Merge branch 'x86-mrst-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-mrst-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits)
  x86, mrst: Fix whitespace breakage in apb_timer.c
  x86, mrst: Fix APB timer per cpu clockevent
  x86, mrst: Remove X86_MRST dependency on PCI_IOAPIC
  x86, olpc: Use pci subarch init for OLPC
  x86, pci: Add arch_init to x86_init abstraction
  x86, mrst: Add Kconfig dependencies for Moorestown
  x86, pci: Exclude Moorestown PCI code if CONFIG_X86_MRST=n
  x86, numaq: Make CONFIG_X86_NUMAQ depend on CONFIG_PCI
  x86, pci: Add sanity check for PCI fixed bar probing
  x86, legacy_irq: Remove duplicate vector assigment
  x86, legacy_irq: Remove left over nr_legacy_irqs
  x86, mrst: Platform clock setup code
  x86, apbt: Moorestown APB system timer driver
  x86, mrst: Add vrtc platform data setup code
  x86, mrst: Add platform timer info parsing code
  x86, mrst: Fill in PCI functions in x86_init layer
  x86, mrst: Add dummy legacy pic to platform setup
  x86/PCI: Moorestown PCI support
  x86, ioapic: Add dummy ioapic functions
  x86, ioapic: Early enable ioapic for timer irq
  ...

Fixed up semantic conflict of new clocksources due to commit
17622339af25 ("clocksource: add argument to resume callback").

38 files changed, 1610 insertions, 162 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f15f37bfbd62..e98440371525 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -393,8 +393,12 @@ config X86_ELAN
 
 config X86_MRST
        bool "Moorestown MID platform"
+	depends on PCI
+	depends on PCI_GOANY
 	depends on X86_32
 	depends on X86_EXTENDED_PLATFORM
+	depends on X86_IO_APIC
+	select APB_TIMER
 	---help---
 	  Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 	  Internet Device(MID) platform. Moorestown consists of two chips:
@@ -429,6 +433,7 @@ config X86_32_NON_STANDARD
 config X86_NUMAQ
 	bool "NUMAQ (IBM/Sequent)"
 	depends on X86_32_NON_STANDARD
+	depends on PCI
 	select NUMA
 	select X86_MPPARSE
 	---help---
@@ -629,6 +634,16 @@ config HPET_EMULATE_RTC
 	def_bool y
 	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 
+config APB_TIMER
+       def_bool y if MRST
+       prompt "Langwell APB Timer Support" if X86_MRST
+       help
+         APB timer is the replacement for 8254, HPET on X86 MID platforms.
+         The APBT provides a stable time base on SMP
+         systems, unlike the TSC, but it is more expensive to access,
+         as it is off-chip. APB timers are always running regardless of CPU
+         C states, they are used as per CPU clockevent device when possible.
+
 # Mark as embedded because too many people got it wrong.
 # The code disables itself when not needed.
 config DMI
diff --git a/arch/x86/include/asm/apb_timer.h b/arch/x86/include/asm/apb_timer.h
new file mode 100644
index 000000000000..c74a2eebe570
--- /dev/null
+++ b/arch/x86/include/asm/apb_timer.h
@@ -0,0 +1,70 @@
+/*
+ * apb_timer.h: Driver for Langwell APB timer based on Synopsis DesignWare
+ *
+ * (C) Copyright 2009 Intel Corporation
+ * Author: Jacob Pan (jacob.jun.pan@intel.com)
+ *
+ * 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; version 2
+ * of the License.
+ *
+ * Note:
+ */
+
+#ifndef ASM_X86_APBT_H
+#define ASM_X86_APBT_H
+#include <linux/sfi.h>
+
+#ifdef CONFIG_APB_TIMER
+
+/* Langwell DW APB timer registers */
+#define APBTMR_N_LOAD_COUNT    0x00
+#define APBTMR_N_CURRENT_VALUE 0x04
+#define APBTMR_N_CONTROL       0x08
+#define APBTMR_N_EOI           0x0c
+#define APBTMR_N_INT_STATUS    0x10
+
+#define APBTMRS_INT_STATUS     0xa0
+#define APBTMRS_EOI            0xa4
+#define APBTMRS_RAW_INT_STATUS 0xa8
+#define APBTMRS_COMP_VERSION   0xac
+#define APBTMRS_REG_SIZE       0x14
+
+/* register bits */
+#define APBTMR_CONTROL_ENABLE  (1<<0)
+#define APBTMR_CONTROL_MODE_PERIODIC   (1<<1) /*1: periodic 0:free running */
+#define APBTMR_CONTROL_INT     (1<<2)
+
+/* default memory mapped register base */
+#define LNW_SCU_ADDR           0xFF100000
+#define LNW_EXT_TIMER_OFFSET   0x1B800
+#define APBT_DEFAULT_BASE      (LNW_SCU_ADDR+LNW_EXT_TIMER_OFFSET)
+#define LNW_EXT_TIMER_PGOFFSET         0x800
+
+/* APBT clock speed range from PCLK to fabric base, 25-100MHz */
+#define APBT_MAX_FREQ          50
+#define APBT_MIN_FREQ          1
+#define APBT_MMAP_SIZE         1024
+
+#define APBT_DEV_USED  1
+
+extern void apbt_time_init(void);
+extern struct clock_event_device *global_clock_event;
+extern unsigned long apbt_quick_calibrate(void);
+extern int arch_setup_apbt_irqs(int irq, int trigger, int mask, int cpu);
+extern void apbt_setup_secondary_clock(void);
+extern unsigned int boot_cpu_id;
+extern int disable_apbt_percpu;
+
+extern struct sfi_timer_table_entry *sfi_get_mtmr(int hint);
+extern void sfi_free_mtmr(struct sfi_timer_table_entry *mtmr);
+extern int sfi_mtimer_num;
+
+#else /* CONFIG_APB_TIMER */
+
+static inline unsigned long apbt_quick_calibrate(void) {return 0; }
+static inline void apbt_time_init(void) {return 0; }
+
+#endif
+#endif /* ASM_X86_APBT_H */
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index eeac829a0f44..a929c9ede33d 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -53,13 +53,6 @@ extern void threshold_interrupt(void);
 extern void call_function_interrupt(void);
 extern void call_function_single_interrupt(void);
 
-/* PIC specific functions */
-extern void disable_8259A_irq(unsigned int irq);
-extern void enable_8259A_irq(unsigned int irq);
-extern int i8259A_irq_pending(unsigned int irq);
-extern void make_8259A_irq(unsigned int irq);
-extern void init_8259A(int aeoi);
-
 /* IOAPIC */
 #define IO_APIC_IRQ(x) (((x) >= NR_IRQS_LEGACY) || ((1<<(x)) & io_apic_irqs))
 extern unsigned long io_apic_irqs;
diff --git a/arch/x86/include/asm/i8259.h b/arch/x86/include/asm/i8259.h
index 7ec65b18085d..1655147646aa 100644
--- a/arch/x86/include/asm/i8259.h
+++ b/arch/x86/include/asm/i8259.h
@@ -26,11 +26,6 @@ extern unsigned int cached_irq_mask;
 
 extern raw_spinlock_t i8259A_lock;
 
-extern void init_8259A(int auto_eoi);
-extern void enable_8259A_irq(unsigned int irq);
-extern void disable_8259A_irq(unsigned int irq);
-extern unsigned int startup_8259A_irq(unsigned int irq);
-
 /* the PIC may need a careful delay on some platforms, hence specific calls */
 static inline unsigned char inb_pic(unsigned int port)
 {
@@ -57,7 +52,17 @@ static inline void outb_pic(unsigned char value, unsigned int port)
 
 extern struct irq_chip i8259A_chip;
 
-extern void mask_8259A(void);
-extern void unmask_8259A(void);
+struct legacy_pic {
+	int nr_legacy_irqs;
+	struct irq_chip *chip;
+	void (*mask_all)(void);
+	void (*restore_mask)(void);
+	void (*init)(int auto_eoi);
+	int (*irq_pending)(unsigned int irq);
+	void (*make_irq)(unsigned int irq);
+};
+
+extern struct legacy_pic *legacy_pic;
+extern struct legacy_pic null_legacy_pic;
 
 #endif /* _ASM_X86_I8259_H */
diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 5f61f6e0ffdd..35832a03a515 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -143,8 +143,6 @@ extern int noioapicreroute;
 /* 1 if the timer IRQ uses the '8259A Virtual Wire' mode */
 extern int timer_through_8259;
 
-extern void io_apic_disable_legacy(void);
-
 /*
  * If we use the IO-APIC for IRQ routing, disable automatic
  * assignment of PCI IRQ's.
@@ -189,6 +187,7 @@ extern struct mp_ioapic_gsi  mp_gsi_routing[];
 int mp_find_ioapic(int gsi);
 int mp_find_ioapic_pin(int ioapic, int gsi);
 void __init mp_register_ioapic(int id, u32 address, u32 gsi_base);
+extern void __init pre_init_apic_IRQ0(void);
 
 #else  /* !CONFIG_X86_IO_APIC */
 
@@ -198,7 +197,11 @@ static const int timer_through_8259 = 0;
 static inline void ioapic_init_mappings(void)	{ }
 static inline void ioapic_insert_resources(void) { }
 static inline void probe_nr_irqs_gsi(void)	{ }
+static inline int mp_find_ioapic(int gsi) { return 0; }
 
+struct io_apic_irq_attr;
+static inline int io_apic_set_pci_routing(struct device *dev, int irq,
+		 struct io_apic_irq_attr *irq_attr) { return 0; }
 #endif
 
 #endif /* _ASM_X86_IO_APIC_H */
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 262292729fc4..5458380b6ef8 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -48,6 +48,5 @@ extern DECLARE_BITMAP(used_vectors, NR_VECTORS);
 extern int vector_used_by_percpu_irq(unsigned int vector);
 
 extern void init_ISA_irqs(void);
-extern int nr_legacy_irqs;
 
 #endif /* _ASM_X86_IRQ_H */
diff --git a/arch/x86/include/asm/mrst.h b/arch/x86/include/asm/mrst.h
new file mode 100644
index 000000000000..451d30e7f62d
--- /dev/null
+++ b/arch/x86/include/asm/mrst.h
@@ -0,0 +1,19 @@
+/*
+ * mrst.h: Intel Moorestown platform specific setup code
+ *
+ * (C) Copyright 2009 Intel 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; version 2
+ * of the License.
+ */
+#ifndef _ASM_X86_MRST_H
+#define _ASM_X86_MRST_H
+extern int pci_mrst_init(void);
+int __init sfi_parse_mrtc(struct sfi_table_header *table);
+
+#define SFI_MTMR_MAX_NUM 8
+#define SFI_MRTC_MAX	8
+
+#endif /* _ASM_X86_MRST_H */
diff --git a/arch/x86/include/asm/numaq.h b/arch/x86/include/asm/numaq.h
index 13370b95ea94..37c516545ec8 100644
--- a/arch/x86/include/asm/numaq.h
+++ b/arch/x86/include/asm/numaq.h
@@ -30,6 +30,7 @@
 
 extern int found_numaq;
 extern int get_memcfg_numaq(void);
+extern int pci_numaq_init(void);
 
 extern void *xquad_portio;
 
diff --git a/arch/x86/include/asm/olpc.h b/arch/x86/include/asm/olpc.h
index 3a57385d9fa7..101229b0d8ed 100644
--- a/arch/x86/include/asm/olpc.h
+++ b/arch/x86/include/asm/olpc.h
@@ -13,7 +13,6 @@ struct olpc_platform_t {
 
 #define OLPC_F_PRESENT		0x01
 #define OLPC_F_DCON		0x02
-#define OLPC_F_VSA		0x04
 
 #ifdef CONFIG_OLPC
 
@@ -51,18 +50,6 @@ static inline int olpc_has_dcon(void)
 }
 
 /*
- * The VSA is software from AMD that typical Geode bioses will include.
- * It is used to emulate the PCI bus, VGA, etc.  OLPC's Open Firmware does
- * not include the VSA; instead, PCI is emulated by the kernel.
- *
- * The VSA is described further in arch/x86/pci/olpc.c.
- */
-static inline int olpc_has_vsa(void)
-{
-	return (olpc_platform_info.flags & OLPC_F_VSA) ? 1 : 0;
-}
-
-/*
  * The "Mass Production" version of OLPC's XO is identified as being model
  * C2.  During the prototype phase, the following models (in chronological
  * order) were created: A1, B1, B2, B3, B4, C1.  The A1 through B2 models
@@ -87,13 +74,10 @@ static inline int olpc_has_dcon(void)
 	return 0;
 }
 
-static inline int olpc_has_vsa(void)
-{
-	return 0;
-}
-
 #endif
 
+extern int pci_olpc_init(void);
+
 /* EC related functions */
 
 extern int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index b4a00dd4eed5..3e002ca5a287 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -45,8 +45,15 @@ static inline int pci_proc_domain(struct pci_bus *bus)
 
 #ifdef CONFIG_PCI
 extern unsigned int pcibios_assign_all_busses(void);
+extern int pci_legacy_init(void);
+# ifdef CONFIG_ACPI
+#  define x86_default_pci_init pci_acpi_init
+# else
+#  define x86_default_pci_init pci_legacy_init
+# endif
 #else
-#define pcibios_assign_all_busses()	0
+# define pcibios_assign_all_busses()	0
+# define x86_default_pci_init		NULL
 #endif
 
 extern unsigned long pci_mem_start;
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index 05b58ccb2e82..1a0422348d6d 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -83,7 +83,6 @@ struct irq_routing_table {
 
 extern unsigned int pcibios_irq_mask;
 
-extern int pcibios_scanned;
 extern spinlock_t pci_config_lock;
 
 extern int (*pcibios_enable_irq)(struct pci_dev *dev);
@@ -106,16 +105,15 @@ extern bool port_cf9_safe;
 extern int pci_direct_probe(void);
 extern void pci_direct_init(int type);
 extern void pci_pcbios_init(void);
-extern int pci_olpc_init(void);
 extern void __init dmi_check_pciprobe(void);
 extern void __init dmi_check_skip_isa_align(void);
 
 /* some common used subsys_initcalls */
 extern int __init pci_acpi_init(void);
-extern int __init pcibios_irq_init(void);
-extern int __init pci_visws_init(void);
-extern int __init pci_numaq_init(void);
+extern void __init pcibios_irq_init(void);
 extern int __init pcibios_init(void);
+extern int pci_legacy_init(void);
+extern void pcibios_fixup_irqs(void);
 
 /* pci-mmconfig.c */
 
@@ -183,3 +181,17 @@ static inline void mmio_config_writel(void __iomem *pos, u32 val)
 {
 	asm volatile("movl %%eax,(%1)" : : "a" (val), "r" (pos) : "memory");
 }
+
+#ifdef CONFIG_PCI
+# ifdef CONFIG_ACPI
+#  define x86_default_pci_init		pci_acpi_init
+# else
+#  define x86_default_pci_init		pci_legacy_init
+# endif
+# define x86_default_pci_init_irq	pcibios_irq_init
+# define x86_default_pci_fixup_irqs	pcibios_fixup_irqs
+#else
+# define x86_default_pci_init		NULL
+# define x86_default_pci_init_irq	NULL
+# define x86_default_pci_fixup_irqs	NULL
+#endif
diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
index 18e496c98ff0..86b1506f4179 100644
--- a/arch/x86/include/asm/setup.h
+++ b/arch/x86/include/asm/setup.h
@@ -37,10 +37,8 @@ void setup_bios_corruption_check(void);
 
 #ifdef CONFIG_X86_VISWS
 extern void visws_early_detect(void);
-extern int is_visws_box(void);
 #else
 static inline void visws_early_detect(void) { }
-static inline int is_visws_box(void) { return 0; }
 #endif
 
 extern unsigned long saved_video_mode;
diff --git a/arch/x86/include/asm/visws/cobalt.h b/arch/x86/include/asm/visws/cobalt.h
index 166adf61e770..2edb37637ead 100644
--- a/arch/x86/include/asm/visws/cobalt.h
+++ b/arch/x86/include/asm/visws/cobalt.h
@@ -122,4 +122,6 @@ extern char visws_board_type;
 
 extern char visws_board_rev;
 
+extern int pci_visws_init(void);
+
 #endif /* _ASM_X86_VISWS_COBALT_H */
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index 60cc35269083..519b54327d75 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -99,6 +99,20 @@ struct x86_init_iommu {
 };
 
 /**
+ * struct x86_init_pci - platform specific pci init functions
+ * @arch_init:			platform specific pci arch init call
+ * @init:			platform specific pci subsystem init
+ * @init_irq:			platform specific pci irq init
+ * @fixup_irqs:			platform specific pci irq fixup
+ */
+struct x86_init_pci {
+	int (*arch_init)(void);
+	int (*init)(void);
+	void (*init_irq)(void);
+	void (*fixup_irqs)(void);
+};
+
+/**
  * struct x86_init_ops - functions for platform specific setup
  *
  */
@@ -110,6 +124,7 @@ struct x86_init_ops {
 	struct x86_init_paging		paging;
 	struct x86_init_timers		timers;
 	struct x86_init_iommu		iommu;
+	struct x86_init_pci		pci;
 };
 
 /**
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index d87f09bc5a52..4c58352209e0 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -87,6 +87,7 @@ obj-$(CONFIG_VM86)		+= vm86_32.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
 obj-$(CONFIG_HPET_TIMER) 	+= hpet.o
+obj-$(CONFIG_APB_TIMER)		+= apb_timer.o
 
 obj-$(CONFIG_K8_NB)		+= k8.o
 obj-$(CONFIG_DEBUG_RODATA_TEST)	+= test_rodata.o
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 738fcb60e708..a54d714545ff 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -35,6 +35,7 @@
 #include <linux/ioport.h>
 #include <linux/pci.h>
 
+#include <asm/pci_x86.h>
 #include <asm/pgtable.h>
 #include <asm/io_apic.h>
 #include <asm/apic.h>
@@ -1624,6 +1625,9 @@ int __init acpi_boot_init(void)
 
 	acpi_table_parse(ACPI_SIG_HPET, acpi_parse_hpet);
 
+	if (!acpi_noirq)
+		x86_init.pci.init = pci_acpi_init;
+
 	return 0;
 }
 
diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c
new file mode 100644
index 000000000000..4b7099526d2c
--- /dev/null
+++ b/arch/x86/kernel/apb_timer.c
@@ -0,0 +1,784 @@
+/*
+ * apb_timer.c: Driver for Langwell APB timers
+ *
+ * (C) Copyright 2009 Intel Corporation
+ * Author: Jacob Pan (jacob.jun.pan@intel.com)
+ *
+ * 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; version 2
+ * of the License.
+ *
+ * Note:
+ * Langwell is the south complex of Intel Moorestown MID platform. There are
+ * eight external timers in total that can be used by the operating system.
+ * The timer information, such as frequency and addresses, is provided to the
+ * OS via SFI tables.
+ * Timer interrupts are routed via FW/HW emulated IOAPIC independently via
+ * individual redirection table entries (RTE).
+ * Unlike HPET, there is no master counter, therefore one of the timers are
+ * used as clocksource. The overall allocation looks like:
+ *  - timer 0 - NR_CPUs for per cpu timer
+ *  - one timer for clocksource
+ *  - one timer for watchdog driver.
+ * It is also worth notice that APB timer does not support true one-shot mode,
+ * free-running mode will be used here to emulate one-shot mode.
+ * APB timer can also be used as broadcast timer along with per cpu local APIC
+ * timer, but by default APB timer has higher rating than local APIC timers.
+ */
+
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/sysdev.h>
+#include <linux/pm.h>
+#include <linux/pci.h>
+#include <linux/sfi.h>
+#include <linux/interrupt.h>
+#include <linux/cpu.h>
+#include <linux/irq.h>
+
+#include <asm/fixmap.h>
+#include <asm/apb_timer.h>
+
+#define APBT_MASK			CLOCKSOURCE_MASK(32)
+#define APBT_SHIFT			22
+#define APBT_CLOCKEVENT_RATING		150
+#define APBT_CLOCKSOURCE_RATING		250
+#define APBT_MIN_DELTA_USEC		200
+
+#define EVT_TO_APBT_DEV(evt) container_of(evt, struct apbt_dev, evt)
+#define APBT_CLOCKEVENT0_NUM   (0)
+#define APBT_CLOCKEVENT1_NUM   (1)
+#define APBT_CLOCKSOURCE_NUM   (2)
+
+static unsigned long apbt_address;
+static int apb_timer_block_enabled;
+static void __iomem *apbt_virt_address;
+static int phy_cs_timer_id;
+
+/*
+ * Common DW APB timer info
+ */
+static uint64_t apbt_freq;
+
+static void apbt_set_mode(enum clock_event_mode mode,
+			  struct clock_event_device *evt);
+static int apbt_next_event(unsigned long delta,
+			   struct clock_event_device *evt);
+static cycle_t apbt_read_clocksource(struct clocksource *cs);
+static void apbt_restart_clocksource(struct clocksource *cs);
+
+struct apbt_dev {
+	struct clock_event_device evt;
+	unsigned int num;
+	int cpu;
+	unsigned int irq;
+	unsigned int tick;
+	unsigned int count;
+	unsigned int flags;
+	char name[10];
+};
+
+int disable_apbt_percpu __cpuinitdata;
+
+static DEFINE_PER_CPU(struct apbt_dev, cpu_apbt_dev);
+
+#ifdef CONFIG_SMP
+static unsigned int apbt_num_timers_used;
+static struct apbt_dev *apbt_devs;
+#endif
+
+static	inline unsigned long apbt_readl_reg(unsigned long a)
+{
+	return readl(apbt_virt_address + a);
+}
+
+static inline void apbt_writel_reg(unsigned long d, unsigned long a)
+{
+	writel(d, apbt_virt_address + a);
+}
+
+static inline unsigned long apbt_readl(int n, unsigned long a)
+{
+	return readl(apbt_virt_address + a + n * APBTMRS_REG_SIZE);
+}
+
+static inline void apbt_writel(int n, unsigned long d, unsigned long a)
+{
+	writel(d, apbt_virt_address + a + n * APBTMRS_REG_SIZE);
+}
+
+static inline void apbt_set_mapping(void)
+{
+	struct sfi_timer_table_entry *mtmr;
+
+	if (apbt_virt_address) {
+		pr_debug("APBT base already mapped\n");
+		return;
+	}
+	mtmr = sfi_get_mtmr(APBT_CLOCKEVENT0_NUM);
+	if (mtmr == NULL) {
+		printk(KERN_ERR "Failed to get MTMR %d from SFI\n",
+		       APBT_CLOCKEVENT0_NUM);
+		return;
+	}
+	apbt_address = (unsigned long)mtmr->phys_addr;
+	if (!apbt_address) {
+		printk(KERN_WARNING "No timer base from SFI, use default\n");
+		apbt_address = APBT_DEFAULT_BASE;
+	}
+	apbt_virt_address = ioremap_nocache(apbt_address, APBT_MMAP_SIZE);
+	if (apbt_virt_address) {
+		pr_debug("Mapped APBT physical addr %p at virtual addr %p\n",\
+			 (void *)apbt_address, (void *)apbt_virt_address);
+	} else {
+		pr_debug("Failed mapping APBT phy address at %p\n",\
+			 (void *)apbt_address);
+		goto panic_noapbt;
+	}
+	apbt_freq = mtmr->freq_hz / USEC_PER_SEC;
+	sfi_free_mtmr(mtmr);
+
+	/* Now figure out the physical timer id for clocksource device */
+	mtmr = sfi_get_mtmr(APBT_CLOCKSOURCE_NUM);
+	if (mtmr == NULL)
+		goto panic_noapbt;
+
+	/* Now figure out the physical timer id */
+	phy_cs_timer_id = (unsigned int)(mtmr->phys_addr & 0xff)
+		/ APBTMRS_REG_SIZE;
+	pr_debug("Use timer %d for clocksource\n", phy_cs_timer_id);
+	return;
+
+panic_noapbt:
+	panic("Failed to setup APB system timer\n");
+
+}
+
+static inline void apbt_clear_mapping(void)
+{
+	iounmap(apbt_virt_address);
+	apbt_virt_address = NULL;
+}
+
+/*
+ * APBT timer interrupt enable / disable
+ */
+static inline int is_apbt_capable(void)
+{
+	return apbt_virt_address ? 1 : 0;
+}
+
+static struct clocksource clocksource_apbt = {
+	.name		= "apbt",
+	.rating		= APBT_CLOCKSOURCE_RATING,
+	.read		= apbt_read_clocksource,
+	.mask		= APBT_MASK,
+	.shift		= APBT_SHIFT,
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.resume		= apbt_restart_clocksource,
+};
+
+/* boot APB clock event device */
+static struct clock_event_device apbt_clockevent = {
+	.name		= "apbt0",
+	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.set_mode	= apbt_set_mode,
+	.set_next_event = apbt_next_event,
+	.shift		= APBT_SHIFT,
+	.irq		= 0,
+	.rating		= APBT_CLOCKEVENT_RATING,
+};
+
+/*
+ * if user does not want to use per CPU apb timer, just give it a lower rating
+ * than local apic timer and skip the late per cpu timer init.
+ */
+static inline int __init setup_x86_mrst_timer(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+
+	if (strcmp("apbt_only", arg) == 0)
+		disable_apbt_percpu = 0;
+	else if (strcmp("lapic_and_apbt", arg) == 0)
+		disable_apbt_percpu = 1;
+	else {
+		pr_warning("X86 MRST timer option %s not recognised"
+			   " use x86_mrst_timer=apbt_only or lapic_and_apbt\n",
+			   arg);
+		return -EINVAL;
+	}
+	return 0;
+}
+__setup("x86_mrst_timer=", setup_x86_mrst_timer);
+
+/*
+ * start count down from 0xffff_ffff. this is done by toggling the enable bit
+ * then load initial load count to ~0.
+ */
+static void apbt_start_counter(int n)
+{
+	unsigned long ctrl = apbt_readl(n, APBTMR_N_CONTROL);
+
+	ctrl &= ~APBTMR_CONTROL_ENABLE;
+	apbt_writel(n, ctrl, APBTMR_N_CONTROL);
+	apbt_writel(n, ~0, APBTMR_N_LOAD_COUNT);
+	/* enable, mask interrupt */
+	ctrl &= ~APBTMR_CONTROL_MODE_PERIODIC;
+	ctrl |= (APBTMR_CONTROL_ENABLE | APBTMR_CONTROL_INT);
+	apbt_writel(n, ctrl, APBTMR_N_CONTROL);
+	/* read it once to get cached counter value initialized */
+	apbt_read_clocksource(&clocksource_apbt);
+}
+
+static irqreturn_t apbt_interrupt_handler(int irq, void *data)
+{
+	struct apbt_dev *dev = (struct apbt_dev *)data;
+	struct clock_event_device *aevt = &dev->evt;
+
+	if (!aevt->event_handler) {
+		printk(KERN_INFO "Spurious APBT timer interrupt on %d\n",
+		       dev->num);
+		return IRQ_NONE;
+	}
+	aevt->event_handler(aevt);
+	return IRQ_HANDLED;
+}
+
+static void apbt_restart_clocksource(struct clocksource *cs)
+{
+	apbt_start_counter(phy_cs_timer_id);
+}
+
+/* Setup IRQ routing via IOAPIC */
+#ifdef CONFIG_SMP
+static void apbt_setup_irq(struct apbt_dev *adev)
+{
+	struct irq_chip *chip;
+	struct irq_desc *desc;
+
+	/* timer0 irq has been setup early */
+	if (adev->irq == 0)
+		return;
+	desc = irq_to_desc(adev->irq);
+	chip = get_irq_chip(adev->irq);
+	disable_irq(adev->irq);
+	desc->status |= IRQ_MOVE_PCNTXT;
+	irq_set_affinity(adev->irq, cpumask_of(adev->cpu));
+	/* APB timer irqs are set up as mp_irqs, timer is edge triggerred */
+	set_irq_chip_and_handler_name(adev->irq, chip, handle_edge_irq, "edge");
+	enable_irq(adev->irq);
+	if (system_state == SYSTEM_BOOTING)
+		if (request_irq(adev->irq, apbt_interrupt_handler,
+				IRQF_TIMER | IRQF_DISABLED | IRQF_NOBALANCING,
+				adev->name, adev)) {
+			printk(KERN_ERR "Failed request IRQ for APBT%d\n",
+			       adev->num);
+		}
+}
+#endif
+
+static void apbt_enable_int(int n)
+{
+	unsigned long ctrl = apbt_readl(n, APBTMR_N_CONTROL);
+	/* clear pending intr */
+	apbt_readl(n, APBTMR_N_EOI);
+	ctrl &= ~APBTMR_CONTROL_INT;