[patch 25/26] x64, x2apic/intr-remap: support for x2apic physical mode support

From: Suresh Siddha
Date: Thu Jul 10 2008 - 14:46:32 EST


x2apic Physical mode support. By default we will use x2apic cluster mode.
x2apic physical mode can be selected using "x2apic_phys" boot parameter.

Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
---

Index: tree-x86/arch/x86/kernel/Makefile
===================================================================
--- tree-x86.orig/arch/x86/kernel/Makefile 2008-07-10 09:52:27.000000000 -0700
+++ tree-x86/arch/x86/kernel/Makefile 2008-07-10 09:52:40.000000000 -0700
@@ -105,6 +105,7 @@
ifeq ($(CONFIG_X86_64),y)
obj-y += genapic_64.o genapic_flat_64.o genx2apic_uv_x.o tlb_uv.o
obj-y += genx2apic_cluster.o
+ obj-y += genx2apic_phys.o
obj-$(CONFIG_X86_PM_TIMER) += pmtimer_64.o
obj-$(CONFIG_AUDIT) += audit_64.o

Index: tree-x86/include/asm-x86/genapic_64.h
===================================================================
--- tree-x86.orig/include/asm-x86/genapic_64.h 2008-07-10 09:52:27.000000000 -0700
+++ tree-x86/include/asm-x86/genapic_64.h 2008-07-10 09:52:40.000000000 -0700
@@ -36,6 +36,7 @@
extern struct genapic apic_flat;
extern struct genapic apic_physflat;
extern struct genapic apic_x2apic_cluster;
+extern struct genapic apic_x2apic_phys;
extern int acpi_madt_oem_check(char *, char *);

extern void apic_send_IPI_self(int vector);
Index: tree-x86/arch/x86/kernel/genx2apic_phys.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ tree-x86/arch/x86/kernel/genx2apic_phys.c 2008-07-10 09:52:40.000000000 -0700
@@ -0,0 +1,122 @@
+#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>
+
+
+/* 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);
+}
+
+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);
+}
+
+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_apicid, query_cpu),
+ vector, APIC_DEST_PHYSICAL);
+ }
+ 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_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;
+}
+
+void x2apic_send_IPI_self(int vector)
+{
+ apic_write(APIC_SELF_IPI, vector);
+}
+
+void init_x2apic_ldr(void)
+{
+ return;
+}
+
+struct genapic apic_x2apic_phys = {
+ .name = "physical x2apic",
+ .int_delivery_mode = dest_Fixed,
+ .int_dest_mode = (APIC_DEST_PHYSICAL != 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,
+};
Index: tree-x86/arch/x86/kernel/genapic_64.c
===================================================================
--- tree-x86.orig/arch/x86/kernel/genapic_64.c 2008-07-10 09:52:36.000000000 -0700
+++ tree-x86/arch/x86/kernel/genapic_64.c 2008-07-10 09:52:40.000000000 -0700
@@ -30,6 +30,15 @@

struct genapic __read_mostly *genapic = &apic_flat;

+static int x2apic_phys = 0;
+
+static int set_x2apic_phys_mode(char *arg)
+{
+ x2apic_phys = 1;
+ return 0;
+}
+early_param("x2apic_phys", set_x2apic_phys_mode);
+
static enum uv_system_type uv_system_type;

/*
@@ -39,9 +48,12 @@
{
if (uv_system_type == UV_NON_UNIQUE_APIC)
genapic = &apic_x2apic_uv_x;
- else if (cpu_has_x2apic && intr_remapping_enabled)
- genapic = &apic_x2apic_cluster;
- else
+ else if (cpu_has_x2apic && intr_remapping_enabled) {
+ if (x2apic_phys)
+ genapic = &apic_x2apic_phys;
+ else
+ genapic = &apic_x2apic_cluster;
+ } else
#ifdef CONFIG_ACPI
/*
* Quirk: some x86_64 machines can only use physical APIC mode

--

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