/*
 * Copyright 2003-2011, Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *              Axel Dörfler <axeld@pinc-software.de>
 *              Ingo Weinhold <bonefish@cs.tu-berlin.de>
 */


#include <arch/debug.h>

#include <arch_cpu.h>
#include <debug.h>
#include <elf.h>
#include <kernel.h>
#include <kimage.h>
#include <thread.h>


struct stack_frame {
        struct stack_frame      *previous;
        addr_t                          return_address;
};

#define NUM_PREVIOUS_LOCATIONS 32

extern struct iframe_stack gBootFrameStack;


static bool
already_visited(uint32 *visited, int32 *_last, int32 *_num, uint32 framePointer)
{
        int32 last = *_last;
        int32 num = *_num;
        int32 i;

        for (i = 0; i < num; i++) {
                if (visited[(NUM_PREVIOUS_LOCATIONS + last - i)
                                % NUM_PREVIOUS_LOCATIONS] == framePointer) {
                        return true;
                }
        }

        *_last = last = (last + 1) % NUM_PREVIOUS_LOCATIONS;
        visited[last] = framePointer;

        if (num < NUM_PREVIOUS_LOCATIONS)
                *_num = num + 1;

        return false;
}


static inline stack_frame *
get_current_stack_frame()
{
        stack_frame *frame;
        asm volatile("mr %0, %%r1" : "=r"(frame));
        return frame;
}


static status_t
get_next_frame(addr_t framePointer, addr_t *next, addr_t *ip)
{
        stack_frame frame;
        if (debug_memcpy(B_CURRENT_TEAM, &frame, (void*)framePointer, sizeof(frame))
                        != B_OK) {
                return B_BAD_ADDRESS;
        }

        *ip = frame.return_address;
        *next = (addr_t)frame.previous;

        return B_OK;
}


static void
print_stack_frame(Thread *thread, addr_t ip, addr_t framePointer,
        addr_t nextFramePointer)
{
        addr_t diff = nextFramePointer - framePointer;

        // kernel space/user space switch
        if (diff & 0x80000000)
                diff = 0;

        // lookup symbol
        const char *symbol, *image;
        addr_t baseAddress;
        bool exactMatch;
        status_t status = elf_debug_lookup_symbol_address(ip, &baseAddress, &symbol,
                &image, &exactMatch);
        if (status != B_OK && !IS_KERNEL_ADDRESS(ip) && thread) {
                // try to locate the image in the images loaded into user space
                status = elf_debug_lookup_user_symbol_address(thread->team, ip,
                        &baseAddress, &symbol, &image, &exactMatch);
        }
        if (status == B_OK) {
                if (symbol != NULL) {
                        kprintf("%08lx (+%4ld) %08lx   <%s>:%s + 0x%04lx%s\n", framePointer,
                                diff, ip, image, symbol, ip - baseAddress,
                                (exactMatch ? "" : " (nearest)"));
                } else {
                        kprintf("%08lx (+%4ld) %08lx   <%s@%p>:unknown + 0x%04lx\n",
                                framePointer, diff, ip, image, (void *)baseAddress,
                                ip - baseAddress);
                }
        } else
                kprintf("%08lx (+%4ld) %08lx\n", framePointer, diff, ip);
}


static int
stack_trace(int argc, char **argv)
{
        uint32 previousLocations[NUM_PREVIOUS_LOCATIONS];
        struct iframe_stack *frameStack;
        Thread *thread;
        addr_t framePointer;
        int32 i, num = 0, last = 0;

        if (argc < 2) {
                thread = thread_get_current_thread();
                int32 cpu = smp_get_current_cpu();
                framePointer = debug_get_debug_registers(cpu)->r1;
        } else {
// TODO: Add support for stack traces of other threads.
/*              thread_id id = strtoul(argv[1], NULL, 0);
                thread = Thread::GetDebug(id);
                if (thread == NULL) {
                        kprintf("could not find thread %ld\n", id);
                        return 0;
                }

                // read %ebp from the thread's stack stored by a pushad
                ebp = thread->arch_info.current_stack.esp[2];

                if (id != thread_get_current_thread_id()) {
                        // switch to the page directory of the new thread to be
                        // able to follow the stack trace into userland
                        addr_t newPageDirectory = (addr_t)x86_next_page_directory(
                                thread_get_current_thread(), thread);

                        if (newPageDirectory != 0) {
                                read_cr3(oldPageDirectory);
                                write_cr3(newPageDirectory);
                        }
                }
*/
kprintf("Stack traces of other threads not supported yet!\n");
return 0;
        }

        // We don't have a thread pointer early in the boot process
        if (thread != NULL)
                frameStack = &thread->arch_info.iframes;
        else
                frameStack = &gBootFrameStack;

        for (i = 0; i < frameStack->index; i++) {
                kprintf("iframe %p (end = %p)\n",
                        frameStack->frames[i], frameStack->frames[i] + 1);
        }

        if (thread != NULL) {
                kprintf("stack trace for thread 0x%lx \"%s\"\n", thread->id,
                        thread->name);

                kprintf("    kernel stack: %p to %p\n",
                        (void *)thread->kernel_stack_base,
                        (void *)(thread->kernel_stack_top));
                if (thread->user_stack_base != 0) {
                        kprintf("      user stack: %p to %p\n",
                                (void *)thread->user_stack_base,
                                (void *)(thread->user_stack_base + thread->user_stack_size));
                }
        }

        kprintf("frame            caller     <image>:function + offset\n");

        for (;;) {
                // see if the frame pointer matches the iframe
                struct iframe *frame = NULL;
                for (i = 0; i < frameStack->index; i++) {
                        if (framePointer == (((addr_t)frameStack->frames[i] - 8) & ~0xf)) {
                                // it's an iframe
                                frame = frameStack->frames[i];
                                break;
                        }
                }

                if (frame) {
                        kprintf("iframe at %p\n", frame);
                        kprintf("   r0 0x%08lx    r1 0x%08lx    r2 0x%08lx    r3 0x%08lx\n",
                                frame->r0, frame->r1, frame->r2, frame->r3);
                        kprintf("   r4 0x%08lx    r5 0x%08lx    r6 0x%08lx    r7 0x%08lx\n",
                                frame->r4, frame->r5, frame->r6, frame->r7);
                        kprintf("   r8 0x%08lx    r9 0x%08lx   r10 0x%08lx   r11 0x%08lx\n",
                                frame->r8, frame->r9, frame->r10, frame->r11);
                        kprintf("  r12 0x%08lx   r13 0x%08lx   r14 0x%08lx   r15 0x%08lx\n",
                                frame->r12, frame->r13, frame->r14, frame->r15);
                        kprintf("  r16 0x%08lx   r17 0x%08lx   r18 0x%08lx   r19 0x%08lx\n",
                                frame->r16, frame->r17, frame->r18, frame->r19);
                        kprintf("  r20 0x%08lx   r21 0x%08lx   r22 0x%08lx   r23 0x%08lx\n",
                                frame->r20, frame->r21, frame->r22, frame->r23);
                        kprintf("  r24 0x%08lx   r25 0x%08lx   r26 0x%08lx   r27 0x%08lx\n",
                                frame->r24, frame->r25, frame->r26, frame->r27);
                        kprintf("  r28 0x%08lx   r29 0x%08lx   r30 0x%08lx   r31 0x%08lx\n",
                                frame->r28, frame->r29, frame->r30, frame->r31);
                        kprintf("   lr 0x%08lx    cr 0x%08lx   xer 0x%08lx   ctr 0x%08lx\n",
                                frame->lr, frame->cr, frame->xer, frame->ctr);
                        kprintf("fpscr 0x%08lx\n", frame->fpscr);
                        kprintf(" srr0 0x%08lx  srr1 0x%08lx   dar 0x%08lx dsisr 0x%08lx\n",
                                frame->srr0, frame->srr1, frame->dar, frame->dsisr);
                        kprintf(" vector: 0x%lx\n", frame->vector);

                        print_stack_frame(thread, frame->srr0, framePointer, frame->r1);
                        framePointer = frame->r1;
                } else {
                        addr_t ip, nextFramePointer;

                        if (get_next_frame(framePointer, &nextFramePointer, &ip) != B_OK) {
                                kprintf("%08lx -- read fault\n", framePointer);
                                break;
                        }

                        if (ip == 0 || framePointer == 0)
                                break;

                        print_stack_frame(thread, ip, framePointer, nextFramePointer);
                        framePointer = nextFramePointer;
                }

                if (already_visited(previousLocations, &last, &num, framePointer)) {
                        kprintf("circular stack frame: %p!\n", (void *)framePointer);
                        break;
                }
                if (framePointer == 0)
                        break;
        }

/*      if (oldPageDirectory != 0) {
                // switch back to the previous page directory to no cause any troubles
                write_cr3(oldPageDirectory);
        }
*/

        return 0;
}



// #pragma mark -


void
arch_debug_save_registers(struct arch_debug_registers* registers)
{
        // get the caller's frame pointer
        stack_frame* frame = (stack_frame*)get_current_stack_frame();
        registers->r1 = (addr_t)frame->previous;
}


void
arch_debug_stack_trace(void)
{
        stack_trace(0, NULL);
}


bool
arch_debug_contains_call(Thread *thread, const char *symbol,
        addr_t start, addr_t end)
{
        return false;
}


int32
arch_debug_get_stack_trace(addr_t* returnAddresses, int32 maxCount,
        int32 skipIframes, int32 skipFrames, uint32 flags)
{
        // TODO: Implement!
        return 0;
}


void*
arch_debug_get_interrupt_pc(bool* _isSyscall)
{
        // TODO: Implement!
        return NULL;
}


void
arch_debug_unset_current_thread(void)
{
        // TODO: Implement!
}


bool
arch_is_debug_variable_defined(const char* variableName)
{
        // TODO: Implement!
        return false;
}


status_t
arch_set_debug_variable(const char* variableName, uint64 value)
{
        // TODO: Implement!
        return B_ENTRY_NOT_FOUND;
}


status_t
arch_get_debug_variable(const char* variableName, uint64* value)
{
        // TODO: Implement!
        return B_ENTRY_NOT_FOUND;
}


ssize_t
arch_debug_gdb_get_registers(char* buffer, size_t bufferSize)
{
        // TODO: Implement!
        return B_NOT_SUPPORTED;
}


void
arch_debug_snooze(bigtime_t duration)
{
        spin(duration);
}


status_t
arch_debug_init(kernel_args *args)
{
        add_debugger_command("where", &stack_trace, "Same as \"sc\"");
        add_debugger_command("bt", &stack_trace, "Same as \"sc\" (as in gdb)");
        add_debugger_command("sc", &stack_trace, "Stack crawl for current thread");

        return B_NO_ERROR;
}