x86: Add cpu_mask_to_apicid_and

Impact: new API

Add a helper function that takes two cpumask's, and's them and then
returns the apicid of the result.  This removes a need in io_apic.c
that uses a temporary cpumask to hold (mask & cfg->domain).

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 16 insertions, 0 deletions

diff --git a/arch/x86/kernel/genx2apic_phys.c b/arch/x86/kernel/genx2apic_phys.c
index 41c27b2f3d01..d5578bb8f165 100644
--- a/arch/x86/kernel/genx2apic_phys.c
+++ b/arch/x86/kernel/genx2apic_phys.c
@@ -122,6 +122,21 @@ static unsigned int x2apic_cpu_mask_to_apicid(const cpumask_t *cpumask)
                 return BAD_APICID;
 }
 
+static unsigned int x2apic_cpu_mask_to_apicid_and(const cpumask_t *cpumask,
+                                                  const cpumask_t *andmask)
+{
+        int cpu;
+
+        /*
+         * We're using fixed IRQ delivery, can only return one phys APIC ID.
+         * May as well be the first.
+         */
+        while ((cpu = next_cpu(-1, *cpumask)) < nr_cpu_ids)
+                if (cpu_isset(cpu, *andmask))
+                        return per_cpu(x86_cpu_to_apicid, cpu);
+        return BAD_APICID;
+}
+
 static unsigned int get_apic_id(unsigned long x)
 {
         unsigned int id;
@@ -168,6 +183,7 @@ struct genapic apic_x2apic_phys = {
         .send_IPI_mask_allbutself = x2apic_send_IPI_mask_allbutself,
         .send_IPI_self = x2apic_send_IPI_self,
         .cpu_mask_to_apicid = x2apic_cpu_mask_to_apicid,
+        .cpu_mask_to_apicid_and = x2apic_cpu_mask_to_apicid_and,
         .phys_pkg_id = phys_pkg_id,
         .get_apic_id = get_apic_id,
         .set_apic_id = set_apic_id,