x86: create ipi.c

This patch moves all ipi and apic related functions
from smp_32.c to ipi.c

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 178 insertions, 0 deletions

diff --git a/arch/x86/kernel/ipi.c b/arch/x86/kernel/ipi.c
new file mode 100644
index 000000000000..c0df7b89ca23
--- /dev/null
+++ b/arch/x86/kernel/ipi.c
@@ -0,0 +1,178 @@
+#include <linux/cpumask.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/kernel_stat.h>
+#include <linux/mc146818rtc.h>
+#include <linux/cache.h>
+#include <linux/interrupt.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
+
+#include <asm/smp.h>
+#include <asm/mtrr.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include <asm/apic.h>
+#include <asm/proto.h>
+
+#ifdef CONFIG_X86_32
+#include <mach_apic.h>
+/*
+ * the following functions deal with sending IPIs between CPUs.
+ *
+ * We use 'broadcast', CPU->CPU IPIs and self-IPIs too.
+ */
+
+static inline int __prepare_ICR(unsigned int shortcut, int vector)
+{
+        unsigned int icr = shortcut | APIC_DEST_LOGICAL;
+
+        switch (vector) {
+        default:
+                icr |= APIC_DM_FIXED | vector;
+                break;
+        case NMI_VECTOR:
+                icr |= APIC_DM_NMI;
+                break;
+        }
+        return icr;
+}
+
+static inline int __prepare_ICR2(unsigned int mask)
+{
+        return SET_APIC_DEST_FIELD(mask);
+}
+
+void __send_IPI_shortcut(unsigned int shortcut, int vector)
+{
+        /*
+         * Subtle. In the case of the 'never do double writes' workaround
+         * we have to lock out interrupts to be safe.  As we don't care
+         * of the value read we use an atomic rmw access to avoid costly
+         * cli/sti.  Otherwise we use an even cheaper single atomic write
+         * to the APIC.
+         */
+        unsigned int cfg;
+
+        /*
+         * Wait for idle.
+         */
+        apic_wait_icr_idle();
+
+        /*
+         * No need to touch the target chip field
+         */
+        cfg = __prepare_ICR(shortcut, vector);
+
+        /*
+         * Send the IPI. The write to APIC_ICR fires this off.
+         */
+        apic_write_around(APIC_ICR, cfg);
+}
+
+void send_IPI_self(int vector)
+{
+        __send_IPI_shortcut(APIC_DEST_SELF, vector);
+}
+
+/*
+ * This is used to send an IPI with no shorthand notation (the destination is
+ * specified in bits 56 to 63 of the ICR).
+ */
+static inline void __send_IPI_dest_field(unsigned long mask, int vector)
+{
+        unsigned long cfg;
+
+        /*
+         * Wait for idle.
+         */
+        if (unlikely(vector == NMI_VECTOR))
+                safe_apic_wait_icr_idle();
+        else
+                apic_wait_icr_idle();
+
+        /*
+         * prepare target chip field
+         */
+        cfg = __prepare_ICR2(mask);
+        apic_write_around(APIC_ICR2, cfg);
+
+        /*
+         * program the ICR
+         */
+        cfg = __prepare_ICR(0, vector);
+
+        /*
+         * Send the IPI. The write to APIC_ICR fires this off.
+         */
+        apic_write_around(APIC_ICR, cfg);
+}
+
+/*
+ * This is only used on smaller machines.
+ */
+void send_IPI_mask_bitmask(cpumask_t cpumask, int vector)
+{
+        unsigned long mask = cpus_addr(cpumask)[0];
+        unsigned long flags;
+
+        local_irq_save(flags);
+        WARN_ON(mask & ~cpus_addr(cpu_online_map)[0]);
+        __send_IPI_dest_field(mask, vector);
+        local_irq_restore(flags);
+}
+
+void send_IPI_mask_sequence(cpumask_t mask, int vector)
+{
+        unsigned long flags;
+        unsigned int query_cpu;
+
+        /*
+         * Hack. The clustered APIC addressing mode doesn't allow us to send
+         * to an arbitrary mask, so I do a unicasts to each CPU instead. This
+         * should be modified to do 1 message per cluster ID - mbligh
+         */
+
+        local_irq_save(flags);
+        for_each_possible_cpu(query_cpu) {
+                if (cpu_isset(query_cpu, mask)) {
+                        __send_IPI_dest_field(cpu_to_logical_apicid(query_cpu),
+                                              vector);
+                }
+        }
+        local_irq_restore(flags);
+}
+
+/* must come after the send_IPI functions above for inlining */
+#include <mach_ipi.h>
+static int convert_apicid_to_cpu(int apic_id)
+{
+        int i;
+
+        for_each_possible_cpu(i) {
+                if (per_cpu(x86_cpu_to_apicid, i) == apic_id)
+                        return i;
+        }
+        return -1;
+}
+
+int safe_smp_processor_id(void)
+{
+        int apicid, cpuid;
+
+        if (!boot_cpu_has(X86_FEATURE_APIC))
+                return 0;
+
+        apicid = hard_smp_processor_id();
+        if (apicid == BAD_APICID)
+                return 0;
+
+        cpuid = convert_apicid_to_cpu(apicid);
+
+        return cpuid >= 0 ? cpuid : 0;
+}
+#endif