We add memory barriers for __raw_readX / __raw_writeX accessors same
way as it is done for readX and writeX accessors as lots of U-boot
driver uses __raw_readX / __raw_writeX instead of proper accessor
with barrier.
It will save us from lot's of debugging in the future and it is OK
as U-Boot is not that performance oriented as real run-time
software like OS or user bare-metal app so we may afford being not
super fast as we only being executed once.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
We must use compiler barriers in C-version read/write IO accessors
before and after operation (read or write) so it won't be reordered
by compiler.
Fixes commit 07906b3dad ("ARC: Switch to generic accessors")
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
We must use 'volatile' in C-version read/write IO accessors
implementation to avoid merging several reads (writes) into
one read (write), or optimizing them out by compiler.
Fixes commit 07906b3dad ("ARC: Switch to generic accessors")
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
First of all U-Boot is not that performance oriented as real run-time
software like OS or user bare-metal app so we may afford being not super
fast as we only being executed once. That in return allows us to be more
universal and support wider variety of devices.
And looking forward that will significantly reduce maintenance and simplify
support of newer architectures.
And while at it we add quad-word accessors like readq(), writeq() etc.
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>
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>
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>
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 cf7c93cdd7 "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>
Up until now there was no need in those stubs.
But since following commit compilation of U-Boot on ARC is broken:
------------------------>8----------------------
commit 7861204c9a
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>
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>
