/*
 *
 * Copyright (c) 2009, Microsoft Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 * Authors:
 *   Haiyang Zhang <haiyangz@microsoft.com>
 *   Hank Janssen  <hjanssen@microsoft.com>
 *
 */


#include "include/logging.h"
#include "VmbusPrivate.h"

//
// Globals
//

// The one and only
HV_CONTEXT gHvContext={
	.SynICInitialized = FALSE,
	.HypercallPage = NULL,
	.SignalEventParam = NULL,
	.SignalEventBuffer = NULL,
};


/*++

Name:
	HvQueryHypervisorPresence()

Description:
	Query the cpuid for presense of windows hypervisor

--*/
static int
HvQueryHypervisorPresence (
    void
    )
{
    unsigned int eax;
    unsigned int ebx;
    unsigned int ecx;
    unsigned int edx;
    unsigned int op;

    eax = 0;
    ebx = 0;
    ecx = 0;
    edx = 0;
    op = HvCpuIdFunctionVersionAndFeatures;
    do_cpuid(op, &eax, &ebx, &ecx, &edx);

	return (ecx & HV_PRESENT_BIT);
}


/*++

Name:
	HvQueryHypervisorInfo()

Description:
	Get version info of the windows hypervisor

--*/
static int
HvQueryHypervisorInfo (
    void
    )
{
    unsigned int eax;
    unsigned int ebx;
    unsigned int ecx;
    unsigned int edx;
    unsigned int maxLeaf;
    unsigned int op;

    //
    // Its assumed that this is called after confirming that Viridian is present.
    // Query id and revision.
    //

    eax = 0;
    ebx = 0;
    ecx = 0;
    edx = 0;
    op = HvCpuIdFunctionHvVendorAndMaxFunction;
    do_cpuid(op, &eax, &ebx, &ecx, &edx);

    DPRINT_INFO(VMBUS, "Vendor ID: %c%c%c%c%c%c%c%c%c%c%c%c",
           (ebx & 0xFF),
           ((ebx >> 8) & 0xFF),
           ((ebx >> 16) & 0xFF),
           ((ebx >> 24) & 0xFF),
           (ecx & 0xFF),
           ((ecx >> 8) & 0xFF),
           ((ecx >> 16) & 0xFF),
           ((ecx >> 24) & 0xFF),
           (edx & 0xFF),
           ((edx >> 8) & 0xFF),
           ((edx >> 16) & 0xFF),
           ((edx >> 24) & 0xFF));

    maxLeaf = eax;
    eax = 0;
    ebx = 0;
    ecx = 0;
    edx = 0;
    op = HvCpuIdFunctionHvInterface;
    do_cpuid(op, &eax, &ebx, &ecx, &edx);

    DPRINT_INFO(VMBUS, "Interface ID: %c%c%c%c",
           (eax & 0xFF),
           ((eax >> 8) & 0xFF),
           ((eax >> 16) & 0xFF),
           ((eax >> 24) & 0xFF));

	 if (maxLeaf >= HvCpuIdFunctionMsHvVersion) {
        eax = 0;
        ebx = 0;
        ecx = 0;
        edx = 0;
        op = HvCpuIdFunctionMsHvVersion;
        do_cpuid(op, &eax, &ebx, &ecx, &edx);
        DPRINT_INFO(VMBUS, "OS Build:%d-%d.%d-%d-%d.%d",
               eax,
               ebx >> 16,
               ebx & 0xFFFF,
               ecx,
               edx >> 24,
               edx & 0xFFFFFF);
    }
    return maxLeaf;
}


/*++

Name:
	HvDoHypercall()

Description:
	Invoke the specified hypercall

--*/
static UINT64
HvDoHypercall (
    UINT64  Control,
    void*   Input,
    void*   Output
    )
{
#ifdef CONFIG_X86_64
    UINT64 hvStatus=0;
    UINT64 inputAddress = (Input)? GetPhysicalAddress(Input) : 0;
	UINT64 outputAddress = (Output)? GetPhysicalAddress(Output) : 0;
    volatile void* hypercallPage = gHvContext.HypercallPage;

    DPRINT_DBG(VMBUS, "Hypercall <control %llx input phys %llx virt %p output phys %llx virt %p hypercall %p>",
		Control,
		inputAddress,
		Input,
		outputAddress,
		Output,
		hypercallPage);

	__asm__ __volatile__ ("mov %0, %%r8" : : "r" (outputAddress):  "r8");
	__asm__ __volatile__ ("call *%3" : "=a"(hvStatus): "c" (Control), "d" (inputAddress), "m" (hypercallPage));

    DPRINT_DBG(VMBUS, "Hypercall <return %llx>",  hvStatus);

    return hvStatus;

#else

    UINT32 controlHi = Control >> 32;
    UINT32 controlLo = Control & 0xFFFFFFFF;
    UINT32 hvStatusHi = 1;
    UINT32 hvStatusLo = 1;
    UINT64 inputAddress = (Input) ? GetPhysicalAddress(Input) : 0;
    UINT32 inputAddressHi = inputAddress >> 32;
    UINT32 inputAddressLo = inputAddress & 0xFFFFFFFF;
	UINT64 outputAddress = (Output) ?GetPhysicalAddress(Output) : 0;
    UINT32 outputAddressHi = outputAddress >> 32;
    UINT32 outputAddressLo = outputAddress & 0xFFFFFFFF;
    volatile void* hypercallPage = gHvContext.HypercallPage;

    DPRINT_DBG(VMBUS, "Hypercall <control %llx input %p output %p>",
		Control,
		Input,
		Output);

	__asm__ __volatile__ ("call *%8" : "=d"(hvStatusHi), "=a"(hvStatusLo) : "d" (controlHi), "a" (controlLo), "b" (inputAddressHi), "c" (inputAddressLo), "D"(outputAddressHi), "S"(outputAddressLo), "m" (hypercallPage));


    DPRINT_DBG(VMBUS, "Hypercall <return %llx>",  hvStatusLo | ((UINT64)hvStatusHi << 32));

    return (hvStatusLo | ((UINT64)hvStatusHi << 32));
#endif // x86_64
}

/*++

Name:
	HvInit()

Description:
	Main initialization routine. This routine must be called
	before any other routines in here are called

--*/
static int
HvInit (
    void
    )
{
	int ret=0;
    int maxLeaf;
	HV_X64_MSR_HYPERCALL_CONTENTS hypercallMsr;
	void* virtAddr=0;
	ULONG_PTR physAddr=0;

	DPRINT_ENTER(VMBUS);

	memset(gHvContext.synICEventPage, 0, sizeof(HANDLE)*MAX_NUM_CPUS);
	memset(gHvContext.synICMessagePage, 0, sizeof(HANDLE)*MAX_NUM_CPUS);

	if (!HvQueryHypervisorPresence())
	{
		DPRINT_ERR(VMBUS, "No Windows hypervisor detected!!");
		goto Cleanup;
	}

	DPRINT_INFO(VMBUS, "Windows hypervisor detected! Retrieving more info...");

    maxLeaf = HvQueryHypervisorInfo();
    //HvQueryHypervisorFeatures(maxLeaf);

	// Determine if we are running on xenlinux (ie x2v shim) or native linux
	gHvContext.GuestId = ReadMsr(HV_X64_MSR_GUEST_OS_ID);

	if (gHvContext.GuestId == 0)
	{
		// Write our OS info
		WriteMsr(HV_X64_MSR_GUEST_OS_ID, HV_LINUX_GUEST_ID);

		gHvContext.GuestId = HV_LINUX_GUEST_ID;
	}

	// See if the hypercall page is already set
	hypercallMsr.AsUINT64 = ReadMsr(HV_X64_MSR_HYPERCALL);

	if (gHvContext.GuestId == HV_LINUX_GUEST_ID)
	{
		// Allocate the hypercall page memory
		//virtAddr = PageAlloc(1);
		virtAddr = VirtualAllocExec(PAGE_SIZE);

		if (!virtAddr)
		{
			DPRINT_ERR(VMBUS, "unable to allocate hypercall page!!");
			goto Cleanup;
		}

		hypercallMsr.Enable = 1;
		//hypercallMsr.GuestPhysicalAddress = Logical2PhysicalAddr(virtAddr) >> PAGE_SHIFT;
		hypercallMsr.GuestPhysicalAddress = Virtual2Physical(virtAddr) >> PAGE_SHIFT;
		WriteMsr(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);

        // Confirm that hypercall page did get setup.
		hypercallMsr.AsUINT64 = 0;
		hypercallMsr.AsUINT64 = ReadMsr(HV_X64_MSR_HYPERCALL);

		if (!hypercallMsr.Enable)
		{
			DPRINT_ERR(VMBUS, "unable to set hypercall page!!");
			goto Cleanup;
		}

		gHvContext.HypercallPage = virtAddr;
	}
	else
	{
		DPRINT_ERR(VMBUS, "Unknown guest id (0x%llx)!!", gHvContext.GuestId);
		goto Cleanup;
	}

    DPRINT_INFO(VMBUS, "Hypercall page VA=0x%08x, PA=0x%08x",
               (unsigned long)gHvContext.HypercallPage,
               (unsigned long)hypercallMsr.GuestPhysicalAddress << PAGE_SHIFT);

	// Setup the global signal event param for the signal event hypercall
	gHvContext.SignalEventBuffer = MemAlloc(sizeof(HV_INPUT_SIGNAL_EVENT_BUFFER));
	if (!gHvContext.SignalEventBuffer)
	{
		goto Cleanup;
	}

	gHvContext.SignalEventParam = (PHV_INPUT_SIGNAL_EVENT)(ALIGN_UP((ULONG_PTR)gHvContext.SignalEventBuffer, HV_HYPERCALL_PARAM_ALIGN));
	gHvContext.SignalEventParam->ConnectionId.AsUINT32 = 0;
	gHvContext.SignalEventParam->ConnectionId.u.Id = VMBUS_EVENT_CONNECTION_ID;
	gHvContext.SignalEventParam->FlagNumber = 0;
	gHvContext.SignalEventParam->RsvdZ = 0;

    //DPRINT_DBG(VMBUS, "My id %llu", HvGetCurrentPartitionId());

	DPRINT_EXIT(VMBUS);

    return ret;

Cleanup:
	if (virtAddr)
	{
		if (hypercallMsr.Enable)
		{
			hypercallMsr.AsUINT64 = 0;
			WriteMsr(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);
		}

		VirtualFree(virtAddr);
	}
	ret = -1;
	DPRINT_EXIT(VMBUS);

	return ret;
}


/*++

Name:
	HvCleanup()

Description:
	Cleanup routine. This routine is called normally during driver unloading or exiting.

--*/
void
HvCleanup (
    void
    )
{
	HV_X64_MSR_HYPERCALL_CONTENTS hypercallMsr;

	DPRINT_ENTER(VMBUS);

	if (gHvContext.SignalEventBuffer)
	{
		MemFree(gHvContext.SignalEventBuffer);
		gHvContext.SignalEventBuffer = NULL;
		gHvContext.SignalEventParam = NULL;
	}

	if (gHvContext.GuestId == HV_LINUX_GUEST_ID)
	{
		if (gHvContext.HypercallPage)
		{
			hypercallMsr.AsUINT64 = 0;
			WriteMsr(HV_X64_MSR_HYPERCALL, hypercallMsr.AsUINT64);
			VirtualFree(gHvContext.HypercallPage);
			gHvContext.HypercallPage = NULL;
		}
	}

	DPRINT_EXIT(VMBUS);

}


/*++

Name:
	HvPostMessage()

Description:
	Post a message using the hypervisor message IPC. This
	involves a hypercall.

--*/
HV_STATUS
HvPostMessage(
	HV_CONNECTION_ID connectionId,
	HV_MESSAGE_TYPE  messageType,
	void *            payload,
	SIZE_T           payloadSize
	)
{
	struct alignedInput {
		UINT64					alignment8;
		HV_INPUT_POST_MESSAGE	msg;
	};

	PHV_INPUT_POST_MESSAGE alignedMsg;
	HV_STATUS status;
	ULONG_PTR addr;

	if (payloadSize > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
	{
		return -1;
	}

	addr = (ULONG_PTR)MemAllocAtomic(sizeof(struct alignedInput));

	if (!addr)
	{
		return -1;
	}

	alignedMsg = (PHV_INPUT_POST_MESSAGE)(ALIGN_UP(addr, HV_HYPERCALL_PARAM_ALIGN));

	alignedMsg->ConnectionId = connectionId;
	alignedMsg->MessageType = messageType;
	alignedMsg->PayloadSize = payloadSize;
	memcpy((void*)alignedMsg->Payload, payload, payloadSize);

	status = HvDoHypercall(HvCallPostMessage, alignedMsg, 0) & 0xFFFF;

	MemFree((void*)addr);

	return status;
}


/*++

Name:
	HvSignalEvent()

Description:
	Signal an event on the specified connection using the hypervisor event IPC. This
	involves a hypercall.

--*/
HV_STATUS
HvSignalEvent(
	)
{
	HV_STATUS status;

	status = HvDoHypercall(HvCallSignalEvent, gHvContext.SignalEventParam, 0) & 0xFFFF;

	return status;
}


/*++

Name:
	HvSynicInit()

Description:
	Initialize the Synthethic Interrupt Controller. If it is already initialized by
	another entity (ie x2v shim), we need to retrieve the initialized message and event pages.
	Otherwise, we create and initialize the message and event pages.

--*/
int
HvSynicInit (
	UINT32 irqVector
	)
{
	UINT64			version;
	HV_SYNIC_SIMP	simp;
	HV_SYNIC_SIEFP	siefp;
    HV_SYNIC_SINT	sharedSint;
	HV_SYNIC_SCONTROL sctrl;
	UINT64			guestID;
	int ret=0;

	DPRINT_ENTER(VMBUS);

	if (!gHvContext.HypercallPage)
	{
		DPRINT_EXIT(VMBUS);
		return ret;
	}

	// Check the version
	version = ReadMsr(HV_X64_MSR_SVERSION);

	DPRINT_INFO(VMBUS, "SynIC version: %llx", version);

	// TODO: Handle SMP
	if (gHvContext.GuestId == HV_XENLINUX_GUEST_ID)
	{
		DPRINT_INFO(VMBUS, "Skipping SIMP and SIEFP setup since it is already set.");

		simp.AsUINT64 = ReadMsr(HV_X64_MSR_SIMP);
		siefp.AsUINT64 = ReadMsr(HV_X64_MSR_SIEFP);

		DPRINT_DBG(VMBUS, "Simp: %llx, Sifep: %llx", simp.AsUINT64, siefp.AsUINT64);

		// Determine if we are running on xenlinux (ie x2v shim) or native linux
		guestID = ReadMsr(HV_X64_MSR_GUEST_OS_ID);

		if (guestID == HV_LINUX_GUEST_ID)
		{
			gHvContext.synICMessagePage[0] = GetVirtualAddress(simp.BaseSimpGpa << PAGE_SHIFT);
			gHvContext.synICEventPage[0] = GetVirtualAddress(siefp.BaseSiefpGpa << PAGE_SHIFT);
		}
		else
		{
			DPRINT_ERR(VMBUS, "unknown guest id!!");
			goto Cleanup;
		}
		DPRINT_DBG(VMBUS, "MAPPED: Simp: %p, Sifep: %p", gHvContext.synICMessagePage[0], gHvContext.synICEventPage[0]);
	}
	else
	{
		gHvContext.synICMessagePage[0] = PageAlloc(1);
		if (gHvContext.synICMessagePage[0] == NULL)
		{
			DPRINT_ERR(VMBUS, "unable to allocate SYNIC message page!!");
			goto Cleanup;
		}

		gHvContext.synICEventPage[0] = PageAlloc(1);
		if (gHvContext.synICEventPage[0] == NULL)
		{
			DPRINT_ERR(VMBUS, "unable to allocate SYNIC event page!!");
			goto Cleanup;
		}

		//
		// Setup the Synic's message page
		//
		simp.AsUINT64 = ReadMsr(HV_X64_MSR_SIMP);
		simp.SimpEnabled = 1;
		simp.BaseSimpGpa = GetPhysicalAddress(gHvContext.synICMessagePage[0]) >> PAGE_SHIFT;

		DPRINT_DBG(VMBUS, "HV_X64_MSR_SIMP msr set to: %llx", simp.AsUINT64);

		WriteMsr(HV_X64_MSR_SIMP, simp.AsUINT64);

		//
		// Setup the Synic's event page
		//
		siefp.AsUINT64 = ReadMsr(HV_X64_MSR_SIEFP);
		siefp.SiefpEnabled = 1;
		siefp.BaseSiefpGpa = GetPhysicalAddress(gHvContext.synICEventPage[0]) >> PAGE_SHIFT;

		DPRINT_DBG(VMBUS, "HV_X64_MSR_SIEFP msr set to: %llx", siefp.AsUINT64);

		WriteMsr(HV_X64_MSR_SIEFP, siefp.AsUINT64);
	}
	//
    // Setup the interception SINT.
    //
	//WriteMsr((HV_X64_MSR_SINT0 + HV_SYNIC_INTERCEPTION_SINT_INDEX),
    //             interceptionSint.AsUINT64);

    //
    // Setup the shared SINT.
    //
	sharedSint.AsUINT64 = ReadMsr(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT);

	sharedSint.AsUINT64 = 0;
    sharedSint.Vector = irqVector; //HV_SHARED_SINT_IDT_VECTOR + 0x20;
    sharedSint.Masked = FALSE;
    sharedSint.AutoEoi = TRUE;

	DPRINT_DBG(VMBUS, "HV_X64_MSR_SINT1 msr set to: %llx", sharedSint.AsUINT64);

	WriteMsr(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, sharedSint.AsUINT64);

	// Enable the global synic bit
	sctrl.AsUINT64 = ReadMsr(HV_X64_MSR_SCONTROL);
	sctrl.Enable = 1;

    WriteMsr(HV_X64_MSR_SCONTROL, sctrl.AsUINT64);

	gHvContext.SynICInitialized = TRUE;

	DPRINT_EXIT(VMBUS);

	return ret;

Cleanup:
	ret = -1;

	if (gHvContext.GuestId == HV_LINUX_GUEST_ID)
	{
		if (gHvContext.synICEventPage[0])
		{
			PageFree(gHvContext.synICEventPage[0],1);
		}

		if (gHvContext.synICMessagePage[0])
		{
			PageFree(gHvContext.synICMessagePage[0], 1);
		}
	}

	DPRINT_EXIT(VMBUS);

	return ret;

}

/*++

Name:
	HvSynicCleanup()

Description:
	Cleanup routine for HvSynicInit().

--*/
void
HvSynicCleanup(
	void
	)
{
    HV_SYNIC_SINT	sharedSint;
	HV_SYNIC_SIMP	simp;
	HV_SYNIC_SIEFP	siefp;

	DPRINT_ENTER(VMBUS);

	if (!gHvContext.SynICInitialized)
	{
		DPRINT_EXIT(VMBUS);
		return;
	}

	sharedSint.AsUINT64 = ReadMsr(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT);

	sharedSint.Masked = 1;

	// Disable the interrupt
    WriteMsr(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, sharedSint.AsUINT64);

	// Disable and free the resources only if we are running as native linux
	// since in xenlinux, we are sharing the resources with the x2v shim
	if (gHvContext.GuestId == HV_LINUX_GUEST_ID)
	{
		simp.AsUINT64 = ReadMsr(HV_X64_MSR_SIMP);
		simp.SimpEnabled = 0;
		simp.BaseSimpGpa = 0;

		WriteMsr(HV_X64_MSR_SIMP, simp.AsUINT64);

		siefp.AsUINT64 = ReadMsr(HV_X64_MSR_SIEFP);
		siefp.SiefpEnabled = 0;
		siefp.BaseSiefpGpa = 0;

		WriteMsr(HV_X64_MSR_SIEFP, siefp.AsUINT64);

		PageFree(gHvContext.synICMessagePage[0], 1);
		PageFree(gHvContext.synICEventPage[0], 1);
	}

	DPRINT_EXIT(VMBUS);
}


// eof