[PATCH] powerpc: Move xics.[ch] into platforms/pseries

This patch moves the XICS interrupt controller code into the
platforms/pseries directory, since it only appears on pSeries
machines.  If it ever appears on some other machine we can move it to
sysdev, although xics.c itself will need a bunch of changes in that
case to remove pSeries specific assumptions.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

5 files changed, 784 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
index d5c160b789e..5ef494e3a70 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -2,3 +2,4 @@ obj-y			:= pci.o lpar.o hvCall.o nvram.o reconfig.o \
                            setup.o iommu.o rtas-fw.o ras.o
 obj-$(CONFIG_SMP)       += smp.o
 obj-$(CONFIG_IBMVIO)    += vio.o
+obj-$(CONFIG_XICS)      += xics.o
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 7e7e556e6b4..10cb0f2d9b5 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -59,7 +59,7 @@
 #include <asm/time.h>
 #include <asm/nvram.h>
 #include <asm/plpar_wrappers.h>
-#include <asm/xics.h>
+#include "xics.h"
 #include <asm/firmware.h>
 #include <asm/pmc.h>
 #include <asm/mpic.h>
diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c
index ae1bd270f30..9c9458ddfc2 100644
--- a/arch/powerpc/platforms/pseries/smp.c
+++ b/arch/powerpc/platforms/pseries/smp.c
@@ -39,7 +39,7 @@
 #include <asm/paca.h>
 #include <asm/time.h>
 #include <asm/machdep.h>
-#include <asm/xics.h>
+#include "xics.h"
 #include <asm/cputable.h>
 #include <asm/firmware.h>
 #include <asm/system.h>
diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c
new file mode 100644
index 00000000000..c72c86f05cb
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -0,0 +1,747 @@
+/*
+ * arch/powerpc/platforms/pseries/xics.c
+ *
+ * Copyright 2000 IBM Corporation.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ */
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/threads.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/signal.h>
+#include <linux/init.h>
+#include <linux/gfp.h>
+#include <linux/radix-tree.h>
+#include <linux/cpu.h>
+#include <asm/prom.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/smp.h>
+#include <asm/rtas.h>
+#include <asm/hvcall.h>
+#include <asm/machdep.h>
+#include <asm/i8259.h>
+
+#include "xics.h"
+
+static unsigned int xics_startup(unsigned int irq);
+static void xics_enable_irq(unsigned int irq);
+static void xics_disable_irq(unsigned int irq);
+static void xics_mask_and_ack_irq(unsigned int irq);
+static void xics_end_irq(unsigned int irq);
+static void xics_set_affinity(unsigned int irq_nr, cpumask_t cpumask);
+
+static struct hw_interrupt_type xics_pic = {
+        .typename = " XICS     ",
+        .startup = xics_startup,
+        .enable = xics_enable_irq,
+        .disable = xics_disable_irq,
+        .ack = xics_mask_and_ack_irq,
+        .end = xics_end_irq,
+        .set_affinity = xics_set_affinity
+};
+
+static struct hw_interrupt_type xics_8259_pic = {
+        .typename = " XICS/8259",
+        .ack = xics_mask_and_ack_irq,
+};
+
+/* This is used to map real irq numbers to virtual */
+static struct radix_tree_root irq_map = RADIX_TREE_INIT(GFP_ATOMIC);
+
+#define XICS_IPI                2
+#define XICS_IRQ_SPURIOUS       0
+
+/* Want a priority other than 0.  Various HW issues require this. */
+#define DEFAULT_PRIORITY        5
+
+/*
+ * Mark IPIs as higher priority so we can take them inside interrupts that
+ * arent marked SA_INTERRUPT
+ */
+#define IPI_PRIORITY            4
+
+struct xics_ipl {
+        union {
+                u32 word;
+                u8 bytes[4];
+        } xirr_poll;
+        union {
+                u32 word;
+                u8 bytes[4];
+        } xirr;
+        u32 dummy;
+        union {
+                u32 word;
+                u8 bytes[4];
+        } qirr;
+};
+
+static struct xics_ipl __iomem *xics_per_cpu[NR_CPUS];
+
+static int xics_irq_8259_cascade = 0;
+static int xics_irq_8259_cascade_real = 0;
+static unsigned int default_server = 0xFF;
+static unsigned int default_distrib_server = 0;
+static unsigned int interrupt_server_size = 8;
+
+/*
+ * XICS only has a single IPI, so encode the messages per CPU
+ */
+struct xics_ipi_struct xics_ipi_message[NR_CPUS] __cacheline_aligned;
+
+/* RTAS service tokens */
+static int ibm_get_xive;
+static int ibm_set_xive;
+static int ibm_int_on;
+static int ibm_int_off;
+
+typedef struct {
+        int (*xirr_info_get)(int cpu);
+        void (*xirr_info_set)(int cpu, int val);
+        void (*cppr_info)(int cpu, u8 val);
+        void (*qirr_info)(int cpu, u8 val);
+} xics_ops;
+
+
+/* SMP */
+
+static int pSeries_xirr_info_get(int n_cpu)
+{
+        return in_be32(&xics_per_cpu[n_cpu]->xirr.word);
+}
+
+static void pSeries_xirr_info_set(int n_cpu, int value)
+{
+        out_be32(&xics_per_cpu[n_cpu]->xirr.word, value);
+}
+
+static void pSeries_cppr_info(int n_cpu, u8 value)
+{
+        out_8(&xics_per_cpu[n_cpu]->xirr.bytes[0], value);
+}
+
+static void pSeries_qirr_info(int n_cpu, u8 value)
+{
+        out_8(&xics_per_cpu[n_cpu]->qirr.bytes[0], value);
+}
+
+static xics_ops pSeries_ops = {
+        pSeries_xirr_info_get,
+        pSeries_xirr_info_set,
+        pSeries_cppr_info,
+        pSeries_qirr_info
+};
+
+static xics_ops *ops = &pSeries_ops;
+
+
+/* LPAR */
+
+static inline long plpar_eoi(unsigned long xirr)
+{
+        return plpar_hcall_norets(H_EOI, xirr);
+}
+
+static inline long plpar_cppr(unsigned long cppr)
+{
+        return plpar_hcall_norets(H_CPPR, cppr);
+}
+
+static inline long plpar_ipi(unsigned long servernum, unsigned long mfrr)
+{
+        return plpar_hcall_norets(H_IPI, servernum, mfrr);
+}
+
+static inline long plpar_xirr(unsigned long *xirr_ret)
+{
+        unsigned long dummy;
+        return plpar_hcall(H_XIRR, 0, 0, 0, 0, xirr_ret, &dummy, &dummy);
+}
+
+static int pSeriesLP_xirr_info_get(int n_cpu)
+{
+        unsigned long lpar_rc;
+        unsigned long return_value;
+
+        lpar_rc = plpar_xirr(&return_value);
+        if (lpar_rc != H_Success)
+                panic(" bad return code xirr - rc = %lx \n", lpar_rc);
+        return (int)return_value;
+}
+
+static void pSeriesLP_xirr_info_set(int n_cpu, int value)
+{
+        unsigned long lpar_rc;
+        unsigned long val64 = value & 0xffffffff;
+
+        lpar_rc = plpar_eoi(val64);
+        if (lpar_rc != H_Success)
+                panic("bad return code EOI - rc = %ld, value=%lx\n", lpar_rc,
+                      val64);
+}
+
+void pSeriesLP_cppr_info(int n_cpu, u8 value)
+{
+        unsigned long lpar_rc;
+
+        lpar_rc = plpar_cppr(value);
+        if (lpar_rc != H_Success)
+                panic("bad return code cppr - rc = %lx\n", lpar_rc);
+}
+
+static void pSeriesLP_qirr_info(int n_cpu , u8 value)
+{
+        unsigned long lpar_rc;
+
+        lpar_rc = plpar_ipi(get_hard_smp_processor_id(n_cpu), value);
+        if (lpar_rc != H_Success)
+                panic("bad return code qirr - rc = %lx\n", lpar_rc);
+}
+
+xics_ops pSeriesLP_ops = {
+        pSeriesLP_xirr_info_get,
+        pSeriesLP_xirr_info_set,
+        pSeriesLP_cppr_info,
+        pSeriesLP_qirr_info
+};
+
+static unsigned int xics_startup(unsigned int virq)
+{
+        unsigned int irq;
+
+        irq = irq_offset_down(virq);
+        if (radix_tree_insert(&irq_map, virt_irq_to_real(irq),
+                              &virt_irq_to_real_map[irq]) == -ENOMEM)
+                printk(KERN_CRIT "Out of memory creating real -> virtual"
+                       " IRQ mapping for irq %u (real 0x%x)\n",
+                       virq, virt_irq_to_real(irq));
+        xics_enable_irq(virq);
+        return 0;       /* return value is ignored */
+}
+
+static unsigned int real_irq_to_virt(unsigned int real_irq)
+{
+        unsigned int *ptr;
+
+        ptr = radix_tree_lookup(&irq_map, real_irq);
+        if (ptr == NULL)
+                return NO_IRQ;
+        return ptr - virt_irq_to_real_map;
+}
+
+#ifdef CONFIG_SMP
+static int get_irq_server(unsigned int irq)
+{
+        unsigned int server;
+        /* For the moment only implement delivery to all cpus or one cpu */
+        cpumask_t cpumask = irq_affinity[irq];
+        cpumask_t tmp = CPU_MASK_NONE;
+
+        if (!distribute_irqs)
+                return default_server;
+
+        if (cpus_equal(cpumask, CPU_MASK_ALL)) {
+                server = default_distrib_server;
+        } else {
+                cpus_and(tmp, cpu_online_map, cpumask);
+
+                if (cpus_empty(tmp))
+                        server = default_distrib_server;
+                else
+                        server = get_hard_smp_processor_id(first_cpu(tmp));
+        }
+
+        return server;
+
+}
+#else
+static int get_irq_server(unsigned int irq)
+{
+        return default_server;
+}
+#endif
+
+static void xics_enable_irq(unsigned int virq)
+{
+        unsigned int irq;
+        int call_status;
+        unsigned int server;
+
+        irq = virt_irq_to_real(irq_offset_down(virq));
+        if (irq == XICS_IPI)
+                return;
+
+        server = get_irq_server(virq);
+        call_status = rtas_call(ibm_set_xive, 3, 1, NULL, irq, server,
+                                DEFAULT_PRIORITY);
+        if (call_status != 0) {
+                printk(KERN_ERR "xics_enable_irq: irq=%u: ibm_set_xive "
+                       "returned %d\n", irq, call_status);
+                printk("set_xive %x, server %x\n", ibm_set_xive, server);
+                return;
+        }
+
+        /* Now unmask the interrupt (often a no-op) */
+        call_status = rtas_call(ibm_int_on, 1, 1, NULL, irq);
+        if (call_status != 0) {
+                printk(KERN_ERR "xics_enable_irq: irq=%u: ibm_int_on "
+                       "returned %d\n", irq, call_status);
+                return;
+        }
+}
+
+static void xics_disable_real_irq(unsigned int irq)
+{
+        int call_status;
+        unsigned int server;
+
+        if (irq == XICS_IPI)
+                return;
+
+        call_status = rtas_call(ibm_int_off, 1, 1, NULL, irq);
+        if (call_status != 0) {
+                printk(KERN_ERR "xics_disable_real_irq: irq=%u: "
+                       "ibm_int_off returned %d\n", irq, call_status);
+                return;
+        }
+
+        server = get_irq_server(irq);
+        /* Have to set XIVE to 0xff to be able to remove a slot */
+        call_status = rtas_call(ibm_set_xive, 3, 1, NULL, irq, server, 0xff);
+        if (call_status != 0) {
+                printk(KERN_ERR "xics_disable_irq: irq=%u: ibm_set_xive(0xff)"
+                       " returned %d\n", irq, call_status);
+                return;
+        }
+}
+
+static void xics_disable_irq(unsigned int virq)
+{
+        unsigned int irq;
+
+        irq = virt_irq_to_real(irq_offset_down(virq));
+        xics_disable_real_irq(irq);
+}
+
+static void xics_end_irq(unsigned int irq)
+{
+        int cpu = smp_processor_id();
+
+        iosync();
+        ops->xirr_info_set(cpu, ((0xff << 24) |
+                                 (virt_irq_to_real(irq_offset_down(irq)))));
+
+}
+
+static void xics_mask_and_ack_irq(unsigned int irq)
+{
+        int cpu = smp_processor_id();
+
+        if (irq < irq_offset_value()) {
+                i8259_pic.ack(irq);
+                iosync();
+                ops->xirr_info_set(cpu, ((0xff<<24) |
+                                         xics_irq_8259_cascade_real));
+                iosync();
+        }
+}
+
+int xics_get_irq(struct pt_regs *regs)
+{
+        unsigned int cpu = smp_processor_id();
+        unsigned int vec;
+        int irq;
+
+        vec = ops->xirr_info_get(cpu);
+        /*  (vec >> 24) == old priority */
+        vec &= 0x00ffffff;
+
+        /* for sanity, this had better be < NR_IRQS - 16 */
+        if (vec == xics_irq_8259_cascade_real) {
+                irq = i8259_irq(regs);
+                if (irq == -1) {
+                        /* Spurious cascaded interrupt.  Still must ack xics */
+                        xics_end_irq(irq_offset_up(xics_irq_8259_cascade));
+
+                        irq = -1;
+                }
+        } else if (vec == XICS_IRQ_SPURIOUS) {
+                irq = -1;
+        } else {
+                irq = real_irq_to_virt(vec);
+                if (irq == NO_IRQ)
+                        irq = real_irq_to_virt_slowpath(vec);
+                if (irq == NO_IRQ) {
+                        printk(KERN_ERR "Interrupt %u (real) is invalid,"
+                               " disabling it.\n", vec);
+                        xics_disable_real_irq(vec);
+                } else
+                        irq = irq_offset_up(irq);
+        }
+        return irq;
+}
+
+#ifdef CONFIG_SMP
+
+irqreturn_t xics_ipi_action(int irq, void *dev_id, struct pt_regs *regs)
+{
+        int cpu = smp_processor_id();
+
+        ops->qirr_info(cpu, 0xff);
+
+        WARN_ON(cpu_is_offline(cpu));
+
+        while (xics_ipi_message[cpu].value) {
+                if (test_and_clear_bit(PPC_MSG_CALL_FUNCTION,
+                                       &xics_ipi_message[cpu].value)) {
+                        mb();
+                        smp_message_recv(PPC_MSG_CALL_FUNCTION, regs);
+                }
+                if (test_and_clear_bit(PPC_MSG_RESCHEDULE,
+                                       &xics_ipi_message[cpu].value)) {
+                        mb();
+                        smp_message_recv(PPC_MSG_RESCHEDULE, regs);
+                }
+#if 0
+                if (test_and_clear_bit(PPC_MSG_MIGRATE_TASK,
+                                       &xics_ipi_message[cpu].value)) {
+                        mb();
+                        smp_message_recv(PPC_MSG_MIGRATE_TASK, regs);
+                }
+#endif
+#ifdef CONFIG_DEBUGGER
+                if (test_and_clear_bit(PPC_MSG_DEBUGGER_BREAK,
+                                       &xics_ipi_message[cpu].value)) {
+                        mb();
+                        smp_message_recv(PPC_MSG_DEBUGGER_BREAK, regs);
+                }
+#endif
+        }
+        return IRQ_HANDLED;
+}
+
+void xics_cause_IPI(int cpu)
+{
+        ops->qirr_info(cpu, IPI_PRIORITY);
+}
+#endif /* CONFIG_SMP */
+
+void xics_setup_cpu(void)
+{
+        int cpu = smp_processor_id();
+
+        ops->cppr_info(cpu, 0xff);
+        iosync();
+
+        /*
+         * Put the calling processor into the GIQ.  This is really only
+         * necessary from a secondary thread as the OF start-cpu interface
+         * performs this function for us on primary threads.
+         *
+         * XXX: undo of teardown on kexec needs this too, as may hotplug
+         */
+        rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
+                (1UL << interrupt_server_size) - 1 - default_distrib_server, 1);
+}
+
+void xics_init_IRQ(void)
+{
+        int i;
+        unsigned long intr_size = 0;
+        struct device_node *np;
+        uint *ireg, ilen, indx = 0;
+        unsigned long intr_base = 0;
+        struct xics_interrupt_node {
+                unsigned long addr;
+                unsigned long size;
+        } intnodes[NR_CPUS];
+
+        ppc64_boot_msg(0x20, "XICS Init");
+
+        ibm_get_xive = rtas_token("ibm,get-xive");
+        ibm_set_xive = rtas_token("ibm,set-xive");
+        ibm_int_on  = rtas_token("ibm,int-on");
+        ibm_int_off = rtas_token("ibm,int-off");
+
+        np = of_find_node_by_type(NULL, "PowerPC-External-Interrupt-Presentation");
+        if (!np)
+                panic("xics_init_IRQ: can't find interrupt presentation");
+
+nextnode:
+        ireg = (uint *)get_property(np, "ibm,interrupt-server-ranges", NULL);
+        if (ireg) {
+                /*
+                 * set node starting index for this node
+                 */
+                indx = *ireg;
+        }
+
+        ireg = (uint *)get_property(np, "reg", &ilen);
+        if (!ireg)
+                panic("xics_init_IRQ: can't find interrupt reg property");
+
+        while (ilen) {
+                intnodes[indx].addr = (unsigned long)*ireg++ << 32;
+                ilen -= sizeof(uint);
+                intnodes[indx].addr |= *ireg++;
+                ilen -= sizeof(uint);
+                intnodes[indx].size = (unsigned long)*ireg++ << 32;
+                ilen -= sizeof(uint);
+                intnodes[indx].size |= *ireg++;
+                ilen -= sizeof(uint);
+                indx++;
+                if (indx >= NR_CPUS) break;
+        }
+
+        np = of_find_node_by_type(np, "PowerPC-External-Interrupt-Presentation");
+        if ((indx < NR_CPUS) && np) goto nextnode;
+
+        /* Find the server numbers for the boot cpu. */
+        for (np = of_find_node_by_type(NULL, "cpu");
+             np;
+             np = of_find_node_by_type(np, "cpu")) {
+                ireg = (uint *)get_property(np, "reg", &ilen);
+                if (ireg && ireg[0] == boot_cpuid_phys) {
+                        ireg = (uint *)get_property(np, "ibm,ppc-interrupt-gserver#s",
+                                                    &ilen);
+                        i = ilen / sizeof(int);
+                        if (ireg && i > 0) {
+                                default_server = ireg[0];
+                                default_distrib_server = ireg[i-1]; /* take last element */
+                        }
+                        ireg = (uint *)get_property(np,
+                                        "ibm,interrupt-server#-size", NULL);
+                        if (ireg)
+                                interrupt_server_size = *ireg;
+                        break;
+                }
+        }
+        of_node_put(np);
+
+        intr_base = intnodes[0].addr;
+        intr_size = intnodes[0].size;
+
+        np = of_find_node_by_type(NULL, "interrupt-controller");
+        if (!np) {
+                printk(KERN_WARNING "xics: no ISA interrupt controller\n");
+                xics_irq_8259_cascade_real = -1;
+                xics_irq_8259_cascade = -1;
+        } else {
+                ireg = (uint *) get_property(np, "interrupts", NULL);
+                if (!ireg)
+                        panic("xics_init_IRQ: can't find ISA interrupts property");
+
+                xics_irq_8259_cascade_real = *ireg;
+                xics_irq_8259_cascade
+                        = virt_irq_create_mapping(xics_irq_8259_cascade_real);
+                of_node_put(np);
+        }
+
+        if (systemcfg->platform == PLATFORM_PSERIES) {
+#ifdef CONFIG_SMP
+                for_each_cpu(i) {
+                        int hard_id;
+
+                        /* FIXME: Do this dynamically! --RR */
+                        if (!cpu_present(i))
+                                continue;
+
+                        hard_id = get_hard_smp_processor_id(i);
+                        xics_per_cpu[i] = ioremap(intnodes[hard_id].addr,
+                                                  intnodes[hard_id].size);
+                }
+#else
+                xics_per_cpu[0] = ioremap(intr_base, intr_size);
+#endif /* CONFIG_SMP */
+        } else if (systemcfg->platform == PLATFORM_PSERIES_LPAR) {
+                ops = &pSeriesLP_ops;
+        }
+
+        xics_8259_pic.enable = i8259_pic.enable;
+        xics_8259_pic.disable = i8259_pic.disable;
+        for (i = 0; i < 16; ++i)
+                get_irq_desc(i)->handler = &xics_8259_pic;
+        for (; i < NR_IRQS; ++i)
+                get_irq_desc(i)->handler = &xics_pic;
+
+        xics_setup_cpu();
+
+        ppc64_boot_msg(0x21, "XICS Done");
+}
+
+/*
+ * We cant do this in init_IRQ because we need the memory subsystem up for
+ * request_irq()
+ */
+static int __init xics_setup_i8259(void)
+{
+        if (ppc64_interrupt_controller == IC_PPC_XIC &&
+            xics_irq_8259_cascade != -1) {
+                if (request_irq(irq_offset_up(xics_irq_8259_cascade),
+                                no_action, 0, "8259 cascade", NULL))
+                        printk(KERN_ERR "xics_setup_i8259: couldn't get 8259 "
+                                        "cascade\n");
+                i8259_init(0, 0);
+        }
+        return 0;
+}
+arch_initcall(xics_setup_i8259);
+
+#ifdef CONFIG_SMP
+void xics_request_IPIs(void)
+{
+        virt_irq_to_real_map[XICS_IPI] = XICS_IPI;
+
+        /* IPIs are marked SA_INTERRUPT as they must run with irqs disabled */
+        request_irq(irq_offset_up(XICS_IPI), xics_ipi_action, SA_INTERRUPT,
+                    "IPI", NULL);
+        get_irq_desc(irq_offset_up(XICS_IPI))->status |= IRQ_PER_CPU;
+}
+#endif
+
+static void xics_set_affinity(unsigned int virq, cpumask_t cpumask)
+{
+        unsigned int irq;
+        int status;
+        int xics_status[2];
+        unsigned long newmask;
+        cpumask_t tmp = CPU_MASK_NONE;
+
+        irq = virt_irq_to_real(irq_offset_down(virq));
+        if (irq == XICS_IPI || irq == NO_IRQ)
+                return;
+
+        status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
+
+        if (status) {
+                printk(KERN_ERR "xics_set_affinity: irq=%u ibm,get-xive "
+                       "returns %d\n", irq, status);
+                return;
+        }
+
+        /* For the moment only implement delivery to all cpus or one cpu */
+        if (cpus_equal(cpumask, CPU_MASK_ALL)) {
+                newmask = default_distrib_server;
+        } else {
+                cpus_and(tmp, cpu_online_map, cpumask);
+                if (cpus_empty(tmp))
+                        return;
+                newmask = get_hard_smp_processor_id(first_cpu(tmp));
+        }
+
+        status = rtas_call(ibm_set_xive, 3, 1, NULL,
+                                irq, newmask, xics_status[1]);
+
+        if (status) {
+                printk(KERN_ERR "xics_set_affinity: irq=%u ibm,set-xive "
+                       "returns %d\n", irq, status);
+                return;
+        }
+}
+
+void xics_teardown_cpu(int secondary)
+{
+        int cpu = smp_processor_id();
+
+        ops->cppr_info(cpu, 0x00);
+        iosync();
+
+        /*
+         * Some machines need to have at least one cpu in the GIQ,
+         * so leave the master cpu in the group.
+         */
+        if (secondary) {
+                /*
+                 * we need to EOI the IPI if we got here from kexec down IPI
+                 *
+                 * probably need to check all the other interrupts too
+                 * should we be flagging idle loop instead?
+                 * or creating some task to be scheduled?
+                 */
+                ops->xirr_info_set(cpu, XICS_IPI);
+                rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
+                        (1UL << interrupt_server_size) - 1 -
+                        default_distrib_server, 0);
+        }
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/* Interrupts are disabled. */
+void xics_migrate_irqs_away(void)
+{
+        int status;
+        unsigned int irq, virq, cpu = smp_processor_id();
+
+        /* Reject any interrupt that was queued to us... */
+        ops->cppr_info(cpu, 0);
+        iosync();
+
+        /* remove ourselves from the global interrupt queue */
+        status = rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
+                (1UL << interrupt_server_size) - 1 - default_distrib_server, 0);
+        WARN_ON(status < 0);
+
+        /* Allow IPIs again... */
+        ops->cppr_info(cpu, DEFAULT_PRIORITY);
+        iosync();
+
+        for_each_irq(virq) {
+                irq_desc_t *desc;
+                int xics_status[2];
+                unsigned long flags;
+
+                /* We cant set affinity on ISA interrupts */
+                if (virq < irq_offset_value())
+                        continue;
+
+                desc = get_irq_desc(virq);
+                irq = virt_irq_to_real(irq_offset_down(virq));
+
+                /* We need to get IPIs still. */
+                if (irq == XICS_IPI || irq == NO_IRQ)
+                        continue;
+
+                /* We only need to migrate enabled IRQS */
+                if (desc == NULL || desc->handler == NULL
+                    || desc->action == NULL
+                    || desc->handler->set_affinity == NULL)
+                        continue;
+
+                spin_lock_irqsave(&desc->lock, flags);
+
+                status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
+                if (status) {
+                        printk(KERN_ERR "migrate_irqs_away: irq=%u "
+                                        "ibm,get-xive returns %d\n",
+                                        virq, status);
+                        goto unlock;
+                }
+
+                /*
+                 * We only support delivery to all cpus or to one cpu.
+                 * The irq has to be migrated only in the single cpu
+                 * case.
+                 */
+                if (xics_status[0] != get_hard_smp_processor_id(cpu))
+                        goto unlock;
+
+                printk(KERN_WARNING "IRQ %u affinity broken off cpu %u\n",
+                       virq, cpu);
+
+                /* Reset affinity to all cpus */
+                desc->handler->set_affinity(virq, CPU_MASK_ALL);
+                irq_affinity[virq] = CPU_MASK_ALL;
+unlock:
+                spin_unlock_irqrestore(&desc->lock, flags);
+        }
+}
+#endif
diff --git a/arch/powerpc/platforms/pseries/xics.h b/arch/powerpc/platforms/pseries/xics.h
new file mode 100644
index 00000000000..e14c70868f1
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/xics.h
@@ -0,0 +1,34 @@
+/*
+ * arch/powerpc/platforms/pseries/xics.h
+ *
+ * Copyright 2000 IBM Corporation.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _POWERPC_KERNEL_XICS_H
+#define _POWERPC_KERNEL_XICS_H
+
+#include <linux/cache.h>
+
+void xics_init_IRQ(void);
+int xics_get_irq(struct pt_regs *);
+void xics_setup_cpu(void);
+void xics_teardown_cpu(int secondary);
+void xics_cause_IPI(int cpu);
+void xics_request_IPIs(void);
+void xics_migrate_irqs_away(void);
+
+/* first argument is ignored for now*/
+void pSeriesLP_cppr_info(int n_cpu, u8 value);
+
+struct xics_ipi_struct {
+        volatile unsigned long value;
+} ____cacheline_aligned;
+
+extern struct xics_ipi_struct xics_ipi_message[NR_CPUS] __cacheline_aligned;
+
+#endif /* _POWERPC_KERNEL_XICS_H */