[IA64] Implement smp_call_function_mask for ia64

This interface provides more flexible functionality for smp
infrastructure ... e.g. KVM frequently needs to operate on
a subset of cpus.

Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c
index 4e446aa5f4ac98c0011552a68db633fcb68a3324..9a9d4c4893305848dc91ded242577d55ff3ef13a 100644 (file)
--- a/arch/ia64/kernel/smp.c
+++ b/arch/ia64/kernel/smp.c
@@ -209,6 +209,19 @@ send_IPI_allbutself (int op)
        }
 }
 
+/*
+ * Called with preemption disabled.
+ */
+static inline void
+send_IPI_mask(cpumask_t mask, int op)
+{
+       unsigned int cpu;
+
+       for_each_cpu_mask(cpu, mask) {
+                       send_IPI_single(cpu, op);
+       }
+}
+
 /*
  * Called with preemption disabled.
  */
@@ -401,6 +414,75 @@ smp_call_function_single (int cpuid, void (*func) (void *info), void *info, int
 }
 EXPORT_SYMBOL(smp_call_function_single);
 
+/**
+ * smp_call_function_mask(): Run a function on a set of other CPUs.
+ * <mask>      The set of cpus to run on.  Must not include the current cpu.
+ * <func>      The function to run. This must be fast and non-blocking.
+ * <info>      An arbitrary pointer to pass to the function.
+ * <wait>      If true, wait (atomically) until function
+ *             has completed on other CPUs.
+ *
+ * Returns 0 on success, else a negative status code.
+ *
+ * If @wait is true, then returns once @func has returned; otherwise
+ * it returns just before the target cpu calls @func.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.
+ */
+int smp_call_function_mask(cpumask_t mask,
+                          void (*func)(void *), void *info,
+                          int wait)
+{
+       struct call_data_struct data;
+       cpumask_t allbutself;
+       int cpus;
+
+       spin_lock(&call_lock);
+       allbutself = cpu_online_map;
+       cpu_clear(smp_processor_id(), allbutself);
+
+       cpus_and(mask, mask, allbutself);
+       cpus = cpus_weight(mask);
+       if (!cpus) {
+               spin_unlock(&call_lock);
+               return 0;
+       }
+
+       /* Can deadlock when called with interrupts disabled */
+       WARN_ON(irqs_disabled());
+
+       data.func = func;
+       data.info = info;
+       atomic_set(&data.started, 0);
+       data.wait = wait;
+       if (wait)
+               atomic_set(&data.finished, 0);
+
+       call_data = &data;
+       mb(); /* ensure store to call_data precedes setting of IPI_CALL_FUNC*/
+
+       /* Send a message to other CPUs */
+       if (cpus_equal(mask, allbutself))
+               send_IPI_allbutself(IPI_CALL_FUNC);
+       else
+               send_IPI_mask(mask, IPI_CALL_FUNC);
+
+       /* Wait for response */
+       while (atomic_read(&data.started) != cpus)
+               cpu_relax();
+
+       if (wait)
+               while (atomic_read(&data.finished) != cpus)
+                       cpu_relax();
+       call_data = NULL;
+
+       spin_unlock(&call_lock);
+       return 0;
+
+}
+EXPORT_SYMBOL(smp_call_function_mask);
+
 /*
  * this function sends a 'generic call function' IPI to all other CPUs
  * in the system.

diff --git a/include/asm-ia64/smp.h b/include/asm-ia64/smp.h
index 4fa733dd417a4102ae7409661f9312a4b431ec9c..ec5f355fb7e36561d6815cac2149bca9e72b5911 100644 (file)
--- a/include/asm-ia64/smp.h
+++ b/include/asm-ia64/smp.h
@@ -38,6 +38,9 @@ ia64_get_lid (void)
        return lid.f.id << 8 | lid.f.eid;
 }
 
+extern int smp_call_function_mask(cpumask_t mask, void (*func)(void *),
+                                 void *info, int wait);
+
 #define hard_smp_processor_id()                ia64_get_lid()
 
 #ifdef CONFIG_SMP