csky: optimize memcpy_{from,to}io() and memset_io()

Optimize memcpy_{from,to}io() and memset_io() by transferring in
64 bit as much as possible with minimized barrier usage. This
simplest optimization brings faster throughput compare to current
byte-by-byte read and write with barrier in the loop. Code's
skeleton is taken from the powerpc & arm64.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>

csky: Fix versioncheck warnings

$make versioncheck

arch/csky/include/asm/io.h: 8 linux/version.h not needed.
arch/csky/kernel/process.c: 5 linux/version.h not needed.
arch/csky/mm/dma-mapping.c: 12 linux/version.h not needed.

comments from Randy:

The patch makes sense but these are not compile warnings.
They come from scripts/checkversion.pl, which can be called
by 'make versioncheck', so I suppose that something in your
build system is running 'make versioncheck'.

Signed-off-by: Deyan Wang <wonder_rock@126.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>

csky: Fixup compile error

: error: C++ style comments are not allowed in ISO C90
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
^
error: (this will be reported only once per input file)

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

mm: introduce include/linux/pgtable.h

The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.

Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

csky: use generic ioremap

Use the generic ioremap_prot and iounmap helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Guo Ren <guoren@kernel.org>

csky: remove ioremap_cache

No driver that can be used on csky uses ioremap_cache, and this
interface has been deprecated in favor of memremap.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Guo Ren <guoren@kernel.org>

arch: rely on asm-generic/io.h for default ioremap_* definitions

Various architectures that use asm-generic/io.h still defined their
own default versions of ioremap_nocache, ioremap_wt and ioremap_wc
that point back to plain ioremap directly or indirectly. Remove these
definitions and rely on asm-generic/io.h instead. For this to work
the backup ioremap_* defintions needs to be changed to purely cpp
macros instea of inlines to cover for architectures like openrisc
that only define ioremap after including <asm-generic/io.h>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Palmer Dabbelt <palmer@dabbelt.com>

csky: Fixup ioremap function losing

Implement the following apis to meet usage in different scenarios.

- ioremap (NonCache + StrongOrder)
- ioremap_nocache (NonCache + StrongOrder)
- ioremap_wc (NonCache + WeakOrder )
- ioremap_cache ( Cache + WeakOrder )

Also change flag VM_ALLOC to VM_IOREMAP in get_vm_area_caller.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@infradead.org>

csky: fixup CACHEV1 store instruction fast retire

For I/O access, 810/807 store instruction fast retire will cause wrong
primitive. For example:

stw (clear interrupt source)
stw (unmask interrupt controller)
enable interrupt

stw is fast retire instruction. When PC is run at enable interrupt
stage, the clear interrupt source hasn't finished. It will cause another
wrong irq-enter.

So use mb() to prevent above.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Lu Baoquan <lu.baoquan@intellif.com>

csky: Cache and TLB routines

This patch adds cache and tlb sync codes for abiv1 & abiv2.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>