[ACPI] Evaluate CPEI Processor Override flag

ACPI 3.0 added a Correctable Platform Error Interrupt (CPEI)
Processor Overide flag to MADT.Platform_Interrupt_Source.
Record the processor that was provided as hint from ACPI.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

arch/ia64/kernel/acpi.c

@@ -11,6 +11,7 @@
  *  Copyright (C) 2001 Jenna Hall <jenna.s.hall@intel.com>
  *  Copyright (C) 2001 Takayoshi Kochi <t-kochi@bq.jp.nec.com>
  *  Copyright (C) 2002 Erich Focht <efocht@ess.nec.de>
+ *  Copyright (C) 2004 Ashok Raj <ashok.raj@intel.com>
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
@@ -67,6 +68,11 @@ EXPORT_SYMBOL(pm_power_off);
 unsigned char acpi_kbd_controller_present = 1;
 unsigned char acpi_legacy_devices;
 
+static unsigned int __initdata acpi_madt_rev;
+
+unsigned int acpi_cpei_override;
+unsigned int acpi_cpei_phys_cpuid;
+
 #define MAX_SAPICS 256
 u16 ia64_acpiid_to_sapicid[MAX_SAPICS] =
 	{ [0 ... MAX_SAPICS - 1] = -1 };
@@ -267,10 +273,56 @@ acpi_parse_plat_int_src (
 						(plintsrc->flags.trigger == 1) ? IOSAPIC_EDGE : IOSAPIC_LEVEL);
 
 	platform_intr_list[plintsrc->type] = vector;
+	if (acpi_madt_rev > 1) {
+		acpi_cpei_override = plintsrc->plint_flags.cpei_override_flag;
+	}
+
+	/*
+	 * Save the physical id, so we can check when its being removed
+	 */
+	acpi_cpei_phys_cpuid = ((plintsrc->id << 8) | (plintsrc->eid)) & 0xffff;
+
 	return 0;
 }
 
 
+unsigned int can_cpei_retarget(void)
+{
+	extern int cpe_vector;
+
+	/*
+	 * Only if CPEI is supported and the override flag
+	 * is present, otherwise return that its re-targettable
+	 * if we are in polling mode.
+	 */
+	if (cpe_vector > 0 && !acpi_cpei_override)
+		return 0;
+	else
+		return 1;
+}
+
+unsigned int is_cpu_cpei_target(unsigned int cpu)
+{
+	unsigned int logical_id;
+
+	logical_id = cpu_logical_id(acpi_cpei_phys_cpuid);
+
+	if (logical_id == cpu)
+		return 1;
+	else
+		return 0;
+}
+
+void set_cpei_target_cpu(unsigned int cpu)
+{
+	acpi_cpei_phys_cpuid = cpu_physical_id(cpu);
+}
+
+unsigned int get_cpei_target_cpu(void)
+{
+	return acpi_cpei_phys_cpuid;
+}
+
 static int __init
 acpi_parse_int_src_ovr (
 	acpi_table_entry_header *header, const unsigned long end)
@@ -328,6 +380,8 @@ acpi_parse_madt (unsigned long phys_addr, unsigned long size)
 
 	acpi_madt = (struct acpi_table_madt *) __va(phys_addr);
 
+	acpi_madt_rev = acpi_madt->header.revision;
+
 	/* remember the value for reference after free_initmem() */
 #ifdef CONFIG_ITANIUM
 	has_8259 = 1; /* Firmware on old Itanium systems is broken */

arch/ia64/kernel/mca.c

@@ -271,7 +271,7 @@ ia64_mca_log_sal_error_record(int sal_info_type)
 
 #ifdef CONFIG_ACPI
 
-static int cpe_vector = -1;
+int cpe_vector = -1;
 
 static irqreturn_t
 ia64_mca_cpe_int_handler (int cpe_irq, void *arg, struct pt_regs *ptregs)

arch/ia64/kernel/topology.c

@@ -36,6 +36,13 @@ int arch_register_cpu(int num)
 	parent = &sysfs_nodes[cpu_to_node(num)];
 #endif /* CONFIG_NUMA */
 
+	/*
+	 * If CPEI cannot be re-targetted, and this is
+	 * CPEI target, then dont create the control file
+	 */
+	if (!can_cpei_retarget() && is_cpu_cpei_target(num))
+		sysfs_cpus[num].cpu.no_control = 1;
+
 	return register_cpu(&sysfs_cpus[num].cpu, num, parent);
 }
 

include/asm-ia64/acpi.h

@@ -98,6 +98,15 @@ const char *acpi_get_sysname (void);
 int acpi_request_vector (u32 int_type);
 int acpi_gsi_to_irq (u32 gsi, unsigned int *irq);
 
+/*
+ * Record the cpei override flag and current logical cpu. This is
+ * useful for CPU removal.
+ */
+extern unsigned int can_cpei_retarget(void);
+extern unsigned int is_cpu_cpei_target(unsigned int cpu);
+extern void set_cpei_target_cpu(unsigned int cpu);
+extern unsigned int get_cpei_target_cpu(void);
+
 #ifdef CONFIG_ACPI_NUMA
 /* Proximity bitmap length; _PXM is at most 255 (8 bit)*/
 #define MAX_PXM_DOMAINS (256)

include/linux/acpi.h

@@ -206,7 +206,10 @@ struct acpi_table_plat_int_src {
 	u8			eid;
 	u8			iosapic_vector;
 	u32			global_irq;
-	u32			reserved;
+	struct {
+		u32			cpei_override_flag:1;
+		u32			reserved:31;
+	}			plint_flags;
 } __attribute__ ((packed));
 
 enum acpi_interrupt_id {