When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>

Implement specialized function to clenup caches (and therefore
sync instruction and data caches) which can be used for cleanup before linux
launch or to sync caches during U-Boot self-relocation.

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

Use CONFIG_ARC_DBG_IOC_ENABLE Kconfig option instead of
ioc_enable global variable.

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

There is a problem with current implementation if we start U-Boot
from ROM, as we use global variables before ther initialization,
so these variables get overwritten when we copy .data section
from ROM.

Instead we move these global variables into our "global data"
structure so that we may really start from ROM.

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

We're starting to use more and more BCRs and having their
definitions in-lined in sources becomes a bit annoying
so we move it all to a separate header.

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

We don't implement separate flush_dcache_all() intentionally as
entire data cache invalidation is dangerous operation even if we flush
data cache right before invalidation.

There is the real example:
We may get stuck in the following code if we store any context (like
BLINK register) on stack in invalidate_dcache_all() function.

BLINK register is the register where return address is automatically saved
when we do function call with instructions like 'bl'.

void flush_dcache_all() {
	__dc_entire_op(OP_FLUSH);
	// Other code //
}

void invalidate_dcache_all() {
	__dc_entire_op(OP_INV);
	// Other code //
}

void foo(void) {
	flush_dcache_all();
	invalidate_dcache_all();
}

Now let's see what really happens during that code execution:

foo()
  |->> call flush_dcache_all
  	[return address is saved to BLINK register]
  	[push BLINK] (save to stack)              ![point 1]
  	|->> call __dc_entire_op(OP_FLUSH)
  		[return address is saved to BLINK register]
  		[flush L1 D$]
  		return [jump to BLINK]
  	<<------
  	[other flush_dcache_all code]
  	[pop BLINK] (get from stack)
  	return [jump to BLINK]
  <<------
  |->> call invalidate_dcache_all
  	[return address is saved to BLINK register]
  	[push BLINK] (save to stack)               ![point 2]
  	|->> call __dc_entire_op(OP_FLUSH)
  		[return address is saved to BLINK register]
  		[invalidate L1 D$]                 ![point 3]
  		// Oops!!!
  		// We lose return address from invalidate_dcache_all function:
  		// we save it to stack and invalidate L1 D$ after that!
  		return [jump to BLINK]
  	<<------
  	[other invalidate_dcache_all code]
  	[pop BLINK] (get from stack)
  	// we don't have this data in L1 dcache as we invalidated it in [point 3]
  	// so we get it from next memory level (for example DDR memory)
  	// but in the memory we have value which we save in [point 1], which
  	// is return address from flush_dcache_all function (instead of
  	// address from current invalidate_dcache_all function which we
  	// saved in [point 2] !)
  	return [jump to BLINK]
  <<------
  // As BLINK points to invalidate_dcache_all, we call it again and
  // loop forever.

Fortunately we may do flush and invalidation of D$ with a single one
instruction which automatically mitigates a situation described above.

And because invalidate_dcache_all() isn't used in common U-Boot code we
implement "flush and invalidate dcache all" instead.

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

Introduce is_isa_arcv2() and is_isa_arcompact() functions.

These functions only check configuration options and return
compile-time constant so they can be used instead of #ifdef's to
to write cleaner code.

Now we can write:
-------------->8---------------
if (is_isa_arcv2())
	ioc_configure();
-------------->8---------------
instead of:
-------------->8---------------
ifdef CONFIG_ISA_ARCV2
	ioc_configure();
endif
-------------->8---------------

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

We improve on 2 things:
 1. Only ARC HS family has "dmb" instructions so do compile-time
    check for automatically defined macro __ARCHS__.
    Previous check for ARCv2 ISA was not good enough because ARC EM
    family is v2 ISA as well but still "dmb" instaruction is not
    supported in EM family.

 2. Still if there's no dedicated instruction for memory barrier
    let's at least insert compile-time barrier to make sure
    compiler deosn't reorder critical memory operations.

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

U-Boot is a bit special piese of software because it is being
only executed once on power-on as compared to operating system
for example. That's why we don't care much about performance
optimizations instead we're more concerned about size. And up-to-date
compilers might produce much smaller code compared to
performance-optimized routines copy-pasted from the Linux kernel.

Here's an example:
------------------------------->8--------------------------
--- size_asm_strings.txt
+++ size_c_strings.txt
@@ -1,2 +1,2 @@
    text	   data	    bss	    dec	    hex	filename
- 121260	   3784	   3308	 128352	  1f560	u-boot
+ 120448	   3784	   3308	 127540	  1f234	u-boot
------------------------------->8--------------------------

See we were able to shave off ~800 bytes of .text section.

Also usage of string routines implemented in C gives us an ability
to support more HW flavors for free: generated instructions will match
our target as long as correct compiler option is used.

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

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 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>

Unlike Linux, nothing about errno.h is arch-specific in U-Boot.
As you see, all of arch/${ARCH}/include/asm/errno.h is just a
wrapper of <asm-generic/errno.h>.  Actually, U-Boot does not
export headers to user-space, so we just have to care about the
consistency in the U-Boot tree.

Now all of include directives for <asm/errno.h> are gone.
Deprecate <asm/errno.h>.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>

Starting from arc-2016.03 GNU tools linker properly works with
symbols defined in linker script and so external declarations
are no longer required, dump them.

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

Currently on attempt to use global_data.h in an assembly file following
will happen:
-------------------->8-----------------
./arch/arc/include/asm/global_data.h: Assembler messages:
./arch/arc/include/asm/global_data.h:11: Error: bad instruction 'struct arch_global_data{'
./arch/arc/include/asm/global_data.h:12: Error: junk at end of line, first unrecognized character is `}'
scripts/Makefile.build:316: recipe for target 'arch/arc/lib/start.o' failed
-------------------->8-----------------

In this change we disable struct arch_global_data in ASM which fixes
the issue above.

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

Memory barriers are proven to be a requirement for both compiler and
real hardware to properly serialize access to critical data.

For example if CPU or data bus it uses may do reordering of data
accesses absence of memory barriers might easily lead to very subtle and
hard to debug data corruptions.

This implementation was heavily borrowed from up to date Linux kernel.

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

Commit cf7c93cd "usb: ehci: Implement V2P mapping"
introduced usage of virt_to_phys() in ehci-hcd.

Since there was no implementation of virt_to_phys() for ARC
compilation of the ehci-generic driver failed.

This change adds virt_to_phys() stub for ARC so now
USB driver for AXS101 board could be built again.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Acked-by: Marek Vasut <marex@denx.de>

ISS is obsolete now and nSIM is used for simulation instead.
In its turn nSIM properly handles baud-rate settings so get rid
of now useless check.

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

With release of ARC HS38 v2.1 new IO coherency engine could be built-in
ARC core. This hardware module ensures coherency between DMA-ed data
from peripherals and L2 cache.

With L2 and IOC enabled there's no overhead for L2 cache manual
maintenance which results in significantly improved IO bandwidth.

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

ARC core could be configured with different L1 and L2 (AKA SLC) cache
line lengths. At least these values are possible and were really used:
32, 64 or 128 bytes.

Current implementation requires cache line to be selected upon U-Boot
configuration and then it will only work on matching hardware. Indeed
this is quite efficient because cache line length gets hardcoded during
code compilation. But OTOH it makes binary less portable.

With this commit we allow U-Boot to determine real L1 cache line length
early in runtime and use this value later on. This extends portability
of U-Boot binary a lot.

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

common/usb.c unconditionally includes <asm/processor.h>
And now to allow USB support on ARC boards we have to have that header.

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

Up until now there was no need in those stubs.

But since following commit compilation of U-Boot on ARC is broken:
------------------------>8----------------------
commit 7861204c
Author: Stephen Warren <swarren@wwwdotorg.org>
Date:   Sat Oct 3 13:56:46 2015 -0600

    itest: make memory access work under sandbox

    itest accesses memory, and hence must map/unmap it. Without doing so, it
    accesses invalid addresses and crashes.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
------------------------>8----------------------

That's because CMD_ITEST is enabled by default in common/Kconfig and now
map_physmem()/unmap_physmem() is used there.

So this patch adds missing stubs for ARC.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>

The generic bitops headers are required when calling logarithmic
functions, such as ilog2().

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

[1] Align cache management functions to those in Linux kernel. I.e.:
    a) Use the same functions for all cache ops (D$ Inv/Flush)
    b) Split cache ops in 3 sub-functions: "before", "lineloop" and
"after". That way we may re-use "before" and "after" functions for
region and full cache ops.

 [2] Implement full-functional L2 (SLC) management. Before SLC was
simply disabled early on boot. It's also possible to enable or disable
L2 cache from config utility.

 [3] Disable/enable corresponding caches early on boot. So if U-Boot is
configured to use caches they will be used at all times (this is useful
in partucular for speed-up of relocation).

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

ARCv2 cores may have built-in SLC (System Level Cache, AKA L2-cache).
This change adds functions required for controlling SLC:
 * slc_enable/disable
 * slc_flush/invalidate

For now we just disable SLC to escape DMA coherency issues until either:
 * SLC flush/invalidate is supported in DMA APIin U-Boot
 * hardware DMA coherency is implemented (that might be board specific
   so probably we'll need to have a separate Kconfig option for
   controlling SLC explicitly)

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

As discussed on mailing list we're drifting away from
CONFIG_SYS_GENERIC_GLOBAL_DATA in favour to use of board_init_f_mem()
for global data.

So do this for ARC architecture.

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

Intention behind this work was elimination of as much assembly-written
code as it is possible.

In case of ARC we already have relocation fix-up implemented in C so why
don't we use C for U-Boot copying, .bss zeroing etc.

It turned out x86 uses pretty similar approach so we re-used parts of
code in "board_f.c" initially implemented for x86.

Now assembly usage during init is limited to stack- and frame-pointer
setup before and after relocation.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Simon Glass <sjg@chromium.org>

We have done with the generic board conversion for all the boards
of ARC, Blackfin, M68000, MicroBlaze, MIPS, NIOS2, Sandbox, X86.

Let's select SYS_GENERIC_BOARD for those architectures, so we can
tell which architecture has finished the conversion at a glance.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com>

For some assemblers, they use another character as newline in a macro
(e.g. arc uses '`'), so for generic assembly code, need use ASM_NL (a
macro) instead of ';' for it.

Basically this is the same patch as applied to Linux kernel -
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/include/linux/linkage.h?id=9df62f054406992ce41ec4558fca6a0fa56fffeb



but modified a bit to fit in U-Boot.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@ti.com>

ARC HS and ARC EM are new cores based on ARCv2 ISA which is binary
incompatible with ISAv1 (AKA ARCompact).

Significant difference between ISAv2 and v1 is implementation of
interrupt vector table.

In v1 it is implemented in the same way as on many other architectures -
as a special location where user may put whether code executed in place
(if machine word of space is enough) or jump to a full-scale interrupt
handler.

In v2 interrupt table is just an array of adresses of real interrupt
handlers. That requires a separate section for IVT that is not encoded
as code by assembler.

This change adds support for following cores:
 * ARC EM6 (simple 32-bit microcontroller without MMU)
 * ARC HS36 (advanced 32-bit microcontroller without MMU)
 * ARC HS38 (advanced 32-bit microcontroller with MMU)

As a part of ARC HS38 new version of MMU (v4) was introduced.

Also this change adds AXS131 board which is the same DW ARC SDP base board but
with ARC HS38 CPU tile.

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

Common arch_early_init_r() is used in "arc/lib/cpu.c" for all ARC boards
so there's no sense in separate per-board definitions.

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

There're no other options for ARC except "generic board" so ther's no
point to define CONFIG_SYS_GENERIC_BOARD per board.

We now have it set fo all ARC boards.

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