/*-
 * Copyright (c) 2003
 *	Bill Paul <wpaul@windriver.com>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/types.h>
#include <sys/errno.h>

#include <sys/callout.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/module.h>

#include <sys/systm.h>
#include <machine/bus.h>

#include <sys/bus.h>
#include <sys/rman.h>

#include <compat/ndis/pe_var.h>
#include <compat/ndis/resource_var.h>
#include <compat/ndis/cfg_var.h>
#include <compat/ndis/ntoskrnl_var.h>
#include <compat/ndis/hal_var.h>

static void KeStallExecutionProcessor(uint32_t);
static void WRITE_PORT_BUFFER_ULONG(uint32_t *,
	uint32_t *, uint32_t);
static void WRITE_PORT_BUFFER_USHORT(uint16_t *,
	uint16_t *, uint32_t);
static void WRITE_PORT_BUFFER_UCHAR(uint8_t *,
	uint8_t *, uint32_t);
static void WRITE_PORT_ULONG(uint32_t *, uint32_t);
static void WRITE_PORT_USHORT(uint16_t *, uint16_t);
static void WRITE_PORT_UCHAR(uint8_t *, uint8_t);
static uint32_t READ_PORT_ULONG(uint32_t *);
static uint16_t READ_PORT_USHORT(uint16_t *);
static uint8_t READ_PORT_UCHAR(uint8_t *);
static void READ_PORT_BUFFER_ULONG(uint32_t *,
	uint32_t *, uint32_t);
static void READ_PORT_BUFFER_USHORT(uint16_t *,
	uint16_t *, uint32_t);
static void READ_PORT_BUFFER_UCHAR(uint8_t *,
	uint8_t *, uint32_t);
static uint64_t KeQueryPerformanceCounter(uint64_t *);
static void _KeLowerIrql(uint8_t);
static uint8_t KeRaiseIrqlToDpcLevel(void);
static void dummy (void);

#define NDIS_MAXCPUS 64
static struct mtx disp_lock[NDIS_MAXCPUS];

int
hal_libinit()
{
	image_patch_table	*patch;
	int			i;

	for (i = 0; i < NDIS_MAXCPUS; i++)
		mtx_init(&disp_lock[i], "HAL preemption lock",
		    "HAL lock", MTX_RECURSE|MTX_DEF);

	patch = hal_functbl;
	while (patch->ipt_func != NULL) {
		windrv_wrap((funcptr)patch->ipt_func,
		    (funcptr *)&patch->ipt_wrap,
		    patch->ipt_argcnt, patch->ipt_ftype);
		patch++;
	}

	return (0);
}

int
hal_libfini()
{
	image_patch_table	*patch;
	int			i;

	for (i = 0; i < NDIS_MAXCPUS; i++)
		mtx_destroy(&disp_lock[i]);

	patch = hal_functbl;
	while (patch->ipt_func != NULL) {
		windrv_unwrap(patch->ipt_wrap);
		patch++;
	}

	return (0);
}

static void
KeStallExecutionProcessor(usecs)
	uint32_t		usecs;
{
	DELAY(usecs);
}

static void
WRITE_PORT_ULONG(port, val)
	uint32_t		*port;
	uint32_t		val;
{
	bus_space_write_4(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port, val);
}

static void
WRITE_PORT_USHORT(uint16_t *port, uint16_t val)
{
	bus_space_write_2(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port, val);
}

static void
WRITE_PORT_UCHAR(uint8_t *port, uint8_t val)
{
	bus_space_write_1(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port, val);
}

static void
WRITE_PORT_BUFFER_ULONG(port, val, cnt)
	uint32_t		*port;
	uint32_t		*val;
	uint32_t		cnt;
{
	bus_space_write_multi_4(NDIS_BUS_SPACE_IO, 0x0,
	    (bus_size_t)port, val, cnt);
}

static void
WRITE_PORT_BUFFER_USHORT(port, val, cnt)
	uint16_t		*port;
	uint16_t		*val;
	uint32_t		cnt;
{
	bus_space_write_multi_2(NDIS_BUS_SPACE_IO, 0x0,
	    (bus_size_t)port, val, cnt);
}

static void
WRITE_PORT_BUFFER_UCHAR(port, val, cnt)
	uint8_t			*port;
	uint8_t			*val;
	uint32_t		cnt;
{
	bus_space_write_multi_1(NDIS_BUS_SPACE_IO, 0x0,
	    (bus_size_t)port, val, cnt);
}

static uint16_t
READ_PORT_USHORT(port)
	uint16_t		*port;
{
	return (bus_space_read_2(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port));
}

static uint32_t
READ_PORT_ULONG(port)
	uint32_t		*port;
{
	return (bus_space_read_4(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port));
}

static uint8_t
READ_PORT_UCHAR(port)
	uint8_t			*port;
{
	return (bus_space_read_1(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port));
}

static void
READ_PORT_BUFFER_ULONG(port, val, cnt)
	uint32_t		*port;
	uint32_t		*val;
	uint32_t		cnt;
{
	bus_space_read_multi_4(NDIS_BUS_SPACE_IO, 0x0,
	    (bus_size_t)port, val, cnt);
}

static void
READ_PORT_BUFFER_USHORT(port, val, cnt)
	uint16_t		*port;
	uint16_t		*val;
	uint32_t		cnt;
{
	bus_space_read_multi_2(NDIS_BUS_SPACE_IO, 0x0,
	    (bus_size_t)port, val, cnt);
}

static void
READ_PORT_BUFFER_UCHAR(port, val, cnt)
	uint8_t			*port;
	uint8_t			*val;
	uint32_t		cnt;
{
	bus_space_read_multi_1(NDIS_BUS_SPACE_IO, 0x0,
	    (bus_size_t)port, val, cnt);
}

/*
 * The spinlock implementation in Windows differs from that of FreeBSD.
 * The basic operation of spinlocks involves two steps: 1) spin in a
 * tight loop while trying to acquire a lock, 2) after obtaining the
 * lock, disable preemption. (Note that on uniprocessor systems, you're
 * allowed to skip the first step and just lock out pre-emption, since
 * it's not possible for you to be in contention with another running
 * thread.) Later, you release the lock then re-enable preemption.
 * The difference between Windows and FreeBSD lies in how preemption
 * is disabled. In FreeBSD, it's done using critical_enter(), which on
 * the x86 arch translates to a cli instruction. This masks off all
 * interrupts, and effectively stops the scheduler from ever running
 * so _nothing_ can execute except the current thread. In Windows,
 * preemption is disabled by raising the processor IRQL to DISPATCH_LEVEL.
 * This stops other threads from running, but does _not_ block device
 * interrupts. This means ISRs can still run, and they can make other
 * threads runable, but those other threads won't be able to execute
 * until the current thread lowers the IRQL to something less than
 * DISPATCH_LEVEL.
 *
 * There's another commonly used IRQL in Windows, which is APC_LEVEL.
 * An APC is an Asynchronous Procedure Call, which differs from a DPC
 * (Defered Procedure Call) in that a DPC is queued up to run in
 * another thread, while an APC runs in the thread that scheduled
 * it (similar to a signal handler in a UNIX process). We don't
 * actually support the notion of APCs in FreeBSD, so for now, the
 * only IRQLs we're interested in are DISPATCH_LEVEL and PASSIVE_LEVEL.
 *
 * To simulate DISPATCH_LEVEL, we raise the current thread's priority
 * to PI_REALTIME, which is the highest we can give it. This should,
 * if I understand things correctly, prevent anything except for an
 * interrupt thread from preempting us. PASSIVE_LEVEL is basically
 * everything else.
 *
 * Be aware that, at least on the x86 arch, the Windows spinlock
 * functions are divided up in peculiar ways. The actual spinlock
 * functions are KfAcquireSpinLock() and KfReleaseSpinLock(), and
 * they live in HAL.dll. Meanwhile, KeInitializeSpinLock(),
 * KefAcquireSpinLockAtDpcLevel() and KefReleaseSpinLockFromDpcLevel()
 * live in ntoskrnl.exe. Most Windows source code will call
 * KeAcquireSpinLock() and KeReleaseSpinLock(), but these are just
 * macros that call KfAcquireSpinLock() and KfReleaseSpinLock().
 * KefAcquireSpinLockAtDpcLevel() and KefReleaseSpinLockFromDpcLevel()
 * perform the lock aquisition/release functions without doing the
 * IRQL manipulation, and are used when one is already running at
 * DISPATCH_LEVEL. Make sense? Good.
 *
 * According to the Microsoft documentation, any thread that calls
 * KeAcquireSpinLock() must be running at IRQL <= DISPATCH_LEVEL. If
 * we detect someone trying to acquire a spinlock from DEVICE_LEVEL
 * or HIGH_LEVEL, we panic.
 *
 * Alternate sleep-lock-based spinlock implementation
 * --------------------------------------------------
 *
 * The earlier spinlock implementation was arguably a bit of a hack
 * and presented several problems. It was basically designed to provide
 * the functionality of spinlocks without incurring the wrath of
 * WITNESS. We could get away with using both our spinlock implementation
 * and FreeBSD sleep locks at the same time, but if WITNESS knew what
 * we were really up to, it would have spanked us rather severely.
 *
 * There's another method we can use based entirely on sleep locks.
 * First, it's important to realize that everything we're locking
 * resides inside Project Evil itself: any critical data being locked
 * by drivers belongs to the drivers, and should not be referenced
 * by any other OS code outside of the NDISulator. The priority-based
 * locking scheme has system-wide effects, just like real spinlocks
 * (blocking preemption affects the whole CPU), but since we keep all
 * our critical data private, we can use a simpler mechanism that
 * affects only code/threads directly related to Project Evil.
 *
 * The idea is to create a sleep lock mutex for each CPU in the system.
 * When a CPU running in the NDISulator wants to acquire a spinlock, it
 * does the following:
 * - Pin ourselves to the current CPU
 * - Acquire the mutex for the current CPU
 * - Spin on the spinlock variable using atomic test and set, just like
 *   a real spinlock.
 * - Once we have the lock, we execute our critical code
 *
 * To give up the lock, we do:
 * - Clear the spinlock variable with an atomic op
 * - Release the per-CPU mutex
 * - Unpin ourselves from the current CPU.
 *
 * On a uniprocessor system, this means all threads that access protected
 * data are serialized through the per-CPU mutex. After one thread
 * acquires the 'spinlock,' any other thread that uses a spinlock on the
 * current CPU will block on the per-CPU mutex, which has the same general
 * effect of blocking pre-emption, but _only_ for those threads that are
 * running NDISulator code.
 *
 * On a multiprocessor system, threads on different CPUs all block on
 * their respective per-CPU mutex, and the atomic test/set operation
 * on the spinlock variable provides inter-CPU synchronization, though
 * only for threads running NDISulator code.
 *
 * This method solves an important problem. In Windows, you're allowed
 * to do an ExAllocatePoolWithTag() with a spinlock held, provided you
 * allocate from NonPagedPool. This implies an atomic heap allocation
 * that will not cause the current thread to sleep. (You can't sleep
 * while holding real spinlock: clowns will eat you.) But in FreeBSD,
 * malloc(9) _always_ triggers the acquisition of a sleep lock, even
 * when you use M_NOWAIT. This is not a problem for FreeBSD native
 * code: you're allowed to sleep in things like interrupt threads. But
 * it is a problem with the old priority-based spinlock implementation:
 * even though we get away with it most of the time, we really can't
 * do a malloc(9) after doing a KeAcquireSpinLock() or KeRaiseIrql().
 * With the new implementation, it's not a problem: you're allowed to
 * acquire more than one sleep lock (as long as you avoid lock order
 * reversals).
 *
 * The one drawback to this approach is that now we have a lot of
 * contention on one per-CPU mutex within the NDISulator code. Whether
 * or not this is preferable to the expected Windows spinlock behavior
 * of blocking pre-emption is debatable.
 */

uint8_t
KfAcquireSpinLock(lock)
	kspin_lock		*lock;
{
	uint8_t			oldirql;

	KeRaiseIrql(DISPATCH_LEVEL, &oldirql);
	KeAcquireSpinLockAtDpcLevel(lock);

	return (oldirql);
}

void
KfReleaseSpinLock(kspin_lock *lock, uint8_t newirql)
{
	KeReleaseSpinLockFromDpcLevel(lock);
	KeLowerIrql(newirql);
}

uint8_t
KeGetCurrentIrql()
{
	if (mtx_owned(&disp_lock[curthread->td_oncpu]))
		return (DISPATCH_LEVEL);
	return (PASSIVE_LEVEL);
}

static uint64_t
KeQueryPerformanceCounter(freq)
	uint64_t		*freq;
{
	if (freq != NULL)
		*freq = hz;

	return ((uint64_t)ticks);
}

uint8_t
KfRaiseIrql(uint8_t irql)
{
	uint8_t			oldirql;

	oldirql = KeGetCurrentIrql();

	/* I am so going to hell for this. */
	if (oldirql > irql)
		panic("IRQL_NOT_LESS_THAN");

	if (oldirql != DISPATCH_LEVEL) {
		sched_pin();
		mtx_lock(&disp_lock[curthread->td_oncpu]);
	}
/*printf("RAISE IRQL: %d %d\n", irql, oldirql);*/

	return (oldirql);
}

void
KfLowerIrql(uint8_t oldirql)
{
	if (oldirql == DISPATCH_LEVEL)
		return;

	if (KeGetCurrentIrql() != DISPATCH_LEVEL)
		panic("IRQL_NOT_GREATER_THAN");

	mtx_unlock(&disp_lock[curthread->td_oncpu]);
	sched_unpin();
}

static uint8_t
KeRaiseIrqlToDpcLevel(void)
{
	uint8_t			irql;

	KeRaiseIrql(DISPATCH_LEVEL, &irql);
	return (irql);
}

static void
_KeLowerIrql(uint8_t oldirql)
{
	KeLowerIrql(oldirql);
}

static void dummy()
{
	printf("hal dummy called...\n");
}

image_patch_table hal_functbl[] = {
	IMPORT_SFUNC(KeStallExecutionProcessor, 1),
	IMPORT_SFUNC(WRITE_PORT_ULONG, 2),
	IMPORT_SFUNC(WRITE_PORT_USHORT, 2),
	IMPORT_SFUNC(WRITE_PORT_UCHAR, 2),
	IMPORT_SFUNC(WRITE_PORT_BUFFER_ULONG, 3),
	IMPORT_SFUNC(WRITE_PORT_BUFFER_USHORT, 3),
	IMPORT_SFUNC(WRITE_PORT_BUFFER_UCHAR, 3),
	IMPORT_SFUNC(READ_PORT_ULONG, 1),
	IMPORT_SFUNC(READ_PORT_USHORT, 1),
	IMPORT_SFUNC(READ_PORT_UCHAR, 1),
	IMPORT_SFUNC(READ_PORT_BUFFER_ULONG, 3),
	IMPORT_SFUNC(READ_PORT_BUFFER_USHORT, 3),
	IMPORT_SFUNC(READ_PORT_BUFFER_UCHAR, 3),
	IMPORT_FFUNC(KfAcquireSpinLock, 1),
	IMPORT_FFUNC(KfReleaseSpinLock, 1),
	IMPORT_SFUNC(KeGetCurrentIrql, 0),
	IMPORT_SFUNC(KeQueryPerformanceCounter, 1),
	IMPORT_FFUNC(KfLowerIrql, 1),
	IMPORT_FFUNC(KfRaiseIrql, 1),
	IMPORT_SFUNC(KeRaiseIrqlToDpcLevel, 0),
#undef KeLowerIrql
	IMPORT_SFUNC_MAP(KeLowerIrql, _KeLowerIrql, 1),

	/*
	 * This last entry is a catch-all for any function we haven't
	 * implemented yet. The PE import list patching routine will
	 * use it for any function that doesn't have an explicit match
	 * in this table.
	 */

	{ NULL, (FUNC)dummy, NULL, 0, WINDRV_WRAP_STDCALL },

	/* End of list. */

	{ NULL, NULL, NULL }
};
