This will allow for board-specific implementation of reset.
Default version will just stop execution with help of BRK instruction.

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

For quite some time we have a GCC's built-in which inserts BRK
instruction so let's use it instead of simple insertion of in-line
assembly.

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

We used to have the one and only linker script for all ARC boards
and so we relied on a particular order of symbols there.

Because of that we used __ivt_end as the marker of the end of all the
code which won't be true any longer if we move .ivt section to any other
place. That said we'd better check for each section separately.

A couple of other improvements:
 1. There's no point to include the marker of section end in interested
    range because its address is beyond the section, i.e. we should
    compare with "<" but not "<=".

 2. .ivt section for ARCv2 cores is just an array of 32-bit ints and
    they are not swapped even on little-endia cores while in case of
    ARCompact cores .ivt contains valid code so swapping is required.

 3. Just in case add check for ARC600 which is also ARCompact
    and its .ivt is normal code.

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

We don't care much about I$ line length really as there're
no per-line ops on I$ instead we only do full invalidation of it
on occasion of relocation and right before jumping to the OS.

Also as compared to Linux kernel where we don't support different
lengths of I$ and D$ lines in U-Boot we have to deal with such an
exotic configs if the target board is not supposed to run Linux kernel.

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

The debug UART is intended for use very early in U-Boot to debug
problems before serial drivers are up.

Call debug_uart_init right before board_init_f.

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

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>

"Global data" structure "gd" is not used in init_helpers.c
thus DECLARE_GLOBAL_DATA_PTR might be safely removed.

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

Refactor GO and PREP subcommands implementation for a simpler
override in the boards platform code.

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

Move all checks before cache flush and IOC setup.

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

Add missing cache cleanup before cache disable:
 * Flush and invalidate L1 D$ before disabling. Flush and invalidate
   SLC before L1 D$ disabling (as it will be bypassed for data)
   Otherwise we can lose some data when we disable L1 D$ if this data
   isn't flushed to next level cache. Or we can get wrong data if L1 D$
   has some entries after enable which we modified when the L1 D$ was
   disabled.
 * Invalidate L1 I$ before disabling. Otherwise we can execute wrong
   instructions after L1 I$ enable if we modified any code when
   L1 I$ was disabled.

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

Add additional cache configuration checks and note about
supported configurations.

It is unlikely to face some configuration in real life but
it's better to be prepared and refuse to work on those.

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

If L1 D$ is disabled SLC is bypassed for data and all
load/store requests are sent directly to main memory.

If L1 I$ is disabled SLC is NOT bypassed for instructions
and all instruction requests are fetched through SLC.

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

Implement icache_enabled() and dcache_enabled() as separate functions
which can be used with "inline" attribute. This is a preparation to
make them always_inline.

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>

Move check for PAE existence into slc_upper_region_init()
instead of its caller as more appropriate place.

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>

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'll use icache_exists(), dcache_exists(), slc_exists(), pae_exists()
functions which directly check BCRs every time.

In U-Boot case ops are used only during self-relocation and DMA
so we shouldn't be hit by noticeable performance degradation.

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

As of today we check SLC status before each call of __slc_rgn_op()
or __slc_entire_op(). So move status check into __slc_rgn_op()
and __slc_entire_op().

As we need to check status before *each* function execution and we
call slc_entire_op() and slc_rgn_op() from different places we add
this check directly into SLC entire/line functions instead of
their callers to avoid code duplication.

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

Use is_isa_arcv2() function where it is possible instead of
CONFIG_ISA_ARCV2 define check to make code cleaner at the same time
keeping pretty much the same functionality - code in branches
under "if (is_isa_arcv2())" won't be compiled if CONFIG_ISA_ARCV2
is not defined, still we need a couple of CONFIG_ISA_ARCV2
ifdefs to make compiler happy. That's because code in
!is_isa_x() branch gets compiled and only then gets optimized
away.

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

As we are planning to get rid of dozens of ifdef's in cache.c we
would better check D$ status before each entire/line operation
then check CONFIG_SYS_DCACHE_OFF config option.

This makes the code cleaner as well as D$ entire/line functions
remain functional even if we enable or disable D$ in run-time.

As we need to check status before *each* function execution and we
call D$ entire/line functions from different places we add
this check directly into D$ entire/line functions instead of
their callers to avoid code duplication.

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>

Move IOC initialization from cache_init() to a separate function.

This is the preparation for the next patch where we'll switch
to is_isa_arcv2() function usage instead of "CONFIG_ISA_ARCV2"
ifdef.

Also it makes cache_init function a bit cleaner.

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>

As of today __dc_line_op() and __dc_entire_op() support
only separate flush (OP_FLUSH) and invalidate (OP_INV) operations.

Add support of combined flush and invalidate (OP_FLUSH_N_INV)
operation which we planing to use in subsequent patches.

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

__cache_line_loop() function was copied from Linux kernel
where per-line instruction cache operations are really used.

In U-Boot we use only entire I$ ops, so we can drop support of
per-line I$ ops from __cache_line_loop() because __cache_line_loop()
is never called with OP_INV_IC parameter.

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

Move instruction cache entire operation to a separate function
because we are planing to use it in other places like
sync_icache_dcache_all().

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

Disabling relocation might be useful on ARC for 2 reasons:
 a) For advanced debugging with Synopsys proprietary MetaWare debugger
    which is capable of accessing much more specific hardware resources
    compared to gdb. For example it may show contents of L1 and L2 caches,
    internal states of some hardware blocks etc.

    But on the downside MetaWare debugger still cannot work with PIE.
    Even though that limitation could be work-arounded with change of ELF's
    header and stripping down all debug info but with it we won't have
    debug info for source-level debugging which is quite inconvenient.

 b) Some platforms which might benefit from usage of U-Boot basically
    don't have enough RAM to accommodate relocation of U-Boot so we
    keep code in flash and use as much of RAM as possible for more
    interesting things.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: York Sun <york.sun@nxp.com>
Cc: Stefan Roese <sr@denx.de>

This commit basically reverts two commits:
 1. cf628f77 ("arc: arcv1: Disable master/slave check")
 2. 6cba327b ("arcv2: Halt non-master cores")

With mentioned commits in-place we experience more trouble than
benefits. In case of SMP Linux kernel this is really required as
we have all the cores running from the very beginning and then we
need to allow master core to do some preparatory work while slaves
are not getting in the way.

In case of U-Boot we:
 a) Don't really run more than 1 core in parallel
 b) We may use whatever core for that

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>

Only ARM and in some configs MIPS really implement arch_fixup_fdt().
Others just use the same boilerplate which is not good by itself,
but what's worse if we try to build with disabled CONFIG_CMD_BOOTM
and enabled CONFIG_OF_LIBFDT we'll hit an unknown symbol which was
apparently implemented in arch/xxx/lib/bootm.c.

Now with weak arch_fixup_fdt() right in image-fdt.c where it is
used we get both items highlighted above fixed.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: York Sun <york.sun@nxp.com>
Cc: Stefan Roese <sr@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

This is useful to make sure no stale data exists in caches after bootloaders.

The worst thing could be some lines of cache were locked in a bootloader
for example during DDR recalibration and never unlocked. This may lead
to really unpredictable issues later down the line.

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>

We'd like to keep IOC HW at the same state as t is right after reset when we
start Linux kernel so there will be no re-configuration of IOC on the go.

The point is U-Boot doesn't benefit a lot from IOC as it doesn't do a
lot of DMA operations especially on multiple cores simultaneously.

At the same time re-configuration of IOC in run-time might become quite
a tricky experience because we need to make sure there're no DMA
trannsactions in flight otherwise unexpected consequencses might affect
us much later and debugging those kinds of issues will be a real
nightmare.

That said let's make our life easier a little bit.

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

dcache_exists, icache_exists, slc_exists and ioc_exists global
variables in "arch/arc/lib/cache.c" remain uninitialized if
SoC doesn't have corresponding HW.

This happens because we use the next constructions for their
definition and initialization:
-------------------------->>---------------------
int ioc_exists __section(".data");

if (/* condition */)
		ioc_exists = 1;
-------------------------->>---------------------

That's quite a non-trivial issue as one may think of it.
The point is we intentionally put those variables in ".data" section
so they might survive relocation (remember we initilaize them very early
before relocation and continue to use after reloaction). While being
non-initialized and not explicitly put in .data section they would end-up
in ".bss" section which by definition is filled with zeroes.
But since we place those variables in .data section we need to care
about their proper initialization ourselves.

Also while at it we change their type to "bool" as more appropriate.

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

As per ARC HS databook (see chapter 5.3.3.2) it is required to add
3 NOPs after each write to IC_IVIC which we do from now on.

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

Currently slave cores will be kick-started even if we want
to dry run bootm which is not what we really want.

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

We are now using an env_ prefix for environment functions. Rename these
two functions for consistency. Also add function comments in common.h.

Quite a few places use getenv() in a condition context, provoking a
warning from checkpatch. These are fixed up in this patch also.

Suggested-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>

We used to use the same memory layout and size for a couple of
boards and thus we just hardcoding IOC aperture start and size.

Now when we're getting more boards with more memory on board we
need to have an ability to set IOC so it matches real DDR layout
and size.

Even though it is not really a must but for simplicity we assume
IOC covers all the DDR we have, that gives us a chance to not
bother where DMA buffers are allocated - any part of DDR is OK.

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