0001 /*
0002 NetWinder Floating Point Emulator
0003 (c) Rebel.COM, 1998,1999
0004
0005 Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
0006
0007 This program is free software; you can redistribute it and/or modify
0008 it under the terms of the GNU General Public License as published by
0009 the Free Software Foundation; either version 2 of the License, or
0010 (at your option) any later version.
0011
0012 This program is distributed in the hope that it will be useful,
0013 but WITHOUT ANY WARRANTY; without even the implied warranty of
0014 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
0015 GNU General Public License for more details.
0016
0017 You should have received a copy of the GNU General Public License
0018 along with this program; if not, write to the Free Software
0019 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
0020 */
0021
0022 static inline unsigned long readRegister(const unsigned int nReg)
0023 {
0024 /* Note: The CPU thinks it has dealt with the current instruction.
0025 As a result the program counter has been advanced to the next
0026 instruction, and points 4 bytes beyond the actual instruction
0027 that caused the invalid instruction trap to occur. We adjust
0028 for this in this routine. LDF/STF instructions with Rn = PC
0029 depend on the PC being correct, as they use PC+8 in their
0030 address calculations. */
0031 struct pt_regs *regs = GET_USERREG();
0032 unsigned int val = regs->uregs[nReg];
0033 if (REG_PC == nReg)
0034 val -= 4;
0035 return val;
0036 }
0037
0038 static inline void
0039 writeRegister(const unsigned int nReg, const unsigned long val)
0040 {
0041 struct pt_regs *regs = GET_USERREG();
0042 regs->uregs[nReg] = val;
0043 }
0044
0045 static inline unsigned long readCPSR(void)
0046 {
0047 return (readRegister(REG_CPSR));
0048 }
0049
0050 static inline void writeCPSR(const unsigned long val)
0051 {
0052 writeRegister(REG_CPSR, val);
0053 }
0054
0055 static inline unsigned long readConditionCodes(void)
0056 {
0057 #ifdef __FPEM_TEST__
0058 return (0);
0059 #else
0060 return (readCPSR() & CC_MASK);
0061 #endif
0062 }
0063
0064 static inline void writeConditionCodes(const unsigned long val)
0065 {
0066 struct pt_regs *regs = GET_USERREG();
0067 unsigned long rval;
0068 /*
0069 * Operate directly on userRegisters since
0070 * the CPSR may be the PC register itself.
0071 */
0072 rval = regs->ARM_cpsr & ~CC_MASK;
0073 regs->ARM_cpsr = rval | (val & CC_MASK);
0074 }
