Re: [PATCH] arm64: Fix compile error seen in non-SMP builds

[Guenter Roeck]

On 10/11/2014 06:16 AM, Frederic Weisbecker wrote:
> On Fri, Oct 10, 2014 at 06:15:34PM -0700, Guenter Roeck wrote:
> > Fix:
> >
> > In file included from ./arch/arm64/include/asm/irq_work.h:4:0,
> >          from include/linux/irq_work.h:46,
> >          from include/linux/perf_event.h:49,
> >          from include/linux/ftrace_event.h:9,
> >          from include/trace/syscall.h:6,
> >          from include/linux/syscalls.h:81,
> >          from init/main.c:18:
> > ./arch/arm64/include/asm/smp.h:24:3:
> > 	error: #error "<asm/smp.h> included in non-SMP build"
> >   # error "<asm/smp.h> included in non-SMP build"
> >     ^
> > ./arch/arm64/include/asm/smp.h:27:0: warning: "raw_smp_processor_id" redefined
> >   #define raw_smp_processor_id() (current_thread_info()->cpu)
> >   ^
> >
> > and:
> >
> > In file included from ./arch/arm64/include/asm/irq_work.h:4:0,
> >          from include/linux/irq_work.h:46,
> >          from kernel/irq_work.c:11:
> > ./arch/arm64/include/asm/smp_plat.h:56:30:
> >          error: âNR_CPUSâ undeclared here (not in a function)
> >          extern u64 __cpu_logical_map[NR_CPUS];
> >
> > by providing a helper function in smp_plat.h, similar to the arm implementation,
> > and by removing NR_CPUS from smp_plat.h.
> >
> > Fixes: 3631073659d0 ("arm64: Tell irq work about self IPI support")
> > Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
>
> That looks good to me.
>
> Note, ARM64 is one of the archs I couldn't test due to the lack of a
> nolibc cross compiler in https://www.kernel.org/pub/tools/crosstool/
No worries. Even if you had, you might not have caught the non-SMP case.
I only recently added a non-SMP build myself.

Is the toolchain issue out of principle (not wanting to use a cross
compiler that includes glibc) or because you did not find a cross
compiler ? Linaro provides toolchains for aarch64, though they are
only 32 bit. I built one myself using buildroot (select binutils 2.24
and gcc 4.9.1).

In general I have been quite successful using buildroot to create
toolchains, including ones for oddball architectures like score
(after patching buildroot to support it, of course).

Guenter

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/