Re: [PATCH 3/3] bitops.h: set_mask_bits() to return old value
On Thu, Jan 10, 2019 at 04:26:27PM -0800, Vineet Gupta wrote:
> @@ -246,7 +246,7 @@ static __always_inline void __assign_bit(long nr,
> volatile unsigned long *addr,
> new__ = (old__ & ~mask__) | bits__; \
> } while (cmpxchg(ptr, old__, new__) != old__); \
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 705f7c442691..2060d26a35f5 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -241,10 +241,10 @@ static __always_inline void __assign_bit(long nr,
volatile unsigned long *addr,
const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \
typeof(*(ptr)) old__, new__;\
\
+ old__ = READ_ONCE(*(ptr)); \
do {\
- old__ = READ_ONCE(*(ptr)); \
new__ = (old__ & ~mask__) | bits__; \
- } while (cmpxchg(ptr, old__, new__) != old__); \
+ } while (!try_cmpxchg(ptr, &old__, new__)); \
\
new__; \
})
While there you probably want something like the above... although,
looking at it now, we seem to have 'forgotten' to add try_cmpxchg to the
generic code :/
___
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[PATCH] webkitgtk: Enable building for ARC architecture
For that we need 2 things: 1. Disable JIT in JS as it's not supported for ARC. 2. Compile with "-mlong-calls" so relocations with offsets larger than 25 bits are used, otherwise linker fails to link final binaries. Signed-off-by: Alexey Brodkin Cc: Alexander Kanavin Cc: Hongxu Jia --- meta/recipes-sato/webkit/webkitgtk_2.22.5.bb | 7 +++ 1 file changed, 7 insertions(+) diff --git a/meta/recipes-sato/webkit/webkitgtk_2.22.5.bb b/meta/recipes-sato/webkit/webkitgtk_2.22.5.bb index fc56822f7a..56f69c7a30 100644 --- a/meta/recipes-sato/webkit/webkitgtk_2.22.5.bb +++ b/meta/recipes-sato/webkit/webkitgtk_2.22.5.bb @@ -69,6 +69,13 @@ EXTRA_OECMAKE = " \ EXTRA_OECMAKE_append_x86 = " -DUSE_GSTREAMER_GL=OFF " EXTRA_OECMAKE_append_x86-x32 = " -DUSE_GSTREAMER_GL=OFF " +# Javascript JIT is not supported on ARC +EXTRA_OECMAKE_append_arc = " -DENABLE_JIT=OFF " +# By default 25-bit "medium" calls are used on ARC +# which is not enough for binaries larger than 32 MiB +CFLAGS_append_arc = " -mlong-calls" +CXXFLAGS_append_arc = " -mlong-calls" + # Javascript JIT is not supported on powerpc EXTRA_OECMAKE_append_powerpc = " -DENABLE_JIT=OFF " EXTRA_OECMAKE_append_powerpc64 = " -DENABLE_JIT=OFF " -- 2.16.2 ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH] webkitgtk: Enable building for ARC architecture
On Fri, Jan 11, 2019 at 4:50 AM Alexey Brodkin wrote: > > For that we need 2 things: > 1. Disable JIT in JS as it's not supported for ARC. > > 2. Compile with "-mlong-calls" so relocations with > offsets larger than 25 bits are used, otherwise > linker fails to link final binaries. > > Signed-off-by: Alexey Brodkin > Cc: Alexander Kanavin > Cc: Hongxu Jia > --- > meta/recipes-sato/webkit/webkitgtk_2.22.5.bb | 7 +++ > 1 file changed, 7 insertions(+) > > diff --git a/meta/recipes-sato/webkit/webkitgtk_2.22.5.bb > b/meta/recipes-sato/webkit/webkitgtk_2.22.5.bb > index fc56822f7a..56f69c7a30 100644 > --- a/meta/recipes-sato/webkit/webkitgtk_2.22.5.bb > +++ b/meta/recipes-sato/webkit/webkitgtk_2.22.5.bb > @@ -69,6 +69,13 @@ EXTRA_OECMAKE = " \ > EXTRA_OECMAKE_append_x86 = " -DUSE_GSTREAMER_GL=OFF " > EXTRA_OECMAKE_append_x86-x32 = " -DUSE_GSTREAMER_GL=OFF " > > +# Javascript JIT is not supported on ARC > +EXTRA_OECMAKE_append_arc = " -DENABLE_JIT=OFF " > +# By default 25-bit "medium" calls are used on ARC > +# which is not enough for binaries larger than 32 MiB > +CFLAGS_append_arc = " -mlong-calls" > +CXXFLAGS_append_arc = " -mlong-calls" perhaps adding to CPPFLAGS is going to be enough for both c/c++ cases > + > # Javascript JIT is not supported on powerpc > EXTRA_OECMAKE_append_powerpc = " -DENABLE_JIT=OFF " > EXTRA_OECMAKE_append_powerpc64 = " -DENABLE_JIT=OFF " > -- > 2.16.2 > ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH 3/3] bitops.h: set_mask_bits() to return old value
On 1/11/19 1:24 AM, Peter Zijlstra wrote:
> diff --git a/include/linux/bitops.h b/include/linux/bitops.h
> index 705f7c442691..2060d26a35f5 100644
> --- a/include/linux/bitops.h
> +++ b/include/linux/bitops.h
> @@ -241,10 +241,10 @@ static __always_inline void __assign_bit(long nr,
> volatile unsigned long *addr,
> const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \
> typeof(*(ptr)) old__, new__;\
> \
> + old__ = READ_ONCE(*(ptr)); \
> do {\
> - old__ = READ_ONCE(*(ptr)); \
> new__ = (old__ & ~mask__) | bits__; \
> - } while (cmpxchg(ptr, old__, new__) != old__); \
> + } while (!try_cmpxchg(ptr, &old__, new__)); \
> \
> new__; \
> })
>
>
> While there you probably want something like the above...
As a separate change perhaps so that a revert (unlikely as it might be) could be
done with less pain.
> although,
> looking at it now, we seem to have 'forgotten' to add try_cmpxchg to the
> generic code :/
So it _has_ to be a separate change ;-)
But can we even provide a sane generic try_cmpxchg. The asm-generic cmpxchg
relies
on local irq save etc so it is clearly only to prevent a new arch from failing
to
compile. atomic*_cmpxchg() is different story since atomics have to be provided
by
arch.
Anyhow what is more interesting is the try_cmpxchg API itself. So commit
a9ebf306f52c756 introduced/use of try_cmpxchg(), which indeed makes the looping
"nicer" to read and obvious code gen improvements.
So,
for (;;) {
new = val $op $imm;
old = cmpxchg(ptr, val, new);
if (old == val)
break;
val = old;
}
becomes
do {
} while (!try_cmpxchg(ptr, &val, val $op $imm));
But on pure LL/SC retry based arches, we still end up with generated code
having 2
loops. We discussed something similar a while back: see [1]
First loop is inside inline asm to retry LL/SC and the outer one due to code
above. Explicit return of try_cmpxchg() means setting up a register with a
boolean
status of cmpxchg (AFAIKR ARMv7 already does that but ARC e.g. uses a CPU flag
thus requires an additional insn or two). We could arguably remove the inline
asm
loop and retry LL/SC from the outer loop, but it seems cleaner to keep the retry
where it belongs.
Also under the hood, try_cmpxchg() would end up re-reading it for the issue
fixed
by commit 44fe84459faf1a.
Heck, it would all be simpler if we could express this w/o use of cmpxchg.
try_some_op(ptr, &val, val $op $imm);
P.S. the horrible API name is for indicative purposes only
This would remove the outer loop completely, also avoid any re-reads due to the
semantics of cmpxchg etc.
[1] https://www.spinics.net/lists/kernel/msg2029217.html
___
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc
kisskb: OK linus/axs103_smp_defconfig/arcv2 Sat Jan 12, 08:09
OK linus/axs103_smp_defconfig/arcv2 Sat Jan 12, 08:09
http://kisskb.ellerman.id.au/kisskb/buildresult/13649951/
Commit: Merge tag 'pci-v5.0-fixes-1' of
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
de6629eb262e0dc52a2367db38e3d2780cff5427
Compiler: arc-linux-gcc.br_real (Buildroot 2016.11-git-00613-ge98b4dd) 6.2.1
20160824 / GNU ld (GNU Binutils) 2.27.51.20160928
Possible errors
---
arch/arc/boot/dts/axs10x_mb.dtsi:221.15-225.6: Warning (i2c_bus_reg):
/axs10x_mb/i2c@0x1f000/eeprom@0x54: I2C bus unit address format error, expected
"54"
arch/arc/boot/dts/axs10x_mb.dtsi:227.15-231.6: Warning (i2c_bus_reg):
/axs10x_mb/i2c@0x1f000/eeprom@0x57: I2C bus unit address format error, expected
"57"
#define KERN_ERR KERN_SOH "3" /* error conditions */
#define KERN_ERR KERN_SOH "3" /* error conditions */
#define KERN_ERR KERN_SOH "3" /* error conditions */
Possible warnings (83)
--
arch/arc/boot/dts/axs10x_mb.dtsi:221.15-225.6: Warning (i2c_bus_reg):
/axs10x_mb/i2c@0x1f000/eeprom@0x54: I2C bus unit address format error, expected
"54"
arch/arc/boot/dts/axs10x_mb.dtsi:227.15-231.6: Warning (i2c_bus_reg):
/axs10x_mb/i2c@0x1f000/eeprom@0x57: I2C bus unit address format error, expected
"57"
kernel/dma/direct.c:40:4: warning: format '%zu' expects argument of type
'size_t', but argument 4 has type 'unsigned int' [-Wformat=]
arch/arc/mm/tlb.c:914:2: warning: ISO C90 forbids variable length array 'pd0'
[-Wvla]
include/linux/kernel.h:846:29: warning: comparison of distinct pointer types
lacks a cast
include/linux/kernel.h:846:29: warning: comparison of distinct pointer types
lacks a cast
include/linux/kernel.h:846:29: warning: comparison of distinct pointer types
lacks a cast
include/linux/kernel.h:846:29: warning: comparison of distinct pointer types
lacks a cast
include/linux/kernel.h:846:29: warning: comparison of distinct pointer types
lacks a cast
include/linux/kernel.h:846:29: warning: comparison of distinct pointer types
lacks a cast
include/linux/kernel.h:846:29: warning: comparison of distinct pointer types
lacks a cast
fs/ext4/inode.c:3654:12: warning: format '%zd' expects argument of type 'signed
size_t', but argument 6 has type 'ssize_t {aka int}' [-Wformat=]
mm/percpu.c:1382:17: warning: format '%zu' expects argument of type 'size_t',
but argument 4 has type 'unsigned int' [-Wformat=]
mm/percpu.c:1382:17: warning: format '%zu' expects argument of type 'size_t',
but argument 5 has type 'unsigned int' [-Wformat=]
include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of
type 'size_t', but argument 2 has type 'unsigned int' [-Wformat=]
#define KERN_WARNING KERN_SOH "4" /* warning conditions */
include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of
type 'size_t', but argument 3 has type 'unsigned int' [-Wformat=]
#define KERN_WARNING KERN_SOH "4" /* warning conditions */
mm/percpu.c:1948:27: warning: format '%zu' expects argument of type 'size_t',
but argument 3 has type 'unsigned int' [-Wformat=]
mm/percpu.c:1948:32: warning: format '%zu' expects argument of type 'size_t',
but argument 4 has type 'unsigned int' [-Wformat=]
mm/percpu.c:1948:37: warning: format '%zu' expects argument of type 'size_t',
but argument 5 has type 'unsigned int' [-Wformat=]
mm/percpu.c:1948:42: warning: format '%zu' expects argument of type 'size_t',
but argument 6 has type 'unsigned int' [-Wformat=]
mm/percpu.c:1948:52: warning: format '%zu' expects argument of type 'size_t',
but argument 7 has type 'unsigned int' [-Wformat=]
mm/percpu.c:1948:56: warning: format '%zu' expects argument of type 'size_t',
but argument 8 has type 'unsigned int' [-Wformat=]
include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of
type 'size_t', but argument 2 has type 'unsigned int' [-Wformat=]
include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of
type 'size_t', but argument 4 has type 'unsigned int' [-Wformat=]
include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of
type 'size_t', but argument 5 has type 'unsigned int' [-Wformat=]
include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of
type 'size_t', but argument 6 has type 'unsigned int' [-Wformat=]
include/linux/kern_levels.h:5:18: warning: format '%zu' expects argument of
type 'size_t', but argument 7 has type 'unsigned int' [-Wformat=]
include/linux/kern_levels.h:5:18: warning: format '%zd' expects argument of
type 'signed size_t', but argument 3 has type 'size_t {aka unsigned int}'
[-Wformat=]
include/linux/kernel.h:846:29: warning: comparison of distinct pointer types
lacks a cast
drivers/gpu/drm/drm_dp_helper.c:820:18: warning: format '%zu' expects argument
of type 'size_t', but argument 4 has type 'unsigned int' [-Wformat=]
drivers/gpu/drm/drm_dp_helper.c:853:18: warning: format '%zu' expects argument
of type 'size_t', but argument 4 has type 'unsigned int' [-Wformat=]
drivers/gpu/dr
kisskb: OK linus/axs101_defconfig/arcompact Sat Jan 12, 08:09
OK linus/axs101_defconfig/arcompact Sat Jan 12, 08:09 http://kisskb.ellerman.id.au/kisskb/buildresult/13649952/ Commit: Merge tag 'pci-v5.0-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci de6629eb262e0dc52a2367db38e3d2780cff5427 Compiler: arc-buildroot-linux-uclibc-gcc (Buildroot 2015.08.1) 4.8.4 / GNU ld (GNU Binutils) 2.23.2 Possible errors --- arch/arc/boot/dts/axs10x_mb.dtsi:221.15-225.6: Warning (i2c_bus_reg): /axs10x_mb/i2c@0x1f000/eeprom@0x54: I2C bus unit address format error, expected "54" arch/arc/boot/dts/axs10x_mb.dtsi:227.15-231.6: Warning (i2c_bus_reg): /axs10x_mb/i2c@0x1f000/eeprom@0x57: I2C bus unit address format error, expected "57" Possible warnings (8) -- arch/arc/boot/dts/axs10x_mb.dtsi:221.15-225.6: Warning (i2c_bus_reg): /axs10x_mb/i2c@0x1f000/eeprom@0x54: I2C bus unit address format error, expected "54" arch/arc/boot/dts/axs10x_mb.dtsi:227.15-231.6: Warning (i2c_bus_reg): /axs10x_mb/i2c@0x1f000/eeprom@0x57: I2C bus unit address format error, expected "57" arch/arc/mm/tlb.c:914:2: warning: variable length array 'pd0' is used [-Wvla] arch/arc/include/asm/cmpxchg.h:95:29: warning: value computed is not used [-Wunused-value] arch/arc/include/asm/cmpxchg.h:95:29: warning: value computed is not used [-Wunused-value] arch/arc/include/asm/cmpxchg.h:95:29: warning: value computed is not used [-Wunused-value] net/ipv4/tcp_input.c:4324:49: warning: array subscript is above array bounds [-Warray-bounds] include/linux/kernel.h:846:29: warning: comparison of distinct pointer types lacks a cast [enabled by default] ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
