text: /*-
   * 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.
   *
   * $FreeBSD: src/sys/compat/ndis/subr_hal.c,v 1.34 2012/11/17 01:51:26 svnexp Exp $
   */
  
  #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 <sys/bus.h>
  #include <sys/rman.h>
  
  #include <emulation/ndis/pe_var.h>
  #include <emulation/ndis/resource_var.h>
  #include <emulation/ndis/cfg_var.h>
  #include <emulation/ndis/ntoskrnl_var.h>
  #include <emulation/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 lock disp_lock[NDIS_MAXCPUS];
  
  int
  hal_libinit(void)
  {
  	image_patch_table	*patch;
  	int			i;
  
  	for (i = 0; i < NDIS_MAXCPUS; i++)
  		lockinit(&disp_lock[i], "HAL preemption lock", 0,
  		    LK_CANRECURSE);
  
  	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(void)
  {
  	image_patch_table	*patch;
  	int			i;
  
  	for (i = 0; i < NDIS_MAXCPUS; i++)
  		lockuninit(&disp_lock[i]);
  
  	patch = hal_functbl;
  	while (patch->ipt_func != NULL) {
  		windrv_unwrap(patch->ipt_wrap);
  		patch++;
  	}
  
  	return (0);
  }
  
  static void
  KeStallExecutionProcessor(uint32_t usecs)
  {
  	DELAY(usecs);
  }
  
  static void
  WRITE_PORT_ULONG(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(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(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(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(uint16_t *port)
  {
  	return (bus_space_read_2(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port));
  }
  
  static uint32_t
  READ_PORT_ULONG(uint32_t *port)
  {
  	return (bus_space_read_4(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port));
  }
  
  static uint8_t
  READ_PORT_UCHAR(uint8_t *port)
  {
  	return (bus_space_read_1(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port));
  }
  
  static void
  READ_PORT_BUFFER_ULONG(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(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(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 TDPRI_INT_HIGH, 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(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(void)
  {
  	if (lockstatus(&disp_lock[curthread->td_gd->gd_cpuid], curthread))
  		return (DISPATCH_LEVEL);
  	return (PASSIVE_LEVEL);
  }
  
  static uint64_t
  KeQueryPerformanceCounter(uint64_t *freq)
  {
  	if (freq != NULL)
  		*freq = hz;
  
  	return ((uint64_t)ticks);
  }
  
  uint8_t
  KfRaiseIrql(uint8_t irql)
  {
  	uint8_t			oldirql;
  
  #if 0 /* XXX swildner */
  		sched_pin();
  #endif
  	oldirql = KeGetCurrentIrql();
  
  	/* I am so going to hell for this. */
  	if (oldirql > irql)
  		panic("IRQL_NOT_LESS_THAN_OR_EQUAL");
  
  	if (oldirql != DISPATCH_LEVEL)
  		lockmgr(&disp_lock[curthread->td_gd->gd_cpuid], LK_EXCLUSIVE);
  #if 0 /* XXX swildner */
  	else
  		sched_unpin();
  #endif
  
  /*kprintf("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");
  
  	lockmgr(&disp_lock[curthread->td_gd->gd_cpuid], LK_RELEASE);
  #if 0 /* XXX swildner */
  	sched_unpin();
  #endif
  }
  
  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(void)
  {
  	kprintf("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 }
  };
  