microblaze: use generic strncpy/strnlen from_user

Remove the microblaze implemenation of strncpy/strnlen and instead use
the generic versions. The microblaze version is fairly slow because it
always does byte accesses even for aligned data, and it lacks a checks
for user_addr_max().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

microblaze: Fix a typo

s/storign/storing/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Link: https://lore.kernel.org/r/20210319045323.21241-1-unixbhaskar@gmail.com
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

microblaze: Fix strncpy_from_user macro

Problem happens when len in strncpy_from_user is setup
and passing string has len-1 chars + \0 terminated
character. In this case was returned incorrect length
of the string.
It should always retunrs the length of the string
(not including the trailing NULL).

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

microblaze: Fix stack usage in PAGE_SIZE copy_tofrom_user

If access to user space failed we need to reconstruct
stack pointer and restore all register.

This patch fixed problem introduces by:
"microblaze: Add loop unrolling for PAGE in copy_tofrom_user"
(sha1: ebe211254bfa6295f4ab0b33c7c881bdfabbab60)

Signed-off-by: Michal Simek <monstr@monstr.eu>

microblaze: Use delay slot in __strnlen_user, __strncpy_user

Use delay slot to speedup if maxlen is zero.

Signed-off-by: Michal Simek <monstr@monstr.eu>

microblaze: Add loop unrolling for PAGE in copy_tofrom_user

Increase performance by loop unrolling.

Signed-off-by: Michal Simek <monstr@monstr.eu>

microblaze: Simplify logic for unaligned byte copying

Save jump instruction for unaligned byte copying.

Signed-off-by: Michal Simek <monstr@monstr.eu>

microblaze: Change label names - copy_tofrom_user

Change label name to be prepared for loop unrolling.

Signed-off-by: Michal Simek <monstr@monstr.eu>

microblaze: Separate fixup section definition

Move fixups below appropriate code.

Signed-off-by: Michal Simek <monstr@monstr.eu>

microblaze: Change label name in copy_tofrom_user

Use label 0: for zero length copying and fixups.

Signed-off-by: Michal Simek <monstr@monstr.eu>

microblaze: Support word copying in copy_tofrom_user

Word copying is used only for aligned addresses.
Here is space for improving to use any better copying technique.
Look at memcpy implementation.

Signed-off-by: Michal Simek <monstr@monstr.eu>

microblaze: Add .type and .size to ASM functions

Cachegrind analysis need this fix to be able to log asm functions.

Signed-off-by: Michal Simek <monstr@monstr.eu>

microblaze_mmu_v2: uaccess MMU update

Signed-off-by: Michal Simek <monstr@monstr.eu>