1258 lines
40 KiB
ArmAsm
1258 lines
40 KiB
ArmAsm
// TITLE("Interlocked Support")
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//++
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//
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// Copyright (c) 1990 Microsoft Corporation
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// Copyright (c) 1992 Digital Equipment Corporation
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//
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// Module Name:
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//
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// intrlock.s
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//
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// Abstract:
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//
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// This module implements functions to support interlocked operations.
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// Interlocked operations can only operate on nonpaged data and the
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// specified spinlock cannot be used for any other purpose.
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//
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// Author:
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//
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// David N. Cutler (davec) 26-Mar-1990
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//
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// Environment:
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//
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// Kernel mode.
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//
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// Revision History:
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//
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// Thomas Van Baak (tvb) 18-May-1992
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//
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// Adapted for Alpha AXP.
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//
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//--
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#include "ksalpha.h"
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SBTTL("Interlocked Add Large Integer")
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//++
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//
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// LARGE_INTEGER
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// ExInterlockedAddLargeInteger (
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// IN PLARGE_INTEGER Addend,
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// IN LARGE_INTEGER Increment,
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// IN PKSPIN_LOCK Lock
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// )
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//
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// Routine Description:
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//
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// This function performs an interlocked add of an increment value to an
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// addend variable of type large integer. The initial value of the addend
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// variable is returned as the function value.
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//
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// Arguments:
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//
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// Addend (a0) - Supplies a pointer to a variable whose value is to be
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// adjusted by the increment value.
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//
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// Increment (a1) - Supplies the increment value to be added to the
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// addend variable.
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//
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// Lock (a2) - Supplies a pointer to a spin lock to be used to synchronize
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// access to the addend variable.
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//
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// Return Value:
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//
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// The result of the interlocked large integer add.
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//
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// Implementation Note:
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//
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// The specification of this function requires that the given lock must be
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// used to synchronize the update even though on Alpha the operation can
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// actually done atomically without using the specified lock.
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//
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//--
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LEAF_ENTRY(ExInterlockedAddLargeInteger)
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10: DISABLE_INTERRUPTS
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#if !defined(NT_UP)
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ldl_l t0, 0(a2) // get current lock value - locked
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bne t0, 20f // if ne, spin lock still owned
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mov a2, t0 // set ownership value (lock address)
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stl_c t0, 0(a2) // set spin lock owned - conditionally
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beq t0, 20f // if lock_flag eq zero, store failed
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mb // synchronize the read of the addend
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// after the spinlock is acquired
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#endif
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ldq t0, 0(a0) // get addend
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addq t0, a1, v0 // do the add
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stq v0, 0(a0) // store result
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#if !defined(NT_UP)
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mb // synchronize the write of the addend
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// before the spinlock is released
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stl zero, 0(a2) // set spin lock not owned
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#endif
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ENABLE_INTERRUPTS // turn on interrupts
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ret zero, (ra) // return
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#if !defined(NT_UP)
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//
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// We expect the store conditional will usually succeed the first time so it
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// is faster to branch forward (predicted not taken) to here and then branch
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// backward (predicted taken) to where we wanted to go.
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//
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20: ENABLE_INTERRUPTS // turn on interrupts
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22: ldl t0, 0(a2) // read current lock value
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beq t0, 10b // try spinlock again if available
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br zero, 22b // spin in cache until available
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#endif
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.end ExInterlockedAddLargeInteger
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SBTTL("Interlocked Add Large Statistic")
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//++
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//
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// VOID
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// ExInterlockedAddLargeStatistic (
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// IN PLARGE_INTEGER Addend,
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// IN ULONG Increment
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// )
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//
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// Routine Description:
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//
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// This function performs an interlocked add of an increment value to an
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// addend variable of type large integer.
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//
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// Arguments:
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//
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// Addend (a0) - Supplies a pointer to a variable whose value is to be
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// adjusted by the increment value.
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//
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// Increment (a1) - Supplies the increment value to be added to the
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// addend variable.
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//
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// Return Value:
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//
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// None.
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//
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// Implementation Note:
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//
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// The specification of this function requires that the given lock must be
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// used to synchronize the update even though on Alpha the operation can
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// actually done atomically without using the specified lock.
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//
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//--
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LEAF_ENTRY(ExInterlockedAddLargeStatistic)
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zap a1, 0xf0, a1 // zero extend increment value
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10: ldq_l t0, 0(a0) // get addend
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addq t0, a1, t0 // do the add
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stq_c t0, 0(a0) // store result
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beq t0, 20f // if eq, store conditional failed
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ret zero, (ra) // return
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//
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// We expect the store conditional will usually succeed the first time so it
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// is faster to branch forward (predicted not taken) to here and then branch
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// backward (predicted taken) to where we wanted to go.
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//
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20: br zero, 10b // try again
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.end ExInterlockedAddLargeStatistic
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SBTTL("Interlocked Add Unsigned Long")
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//++
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//
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// ULONG
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// ExInterlockedAddUlong (
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// IN PULONG Addend,
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// IN ULONG Increment,
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// IN PKSPIN_LOCK Lock
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// )
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//
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// Routine Description:
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//
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// This function performs an interlocked add of an increment value to an
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// addend variable of type unsigned long. The initial value of the addend
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// variable is returned as the function value.
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//
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// Arguments:
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//
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// Addend (a0) - Supplies a pointer to a variable whose value is to be
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// adjusted by the increment value.
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//
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// Increment (a1) - Supplies the increment value to be added to the
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// addend variable.
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//
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// Lock (a2) - Supplies a pointer to a spin lock to be used to synchronize
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// access to the addend variable.
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//
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// Return Value:
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//
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// The initial value of the addend variable.
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//
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// Implementation Note:
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//
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// The specification of this function requires that the given lock must be
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// used to synchronize the update even though on Alpha the operation can
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// actually done atomically without using the specified lock.
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//
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//--
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LEAF_ENTRY(ExInterlockedAddUlong)
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10: DISABLE_INTERRUPTS // (PALcode) v0 is clobbered
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#if !defined(NT_UP)
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ldl_l t0, 0(a2) // get current lock value - locked
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bne t0, 20f // if ne, spin lock still owned
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mov a2, t0 // set ownership value (lock address)
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stl_c t0, 0(a2) // set spin lock owned - conditionally
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beq t0, 20f // if lock_flag eq zero, store failed
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mb // synchronize the read of the addend
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// after the spinlock is acquired
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#endif
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//
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// Set the return value in t0 for now since PALcode may use v0.
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//
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ldl t0, 0(a0) // get addend value (return value also)
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addl t0, a1, t1 // compute adjusted value
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stl t1, 0(a0) // store updated value
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#if !defined(NT_UP)
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mb // synchronize the update of the addend
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// before the spinlock is released
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stl zero, 0(a2) // set spin lock not owned
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#endif
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ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
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mov t0, v0 // set return value
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ret zero, (ra) // return
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#if !defined(NT_UP)
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//
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// We expect the store conditional will usually succeed the first time so it
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// is faster to branch forward (predicted not taken) to here and then branch
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// backward (predicted taken) to where we wanted to go.
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//
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20:
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ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
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22: ldl t0, 0(a2) // read current lock value
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beq t0, 10b // try spinlock again if available
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br zero, 22b // spin in cache until available
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#endif
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.end ExInterlockedAddUlong
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SBTTL("Interlocked Exchange Unsigned Long")
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//++
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//
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// ULONG
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// ExInterlockedExchangeUlong (
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// IN PULONG Source,
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// IN ULONG Value,
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// IN PKSPIN_LOCK Lock
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// )
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//
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// Routine Description:
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//
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// This function performs an interlocked exchange of a longword value with
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// a longword in memory and returns the memory value.
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//
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// N.B. There is an alternate entry point provided for this routine which
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// is ALPHA target specific and whose prototype does not include the
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// spinlock parameter. Since the routine never refers to the spinlock
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// parameter, no additional code is required.
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//
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// Arguments:
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//
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// Source (a0) - Supplies a pointer to a variable whose value is to be
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// exchanged.
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//
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// Value (a1) - Supplies the value to exchange with the source value.
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//
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// Lock (a2) - Supplies a pointer to a spin lock to be used to synchronize
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// access to the source variable.
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//
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// Return Value:
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//
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// The source value is returned as the function value.
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//
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//--
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LEAF_ENTRY(ExInterlockedExchangeUlong)
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ALTERNATE_ENTRY(ExAlphaInterlockedExchangeUlong)
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10: ldl_l v0,0(a0) // get current source value
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xor a1,zero,t0 // set exchange value
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stl_c t0,0(a0) // replace source value
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beq t0,20f // if lock_flag eq zero, store failed
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ret zero,(ra) // else/ return old value to caller
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//
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// We expect the store conditional will usually succeed the first time so it
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// is faster to branch forward (predicted not taken) to here and then branch
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// backward (predicted taken) to where we wanted to go.
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//
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20: br zero,10b // go try spin lock again
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.end ExInterlockedExchangeUlong
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SBTTL("Interlocked Exchange Add Large Integer")
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//++
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//
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// LARGE_INTEGER
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// ExpInterlockedExchangeAddLargeInteger (
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// IN PLARGE_INTEGER Addend,
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// IN LARGE_INTEGER Increment
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// )
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//
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// Routine Description:
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//
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// This function performs an interlocked add of an increment value to an
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// addend variable of type large integer. The initial value of the addend
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// variable is returned as the function value.
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//
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// Arguments:
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//
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// Addend (a0) - Supplies a pointer to a variable whose value is to be
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// adjusted by the increment value.
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//
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// Increment (a1) - Supplies the increment value to be added to the
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// addend variable.
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//
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// Return Value:
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//
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// The initial value of the addend variable
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//
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//--
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LEAF_ENTRY(ExpInterlockedExchangeAddLargeInteger)
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10:
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ldq_l v0, 0(a0) // get addend value
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addq a1, v0, t1 // add increment
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stq_c t1, 0(a0) // store addend value
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beq t1, 15f // if eq, store conditional failed
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ret zero, (ra) // return old value to caller
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15:
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beq zero, 10b // retry
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.end ExpInterlockedExchangeAddLargeInteger
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SBTTL("Interlocked Decrement Long")
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//++
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//
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// INTERLOCKED_RESULT
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// ExInterlockedDecrementLong (
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// IN PLONG Addend,
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// IN PKSPIN_LOCK Lock
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// )
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//
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// Routine Description:
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//
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// This function performs an interlocked decrement on an addend variable
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// of type signed long. The sign and whether the result is zero is returned
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// as the function value.
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//
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// N.B. There is an alternate entry point provided for this routine which
|
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// is ALPHA target specific and whose prototype does not include the
|
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// spinlock parameter. Since the routine never refers to the spinlock
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// parameter, no additional code is required.
|
||
//
|
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// Arguments:
|
||
//
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// Addend (a0) - Supplies a pointer to a variable whose value is to be
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// decremented.
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//
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// Lock (a1) - Supplies a pointer to a spin lock to be used to synchronize
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// access to the addend variable.
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//
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// Return Value:
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//
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// RESULT_NEGATIVE is returned if the resultant addend value is negative.
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// RESULT_ZERO is returned if the resultant addend value is zero.
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// RESULT_POSITIVE is returned if the resultant addend value is positive.
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//
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// Implementation Note:
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||
//
|
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// The specification of this function does not require that the given lock
|
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// be used to synchronize the update as long as the update is synchronized
|
||
// somehow. On Alpha a single load locked-store conditional does the job.
|
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//
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//--
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LEAF_ENTRY(ExInterlockedDecrementLong)
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ALTERNATE_ENTRY(ExAlphaInterlockedDecrementLong)
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10: ldl_l v0, 0(a0) // get current addend value - locked
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subl v0, 1, v0 // decrement addend value
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mov v0, t0 // copy updated value to t0 for store
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stl_c t0, 0(a0) // store updated value - conditionally
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beq t0, 20f // if lock_flag eq zero, store failed
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//
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// Determine the INTERLOCKED_RESULT value based on the updated addend value.
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// N.B. RESULT_ZERO = 0, RESULT_NEGATIVE = 1, RESULT_POSITIVE = 2.
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//
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sra v0, 63, t0 // replicate the sign bit to every bit
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addl t0, 2, t0 // if t0 = 0 return 2, if -1 return 1
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cmovne v0, t0, v0 // if v0 = 0 return 0
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ret zero, (ra) // return
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//
|
||
// We expect the store conditional will usually succeed the first time so it
|
||
// is faster to branch forward (predicted not taken) to here and then branch
|
||
// backward (predicted taken) to where we wanted to go.
|
||
//
|
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20: br zero, 10b // go try spin lock again
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.end ExInterlockedDecrementLong
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SBTTL("Interlocked Increment Long")
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//++
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//
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// INTERLOCKED_RESULT
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// ExInterlockedIncrementLong (
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// IN PLONG Addend,
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// IN PKSPIN_LOCK Lock
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// )
|
||
//
|
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// Routine Description:
|
||
//
|
||
// This function performs an interlocked increment on an addend variable
|
||
// of type signed long. The sign and whether the result is zero is returned
|
||
// as the function value.
|
||
//
|
||
// N.B. There is an alternate entry point provided for this routine which
|
||
// is ALPHA target specific and whose prototype does not include the
|
||
// spinlock parameter. Since the routine never refers to the spinlock
|
||
// parameter, no additional code is required.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// Addend (a0) - Supplies a pointer to a variable whose value is to be
|
||
// incremented.
|
||
//
|
||
// Lock (a1) - Supplies a pointer to a spin lock to be used to synchronize
|
||
// access to the addend variable.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// RESULT_NEGATIVE is returned if the resultant addend value is negative.
|
||
// RESULT_ZERO is returned if the resultant addend value is zero.
|
||
// RESULT_POSITIVE is returned if the resultant addend value is positive.
|
||
//
|
||
// Implementation Note:
|
||
//
|
||
// The specification of this function does not require that the given lock
|
||
// be used to synchronize the update as long as the update is synchronized
|
||
// somehow. On Alpha a single load locked-store conditional does the job.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(ExInterlockedIncrementLong)
|
||
|
||
ALTERNATE_ENTRY(ExAlphaInterlockedIncrementLong)
|
||
|
||
10: ldl_l v0, 0(a0) // get current addend value - locked
|
||
addl v0, 1, v0 // increment addend value
|
||
mov v0, t0 // copy updated value to t0 for store
|
||
stl_c t0, 0(a0) // store updated value - conditionally
|
||
beq t0, 20f // if lock_flag eq zero, store failed
|
||
|
||
//
|
||
// Determine the INTERLOCKED_RESULT value based on the updated addend value.
|
||
// N.B. RESULT_ZERO = 0, RESULT_NEGATIVE = 1, RESULT_POSITIVE = 2.
|
||
//
|
||
|
||
sra v0, 63, t0 // replicate the sign bit to every bit
|
||
addl t0, 2, t0 // if t0 = 0 return 2, if -1 return 1
|
||
cmovne v0, t0, v0 // if v0 = 0 return 0
|
||
|
||
ret zero, (ra) // return
|
||
|
||
//
|
||
// We expect the store conditional will usually succeed the first time so it
|
||
// is faster to branch forward (predicted not taken) to here and then branch
|
||
// backward (predicted taken) to where we wanted to go.
|
||
//
|
||
|
||
20: br zero, 10b // go try spin lock again
|
||
|
||
.end ExInterlockedIncrementLong
|
||
|
||
SBTTL("Interlocked Insert Head List")
|
||
//++
|
||
//
|
||
// PLIST_ENTRY
|
||
// ExInterlockedInsertHeadList (
|
||
// IN PLIST_ENTRY ListHead,
|
||
// IN PLIST_ENTRY ListEntry,
|
||
// IN PKSPIN_LOCK Lock
|
||
// )
|
||
//
|
||
// Routine Description:
|
||
//
|
||
// This function inserts an entry at the head of a doubly linked list
|
||
// so that access to the list is synchronized in a multiprocessor system.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// ListHead (a0) - Supplies a pointer to the head of the doubly linked
|
||
// list into which an entry is to be inserted.
|
||
//
|
||
// ListEntry (a1) - Supplies a pointer to the entry to be inserted at the
|
||
// head of the list.
|
||
//
|
||
// Lock (a2) - Supplies a pointer to a spin lock to be used to synchronize
|
||
// access to the list.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// Pointer to entry that was at the head of the list or NULL if the list
|
||
// was empty.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(ExInterlockedInsertHeadList)
|
||
|
||
10: DISABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
ldl_l t0, 0(a2) // get current lock value - locked
|
||
bne t0, 20f // if ne, spin lock still owned
|
||
mov a2, t0 // set ownership value (lock address)
|
||
stl_c t0, 0(a2) // set spin lock owned - conditionally
|
||
beq t0, 20f // if lock_flag eq zero, store failed
|
||
mb // synchronize subsequent reads after
|
||
// the spinlock is acquired
|
||
|
||
#endif
|
||
|
||
//
|
||
// Set the return value in t0 for now since PALcode may use v0.
|
||
//
|
||
|
||
ldl t0, LsFlink(a0) // get address of next entry (return value also)
|
||
stl t0, LsFlink(a1) // store next link in entry
|
||
stl a0, LsBlink(a1) // store previous link in entry
|
||
stl a1, LsBlink(t0) // store previous link in next
|
||
stl a1, LsFlink(a0) // store next link in head
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
mb // sychronize updates to the list
|
||
// befor the spinlock is released
|
||
stl zero, 0(a2) // set spin lock not owned
|
||
|
||
#endif
|
||
|
||
ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
xor t0, a0, v0 // if t0=a0, list empty, set v0 to NULL
|
||
cmovne v0, t0, v0 // else return previous entry at head
|
||
ret zero, (ra) // return
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
//
|
||
// We expect the store conditional will usually succeed the first time so it
|
||
// is faster to branch forward (predicted not taken) to here and then branch
|
||
// backward (predicted taken) to where we wanted to go.
|
||
//
|
||
|
||
20: ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
22: ldl t0, 0(a2) // read current lock value
|
||
beq t0, 10b // try spinlock again if available
|
||
br zero, 22b // spin in cache until available
|
||
|
||
|
||
#endif
|
||
|
||
.end ExInterlockedInsertHeadList
|
||
|
||
SBTTL("Interlocked Insert Tail List")
|
||
//++
|
||
//
|
||
// PLIST_ENTRY
|
||
// ExInterlockedInsertTailList (
|
||
// IN PLIST_ENTRY ListHead,
|
||
// IN PLIST_ENTRY ListEntry,
|
||
// IN PKSPIN_LOCK Lock
|
||
// )
|
||
//
|
||
// Routine Description:
|
||
//
|
||
// This function inserts an entry at the tail of a doubly linked list
|
||
// so that access to the list is synchronized in a multiprocessor system.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// ListHead (a0) - Supplies a pointer to the head of the doubly linked
|
||
// list into which an entry is to be inserted.
|
||
//
|
||
// ListEntry (a1) - Supplies a pointer to the entry to be inserted at the
|
||
// tail of the list.
|
||
//
|
||
// Lock (a2) - Supplies a pointer to a spin lock to be used to synchronize
|
||
// access to the list.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// Pointer to entry that was at the tail of the list or NULL if the list
|
||
// was empty.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(ExInterlockedInsertTailList)
|
||
|
||
10: DISABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
ldl_l t0, 0(a2) // get current lock value - locked
|
||
bne t0, 20f // if ne, spin lock still owned
|
||
mov a2, t0 // set ownership value (lock address)
|
||
stl_c t0, 0(a2) // set spin lock owned - conditionally
|
||
beq t0, 20f // if lock_flag eq zero, store failed
|
||
mb // sychronize subsequent reads after
|
||
// the spinlock is acquired
|
||
|
||
#endif
|
||
|
||
//
|
||
// Set the return value in t0 for now since PALcode may use v0.
|
||
//
|
||
|
||
ldl t0, LsBlink(a0) // get address of previous entry (return value also)
|
||
stl a0, LsFlink(a1) // store next link in entry
|
||
stl t0, LsBlink(a1) // store previous link in entry
|
||
stl a1, LsBlink(a0) // store previous link in next
|
||
stl a1, LsFlink(t0) // store next link in head
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
mb // sychronize updates to the list
|
||
// before the spinlock is released
|
||
stl zero, 0(a2) // set spin lock not owned
|
||
|
||
#endif
|
||
|
||
ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
xor t0, a0, v0 // if t0=a0, list empty, set v0 to NULL
|
||
cmovne v0, t0, v0 // else return previous entry at tail
|
||
ret zero, (ra) // return
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
//
|
||
// We expect the store conditional will usually succeed the first time so it
|
||
// is faster to branch forward (predicted not taken) to here and then branch
|
||
// backward (predicted taken) to where we wanted to go.
|
||
//
|
||
|
||
20: ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
22: ldl t0, 0(a2) // read current lock value
|
||
beq t0, 10b // try spinlock again if available
|
||
br zero, 22b // spin in cache until available
|
||
|
||
#endif
|
||
|
||
.end ExInterlockedInsertTailList
|
||
|
||
SBTTL("Interlocked Remove Head List")
|
||
//++
|
||
//
|
||
// PLIST_ENTRY
|
||
// ExInterlockedRemoveHeadList (
|
||
// IN PLIST_ENTRY ListHead,
|
||
// IN PKSPIN_LOCK Lock
|
||
// )
|
||
//
|
||
// Routine Description:
|
||
//
|
||
// This function removes an entry from the head of a doubly linked list
|
||
// so that access to the list is synchronized in a multiprocessor system.
|
||
// If there are no entries in the list, then a value of NULL is returned.
|
||
// Otherwise, the address of the entry that is removed is returned as the
|
||
// function value.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// ListHead (a0) - Supplies a pointer to the head of the doubly linked
|
||
// list from which an entry is to be removed.
|
||
//
|
||
// Lock (a1) - Supplies a pointer to a spin lock to be used to synchronize
|
||
// access to the list.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// The address of the entry removed from the list, or NULL if the list is
|
||
// empty.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(ExInterlockedRemoveHeadList)
|
||
|
||
10: DISABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
ldl_l t0, 0(a1) // get current lock value - locked
|
||
bne t0, 30f // if ne, spin lock still owned
|
||
mov a1, t0 // set ownership value (lock address)
|
||
stl_c t0, 0(a1) // set spin lock owned - conditionally
|
||
beq t0, 30f // if lock_flag eq zero, store failed
|
||
mb // synchronize subsequent reads after
|
||
// the spinlock is acquired
|
||
|
||
#endif
|
||
|
||
//
|
||
// Set the return value in t0 for now since PALcode may use v0.
|
||
//
|
||
|
||
ldl t2, LsFlink(a0) // get address of next entry
|
||
xor t2, a0, t0 // if t2=a0, list empty, set t0 to NULL
|
||
beq t0, 20f // if eq [NULL], list is empty
|
||
|
||
ldl t1, LsFlink(t2) // get address of next entry
|
||
stl t1, LsFlink(a0) // store address of next in head
|
||
stl a0, LsBlink(t1) // store address of previous in next
|
||
mov t2, t0 // return the address of entry removed
|
||
20: //
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
mb // synchronize writes to the list
|
||
// before the spinlock is released
|
||
stl zero, 0(a1) // set spin lock not owned
|
||
|
||
#endif
|
||
|
||
ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
mov t0, v0 // set return value
|
||
ret zero, (ra) // return
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
//
|
||
// We expect the store conditional will usually succeed the first time so it
|
||
// is faster to branch forward (predicted not taken) to here and then branch
|
||
// backward (predicted taken) to where we wanted to go.
|
||
//
|
||
|
||
30: ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
32: ldl t0, 0(a1) // read current lock value
|
||
beq t0, 10b // try spinlock again if available
|
||
br zero, 32b // spin in cache until available
|
||
|
||
#endif
|
||
|
||
.end ExInterlockedRemoveHeadList
|
||
|
||
SBTTL("Interlocked Pop Entry List")
|
||
//++
|
||
//
|
||
// PSINGLE_LIST_ENTRY
|
||
// ExInterlockedPopEntryList (
|
||
// IN PSINGLE_LIST_ENTRY ListHead,
|
||
// IN PKSPIN_LOCK Lock
|
||
// )
|
||
//
|
||
// Routine Description:
|
||
//
|
||
// This function removes an entry from the head of a singly linked list
|
||
// so that access to the list is synchronized in a multiprocessor system.
|
||
// If there are no entries in the list, then a value of NULL is returned.
|
||
// Otherwise, the address of the entry that is removed is returned as the
|
||
// function value.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// ListHead (a0) - Supplies a pointer to the head of the singly linked
|
||
// list from which an entry is to be removed.
|
||
//
|
||
// Lock (a1) - Supplies a pointer to a spin lock to be used to synchronize
|
||
// access to the list.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// The address of the entry removed from the list, or NULL if the list is
|
||
// empty.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(ExInterlockedPopEntryList)
|
||
|
||
10: DISABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
ldl_l t0, 0(a1) // get current lock value - locked
|
||
bne t0, 30f // if ne, spin lock still owned
|
||
mov a1, t0 // set ownership value (lock address)
|
||
stl_c t0, 0(a1) // set spin lock owned - conditionally
|
||
beq t0, 30f // if lock_flag eq zero, store failed
|
||
mb // synchronize subsequent reads after
|
||
// the spinlock is acquired
|
||
|
||
#endif
|
||
|
||
//
|
||
// Set the return value in t0 for now since PALcode may use v0.
|
||
//
|
||
|
||
ldl t0, 0(a0) // get address of next entry (return value also)
|
||
beq t0, 20f // if eq [NULL], list is empty
|
||
|
||
ldl t1, 0(t0) // get address of next entry
|
||
stl t1, 0(a0) // store address of next in head
|
||
20: //
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
mb // synchronize writes to the list
|
||
// before the spinlock is released
|
||
stl zero, 0(a1) // set spin lock not owned
|
||
|
||
#endif
|
||
|
||
ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
mov t0, v0 // set return value
|
||
ret zero, (ra) // return
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
//
|
||
// We expect the store conditional will usually succeed the first time so it
|
||
// is faster to branch forward (predicted not taken) to here and then branch
|
||
// backward (predicted taken) to where we wanted to go.
|
||
//
|
||
|
||
30: ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
32: ldl t0, 0(a1) // read current lock value
|
||
beq t0, 10b // try spinlock again if available
|
||
br zero, 32b // spin in cache until available
|
||
|
||
#endif
|
||
|
||
.end ExInterlockedPopEntryList
|
||
|
||
SBTTL("Interlocked Push Entry List")
|
||
//++
|
||
//
|
||
// PSINGLE_LIST_ENTRY
|
||
// ExInterlockedPushEntryList (
|
||
// IN PSINGLE_LIST_ENTRY ListHead,
|
||
// IN PSINGLE_LIST_ENTRY ListEntry,
|
||
// IN PKSPIN_LOCK Lock
|
||
// )
|
||
//
|
||
// Routine Description:
|
||
//
|
||
// This function inserts an entry at the head of a singly linked list
|
||
// so that access to the list is synchronized in a multiprocessor system.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// ListHead (a0) - Supplies a pointer to the head of the singly linked
|
||
// list into which an entry is to be inserted.
|
||
//
|
||
// ListEntry (a1) - Supplies a pointer to the entry to be inserted at the
|
||
// head of the list.
|
||
//
|
||
// Lock (a2) - Supplies a pointer to a spin lock to be used to synchronize
|
||
// access to the list.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// Previous contents of ListHead. NULL implies list went from empty
|
||
// to not empty.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(ExInterlockedPushEntryList)
|
||
|
||
10: DISABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
ldl_l t0, 0(a2) // get current lock value - locked
|
||
bne t0, 20f // if ne, spin lock still owned
|
||
mov a2, t0 // set ownership value (lock address)
|
||
stl_c t0, 0(a2) // set spin lock owned - conditionally
|
||
beq t0, 20f // if lock_flag eq zero, store failed
|
||
mb // synchronize subsequent reads after
|
||
// the spinlock is acquired
|
||
|
||
#endif
|
||
|
||
//
|
||
// Set the return value in t0 for now since PALcode may use v0.
|
||
//
|
||
|
||
ldl t0, 0(a0) // get address of first entry (return value also)
|
||
stl t0, 0(a1) // set address of next in new entry
|
||
stl a1, 0(a0) // set address of first entry
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
mb // synchronize writes to the list
|
||
// before the spinlock is released
|
||
stl zero, 0(a2) // set spin lock not owned
|
||
|
||
#endif
|
||
|
||
ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
mov t0, v0 // set return value
|
||
ret zero, (ra) // return
|
||
|
||
#if !defined(NT_UP)
|
||
|
||
//
|
||
// We expect the store conditional will usually succeed the first time so it
|
||
// is faster to branch forward (predicted not taken) to here and then branch
|
||
// backward (predicted taken) to where we wanted to go.
|
||
//
|
||
|
||
20: ENABLE_INTERRUPTS // (PALcode) v0 is clobbered
|
||
|
||
22: ldl t0, 0(a2) // read current lock value
|
||
beq t0, 10b // try spinlock again if available
|
||
br zero, 22b // spin in cache until available
|
||
|
||
#endif
|
||
.end ExInterlockedPushEntryList
|
||
|
||
SBTTL("Interlocked Compare Exchange")
|
||
//++
|
||
//
|
||
// PVOID
|
||
// InterlockedCompareExchange (
|
||
// IN OUT PVOID *Destination,
|
||
// IN PVOID Exchange,
|
||
// IN PVOID Comperand
|
||
// )
|
||
//
|
||
// Routine Description:
|
||
//
|
||
// This function performs an interlocked compare of the destination
|
||
// value with the comperand value. If the destination value is equal
|
||
// to the comperand value, then the exchange value is stored in the
|
||
// destination. Otherwise, no opeation is performed.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// Destination (a0) - Supplies a pointer to the destination value.
|
||
//
|
||
// Exchange (a1) - Supplies the exchange.
|
||
//
|
||
// Comperand (a2) - Supplies the comperand value.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// The initial destination value is returned as the function value.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(InterlockedCompareExchange)
|
||
|
||
10:
|
||
#if !defined(NT_UP)
|
||
mb
|
||
#endif
|
||
ldl_l v0, 0(a0) // get current addend value
|
||
bis a1, zero, t0 // copy exchange value for store
|
||
cmpeq v0, a2, t1 // if ne, operands mismatch
|
||
beq t1, 20f
|
||
stl_c t0, 0(a0) // store updated addend value
|
||
beq t0,25f // if eq, store conditional failed
|
||
#if !defined(NT_UP)
|
||
mb
|
||
#endif
|
||
20: ret zero, (ra) // return
|
||
|
||
//
|
||
// We expect the store conditional will usually succeed the first time so it
|
||
// is faster to branch forward (predicted not taken) to here and then branch
|
||
// backward (predicted taken) to where we wanted to go.
|
||
//
|
||
|
||
25: br zero, 10b // go try spin lock again
|
||
|
||
.end InterlockedCompareExchange
|
||
|
||
SBTTL("Interlocked Exchange Add")
|
||
//++
|
||
//
|
||
// LONG
|
||
// ExInterlockedAdd (
|
||
// IN PLONG Addend,
|
||
// IN ULONG Increment
|
||
// )
|
||
//
|
||
// Routine Description:
|
||
//
|
||
// This function performs an interlocked add of an increment value to an
|
||
// addend variable of type unsigned long. The initial value of the addend
|
||
// variable is returned as the function value.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// Addend (a0) - Supplies a pointer to a variable whose value is to be
|
||
// adjusted by the increment value.
|
||
//
|
||
// Increment (a1) - Supplies the increment value to be added to the
|
||
// addend variable.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// The initial value of the addend variable.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(InterlockedExchangeAdd)
|
||
10:
|
||
#if !defined(NT_UP)
|
||
mb
|
||
#endif
|
||
|
||
ldl_l v0, 0(a0) // get current addend value - locked
|
||
addl v0, a1, t0 // increment addend value
|
||
stl_c t0, 0(a0) // store updated value - conditionally
|
||
beq t0, 20f // if lock_flag eq zero, store failed
|
||
#if !defined(NT_UP)
|
||
mb
|
||
#endif
|
||
ret zero, (ra) // return
|
||
|
||
//
|
||
// We expect the store conditional will usually succeed the first time so it
|
||
// is faster to branch forward (predicted not taken) to here and then branch
|
||
// backward (predicted taken) to where we wanted to go.
|
||
//
|
||
|
||
20: br zero, 10b // go try spin lock again
|
||
|
||
.end InterlockedExchangeAdd
|
||
|
||
|
||
SBTTL("Interlocked Pop Entry Sequenced List")
|
||
//++
|
||
//
|
||
// PSINGLE_LIST_ENTRY
|
||
// ExpInterlockedPopEntrySList (
|
||
// IN PSLIST_HEADER ListHead
|
||
// )
|
||
//
|
||
// Routine Description:
|
||
//
|
||
// This function removes an entry from the front of a sequenced singly
|
||
// linked list so that access to the list is synchronized in a MP system.
|
||
// If there are no entries in the list, then a value of NULL is returned.
|
||
// Otherwise, the address of the entry that is removed is returned as the
|
||
// function value.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// ListHead (a0) - Supplies a pointer to the sequenced listhead from which
|
||
// an entry is to be removed.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// The address of the entry removed from the list, or NULL if the list is
|
||
// empty.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(ExpInterlockedPopEntrySList)
|
||
|
||
10:
|
||
ldq t0, 0(a0) // get next entry address and sequence
|
||
addl t0, zero, v0 // sign extend next entry address
|
||
beq v0, 30f // if eq, list is empty
|
||
srl t0, 32, t1 // shift sequence to low 32-bits
|
||
#if !defined(NT_UP)
|
||
mb // ensure we see updates in the same order
|
||
#endif
|
||
|
||
//
|
||
// N.B. It is possible for the following instruction to fault in the rare
|
||
// case where the first entry in the list is allocated on another
|
||
// processor and free between the time the free pointer is read above
|
||
// and the following instruction. When this happens, the access fault
|
||
// code continues execution by skipping the following instruction.
|
||
// This results in the compare failing and the entire operation is
|
||
// retried.
|
||
//
|
||
ALTERNATE_ENTRY(ExpInterlockedPopEntrySListFault)
|
||
|
||
ldl t5, 0(v0) // get address of successor entry
|
||
zapnot t5, 0xf ,t2 // clear high 32-bits for merge
|
||
ldq_l t3, 0(a0) // reload next entry address and sequence
|
||
ldil t5, 0xffff // decrement list depth and
|
||
addl t1, t5, t1 // increment sequence number
|
||
sll t1, 32, t1 // merge successor address and sequence
|
||
cmpeq t0, t3, t4 // if ne, listhead has changed
|
||
beq t4, 15f //
|
||
bis t1, t2, t1 //
|
||
stq_c t1, 0(a0) // store next entry address and sequence
|
||
beq t1, 15f // if eq, store conditional failed
|
||
|
||
30:
|
||
#if !defined(NT_UP)
|
||
mb // ensure consistent view of memory
|
||
#endif
|
||
ret zero, (ra)
|
||
|
||
15:
|
||
br zero, 10b // retry
|
||
|
||
.end ExpInterlockedPopEntrySList
|
||
|
||
SBTTL("Interlocked Push Entry Sequenced List")
|
||
//++
|
||
//
|
||
// PSINGLE_LIST_ENTRY
|
||
// ExpInterlockedPushEntrySList (
|
||
// IN PSLIST_HEADER ListHead,
|
||
// IN PSINGLE_LIST_ENTRY ListEntry
|
||
// )
|
||
//
|
||
// Routine Description:
|
||
//
|
||
// This function inserts an entry at the head of a sequenced singly linked
|
||
// list so that access to the list is synchronized in an MP system.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// ListHead (a0) - Supplies a pointer to the sequenced listhead into which
|
||
// an entry is to be inserted.
|
||
//
|
||
// ListEntry (a1) - Supplies a pointer to the entry to be inserted at the
|
||
// head of the list.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// Previous contents of ListHead. NULL implies list went from empty
|
||
// to not empty.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(ExpInterlockedPushEntrySList)
|
||
|
||
10:
|
||
ldq t0, 0(a0) // get next entry address and sequence
|
||
addl t0, zero, v0 // sign extend next entry address
|
||
srl t0, 32, t1 // shift sequence to low 32-bits
|
||
stl v0, 0(a1) // set next link in new first entry
|
||
#if !defined(NT_UP)
|
||
mb // ensure all writes (including next link) go
|
||
#endif
|
||
zapnot a1, 0xf, t2 // zero extend new first entry
|
||
ldq_l t3, 0(a0) // reload next entry address and sequence
|
||
ldah t5, 1(zero) // get sequence adjustment value
|
||
addl t1, 1, t1 // increment list depth
|
||
addl t1, t5, t1 // increment sequence number
|
||
sll t1, 32, t1 // merge new first entry address and sequence
|
||
cmpeq t0, t3, t4 // if ne, listhead has changed
|
||
beq t4, 15f //
|
||
bis t1, t2, t2
|
||
stq_c t2, 0(a0) // store next entry address and sequence
|
||
beq t2, 15f // if eq, store conditional failed
|
||
|
||
ret zero, (ra)
|
||
15:
|
||
br zero, 10b // retry
|
||
|
||
.end ExpInterlockedPushEntrySList
|
||
|
||
SBTTL("Interlocked Compare Exchange 64-bits")
|
||
//++
|
||
//
|
||
// ULONGLONG
|
||
// ExpInterlockedCompareExchange64 (
|
||
// IN PULONGLONG Destination,
|
||
// IN PULONGLONG Exchange,
|
||
// IN PULONGLONG Comperand
|
||
// )
|
||
//
|
||
// Routine Description:
|
||
//
|
||
// This function performs an interlocked compare and exchange of 64-bits.
|
||
//
|
||
// Arguments:
|
||
//
|
||
// Destination (a0) - Supplies a pointer to the destination variable.
|
||
//
|
||
// Exchange (a1) - Supplies a pointer to the exchange value.
|
||
//
|
||
// Comperand (a2) - Supplies a pointer to the comperand value.
|
||
//
|
||
// Return Value:
|
||
//
|
||
// The current destination value are returned as the function value.
|
||
//
|
||
//--
|
||
|
||
LEAF_ENTRY(ExpInterlockedCompareExchange64)
|
||
|
||
ldq t0, 0(a1) // get exchange value
|
||
ldq t1, 0(a2) // get comperand value
|
||
10: ldq_l v0, 0(a0) // get current destination value
|
||
bis t0, zero, t2 // set exchange value
|
||
cmpeq v0, t1, t3 // check if current and comperand match
|
||
beq t3, 20f // if eq, current and comperand mismatch
|
||
stq_c t2, 0(a0) // store exchange value
|
||
beq t2, 30f // if eq, store conditional failed
|
||
20: ret zero, (ra)
|
||
|
||
30: br zero, 10b // retry
|
||
|
||
.end ExpInterlockedCompareExchange64
|