From: Wei Liu <wei.liu@xxxxxxxxxx> Sent: Sunday, April 18, 2021 6:09 AM
> On Fri, Apr 16, 2021 at 05:43:02PM -0700, Joseph Salisbury wrote:
> > From: Joseph Salisbury <joseph.salisbury@xxxxxxxxxxxxx>
> >
> > This patch makes no functional changes. It simply moves hv_do_rep_hypercall()
> > out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h
> >
> > hv_do_rep_hypercall() is architecture independent, so it makes sense that it
> > should be in the architecture independent mshyperv.h, not in the x86-specific
> > mshyperv.h.
> >
> > This is done in preperation for a follow up patch which creates a consistent
> > pattern for checking Hyper-V hypercall status.
> >
> > Signed-off-by: Joseph Salisbury <joseph.salisbury@xxxxxxxxxxxxx>
> > ---
> [...]
> > +static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
> > + void *input, void *output)
> > +{
> > + u64 control = code;
> > + u64 status;
> > + u16 rep_comp;
> > +
> > + control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
> > + control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
> > +
> > + do {
> > + status = hv_do_hypercall(control, input, output);
> > + if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
> > + return status;
> > +
> > + /* Bits 32-43 of status have 'Reps completed' data. */
> > + rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
> > + HV_HYPERCALL_REP_COMP_OFFSET;
> > +
> > + control &= ~HV_HYPERCALL_REP_START_MASK;
> > + control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
> > +
> > + touch_nmi_watchdog();
>
> This seems to be missing in Arm. Does it compile?
>
> Wei.
touch_nmi_watchdog() is defined as "static inline" in include/linux/nmi.h. So
it should be present in all architectures. It calls arch_touch_nmi_watchdog,
which is an empty function if CONFIG_HAVE_NMI_WATCHDOG is not defined,
as is the case on ARM64.
Michael
>
> > + } while (rep_comp < rep_count);
> > +
> > + return status;
> > +}
> >
> > /* Generate the guest OS identifier as described in the Hyper-V TLFS */
> > static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
> > --
> > 2.17.1
> >
