Re: [PATCH v1 18/29] xen/asm-generic: introduce stub header smp.h

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

On Thu, 2023-10-19 at 12:58 +0200, Jan Beulich wrote:
> On 14.09.2023 16:56, Oleksii Kurochko wrote:
> > The patch introduces header stub necessry for full Xen build.
> > 
> > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> 
> Assuming you expect RISC-V to get away without its own smp.h, just
> one remark:
Not really, I've introduced only things necessary for Xen's full build.

It looks like we have a situation as with device.h header ( in this
patch series) . Probably smp.h header should be only in an arch-
specific folder. I'll apply to smp.h the same solution as for device.h
when we get to the same page on it.

Except what I introduced in this patch other functions and macros will
be in smp.h. Such as:

raw_smp_processor_id
smp_processor_id
extern void smp_clear_cpu_maps (void);
extern void smp_init_cpus(void);
extern unsigned int smp_get_max_cpus(void);
void smp_setup_processor_id(unsigned long boot_cpu_id);

/*
 * Mapping between linux logical cpu index and hartid.
 */
extern unsigned long __cpuid_to_hartid_map[NR_CPUS];
#define cpuid_to_hartid_map(cpu) __cpuid_to_hartid_map[cpu]

#define cpu_physical_id(cpu) cpuid_to_hartid_map(cpu)

Mostly all of the header can be generic but again all the mentioned
above functions are used only for RISC-V and ARM. ( probably I missed
something ).

> 
> > --- /dev/null
> > +++ b/xen/include/asm-generic/smp.h
> > @@ -0,0 +1,30 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +#ifndef __ASM_GENERIC_SMP_H
> > +#define __ASM_GENERIC_SMP_H
> > +
> > +#ifndef __ASSEMBLY__
> > +#include <xen/cpumask.h>
> > +#include <xen/percpu.h>
> > +#endif
> 
> This #endif need moving ...
> 
> > +DECLARE_PER_CPU(cpumask_var_t, cpu_sibling_mask);
> > +DECLARE_PER_CPU(cpumask_var_t, cpu_core_mask);
> 
> ... at least down here, if #includ-ing by assembly files is really
> necessary to permit. Preferably the #ifndef would be dropped, though.
> 
> Jan

~ Oleksii