/*
 * (C) Copyright 2008-2011
 * Graeme Russ, <graeme.russ@gmail.com>
 *
 * (C) Copyright 2002
 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
 *
 * Portions of this file are derived from the Linux kernel source
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <asm/interrupt.h>
#include <asm/io.h>
#include <asm/processor-flags.h>
#include <linux/compiler.h>

#define DECLARE_INTERRUPT(x) \
	".globl irq_"#x"\n" \
	".hidden irq_"#x"\n" \
	".type irq_"#x", @function\n" \
	"irq_"#x":\n" \
	"pushl $"#x"\n" \
	"jmp irq_common_entry\n"

/*
 * Volatile isn't enough to prevent the compiler from reordering the
 * read/write functions for the control registers and messing everything up.
 * A memory clobber would solve the problem, but would prevent reordering of
 * all loads stores around it, which can hurt performance. Solution is to
 * use a variable and mimic reads and writes to it to enforce serialisation
 */
static unsigned long __force_order;

static inline unsigned long read_cr0(void)
{
	unsigned long val;
	asm volatile("mov %%cr0,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

static inline unsigned long read_cr2(void)
{
	unsigned long val;
	asm volatile("mov %%cr2,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

static inline unsigned long read_cr3(void)
{
	unsigned long val;
	asm volatile("mov %%cr3,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

static inline unsigned long read_cr4(void)
{
	unsigned long val;
	asm volatile("mov %%cr4,%0\n\t" : "=r" (val), "=m" (__force_order));
	return val;
}

static inline unsigned long get_debugreg(int regno)
{
	unsigned long val = 0;	/* Damn you, gcc! */

	switch (regno) {
	case 0:
		asm("mov %%db0, %0" : "=r" (val));
		break;
	case 1:
		asm("mov %%db1, %0" : "=r" (val));
		break;
	case 2:
		asm("mov %%db2, %0" : "=r" (val));
		break;
	case 3:
		asm("mov %%db3, %0" : "=r" (val));
		break;
	case 6:
		asm("mov %%db6, %0" : "=r" (val));
		break;
	case 7:
		asm("mov %%db7, %0" : "=r" (val));
		break;
	default:
		val = 0;
	}
	return val;
}

void dump_regs(struct irq_regs *regs)
{
	unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
	unsigned long d0, d1, d2, d3, d6, d7;
	unsigned long sp;

	printf("EIP: %04x:[<%08lx>] EFLAGS: %08lx\n",
			(u16)regs->xcs, regs->eip, regs->eflags);

	printf("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
		regs->eax, regs->ebx, regs->ecx, regs->edx);
	printf("ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n",
		regs->esi, regs->edi, regs->ebp, regs->esp);
	printf(" DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x\n",
	       (u16)regs->xds, (u16)regs->xes, (u16)regs->xfs,
	       (u16)regs->xgs, (u16)regs->xss);

	cr0 = read_cr0();
	cr2 = read_cr2();
	cr3 = read_cr3();
	cr4 = read_cr4();

	printf("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n",
			cr0, cr2, cr3, cr4);

	d0 = get_debugreg(0);
	d1 = get_debugreg(1);
	d2 = get_debugreg(2);
	d3 = get_debugreg(3);

	printf("DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",
			d0, d1, d2, d3);

	d6 = get_debugreg(6);
	d7 = get_debugreg(7);
	printf("DR6: %08lx DR7: %08lx\n",
			d6, d7);

	printf("Stack:\n");
	sp = regs->esp;

	sp += 64;

	while (sp > (regs->esp - 16)) {
		if (sp == regs->esp)
			printf("--->");
		else
			printf("    ");
		printf("0x%8.8lx : 0x%8.8lx\n", sp, (ulong)readl(sp));
		sp -= 4;
	}
}

struct idt_entry {
	u16	base_low;
	u16	selector;
	u8	res;
	u8	access;
	u16	base_high;
} __packed;

struct desc_ptr {
	unsigned short size;
	unsigned long address;
	unsigned short segment;
} __packed;

struct idt_entry idt[256] __attribute__((aligned(16)));

struct desc_ptr idt_ptr;

static inline void load_idt(const struct desc_ptr *dtr)
{
	asm volatile("cs lidt %0" : : "m" (*dtr));
}

void set_vector(u8 intnum, void *routine)
{
	idt[intnum].base_high = (u16)((u32)(routine) >> 16);
	idt[intnum].base_low = (u16)((u32)(routine) & 0xffff);
}

/*
 * Ideally these would be defined static to avoid a checkpatch warning, but
 * the compiler cannot see them in the inline asm and complains that they
 * aren't defined
 */
void irq_0(void);
void irq_1(void);

int cpu_init_interrupts(void)
{
	int i;

	int irq_entry_size = irq_1 - irq_0;
	void *irq_entry = (void *)irq_0;

	/* Just in case... */
	disable_interrupts();

	/* Setup the IDT */
	for (i = 0; i < 256; i++) {
		idt[i].access = 0x8e;
		idt[i].res = 0;
		idt[i].selector = 0x10;
		set_vector(i, irq_entry);
		irq_entry += irq_entry_size;
	}

	idt_ptr.size = 256 * 8;
	idt_ptr.address = (unsigned long) idt;
	idt_ptr.segment = 0x18;

	load_idt(&idt_ptr);

	/* It is now safe to enable interrupts */
	enable_interrupts();

	return 0;
}

void __do_irq(int irq)
{
	printf("Unhandled IRQ : %d\n", irq);
}
void do_irq(int irq) __attribute__((weak, alias("__do_irq")));

void enable_interrupts(void)
{
	asm("sti\n");
}

int disable_interrupts(void)
{
	long flags;

	asm volatile ("pushfl ; popl %0 ; cli\n" : "=g" (flags) : );

	return flags & X86_EFLAGS_IF;
}

/* IRQ Low-Level Service Routine */
void irq_llsr(struct irq_regs *regs)
{
	/*
	 * For detailed description of each exception, refer to:
	 * Intel® 64 and IA-32 Architectures Software Developer's Manual
	 * Volume 1: Basic Architecture
	 * Order Number: 253665-029US, November 2008
	 * Table 6-1. Exceptions and Interrupts
	 */
	switch (regs->irq_id) {
	case 0x00:
		printf("Divide Error (Division by zero)\n");
		dump_regs(regs);
		hang();
		break;
	case 0x01:
		printf("Debug Interrupt (Single step)\n");
		dump_regs(regs);
		break;
	case 0x02:
		printf("NMI Interrupt\n");
		dump_regs(regs);
		break;
	case 0x03:
		printf("Breakpoint\n");
		dump_regs(regs);
		break;
	case 0x04:
		printf("Overflow\n");
		dump_regs(regs);
		hang();
		break;
	case 0x05:
		printf("BOUND Range Exceeded\n");
		dump_regs(regs);
		hang();
		break;
	case 0x06:
		printf("Invalid Opcode (UnDefined Opcode)\n");
		dump_regs(regs);
		hang();
		break;
	case 0x07:
		printf("Device Not Available (No Math Coprocessor)\n");
		dump_regs(regs);
		hang();
		break;
	case 0x08:
		printf("Double fault\n");
		dump_regs(regs);
		hang();
		break;
	case 0x09:
		printf("Co-processor segment overrun\n");
		dump_regs(regs);
		hang();
		break;
	case 0x0a:
		printf("Invalid TSS\n");
		dump_regs(regs);
		break;
	case 0x0b:
		printf("Segment Not Present\n");
		dump_regs(regs);
		hang();
		break;
	case 0x0c:
		printf("Stack Segment Fault\n");
		dump_regs(regs);
		hang();
		break;
	case 0x0d:
		printf("General Protection\n");
		dump_regs(regs);
		break;
	case 0x0e:
		printf("Page fault\n");
		dump_regs(regs);
		hang();
		break;
	case 0x0f:
		printf("Floating-Point Error (Math Fault)\n");
		dump_regs(regs);
		break;
	case 0x10:
		printf("Alignment check\n");
		dump_regs(regs);
		break;
	case 0x11:
		printf("Machine Check\n");
		dump_regs(regs);
		break;
	case 0x12:
		printf("SIMD Floating-Point Exception\n");
		dump_regs(regs);
		break;
	case 0x13:
	case 0x14:
	case 0x15:
	case 0x16:
	case 0x17:
	case 0x18:
	case 0x19:
	case 0x1a:
	case 0x1b:
	case 0x1c:
	case 0x1d:
	case 0x1e:
	case 0x1f:
		printf("Reserved Exception\n");
		dump_regs(regs);
		break;

	default:
		/* Hardware or User IRQ */
		do_irq(regs->irq_id);
	}
}

/*
 * OK - This looks really horrible, but it serves a purpose - It helps create
 * fully relocatable code.
 *  - The call to irq_llsr will be a relative jump
 *  - The IRQ entries will be guaranteed to be in order
 *  Interrupt entries are now very small (a push and a jump) but they are
 *  now slower (all registers pushed on stack which provides complete
 *  crash dumps in the low level handlers
 *
 * Interrupt Entry Point:
 *  - Interrupt has caused eflags, CS and EIP to be pushed
 *  - Interrupt Vector Handler has pushed orig_eax
 *  - pt_regs.esp needs to be adjusted by 40 bytes:
 *      12 bytes pushed by CPU (EFLAGSF, CS, EIP)
 *      4 bytes pushed by vector handler (irq_id)
 *      24 bytes pushed before SP (SS, GS, FS, ES, DS, EAX)
 *      NOTE: Only longs are pushed on/popped off the stack!
 */
asm(".globl irq_common_entry\n" \
	".hidden irq_common_entry\n" \
	".type irq_common_entry, @function\n" \
	"irq_common_entry:\n" \
	"cld\n" \
	"pushl %ss\n" \
	"pushl %gs\n" \
	"pushl %fs\n" \
	"pushl %es\n" \
	"pushl %ds\n" \
	"pushl %eax\n" \
	"movl  %esp, %eax\n" \
	"addl  $40, %eax\n" \
	"pushl %eax\n" \
	"pushl %ebp\n" \
	"pushl %edi\n" \
	"pushl %esi\n" \
	"pushl %edx\n" \
	"pushl %ecx\n" \
	"pushl %ebx\n" \
	"mov   %esp, %eax\n" \
	"call irq_llsr\n" \
	"popl %ebx\n" \
	"popl %ecx\n" \
	"popl %edx\n" \
	"popl %esi\n" \
	"popl %edi\n" \
	"popl %ebp\n" \
	"popl %eax\n" \
	"popl %eax\n" \
	"popl %ds\n" \
	"popl %es\n" \
	"popl %fs\n" \
	"popl %gs\n" \
	"popl %ss\n" \
	"add  $4, %esp\n" \
	"iret\n" \
	DECLARE_INTERRUPT(0) \
	DECLARE_INTERRUPT(1) \
	DECLARE_INTERRUPT(2) \
	DECLARE_INTERRUPT(3) \
	DECLARE_INTERRUPT(4) \
	DECLARE_INTERRUPT(5) \
	DECLARE_INTERRUPT(6) \
	DECLARE_INTERRUPT(7) \
	DECLARE_INTERRUPT(8) \
	DECLARE_INTERRUPT(9) \
	DECLARE_INTERRUPT(10) \
	DECLARE_INTERRUPT(11) \
	DECLARE_INTERRUPT(12) \
	DECLARE_INTERRUPT(13) \
	DECLARE_INTERRUPT(14) \
	DECLARE_INTERRUPT(15) \
	DECLARE_INTERRUPT(16) \
	DECLARE_INTERRUPT(17) \
	DECLARE_INTERRUPT(18) \
	DECLARE_INTERRUPT(19) \
	DECLARE_INTERRUPT(20) \
	DECLARE_INTERRUPT(21) \
	DECLARE_INTERRUPT(22) \
	DECLARE_INTERRUPT(23) \
	DECLARE_INTERRUPT(24) \
	DECLARE_INTERRUPT(25) \
	DECLARE_INTERRUPT(26) \
	DECLARE_INTERRUPT(27) \
	DECLARE_INTERRUPT(28) \
	DECLARE_INTERRUPT(29) \
	DECLARE_INTERRUPT(30) \
	DECLARE_INTERRUPT(31) \
	DECLARE_INTERRUPT(32) \
	DECLARE_INTERRUPT(33) \
	DECLARE_INTERRUPT(34) \
	DECLARE_INTERRUPT(35) \
	DECLARE_INTERRUPT(36) \
	DECLARE_INTERRUPT(37) \
	DECLARE_INTERRUPT(38) \
	DECLARE_INTERRUPT(39) \
	DECLARE_INTERRUPT(40) \
	DECLARE_INTERRUPT(41) \
	DECLARE_INTERRUPT(42) \
	DECLARE_INTERRUPT(43) \
	DECLARE_INTERRUPT(44) \
	DECLARE_INTERRUPT(45) \
	DECLARE_INTERRUPT(46) \
	DECLARE_INTERRUPT(47) \
	DECLARE_INTERRUPT(48) \
	DECLARE_INTERRUPT(49) \
	DECLARE_INTERRUPT(50) \
	DECLARE_INTERRUPT(51) \
	DECLARE_INTERRUPT(52) \
	DECLARE_INTERRUPT(53) \
	DECLARE_INTERRUPT(54) \
	DECLARE_INTERRUPT(55) \
	DECLARE_INTERRUPT(56) \
	DECLARE_INTERRUPT(57) \
	DECLARE_INTERRUPT(58) \
	DECLARE_INTERRUPT(59) \
	DECLARE_INTERRUPT(60) \
	DECLARE_INTERRUPT(61) \
	DECLARE_INTERRUPT(62) \
	DECLARE_INTERRUPT(63) \
	DECLARE_INTERRUPT(64) \
	DECLARE_INTERRUPT(65) \
	DECLARE_INTERRUPT(66) \
	DECLARE_INTERRUPT(67) \
	DECLARE_INTERRUPT(68) \
	DECLARE_INTERRUPT(69) \
	DECLARE_INTERRUPT(70) \
	DECLARE_INTERRUPT(71) \
	DECLARE_INTERRUPT(72) \
	DECLARE_INTERRUPT(73) \
	DECLARE_INTERRUPT(74) \
	DECLARE_INTERRUPT(75) \
	DECLARE_INTERRUPT(76) \
	DECLARE_INTERRUPT(77) \
	DECLARE_INTERRUPT(78) \
	DECLARE_INTERRUPT(79) \
	DECLARE_INTERRUPT(80) \
	DECLARE_INTERRUPT(81) \
	DECLARE_INTERRUPT(82) \
	DECLARE_INTERRUPT(83) \
	DECLARE_INTERRUPT(84) \
	DECLARE_INTERRUPT(85) \
	DECLARE_INTERRUPT(86) \
	DECLARE_INTERRUPT(87) \
	DECLARE_INTERRUPT(88) \
	DECLARE_INTERRUPT(89) \
	DECLARE_INTERRUPT(90) \
	DECLARE_INTERRUPT(91) \
	DECLARE_INTERRUPT(92) \
	DECLARE_INTERRUPT(93) \
	DECLARE_INTERRUPT(94) \
	DECLARE_INTERRUPT(95) \
	DECLARE_INTERRUPT(97) \
	DECLARE_INTERRUPT(96) \
	DECLARE_INTERRUPT(98) \
	DECLARE_INTERRUPT(99) \
	DECLARE_INTERRUPT(100) \
	DECLARE_INTERRUPT(101) \
	DECLARE_INTERRUPT(102) \
	DECLARE_INTERRUPT(103) \
	DECLARE_INTERRUPT(104) \
	DECLARE_INTERRUPT(105) \
	DECLARE_INTERRUPT(106) \
	DECLARE_INTERRUPT(107) \
	DECLARE_INTERRUPT(108) \
	DECLARE_INTERRUPT(109) \
	DECLARE_INTERRUPT(110) \
	DECLARE_INTERRUPT(111) \
	DECLARE_INTERRUPT(112) \
	DECLARE_INTERRUPT(113) \
	DECLARE_INTERRUPT(114) \
	DECLARE_INTERRUPT(115) \
	DECLARE_INTERRUPT(116) \
	DECLARE_INTERRUPT(117) \
	DECLARE_INTERRUPT(118) \
	DECLARE_INTERRUPT(119) \
	DECLARE_INTERRUPT(120) \
	DECLARE_INTERRUPT(121) \
	DECLARE_INTERRUPT(122) \
	DECLARE_INTERRUPT(123) \
	DECLARE_INTERRUPT(124) \
	DECLARE_INTERRUPT(125) \
	DECLARE_INTERRUPT(126) \
	DECLARE_INTERRUPT(127) \
	DECLARE_INTERRUPT(128) \
	DECLARE_INTERRUPT(129) \
	DECLARE_INTERRUPT(130) \
	DECLARE_INTERRUPT(131) \
	DECLARE_INTERRUPT(132) \
	DECLARE_INTERRUPT(133) \
	DECLARE_INTERRUPT(134) \
	DECLARE_INTERRUPT(135) \
	DECLARE_INTERRUPT(136) \
	DECLARE_INTERRUPT(137) \
	DECLARE_INTERRUPT(138) \
	DECLARE_INTERRUPT(139) \
	DECLARE_INTERRUPT(140) \
	DECLARE_INTERRUPT(141) \
	DECLARE_INTERRUPT(142) \
	DECLARE_INTERRUPT(143) \
	DECLARE_INTERRUPT(144) \
	DECLARE_INTERRUPT(145) \
	DECLARE_INTERRUPT(146) \
	DECLARE_INTERRUPT(147) \
	DECLARE_INTERRUPT(148) \
	DECLARE_INTERRUPT(149) \
	DECLARE_INTERRUPT(150) \
	DECLARE_INTERRUPT(151) \
	DECLARE_INTERRUPT(152) \
	DECLARE_INTERRUPT(153) \
	DECLARE_INTERRUPT(154) \
	DECLARE_INTERRUPT(155) \
	DECLARE_INTERRUPT(156) \
	DECLARE_INTERRUPT(157) \
	DECLARE_INTERRUPT(158) \
	DECLARE_INTERRUPT(159) \
	DECLARE_INTERRUPT(160) \
	DECLARE_INTERRUPT(161) \
	DECLARE_INTERRUPT(162) \
	DECLARE_INTERRUPT(163) \
	DECLARE_INTERRUPT(164) \
	DECLARE_INTERRUPT(165) \
	DECLARE_INTERRUPT(166) \
	DECLARE_INTERRUPT(167) \
	DECLARE_INTERRUPT(168) \
	DECLARE_INTERRUPT(169) \
	DECLARE_INTERRUPT(170) \
	DECLARE_INTERRUPT(171) \
	DECLARE_INTERRUPT(172) \
	DECLARE_INTERRUPT(173) \
	DECLARE_INTERRUPT(174) \
	DECLARE_INTERRUPT(175) \
	DECLARE_INTERRUPT(176) \
	DECLARE_INTERRUPT(177) \
	DECLARE_INTERRUPT(178) \
	DECLARE_INTERRUPT(179) \
	DECLARE_INTERRUPT(180) \
	DECLARE_INTERRUPT(181) \
	DECLARE_INTERRUPT(182) \
	DECLARE_INTERRUPT(183) \
	DECLARE_INTERRUPT(184) \
	DECLARE_INTERRUPT(185) \
	DECLARE_INTERRUPT(186) \
	DECLARE_INTERRUPT(187) \
	DECLARE_INTERRUPT(188) \
	DECLARE_INTERRUPT(189) \
	DECLARE_INTERRUPT(190) \
	DECLARE_INTERRUPT(191) \
	DECLARE_INTERRUPT(192) \
	DECLARE_INTERRUPT(193) \
	DECLARE_INTERRUPT(194) \
	DECLARE_INTERRUPT(195) \
	DECLARE_INTERRUPT(196) \
	DECLARE_INTERRUPT(197) \
	DECLARE_INTERRUPT(198) \
	DECLARE_INTERRUPT(199) \
	DECLARE_INTERRUPT(200) \
	DECLARE_INTERRUPT(201) \
	DECLARE_INTERRUPT(202) \
	DECLARE_INTERRUPT(203) \
	DECLARE_INTERRUPT(204) \
	DECLARE_INTERRUPT(205) \
	DECLARE_INTERRUPT(206) \
	DECLARE_INTERRUPT(207) \
	DECLARE_INTERRUPT(208) \
	DECLARE_INTERRUPT(209) \
	DECLARE_INTERRUPT(210) \
	DECLARE_INTERRUPT(211) \
	DECLARE_INTERRUPT(212) \
	DECLARE_INTERRUPT(213) \
	DECLARE_INTERRUPT(214) \
	DECLARE_INTERRUPT(215) \
	DECLARE_INTERRUPT(216) \
	DECLARE_INTERRUPT(217) \
	DECLARE_INTERRUPT(218) \
	DECLARE_INTERRUPT(219) \
	DECLARE_INTERRUPT(220) \
	DECLARE_INTERRUPT(221) \
	DECLARE_INTERRUPT(222) \
	DECLARE_INTERRUPT(223) \
	DECLARE_INTERRUPT(224) \
	DECLARE_INTERRUPT(225) \
	DECLARE_INTERRUPT(226) \
	DECLARE_INTERRUPT(227) \
	DECLARE_INTERRUPT(228) \
	DECLARE_INTERRUPT(229) \
	DECLARE_INTERRUPT(230) \
	DECLARE_INTERRUPT(231) \
	DECLARE_INTERRUPT(232) \
	DECLARE_INTERRUPT(233) \
	DECLARE_INTERRUPT(234) \
	DECLARE_INTERRUPT(235) \
	DECLARE_INTERRUPT(236) \
	DECLARE_INTERRUPT(237) \
	DECLARE_INTERRUPT(238) \
	DECLARE_INTERRUPT(239) \
	DECLARE_INTERRUPT(240) \
	DECLARE_INTERRUPT(241) \
	DECLARE_INTERRUPT(242) \
	DECLARE_INTERRUPT(243) \
	DECLARE_INTERRUPT(244) \
	DECLARE_INTERRUPT(245) \
	DECLARE_INTERRUPT(246) \
	DECLARE_INTERRUPT(247) \
	DECLARE_INTERRUPT(248) \
	DECLARE_INTERRUPT(249) \
	DECLARE_INTERRUPT(250) \
	DECLARE_INTERRUPT(251) \
	DECLARE_INTERRUPT(252) \
	DECLARE_INTERRUPT(253) \
	DECLARE_INTERRUPT(254) \
	DECLARE_INTERRUPT(255));