_E | _PAGE_CACHE_SHRD)
-
-#define __S000  (PAGE_NONE | _PAGE_CACHE_SHRD)
-#define __S001  (PAGE_READ | _PAGE_CACHE_SHRD)
-#define __S010  (PAGE_RDWR | _PAGE_CACHE_SHRD)
-#define __S011  (PAGE_RDWR | _PAGE_CACHE_SHRD)
-#define __S100  (PAGE_EXEC | _PAGE_CACHE_SHRD)
-#define __S101  (PAGE_READ | _PAGE_E | _PAGE_CACHE_SHRD)
-#define __S110  (PAGE_RDWR | _PAGE_E | _PAGE_CACHE_SHRD)
-#define __S111  (PAGE_RDWR | _PAGE_E | _PAGE_CACHE_SHRD)
-
-#ifndef __ASSEMBLY__
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-extern struct page *empty_zero_page;
-extern void paging_init(void);
-#define ZERO_PAGE(vaddr)	(empty_zero_page)
-
-#define pte_pfn(pte)		(pte_val(pte) >> PAGE_SHIFT)
-#define pfn_pte(pfn,prot)	(__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot)))
-
-#define pte_none(pte)	        !(pte_val(pte))
-#define pte_clear(mm,addr,ptep)	set_pte_at((mm),(addr),(ptep), __pte(0))
-#define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
-
-static unsigned long pmd_page_vaddr(pmd_t pmd)
-{
-	return ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK));
-}
-
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
-/*
- * Set a level 1 translation table entry, and clean it out of
- * any caches such that the MMUs can load it correctly.
- */
-static inline void set_pmd(pmd_t * pmdp, pmd_t pmd)
-{
-
-	*pmdp = pmd;
-#if !defined(CONFIG_CPU_DCACHE_DISABLE) && !defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
-	__asm__ volatile ("\n\tcctl %0, L1D_VA_WB"::"r" (pmdp):"memory");
-	__nds32__msync_all();
-	__nds32__dsb();
-#endif
-}
-
-/*
- * Set a PTE and flush it out
- */
-static inline void set_pte(pte_t * ptep, pte_t pte)
-{
-
-	*ptep = pte;
-#if !defined(CONFIG_CPU_DCACHE_DISABLE) && !defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
-	__asm__ volatile ("\n\tcctl %0, L1D_VA_WB"::"r" (ptep):"memory");
-	__nds32__msync_all();
-	__nds32__dsb();
-#endif
-}
-
-/*
- * The following only work if pte_present() is true.
- * Undefined behaviour if not..
- */
-
-/*
- * pte_write: 	     this page is writeable for user mode
- * pte_read:         this page is readable for user mode
- * pte_kernel_write: this page is writeable for kernel mode
- *
- * We don't have pte_kernel_read because kernel always can read.
- *
- * */
-
-#define pte_present(pte)        (pte_val(pte) & _PAGE_V)
-#define pte_write(pte)          ((pte_val(pte) & _PAGE_M_MASK) == _PAGE_M_URW_KRW)
-#define pte_read(pte)		(((pte_val(pte) & _PAGE_M_MASK) == _PAGE_M_UR_KR) || \
-				((pte_val(pte) & _PAGE_M_MASK) == _PAGE_M_UR_KRW) || \
-				((pte_val(pte) & _PAGE_M_MASK) == _PAGE_M_URW_KRW))
-#define pte_kernel_write(pte)   (((pte_val(pte) & _PAGE_M_MASK) == _PAGE_M_URW_KRW) || \
-				((pte_val(pte) & _PAGE_M_MASK) == _PAGE_M_UR_KRW) || \
-				((pte_val(pte) & _PAGE_M_MASK) == _PAGE_M_KRW) || \
-				(((pte_val(pte) & _PAGE_M_MASK) == _PAGE_M_XKRW) && pte_exec(pte)))
-#define pte_exec(pte)		(pte_val(pte) & _PAGE_E)
-#define pte_dirty(pte)		(pte_val(pte) & _PAGE_D)
-#define pte_young(pte)		(pte_val(pte) & _PAGE_YOUNG)
-
-/*
- * The following only works if pte_present() is not true.
- */
-#define pte_file(pte)		(pte_val(pte) & _PAGE_FILE)
-#define pte_to_pgoff(x)		(pte_val(x) >> 2)
-#define pgoff_to_pte(x)		__pte(((x) << 2) | _PAGE_FILE)
-
-#define PTE_FILE_MAX_BITS	29
-
-#define PTE_BIT_FUNC(fn,op) \
-static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
-
-static inline pte_t pte_wrprotect(pte_t pte)
-{
-	pte_val(pte) = pte_val(pte) & ~_PAGE_M_MASK;
-	pte_val(pte) = pte_val(pte) | _PAGE_M_UR_KR;
-	return pte;
-}
-
-static inline pte_t pte_mkwrite(pte_t pte)
-{
-	pte_val(pte) = pte_val(pte) & ~_PAGE_M_MASK;
-	pte_val(pte) = pte_val(pte) | _PAGE_M_URW_KRW;
-	return pte;
-}
-
-PTE_BIT_FUNC(exprotect, &=~_PAGE_E);
-PTE_BIT_FUNC(mkexec, |=_PAGE_E);
-PTE_BIT_FUNC(mkclean, &=~_PAGE_D);
-PTE_BIT_FUNC(mkdirty, |=_PAGE_D);
-PTE_BIT_FUNC(mkold, &=~_PAGE_YOUNG);
-PTE_BIT_FUNC(mkyoung, |=_PAGE_YOUNG);
-
-/*
- * Mark the prot value as uncacheable and unbufferable.
- */
-#define pgprot_noncached(prot)	   __pgprot((pgprot_val(prot)&~_PAGE_C_MASK) | _PAGE_C_DEV)
-#define pgprot_writecombine(prot)  __pgprot((pgprot_val(prot)&~_PAGE_C_MASK) | _PAGE_C_DEV_WB)
-
-#define pmd_none(pmd)         (pmd_val(pmd)&0x1)
-#define pmd_present(pmd)      (!pmd_none(pmd))
-#define	pmd_bad(pmd)	      pmd_none(pmd)
-
-#define copy_pmd(pmdpd,pmdps)	set_pmd((pmdpd), *(pmdps))
-#define pmd_clear(pmdp)		set_pmd((pmdp), __pmd(1))
-
-static inline pmd_t __mk_pmd(pte_t * ptep, unsigned long prot)
-{
-	unsigned long ptr = (unsigned long)ptep;
-	pmd_t pmd;
-
-	/*
-	 * The pmd must be loaded with the physical
-	 * address of the PTE table
-	 */
-
-	pmd_val(pmd) = __virt_to_phys(ptr) | prot;
-	return pmd;
-}
-
-#define pmd_page(pmd)        virt_to_page(__va(pmd_val(pmd)))
-
-/*
- * Permanent address of a page. We never have highmem, so this is trivial.
- */
-#define pages_to_mb(x)       ((x) >> (20 - PAGE_SHIFT))
-
-/*
- * Conversion functions: convert a page and protection to a page entry,
- * and a page entry and page directory to the page they refer to.
- */
-#define mk_pte(page,prot)	pfn_pte(page_to_pfn(page),prot)
-
-/*
- * The "pgd_xxx()" functions here are trivial for a folded two-level
- * setup: the pgd is never bad, and a pmd always exists (as it's folded
- * into the pgd entry)
- */
-#define pgd_none(pgd)		(0)
-#define pgd_bad(pgd)		(0)
-#define pgd_present(pgd)  	(1)
-#define pgd_clear(pgdp)		do { } while (0)
-
-#define page_pte_prot(page,prot)     	mk_pte(page, prot)
-#define page_pte(page)		        mk_pte(page, __pgprot(0))
-/*
- *     L1PTE = $mr1 + ((virt >> PMD_SHIFT) << 2);
- *     L2PTE = (((virt >> PAGE_SHIFT) & (PTRS_PER_PTE -1 )) << 2);
- *     PPN = (phys & 0xfffff000);
- *
-*/
-
-static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
-{
-	const unsigned long mask = 0xfff;
-	pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
-	return pte;
-}
-
-extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
-
-/* Encode and decode a swap entry.
- *
- * We support up to 32GB of swap on 4k machines
- */
-#define __swp_type(x)	 	     (((x).val >> 2) & 0x7f)
-#define __swp_offset(x)	   	     ((x).val >> 9)
-#define __swp_entry(type,offset)     ((swp_entry_t) { ((type) << 2) | ((offset) << 9) })
-#define __pte_to_swp_entry(pte)	     ((swp_entry_t) { pte_val(pte) })
-#define __swp_entry_to_pte(swp)	     ((pte_t) { (swp).val })
-
-/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
-#define kern_addr_valid(addr)	(1)
-
-/*
- * We provide our own arch_get_unmapped_area to cope with VIPT caches.
- */
-#define HAVE_ARCH_UNMAPPED_AREA
-
-/*
- * remap a physical address `phys' of size `size' with page protection `prot'
- * into virtual address `from'
- */
-
-#endif /* !__ASSEMBLY__ */
-
-#endif /* _ASMNDS32_PGTABLE_H */