x64, x2apic/intr-remap: x2apic cluster mode support

x2apic cluster mode support.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 135 insertions, 0 deletions

diff --git a/arch/x86/kernel/genx2apic_cluster.c b/arch/x86/kernel/genx2apic_cluster.c
new file mode 100644
index 000000000000..ed0fdede800a
--- /dev/null
+++ b/arch/x86/kernel/genx2apic_cluster.c
@@ -0,0 +1,135 @@
+#include <linux/threads.h>
+#include <linux/cpumask.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/init.h>
+#include <asm/smp.h>
+#include <asm/ipi.h>
+#include <asm/genapic.h>
+
+DEFINE_PER_CPU(u32, x86_cpu_to_logical_apicid);
+
+/* Start with all IRQs pointing to boot CPU.  IRQ balancing will shift them. */
+
+static cpumask_t x2apic_target_cpus(void)
+{
+        return cpumask_of_cpu(0);
+}
+
+/*
+ * for now each logical cpu is in its own vector allocation domain.
+ */
+static cpumask_t x2apic_vector_allocation_domain(int cpu)
+{
+        cpumask_t domain = CPU_MASK_NONE;
+        cpu_set(cpu, domain);
+        return domain;
+}
+
+static void __x2apic_send_IPI_dest(unsigned int apicid, int vector,
+                                   unsigned int dest)
+{
+        unsigned long cfg;
+
+        cfg = __prepare_ICR(0, vector, dest);
+
+        /*
+         * send the IPI.
+         */
+        x2apic_icr_write(cfg, apicid);
+}
+
+/*
+ * for now, we send the IPI's one by one in the cpumask.
+ * TBD: Based on the cpu mask, we can send the IPI's to the cluster group
+ * at once. We have 16 cpu's in a cluster. This will minimize IPI register
+ * writes.
+ */
+static void x2apic_send_IPI_mask(cpumask_t mask, int vector)
+{
+        unsigned long flags;
+        unsigned long query_cpu;
+
+        local_irq_save(flags);
+        for_each_cpu_mask(query_cpu, mask) {
+                __x2apic_send_IPI_dest(per_cpu(x86_cpu_to_logical_apicid, query_cpu),
+                                       vector, APIC_DEST_LOGICAL);
+        }
+        local_irq_restore(flags);
+}
+
+static void x2apic_send_IPI_allbutself(int vector)
+{
+        cpumask_t mask = cpu_online_map;
+
+        cpu_clear(smp_processor_id(), mask);
+
+        if (!cpus_empty(mask))
+                x2apic_send_IPI_mask(mask, vector);
+}
+
+static void x2apic_send_IPI_all(int vector)
+{
+        x2apic_send_IPI_mask(cpu_online_map, vector);
+}
+
+static int x2apic_apic_id_registered(void)
+{
+        return 1;
+}
+
+static unsigned int x2apic_cpu_mask_to_apicid(cpumask_t cpumask)
+{
+        int cpu;
+
+        /*
+         * We're using fixed IRQ delivery, can only return one phys APIC ID.
+         * May as well be the first.
+         */
+        cpu = first_cpu(cpumask);
+        if ((unsigned)cpu < NR_CPUS)
+                return per_cpu(x86_cpu_to_logical_apicid, cpu);
+        else
+                return BAD_APICID;
+}
+
+static unsigned int x2apic_read_id(void)
+{
+        return apic_read(APIC_ID);
+}
+
+static unsigned int phys_pkg_id(int index_msb)
+{
+        return x2apic_read_id() >> index_msb;
+}
+
+static void x2apic_send_IPI_self(int vector)
+{
+        apic_write(APIC_SELF_IPI, vector);
+}
+
+static void init_x2apic_ldr(void)
+{
+        int cpu = smp_processor_id();
+
+        per_cpu(x86_cpu_to_logical_apicid, cpu) = apic_read(APIC_LDR);
+        return;
+}
+
+struct genapic apic_x2apic_cluster = {
+        .name = "cluster x2apic",
+        .int_delivery_mode = dest_LowestPrio,
+        .int_dest_mode = (APIC_DEST_LOGICAL != 0),
+        .target_cpus = x2apic_target_cpus,
+        .vector_allocation_domain = x2apic_vector_allocation_domain,
+        .apic_id_registered = x2apic_apic_id_registered,
+        .init_apic_ldr = init_x2apic_ldr,
+        .send_IPI_all = x2apic_send_IPI_all,
+        .send_IPI_allbutself = x2apic_send_IPI_allbutself,
+        .send_IPI_mask = x2apic_send_IPI_mask,
+        .send_IPI_self = x2apic_send_IPI_self,
+        .cpu_mask_to_apicid = x2apic_cpu_mask_to_apicid,
+        .phys_pkg_id = phys_pkg_id,
+        .read_apic_id = x2apic_read_id,
+};