Previous SLC management implementation is broken. Seems like it was
never sufficiently tested probably because most of the time IOC was used
instead (i.e. no manual cache operations were done).

Now if we disable IOC in U-boot we'll get a lot of errors while using
DMA-enabled peripherals.

This time we fix it by substitution of broken per-line SLC operations
region operations as it is done in the Linux kernel (we took it from
v4.14 which is the latest stable as of today).

Among other things this implementation might be a bit faster because
instead of iteration over each and every cache line we're taking care
about entire region in one go.

Main changes:
 * Replaced __slc_line_op (per line operations) by __slc_rgn_op
   (region operations).

 * Reworked __slc_entire_op to get rid of __after_slc_op and
   __before_slc_op functions.
   Note flush fix (flush only instead of flush-n-inv when OP_FLUSH is
   used, see [1] for more details) is already incorporated here.

 * Added SLC invalidation to invalidate_icache_all().

 * Added (start >= end) check to invalidate_dcache_range() and
   flush_dcache_range() as some buggy drivers pass region start == end.

 * Added read-out of MMU BCR so we may know if PAE40 exists in HW and then
   act on a particular AUX regs accordingly.

[1] http://lists.infradead.org/pipermail/linux-snps-arc/2018-January/003357.html

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

ARCNUM [15:8] field in ARC_AUX_IDENTITY register allows us to
uniquely identify each core in a multi-core system.

I.e. with help of this macro each core may get its index in SMP system.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

With CONFIG_CMD_GPIO compilation reports error:
-------------------------->8---------------------
common/cmd_gpio.c:13:22: fatal error: asm/gpio.h: No such file or directory
 #include <asm/gpio.h>
                      ^
-------------------------->8---------------------

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Convert the arc architecture to make use of the new asm-generic/io.h to
provide address mapping functions. As the generic implementations are
suitable for arc this is primarily a matter of removing code.

Feedback from architecture maintainers is welcome.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Alexey Brodkin <alexey.brodkin@synopsys.com>
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>

Rather than including this arch-specific header file in common.h, include
it from within arc's u-boot.h header.

Signed-off-by: Simon Glass <sjg@chromium.org>

This header file is used by three archs. It could be used by all of them
since relocation is a common function. Move it into a generic file.

Signed-off-by: Simon Glass <sjg@chromium.org>

This header file is used by two archs. It could be used by all of them
since it allows the cache to be on during relocation. Move it into a
generic file.

Signed-off-by: Simon Glass <sjg@chromium.org>

This commit introduces timer driver for ARC.

ARC timers are configured via ARC AUX registers so we use special
functions to access timer control registers.

This driver allows utilization of either timer0 or timer1
depending on which one is available in real hardware. Essentially
only existing timers should be mentioned in board's Device Tree
description.

Signed-off-by: Vlad Zakharov <vzakhar@synopsys.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

This converts the following to Kconfig:
   CONFIG_ARCH_EARLY_INIT_R

Signed-off-by: Simon Glass <sjg@chromium.org>