minix/kernel/arch/earm/include/cpufunc.h

#ifndef _ARM_CPUFUNC_H
#define _ARM_CPUFUNC_H

#if 0
/* check interrupt state */
static inline void check_int(unsigned int state, int line)
{
	unsigned int cpsr = 0;

	asm volatile("mrs %0, cpsr" : "=r" (cpsr));

	if ((cpsr & PSR_F) != (state & PSR_F))
	    printf("%d: FIQs are unexpectedly %s\n", line, (cpsr & PSR_F) ? "MASKED" : "UNMASKED");

	if ((cpsr & PSR_I) != (state & PSR_I))
	    printf("%d: IRQs are unexpectedly %s\n", line, (cpsr & PSR_I) ? "MASKED" : "UNMASKED");

}
#endif

/* Data memory barrier */
static inline void dmb(void)
{
	asm volatile("dmb" : : : "memory");
}

/* Data synchronization barrier */
static inline void dsb(void)
{
	asm volatile("dsb" : : : "memory");
}

/* Instruction synchronization barrier */
static inline void isb(void)
{
	asm volatile("isb" : : : "memory");
}

static inline void barrier(void)
{
	dsb();
	isb();
}

static inline void refresh_tlb(void)
{
	dsb();

	/* Invalidate entire unified TLB */
	asm volatile("mcr p15, 0, %[zero], c8, c7, 0 @ TLBIALL\n\t" : : [zero] "r" (0));

#if 0
	/* Invalidate entire data TLB */
	asm volatile("mcr p15, 0, %[zero], c8, c6, 0" : : [zero] "r" (0));

	/* Invalidate entire instruction TLB */
	asm volatile("mcr p15, 0, %[zero], c8, c5, 0" : : [zero] "r" (0));
#endif

#if 0
	/*
	 * Invalidate all instruction caches to PoU.
	 * Also flushes branch target cache.
	 */
	asm volatile("mcr p15, 0, %[zero], c7, c5, 0" : : [zero] "r" (0));

	/* Invalidate entire branch predictor array */
	asm volatile("mcr p15, 0, %[zero], c7, c5, 6" : : [zero] "r" (0)); /* flush BTB */
#endif

	dsb();
	isb();
}


/* Read System Control Register */
static inline u32_t read_sctlr()
{
	u32_t ctl;

	asm volatile("mrc p15, 0, %[ctl], c1, c0, 0 @ Read SCTLR\n\t"
			: [ctl] "=r" (ctl));

	return ctl;
}

/* Write System Control Register */
static inline void write_sctlr(u32_t ctl)
{
	asm volatile("mcr p15, 0, %[ctl], c1, c0, 0 @ Write SCTLR\n\t"
			: : [ctl] "r" (ctl));
	isb();
}

/* Read Translation Table Base Register 0 */
static inline u32_t read_ttbr0()
{
	u32_t bar;

	asm volatile("mrc p15, 0, %[bar], c2, c0, 0 @ Read TTBR0\n\t"
			: [bar] "=r" (bar));

	return bar;
}

/* Write Translation Table Base Register 0 */
static inline void write_ttbr0(u32_t bar)
{
	barrier();

	asm volatile("mcr p15, 0, %[bar], c2, c0, 0 @ Write TTBR0\n\t"
			: : [bar] "r" (bar));

	refresh_tlb();
}

/* Reload Translation Table Base Register 0 */
static inline void reload_ttbr0(void)
{
	reg_t ttbr = read_ttbr0();

	write_ttbr0(ttbr);
}

/* Read Translation Table Base Register 1 */
static inline u32_t read_ttbr1()
{
	u32_t bar;

	asm volatile("mrc p15, 0, %[bar], c2, c0, 1 @ Read TTBR1\n\t"
			: [bar] "=r" (bar));

	return bar;
}

/* Write Translation Table Base Register 1 */
static inline void write_ttbr1(u32_t bar)
{
	barrier();

	asm volatile("mcr p15, 0, %[bar], c2, c0, 1 @ Write TTBR1\n\t"
			: : [bar] "r" (bar));

	refresh_tlb();
}

/* Reload Translation Table Base Register 1 */
static inline void reload_ttbr1(void)
{
	reg_t ttbr = read_ttbr1();

	write_ttbr1(ttbr);
}

/* Read Translation Table Base Control Register */
static inline u32_t read_ttbcr()
{
	u32_t bcr;

	asm volatile("mrc p15, 0, %[bcr], c2, c0, 2 @ Read TTBCR\n\t"
			: [bcr] "=r" (bcr));

	return bcr;
}

/* Write Translation Table Base Control Register */
static inline void write_ttbcr(u32_t bcr)
{
	asm volatile("mcr p15, 0, %[bcr], c2, c0, 2 @ Write TTBCR\n\t"
			: : [bcr] "r" (bcr));

	isb();
}

/* Read Domain Access Control Register */
static inline u32_t read_dacr()
{
	u32_t dacr;

	asm volatile("mrc p15, 0, %[dacr], c3, c0, 0 @ Read DACR\n\t"
			: [dacr] "=r" (dacr));

	return dacr;
}

/* Write Domain Access Control Register */
static inline void write_dacr(u32_t dacr)
{
	asm volatile("mcr p15, 0, %[dacr], c3, c0, 0 @ Write DACR\n\t"
			: : [dacr] "r" (dacr));

	isb();
}

/* Read Data Fault Status Register */
static inline u32_t read_dfsr()
{
	u32_t fsr;

	asm volatile("mrc p15, 0, %[fsr], c5, c0, 0 @ Read DFSR\n\t"
			: [fsr] "=r" (fsr));

	return fsr;
}

/* Write Data Fault Status Register */
static inline void write_dfsr(u32_t fsr)
{
	asm volatile("mcr p15, 0, %[fsr], c5, c0, 0 @ Write DFSR\n\t"
			: : [fsr] "r" (fsr));

	isb();
}

/* Read Instruction Fault Status Register */
static inline u32_t read_ifsr()
{
	u32_t fsr;

	asm volatile("mrc p15, 0, %[fsr], c5, c0, 1 @ Read IFSR\n\t"
			: [fsr] "=r" (fsr));

	return fsr;
}

/* Write Instruction Fault Status Register */
static inline void write_ifsr(u32_t fsr)
{
	asm volatile("mcr p15, 0, %[fsr], c5, c0, 1 @ Write IFSR\n\t"
			: : [fsr] "r" (fsr));

	isb();
}

/* Read Data Fault Address Register */
static inline u32_t read_dfar()
{
	u32_t far;

	asm volatile("mrc p15, 0, %[far], c6, c0, 0 @ Read DFAR\n\t"
			: [far] "=r" (far));

	return far;
}

/* Write Data Fault Address Register */
static inline void write_dfar(u32_t far)
{
	asm volatile("mcr p15, 0, %[far], c6, c0, 0 @ Write DFAR\n\t"
			: : [far] "r" (far));

	isb();
}

/* Read Instruction Fault Address Register */
static inline u32_t read_ifar()
{
	u32_t far;

	asm volatile("mrc p15, 0, %[far], c6, c0, 2 @ Read IFAR\n\t"
			: [far] "=r" (far));

	return far;
}

/* Write Instruction Fault Address Register */
static inline void write_ifar(u32_t far)
{
	asm volatile("mcr p15, 0, %[far], c6, c0, 2 @ Write IFAR\n\t"
			: : [far] "r" (far));

	isb();
}

/* Read Vector Base Address Register */
static inline u32_t read_vbar()
{
	u32_t vbar;

	asm volatile("mrc p15, 0, %[vbar], c12, c0, 0 @ Read VBAR\n\t"
			: [vbar] "=r" (vbar));

	return vbar;
}

/* Write Vector Base Address Register */
static inline void write_vbar(u32_t vbar)
{
	asm volatile("mcr p15, 0, %[vbar], c12, c0, 0 @ Write VBAR\n\t"
			: : [vbar] "r" (vbar));

	isb();
}

/* Read the Main ID Register  */
static inline u32_t read_midr()
{
	u32_t id;

	asm volatile("mrc p15, 0, %[id], c0, c0, 0 @ read MIDR\n\t"
			: [id] "=r" (id));

	return id;
}

/* Read Auxiliary Control Register */
static inline u32_t read_actlr()
{
	u32_t ctl;

	asm volatile("mrc p15, 0, %[ctl], c1, c0, 1 @ Read ACTLR\n\t"
			: [ctl] "=r" (ctl));

	return ctl;
}

/* Write Auxiliary Control Register */
static inline void write_actlr(u32_t ctl)
{
	asm volatile("mcr p15, 0, %[ctl], c1, c0, 1 @ Write ACTLR\n\t"
			: : [ctl] "r" (ctl));

	isb();
}

/* Read Current Program Status Register */
static inline u32_t read_cpsr()
{
	u32_t status;

	asm volatile("mrs %[status], cpsr @ read CPSR"
			: [status] "=r" (status));

	return status;
}

/* Write Current Program Status Register */
static inline void write_cpsr(u32_t status)
{
	asm volatile("msr cpsr_c, %[status] @ write CPSR"
			: : [status] "r" (status));
}

#endif /* _ARM_CPUFUNC_H */