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>
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>
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>
[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>
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>
This change allows to keep board description clean and minimalistic.
This is especially helpful if one board may house different CPUs with
different features.
It is applicable to both FPGA-based boards or those that have CPUs
mounted on interchnagable daughter-boards.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Now we may select a particular version of ARC700:
* ARC750D or
* ARC770D
It allows more flexible (or more fine tuned) configuration of U-Boot.
Before that change we relied on minimal configuration but now we may
use specific features of each CPU.
Moreover allows us to escape manual selection of options that
exist in both CPUs but may have say different version like MMUv2 in
ARC750D vs MMUv3 in ARC770D.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
These are header files used by ARC700 architecture.
Also note that "arch-arc700/hardware.h" is only required for compilation of
"designware_i2c" driver which refers to "asm/arch/hardware.h".
It would be good to fix mentioned driver sometime soon but it will cause
changes in ARM board configs that use "designware_i2c".
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Francois Bedard <fbedard@synopsys.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Tom Rini
Eugeniy Paltsev
Alexey Brodkin
Alexey Brodkin