tests/kernel/test_fp_sharing/microkernel/src/float_context.h

/* float_context.h - common definitions for the FPU sharing test application */

/*
 * Copyright (c) 2011-2014 Wind River Systems, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _FLOATCONTEXT_H
#define _FLOATCONTEXT_H

/*
 * Each architecture must define the FP_REG_SET and FP_NONVOLATILE_REG_SET
 * structures, and tailor the architecture specific implementations of
 * _LoadAllFloatRegisters(), _StoreAllFloatRegisters(), and
 * _StoreNonVolatileFloatRegisters() to read/write from these structures.
 */

#if defined(CONFIG_ISA_IA32)

#define FP_OPTION 0

/*
 * In the future, the struct definitions may need to be refined based on the
 * specific IA-32 processor, but for now only the Pentium4 is supported.
 *
 * There exists 8 x 80 bit floating point registers (ST[0] -> ST[7]) and
 * 8 * 128 bit XMM registers (XMM[0] -> XMM[7]). All of these registers are
 * considered volatile across a function invocation.
 */

/* a single x87 FPU register in double extended format (80 bits) */

typedef struct fpReg {
	unsigned char reg[10];
} FP_REG;

/* a single XMM register (128 bits) */

typedef struct xmmReg {
	unsigned char reg[16];
} XMM_REG;

/* the set of volatile floating point registers */

typedef struct fpVolatileRegSet {
	XMM_REG xmmRegs[8]; /* XMM[0] -> XMM[7] */
	FP_REG fpRegs[8];   /* ST[0] -> ST[7] */
} FP_VOLATILE_REG_SET;

/* the set of non-volatile floating point registers */

typedef struct fpNonVolatileRegSet {
	/* this structure has been intentionally left blank */
} FP_NONVOLATILE_REG_SET;

#define SIZEOF_FP_VOLATILE_REG_SET sizeof(FP_VOLATILE_REG_SET)
#define SIZEOF_FP_NONVOLATILE_REG_SET 0


#else /* ! CONFIG_ISA_IA32 */

#error Architecture needs to provide a definition for 'struct fpRegSet' \
and 'struct fpNonVolatileRegSet'
#endif /* CONFIG_ISA_IA32 */

/* the set of ALL floating point registers */

typedef struct fpRegSet {
	FP_VOLATILE_REG_SET fpVolRegSet;
	FP_NONVOLATILE_REG_SET fpNonVolRegSet;
} FP_REG_SET;

#define SIZEOF_FP_REG_SET \
	(SIZEOF_FP_VOLATILE_REG_SET + SIZEOF_FP_NONVOLATILE_REG_SET)

/*
 * The following constants define the initial byte value used by the background
 * task, and the fiber when loading up the floating point registers.
 */

#define MAIN_FLOAT_REG_CHECK_BYTE (unsigned char)0xe5
#define FIBER_FLOAT_REG_CHECK_BYTE (unsigned char)0xf9

void _StoreNonVolatileFloatRegisters(FP_NONVOLATILE_REG_SET *pToBuffer);

extern int fpu_sharing_error;

#endif /* _FLOATRCONTEXT_H */