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147 | ------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- Copyright (C) 2018, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with System.Machine_Code; use System.Machine_Code;
with Interfaces; use Interfaces;
package body System.BB.Armv6m_Atomic is
-------------
-- PRIMASK --
-------------
function PRIMASK return Unsigned_32 is
R : Unsigned_32;
begin
Asm ("mrs %0, PRIMASK", Outputs => Unsigned_32'Asm_Output ("=r", R),
Volatile => True);
return R;
end PRIMASK;
------------------------
-- Interrupt_Disabled --
------------------------
function Interrupt_Disabled return Boolean
is ((PRIMASK and 1) /= 0);
------------------------
-- Disable_Interrupts --
------------------------
procedure Disable_Interrupts is
begin
Asm ("cpsid i" & ASCII.CR & ASCII.LF
& "dsb" & ASCII.CR & ASCII.LF
& "isb",
Clobber => "memory",
Volatile => True);
end Disable_Interrupts;
-----------------------
-- Enable_Interrupts --
-----------------------
procedure Enable_Interrupts is
begin
Asm ("cpsie i" & ASCII.CR & ASCII.LF
& "dsb" & ASCII.CR & ASCII.LF
& "isb",
Clobber => "memory",
Volatile => True);
end Enable_Interrupts;
----------------------------
-- Sync_Lock_Test_And_Set --
----------------------------
function Sync_Lock_Test_And_Set (Addr : System.Address;
Value : T)
return T
is
Data : T with Address => Addr;
Ret : T;
Already_Disabled : constant Boolean := Interrupt_Disabled;
-- Make sure not to change the status of interrupt control by checking
-- if they are enabled when entering the function.
begin
if not Already_Disabled then
Disable_Interrupts;
end if;
Ret := Data;
Data := Value;
-- If the interrupts were disabled when entering this function, we do
-- not want enable them.
if not Already_Disabled then
Enable_Interrupts;
end if;
return Ret;
end Sync_Lock_Test_And_Set;
--------------------------------
-- Sync_Bool_Compare_And_Swap --
--------------------------------
function Sync_Bool_Compare_And_Swap (Addr : System.Address;
Old_Value : T;
New_Value : T)
return Interfaces.C.char
is
Data : T with Address => Addr;
Ret : Interfaces.C.char;
Already_Disabled : constant Boolean := Interrupt_Disabled;
-- Make sure not to change the status of interrupt control by checking
-- if they are enabled when entering the function.
begin
if not Already_Disabled then
Disable_Interrupts;
end if;
if Data = Old_Value then
Data := New_Value;
Ret := Interfaces.C.char'Succ (Interfaces.C.nul); -- True
else
Ret := Interfaces.C.nul; -- False
end if;
-- If the interrupts were disabled when entering this function, we do
-- not want enable them.
if not Already_Disabled then
Enable_Interrupts;
end if;
return Ret;
end Sync_Bool_Compare_And_Swap;
end System.BB.Armv6m_Atomic;
|