We'd like all architectures to convert to ARCH_ATOMIC, as once all
architectures are converted it will be possible to make significant
cleanups to the atomics headers, and this will make it much easier to
generically enable atomic functionality (e.g. debug logic in the
instrumented wrappers).
As a step towards that, this patch migrates openrisc to ARCH_ATOMIC. The
arch code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and common
code wraps these with optional instrumentation to provide the regular
functions.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-26-mark.rutland@arm.com
The openrisc implementation of <asm/cmpxchg.h> pulls in <linux/bitops.h>,
so that it can refer to BITS_PER_BYTE. It also transitively relies on
this pulling in <linux/compiler.h> for READ_ONCE().
Replace the #include with <linux/bits.h> and <linux/compiler.h>.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: yamada.masahiro@socionext.com
Link: https://lore.kernel.org/lkml/1529412794-17720-5-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
OpenRISC only supports hardware instructions that perform 4 byte atomic
operations. For enabling qrwlocks for upcoming SMP support 1 and 2 byte
implementations are needed. To do this we leverage the 4 byte atomic
operations and shift/mask the 1 and 2 byte areas as needed.
This heavily borrows ideas and routines from sh and mips, which do
something similar.
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Stafford Horne <shorne@gmail.com>
When building allmodconfig this warning shows.
fs/ocfs2/file.c: In function 'ocfs2_file_write_iter':
./arch/openrisc/include/asm/cmpxchg.h:81:3: warning: value computed is
not used [-Wunused-value]
((typeof(*(ptr)))__xchg((unsigned long)(with), (ptr), sizeof(*(ptr))))
^
Applying the same patch logic that was done to the cmpxchg macro.
Signed-off-by: Stafford Horne <shorne@gmail.com>
Optimized version that make use of the l.lwa and l.swa atomic instruction
pair.
Most openrisc cores provide these instructions now, if not available
emulation is provided.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
[shorne@gmail.com: remove OPENRISC_HAVE_INST_LWA_SWA config suggesed by
Alan Cox https://lkml.org/lkml/2014/7/23/666]
[shorne@gmail.com: fixed unused calculated value compiler warning in
define cmpxchg]
Signed-off-by: Stafford Horne <shorne@gmail.com>
