5 files changed, 496 insertions, 351 deletions

diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index 9639c66b453d..9df783088b61 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -72,32 +72,62 @@ static irqreturn_t ras_error_interrupt(int irq, void *dev_id,
 
 /* #define DEBUG */
 
-static void request_ras_irqs(struct device_node *np, char *propname,
+
+static void request_ras_irqs(struct device_node *np,
                         irqreturn_t (*handler)(int, void *, struct pt_regs *),
                         const char *name)
 {
-        unsigned int *ireg, len, i;
-        int virq, n_intr;
-
-        ireg = (unsigned int *)get_property(np, propname, &len);
-        if (ireg == NULL)
-                return;
-        n_intr = prom_n_intr_cells(np);
-        len /= n_intr * sizeof(*ireg);
-
-        for (i = 0; i < len; i++) {
-                virq = virt_irq_create_mapping(*ireg);
-                if (virq == NO_IRQ) {
-                        printk(KERN_ERR "Unable to allocate interrupt "
-                               "number for %s\n", np->full_name);
-                        return;
+        int i, index, count = 0;
+        struct of_irq oirq;
+        u32 *opicprop;
+        unsigned int opicplen;
+        unsigned int virqs[16];
+
+        /* Check for obsolete "open-pic-interrupt" property. If present, then
+         * map those interrupts using the default interrupt host and default
+         * trigger
+         */
+        opicprop = (u32 *)get_property(np, "open-pic-interrupt", &opicplen);
+        if (opicprop) {
+                opicplen /= sizeof(u32);
+                for (i = 0; i < opicplen; i++) {
+                        if (count > 15)
+                                break;
+                        virqs[count] = irq_create_mapping(NULL, *(opicprop++),
+                                                         IRQ_TYPE_NONE);
+                        if (virqs[count] == NO_IRQ)
+                                printk(KERN_ERR "Unable to allocate interrupt "
+                                       "number for %s\n", np->full_name);
+                        else
+                                count++;
+
                 }
-                if (request_irq(irq_offset_up(virq), handler, 0, name, NULL)) {
+        }
+        /* Else use normal interrupt tree parsing */
+        else {
+                /* First try to do a proper OF tree parsing */
+                for (index = 0; of_irq_map_one(np, index, &oirq) == 0;
+                     index++) {
+                        if (count > 15)
+                                break;
+                        virqs[count] = irq_create_of_mapping(oirq.controller,
+                                                            oirq.specifier,
+                                                            oirq.size);
+                        if (virqs[count] == NO_IRQ)
+                                printk(KERN_ERR "Unable to allocate interrupt "
+                                       "number for %s\n", np->full_name);
+                        else
+                                count++;
+                }
+        }
+
+        /* Now request them */
+        for (i = 0; i < count; i++) {
+                if (request_irq(virqs[i], handler, 0, name, NULL)) {
                         printk(KERN_ERR "Unable to request interrupt %d for "
-                               "%s\n", irq_offset_up(virq), np->full_name);
+                               "%s\n", virqs[i], np->full_name);
                         return;
                 }
-                ireg += n_intr;
         }
 }
 
@@ -115,20 +145,14 @@ static int __init init_ras_IRQ(void)
         /* Internal Errors */
         np = of_find_node_by_path("/event-sources/internal-errors");
         if (np != NULL) {
-                request_ras_irqs(np, "open-pic-interrupt", ras_error_interrupt,
-                                 "RAS_ERROR");
-                request_ras_irqs(np, "interrupts", ras_error_interrupt,
-                                 "RAS_ERROR");
+                request_ras_irqs(np, ras_error_interrupt, "RAS_ERROR");
                 of_node_put(np);
         }
 
         /* EPOW Events */
         np = of_find_node_by_path("/event-sources/epow-events");
         if (np != NULL) {
-                request_ras_irqs(np, "open-pic-interrupt", ras_epow_interrupt,
-                                 "RAS_EPOW");
-                request_ras_irqs(np, "interrupts", ras_epow_interrupt,
-                                 "RAS_EPOW");
+                request_ras_irqs(np, ras_epow_interrupt, "RAS_EPOW");
                 of_node_put(np);
         }
 
@@ -162,7 +186,7 @@ ras_epow_interrupt(int irq, void *dev_id, struct pt_regs * regs)
 
         status = rtas_call(ras_check_exception_token, 6, 1, NULL,
                            RAS_VECTOR_OFFSET,
-                           virt_irq_to_real(irq_offset_down(irq)),
+                           irq_map[irq].hwirq,
                            RTAS_EPOW_WARNING | RTAS_POWERMGM_EVENTS,
                            critical, __pa(&ras_log_buf),
                                 rtas_get_error_log_max());
@@ -198,7 +222,7 @@ ras_error_interrupt(int irq, void *dev_id, struct pt_regs * regs)
 
         status = rtas_call(ras_check_exception_token, 6, 1, NULL,
                            RAS_VECTOR_OFFSET,
-                           virt_irq_to_real(irq_offset_down(irq)),
+                           irq_map[irq].hwirq,
                            RTAS_INTERNAL_ERROR, 1 /*Time Critical */,
                            __pa(&ras_log_buf),
                                 rtas_get_error_log_max());
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 476b564a208b..54a52437265c 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -76,6 +76,9 @@
 #define DBG(fmt...)
 #endif
 
+/* move those away to a .h */
+extern void smp_init_pseries_mpic(void);
+extern void smp_init_pseries_xics(void);
 extern void find_udbg_vterm(void);
 
 int fwnmi_active;  /* TRUE if an FWNMI handler is present */
@@ -83,7 +86,7 @@ int fwnmi_active;  /* TRUE if an FWNMI handler is present */
 static void pseries_shared_idle_sleep(void);
 static void pseries_dedicated_idle_sleep(void);
 
-struct mpic *pSeries_mpic;
+static struct device_node *pSeries_mpic_node;
 
 static void pSeries_show_cpuinfo(struct seq_file *m)
 {
@@ -118,78 +121,92 @@ static void __init fwnmi_init(void)
                 fwnmi_active = 1;
 }
 
-void pSeries_8259_cascade(unsigned int irq, struct irq_desc *desc,
+void pseries_8259_cascade(unsigned int irq, struct irq_desc *desc,
                           struct pt_regs *regs)
 {
-        unsigned int max = 100;
-
-        while(max--) {
-                int cascade_irq = i8259_irq(regs);
-                if (max == 99)
-                        desc->chip->eoi(irq);
-                if (cascade_irq < 0)
-                        break;
+        unsigned int cascade_irq = i8259_irq(regs);
+        if (cascade_irq != NO_IRQ)
                 generic_handle_irq(cascade_irq, regs);
-        };
+        desc->chip->eoi(irq);
 }
 
-static void __init pSeries_init_mpic(void)
+static void __init pseries_mpic_init_IRQ(void)
 {
+        struct device_node *np, *old, *cascade = NULL;
         unsigned int *addrp;
-        struct device_node *np;
         unsigned long intack = 0;
-
-        /* All ISUs are setup, complete initialization */
-        mpic_init(pSeries_mpic);
-
-        /* Check what kind of cascade ACK we have */
-        if (!(np = of_find_node_by_name(NULL, "pci"))
-            || !(addrp = (unsigned int *)
-                 get_property(np, "8259-interrupt-acknowledge", NULL)))
-                printk(KERN_ERR "Cannot find pci to get ack address\n");
-        else
-                intack = addrp[prom_n_addr_cells(np)-1];
-        of_node_put(np);
-
-        /* Setup the legacy interrupts & controller */
-        i8259_init(intack, 0);
-
-        /* Hook cascade to mpic */
-        set_irq_chained_handler(NUM_ISA_INTERRUPTS, pSeries_8259_cascade);
-}
-
-static void __init pSeries_setup_mpic(void)
-{
         unsigned int *opprop;
         unsigned long openpic_addr = 0;
-        unsigned char senses[NR_IRQS - NUM_ISA_INTERRUPTS];
-        struct device_node *root;
-        int irq_count;
+        unsigned int cascade_irq;
+        int naddr, n, i, opplen;
+        struct mpic *mpic;
 
-        /* Find the Open PIC if present */
-        root = of_find_node_by_path("/");
-        opprop = (unsigned int *) get_property(root, "platform-open-pic", NULL);
+        np = of_find_node_by_path("/");
+        naddr = prom_n_addr_cells(np);
+        opprop = (unsigned int *) get_property(np, "platform-open-pic", &opplen);
         if (opprop != 0) {
-                int n = prom_n_addr_cells(root);
-
-                for (openpic_addr = 0; n > 0; --n)
-                        openpic_addr = (openpic_addr << 32) + *opprop++;
+                openpic_addr = of_read_number(opprop, naddr);
                 printk(KERN_DEBUG "OpenPIC addr: %lx\n", openpic_addr);
         }
-        of_node_put(root);
+        of_node_put(np);
 
         BUG_ON(openpic_addr == 0);
 
-        /* Get the sense values from OF */
-        prom_get_irq_senses(senses, NUM_ISA_INTERRUPTS, NR_IRQS);
-        
         /* Setup the openpic driver */
-        irq_count = NR_IRQS - NUM_ISA_INTERRUPTS - 4; /* leave room for IPIs */
-        pSeries_mpic = mpic_alloc(openpic_addr, MPIC_PRIMARY,
-                                  16, 16, irq_count, /* isu size, irq offset, irq count */ 
-                                  NR_IRQS - 4, /* ipi offset */
-                                  senses, irq_count, /* sense & sense size */
-                                  " MPIC     ");
+        mpic = mpic_alloc(pSeries_mpic_node, openpic_addr,
+                          MPIC_PRIMARY,
+                          16, 250, /* isu size, irq count */
+                          " MPIC     ");
+        BUG_ON(mpic == NULL);
+
+        /* Add ISUs */
+        opplen /= sizeof(u32);
+        for (n = 0, i = naddr; i < opplen; i += naddr, n++) {
+                unsigned long isuaddr = of_read_number(opprop + i, naddr);
+                mpic_assign_isu(mpic, n, isuaddr);
+        }
+
+        /* All ISUs are setup, complete initialization */
+        mpic_init(mpic);
+
+        /* Look for cascade */
+        for_each_node_by_type(np, "interrupt-controller")
+                if (device_is_compatible(np, "chrp,iic")) {
+                        cascade = np;
+                        break;
+                }
+        if (cascade == NULL)
+                return;
+
+        cascade_irq = irq_of_parse_and_map(cascade, 0);
+        if (cascade == NO_IRQ) {
+                printk(KERN_ERR "xics: failed to map cascade interrupt");
+                return;
+        }
+
+        /* Check ACK type */
+        for (old = of_node_get(cascade); old != NULL ; old = np) {
+                np = of_get_parent(old);
+                of_node_put(old);
+                if (np == NULL)
+                        break;
+                if (strcmp(np->name, "pci") != 0)
+                        continue;
+                addrp = (u32 *)get_property(np, "8259-interrupt-acknowledge",
+                                            NULL);
+                if (addrp == NULL)
+                        continue;
+                naddr = prom_n_addr_cells(np);
+                intack = addrp[naddr-1];
+                if (naddr > 1)
+                        intack |= ((unsigned long)addrp[naddr-2]) << 32;
+        }
+        if (intack)
+                printk(KERN_DEBUG "mpic: PCI 8259 intack at 0x%016lx\n",
+                       intack);
+        i8259_init(cascade, intack);
+        of_node_put(cascade);
+        set_irq_chained_handler(cascade_irq, pseries_8259_cascade);
 }
 
 static void pseries_lpar_enable_pmcs(void)
@@ -207,21 +224,67 @@ static void pseries_lpar_enable_pmcs(void)
                 get_lppaca()->pmcregs_in_use = 1;
 }
 
-static void __init pSeries_setup_arch(void)
+#ifdef CONFIG_KEXEC
+static void pseries_kexec_cpu_down_mpic(int crash_shutdown, int secondary)
 {
-        /* Fixup ppc_md depending on the type of interrupt controller */
-        if (ppc64_interrupt_controller == IC_OPEN_PIC) {
-                ppc_md.init_IRQ       = pSeries_init_mpic;
-                ppc_md.get_irq        = mpic_get_irq;
-                /* Allocate the mpic now, so that find_and_init_phbs() can
-                 * fill the ISUs */
-                pSeries_setup_mpic();
-        } else
-                ppc_md.init_IRQ       = xics_init_IRQ;
+        mpic_teardown_this_cpu(secondary);
+}
 
+static void pseries_kexec_cpu_down_xics(int crash_shutdown, int secondary)
+{
+        /* Don't risk a hypervisor call if we're crashing */
+        if (firmware_has_feature(FW_FEATURE_SPLPAR) && !crash_shutdown) {
+                unsigned long vpa = __pa(get_lppaca());
+
+                if (unregister_vpa(hard_smp_processor_id(), vpa)) {
+                        printk("VPA deregistration of cpu %u (hw_cpu_id %d) "
+                                        "failed\n", smp_processor_id(),
+                                        hard_smp_processor_id());
+                }
+        }
+        xics_teardown_cpu(secondary);
+}
+#endif /* CONFIG_KEXEC */
+
+static void __init pseries_discover_pic(void)
+{
+        struct device_node *np;
+        char *typep;
+
+        for (np = NULL; (np = of_find_node_by_name(np,
+                                                   "interrupt-controller"));) {
+                typep = (char *)get_property(np, "compatible", NULL);
+                if (strstr(typep, "open-pic")) {
+                        pSeries_mpic_node = of_node_get(np);
+                        ppc_md.init_IRQ       = pseries_mpic_init_IRQ;
+                        ppc_md.get_irq        = mpic_get_irq;
+#ifdef CONFIG_KEXEC
+                        ppc_md.kexec_cpu_down = pseries_kexec_cpu_down_mpic;
+#endif
 #ifdef CONFIG_SMP
-        smp_init_pSeries();
+                        smp_init_pseries_mpic();
 #endif
+                        return;
+                } else if (strstr(typep, "ppc-xicp")) {
+                        ppc_md.init_IRQ       = xics_init_IRQ;
+#ifdef CONFIG_KEXEC
+                        ppc_md.kexec_cpu_down = pseries_kexec_cpu_down_xics;
+#endif
+#ifdef CONFIG_SMP
+                        smp_init_pseries_xics();
+#endif
+                        return;
+                }
+        }
+        printk(KERN_ERR "pSeries_discover_pic: failed to recognize"
+               " interrupt-controller\n");
+}
+
+static void __init pSeries_setup_arch(void)
+{
+        /* Discover PIC type and setup ppc_md accordingly */
+        pseries_discover_pic();
+
         /* openpic global configuration register (64-bit format). */
         /* openpic Interrupt Source Unit pointer (64-bit format). */
         /* python0 facility area (mmio) (64-bit format) REAL address. */
@@ -273,33 +336,6 @@ static int __init pSeries_init_panel(void)
 }
 arch_initcall(pSeries_init_panel);
 
-static  void __init pSeries_discover_pic(void)
-{
-        struct device_node *np;
-        char *typep;
-
-        /*
-         * Setup interrupt mapping options that are needed for finish_device_tree
-         * to properly parse the OF interrupt tree & do the virtual irq mapping
-         */
-        __irq_offset_value = NUM_ISA_INTERRUPTS;
-        ppc64_interrupt_controller = IC_INVALID;
-        for (np = NULL; (np = of_find_node_by_name(np, "interrupt-controller"));) {
-                typep = (char *)get_property(np, "compatible", NULL);
-                if (strstr(typep, "open-pic")) {
-                        ppc64_interrupt_controller = IC_OPEN_PIC;
-                        break;
-                } else if (strstr(typep, "ppc-xicp")) {
-                        ppc64_interrupt_controller = IC_PPC_XIC;
-                        break;
-                }
-        }
-        if (ppc64_interrupt_controller == IC_INVALID)
-                printk("pSeries_discover_pic: failed to recognize"
-                        " interrupt-controller\n");
-
-}
-
 static void pSeries_mach_cpu_die(void)
 {
         local_irq_disable();
@@ -342,8 +378,6 @@ static void __init pSeries_init_early(void)
 
         iommu_init_early_pSeries();
 
-        pSeries_discover_pic();
-
         DBG(" <- pSeries_init_early()\n");
 }
 
@@ -515,27 +549,6 @@ static int pSeries_pci_probe_mode(struct pci_bus *bus)
         return PCI_PROBE_NORMAL;
 }
 
-#ifdef CONFIG_KEXEC
-static void pseries_kexec_cpu_down(int crash_shutdown, int secondary)
-{
-        /* Don't risk a hypervisor call if we're crashing */
-        if (firmware_has_feature(FW_FEATURE_SPLPAR) && !crash_shutdown) {
-                unsigned long vpa = __pa(get_lppaca());
-
-                if (unregister_vpa(hard_smp_processor_id(), vpa)) {
-                        printk("VPA deregistration of cpu %u (hw_cpu_id %d) "
-                                        "failed\n", smp_processor_id(),
-                                        hard_smp_processor_id());
-                }
-        }
-
-        if (ppc64_interrupt_controller == IC_OPEN_PIC)
-                mpic_teardown_this_cpu(secondary);
-        else
-                xics_teardown_cpu(secondary);
-}
-#endif
-
 define_machine(pseries) {
         .name                   = "pSeries",
         .probe                  = pSeries_probe,
@@ -560,7 +573,6 @@ define_machine(pseries) {
         .system_reset_exception = pSeries_system_reset_exception,
         .machine_check_exception = pSeries_machine_check_exception,
 #ifdef CONFIG_KEXEC
-        .kexec_cpu_down         = pseries_kexec_cpu_down,
         .machine_kexec          = default_machine_kexec,
         .machine_kexec_prepare  = default_machine_kexec_prepare,
         .machine_crash_shutdown = default_machine_crash_shutdown,
diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c
index 4ad144df49c2..ac61098ff401 100644
--- a/arch/powerpc/platforms/pseries/smp.c
+++ b/arch/powerpc/platforms/pseries/smp.c
@@ -416,27 +416,12 @@ static struct smp_ops_t pSeries_xics_smp_ops = {
 #endif
 
 /* This is called very early */
-void __init smp_init_pSeries(void)
+static void __init smp_init_pseries(void)
 {
         int i;
 
         DBG(" -> smp_init_pSeries()\n");
 
-        switch (ppc64_interrupt_controller) {
-#ifdef CONFIG_MPIC
-        case IC_OPEN_PIC:
-                smp_ops = &pSeries_mpic_smp_ops;
-                break;
-#endif
-#ifdef CONFIG_XICS
-        case IC_PPC_XIC:
-                smp_ops = &pSeries_xics_smp_ops;
-                break;
-#endif
-        default:
-                panic("Invalid interrupt controller");
-        }
-
 #ifdef CONFIG_HOTPLUG_CPU
         smp_ops->cpu_disable = pSeries_cpu_disable;
         smp_ops->cpu_die = pSeries_cpu_die;
@@ -471,3 +456,18 @@ void __init smp_init_pSeries(void)
         DBG(" <- smp_init_pSeries()\n");
 }
 
+#ifdef CONFIG_MPIC
+void __init smp_init_pseries_mpic(void)
+{
+        smp_ops = &pSeries_mpic_smp_ops;
+
+        smp_init_pseries();
+}
+#endif
+
+void __init smp_init_pseries_xics(void)
+{
+        smp_ops = &pSeries_xics_smp_ops;
+
+        smp_init_pseries();
+}
diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c
index c7f04420066d..716972aa9777 100644
--- a/arch/powerpc/platforms/pseries/xics.c
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -8,6 +8,9 @@
  *  as published by the Free Software Foundation; either version
  *  2 of the License, or (at your option) any later version.
  */
+
+#undef DEBUG
+
 #include <linux/types.h>
 #include <linux/threads.h>
 #include <linux/kernel.h>
@@ -19,6 +22,7 @@
 #include <linux/gfp.h>
 #include <linux/radix-tree.h>
 #include <linux/cpu.h>
+
 #include <asm/firmware.h>
 #include <asm/prom.h>
 #include <asm/io.h>
@@ -31,9 +35,6 @@
 
 #include "xics.h"
 
-/* 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
 
@@ -64,12 +65,12 @@ struct xics_ipl {
 
 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;
 
+static struct irq_host *xics_host;
+
 /*
  * XICS only has a single IPI, so encode the messages per CPU
  */
@@ -85,7 +86,7 @@ static int ibm_int_off;
 /* Direct HW low level accessors */
 
 
-static inline int direct_xirr_info_get(int n_cpu)
+static inline unsigned int direct_xirr_info_get(int n_cpu)
 {
         return in_be32(&xics_per_cpu[n_cpu]->xirr.word);
 }
@@ -130,7 +131,7 @@ static inline long plpar_xirr(unsigned long *xirr_ret)
         return plpar_hcall(H_XIRR, 0, 0, 0, 0, xirr_ret, &dummy, &dummy);
 }
 
-static inline int lpar_xirr_info_get(int n_cpu)
+static inline unsigned int lpar_xirr_info_get(int n_cpu)
 {
         unsigned long lpar_rc;
         unsigned long return_value;
@@ -138,7 +139,7 @@ static inline int lpar_xirr_info_get(int n_cpu)
         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;
+        return (unsigned int)return_value;
 }
 
 static inline void lpar_xirr_info_set(int n_cpu, int value)
@@ -175,11 +176,11 @@ static inline void lpar_qirr_info(int n_cpu , u8 value)
 
 
 #ifdef CONFIG_SMP
-static int get_irq_server(unsigned int irq)
+static int get_irq_server(unsigned int virq)
 {
         unsigned int server;
         /* For the moment only implement delivery to all cpus or one cpu */
-        cpumask_t cpumask = irq_desc[irq].affinity;
+        cpumask_t cpumask = irq_desc[virq].affinity;
         cpumask_t tmp = CPU_MASK_NONE;
 
         if (!distribute_irqs)
@@ -200,7 +201,7 @@ static int get_irq_server(unsigned int irq)
 
 }
 #else
-static int get_irq_server(unsigned int irq)
+static int get_irq_server(unsigned int virq)
 {
         return default_server;
 }
@@ -213,9 +214,11 @@ static void xics_unmask_irq(unsigned int virq)
         int call_status;
         unsigned int server;
 
-        irq = virt_irq_to_real(irq_offset_down(virq));
-        WARN_ON(irq == NO_IRQ);
-        if (irq == XICS_IPI || irq == NO_IRQ)
+        pr_debug("xics: unmask virq %d\n", virq);
+
+        irq = (unsigned int)irq_map[virq].hwirq;
+        pr_debug(" -> map to hwirq 0x%x\n", irq);
+        if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
                 return;
 
         server = get_irq_server(virq);
@@ -267,75 +270,57 @@ static void xics_mask_irq(unsigned int virq)
 {
         unsigned int irq;
 
-        irq = virt_irq_to_real(irq_offset_down(virq));
-        WARN_ON(irq == NO_IRQ);
-        if (irq != NO_IRQ)
-                xics_mask_real_irq(irq);
+        pr_debug("xics: mask virq %d\n", virq);
+
+        irq = (unsigned int)irq_map[virq].hwirq;
+        if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
+                return;
+        xics_mask_real_irq(irq);
 }
 
-static void xics_set_irq_revmap(unsigned int virq)
+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));
-}
+        /* force a reverse mapping of the interrupt so it gets in the cache */
+        irq = (unsigned int)irq_map[virq].hwirq;
+        irq_radix_revmap(xics_host, irq);
 
-static unsigned int xics_startup(unsigned int virq)
-{
-        xics_set_irq_revmap(virq);
+        /* unmask it */
         xics_unmask_irq(virq);
         return 0;
 }
 
-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;
-}
-
-static void xics_eoi_direct(unsigned int irq)
+static void xics_eoi_direct(unsigned int virq)
 {
         int cpu = smp_processor_id();
+        unsigned int irq = (unsigned int)irq_map[virq].hwirq;
 
         iosync();
-        direct_xirr_info_set(cpu, ((0xff << 24) |
-                                   (virt_irq_to_real(irq_offset_down(irq)))));
+        direct_xirr_info_set(cpu, (0xff << 24) | irq);
 }
 
 
-static void xics_eoi_lpar(unsigned int irq)
+static void xics_eoi_lpar(unsigned int virq)
 {
         int cpu = smp_processor_id();
+        unsigned int irq = (unsigned int)irq_map[virq].hwirq;
 
         iosync();
-        lpar_xirr_info_set(cpu, ((0xff << 24) |
-                                 (virt_irq_to_real(irq_offset_down(irq)))));
-
+        lpar_xirr_info_set(cpu, (0xff << 24) | irq);
 }
 
-static inline int xics_remap_irq(int vec)
+static inline unsigned int xics_remap_irq(unsigned int vec)
 {
-        int irq;
+        unsigned int irq;
 
         vec &= 0x00ffffff;
 
         if (vec == XICS_IRQ_SPURIOUS)
                 return NO_IRQ;
-
-        irq = real_irq_to_virt(vec);
-        if (irq == NO_IRQ)
-                irq = real_irq_to_virt_slowpath(vec);
+        irq = irq_radix_revmap(xics_host, vec);
         if (likely(irq != NO_IRQ))
-                return irq_offset_up(irq);
+                return irq;
 
         printk(KERN_ERR "Interrupt %u (real) is invalid,"
                " disabling it.\n", vec);
@@ -343,14 +328,14 @@ static inline int xics_remap_irq(int vec)
         return NO_IRQ;
 }
 
-static int xics_get_irq_direct(struct pt_regs *regs)
+static unsigned int xics_get_irq_direct(struct pt_regs *regs)
 {
         unsigned int cpu = smp_processor_id();
 
         return xics_remap_irq(direct_xirr_info_get(cpu));
 }
 
-static int xics_get_irq_lpar(struct pt_regs *regs)
+static unsigned int xics_get_irq_lpar(struct pt_regs *regs)
 {
         unsigned int cpu = smp_processor_id();
 
@@ -437,8 +422,8 @@ static void xics_set_affinity(unsigned int virq, cpumask_t cpumask)
         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)
+        irq = (unsigned int)irq_map[virq].hwirq;
+        if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
                 return;
 
         status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
@@ -469,6 +454,24 @@ static void xics_set_affinity(unsigned int virq, cpumask_t cpumask)
         }
 }
 
+void xics_setup_cpu(void)
+{
+        int cpu = smp_processor_id();
+
+        xics_set_cpu_priority(cpu, 0xff);
+
+        /*
+         * 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);
+}
+
+
 static struct irq_chip xics_pic_direct = {
         .typename = " XICS     ",
         .startup = xics_startup,
@@ -489,90 +492,245 @@ static struct irq_chip xics_pic_lpar = {
 };
 
 
-void xics_setup_cpu(void)
+static int xics_host_match(struct irq_host *h, struct device_node *node)
 {
-        int cpu = smp_processor_id();
+        /* IBM machines have interrupt parents of various funky types for things
+         * like vdevices, events, etc... The trick we use here is to match
+         * everything here except the legacy 8259 which is compatible "chrp,iic"
+         */
+        return !device_is_compatible(node, "chrp,iic");
+}
 
-        xics_set_cpu_priority(cpu, 0xff);
+static int xics_host_map_direct(struct irq_host *h, unsigned int virq,
+                                irq_hw_number_t hw, unsigned int flags)
+{
+        unsigned int sense = flags & IRQ_TYPE_SENSE_MASK;
 
-        /*
-         * 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
+        pr_debug("xics: map_direct virq %d, hwirq 0x%lx, flags: 0x%x\n",
+                 virq, hw, flags);
+
+        if (sense && sense != IRQ_TYPE_LEVEL_LOW)
+                printk(KERN_WARNING "xics: using unsupported sense 0x%x"
+                       " for irq %d (h: 0x%lx)\n", flags, virq, hw);
+
+        get_irq_desc(virq)->status |= IRQ_LEVEL;
+        set_irq_chip_and_handler(virq, &xics_pic_direct, handle_fasteoi_irq);
+        return 0;
+}
+
+static int xics_host_map_lpar(struct irq_host *h, unsigned int virq,
+                              irq_hw_number_t hw, unsigned int flags)
+{
+        unsigned int sense = flags & IRQ_TYPE_SENSE_MASK;
+
+        pr_debug("xics: map_lpar virq %d, hwirq 0x%lx, flags: 0x%x\n",
+                 virq, hw, flags);
+
+        if (sense && sense != IRQ_TYPE_LEVEL_LOW)
+                printk(KERN_WARNING "xics: using unsupported sense 0x%x"
+                       " for irq %d (h: 0x%lx)\n", flags, virq, hw);
+
+        get_irq_desc(virq)->status |= IRQ_LEVEL;
+        set_irq_chip_and_handler(virq, &xics_pic_lpar, handle_fasteoi_irq);
+        return 0;
+}
+
+static int xics_host_xlate(struct irq_host *h, struct device_node *ct,
+                           u32 *intspec, unsigned int intsize,
+                           irq_hw_number_t *out_hwirq, unsigned int *out_flags)
+
+{
+        /* Current xics implementation translates everything
+         * to level. It is not technically right for MSIs but this
+         * is irrelevant at this point. We might get smarter in the future
          */
-        rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
-                (1UL << interrupt_server_size) - 1 - default_distrib_server, 1);
+        *out_hwirq = intspec[0];
+        *out_flags = IRQ_TYPE_LEVEL_LOW;
+
+        return 0;
+}
+
+static struct irq_host_ops xics_host_direct_ops = {
+        .match = xics_host_match,
+        .map = xics_host_map_direct,
+        .xlate = xics_host_xlate,
+};
+
+static struct irq_host_ops xics_host_lpar_ops = {
+        .match = xics_host_match,
+        .map = xics_host_map_lpar,
+        .xlate = xics_host_xlate,
+};
+
+static void __init xics_init_host(void)
+{
+        struct irq_host_ops *ops;
+
+        if (firmware_has_feature(FW_FEATURE_LPAR))
+                ops = &xics_host_lpar_ops;
+        else
+                ops = &xics_host_direct_ops;
+        xics_host = irq_alloc_host(IRQ_HOST_MAP_TREE, 0, ops,
+                                   XICS_IRQ_SPURIOUS);
+        BUG_ON(xics_host == NULL);
+        irq_set_default_host(xics_host);
 }
 
-void xics_init_IRQ(void)
+static void __init xics_map_one_cpu(int hw_id, unsigned long addr,
+                                     unsigned long size)
 {
+#ifdef CONFIG_SMP
         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];
-        struct irq_chip *chip;
 
-        ppc64_boot_msg(0x20, "XICS Init");
+        /* This may look gross but it's good enough for now, we don't quite
+         * have a hard -> linux processor id matching.
+         */
+        for_each_possible_cpu(i) {
+                if (!cpu_present(i))
+                        continue;
+                if (hw_id == get_hard_smp_processor_id(i)) {
+                        xics_per_cpu[i] = ioremap(addr, size);
+                        return;
+                }
+        }
+#else
+        if (hw_id != 0)
+                return;
+        xics_per_cpu[0] = ioremap(addr, size);
+#endif /* CONFIG_SMP */
+}
 
-        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");
+static void __init xics_init_one_node(struct device_node *np,
+                                      unsigned int *indx)
+{
+        unsigned int ilen;
+        u32 *ireg;
 
-        np = of_find_node_by_type(NULL, "PowerPC-External-Interrupt-Presentation");
-        if (!np)
-                panic("xics_init_IRQ: can't find interrupt presentation");
+        /* This code does the theorically broken assumption that the interrupt
+         * server numbers are the same as the hard CPU numbers.
+         * This happens to be the case so far but we are playing with fire...
+         * should be fixed one of these days. -BenH.
+         */
+        ireg = (u32 *)get_property(np, "ibm,interrupt-server-ranges", NULL);
 
-nextnode:
-        ireg = (uint *)get_property(np, "ibm,interrupt-server-ranges", NULL);
+        /* Do that ever happen ? we'll know soon enough... but even good'old
+         * f80 does have that property ..
+         */
+        WARN_ON(ireg == NULL);
         if (ireg) {
                 /*
                  * set node starting index for this node
                  */
-                indx = *ireg;
+                *indx = *ireg;
         }
-
-        ireg = (uint *)get_property(np, "reg", &ilen);
+        ireg = (u32 *)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;
+        while (ilen >= (4 * sizeof(u32))) {
+                unsigned long addr, size;
+
+                /* XXX Use proper OF parsing code here !!! */
+                addr = (unsigned long)*ireg++ << 32;
+                ilen -= sizeof(u32);
+                addr |= *ireg++;
+                ilen -= sizeof(u32);
+                size = (unsigned long)*ireg++ << 32;
+                ilen -= sizeof(u32);
+                size |= *ireg++;
+                ilen -= sizeof(u32);
+                xics_map_one_cpu(*indx, addr, size);
+                (*indx)++;
+        }
+}
+
+
+static void __init xics_setup_8259_cascade(void)
+{
+        struct device_node *np, *old, *found = NULL;
+        int cascade, naddr;
+        u32 *addrp;
+        unsigned long intack = 0;
+
+        for_each_node_by_type(np, "interrupt-controller")
+                if (device_is_compatible(np, "chrp,iic")) {
+                        found = np;
+                        break;
+                }
+        if (found == NULL) {
+                printk(KERN_DEBUG "xics: no ISA interrupt controller\n");
+                return;
         }
+        cascade = irq_of_parse_and_map(found, 0);
+        if (cascade == NO_IRQ) {
+                printk(KERN_ERR "xics: failed to map cascade interrupt");
+                return;
+        }
+        pr_debug("xics: cascade mapped to irq %d\n", cascade);
+
+        for (old = of_node_get(found); old != NULL ; old = np) {
+                np = of_get_parent(old);
+                of_node_put(old);
+                if (np == NULL)
+                        break;
+                if (strcmp(np->name, "pci") != 0)
+                        continue;
+                addrp = (u32 *)get_property(np, "8259-interrupt-acknowledge", NULL);
+                if (addrp == NULL)
+                        continue;
+                naddr = prom_n_addr_cells(np);
+                intack = addrp[naddr-1];
+                if (naddr > 1)
+                        intack |= ((unsigned long)addrp[naddr-2]) << 32;
+        }
+        if (intack)
+                printk(KERN_DEBUG "xics: PCI 8259 intack at 0x%016lx\n", intack);
+        i8259_init(found, intack);
+        of_node_put(found);
+        set_irq_chained_handler(cascade, pseries_8259_cascade);
+}
 
-        np = of_find_node_by_type(np, "PowerPC-External-Interrupt-Presentation");
-        if ((indx < NR_CPUS) && np) goto nextnode;
+void __init xics_init_IRQ(void)
+{
+        int i;
+        struct device_node *np;
+        u32 *ireg, ilen, indx = 0;
+        int found = 0;
+
+        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");
+
+        for_each_node_by_type(np, "PowerPC-External-Interrupt-Presentation") {
+                found = 1;
+                if (firmware_has_feature(FW_FEATURE_LPAR))
+                        break;
+                xics_init_one_node(np, &indx);
+        }
+        if (found == 0)
+                return;
+
+        xics_init_host();
 
         /* 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);
+                ireg = (u32 *)get_property(np, "reg", &ilen);
                 if (ireg && ireg[0] == get_hard_smp_processor_id(boot_cpuid)) {
-                        ireg = (uint *)get_property(np, "ibm,ppc-interrupt-gserver#s",
-                                                    &ilen);
+                        ireg = (u32 *)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 */
+                                /* take last element */
+                                default_distrib_server = ireg[i-1];
                         }
-                        ireg = (uint *)get_property(np,
+                        ireg = (u32 *)get_property(np,
                                         "ibm,interrupt-server#-size", NULL);
                         if (ireg)
                                 interrupt_server_size = *ireg;
@@ -581,102 +739,48 @@ nextnode:
         }
         of_node_put(np);
 
-        intr_base = intnodes[0].addr;
-        intr_size = intnodes[0].size;
-
-        if (firmware_has_feature(FW_FEATURE_LPAR)) {
-                ppc_md.get_irq = xics_get_irq_lpar;
-                chip = &xics_pic_lpar;
-        } else {
-#ifdef CONFIG_SMP
-                for_each_possible_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 */
+        if (firmware_has_feature(FW_FEATURE_LPAR))
+                ppc_md.get_irq = xics_get_irq_lpar;
+        else
                 ppc_md.get_irq = xics_get_irq_direct;
-                chip = &xics_pic_direct;
-
-        }
-
-        for (i = irq_offset_value(); i < NR_IRQS; ++i) {
-                /* All IRQs on XICS are level for now. MSI code may want to modify
-                 * that for reporting purposes
-                 */
-                get_irq_desc(i)->status |= IRQ_LEVEL;
-                set_irq_chip_and_handler(i, chip, handle_fasteoi_irq);
-        }
 
         xics_setup_cpu();
 
-        ppc64_boot_msg(0x21, "XICS Done");
-}
+        xics_setup_8259_cascade();
 
-static int xics_setup_8259_cascade(void)
-{
-        struct device_node *np;
-        uint *ireg;
-
-        np = of_find_node_by_type(NULL, "interrupt-controller");
-        if (np == NULL) {
-                printk(KERN_WARNING "xics: no ISA interrupt controller\n");
-                xics_irq_8259_cascade_real = -1;
-                xics_irq_8259_cascade = -1;
-                return 0;
-        }
-
-        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 = irq_offset_up
-                (virt_irq_create_mapping(xics_irq_8259_cascade_real));
-        i8259_init(0, 0);
-        of_node_put(np);
-
-        xics_set_irq_revmap(xics_irq_8259_cascade);
-        set_irq_chained_handler(xics_irq_8259_cascade, pSeries_8259_cascade);
-
-        return 0;
+        ppc64_boot_msg(0x21, "XICS Done");
 }
-arch_initcall(xics_setup_8259_cascade);
 
 
 #ifdef CONFIG_SMP
 void xics_request_IPIs(void)
 {
-        virt_irq_to_real_map[XICS_IPI] = XICS_IPI;
+        unsigned int ipi;
+
+        ipi = irq_create_mapping(xics_host, XICS_IPI, 0);
+        BUG_ON(ipi == NO_IRQ);
 
         /*
          * IPIs are marked IRQF_DISABLED as they must run with irqs
          * disabled
          */
-        set_irq_handler(irq_offset_up(XICS_IPI), handle_percpu_irq);
+        set_irq_handler(ipi, handle_percpu_irq);
         if (firmware_has_feature(FW_FEATURE_LPAR))
-                request_irq(irq_offset_up(XICS_IPI), xics_ipi_action_lpar,
-                            SA_INTERRUPT, "IPI", NULL);
+                request_irq(ipi, xics_ipi_action_lpar, IRQF_DISABLED,
+                            "IPI", NULL);
         else
-                request_irq(irq_offset_up(XICS_IPI), xics_ipi_action_direct,
-                            SA_INTERRUPT, "IPI", NULL);
+                request_irq(ipi, xics_ipi_action_direct, IRQF_DISABLED,
+                            "IPI", NULL);
 }
 #endif /* CONFIG_SMP */
 
 void xics_teardown_cpu(int secondary)
 {
-        struct irq_desc *desc = get_irq_desc(irq_offset_up(XICS_IPI));
         int cpu = smp_processor_id();
+        unsigned int ipi;
+        struct irq_desc *desc;
 
-        xics_set_cpu_priority(cpu, 0);
+        xics_set_cpu_priority(cpu, 0);
 
         /*
          * we need to EOI the IPI if we got here from kexec down IPI
@@ -685,6 +789,11 @@ void xics_teardown_cpu(int secondary)
          * should we be flagging idle loop instead?
          * or creating some task to be scheduled?
          */
+
+        ipi = irq_find_mapping(xics_host, XICS_IPI);
+        if (ipi == XICS_IRQ_SPURIOUS)
+                return;
+        desc = get_irq_desc(ipi);
         if (desc->chip && desc->chip->eoi)
                 desc->chip->eoi(XICS_IPI);
 
@@ -694,8 +803,8 @@ void xics_teardown_cpu(int secondary)
          */
         if (secondary)
                 rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
-                        (1UL << interrupt_server_size) - 1 -
-                        default_distrib_server, 0);
+                                   (1UL << interrupt_server_size) - 1 -
+                                   default_distrib_server, 0);
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -723,15 +832,15 @@ void xics_migrate_irqs_away(void)
                 unsigned long flags;
 
                 /* We cant set affinity on ISA interrupts */
-                if (virq < irq_offset_value())
+                if (virq < NUM_ISA_INTERRUPTS)
                         continue;
-
-                desc = get_irq_desc(virq);
-                irq = virt_irq_to_real(irq_offset_down(virq));
-
+                if (irq_map[virq].host != xics_host)
+                        continue;
+                irq = (unsigned int)irq_map[virq].hwirq;
                 /* We need to get IPIs still. */
-                if (irq == XICS_IPI || irq == NO_IRQ)
+                if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
                         continue;
+                desc = get_irq_desc(virq);
 
                 /* We only need to migrate enabled IRQS */
                 if (desc == NULL || desc->chip == NULL
diff --git a/arch/powerpc/platforms/pseries/xics.h b/arch/powerpc/platforms/pseries/xics.h
index 67dedf3514ec..6ee1055b0ffb 100644
--- a/arch/powerpc/platforms/pseries/xics.h
+++ b/arch/powerpc/platforms/pseries/xics.h
@@ -31,7 +31,7 @@ struct xics_ipi_struct {
 extern struct xics_ipi_struct xics_ipi_message[NR_CPUS] __cacheline_aligned;
 
 struct irq_desc;
-extern void pSeries_8259_cascade(unsigned int irq, struct irq_desc *desc,
+extern void pseries_8259_cascade(unsigned int irq, struct irq_desc *desc,
                                  struct pt_regs *regs);
 
 #endif /* _POWERPC_KERNEL_XICS_H */