This is the framework for using XIVE in a PowerVM guest. The support
is very similar to the native one in a much simpler form.

Instead of OPAL calls, a set of Hypervisors call are used to configure
the interrupt sources and the event/notification queues of the guest:

 - H_INT_GET_SOURCE_INFO

   used to obtain the address of the MMIO page of the Event State
   Buffer (PQ bits) entry associated with the source.

 - H_INT_SET_SOURCE_CONFIG

   assigns a source to a "target".

 - H_INT_GET_SOURCE_CONFIG

   determines to which "target" and "priority" is assigned to a source

 - H_INT_GET_QUEUE_INFO

   returns the address of the notification management page associated
   with the specified "target" and "priority".

 - H_INT_SET_QUEUE_CONFIG

   sets or resets the event queue for a given "target" and "priority".
   It is also used to set the notification config associated with the
   queue, only unconditional notification for the moment.  Reset is
   performed with a queue size of 0 and queueing is disabled in that
   case.

 - H_INT_GET_QUEUE_CONFIG

   returns the queue settings for a given "target" and "priority".

 - H_INT_RESET

   resets all of the partition's interrupt exploitation structures to
   their initial state, losing all configuration set via the hcalls
   H_INT_SET_SOURCE_CONFIG and H_INT_SET_QUEUE_CONFIG.

 - H_INT_SYNC

   issue a synchronisation on a source to make sure sure all
   notifications have reached their queue.

As for XICS, the XIVE interface for the guest is described in the
device tree under the "interrupt-controller" node. A couple of new
properties are specific to XIVE :

 - "reg"

   contains the base address and size of the thread interrupt
   managnement areas (TIMA) for the user level for the OS level. Only
   the OS level is taken into account.

 - "ibm,xive-eq-sizes"

   the size of the event queues.

 - "ibm,xive-lisn-ranges"

   the interrupt numbers ranges assigned to the guest. These are
   allocated using a simple bitmap.

and also :

 - "/ibm,plat-res-int-priorities"

   contains a list of priorities that the hypervisor has reserved for
   its own use.

Tested with a QEMU XIVE model for pseries and with the Power
hypervisor

Signed-off-by: Cédric Le Goater <c...@kaod.org>
---

 Changes since v1 :

 - added a xive_teardown_cpu() routine
 - removed P9 doorbell support when xive is enabled.
 - merged in patch for "ibm,plat-res-int-priorities" support
 - added some comments on the usage of raw I/O accessors.
 
 Changes since RFC :

 - renamed backend to spapr
 - fixed hotplug support
 - fixed kexec support
 - fixed src_chip value (XIVE_INVALID_CHIP_ID)
 - added doorbell support 
 - added some hcall debug logs

 arch/powerpc/include/asm/hvcall.h            |  13 +-
 arch/powerpc/include/asm/xive.h              |   3 +
 arch/powerpc/platforms/pseries/Kconfig       |   1 +
 arch/powerpc/platforms/pseries/hotplug-cpu.c |  11 +-
 arch/powerpc/platforms/pseries/kexec.c       |   6 +-
 arch/powerpc/platforms/pseries/setup.c       |   8 +-
 arch/powerpc/platforms/pseries/smp.c         |  27 +-
 arch/powerpc/sysdev/xive/Kconfig             |   5 +
 arch/powerpc/sysdev/xive/Makefile            |   1 +
 arch/powerpc/sysdev/xive/common.c            |  13 +
 arch/powerpc/sysdev/xive/spapr.c             | 617 +++++++++++++++++++++++++++
 11 files changed, 697 insertions(+), 8 deletions(-)
 create mode 100644 arch/powerpc/sysdev/xive/spapr.c

diff --git a/arch/powerpc/include/asm/hvcall.h 
b/arch/powerpc/include/asm/hvcall.h
index 57d38b504ff7..3d34dc0869f6 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -280,7 +280,18 @@
 #define H_RESIZE_HPT_COMMIT    0x370
 #define H_REGISTER_PROC_TBL    0x37C
 #define H_SIGNAL_SYS_RESET     0x380
-#define MAX_HCALL_OPCODE       H_SIGNAL_SYS_RESET
+#define H_INT_GET_SOURCE_INFO   0x3A8
+#define H_INT_SET_SOURCE_CONFIG 0x3AC
+#define H_INT_GET_SOURCE_CONFIG 0x3B0
+#define H_INT_GET_QUEUE_INFO    0x3B4
+#define H_INT_SET_QUEUE_CONFIG  0x3B8
+#define H_INT_GET_QUEUE_CONFIG  0x3BC
+#define H_INT_SET_OS_REPORTING_LINE 0x3C0
+#define H_INT_GET_OS_REPORTING_LINE 0x3C4
+#define H_INT_ESB               0x3C8
+#define H_INT_SYNC              0x3CC
+#define H_INT_RESET             0x3D0
+#define MAX_HCALL_OPCODE       H_INT_RESET
 
 /* H_VIOCTL functions */
 #define H_GET_VIOA_DUMP_SIZE   0x01
diff --git a/arch/powerpc/include/asm/xive.h b/arch/powerpc/include/asm/xive.h
index c23ff4389ca2..473f133a8555 100644
--- a/arch/powerpc/include/asm/xive.h
+++ b/arch/powerpc/include/asm/xive.h
@@ -110,11 +110,13 @@ extern bool __xive_enabled;
 
 static inline bool xive_enabled(void) { return __xive_enabled; }
 
+extern bool xive_spapr_init(void);
 extern bool xive_native_init(void);
 extern void xive_smp_probe(void);
 extern int  xive_smp_prepare_cpu(unsigned int cpu);
 extern void xive_smp_setup_cpu(void);
 extern void xive_smp_disable_cpu(void);
+extern void xive_teardown_cpu(void);
 extern void xive_kexec_teardown_cpu(int secondary);
 extern void xive_shutdown(void);
 extern void xive_flush_interrupt(void);
@@ -147,6 +149,7 @@ extern int xive_native_get_vp_info(u32 vp_id, u32 
*out_cam_id, u32 *out_chip_id)
 
 static inline bool xive_enabled(void) { return false; }
 
+static inline bool xive_spapr_init(void) { return false; }
 static inline bool xive_native_init(void) { return false; }
 static inline void xive_smp_probe(void) { }
 extern inline int  xive_smp_prepare_cpu(unsigned int cpu) { return -EINVAL; }
diff --git a/arch/powerpc/platforms/pseries/Kconfig 
b/arch/powerpc/platforms/pseries/Kconfig
index 3a6dfd14f64b..71dd69d9ec64 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -7,6 +7,7 @@ config PPC_PSERIES
        select PCI
        select PCI_MSI
        select PPC_XICS
+       select PPC_XIVE_SPAPR
        select PPC_ICP_NATIVE
        select PPC_ICP_HV
        select PPC_ICS_RTAS
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c 
b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 6afd1efd3633..175230e80766 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -34,6 +34,7 @@
 #include <asm/machdep.h>
 #include <asm/vdso_datapage.h>
 #include <asm/xics.h>
+#include <asm/xive.h>
 #include <asm/plpar_wrappers.h>
 
 #include "pseries.h"
@@ -109,7 +110,10 @@ static void pseries_mach_cpu_die(void)
 
        local_irq_disable();
        idle_task_exit();
-       xics_teardown_cpu();
+       if (xive_enabled())
+               xive_teardown_cpu();
+       else
+               xics_teardown_cpu();
 
        if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
                set_cpu_current_state(cpu, CPU_STATE_INACTIVE);
@@ -174,7 +178,10 @@ static int pseries_cpu_disable(void)
                boot_cpuid = cpumask_any(cpu_online_mask);
 
        /* FIXME: abstract this to not be platform specific later on */
-       xics_migrate_irqs_away();
+       if (xive_enabled())
+               xive_smp_disable_cpu();
+       else
+               xics_migrate_irqs_away();
        return 0;
 }
 
diff --git a/arch/powerpc/platforms/pseries/kexec.c 
b/arch/powerpc/platforms/pseries/kexec.c
index 6681ac97fb18..eeb13429d685 100644
--- a/arch/powerpc/platforms/pseries/kexec.c
+++ b/arch/powerpc/platforms/pseries/kexec.c
@@ -15,6 +15,7 @@
 #include <asm/firmware.h>
 #include <asm/kexec.h>
 #include <asm/xics.h>
+#include <asm/xive.h>
 #include <asm/smp.h>
 #include <asm/plpar_wrappers.h>
 
@@ -51,5 +52,8 @@ void pseries_kexec_cpu_down(int crash_shutdown, int secondary)
                }
        }
 
-       xics_kexec_teardown_cpu(secondary);
+       if (xive_enabled())
+               xive_kexec_teardown_cpu(secondary);
+       else
+               xics_kexec_teardown_cpu(secondary);
 }
diff --git a/arch/powerpc/platforms/pseries/setup.c 
b/arch/powerpc/platforms/pseries/setup.c
index b5d86426e97b..a8531e012658 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -57,6 +57,7 @@
 #include <asm/nvram.h>
 #include <asm/pmc.h>
 #include <asm/xics.h>
+#include <asm/xive.h>
 #include <asm/ppc-pci.h>
 #include <asm/i8259.h>
 #include <asm/udbg.h>
@@ -176,8 +177,11 @@ static void __init pseries_setup_i8259_cascade(void)
 
 static void __init pseries_init_irq(void)
 {
-       xics_init();
-       pseries_setup_i8259_cascade();
+       /* Try using a XIVE if available, otherwise use a XICS */
+       if (!xive_spapr_init()) {
+               xics_init();
+               pseries_setup_i8259_cascade();
+       }
 }
 
 static void pseries_lpar_enable_pmcs(void)
diff --git a/arch/powerpc/platforms/pseries/smp.c 
b/arch/powerpc/platforms/pseries/smp.c
index 24785f63fb40..2e184829e5d4 100644
--- a/arch/powerpc/platforms/pseries/smp.c
+++ b/arch/powerpc/platforms/pseries/smp.c
@@ -41,6 +41,7 @@
 #include <asm/vdso_datapage.h>
 #include <asm/cputhreads.h>
 #include <asm/xics.h>
+#include <asm/xive.h>
 #include <asm/dbell.h>
 #include <asm/plpar_wrappers.h>
 #include <asm/code-patching.h>
@@ -136,7 +137,9 @@ static inline int smp_startup_cpu(unsigned int lcpu)
 
 static void smp_setup_cpu(int cpu)
 {
-       if (cpu != boot_cpuid)
+       if (xive_enabled())
+               xive_smp_setup_cpu();
+       else if (cpu != boot_cpuid)
                xics_setup_cpu();
 
        if (firmware_has_feature(FW_FEATURE_SPLPAR))
@@ -181,6 +184,13 @@ static int smp_pSeries_kick_cpu(int nr)
        return 0;
 }
 
+static int pseries_smp_prepare_cpu(int cpu)
+{
+       if (xive_enabled())
+               return xive_smp_prepare_cpu(cpu);
+       return 0;
+}
+
 static void smp_pseries_cause_ipi(int cpu)
 {
        /* POWER9 should not use this handler */
@@ -211,7 +221,7 @@ static int pseries_cause_nmi_ipi(int cpu)
        return 0;
 }
 
-static __init void pSeries_smp_probe(void)
+static __init void pSeries_smp_probe_xics(void)
 {
        xics_smp_probe();
 
@@ -221,11 +231,24 @@ static __init void pSeries_smp_probe(void)
                smp_ops->cause_ipi = icp_ops->cause_ipi;
 }
 
+static __init void pSeries_smp_probe(void)
+{
+       if (xive_enabled())
+               /*
+                * Don't use P9 doorbells when XIVE is enabled. IPIs
+                * using MMIOs should be faster
+                */
+               xive_smp_probe();
+       else
+               pSeries_smp_probe_xics();
+}
+
 static struct smp_ops_t pseries_smp_ops = {
        .message_pass   = NULL, /* Use smp_muxed_ipi_message_pass */
        .cause_ipi      = NULL, /* Filled at runtime by pSeries_smp_probe() */
        .cause_nmi_ipi  = pseries_cause_nmi_ipi,
        .probe          = pSeries_smp_probe,
+       .prepare_cpu    = pseries_smp_prepare_cpu,
        .kick_cpu       = smp_pSeries_kick_cpu,
        .setup_cpu      = smp_setup_cpu,
        .cpu_bootable   = smp_generic_cpu_bootable,
diff --git a/arch/powerpc/sysdev/xive/Kconfig b/arch/powerpc/sysdev/xive/Kconfig
index 12ccd7373d2f..3e3e25b5e30d 100644
--- a/arch/powerpc/sysdev/xive/Kconfig
+++ b/arch/powerpc/sysdev/xive/Kconfig
@@ -9,3 +9,8 @@ config PPC_XIVE_NATIVE
        default n
        select PPC_XIVE
        depends on PPC_POWERNV
+
+config PPC_XIVE_SPAPR
+       bool
+       default n
+       select PPC_XIVE
diff --git a/arch/powerpc/sysdev/xive/Makefile 
b/arch/powerpc/sysdev/xive/Makefile
index 3fab303fc169..536d6e5706e3 100644
--- a/arch/powerpc/sysdev/xive/Makefile
+++ b/arch/powerpc/sysdev/xive/Makefile
@@ -2,3 +2,4 @@ subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
 
 obj-y                          += common.o
 obj-$(CONFIG_PPC_XIVE_NATIVE)  += native.o
+obj-$(CONFIG_PPC_XIVE_SPAPR)   += spapr.o
diff --git a/arch/powerpc/sysdev/xive/common.c 
b/arch/powerpc/sysdev/xive/common.c
index 26999ceae20e..8774af7a4105 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -1368,6 +1368,19 @@ void xive_flush_interrupt(void)
 
 #endif /* CONFIG_SMP */
 
+void xive_teardown_cpu(void)
+{
+       struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+       unsigned int cpu = smp_processor_id();
+
+       /* Set CPPR to 0 to disable flow of interrupts */
+       xc->cppr = 0;
+       out_8(xive_tima + xive_tima_offset + TM_CPPR, 0);
+
+       if (xive_ops->teardown_cpu)
+               xive_ops->teardown_cpu(cpu, xc);
+}
+
 void xive_kexec_teardown_cpu(int secondary)
 {
        struct xive_cpu *xc = __this_cpu_read(xive_cpu);
diff --git a/arch/powerpc/sysdev/xive/spapr.c b/arch/powerpc/sysdev/xive/spapr.c
new file mode 100644
index 000000000000..89e5a57693db
--- /dev/null
+++ b/arch/powerpc/sysdev/xive/spapr.c
@@ -0,0 +1,617 @@
+/*
+ * Copyright 2016,2017 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.
+ */
+
+#define pr_fmt(fmt) "xive: " fmt
+
+#include <linux/types.h>
+#include <linux/irq.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/cpumask.h>
+#include <linux/mm.h>
+
+#include <asm/prom.h>
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/irq.h>
+#include <asm/errno.h>
+#include <asm/xive.h>
+#include <asm/xive-regs.h>
+#include <asm/hvcall.h>
+
+#include "xive-internal.h"
+
+static u32 xive_queue_shift;
+
+struct xive_irq_bitmap {
+       unsigned long           *bitmap;
+       unsigned int            base;
+       unsigned int            count;
+       spinlock_t              lock;
+       struct list_head        list;
+};
+
+static LIST_HEAD(xive_irq_bitmaps);
+
+static int xive_irq_bitmap_add(int base, int count)
+{
+       struct xive_irq_bitmap *xibm;
+
+       xibm = kzalloc(sizeof(*xibm), GFP_ATOMIC);
+       if (!xibm)
+               return -ENOMEM;
+
+       spin_lock_init(&xibm->lock);
+       xibm->base = base;
+       xibm->count = count;
+       xibm->bitmap = kzalloc(xibm->count, GFP_KERNEL);
+       list_add(&xibm->list, &xive_irq_bitmaps);
+
+       pr_info("Using IRQ range [%x-%x]", xibm->base,
+               xibm->base + xibm->count - 1);
+       return 0;
+}
+
+static int __xive_irq_bitmap_alloc(struct xive_irq_bitmap *xibm)
+{
+       int irq;
+
+       irq = find_first_zero_bit(xibm->bitmap, xibm->count);
+       if (irq != xibm->count) {
+               set_bit(irq, xibm->bitmap);
+               irq += xibm->base;
+       } else {
+               irq = -ENOMEM;
+       }
+
+       return irq;
+}
+
+static int xive_irq_bitmap_alloc(void)
+{
+       struct xive_irq_bitmap *xibm;
+       unsigned long flags;
+       int irq = -ENOENT;
+
+       list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
+               spin_lock_irqsave(&xibm->lock, flags);
+               irq = __xive_irq_bitmap_alloc(xibm);
+               spin_unlock_irqrestore(&xibm->lock, flags);
+               if (irq >= 0)
+                       break;
+       }
+       return irq;
+}
+
+static void xive_irq_bitmap_free(int irq)
+{
+       unsigned long flags;
+       struct xive_irq_bitmap *xibm;
+
+       list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
+               if ((irq >= xibm->base) && (irq < xibm->base + xibm->count)) {
+                       spin_lock_irqsave(&xibm->lock, flags);
+                       clear_bit(irq - xibm->base, xibm->bitmap);
+                       spin_unlock_irqrestore(&xibm->lock, flags);
+                       break;
+               }
+       }
+}
+
+static long plpar_int_get_source_info(unsigned long flags,
+                                     unsigned long lisn,
+                                     unsigned long *src_flags,
+                                     unsigned long *eoi_page,
+                                     unsigned long *trig_page,
+                                     unsigned long *esb_shift)
+{
+       unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+       long rc;
+
+       rc = plpar_hcall(H_INT_GET_SOURCE_INFO, retbuf, flags, lisn);
+       if (rc) {
+               pr_err("H_INT_GET_SOURCE_INFO lisn=%ld failed %ld\n", lisn, rc);
+               return rc;
+       }
+
+       *src_flags = retbuf[0];
+       *eoi_page  = retbuf[1];
+       *trig_page = retbuf[2];
+       *esb_shift = retbuf[3];
+
+       pr_devel("H_INT_GET_SOURCE_INFO flags=%lx eoi=%lx trig=%lx shift=%lx\n",
+               retbuf[0], retbuf[1], retbuf[2], retbuf[3]);
+
+       return 0;
+}
+
+#define XIVE_SRC_SET_EISN (1ull << (63 - 62))
+#define XIVE_SRC_MASK     (1ull << (63 - 63)) /* unused */
+
+static long plpar_int_set_source_config(unsigned long flags,
+                                       unsigned long lisn,
+                                       unsigned long target,
+                                       unsigned long prio,
+                                       unsigned long sw_irq)
+{
+       long rc;
+
+
+       pr_devel("H_INT_SET_SOURCE_CONFIG flags=%lx lisn=%lx target=%lx 
prio=%lx sw_irq=%lx\n",
+               flags, lisn, target, prio, sw_irq);
+
+
+       rc = plpar_hcall_norets(H_INT_SET_SOURCE_CONFIG, flags, lisn,
+                               target, prio, sw_irq);
+       if (rc) {
+               pr_err("H_INT_SET_SOURCE_CONFIG lisn=%ld target=%lx prio=%lx 
failed %ld\n",
+                      lisn, target, prio, rc);
+               return rc;
+       }
+
+       return 0;
+}
+
+static long plpar_int_get_queue_info(unsigned long flags,
+                                    unsigned long target,
+                                    unsigned long priority,
+                                    unsigned long *esn_page,
+                                    unsigned long *esn_size)
+{
+       unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+       long rc;
+
+       rc = plpar_hcall(H_INT_GET_QUEUE_INFO, retbuf, flags, target, priority);
+       if (rc) {
+               pr_err("H_INT_GET_QUEUE_INFO cpu=%ld prio=%ld failed %ld\n",
+                      target, priority, rc);
+               return rc;
+       }
+
+       *esn_page = retbuf[0];
+       *esn_size = retbuf[1];
+
+       pr_devel("H_INT_GET_QUEUE_INFO page=%lx size=%lx\n",
+               retbuf[0], retbuf[1]);
+
+       return 0;
+}
+
+#define XIVE_EQ_ALWAYS_NOTIFY (1ull << (63 - 63))
+
+static long plpar_int_set_queue_config(unsigned long flags,
+                                      unsigned long target,
+                                      unsigned long priority,
+                                      unsigned long qpage,
+                                      unsigned long qsize)
+{
+       long rc;
+
+       pr_devel("H_INT_SET_QUEUE_CONFIG flags=%lx target=%lx priority=%lx 
qpage=%lx qsize=%lx\n",
+               flags,  target, priority, qpage, qsize);
+
+       rc = plpar_hcall_norets(H_INT_SET_QUEUE_CONFIG, flags, target,
+                               priority, qpage, qsize);
+       if (rc) {
+               pr_err("H_INT_SET_QUEUE_CONFIG cpu=%ld prio=%ld qpage=%lx 
returned %ld\n",
+                      target, priority, qpage, rc);
+               return  rc;
+       }
+
+       return 0;
+}
+
+static long plpar_int_sync(unsigned long flags)
+{
+       long rc;
+
+       rc = plpar_hcall_norets(H_INT_SYNC, flags);
+       if (rc) {
+               pr_err("H_INT_SYNC returned %ld\n", rc);
+               return  rc;
+       }
+
+       return 0;
+}
+
+#define XIVE_SRC_H_INT_ESB     (1ull << (63 - 60)) /* TODO */
+#define XIVE_SRC_LSI           (1ull << (63 - 61))
+#define XIVE_SRC_TRIGGER       (1ull << (63 - 62))
+#define XIVE_SRC_STORE_EOI     (1ull << (63 - 63))
+
+static int xive_spapr_populate_irq_data(u32 hw_irq, struct xive_irq_data *data)
+{
+       long rc;
+       unsigned long flags;
+       unsigned long eoi_page;
+       unsigned long trig_page;
+       unsigned long esb_shift;
+
+       memset(data, 0, sizeof(*data));
+
+       rc = plpar_int_get_source_info(0, hw_irq, &flags, &eoi_page, &trig_page,
+                                      &esb_shift);
+       if (rc)
+               return  -EINVAL;
+
+       if (flags & XIVE_SRC_STORE_EOI)
+               data->flags  |= XIVE_IRQ_FLAG_STORE_EOI;
+       if (flags & XIVE_SRC_LSI)
+               data->flags  |= XIVE_IRQ_FLAG_LSI;
+       data->eoi_page  = eoi_page;
+       data->esb_shift = esb_shift;
+       data->trig_page = trig_page;
+
+       /*
+        * No chip-id for the sPAPR backend. This has an impact how we
+        * pick a target. See xive_pick_irq_target().
+        */
+       data->src_chip = XIVE_INVALID_CHIP_ID;
+
+       data->eoi_mmio = ioremap(data->eoi_page, 1u << data->esb_shift);
+       if (!data->eoi_mmio) {
+               pr_err("Failed to map EOI page for irq 0x%x\n", hw_irq);
+               return -ENOMEM;
+       }
+
+       /* Full function page supports trigger */
+       if (flags & XIVE_SRC_TRIGGER) {
+               data->trig_mmio = data->eoi_mmio;
+               return 0;
+       }
+
+       data->trig_mmio = ioremap(data->trig_page, 1u << data->esb_shift);
+       if (!data->trig_mmio) {
+               pr_err("Failed to map trigger page for irq 0x%x\n", hw_irq);
+               return -ENOMEM;
+       }
+       return 0;
+}
+
+static int xive_spapr_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 
sw_irq)
+{
+       long rc;
+
+       rc = plpar_int_set_source_config(XIVE_SRC_SET_EISN, hw_irq, target,
+                                        prio, sw_irq);
+
+       return rc == 0 ? 0 : -ENXIO;
+}
+
+/* This can be called multiple time to change a queue configuration */
+static int xive_spapr_configure_queue(u32 target, struct xive_q *q, u8 prio,
+                                  __be32 *qpage, u32 order)
+{
+       s64 rc = 0;
+       unsigned long esn_page;
+       unsigned long esn_size;
+       u64 flags, qpage_phys;
+
+       /* If there's an actual queue page, clean it */
+       if (order) {
+               if (WARN_ON(!qpage))
+                       return -EINVAL;
+               qpage_phys = __pa(qpage);
+       } else {
+               qpage_phys = 0;
+       }
+
+       /* Initialize the rest of the fields */
+       q->msk = order ? ((1u << (order - 2)) - 1) : 0;
+       q->idx = 0;
+       q->toggle = 0;
+
+       rc = plpar_int_get_queue_info(0, target, prio, &esn_page, &esn_size);
+       if (rc) {
+               pr_err("Error %lld getting queue info prio %d\n", rc, prio);
+               rc = -EIO;
+               goto fail;
+       }
+
+       /* TODO: add support for the notification page */
+       q->eoi_phys = esn_page;
+
+       /* Default is to always notify */
+       flags = XIVE_EQ_ALWAYS_NOTIFY;
+
+       /* Configure and enable the queue in HW */
+       rc = plpar_int_set_queue_config(flags, target, prio, qpage_phys, order);
+       if (rc) {
+               pr_err("Error %lld setting queue for prio %d\n", rc, prio);
+               rc = -EIO;
+       } else {
+               q->qpage = qpage;
+       }
+fail:
+       return rc;
+}
+
+static int xive_spapr_setup_queue(unsigned int cpu, struct xive_cpu *xc,
+                                 u8 prio)
+{
+       struct xive_q *q = &xc->queue[prio];
+       __be32 *qpage;
+
+       qpage = xive_queue_page_alloc(cpu, xive_queue_shift);
+       if (IS_ERR(qpage))
+               return PTR_ERR(qpage);
+
+       return xive_spapr_configure_queue(cpu, q, prio, qpage,
+                                         xive_queue_shift);
+}
+
+static void xive_spapr_cleanup_queue(unsigned int cpu, struct xive_cpu *xc,
+                                 u8 prio)
+{
+       struct xive_q *q = &xc->queue[prio];
+       unsigned int alloc_order;
+       long rc;
+
+       rc = plpar_int_set_queue_config(0, cpu, prio, 0, 0);
+       if (rc)
+               pr_err("Error %ld setting queue for prio %d\n", rc, prio);
+
+       alloc_order = xive_alloc_order(xive_queue_shift);
+       free_pages((unsigned long)q->qpage, alloc_order);
+       q->qpage = NULL;
+}
+
+static bool xive_spapr_match(struct device_node *node)
+{
+       return 1;
+}
+
+#ifdef CONFIG_SMP
+static int xive_spapr_get_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+       int irq = xive_irq_bitmap_alloc();
+
+       if (irq < 0) {
+               pr_err("Failed to allocate IPI on CPU %d\n", cpu);
+               return -ENXIO;
+       }
+
+       xc->hw_ipi = irq;
+       return 0;
+}
+
+static void xive_spapr_put_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+       xive_irq_bitmap_free(xc->hw_ipi);
+}
+#endif /* CONFIG_SMP */
+
+static void xive_spapr_shutdown(void)
+{
+       long rc;
+
+       rc = plpar_hcall_norets(H_INT_RESET, 0);
+       if (rc)
+               pr_err("H_INT_RESET failed %ld\n", rc);
+}
+
+/*
+ * Perform an "ack" cycle on the current thread. Grab the pending
+ * active priorities and update the CPPR to the most favored one.
+ */
+static void xive_spapr_update_pending(struct xive_cpu *xc)
+{
+       u8 nsr, cppr;
+       u16 ack;
+
+       /*
+        * Perform the "Acknowledge O/S to Register" cycle.
+        *
+        * Let's speedup the access to the TIMA using the raw I/O
+        * accessor as we don't need the synchronisation routine of
+        * the higher level ones
+        */
+       ack = be16_to_cpu(__raw_readw(xive_tima + TM_SPC_ACK_OS_REG));
+
+       /* Synchronize subsequent queue accesses */
+       mb();
+
+       /*
+        * Grab the CPPR and the "NSR" field which indicates the source
+        * of the interrupt (if any)
+        */
+       cppr = ack & 0xff;
+       nsr = ack >> 8;
+
+       if (nsr & TM_QW1_NSR_EO) {
+               if (cppr == 0xff)
+                       return;
+               /* Mark the priority pending */
+               xc->pending_prio |= 1 << cppr;
+
+               /*
+                * A new interrupt should never have a CPPR less favored
+                * than our current one.
+                */
+               if (cppr >= xc->cppr)
+                       pr_err("CPU %d odd ack CPPR, got %d at %d\n",
+                              smp_processor_id(), cppr, xc->cppr);
+
+               /* Update our idea of what the CPPR is */
+               xc->cppr = cppr;
+       }
+}
+
+static void xive_spapr_eoi(u32 hw_irq)
+{
+       /* Not used */;
+}
+
+static void xive_spapr_setup_cpu(unsigned int cpu, struct xive_cpu *xc)
+{
+       /* Only some debug on the TIMA settings */
+       pr_debug("(HW value: %08x %08x %08x)\n",
+                in_be32(xive_tima + TM_QW1_OS + TM_WORD0),
+                in_be32(xive_tima + TM_QW1_OS + TM_WORD1),
+                in_be32(xive_tima + TM_QW1_OS + TM_WORD2));
+}
+
+static void xive_spapr_teardown_cpu(unsigned int cpu, struct xive_cpu *xc)
+{
+       /* Nothing to do */;
+}
+
+static void xive_spapr_sync_source(u32 hw_irq)
+{
+       /* Specs are unclear on what this is doing */
+       plpar_int_sync(0);
+}
+
+static const struct xive_ops xive_spapr_ops = {
+       .populate_irq_data      = xive_spapr_populate_irq_data,
+       .configure_irq          = xive_spapr_configure_irq,
+       .setup_queue            = xive_spapr_setup_queue,
+       .cleanup_queue          = xive_spapr_cleanup_queue,
+       .match                  = xive_spapr_match,
+       .shutdown               = xive_spapr_shutdown,
+       .update_pending         = xive_spapr_update_pending,
+       .eoi                    = xive_spapr_eoi,
+       .setup_cpu              = xive_spapr_setup_cpu,
+       .teardown_cpu           = xive_spapr_teardown_cpu,
+       .sync_source            = xive_spapr_sync_source,
+#ifdef CONFIG_SMP
+       .get_ipi                = xive_spapr_get_ipi,
+       .put_ipi                = xive_spapr_put_ipi,
+#endif /* CONFIG_SMP */
+       .name                   = "spapr",
+};
+
+/*
+ * get max priority from "/ibm,plat-res-int-priorities"
+ */
+static bool xive_get_max_prio(u8 *max_prio)
+{
+       struct device_node *rootdn;
+       const __be32 *reg;
+       u32 len;
+       int prio, found;
+
+       rootdn = of_find_node_by_path("/");
+       if (!rootdn) {
+               pr_err("not root node found !\n");
+               return false;
+       }
+
+       reg = of_get_property(rootdn, "ibm,plat-res-int-priorities", &len);
+       if (!reg) {
+               pr_err("Failed to read 'ibm,plat-res-int-priorities' 
property\n");
+               return false;
+       }
+
+       if (len % (2 * sizeof(u32)) != 0) {
+               pr_err("invalid 'ibm,plat-res-int-priorities' property\n");
+               return false;
+       }
+
+       /* HW supports priorities in the range [0-7] and 0xFF is a
+        * wildcard priority used to mask. We scan the ranges reserved
+        * by the hypervisor to find the lowest priority we can use.
+        */
+       found = 0xFF;
+       for (prio = 0; prio < 8; prio++) {
+               int reserved = 0;
+               int i;
+
+               for (i = 0; i < len / (2 * sizeof(u32)); i++) {
+                       int base  = be32_to_cpu(reg[2 * i]);
+                       int range = be32_to_cpu(reg[2 * i + 1]);
+
+                       if (prio >= base && prio < base + range)
+                               reserved++;
+               }
+
+               if (!reserved)
+                       found = prio;
+       }
+
+       if (found == 0xFF) {
+               pr_err("no valid priority found in 
'ibm,plat-res-int-priorities'\n");
+               return false;
+       }
+
+       *max_prio = found;
+       return true;
+}
+
+bool xive_spapr_init(void)
+{
+       struct device_node *np;
+       struct resource r;
+       void __iomem *tima;
+       struct property *prop;
+       u8 max_prio;
+       u32 val;
+       u32 len;
+       const __be32 *reg;
+       int i;
+
+       if (xive_cmdline_disabled)
+               return false;
+
+       pr_devel("%s()\n", __func__);
+       np = of_find_compatible_node(NULL, NULL, "ibm,power-ivpe");
+       if (!np) {
+               pr_devel("not found !\n");
+               return false;
+       }
+       pr_devel("Found %s\n", np->full_name);
+
+       /* Resource 1 is the OS ring TIMA */
+       if (of_address_to_resource(np, 1, &r)) {
+               pr_err("Failed to get thread mgmnt area resource\n");
+               return false;
+       }
+       tima = ioremap(r.start, resource_size(&r));
+       if (!tima) {
+               pr_err("Failed to map thread mgmnt area\n");
+               return false;
+       }
+
+       if (!xive_get_max_prio(&max_prio))
+               return false;
+
+       /* Feed the IRQ number allocator with the ranges given in the DT */
+       reg = of_get_property(np, "ibm,xive-lisn-ranges", &len);
+       if (!reg) {
+               pr_err("Failed to read 'ibm,xive-lisn-ranges' property\n");
+               return false;
+       }
+
+       if (len % (2 * sizeof(u32)) != 0) {
+               pr_err("invalid 'ibm,xive-lisn-ranges' property\n");
+               return false;
+       }
+
+       for (i = 0; i < len / (2 * sizeof(u32)); i++, reg += 2)
+               xive_irq_bitmap_add(be32_to_cpu(reg[0]),
+                                   be32_to_cpu(reg[1]));
+
+       /* Iterate the EQ sizes and pick one */
+       of_property_for_each_u32(np, "ibm,xive-eq-sizes", prop, reg, val) {
+               xive_queue_shift = val;
+               if (val == PAGE_SHIFT)
+                       break;
+       }
+
+       /* Initialize XIVE core with our backend */
+       if (!xive_core_init(&xive_spapr_ops, tima, TM_QW1_OS, max_prio))
+               return false;
+
+       pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
+       return true;
+}
-- 
2.13.4

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