asm-generic/hyperv: provide cpumask_to_vpset_noself

This is a new variant which removes `self' cpu from the vpset. It will
be used in Hyper-V enlightened IPI code.

Signed-off-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210910185714.299411-2-wei.liu@kernel.org

diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 9a000ba..9a13480 100644 (file)
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -184,10 +184,12 @@ static inline int hv_cpu_number_to_vp_number(int cpu_number)
        return hv_vp_index[cpu_number];
 }
 
-static inline int cpumask_to_vpset(struct hv_vpset *vpset,
-                                   const struct cpumask *cpus)
+static inline int __cpumask_to_vpset(struct hv_vpset *vpset,
+                                   const struct cpumask *cpus,
+                                   bool exclude_self)
 {
        int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
+       int this_cpu = smp_processor_id();
 
        /* valid_bank_mask can represent up to 64 banks */
        if (hv_max_vp_index / 64 >= 64)
@@ -205,6 +207,8 @@ static inline int cpumask_to_vpset(struct hv_vpset *vpset,
         * Some banks may end up being empty but this is acceptable.
         */
        for_each_cpu(cpu, cpus) {
+               if (exclude_self && cpu == this_cpu)
+                       continue;
                vcpu = hv_cpu_number_to_vp_number(cpu);
                if (vcpu == VP_INVAL)
                        return -1;
@@ -219,6 +223,19 @@ static inline int cpumask_to_vpset(struct hv_vpset *vpset,
        return nr_bank;
 }
 
+static inline int cpumask_to_vpset(struct hv_vpset *vpset,
+                                   const struct cpumask *cpus)
+{
+       return __cpumask_to_vpset(vpset, cpus, false);
+}
+
+static inline int cpumask_to_vpset_noself(struct hv_vpset *vpset,
+                                   const struct cpumask *cpus)
+{
+       WARN_ON_ONCE(preemptible());
+       return __cpumask_to_vpset(vpset, cpus, true);
+}
+
 void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die);
 bool hv_is_hyperv_initialized(void);
 bool hv_is_hibernation_supported(void);