/*
 * 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>
 *
 * Copyright 2001, Travis Geiselbrecht. All rights reserved.
 * Distributed under the terms of the NewOS License.
 */


#include <interrupts.h>

#include <arch/smp.h>
#include <boot/kernel_args.h>
#include <device_manager.h>
#include <kscheduler.h>
#include <interrupt_controller.h>
#include <smp.h>
#include <thread.h>
#include <timer.h>
#include <util/AutoLock.h>
#include <util/DoublyLinkedList.h>
#include <util/kernel_cpp.h>
#include <vm/vm.h>
#include <vm/vm_priv.h>
#include <vm/VMAddressSpace.h>
#include <PCI.h>

#include <string.h>


// defined in arch_exceptions.S
extern int __irqvec_start;
extern int __irqvec_end;

extern"C" void ppc_exception_tail(void);


// the exception contexts for all CPUs
static ppc_cpu_exception_context sCPUExceptionContexts[SMP_MAX_CPUS];


// An iframe stack used in the early boot process when we don't have
// threads yet.
struct iframe_stack gBootFrameStack;

// interrupt controller interface (initialized
// in arch_int_init_post_device_manager())
static struct interrupt_controller_module_info *sPIC;
static void *sPICCookie;


void
arch_int_enable_io_interrupt(int32 irq)
{
        if (!sPIC)
                return;

        // TODO: I have no idea, what IRQ type is appropriate.
        sPIC->enable_io_interrupt(sPICCookie, irq, IRQ_TYPE_LEVEL);
}


void
arch_int_disable_io_interrupt(int32 irq)
{
        if (!sPIC)
                return;

        sPIC->disable_io_interrupt(sPICCookie, irq);
}


/* arch_int_*_interrupts() and friends are in arch_asm.S */


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


extern "C" void ppc_exception_entry(int vector, struct iframe *iframe);
void
ppc_exception_entry(int vector, struct iframe *iframe)
{
        if (vector != 0x900) {
                dprintf("ppc_exception_entry: time %lld vector 0x%x, iframe %p, "
                        "srr0: %p\n", system_time(), vector, iframe, (void*)iframe->srr0);
        }

        Thread *thread = thread_get_current_thread();

        // push iframe
        if (thread)
                ppc_push_iframe(&thread->arch_info.iframes, iframe);
        else
                ppc_push_iframe(&gBootFrameStack, iframe);

        switch (vector) {
                case 0x100: // system reset
                        panic("system reset exception\n");
                        break;
                case 0x200: // machine check
                        panic("machine check exception\n");
                        break;
                case 0x300: // DSI
                case 0x400: // ISI
                {
                        bool kernelDebugger = debug_debugger_running();

                        if (kernelDebugger) {
                                // if this CPU or this thread has a fault handler,
                                // we're allowed to be here
                                cpu_ent* cpu = &gCPU[smp_get_current_cpu()];
                                if (cpu->fault_handler != 0) {
                                        iframe->srr0 = cpu->fault_handler;
                                        iframe->r1 = cpu->fault_handler_stack_pointer;
                                        break;
                                }
                                Thread *thread = thread_get_current_thread();
                                if (thread && thread->fault_handler != 0) {
                                        iframe->srr0 =
                                                reinterpret_cast<uintptr_t>(thread->fault_handler);
                                        break;
                                }

                                // otherwise, not really
                                panic("page fault in debugger without fault handler! Touching "
                                        "address %p from ip %p\n", (void *)iframe->dar,
                                        (void *)iframe->srr0);
                                break;
                        } else if ((iframe->srr1 & MSR_EXCEPTIONS_ENABLED) == 0) {
                                // if the interrupts were disabled, and we are not running the
                                // kernel startup the page fault was not allowed to happen and
                                // we must panic
                                panic("page fault, but interrupts were disabled. Touching "
                                        "address %p from ip %p\n", (void *)iframe->dar,
                                        (void *)iframe->srr0);
                                break;
                        } else if (thread != NULL && thread->page_faults_allowed < 1) {
                                panic("page fault not allowed at this place. Touching address "
                                        "%p from ip %p\n", (void *)iframe->dar,
                                        (void *)iframe->srr0);
                        }

                        enable_interrupts();

                        addr_t newip;

                        vm_page_fault(iframe->dar, iframe->srr0,
                                iframe->dsisr & (1 << 25), // store or load
                                false,
                                iframe->srr1 & (1 << 14), // was the system in user or supervisor
                                &newip);
                        if (newip != 0) {
                                // the page fault handler wants us to modify the iframe to set the
                                // IP the cpu will return to to be this ip
                                iframe->srr0 = newip;
                        }
                        break;
                }

                case 0x500: // external interrupt
                {
                        if (!sPIC) {
                                panic("ppc_exception_entry(): external interrupt although we "
                                        "don't have a PIC driver!");
                                break;
                        }

dprintf("handling I/O interrupts...\n");
                        int irq;
                        while ((irq = sPIC->acknowledge_io_interrupt(sPICCookie)) >= 0) {
// TODO: correctly pass level-triggered vs. edge-triggered to the handler!
                                io_interrupt_handler(irq, true);
                        }
dprintf("handling I/O interrupts done\n");
                        break;
                }

                case 0x600: // alignment exception
                        panic("alignment exception: unimplemented\n");
                        break;
                case 0x700: // program exception
                        panic("program exception: unimplemented\n");
                        break;
                case 0x800: // FP unavailable exception
                        panic("FP unavailable exception: unimplemented\n");
                        break;
                case 0x900: // decrementer exception
                        timer_interrupt();
                        break;
                case 0xc00: // system call
                        panic("system call exception: unimplemented\n");
                        break;
                case 0xd00: // trace exception
                        panic("trace exception: unimplemented\n");
                        break;
                case 0xe00: // FP assist exception
                        panic("FP assist exception: unimplemented\n");
                        break;
                case 0xf00: // performance monitor exception
                        panic("performance monitor exception: unimplemented\n");
                        break;
                case 0xf20: // altivec unavailable exception
                        panic("alitivec unavailable exception: unimplemented\n");
                        break;
                case 0x1000:
                case 0x1100:
                case 0x1200:
                        panic("TLB miss exception: unimplemented\n");
                        break;
                case 0x1300: // instruction address exception
                        panic("instruction address exception: unimplemented\n");
                        break;
                case 0x1400: // system management exception
                        panic("system management exception: unimplemented\n");
                        break;
                case 0x1600: // altivec assist exception
                        panic("altivec assist exception: unimplemented\n");
                        break;
                case 0x1700: // thermal management exception
                        panic("thermal management exception: unimplemented\n");
                        break;
                default:
                        dprintf("unhandled exception type 0x%x\n", vector);
                        print_iframe(iframe);
                        panic("unhandled exception type\n");
        }

        cpu_status state = disable_interrupts();
        if (thread->post_interrupt_callback != NULL) {
                void (*callback)(void*) = thread->post_interrupt_callback;
                void* data = thread->post_interrupt_data;

                thread->post_interrupt_callback = NULL;
                thread->post_interrupt_data = NULL;

                restore_interrupts(state);

                callback(data);
        } else if (thread->cpu->invoke_scheduler) {
                SpinLocker schedulerLocker(thread->scheduler_lock);
                scheduler_reschedule(B_THREAD_READY);
                schedulerLocker.Unlock();
                restore_interrupts(state);
        }

        // pop iframe
        if (thread)
                ppc_pop_iframe(&thread->arch_info.iframes);
        else
                ppc_pop_iframe(&gBootFrameStack);
}


status_t
arch_int_init(kernel_args *args)
{
        return B_OK;
}


status_t
arch_int_init_post_vm(kernel_args *args)
{
        void *handlers = (void *)args->arch_args.exception_handlers.start;

        // We may need to remap the exception handler area into the kernel address
        // space.
        if (!IS_KERNEL_ADDRESS(handlers)) {
                addr_t address = (addr_t)handlers;
                status_t error = ppc_remap_address_range(&address,
                        args->arch_args.exception_handlers.size, true);
                if (error != B_OK) {
                        panic("arch_int_init_post_vm(): Failed to remap the exception "
                                "handler area!");
                        return error;
                }
                handlers = (void*)(address);
        }

        // create a region to map the irq vector code into (physical address 0x0)
        area_id exceptionArea = create_area("exception_handlers",
                &handlers, B_EXACT_ADDRESS, args->arch_args.exception_handlers.size,
                B_ALREADY_WIRED, B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA);
        if (exceptionArea < B_OK)
                panic("arch_int_init2: could not create exception handler region\n");

        dprintf("exception handlers at %p\n", handlers);

        // copy the handlers into this area
        memcpy(handlers, &__irqvec_start, args->arch_args.exception_handlers.size);
        arch_cpu_sync_icache(handlers, args->arch_args.exception_handlers.size);

        // init the CPU exception contexts
        int cpuCount = smp_get_num_cpus();
        for (int i = 0; i < cpuCount; i++) {
                ppc_cpu_exception_context *context = ppc_get_cpu_exception_context(i);
                context->kernel_handle_exception = (void*)&ppc_exception_tail;
                context->exception_context = context;
                // kernel_stack is set when the current thread changes. At this point
                // we don't have threads yet.
        }

        // set the exception context for this CPU
        ppc_set_current_cpu_exception_context(ppc_get_cpu_exception_context(0));

        return B_OK;
}


status_t
arch_int_init_io(kernel_args* args)
{
        return B_OK;
}


template<typename ModuleInfo>
struct Module : DoublyLinkedListLinkImpl<Module<ModuleInfo> > {
        Module(ModuleInfo *module)
                : module(module)
        {
        }

        ~Module()
        {
                if (module)
                        put_module(((module_info*)module)->name);
        }

        ModuleInfo      *module;
};

typedef Module<interrupt_controller_module_info> PICModule;

struct PICModuleList : DoublyLinkedList<PICModule> {
        ~PICModuleList()
        {
                while (PICModule *module = First()) {
                        Remove(module);
                        delete module;
                }
        }
};


class DeviceTreeIterator {
public:
        DeviceTreeIterator(device_manager_info *deviceManager)
                : fDeviceManager(deviceManager),
                  fNode(NULL),
                  fParent(NULL)
        {
                Rewind();
        }

        ~DeviceTreeIterator()
        {
                if (fParent != NULL)
                        fDeviceManager->put_node(fParent);
                if (fNode != NULL)
                        fDeviceManager->put_node(fNode);
        }

        void Rewind()
        {
                fNode = fDeviceManager->get_root_node();
        }

        bool HasNext() const
        {
                return (fNode != NULL);
        }

        device_node *Next()
        {
                if (fNode == NULL)
                        return NULL;

                device_node *foundNode = fNode;

                // get first child
                device_node *child = NULL;
                if (fDeviceManager->get_next_child_node(fNode, NULL, &child)
                                == B_OK) {
                        // move to the child node
                        if (fParent != NULL)
                                fDeviceManager->put_node(fParent);
                        fParent = fNode;
                        fNode = child;

                // no more children; backtrack to find the next sibling
                } else {
                        while (fParent != NULL) {
                                if (fDeviceManager->get_next_child_node(fParent, NULL, &fNode)
                                                == B_OK) {
                                                // get_next_child_node() always puts the node
                                        break;
                                }
                                fNode = fParent;
                                fParent = fDeviceManager->get_parent_node(fNode);
                        }

                        // if we hit the root node again, we're done
                        if (fParent == NULL) {
                                fDeviceManager->put_node(fNode);
                                fNode = NULL;
                        }
                }

                return foundNode;
        }

private:
        device_manager_info *fDeviceManager;
        device_node     *fNode;
        device_node     *fParent;
};


static void
get_interrupt_controller_modules(PICModuleList &list)
{
        const char *namePrefix = "interrupt_controllers/";
        size_t namePrefixLen = strlen(namePrefix);

        char name[B_PATH_NAME_LENGTH];
        size_t length;
        uint32 cookie = 0;
        while (get_next_loaded_module_name(&cookie, name, &(length = sizeof(name)))
                        == B_OK) {
                // an interrupt controller module?
                if (length <= namePrefixLen
                        || strncmp(name, namePrefix, namePrefixLen) != 0) {
                        continue;
                }

                // get the module
                interrupt_controller_module_info *moduleInfo;
                if (get_module(name, (module_info**)&moduleInfo) != B_OK)
                        continue;

                // add it to the list
                PICModule *module = new(nothrow) PICModule(moduleInfo);
                if (!module) {
                        put_module(((module_info*)moduleInfo)->name);
                        continue;
                }
                list.Add(module);
        }
}


static bool
probe_pic_device(device_node *node, PICModuleList &picModules)
{
        for (PICModule *module = picModules.Head();
                 module;
                 module = picModules.GetNext(module)) {
                if (module->module->info.supports_device(node) > 0) {
                        if (module->module->info.register_device(node) == B_OK)
                                return true;
                }
        }

        return false;
}


status_t
arch_int_init_post_device_manager(struct kernel_args *args)
{
        // get the interrupt controller driver modules
        PICModuleList picModules;
        get_interrupt_controller_modules(picModules);
        if (picModules.IsEmpty()) {
                panic("arch_int_init_post_device_manager(): Found no PIC modules!");
                return B_ENTRY_NOT_FOUND;
        }

        // get the device manager module
        device_manager_info *deviceManager;
        status_t error = get_module(B_DEVICE_MANAGER_MODULE_NAME,
                (module_info**)&deviceManager);
        if (error != B_OK) {
                panic("arch_int_init_post_device_manager(): Failed to get device "
                        "manager: %s", strerror(error));
                return error;
        }
        Module<device_manager_info> _deviceManager(deviceManager);      // auto put

        // iterate through the device tree and probe the interrupt controllers
        DeviceTreeIterator iterator(deviceManager);
        while (device_node *node = iterator.Next())
                probe_pic_device(node, picModules);

        // iterate through the tree again and get an interrupt controller node
        iterator.Rewind();
        while (device_node *node = iterator.Next()) {
                uint16 pciBaseClass, pciSubType;
                if (deviceManager->get_attr_uint16(node, B_DEVICE_TYPE,
                                &pciBaseClass, false) == B_OK &&
                        deviceManager->get_attr_uint16(node, B_DEVICE_SUB_TYPE,
                                &pciSubType, false) == B_OK) {
                        bool isPIC = (pciBaseClass == PCI_base_peripheral)
                                && (pciSubType == PCI_pic);

                        if (isPIC) {
                                driver_module_info *driver;
                                void *driverCookie;

                                deviceManager->get_driver(node, (driver_module_info **)&driver, (void **)&driverCookie);

                                sPIC = (interrupt_controller_module_info *)driver;
                                sPICCookie = driverCookie;
                                return B_OK;
                        }
                }
        }

        // no PIC found
        panic("arch_int_init_post_device_manager(): Found no supported PIC!");

        return B_ENTRY_NOT_FOUND;
}


// #pragma mark -

struct ppc_cpu_exception_context *
ppc_get_cpu_exception_context(int cpu)
{
        return sCPUExceptionContexts + cpu;
}


void
ppc_set_current_cpu_exception_context(struct ppc_cpu_exception_context *context)
{
        // translate to physical address
        phys_addr_t physicalPage;
        addr_t inPageOffset = (addr_t)context & (B_PAGE_SIZE - 1);
        status_t error = vm_get_page_mapping(VMAddressSpace::KernelID(),
                (addr_t)context - inPageOffset, &physicalPage);
        if (error != B_OK) {
                panic("ppc_set_current_cpu_exception_context(): Failed to get physical "
                        "address!");
                return;
        }

        asm volatile("mtsprg0 %0" : : "r"(physicalPage + inPageOffset));
}


int32
arch_int_assign_to_cpu(int32 irq, int32 cpu)
{
        // Not yet supported.
        return 0;
}