[v2,04/10] powerpc/xive: Native exploitation of the XIVE interrupt controller

diff --git a/arch/powerpc/include/asm/xive-regs.h b/arch/powerpc/include/asm/xive-regs.h
new file mode 100644
index 0000000..3dbaf41
--- /dev/null
+++ b/arch/powerpc/include/asm/xive-regs.h
@@ -0,0 +1,96 @@ 
+/*
+ * 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.
+ */
+#ifndef __XIVE_REGS_H__
+#define __XIVE_REGS_H__
+
+/*
+ * Thread Management (aka "TM") registers
+ */
+
+/* TM register offsets */
+#define TM_QW0_USER		0x000 /* All rings */
+#define TM_QW1_OS		0x010 /* Ring 0..2 */
+#define TM_QW2_HV_POOL		0x020 /* Ring 0..1 */
+#define TM_QW3_HV_PHYS		0x030 /* Ring 0..1 */
+
+/* Byte offsets inside a QW             QW0 QW1 QW2 QW3 */
+#define TM_NSR			0x0  /*  +   +   -   +  */
+#define TM_CPPR			0x1  /*  -   +   -   +  */
+#define TM_IPB			0x2  /*  -   +   +   +  */
+#define TM_LSMFB		0x3  /*  -   +   +   +  */
+#define TM_ACK_CNT		0x4  /*  -   +   -   -  */
+#define TM_INC			0x5  /*  -   +   -   +  */
+#define TM_AGE			0x6  /*  -   +   -   +  */
+#define TM_PIPR			0x7  /*  -   +   -   +  */
+
+#define TM_WORD0		0x0
+#define TM_WORD1		0x4
+
+/* QW word 2 contains the valid bit at the top and other fields
+ * depending on the QW
+ */
+#define TM_WORD2		0x8
+#define   TM_QW0W2_VU		PPC_BIT32(0)
+#define   TM_QW0W2_LOGIC_SERV	PPC_BITMASK32(1,31) // XX 2,31 ?
+#define   TM_QW1W2_VO		PPC_BIT32(0)
+#define   TM_QW1W2_OS_CAM	PPC_BITMASK32(8,31)
+#define   TM_QW2W2_VP		PPC_BIT32(0)
+#define   TM_QW2W2_POOL_CAM	PPC_BITMASK32(8,31)
+#define   TM_QW3W2_VT		PPC_BIT32(0)
+#define   TM_QW3W2_LP		PPC_BIT32(6)
+#define   TM_QW3W2_LE		PPC_BIT32(7)
+#define   TM_QW3W2_T		PPC_BIT32(31)
+
+/* In addition to normal loads to "peek" and writes (only when invalid)
+ * using 4 and 8 bytes accesses, the above registers support these
+ * "special" byte operations:
+ *
+ *   - Byte load from QW0[NSR] - User level NSR (EBB)
+ *   - Byte store to QW0[NSR] - User level NSR (EBB)
+ *   - Byte load/store to QW1[CPPR] and QW3[CPPR] - CPPR access
+ *   - Byte load from QW3[TM_WORD2] - Read VT||00000||LP||LE on thrd 0
+ *                                    otherwise VT||0000000
+ *   - Byte store to QW3[TM_WORD2] - Set VT bit (and LP/LE if present)
+ *
+ * Then we have all these "special" CI ops at these offset that trigger
+ * all sorts of side effects:
+ */
+#define TM_SPC_ACK_EBB		0x800	/* Load8 ack EBB to reg*/
+#define TM_SPC_ACK_OS_REG	0x810	/* Load16 ack OS irq to reg */
+#define TM_SPC_PUSH_USR_CTX	0x808	/* Store32 Push/Validate user context */
+#define TM_SPC_PULL_USR_CTX	0x808	/* Load32 Pull/Invalidate user context */
+#define TM_SPC_SET_OS_PENDING	0x812	/* Store8 Set OS irq pending bit */
+#define TM_SPC_PULL_OS_CTX	0x818	/* Load32/Load64 Pull/Invalidate OS context to reg */
+#define TM_SPC_PULL_POOL_CTX	0x828	/* Load32/Load64 Pull/Invalidate Pool context to reg*/
+#define TM_SPC_ACK_HV_REG	0x830	/* Load16 ack HV irq to reg */
+#define TM_SPC_PULL_USR_CTX_OL	0xc08	/* Store8 Pull/Inval usr ctx to odd line */
+#define TM_SPC_ACK_OS_EL	0xc10	/* Store8 ack OS irq to even line */
+#define TM_SPC_ACK_HV_POOL_EL	0xc20	/* Store8 ack HV evt pool to even line */
+#define TM_SPC_ACK_HV_EL	0xc30	/* Store8 ack HV irq to even line */
+/* XXX more... */
+
+/* NSR fields for the various QW ack types */
+#define TM_QW0_NSR_EB		PPC_BIT8(0)
+#define TM_QW1_NSR_EO		PPC_BIT8(0)
+#define TM_QW3_NSR_HE		PPC_BITMASK8(0,1)
+#define  TM_QW3_NSR_HE_NONE	0
+#define  TM_QW3_NSR_HE_POOL	1
+#define  TM_QW3_NSR_HE_PHYS	2
+#define  TM_QW3_NSR_HE_LSI	3
+#define TM_QW3_NSR_I		PPC_BIT8(2)
+#define TM_QW3_NSR_GRP_LVL	PPC_BIT8(3,7)
+
+/* Utilities to manipulate these (originaly from OPAL) */
+#define MASK_TO_LSH(m)		(__builtin_ffsl(m) - 1)
+#define GETFIELD(m, v)		(((v) & (m)) >> MASK_TO_LSH(m))
+#define SETFIELD(m, v, val)				\
+	(((v) & ~(m)) |	((((typeof(v))(val)) << MASK_TO_LSH(m)) & (m)))
+
+
+#endif /* __XIVE_H__ */
diff --git a/arch/powerpc/include/asm/xive.h b/arch/powerpc/include/asm/xive.h
new file mode 100644
index 0000000..53755e1
--- /dev/null
+++ b/arch/powerpc/include/asm/xive.h
@@ -0,0 +1,164 @@ 
+/*
+ * 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.
+ */
+#ifndef _ASM_POWERPC_XIVE_H
+#define _ASM_POWERPC_XIVE_H
+
+#define XIVE_INVALID_VP	0xffffffff
+
+#ifdef CONFIG_PPC_XIVE
+
+/*
+ * Thread Interrupt Management Area (TIMA)
+ *
+ * This is a global MMIO region divided in 4 pages of varying access
+ * permissions, providing access to per-cpu interrupt management
+ * functions. It always identifies the CPU doing the access based
+ * on the PowerBus initiator ID, thus we always access via the
+ * same offset regardless of where the code is executing
+ */
+extern void __iomem *xive_tima;
+
+/*
+ * Offset in the TM area of our current execution level (provided by
+ * the backend)
+ */
+extern u32 xive_tima_offset;
+
+/*
+ * Per-irq data (irq_get_handler_data for normal IRQs), IPIs
+ * have it stored in the xive_cpu structure. We also cache
+ * for normal interrupts the current target CPU.
+ *
+ * This structure is setup by the backend for each interrupt.
+ */
+struct xive_irq_data {
+	u64 flags;
+	u64 eoi_page;
+	void __iomem *eoi_mmio;
+	u64 trig_page;
+	void __iomem *trig_mmio;
+	u32 esb_shift;
+	int src_chip;
+
+	/* Setup/used by frontend */
+	int target;
+	bool saved_p;
+};
+#define XIVE_IRQ_FLAG_STORE_EOI	0x01
+#define XIVE_IRQ_FLAG_LSI	0x02
+#define XIVE_IRQ_FLAG_SHIFT_BUG	0x04
+#define XIVE_IRQ_FLAG_MASK_FW	0x08
+#define XIVE_IRQ_FLAG_EOI_FW	0x10
+
+#define XIVE_INVALID_CHIP_ID	-1
+
+/* A queue tracking structure in a CPU */
+struct xive_q {
+	__be32 			*qpage;
+	u32			msk;
+	u32			idx;
+	u32			toggle;
+	u64			eoi_phys;
+	u32			esc_irq;
+	atomic_t		count;
+	atomic_t		pending_count;
+};
+
+/*
+ * "magic" Event State Buffer (ESB) MMIO offsets.
+ *
+ * Each interrupt source has a 2-bit state machine called ESB
+ * which can be controlled by MMIO. It's made of 2 bits, P and
+ * Q. P indicates that an interrupt is pending (has been sent
+ * to a queue and is waiting for an EOI). Q indicates that the
+ * interrupt has been triggered while pending.
+ *
+ * This acts as a coalescing mechanism in order to guarantee
+ * that a given interrupt only occurs at most once in a queue.
+ *
+ * When doing an EOI, the Q bit will indicate if the interrupt
+ * needs to be re-triggered.
+ *
+ * The following offsets into the ESB MMIO allow to read or
+ * manipulate the PQ bits. They must be used with an 8-bytes
+ * load instruction. They all return the previous state of the
+ * interrupt (atomically).
+ *
+ * Additionally, some ESB pages support doing an EOI via a
+ * store at 0 and some ESBs support doing a trigger via a
+ * separate trigger page.
+ */
+#define XIVE_ESB_GET		0x800
+#define XIVE_ESB_SET_PQ_00	0xc00
+#define XIVE_ESB_SET_PQ_01	0xd00
+#define XIVE_ESB_SET_PQ_10	0xe00
+#define XIVE_ESB_SET_PQ_11	0xf00
+#define XIVE_ESB_MASK		XIVE_ESB_SET_PQ_01
+
+#define XIVE_ESB_VAL_P		0x2
+#define XIVE_ESB_VAL_Q		0x1
+
+/* Global enable flags for the XIVE support */
+extern bool __xive_enabled;
+
+static inline bool xive_enabled(void) { return __xive_enabled; }
+
+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_kexec_teardown_cpu(int secondary);
+extern void xive_shutdown(void);
+extern void xive_flush_interrupt(void);
+
+/* xmon hook */
+extern void xmon_xive_do_dump(int cpu);
+
+/* APIs used by KVM */
+extern u32 xive_native_default_eq_shift(void);
+extern u32 xive_native_alloc_vp_block(u32 max_vcpus);
+extern void xive_native_free_vp_block(u32 vp_base);
+extern int xive_native_populate_irq_data(u32 hw_irq,
+					 struct xive_irq_data *data);
+extern void xive_cleanup_irq_data(struct xive_irq_data *xd);
+extern u32 xive_native_alloc_irq(void);
+extern void xive_native_free_irq(u32 irq);
+extern int xive_native_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq);
+
+extern int xive_native_configure_queue(u32 vp_id, struct xive_q *q, u8 prio,
+				       __be32 *qpage, u32 order, bool can_escalate);
+extern void xive_native_disable_queue(u32 vp_id, struct xive_q *q, u8 prio);
+
+extern bool __xive_irq_trigger(struct xive_irq_data *xd);
+extern bool __xive_irq_retrigger(struct xive_irq_data *xd);
+extern void xive_do_source_eoi(u32 hw_irq, struct xive_irq_data *xd);
+
+extern bool is_xive_irq(struct irq_chip *chip);
+
+#else
+
+static inline bool xive_enabled(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; }
+static inline void xive_smp_setup_cpu(void) { }
+static inline void xive_smp_disable_cpu(void) { }
+static inline void xive_kexec_teardown_cpu(int secondary) { }
+static inline void xive_shutdown(void) { }
+static inline void xive_flush_interrupt(void) { }
+
+static inline u32 xive_native_alloc_vp_block(u32 max_vcpus)
+    { return XIVE_INVALID_VP; }
+static inline void xive_native_free_vp_block(u32 vp_base) { }
+
+#endif
+
+#endif /* _ASM_POWERPC_XIVE_H */
diff --git a/arch/powerpc/include/asm/xmon.h b/arch/powerpc/include/asm/xmon.h
index 5eb8e59..eb42a0c 100644
--- a/arch/powerpc/include/asm/xmon.h
+++ b/arch/powerpc/include/asm/xmon.h
@@ -29,5 +29,7 @@  static inline void xmon_register_spus(struct list_head *list) { };
 extern int cpus_are_in_xmon(void);
 #endif
 
+extern void xmon_printf(const char *format, ...);
+
 #endif /* __KERNEL __ */
 #endif /* __ASM_POWERPC_XMON_H */
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 4d6c64b..ae55603 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -23,6 +23,7 @@ 
 #include <asm/kvm_book3s.h>
 #include <asm/archrandom.h>
 #include <asm/xics.h>
+#include <asm/xive.h>
 #include <asm/dbell.h>
 #include <asm/cputhreads.h>
 #include <asm/io.h>
@@ -224,6 +225,10 @@  void kvmhv_rm_send_ipi(int cpu)
 		return;
 	}
 
+	/* We should never reach this */
+	if (WARN_ON_ONCE(xive_enabled()))
+	    return;
+
 	/* Else poke the target with an IPI */
 	xics_phys = paca[cpu].kvm_hstate.xics_phys;
 	if (xics_phys)
@@ -386,6 +391,9 @@  long kvmppc_read_intr(void)
 	long rc;
 	bool again;
 
+	if (xive_enabled())
+		return 1;
+
 	do {
 		again = false;
 		rc = kvmppc_read_one_intr(&again);
diff --git a/arch/powerpc/platforms/powernv/Kconfig b/arch/powerpc/platforms/powernv/Kconfig
index 3a07e4d..81ee2ed 100644
--- a/arch/powerpc/platforms/powernv/Kconfig
+++ b/arch/powerpc/platforms/powernv/Kconfig
@@ -4,6 +4,8 @@  config PPC_POWERNV
 	select PPC_NATIVE
 	select PPC_XICS
 	select PPC_ICP_NATIVE
+	select PPC_XIVE
+	select PPC_XIVE_NATIVE
 	select PPC_P7_NAP
 	select PCI
 	select PCI_MSI
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index d50c7d9..adceac9 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -32,6 +32,7 @@ 
 #include <asm/machdep.h>
 #include <asm/firmware.h>
 #include <asm/xics.h>
+#include <asm/xive.h>
 #include <asm/opal.h>
 #include <asm/kexec.h>
 #include <asm/smp.h>
@@ -76,7 +77,9 @@  static void __init pnv_init(void)
 
 static void __init pnv_init_IRQ(void)
 {
-	xics_init();
+	/* Try using a XIVE if available, otherwise use a XICS */
+	if (!xive_native_init())
+		xics_init();
 
 	WARN_ON(!ppc_md.get_irq);
 }
@@ -218,10 +221,12 @@  static void pnv_kexec_wait_secondaries_down(void)
 
 static void pnv_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);
 
 	/* On OPAL, we return all CPUs to firmware */
-
 	if (!firmware_has_feature(FW_FEATURE_OPAL))
 		return;
 
@@ -237,6 +242,10 @@  static void pnv_kexec_cpu_down(int crash_shutdown, int secondary)
 		/* Primary waits for the secondaries to have reached OPAL */
 		pnv_kexec_wait_secondaries_down();
 
+		/* Switch XIVE back to emulation mode */
+		if (xive_enabled())
+			xive_shutdown();
+
 		/*
 		 * We might be running as little-endian - now that interrupts
 		 * are disabled, reset the HILE bit to big-endian so we don't
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c
index 8b67e1e..f571955 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -29,6 +29,7 @@ 
 #include <asm/vdso_datapage.h>
 #include <asm/cputhreads.h>
 #include <asm/xics.h>
+#include <asm/xive.h>
 #include <asm/opal.h>
 #include <asm/runlatch.h>
 #include <asm/code-patching.h>
@@ -47,7 +48,9 @@ 
 
 static void pnv_smp_setup_cpu(int cpu)
 {
-	if (cpu != boot_cpuid)
+	if (xive_enabled())
+		xive_smp_setup_cpu();
+	else if (cpu != boot_cpuid)
 		xics_setup_cpu();
 
 #ifdef CONFIG_PPC_DOORBELL
@@ -132,7 +135,10 @@  static int pnv_smp_cpu_disable(void)
 	vdso_data->processorCount--;
 	if (cpu == boot_cpuid)
 		boot_cpuid = cpumask_any(cpu_online_mask);
-	xics_migrate_irqs_away();
+	if (xive_enabled())
+		xive_smp_disable_cpu();
+	else
+		xics_migrate_irqs_away();
 	return 0;
 }
 
@@ -213,9 +219,12 @@  static void pnv_smp_cpu_kill_self(void)
 		if (((srr1 & wmask) == SRR1_WAKEEE) ||
 		    ((srr1 & wmask) == SRR1_WAKEHVI) ||
 		    (local_paca->irq_happened & PACA_IRQ_EE)) {
-			if (cpu_has_feature(CPU_FTR_ARCH_300))
-				icp_opal_flush_interrupt();
-			else
+			if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+				if (xive_enabled())
+					xive_flush_interrupt();
+				else
+					icp_opal_flush_interrupt();
+			} else
 				icp_native_flush_interrupt();
 		} else if ((srr1 & wmask) == SRR1_WAKEHDBELL) {
 			unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER);
@@ -252,10 +261,26 @@  static int pnv_cpu_bootable(unsigned int nr)
 	return smp_generic_cpu_bootable(nr);
 }
 
+static int pnv_smp_prepare_cpu(int cpu)
+{
+	if (xive_enabled())
+		return xive_smp_prepare_cpu(cpu);
+	return 0;
+}
+
+static void __init pnv_smp_probe(void)
+{
+	if (xive_enabled())
+		xive_smp_probe();
+	else
+		xics_smp_probe();
+}
+
 static struct smp_ops_t pnv_smp_ops = {
 	.message_pass	= smp_muxed_ipi_message_pass,
-	.cause_ipi	= NULL,	/* Filled at runtime by xics_smp_probe() */
-	.probe		= xics_smp_probe,
+	.cause_ipi	= NULL, /* Filled at runtime by xi{cs,ve}_smp_probe() */
+	.probe		= pnv_smp_probe,
+	.prepare_cpu	= pnv_smp_prepare_cpu,
 	.kick_cpu	= pnv_smp_kick_cpu,
 	.setup_cpu	= pnv_smp_setup_cpu,
 	.cpu_bootable	= pnv_cpu_bootable,
diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig
index 52dc165..caf882e 100644
--- a/arch/powerpc/sysdev/Kconfig
+++ b/arch/powerpc/sysdev/Kconfig
@@ -28,6 +28,7 @@  config PPC_MSI_BITMAP
 	default y if PPC_POWERNV
 
 source "arch/powerpc/sysdev/xics/Kconfig"
+source "arch/powerpc/sysdev/xive/Kconfig"
 
 config PPC_SCOM
 	bool
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index a254824..c0ae11d 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -71,5 +71,6 @@  obj-$(CONFIG_PPC_EARLY_DEBUG_MEMCONS)	+= udbg_memcons.o
 subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
 
 obj-$(CONFIG_PPC_XICS)		+= xics/
+obj-$(CONFIG_PPC_XIVE)		+= xive/
 
 obj-$(CONFIG_GE_FPGA)		+= ge/
diff --git a/arch/powerpc/sysdev/xive/Kconfig b/arch/powerpc/sysdev/xive/Kconfig
new file mode 100644
index 0000000..c8816c8
--- /dev/null
+++ b/arch/powerpc/sysdev/xive/Kconfig
@@ -0,0 +1,7 @@ 
+config PPC_XIVE
+       def_bool n
+       select PPC_SMP_MUXED_IPI
+       select HARDIRQS_SW_RESEND
+
+config PPC_XIVE_NATIVE
+       def_bool n
diff --git a/arch/powerpc/sysdev/xive/Makefile b/arch/powerpc/sysdev/xive/Makefile
new file mode 100644
index 0000000..3fab303
--- /dev/null
+++ b/arch/powerpc/sysdev/xive/Makefile
@@ -0,0 +1,4 @@ 
+subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
+
+obj-y				+= common.o
+obj-$(CONFIG_PPC_XIVE_NATIVE)	+= native.o
diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
new file mode 100644
index 0000000..9bb70e3
--- /dev/null
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -0,0 +1,1276 @@ 
+/*
+ * 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/threads.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/debugfs.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/msi.h>
+
+#include <asm/prom.h>
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/irq.h>
+#include <asm/errno.h>
+#include <asm/xive.h>
+#include <asm/xive-regs.h>
+#include <asm/xmon.h>
+
+#include "xive-internal.h"
+
+#undef DEBUG_FLUSH
+#undef DEBUG_ALL
+
+#define DBG(fmt...)		pr_devel("XIVE: " fmt)
+
+#ifdef DEBUG_ALL
+#define DBG_VERBOSE(fmt...)	pr_devel("XIVE: " fmt)
+#else
+#define DBG_VERBOSE(fmt...)	do { } while(0)
+#endif
+
+bool __xive_enabled;
+bool xive_cmdline_disabled;
+
+/* We use only one priority for now */
+static u8 xive_irq_priority;
+
+/* TIMA */
+void __iomem *xive_tima;
+u32 xive_tima_offset;
+
+/* Backend ops */
+static const struct xive_ops *xive_ops;
+
+/* Our global interrupt domain */
+static struct irq_domain *xive_irq_domain;
+
+/* The IPIs all use the same logical irq number */
+static u32 xive_ipi_irq;
+
+/* Xive state for each CPU */
+static DEFINE_PER_CPU(struct xive_cpu *, xive_cpu);
+
+/*
+ * A "disabled" interrupt should never fire, to catch problems
+ * we set its logical number to this
+ */
+#define XIVE_BAD_IRQ		0x7fffffff
+#define XIVE_MAX_IRQ		(XIVE_BAD_IRQ - 1)
+
+/* An invalid CPU target */
+#define XIVE_INVALID_TARGET	(-1)
+
+/*
+ * Read the next entry in a queue, return its content if it's valid
+ * or 0 if there is no new entry.
+ *
+ * The queue pointer is moved forward unless "just_peek" is set
+ */
+static u32 xive_read_eq(struct xive_q *q, bool just_peek)
+{
+	u32 cur;
+
+	if (!q->qpage)
+		return 0;
+	cur = be32_to_cpup(q->qpage + q->idx);
+
+	/* Check valid bit (31) vs current toggle polarity */
+	if ((cur >> 31) == q->toggle)
+		return 0;
+
+	/* If consuming from the queue ... */
+	if (!just_peek) {
+		/* Next entry */
+		q->idx = (q->idx + 1) & q->msk;
+
+		/* Wrap around: flip valid toggle */
+		if (q->idx == 0)
+			q->toggle ^= 1;
+	}
+	/* Mask out the valid bit (31) */
+	return cur & 0x7fffffff;
+}
+
+/*
+ * Scans all the queue that may have interrupts in them
+ * (based on "pending_prio") in priority order until an
+ * interrupt is found or all the queues are empty.
+ *
+ * Then updates the CPPR (Current Processor Priority
+ * Register) based on the most favored interrupt found
+ * (0xff if none) and return what was found (0 if none).
+ *
+ * If just_peek is set, return the most favored pending
+ * interrupt if any but don't update the queue pointers.
+ *
+ * Note: This function can operate generically on any number
+ * of queues (up to 8). The current implementation of the XIVE
+ * driver only uses a single queue however.
+ *
+ * Note2: This will also "flush" "the pending_count" of a queue
+ * into the "count" when that queue is observed to be empty.
+ * This is used to keep track of the amount of interrupts
+ * targetting a queue. When an interrupt is moved away from
+ * a queue, we only decrement that queue count once the queue
+ * has been observed empty to avoid races.
+ */
+static u32 xive_scan_interrupts(struct xive_cpu *xc, bool just_peek)
+{
+	u32 irq = 0;
+	u8 prio;
+
+	/* Find highest pending priority */
+	while (xc->pending_prio != 0) {
+		struct xive_q *q;
+
+		prio = ffs(xc->pending_prio) - 1;
+		DBG_VERBOSE("scan_irq: trying prio %d\n", prio);
+
+		/* Try to fetch */
+		irq = xive_read_eq(&xc->queue[prio], just_peek);
+
+		/* Found something ? That's it */
+		if (irq)
+			break;
+
+		/* Clear pending bits */
+		xc->pending_prio &= ~(1 << prio);
+
+		/*
+		 * Check if the queue count needs adjusting due to
+		 * interrupts being moved away. See description of
+		 * xive_dec_target_count()
+		 */
+		q = &xc->queue[prio];
+		if (atomic_read(&q->pending_count)) {
+			int p = atomic_xchg(&q->pending_count, 0);
+			if (p) {
+				WARN_ON(p > atomic_read(&q->count));
+				atomic_sub(p, &q->count);
+			}
+		}
+	}
+
+	/* If nothing was found, set CPPR to 0xff */
+	if (irq == 0)
+		prio = 0xff;
+
+	/* Update HW CPPR to match if necessary */
+	if (prio != xc->cppr) {
+		DBG_VERBOSE("scan_irq: adjusting CPPR to %d\n", prio);
+		xc->cppr = prio;
+		out_8(xive_tima + xive_tima_offset + TM_CPPR, prio);
+	}
+
+	return irq;
+}
+
+/*
+ * This is used to perform the magic loads from an ESB
+ * described in xive.h
+ */
+static u8 xive_poke_esb(struct xive_irq_data *xd, u32 offset)
+{
+	u64 val;
+
+	/* Handle HW errata */
+	if (xd->flags & XIVE_IRQ_FLAG_SHIFT_BUG)
+		offset |= offset << 4;
+
+	val = in_be64(xd->eoi_mmio + offset);
+
+	return (u8)val;
+}
+
+#ifdef CONFIG_XMON
+static void xive_dump_eq(const char *name, struct xive_q *q)
+{
+	u32 i0, i1, idx;
+
+	if (!q->qpage)
+		return;
+	idx = q->idx;
+	i0 = be32_to_cpup(q->qpage + idx);
+	idx = (idx + 1) & q->msk;
+	i1 = be32_to_cpup(q->qpage + idx);
+	xmon_printf("  %s Q T=%d %08x %08x ...\n", name,
+		    q->toggle, i0, i1);
+}
+
+void xmon_xive_do_dump(int cpu)
+{
+	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+	u64 val;
+
+	xmon_printf("XIVE state for CPU %d:\n", cpu);
+	xmon_printf("  pp=%02x cppr=%02x\n", xc->pending_prio, xc->cppr);
+	xive_dump_eq("IRQ", &xc->queue[xive_irq_priority]);
+	val = xive_poke_esb(&xc->ipi_data, XIVE_ESB_GET);
+	xmon_printf("  IPI state: %x:%c%c\n", xc->hw_ipi,
+		    val & XIVE_ESB_VAL_P ? 'P' : 'p',
+		    val & XIVE_ESB_VAL_P ? 'Q' : 'q');
+}
+#endif /* CONFIG_XMON */
+
+static unsigned int xive_get_irq(void)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+	u32 irq;
+
+	/*
+	 * This can be called either as a result of a HW interrupt or
+	 * as a "replay" because EOI decided there was still something
+	 * in one of the queues.
+	 *
+	 * First we perform an ACK cycle in order to update our mask
+	 * of pending priorities. This will also have the effect of
+	 * updating the CPPR to the most favored pending interrupts.
+	 *
+	 * In the future, if we have a way to differenciate a first
+	 * entry (on HW interrupt) from a replay triggered by EOI,
+	 * we could skip this on replays unless we soft-mask tells us
+	 * that a new HW interrupt occurred.
+	 */
+	xive_ops->update_pending(xc);
+
+	DBG_VERBOSE("get_irq: pending=%02x\n", xc->pending_prio);
+
+	/* Scan our queue(s) for interrupts */
+	irq = xive_scan_interrupts(xc, false);
+
+	DBG_VERBOSE("get_irq: got irq 0x%x, new pending=0x%02x\n",
+	    irq, xc->pending_prio);
+
+	/* Return pending interrupt if any */
+	if (irq == XIVE_BAD_IRQ)
+		return 0;
+	return irq;
+}
+
+/*
+ * After EOI'ing an interrupt, we need to re-check the queue
+ * to see if another interrupt is pending since multiple
+ * interrupts can coalesce into a single notification to the
+ * CPU.
+ *
+ * If we find that there is indeed more in there, we call
+ * force_external_irq_replay() to make Linux synthetize an
+ * external interrupt on the next call to local_irq_restore().
+ */
+static void xive_do_queue_eoi(struct xive_cpu *xc)
+{
+	if (xive_scan_interrupts(xc, true) != 0) {
+		DBG_VERBOSE("eoi: pending=0x%02x\n", xc->pending_prio);
+		force_external_irq_replay();
+	}
+}
+
+/*
+ * EOI an interrupt at the source. There are several methods
+ * to do this depending on the HW version and source type
+ */
+void xive_do_source_eoi(u32 hw_irq, struct xive_irq_data *xd)
+{
+	/* If the XIVE supports the new "store EOI facility, use it */
+	if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
+		out_be64(xd->eoi_mmio, 0);
+	else if (hw_irq && xd->flags & XIVE_IRQ_FLAG_EOI_FW) {
+		/*
+		 * The FW told us to call it. This happens for some
+		 * interrupt sources that need additional HW whacking
+		 * beyond the ESB manipulation. For example LPC interrupts
+		 * on P9 DD1.0 need a latch to be clared in the LPC bridge
+		 * itself. The Firmware will take care of it.
+		 */
+		if (WARN_ON_ONCE(!xive_ops->eoi))
+			return;
+		xive_ops->eoi(hw_irq);
+	} else {
+		u8 eoi_val;
+
+		/*
+		 * Otherwise for EOI, we use the special MMIO that does
+		 * a clear of both P and Q and returns the old Q,
+		 * except for LSIs where we use the "EOI cycle" special
+		 * load.
+		 *
+		 * This allows us to then do a re-trigger if Q was set
+		 * rather than synthesizing an interrupt in software
+		 *
+		 * For LSIs, using the HW EOI cycle works around a problem
+		 * on P9 DD1 PHBs where the other ESB accesses don't work
+		 * properly.
+		 */
+		if (xd->flags & XIVE_IRQ_FLAG_LSI)
+			in_be64(xd->eoi_mmio);
+		else {
+			eoi_val = xive_poke_esb(xd, XIVE_ESB_SET_PQ_00);
+			DBG_VERBOSE("eoi_val=%x\n", offset, eoi_val);
+
+			/* Re-trigger if needed */
+			if ((eoi_val & XIVE_ESB_VAL_Q) && xd->trig_mmio)
+				out_be64(xd->trig_mmio, 0);
+		}
+	}
+}
+
+/* irq_chip eoi callback */
+static void xive_irq_eoi(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+
+	DBG_VERBOSE("eoi_irq: irq=%d [0x%lx] pending=%02x\n",
+		    d->irq, irqd_to_hwirq(d), xc->pending_prio);
+
+	/* EOI the source if it hasn't been disabled */
+	if (!irqd_irq_disabled(d))
+		xive_do_source_eoi(irqd_to_hwirq(d), xd);
+
+	/*
+	 * Clear saved_p to indicate that it's no longer occupying
+	 * a queue slot on the target queue
+	 */
+	xd->saved_p = false;
+
+	/* Check for more work in the queue */
+	xive_do_queue_eoi(xc);
+}
+
+/*
+ * Helper used to mask and unmask an interrupt source. This
+ * is only called for normal interrupts that do not require
+ * masking/unmasking via firmware.
+ */
+static void xive_do_source_set_mask(struct xive_irq_data *xd,
+				    bool mask)
+{
+	u64 val;
+
+	/*
+	 * If the interrupt had P set, it may be in a queue.
+	 *
+	 * We need to make sure we don't re-enable it until it
+	 * has been fetched from that queue and EOId. We keep
+	 * a copy of that P state and use it to restore the
+	 * ESB accordingly on unmask.
+	 */
+	if (mask) {
+		val = xive_poke_esb(xd, XIVE_ESB_SET_PQ_01);
+		xd->saved_p = !!(val & XIVE_ESB_VAL_P);
+	} else if (xd->saved_p)
+		xive_poke_esb(xd, XIVE_ESB_SET_PQ_10);
+	else
+		xive_poke_esb(xd, XIVE_ESB_SET_PQ_00);
+}
+
+/*
+ * Try to chose "cpu" as a new interrupt target. Increments
+ * the queue accounting for that target if it's not already
+ * full.
+ */
+static bool xive_try_pick_target(int cpu)
+{
+	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+	struct xive_q *q = &xc->queue[xive_irq_priority];
+	int max;
+
+	/* Calculate max number of interrupts in that queue.
+	 *
+	 * We leave a gap of 1 just in case...
+	 */
+	max = (q->msk + 1) - 1;
+	return !!atomic_add_unless(&q->count, 1, max);
+}
+
+/*
+ * Un-account an interrupt for a target CPU. We don't directly
+ * decrement q->count since the interrupt might still be present
+ * in the queue.
+ *
+ * Instead increment a separate counter "pending_count" which
+ * will be substracted from "count" later when that CPU observes
+ * the queue to be empty.
+ */
+static void xive_dec_target_count(int cpu)
+{
+	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+	struct xive_q *q = &xc->queue[xive_irq_priority];
+
+	if (WARN_ON(cpu < 0))
+		return;
+
+	/*
+	 * We increment the "pending count" which will be used
+	 * to decrement the target queue count whenever it's next
+	 * processed and found empty. This ensure that we don't
+	 * decrement while we still have the interrupt there
+	 * occupying a slot.
+	 */
+	atomic_inc(&q->pending_count);
+}
+
+/* Find a tentative CPU target in a CPU mask */
+static int xive_find_target_in_mask(const struct cpumask *mask,
+				    unsigned int fuzz)
+{
+	int cpu, first, num, i;
+
+	/* Pick up a starting point CPU in the mask based on  fuzz */
+	num = cpumask_weight(mask);
+	first = fuzz % num;
+
+	/* Locate it */
+	cpu = cpumask_first(mask);
+	for (i = 0; i < first; i++)
+		cpu = cpumask_next(cpu, mask);
+	first = cpu;
+
+	/*
+	 * Now go through the entire mask until we find a valid
+	 * target.
+	 */
+	for (;;) {
+		/*
+		 * We re-check online as the fallback case passes us
+		 * an untested affinity mask
+		 */
+		if (cpu_online(cpu) && xive_try_pick_target(cpu))
+			return cpu;
+		cpu = cpumask_next(cpu, mask);
+		if (cpu == first)
+			break;
+		/* Wrap around */
+		if (cpu >= nr_cpu_ids)
+			cpu = cpumask_first(mask);
+	}
+	return -1;
+}
+
+/*
+ * Pick a target CPU for an interrupt. This is done at
+ * startup or if the affinity is changed in a way that
+ * invalidates the current target.
+ */
+static int xive_pick_irq_target(struct irq_data *d,
+				const struct cpumask *affinity)
+{
+	static unsigned int fuzz;
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	cpumask_var_t mask;
+	int cpu = -1;
+
+	/*
+	 * If we have chip IDs, first we try to build a mask of
+	 * CPUs matching ther CPU and find a target in there
+	 */
+	if (xd->src_chip != XIVE_INVALID_CHIP_ID &&
+		zalloc_cpumask_var(&mask, GFP_ATOMIC)) {
+		/* Build a mask of matching chip IDs */
+		for_each_cpu_and(cpu, affinity, cpu_online_mask) {
+			struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+			if (xc->chip_id == xd->src_chip)
+				cpumask_set_cpu(cpu, mask);
+		}
+		/* Try to find a target */
+		if (!cpumask_empty(mask))
+			cpu = xive_find_target_in_mask(mask, fuzz++);
+		free_cpumask_var(mask);
+		if (cpu >= 0)
+			return cpu;
+		fuzz--;
+	}
+
+	/* No chip IDs, fallback to using the affinity mask */
+	return xive_find_target_in_mask(affinity, fuzz++);
+}
+
+static unsigned int xive_irq_startup(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+	int target, rc;
+
+	DBG("xive_irq_startup: irq %d [0x%x] data @%p\n",
+	    d->irq, hw_irq, d);
+
+#ifdef CONFIG_PCI_MSI
+	/*
+	 * The generic MSI code returns with the interrupt disabled on the
+	 * card, using the MSI mask bits. Firmware doesn't appear to unmask
+	 * at that level, so we do it here by hand.
+	 */
+	if (irq_data_get_msi_desc(d))
+		pci_msi_unmask_irq(d);
+#endif
+
+	/* Pick a target */
+	target = xive_pick_irq_target(d, irq_data_get_affinity_mask(d));
+	if (target == XIVE_INVALID_TARGET) {
+		/* Try again breaking affinity */
+		target = xive_pick_irq_target(d, cpu_online_mask);
+		if (target == XIVE_INVALID_TARGET)
+			return -ENXIO;
+		pr_warn("XIVE: irq %d started with broken affinity\n",
+			d->irq);
+	}
+	xd->target = target;
+
+	/*
+	 * Configure the logical number to be the Linux IRQ number
+	 * and set the target queue
+	 */
+	rc = xive_ops->configure_irq(hw_irq,
+				     get_hard_smp_processor_id(target),
+				     xive_irq_priority, d->irq);
+	if (rc)
+		return rc;
+
+	/* Unmask the ESB */
+	xive_do_source_set_mask(xd, false);
+
+	return 0;
+}
+
+static void xive_irq_shutdown(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+
+	DBG("xive_irq_shutdown: irq %d [0x%x] data @%p\n",
+	    d->irq, hw_irq, d);
+
+	if (WARN_ON(xd->target == XIVE_INVALID_TARGET))
+		return;
+
+	/* Mask the interrupt at the source */
+	xive_do_source_set_mask(xd, true);
+
+	/*
+	 * The above may have set saved_p. We clear it otherwise it
+	 * will prevent re-enabling later on. It is ok to forget the
+	 * fact that the interrupt might be in a queue because we are
+	 * accounting that already in xive_dec_target_count() and will
+	 * be re-routing it to a new queue with proper accounting when
+	 * it's started up again
+	 */
+	xd->saved_p = false;
+
+	/*
+	 * Mask the interrupt in HW in the IVT/EAS and set the number
+	 * to be the "bad" IRQ number
+	 */
+	xive_ops->configure_irq(hw_irq,
+				get_hard_smp_processor_id(xd->target),
+				0xff, XIVE_BAD_IRQ);
+
+	xive_dec_target_count(xd->target);
+	xd->target = XIVE_INVALID_TARGET;
+}
+
+static void xive_irq_unmask(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+
+	DBG("xive_irq_unmask: irq %d data @%p\n", d->irq, xd);
+
+	/*
+	 * This is a workaround for PCI LSI problems on P9, for
+	 * these, we call FW to set the mask. The problems might
+	 * be fixed by P9 DD2.0, if that is the case, firmware
+	 * will no longer set that flag.
+	 */
+	if (xd->flags & XIVE_IRQ_FLAG_MASK_FW) {
+		unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+		xive_ops->configure_irq(hw_irq,
+					get_hard_smp_processor_id(xd->target),
+					xive_irq_priority, d->irq);
+		return;
+	}
+
+	xive_do_source_set_mask(xd, false);
+}
+
+static void xive_irq_mask(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+
+	DBG("xive_irq_mask: irq %d data @%p\n", d->irq, xd);
+
+	/*
+	 * This is a workaround for PCI LSI problems on P9, for
+	 * these, we call OPAL to set the mask. The problems might
+	 * be fixed by P9 DD2.0, if that is the case, firmware
+	 * will no longer set that flag.
+	 */
+	if (xd->flags & XIVE_IRQ_FLAG_MASK_FW) {
+		unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+		xive_ops->configure_irq(hw_irq,
+					get_hard_smp_processor_id(xd->target),
+					0xff, d->irq);
+		return;
+	}
+
+	xive_do_source_set_mask(xd, true);
+}
+
+static int xive_irq_set_affinity(struct irq_data *d,
+				 const struct cpumask *cpumask,
+				 bool force)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+	u32 target, old_target;
+	int rc = 0;
+
+	DBG("xive_irq_set_affinity: irq %d\n", d->irq);
+
+	/* Is this valid ? */
+	if (cpumask_any_and(cpumask, cpu_online_mask) >= nr_cpu_ids)
+		return -EINVAL;
+
+	/* If existing target is already in the new mask, and is
+	 * online then do nothing.
+	 */
+	if (cpu_online(xd->target) &&
+	    cpumask_test_cpu(xd->target, cpumask))
+		return IRQ_SET_MASK_OK;
+
+	/* Pick a new target */
+	target = xive_pick_irq_target(d, cpumask);
+
+	/* No target found */
+	if (target == XIVE_INVALID_TARGET)
+		return -ENXIO;
+
+	old_target = xd->target;
+
+	rc = xive_ops->configure_irq(hw_irq,
+				     get_hard_smp_processor_id(target),
+				     xive_irq_priority, d->irq);
+	if (rc < 0) {
+		pr_err("XIVE: Error %d reconfiguring irq %d\n", rc, d->irq);
+		return rc;
+	}
+
+	DBG("  target: 0x%x\n", target);
+	xd->target = target;
+
+	/* Give up previous target */
+	if (old_target != XIVE_INVALID_TARGET)
+	    xive_dec_target_count(old_target);
+
+	return IRQ_SET_MASK_OK;
+}
+
+static int xive_irq_set_type(struct irq_data *d, unsigned int flow_type)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+
+	/*
+	 * We only support these. This has really no effect other than setting
+	 * the corresponding descriptor bits mind you but those will in turn
+	 * affect the resend function when re-enabling an edge interrupt.
+	 *
+	 * Set set the default to edge as explained in map().
+	 */
+	if (flow_type == IRQ_TYPE_DEFAULT || flow_type == IRQ_TYPE_NONE)
+		flow_type = IRQ_TYPE_EDGE_RISING;
+
+	if (flow_type != IRQ_TYPE_EDGE_RISING &&
+	    flow_type != IRQ_TYPE_LEVEL_LOW)
+		return -EINVAL;
+
+	irqd_set_trigger_type(d, flow_type);
+
+	/*
+	 * Double check it matches what the FW thinks
+	 *
+	 * NOTE: We don't know yet if the PAPR interface will provide
+	 * the LSI vs MSI information apart from the device-tree so
+	 * this check might have to move into an optional backend call
+	 * that is specific to the native backend
+	 */
+	if ((flow_type == IRQ_TYPE_LEVEL_LOW) !=
+	    !!(xd->flags & XIVE_IRQ_FLAG_LSI))
+		pr_warn("XIVE: Interrupt %d (HW 0x%x) type mismatch,"
+			" Linux says %s, FW says %s\n",
+			d->irq, (u32)irqd_to_hwirq(d),
+			(flow_type == IRQ_TYPE_LEVEL_LOW) ? "Level" : "Edge",
+			(xd->flags & XIVE_IRQ_FLAG_LSI) ? "Level" : "Edge");
+
+	return IRQ_SET_MASK_OK_NOCOPY;
+}
+
+static int xive_irq_retrigger(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+
+	/* This should be only for MSIs */
+	if (WARN_ON(xd->flags & XIVE_IRQ_FLAG_LSI))
+		return 0;
+
+	/*
+	 * To perform a retrigger, we first set the PQ bits to
+	 * 11, then perform an EOI.
+	 */
+	xive_poke_esb(xd, XIVE_ESB_SET_PQ_11);
+
+	/*
+	 * Note: We pass "0" to the hw_irq argument in order to
+	 * avoid calling into the backend EOI code which we don't
+	 * want to do in the case of a re-trigger. Backends typically
+	 * only do EOI for LSIs anyway.
+	 */
+	xive_do_source_eoi(0, xd);
+
+	return 1;
+}
+
+static struct irq_chip xive_irq_chip = {
+	.name = "XIVE-IRQ",
+	.irq_startup = xive_irq_startup,
+	.irq_shutdown = xive_irq_shutdown,
+	.irq_eoi = xive_irq_eoi,
+	.irq_mask = xive_irq_mask,
+	.irq_unmask = xive_irq_unmask,
+	.irq_set_affinity = xive_irq_set_affinity,
+	.irq_set_type = xive_irq_set_type,
+	.irq_retrigger = xive_irq_retrigger,
+};
+
+bool is_xive_irq(struct irq_chip *chip)
+{
+	return chip == &xive_irq_chip;
+}
+
+void xive_cleanup_irq_data(struct xive_irq_data *xd)
+{
+	if (xd->eoi_mmio) {
+		iounmap(xd->eoi_mmio);
+		if (xd->eoi_mmio == xd->trig_mmio)
+			xd->trig_mmio = NULL;
+		xd->eoi_mmio = NULL;
+	}
+	if (xd->trig_mmio) {
+		iounmap(xd->trig_mmio);
+		xd->trig_mmio = NULL;
+	}
+}
+
+static int xive_irq_alloc_data(unsigned int virq, irq_hw_number_t hw)
+{
+	struct xive_irq_data *xd;
+	int rc;
+
+	xd = kzalloc(sizeof(struct xive_irq_data), GFP_KERNEL);
+	if (!xd)
+		return -ENOMEM;
+	rc = xive_ops->populate_irq_data(hw, xd);
+	if (rc) {
+		kfree(xd);
+		return rc;
+	}
+	xd->target = XIVE_INVALID_TARGET;
+	irq_set_handler_data(virq, xd);
+
+	return 0;
+}
+
+static void xive_irq_free_data(unsigned int virq)
+{
+	struct xive_irq_data *xd = irq_get_handler_data(virq);
+
+	if (!xd)
+		return;
+	irq_set_handler_data(virq, NULL);
+	xive_cleanup_irq_data(xd);
+	kfree(xd);
+}
+
+#ifdef CONFIG_SMP
+
+static void xive_cause_ipi(int cpu, unsigned long msg)
+{
+	struct xive_cpu *xc;
+	struct xive_irq_data *xd;
+
+	xc = per_cpu(xive_cpu, cpu);
+
+	DBG_VERBOSE("IPI msg#%ld CPU %d -> %d (HW IRQ 0x%x)\n",
+		    msg, smp_processor_id(), cpu, xc->hw_ipi);
+
+	xd = &xc->ipi_data;
+	if (WARN_ON(!xd->trig_mmio))
+		return;
+	out_be64(xd->trig_mmio, 0);
+}
+
+static irqreturn_t xive_muxed_ipi_action(int irq, void *dev_id)
+{
+	return smp_ipi_demux();
+}
+
+static void xive_ipi_eoi(struct irq_data *d)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+
+	/* Handle possible race with unplug and drop stale IPIs */
+	if (!xc)
+		return;
+	xive_do_source_eoi(xc->hw_ipi, &xc->ipi_data);
+	xive_do_queue_eoi(xc);
+}
+
+static void xive_ipi_unmask(struct irq_data *d)
+{
+	/* Nothing to do, we never mask IPIs, but the callback
+	 * must exist
+	 */
+}
+
+static void xive_ipi_mask(struct irq_data *d)
+{
+	/* Nothing to do, we never mask IPIs, but the callback
+	 * must exist
+	 */
+}
+
+static struct irq_chip xive_ipi_chip = {
+	.name = "XIVE-IPI",
+	.irq_eoi = xive_ipi_eoi,
+	.irq_mask = xive_ipi_mask,
+	.irq_unmask = xive_ipi_unmask,
+};
+
+static void __init xive_request_ipi(void)
+{
+	unsigned int virq;
+
+	/*
+	 * Initialization failed, move on, we might manage to
+	 * reach the point where we display our errors before
+	 * the system falls appart
+	 */
+	if (!xive_irq_domain)
+		return;
+
+	/* Initialize it */
+	virq = irq_create_mapping(xive_irq_domain, 0);
+	xive_ipi_irq = virq;
+
+	WARN_ON(request_irq(virq, xive_muxed_ipi_action,
+			    IRQF_PERCPU | IRQF_NO_THREAD, "IPI", NULL));
+}
+
+static int xive_setup_cpu_ipi(unsigned int cpu)
+{
+	struct xive_cpu *xc;
+	int rc;
+
+	pr_debug("XIVE: Setting up IPI for CPU %d\n", cpu);
+
+	xc = per_cpu(xive_cpu, cpu);
+
+	/* Check if we are already setup */
+	if (xc->hw_ipi != 0)
+		return 0;
+
+	/* Grab an IPI from the backend, this will populate xc->hw_ipi */
+	if (xive_ops->get_ipi(cpu, xc))
+		return -EIO;
+
+	/* Populate the IRQ data in the xive_cpu structure and
+	 * configure the HW / enable the IPIs
+	 */
+	rc = xive_ops->populate_irq_data(xc->hw_ipi, &xc->ipi_data);
+	if (rc) {
+		pr_err("XIVE: Failed to populate IPI data on CPU %d\n", cpu);
+		return -EIO;
+	}
+	rc = xive_ops->configure_irq(xc->hw_ipi,
+				     get_hard_smp_processor_id(cpu),
+				     xive_irq_priority, xive_ipi_irq);
+	if (rc) {
+		pr_err("XIVE: Failed to map IPI CPU %d\n", cpu);
+		return -EIO;
+	}
+	DBG("XIVE: CPU %d HW IPI %x, virq %d, trig_mmio=%p\n", cpu,
+	    xc->hw_ipi, xive_ipi_irq, xc->ipi_data.trig_mmio);
+
+	/* Unmask it */
+	xive_do_source_set_mask(&xc->ipi_data, false);
+
+	return 0;
+}
+
+static void xive_cleanup_cpu_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+	/* Disable the IPI and free the IRQ data */
+
+	/* Already cleaned up ? */
+	if (xc->hw_ipi == 0)
+		return;
+
+	/* Mask the IPI */
+	xive_do_source_set_mask(&xc->ipi_data, true);
+
+	/*
+	 * Note: We don't call xive_cleanup_irq_data() to free
+	 * the mappings as this is called from an IPI on kexec
+	 * which is not a safe environment to call iounmap()
+	 */
+
+	/* Deconfigure/mask in the backend */
+	xive_ops->configure_irq(xc->hw_ipi, hard_smp_processor_id(),
+				0xff, xive_ipi_irq);
+
+	/* Free the IPIs in the backend */
+	xive_ops->put_ipi(cpu, xc);
+}
+
+void __init xive_smp_probe(void)
+{
+	smp_ops->cause_ipi = xive_cause_ipi;
+
+	/* Register the IPI */
+	xive_request_ipi();
+
+	/* Allocate and setup IPI for the boot CPU */
+	xive_setup_cpu_ipi(smp_processor_id());
+}
+
+#endif /* CONFIG_SMP */
+
+static int xive_irq_domain_map(struct irq_domain *h, unsigned int virq,
+			       irq_hw_number_t hw)
+{
+	int rc;
+
+	/*
+	 * Mark interrupts as edge sensitive by default so that resend
+	 * actually works. Will fix that up below if needed.
+	 */
+	irq_clear_status_flags(virq, IRQ_LEVEL);
+
+	/* IPIs are special and come up with HW number 0 */
+	if (hw == 0) {
+		/*
+		 * IPIs are marked per-cpu. We use separate HW interrupts under
+		 * the hood but associated with the same "linux" interrupt
+		 */
+		irq_set_chip_and_handler(virq, &xive_ipi_chip,
+					 handle_percpu_irq);
+		return 0;
+	}
+
+	rc = xive_irq_alloc_data(virq, hw);
+	if (rc)
+		return rc;
+
+	irq_set_chip_and_handler(virq, &xive_irq_chip, handle_fasteoi_irq);
+
+	return 0;
+}
+
+static void xive_irq_domain_unmap(struct irq_domain *d, unsigned int virq)
+{
+	struct irq_data *data = irq_get_irq_data(virq);
+	unsigned int hw_irq;
+
+	/* XXX Assign BAD number */
+	if (!data)
+		return;
+	hw_irq = (unsigned int)irqd_to_hwirq(data);
+	if (hw_irq)
+		xive_irq_free_data(virq);
+}
+
+static int xive_irq_domain_xlate(struct irq_domain *h, struct device_node *ct,
+				 const u32 *intspec, unsigned int intsize,
+				 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
+
+{
+	*out_hwirq = intspec[0];
+
+	/*
+	 * If intsize is at least 2, we look for the type in the second cell,
+	 * we assume the LSB indicates a level interrupt.
+	 */
+	if (intsize > 1) {
+		if (intspec[1] & 1)
+			*out_flags = IRQ_TYPE_LEVEL_LOW;
+		else
+			*out_flags = IRQ_TYPE_EDGE_RISING;
+	} else
+		*out_flags = IRQ_TYPE_LEVEL_LOW;
+
+	return 0;
+}
+
+static int xive_irq_domain_match(struct irq_domain *h, struct device_node *node,
+				 enum irq_domain_bus_token bus_token)
+{
+	return xive_ops->match(node);
+}
+
+static const struct irq_domain_ops xive_irq_domain_ops = {
+	.match = xive_irq_domain_match,
+	.map = xive_irq_domain_map,
+	.unmap = xive_irq_domain_unmap,
+	.xlate = xive_irq_domain_xlate,
+};
+
+static void __init xive_init_host(void)
+{
+	xive_irq_domain = irq_domain_add_nomap(NULL, XIVE_MAX_IRQ,
+					       &xive_irq_domain_ops, NULL);
+	if (WARN_ON(xive_irq_domain == NULL))
+		return;
+	irq_set_default_host(xive_irq_domain);
+}
+
+static void xive_cleanup_cpu_queues(unsigned int cpu, struct xive_cpu *xc)
+{
+	if (xc->queue[xive_irq_priority].qpage)
+		xive_ops->cleanup_queue(cpu, xc, xive_irq_priority);
+}
+
+static int xive_setup_cpu_queues(unsigned int cpu, struct xive_cpu *xc)
+{
+	int rc = 0;
+
+	/* We setup 1 queues for now with a 64k page */
+	if (!xc->queue[xive_irq_priority].qpage)
+		rc = xive_ops->setup_queue(cpu, xc, xive_irq_priority);
+
+	return rc;
+}
+
+static int xive_prepare_cpu(unsigned int cpu)
+{
+	struct xive_cpu *xc;
+
+	xc = per_cpu(xive_cpu, cpu);
+	if (!xc) {
+		struct device_node *np;
+
+		xc = kzalloc_node(sizeof(struct xive_cpu),
+				  GFP_KERNEL, cpu_to_node(cpu));
+		if (!xc)
+			return -ENOMEM;
+		np = of_get_cpu_node(cpu, NULL);
+		if (np)
+			xc->chip_id = of_get_ibm_chip_id(np);
+		of_node_put(np);
+
+		per_cpu(xive_cpu, cpu) = xc;
+	}
+
+	/* Setup EQs if not already */
+	return xive_setup_cpu_queues(cpu, xc);
+}
+
+static void xive_setup_cpu(void)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+
+	/* Debug: Dump the TM state */
+	DBG("CPU %d [HW 0x%02x] VT=%02x\n",
+	    smp_processor_id(), hard_smp_processor_id(),
+	    in_8(xive_tima + xive_tima_offset + TM_WORD2));
+
+	/* The backend might have additional things to do */
+	if (xive_ops->setup_cpu)
+		xive_ops->setup_cpu(smp_processor_id(), xc);
+
+	/* Set CPPR to 0xff to enable flow of interrupts */
+	xc->cppr = 0xff;
+	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0xff);
+}
+
+#ifdef CONFIG_SMP
+void xive_smp_setup_cpu(void)
+{
+	DBG("XIVE: SMP setup CPU %d\n", smp_processor_id());
+
+	/* This will have already been done on the boot CPU */
+	if (smp_processor_id() != boot_cpuid)
+		xive_setup_cpu();
+
+}
+
+int xive_smp_prepare_cpu(unsigned int cpu)
+{
+	int rc;
+
+	/* Allocate per-CPU data and queues */
+	rc = xive_prepare_cpu(cpu);
+	if (rc)
+		return rc;
+
+	/* Allocate and setup IPI for the new CPU */
+	return xive_setup_cpu_ipi(cpu);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void xive_flush_cpu_queue(unsigned int cpu, struct xive_cpu *xc)
+{
+	u32 irq;
+
+	/* We assume local irqs are disabled */
+	WARN_ON(!irqs_disabled());
+
+	/* Check what's already in the CPU queue */
+	while ((irq = xive_scan_interrupts(xc, false)) != 0) {
+		/*
+		 * We need to re-route that interrupt to its new destination.
+		 * First get and lock the descriptor
+		 */
+		struct irq_desc *desc = irq_to_desc(irq);
+		struct irq_data *d = irq_desc_get_irq_data(desc);
+		struct xive_irq_data *xd;
+		unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+
+		/*
+		 * Ignore anything that isn't a XIVE irq and ignore
+		 * IPIs, so can just be dropped.
+		 */
+		if (d->domain != xive_irq_domain || hw_irq == 0)
+			continue;
+
+		/*
+		 * The IRQ should have already been re-routed, it's just a
+		 * stale in the old queue, so re-trigger it in order to make
+		 * it reach is new destination.
+		 */
+#ifdef DEBUG_FLUSH
+		pr_info("CPU %d: Got irq %d while offline, re-sending...\n",
+			cpu, irq);
+#endif
+		raw_spin_lock(&desc->lock);
+		xd = irq_desc_get_handler_data(desc);
+
+		/* For LSIs, we EOI, this will cause a resend if it's
+		 * still asserted. Otherwise do an MSI retrigger
+		 */
+		if (xd->flags & XIVE_IRQ_FLAG_LSI)
+			xive_do_source_eoi(irqd_to_hwirq(d), xd);
+		else
+			xive_irq_retrigger(d);
+		raw_spin_unlock(&desc->lock);
+	}
+}
+
+void xive_smp_disable_cpu(void)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+	unsigned int cpu = smp_processor_id();
+
+	/* Migrate interrupts away from the CPU */
+	irq_migrate_all_off_this_cpu();
+
+	/* Set CPPR to 0 to disable flow of interrupts */
+	xc->cppr = 0;
+	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0);
+
+	/* Flush everything still in the queue */
+	xive_flush_cpu_queue(cpu, xc);
+
+	/* Re-enable CPPR  */
+	xc->cppr = 0xff;
+	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0xff);
+}
+
+void xive_flush_interrupt(void)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+	unsigned int cpu = smp_processor_id();
+
+	/* Called if an interrupt occurs while the CPU is hot unplugged */
+	xive_flush_cpu_queue(cpu, xc);
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+#endif /* CONFIG_SMP */
+
+void xive_kexec_teardown_cpu(int secondary)
+{
+	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);
+
+	/* Backend cleanup if any */
+	if (xive_ops->teardown_cpu)
+		xive_ops->teardown_cpu(cpu, xc);
+
+	/* Get rid of IPI */
+	xive_cleanup_cpu_ipi(cpu, xc);
+
+	/* Disable and free the queues */
+	xive_cleanup_cpu_queues(cpu, xc);
+}
+
+void xive_shutdown(void)
+{
+	xive_ops->shutdown();
+}
+
+bool xive_core_init(const struct xive_ops *ops, void __iomem *area, u32 offset,
+		    u8 max_prio)
+{
+	xive_tima = area;
+	xive_tima_offset = offset;
+	xive_ops = ops;
+	xive_irq_priority = max_prio;
+
+	ppc_md.get_irq = xive_get_irq;
+	__xive_enabled = true;
+
+	DBG("Initializing host..\n");
+	xive_init_host();
+
+	DBG("Initializing boot CPU..\n");
+
+	/* Allocate per-CPU data and queues */
+	xive_prepare_cpu(smp_processor_id());
+
+	/* Get ready for interrupts */
+	xive_setup_cpu();
+
+	pr_info("XIVE: Interrupt handling intialized with %s backend\n",
+		xive_ops->name);
+	pr_info("XIVE: Using priority %d for all interrupts\n", max_prio);
+
+	return true;
+}
+
+static int __init xive_off(char *arg)
+{
+	xive_cmdline_disabled = true;
+	return 0;
+}
+__setup("xive=off", xive_off);
diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c
new file mode 100644
index 0000000..f7e1ad4
--- /dev/null
+++ b/arch/powerpc/sysdev/xive/native.c
@@ -0,0 +1,643 @@ 
+/*
+ * 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/debugfs.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/delay.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/opal.h>
+
+#include "xive-internal.h"
+
+#define DBG(fmt...)	pr_devel("XIVE: " fmt)
+
+static u32 xive_provision_size;
+static u32 *xive_provision_chips;
+static u32 xive_provision_chip_count;
+static u32 xive_queue_shift;
+static u32 xive_pool_vps = XIVE_INVALID_VP;
+static struct kmem_cache *xive_provision_cache;
+
+int xive_native_populate_irq_data(u32 hw_irq, struct xive_irq_data *data)
+{
+	__be64 flags, eoi_page, trig_page;
+	__be32 esb_shift, src_chip;
+	u64 opal_flags;
+	s64 rc;
+
+	memset(data, 0, sizeof(*data));
+
+	rc = opal_xive_get_irq_info(hw_irq, &flags, &eoi_page, &trig_page,
+				    &esb_shift, &src_chip);
+	if (rc) {
+		pr_err("XIVE: opal_xive_get_irq_info(0x%x) returned %lld\n",
+		       hw_irq, rc);
+		return -EINVAL;
+	}
+
+	opal_flags = be64_to_cpu(flags);
+	if (opal_flags & OPAL_XIVE_IRQ_STORE_EOI)
+		data->flags |= XIVE_IRQ_FLAG_STORE_EOI;
+	if (opal_flags & OPAL_XIVE_IRQ_LSI)
+		data->flags |= XIVE_IRQ_FLAG_LSI;
+	if (opal_flags & OPAL_XIVE_IRQ_SHIFT_BUG)
+		data->flags |= XIVE_IRQ_FLAG_SHIFT_BUG;
+	if (opal_flags & OPAL_XIVE_IRQ_MASK_VIA_FW)
+		data->flags |= XIVE_IRQ_FLAG_MASK_FW;
+	if (opal_flags & OPAL_XIVE_IRQ_EOI_VIA_FW)
+		data->flags |= XIVE_IRQ_FLAG_EOI_FW;
+	data->eoi_page = be64_to_cpu(eoi_page);
+	data->trig_page = be64_to_cpu(trig_page);
+	data->esb_shift = be32_to_cpu(esb_shift);
+	data->src_chip = be32_to_cpu(src_chip);
+
+	data->eoi_mmio = ioremap(data->eoi_page, 1u << data->esb_shift);
+	if (!data->eoi_mmio) {
+		pr_err("XIVE: Failed to map EOI page for irq 0x%x\n", hw_irq);
+		return -ENOMEM;
+	}
+
+	if (!data->trig_page)
+		return 0;
+	if (data->trig_page == data->eoi_page) {
+		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("XIVE: Failed to map trigger page for irq 0x%x\n", hw_irq);
+		return -ENOMEM;
+	}
+	return 0;
+}
+
+int xive_native_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq)
+{
+	s64 rc;
+
+	for (;;) {
+		rc = opal_xive_set_irq_config(hw_irq, target, prio, sw_irq);
+		if (rc != OPAL_BUSY)
+			break;
+		msleep(1);
+	}
+	return rc == 0 ? 0 : -ENXIO;
+}
+
+/* This can be called multiple time to change a queue configuration */
+int xive_native_configure_queue(u32 vp_id, struct xive_q *q, u8 prio,
+				__be32 *qpage, u32 order, bool can_escalate)
+{
+	s64 rc = 0;
+	__be64 qeoi_page_be;
+	__be32 esc_irq_be;
+	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 = opal_xive_get_queue_info(vp_id, prio, NULL, NULL,
+				      &qeoi_page_be,
+				      &esc_irq_be,
+				      NULL);
+	if (rc) {
+		pr_err("XIVE: Error %lld getting queue info prio %d\n",
+		       rc, prio);
+		rc = -EIO;
+		goto fail;
+	}
+	q->eoi_phys = be64_to_cpu(qeoi_page_be);
+
+	/* Default flags */
+	flags = OPAL_XIVE_EQ_ALWAYS_NOTIFY | OPAL_XIVE_EQ_ENABLED;
+
+	/* Escalation needed ? */
+	if (can_escalate) {
+		q->esc_irq = be32_to_cpu(esc_irq_be);
+		flags |= OPAL_XIVE_EQ_ESCALATE;
+	}
+
+	/* Configure and enable the queue in HW */
+	for (;;) {
+		rc = opal_xive_set_queue_info(vp_id, prio, qpage_phys, order, flags);
+		if (rc != OPAL_BUSY)
+			break;
+		msleep(1);
+	}
+	if (rc) {
+		pr_err("XIVE: Error %lld setting queue for prio %d\n",
+		       rc, prio);
+		rc = -EIO;
+	} else {
+		/*
+		 * KVM code requires all of the above to be visible before
+		 * q->qpage is set due to how it manages IPI EOIs
+		 */
+		wmb();
+		q->qpage = qpage;
+	}
+ fail:
+	return rc;
+}
+
+static void __xive_native_disable_queue(u32 vp_id, struct xive_q *q, u8 prio)
+{
+	s64 rc;
+
+	/* Disable the queue in HW */
+	for (;;) {
+		rc = opal_xive_set_queue_info(vp_id, prio, 0, 0, 0);
+			break;
+		msleep(1);
+	}
+	if (rc)
+		pr_err("XIVE: Error %lld disabling queue for prio %d\n",
+		       rc, prio);
+}
+
+void xive_native_disable_queue(u32 vp_id, struct xive_q *q, u8 prio)
+{
+	__xive_native_disable_queue(vp_id, q, prio);
+}
+
+static int xive_native_setup_queue(unsigned int cpu, struct xive_cpu *xc, u8 prio)
+{
+	struct xive_q *q = &xc->queue[prio];
+	unsigned int alloc_order;
+	struct page *pages;
+	__be32 *qpage;
+
+	alloc_order = (xive_queue_shift > PAGE_SHIFT) ?
+		(xive_queue_shift - PAGE_SHIFT) : 0;
+	pages = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, alloc_order);
+	if (!pages)
+		return -ENOMEM;
+	qpage = (__be32 *)page_address(pages);
+	memset(qpage, 0, 1 << xive_queue_shift);
+	return xive_native_configure_queue(get_hard_smp_processor_id(cpu),
+					   q, prio, qpage, xive_queue_shift, false);
+}
+
+static void xive_native_cleanup_queue(unsigned int cpu, struct xive_cpu *xc, u8 prio)
+{
+	struct xive_q *q = &xc->queue[prio];
+	unsigned int alloc_order;
+
+	/*
+	 * We use the variant with no iounmap as this is called on exec
+	 * from an IPI and iounmap isn't safe
+	 */
+	__xive_native_disable_queue(get_hard_smp_processor_id(cpu), q, prio);
+	alloc_order = (xive_queue_shift > PAGE_SHIFT) ?
+		(xive_queue_shift - PAGE_SHIFT) : 0;
+	free_pages((unsigned long)q->qpage, alloc_order);
+	q->qpage = NULL;
+}
+
+static bool xive_native_match(struct device_node *node)
+{
+	return of_device_is_compatible(node, "ibm,opal-xive-vc");
+}
+
+#ifdef CONFIG_SMP
+static int xive_native_get_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+	struct device_node *np;
+	unsigned int chip_id;
+	s64 irq;
+
+	/* Find the chip ID */
+	np = of_get_cpu_node(cpu, NULL);
+	if (np) {
+		if (of_property_read_u32(np, "ibm,chip-id", &chip_id) < 0)
+			chip_id = 0;
+	}
+
+	/* Allocate an IPI and populate info about it */
+	for (;;) {
+		irq = opal_xive_allocate_irq(chip_id);
+		if (irq == OPAL_BUSY) {
+			msleep(1);
+			continue;
+		}
+		if (irq < 0) {
+			pr_err("XIVE: Failed to allocate IPI on CPU %d\n",
+			       cpu);
+			return -ENXIO;
+		}
+		xc->hw_ipi = irq;
+		break;
+	}
+	return 0;
+}
+
+u32 xive_native_alloc_irq(void)
+{
+	s64 rc;
+
+	for (;;) {
+		rc = opal_xive_allocate_irq(OPAL_XIVE_ANY_CHIP);
+		if (rc != OPAL_BUSY)
+			break;
+		msleep(1);
+	}
+	if (rc < 0)
+		return 0;
+	return rc;
+}
+
+void xive_native_free_irq(u32 irq)
+{
+	for (;;) {
+		s64 rc = opal_xive_free_irq(irq);
+		if (rc != OPAL_BUSY)
+			break;
+		msleep(1);
+	}
+}
+
+static void xive_native_put_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+	s64 rc;
+
+	/* Free the IPI */
+	if (!xc->hw_ipi)
+		return;
+	for (;;) {
+		rc = opal_xive_free_irq(xc->hw_ipi);
+		if (rc == OPAL_BUSY) {
+			msleep(1);
+			continue;
+		}
+		xc->hw_ipi = 0;
+		break;
+	}
+}
+#endif /* CONFIG_SMP */
+
+static void xive_native_shutdown(void)
+{
+	/* Switch the XIVE to emulation mode */
+	opal_xive_reset(OPAL_XIVE_MODE_EMU);
+}
+
+/*
+ * Perform an "ack" cycle on the current thread, thus
+ * grabbing the pending active priorities and updating
+ * the CPPR to the most favored one.
+ */
+static void xive_native_update_pending(struct xive_cpu *xc)
+{
+	u8 he, cppr;
+	u16 ack;
+
+	/* Perform the acknowledge hypervisor to register cycle */
+	ack = be16_to_cpu(__raw_readw(xive_tima + TM_SPC_ACK_HV_REG));
+
+	/* Synchronize subsequent queue accesses */
+	mb();
+
+	/*
+	 * Grab the CPPR and the "HE" field which indicates the source
+	 * of the hypervisor interrupt (if any)
+	 */
+	cppr = ack & 0xff;
+	he = GETFIELD(TM_QW3_NSR_HE, (ack >> 8));
+	switch(he) {
+	case TM_QW3_NSR_HE_NONE: /* Nothing to see here */
+		break;
+	case TM_QW3_NSR_HE_PHYS: /* Physical thread interrupt */
+		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("XIVE: 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;
+		break;
+	case TM_QW3_NSR_HE_POOL: /* HV Pool interrupt (unused) */
+	case TM_QW3_NSR_HE_LSI:  /* Legacy FW LSI (unused) */
+		pr_err("XIVE: CPU %d got unexpected interrupt type HE=%d\n",
+		       smp_processor_id(), he);
+		return;
+	}
+}
+
+static void xive_native_eoi(u32 hw_irq)
+{
+	/* Not normally used except if specific interrupts need
+	 * a workaround on EOI
+	 */
+	opal_int_eoi(hw_irq);
+}
+
+static void xive_native_setup_cpu(unsigned int cpu, struct xive_cpu *xc)
+{
+	s64 rc;
+	u32 vp;
+	__be64 vp_cam_be;
+	u64 vp_cam;
+
+	if (xive_pool_vps == XIVE_INVALID_VP)
+		return;
+
+	/* Enable the pool VP */
+	vp = xive_pool_vps + get_hard_smp_processor_id(cpu);
+	pr_debug("XIVE: CPU %d setting up pool VP 0x%x\n", cpu, vp);
+	for (;;) {
+		rc = opal_xive_set_vp_info(vp, OPAL_XIVE_VP_ENABLED, 0);
+		if (rc != OPAL_BUSY)
+			break;
+		msleep(1);
+	}
+	if (rc) {
+		pr_err("XIVE: Failed to enable pool VP on CPU %d\n", cpu);
+		return;
+	}
+
+	/* Grab it's CAM value */
+	rc = opal_xive_get_vp_info(vp, NULL, &vp_cam_be, NULL, NULL);
+	if (rc) {
+		pr_err("XIVE: Failed to get pool VP info CPU %d\n", cpu);
+		return;
+	}
+	vp_cam = be64_to_cpu(vp_cam_be);
+
+	pr_debug("XIVE: VP CAM = %llx\n", vp_cam);
+
+	/* Push it on the CPU (set LSMFB to 0xff to skip backlog scan) */
+	pr_debug("XIVE: (Old HW value: %08x)\n",
+		 in_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD2));
+	out_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD0, 0xff);
+	out_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD2,
+		 TM_QW2W2_VP | vp_cam);
+	pr_debug("XIVE: (New HW value: %08x)\n",
+		 in_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD2));
+}
+
+static void xive_native_teardown_cpu(unsigned int cpu, struct xive_cpu *xc)
+{
+	s64 rc;
+	u32 vp;
+
+	if (xive_pool_vps == XIVE_INVALID_VP)
+		return;
+
+	/* Pull the pool VP from the CPU */
+	in_be64(xive_tima + TM_SPC_PULL_POOL_CTX);
+
+	/* Disable it */
+	vp = xive_pool_vps + get_hard_smp_processor_id(cpu);
+	for (;;) {
+		rc = opal_xive_set_vp_info(vp, 0, 0);
+		if (rc != OPAL_BUSY)
+			break;
+		msleep(1);
+	}
+}
+
+static void xive_native_sync_source(u32 hw_irq)
+{
+	opal_xive_sync(XIVE_SYNC_EAS, hw_irq);
+}
+
+static const struct xive_ops xive_native_ops = {
+	.populate_irq_data	= xive_native_populate_irq_data,
+	.configure_irq		= xive_native_configure_irq,
+	.setup_queue		= xive_native_setup_queue,
+	.cleanup_queue		= xive_native_cleanup_queue,
+	.match			= xive_native_match,
+	.shutdown		= xive_native_shutdown,
+	.update_pending		= xive_native_update_pending,
+	.eoi			= xive_native_eoi,
+	.setup_cpu		= xive_native_setup_cpu,
+	.teardown_cpu		= xive_native_teardown_cpu,
+	.sync_source		= xive_native_sync_source,
+#ifdef CONFIG_SMP
+	.get_ipi		= xive_native_get_ipi,
+	.put_ipi		= xive_native_put_ipi,
+#endif /* CONFIG_SMP */
+	.name			= "native",
+};
+
+static bool xive_parse_provisioning(struct device_node *np)
+{
+	int rc;
+
+	if (of_property_read_u32(np, "ibm,xive-provision-page-size",
+				 &xive_provision_size) < 0)
+		return true;
+	rc = of_property_count_elems_of_size(np, "ibm,xive-provision-chips", 4);
+	if (rc < 0) {
+		pr_err("XIVE: Error %d getting provision chips array\n", rc);
+		return false;
+	}
+	xive_provision_chip_count = rc;
+	if (rc == 0)
+		return true;
+
+	xive_provision_chips = kzalloc(4 * xive_provision_chip_count,
+				       GFP_KERNEL);
+	if (WARN_ON(!xive_provision_chips))
+		return false;
+
+	rc = of_property_read_u32_array(np, "ibm,xive-provision-chips",
+					xive_provision_chips,
+					xive_provision_chip_count);
+	if (rc < 0) {
+		pr_err("XIVE: Error %d reading provision chips array\n", rc);
+		return false;
+	}
+
+	xive_provision_cache = kmem_cache_create("xive-provision",
+						 xive_provision_size,
+						 xive_provision_size,
+						 0, NULL);
+	if (!xive_provision_cache) {
+		pr_err("XIVE: Failed to allocate provision cache\n");
+		return false;
+	}
+	return true;
+}
+
+u32 xive_native_default_eq_shift(void)
+{
+	return xive_queue_shift;
+}
+
+bool xive_native_init(void)
+{
+	struct device_node *np;
+	struct resource r;
+	void __iomem *tima;
+	struct property *prop;
+	u8 max_prio = 7;
+	const __be32 *p;
+	u32 val;
+	s64 rc;
+
+	if (xive_cmdline_disabled)
+		return false;
+
+	DBG("xive_native_init()\n");
+	np = of_find_compatible_node(NULL, NULL, "ibm,opal-xive-pe");
+	if (!np) {
+		DBG("not found !\n");
+		return false;
+	}
+	DBG("Found %s\n", np->full_name);
+
+	/* Resource 1 is HV window */
+	if (of_address_to_resource(np, 1, &r)) {
+		pr_err("XIVE: Failed to get thread mgmnt area resource\n");
+		return false;
+	}
+	tima = ioremap(r.start, resource_size(&r));
+	if (!tima) {
+		pr_err("XIVE: Failed to map thread mgmnt area\n");
+		return false;
+	}
+
+	/* Read number of priorities */
+	if (of_property_read_u32(np, "ibm,xive-#priorities", &val) == 0)
+		max_prio = val - 1;
+
+	/* Iterate the EQ sizes and pick one */
+	of_property_for_each_u32(np, "ibm,xive-eq-sizes", prop, p, val) {
+		xive_queue_shift = val;
+		if (val == PAGE_SHIFT)
+			break;
+	}
+
+	/* Grab size of provisioning pages */
+	xive_parse_provisioning(np);
+
+	/* Switch the XIVE to exploitation mode */
+	rc = opal_xive_reset(OPAL_XIVE_MODE_EXPL);
+	if (rc) {
+		pr_err("XIVE: Switch to exploitation mode failed"
+		       " with error %lld\n", rc);
+		return false;
+	}
+
+	/* Initialize XIVE core with our backend */
+	if (!xive_core_init(&xive_native_ops, tima, TM_QW3_HV_PHYS,
+			    max_prio)) {
+		opal_xive_reset(OPAL_XIVE_MODE_EMU);
+		return false;
+	}
+	pr_info("XIVE: Using %dkB queues\n", 1 << (xive_queue_shift - 10));
+	return true;
+}
+
+static bool xive_native_provision_pages(void)
+{
+	u32 i;
+	void *p;
+
+	for (i = 0; i < xive_provision_chip_count; i++) {
+		u32 chip = xive_provision_chips[i];
+
+		/* XXX TODO: Try to make the allocation local to the node where
+		 * the chip reside
+		 */
+		p = kmem_cache_alloc(xive_provision_cache, GFP_KERNEL);
+		if (!p) {
+			pr_err("XIVE: Failed to allocate provisioning page\n");
+			return false;
+		}
+		opal_xive_donate_page(chip, __pa(p));
+	}
+	return true;
+}
+
+u32 xive_native_alloc_vp_block(u32 max_vcpus)
+{
+	s64 rc;
+	u32 order;
+
+	order = fls(max_vcpus) - 1;
+	if (max_vcpus > (1 << order))
+		order++;
+
+	pr_info("XIVE: VP block alloc, for max VCPUs %d"
+		" use order %d\n", max_vcpus, order);
+	for (;;) {
+		rc = opal_xive_alloc_vp_block(order);
+		switch (rc) {
+		case OPAL_BUSY:
+			msleep(1);
+			break;
+		case OPAL_XIVE_PROVISIONING:
+			if (!xive_native_provision_pages())
+				return XIVE_INVALID_VP;
+			break;
+		default:
+			if (rc < 0) {
+				pr_err("XIVE: OPAL failed to allocate VCPUs"
+				       " order %d, err %lld\n",
+				       order, rc);
+				return XIVE_INVALID_VP;
+			}
+			return rc;
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(xive_native_alloc_vp_block);
+
+void xive_native_free_vp_block(u32 vp_base)
+{
+	s64 rc;
+
+	if (vp_base == XIVE_INVALID_VP)
+		return;
+
+	rc = opal_xive_free_vp_block(vp_base);
+	if (rc < 0)
+		pr_warn("XIVE: OPAL error %lld freeing VP block\n", rc);
+}
+EXPORT_SYMBOL_GPL(xive_native_free_vp_block);
diff --git a/arch/powerpc/sysdev/xive/xive-internal.h b/arch/powerpc/sysdev/xive/xive-internal.h
new file mode 100644
index 0000000..6f880ce
--- /dev/null
+++ b/arch/powerpc/sysdev/xive/xive-internal.h
@@ -0,0 +1,61 @@ 
+/*
+ * 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.
+ */
+#ifndef __XIVE_INTERNAL_H
+#define __XIVE_INTERNAL_H
+
+/* Each CPU carry one of these with various per-CPU state */
+struct xive_cpu {
+#ifdef CONFIG_SMP
+	/* HW irq number and data of IPI */
+	u32 hw_ipi;
+	struct xive_irq_data ipi_data;
+#endif /* CONFIG_SMP */
+
+	int chip_id;
+
+	/* Queue datas. Only one is populated */
+#define XIVE_MAX_QUEUES	8
+	struct xive_q queue[XIVE_MAX_QUEUES];
+
+	/* Pending mask. Each bit corresponds to a priority that
+	 * potentially has pending interrupts
+	 */
+	u8 pending_prio;
+
+	/* Cache of HW CPPR */
+	u8 cppr;
+};
+
+/* Backend ops */
+struct xive_ops {
+	int	(*populate_irq_data)(u32 hw_irq, struct xive_irq_data *data);
+	int 	(*configure_irq)(u32 hw_irq, u32 target, u8 prio, u32 sw_irq);
+	int	(*setup_queue)(unsigned int cpu, struct xive_cpu *xc, u8 prio);
+	void	(*cleanup_queue)(unsigned int cpu, struct xive_cpu *xc, u8 prio);
+	void	(*setup_cpu)(unsigned int cpu, struct xive_cpu *xc);
+	void	(*teardown_cpu)(unsigned int cpu, struct xive_cpu *xc);
+	bool	(*match)(struct device_node *np);
+	void	(*shutdown)(void);
+
+	void	(*update_pending)(struct xive_cpu *xc);
+	void	(*eoi)(u32 hw_irq);
+	void	(*sync_source)(u32 hw_irq);
+#ifdef CONFIG_SMP
+	int	(*get_ipi)(unsigned int cpu, struct xive_cpu *xc);
+	void	(*put_ipi)(unsigned int cpu, struct xive_cpu *xc);
+#endif
+	const char *name;
+};
+
+bool xive_core_init(const struct xive_ops *ops, void __iomem *area, u32 offset,
+		    u8 max_prio);
+
+extern bool xive_cmdline_disabled;
+
+#endif /*  __XIVE_INTERNAL_H */
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 16321ad..ac9da12 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -48,7 +48,7 @@ 
 #include <asm/reg.h>
 #include <asm/debug.h>
 #include <asm/hw_breakpoint.h>
-
+#include <asm/xive.h>
 #include <asm/opal.h>
 #include <asm/firmware.h>
 
@@ -232,7 +232,13 @@  Commands:\n\
   "\
   dr	dump stream of raw bytes\n\
   dt	dump the tracing buffers (uses printk)\n\
-  e	print exception information\n\
+"
+#ifdef CONFIG_PPC_POWERNV
+"  dx#   dump xive on CPU\n\
+  dxi#  dump xive irq state\n\
+  dxa   dump xive on all CPUs\n"
+#endif
+"  e	print exception information\n\
   f	flush cache\n\
   la	lookup symbol+offset of specified address\n\
   ls	lookup address of specified symbol\n\
@@ -2338,6 +2344,81 @@  static void dump_pacas(void)
 }
 #endif
 
+#ifdef CONFIG_PPC_POWERNV
+static void dump_one_xive(int cpu)
+{
+	unsigned int hwid = get_hard_smp_processor_id(cpu);
+
+	opal_xive_dump(XIVE_DUMP_TM_HYP, hwid);
+	opal_xive_dump(XIVE_DUMP_TM_POOL, hwid);
+	opal_xive_dump(XIVE_DUMP_TM_OS, hwid);
+	opal_xive_dump(XIVE_DUMP_TM_USER, hwid);
+	opal_xive_dump(XIVE_DUMP_VP, hwid);
+	opal_xive_dump(XIVE_DUMP_EMU_STATE, hwid);
+
+	if (setjmp(bus_error_jmp) != 0) {
+		catch_memory_errors = 0;
+		printf("*** Error dumping xive on cpu %d\n", cpu);
+		return;
+	}
+
+	catch_memory_errors = 1;
+	sync();
+	xmon_xive_do_dump(cpu);
+	sync();
+	__delay(200);
+	catch_memory_errors = 0;
+}
+
+static void dump_all_xives(void)
+{
+	int cpu;
+
+	if (num_possible_cpus() == 0) {
+		printf("No possible cpus, use 'dx #' to dump individual cpus\n");
+		return;
+	}
+
+	for_each_possible_cpu(cpu)
+		dump_one_xive(cpu);
+}
+
+static void dump_one_xive_irq(u32 num)
+{
+	s64 rc;
+	__be64 vp;
+	u8 prio;
+	__be32 lirq;
+
+	rc = opal_xive_get_irq_config(num, &vp, &prio, &lirq);
+	xmon_printf("IRQ 0x%x config: vp=0x%llx prio=%d lirq=0x%x (rc=%lld)\n",
+		    num, be64_to_cpu(vp), prio, be32_to_cpu(lirq), rc);
+}
+
+static void dump_xives(void)
+{
+	unsigned long num;
+	int c;
+
+	c = inchar();
+	if (c == 'a') {
+		dump_all_xives();
+		return;
+	} else if (c == 'i') {
+		if (scanhex(&num))
+			dump_one_xive_irq(num);
+		return;
+	}
+
+	termch = c;	/* Put c back, it wasn't 'a' */
+
+	if (scanhex(&num))
+		dump_one_xive(num);
+	else
+		dump_one_xive(xmon_owner);
+}
+#endif /* CONFIG_PPC_POWERNV */
+
 static void dump_by_size(unsigned long addr, long count, int size)
 {
 	unsigned char temp[16];
@@ -2386,6 +2467,14 @@  dump(void)
 		return;
 	}
 #endif
+#ifdef CONFIG_PPC_POWERNV
+	if (c == 'x') {
+		xmon_start_pagination();
+		dump_xives();
+		xmon_end_pagination();
+		return;
+	}
+#endif
 
 	if (c == '\n')
 		termch = c;