cpu-probe.c

来自「linux-2.4.29操作系统的源码」· C语言 代码 · 共 891 行 · 第 1/2 页

static inline unsigned long cpu_get_fpu_id(void)
{
	unsigned long tmp, fpu_id;

	tmp = read_c0_status();
	__enable_fpu();
	fpu_id = read_32bit_cp1_register(CP1_REVISION);
	write_c0_status(tmp);
	return fpu_id;
}

/*
 * Check the CPU has an FPU the official way.
 */
static inline int __cpu_has_fpu(void)
{
	return ((cpu_get_fpu_id() & 0xff00) != FPIR_IMP_NONE);
}

#define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4KTLB \
		| MIPS_CPU_COUNTER)

static inline void cpu_probe_legacy(struct cpuinfo_mips *c)
{
	switch (c->processor_id & 0xff00) {
	case PRID_IMP_R2000:
		c->cputype = CPU_R2000;
		c->isa_level = MIPS_CPU_ISA_I;
		c->options = MIPS_CPU_TLB | MIPS_CPU_NOFPUEX;
		if (__cpu_has_fpu())
			c->options |= MIPS_CPU_FPU;
		c->tlbsize = 64;
		break;
	case PRID_IMP_R3000:
		if ((c->processor_id & 0xff) == PRID_REV_R3000A)
			if (cpu_has_confreg())
				c->cputype = CPU_R3081E;
			else
				c->cputype = CPU_R3000A;
		else
			c->cputype = CPU_R3000;
		c->isa_level = MIPS_CPU_ISA_I;
		c->options = MIPS_CPU_TLB | MIPS_CPU_NOFPUEX; 
		if (__cpu_has_fpu())
			c->options |= MIPS_CPU_FPU;
		c->tlbsize = 64;
		break;
	case PRID_IMP_R4000:
		if (read_c0_config() & CONF_SC) {
			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
				c->cputype = CPU_R4400PC;
			else
				c->cputype = CPU_R4000PC;
		} else {
			if ((c->processor_id & 0xff) >= PRID_REV_R4400)
				c->cputype = CPU_R4400SC;
			else
				c->cputype = CPU_R4000SC;
		}

		c->isa_level = MIPS_CPU_ISA_III;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
		             MIPS_CPU_WATCH | MIPS_CPU_VCE |
		             MIPS_CPU_LLSC;
		c->tlbsize = 48;
		break;
	case PRID_IMP_VR41XX:
		switch (c->processor_id & 0xf0) {
#ifndef CONFIG_VR4181
		case PRID_REV_VR4111:
			c->cputype = CPU_VR4111;
			break;
#else
		case PRID_REV_VR4181:
			c->cputype = CPU_VR4181;
			break;
#endif
		case PRID_REV_VR4121:
			c->cputype = CPU_VR4121;
			break;
		case PRID_REV_VR4122:
			if ((c->processor_id & 0xf) < 0x3)
				c->cputype = CPU_VR4122;
			else
				c->cputype = CPU_VR4181A;
			break;
		case PRID_REV_VR4130:
			if ((c->processor_id & 0xf) < 0x4)
				c->cputype = CPU_VR4131;
			else
				c->cputype = CPU_VR4133;
			break;
		default:
			printk(KERN_INFO "Unexpected CPU of NEC VR4100 series\n");
			c->cputype = CPU_VR41XX;
			break;
		}
		c->isa_level = MIPS_CPU_ISA_III;
		c->options = R4K_OPTS;
		c->tlbsize = 32;
		break;
	case PRID_IMP_R4300:
		c->cputype = CPU_R4300;
		c->isa_level = MIPS_CPU_ISA_III;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
		             MIPS_CPU_LLSC;
		c->tlbsize = 32;
		break;
	case PRID_IMP_R4600:
		c->cputype = CPU_R4600;
		c->isa_level = MIPS_CPU_ISA_III;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
		c->tlbsize = 48;
		break;
	#if 0
 	case PRID_IMP_R4650:
		/*
		 * This processor doesn't have an MMU, so it's not
		 * "real easy" to run Linux on it. It is left purely
		 * for documentation.  Commented out because it shares
		 * it's c0_prid id number with the TX3900.
		 */
 		c->cputype = CPU_R4650;
	 	c->isa_level = MIPS_CPU_ISA_III;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC;
	        c->tlbsize = 48;
		break;
	#endif
	case PRID_IMP_TX39:
		c->isa_level = MIPS_CPU_ISA_I;
		c->options = MIPS_CPU_TLB;

		if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) {
			c->cputype = CPU_TX3927;
			c->tlbsize = 64;
		} else {
			switch (c->processor_id & 0xff) {
			case PRID_REV_TX3912:
				c->cputype = CPU_TX3912;
				c->tlbsize = 32;
				break;
			case PRID_REV_TX3922:
				c->cputype = CPU_TX3922;
				c->tlbsize = 64;
				break;
			default:
				c->cputype = CPU_UNKNOWN;
				break;
			}
		}
		break;
	case PRID_IMP_R4700:
		c->cputype = CPU_R4700;
		c->isa_level = MIPS_CPU_ISA_III;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
		             MIPS_CPU_LLSC;
		c->tlbsize = 48;
		break;
	case PRID_IMP_TX49:
		c->cputype = CPU_TX49XX;
		c->isa_level = MIPS_CPU_ISA_III;
		c->options = R4K_OPTS | MIPS_CPU_LLSC;
		if (!(c->processor_id & 0x08))
			c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
		c->tlbsize = 48;
		break;
	case PRID_IMP_R5000:
		c->cputype = CPU_R5000;
		c->isa_level = MIPS_CPU_ISA_IV;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
		             MIPS_CPU_LLSC;
		c->tlbsize = 48;
		break;
	case PRID_IMP_R5432:
		c->cputype = CPU_R5432;
		c->isa_level = MIPS_CPU_ISA_IV;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
		c->tlbsize = 48;
		break;
	case PRID_IMP_R5500:
		c->cputype = CPU_R5500;
		c->isa_level = MIPS_CPU_ISA_IV;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
		c->tlbsize = 48;
		break;
	case PRID_IMP_NEVADA:
		c->cputype = CPU_NEVADA;
		c->isa_level = MIPS_CPU_ISA_IV;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
		c->tlbsize = 48;
		break;
	case PRID_IMP_R6000:
		c->cputype = CPU_R6000;
		c->isa_level = MIPS_CPU_ISA_II;
		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
		             MIPS_CPU_LLSC;
		c->tlbsize = 32;
		break;
	case PRID_IMP_R6000A:
		c->cputype = CPU_R6000A;
		c->isa_level = MIPS_CPU_ISA_II;
		c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
		             MIPS_CPU_LLSC;
		c->tlbsize = 32;
		break;
	case PRID_IMP_RM7000:
		c->cputype = CPU_RM7000;
		c->isa_level = MIPS_CPU_ISA_IV;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
		             MIPS_CPU_LLSC;
		/*
		 * Undocumented RM7000:  Bit 29 in the info register of
		 * the RM7000 v2.0 indicates if the TLB has 48 or 64
		 * entries.
		 *
		 * 29      1 =>    64 entry JTLB
		 *         0 =>    48 entry JTLB
		 */
		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
		break;
	case PRID_IMP_RM9000:
		c->cputype = CPU_RM9000;
		c->isa_level = MIPS_CPU_ISA_IV;
		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
		             MIPS_CPU_LLSC;
		/*
		 * Bit 29 in the info register of the RM9000
		 * indicates if the TLB has 48 or 64 entries.
		 *
		 * 29      1 =>    64 entry JTLB
		 *         0 =>    48 entry JTLB
		 */
		c->tlbsize = (read_c0_info() & (1 << 29)) ? 64 : 48;
		break;
	case PRID_IMP_R8000:
		c->cputype = CPU_R8000;
		c->isa_level = MIPS_CPU_ISA_IV;
		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
		             MIPS_CPU_LLSC;
		c->tlbsize = 384;      /* has weird TLB: 3-way x 128 */
		break;
	case PRID_IMP_R10000:
		c->cputype = CPU_R10000;
		c->isa_level = MIPS_CPU_ISA_IV;
		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
		             MIPS_CPU_LLSC;
		c->tlbsize = 64;
		break;
	case PRID_IMP_R12000:
		c->cputype = CPU_R12000;
		c->isa_level = MIPS_CPU_ISA_IV;
		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
		             MIPS_CPU_FPU | MIPS_CPU_32FPR |
			     MIPS_CPU_COUNTER | MIPS_CPU_WATCH |
		             MIPS_CPU_LLSC;
		c->tlbsize = 64;
		break;
	default:
		c->cputype = CPU_UNKNOWN;
		break;
	}
}

static inline void decode_config1(struct cpuinfo_mips *c)
{
	unsigned long config0 = read_c0_config();
	unsigned long config1;

	if ((config0 & (1 << 31)) == 0)
		return;			/* actually wort a panic() */

	/* MIPS32 or MIPS64 compliant CPU. Read Config 1 register. */
	c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
		MIPS_CPU_4KTLB | MIPS_CPU_COUNTER | MIPS_CPU_DIVEC |
		MIPS_CPU_LLSC;
	config1 = read_c0_config1();
	if (config1 & (1 << 3))
		c->options |= MIPS_CPU_WATCH;
	if (config1 & (1 << 2))
		c->options |= MIPS_CPU_MIPS16;
	if (config1 & (1 << 1))
		c->options |= MIPS_CPU_EJTAG;
	if (config1 & 1) {
		c->options |= MIPS_CPU_FPU;
		c->options |= MIPS_CPU_32FPR;
	}
	c->scache.flags = MIPS_CACHE_NOT_PRESENT;

	c->tlbsize = ((config1 >> 25) & 0x3f) + 1;
}

static inline void cpu_probe_mips(struct cpuinfo_mips *c)
{
	decode_config1(c);
	switch (c->processor_id & 0xff00) {
	case PRID_IMP_4KC:
		c->cputype = CPU_4KC;
		c->isa_level = MIPS_CPU_ISA_M32;
		break;
	case PRID_IMP_4KEC:
		c->cputype = CPU_4KEC;
		c->isa_level = MIPS_CPU_ISA_M32;
		break;
	case PRID_IMP_4KSC:
		c->cputype = CPU_4KSC;
		c->isa_level = MIPS_CPU_ISA_M32;
		break;
	case PRID_IMP_5KC:
		c->cputype = CPU_5KC;
		c->isa_level = MIPS_CPU_ISA_M64;
		break;
	case PRID_IMP_20KC:
		c->cputype = CPU_20KC;
		c->isa_level = MIPS_CPU_ISA_M64;
		break;
	case PRID_IMP_24K:
		c->cputype = CPU_24K;
		c->isa_level = MIPS_CPU_ISA_M32;
		break;
	case PRID_IMP_25KF:
		c->cputype = CPU_25KF;
		c->isa_level = MIPS_CPU_ISA_M64;
		/* Probe for L2 cache */
		c->scache.flags &= ~MIPS_CACHE_NOT_PRESENT;
		break;
	default:
		c->cputype = CPU_UNKNOWN;
		break;
	}
}

static inline void cpu_probe_alchemy(struct cpuinfo_mips *c)
{
	decode_config1(c);
	switch (c->processor_id & 0xff00) {
	case PRID_IMP_AU1_REV1:
	case PRID_IMP_AU1_REV2:
		switch ((c->processor_id >> 24) & 0xff) {
		case 0:
 			c->cputype = CPU_AU1000;
			break;
		case 1:
			c->cputype = CPU_AU1500;
			break;
		case 2:
			c->cputype = CPU_AU1100;
			break;
		default:
			panic("Unknown Au Core!");
			break;
		}
		c->isa_level = MIPS_CPU_ISA_M32;
		break;
	}
}

static inline void cpu_probe_sibyte(struct cpuinfo_mips *c)
{
	decode_config1(c);
	switch (c->processor_id & 0xff00) {
	case PRID_IMP_SB1:
		c->cputype = CPU_SB1;
		c->isa_level = MIPS_CPU_ISA_M64;
		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
		             MIPS_CPU_COUNTER | MIPS_CPU_DIVEC |
		             MIPS_CPU_MCHECK | MIPS_CPU_EJTAG |
		             MIPS_CPU_WATCH | MIPS_CPU_LLSC;
#ifndef CONFIG_SB1_PASS_1_WORKAROUNDS
		/* FPU in pass1 is known to have issues. */
		c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR;
#endif
		break;
	default:
		c->cputype = CPU_UNKNOWN;
		break;
	}
}

static inline void cpu_probe_sandcraft(struct cpuinfo_mips *c)
{
	decode_config1(c);
	switch (c->processor_id & 0xff00) {
	case PRID_IMP_SR71000:
		c->cputype = CPU_SR71000;
		c->isa_level = MIPS_CPU_ISA_M64;
		c->options = MIPS_CPU_TLB | MIPS_CPU_4KEX |
		             MIPS_CPU_4KTLB | MIPS_CPU_FPU |
		             MIPS_CPU_COUNTER | MIPS_CPU_MCHECK;
		c->scache.ways = 8;
		c->tlbsize = 64;
		break;
	default:
		c->cputype = CPU_UNKNOWN;
		break;
	}
}

__init void cpu_probe(void)
{
	struct cpuinfo_mips *c = &current_cpu_data;

	c->processor_id	= PRID_IMP_UNKNOWN;
	c->fpu_id	= FPIR_IMP_NONE;
	c->cputype	= CPU_UNKNOWN;

	c->processor_id = read_c0_prid();
	switch (c->processor_id & 0xff0000) {
	case PRID_COMP_LEGACY:
		cpu_probe_legacy(c);
		break;
	case PRID_COMP_MIPS:
		cpu_probe_mips(c);
		break;
	case PRID_COMP_ALCHEMY:
		cpu_probe_alchemy(c);
		break;
	case PRID_COMP_SIBYTE:
		cpu_probe_sibyte(c);
		break;

	case PRID_COMP_SANDCRAFT:
		cpu_probe_sandcraft(c);
		break;
	default:
		c->cputype = CPU_UNKNOWN;
	}
	if (c->options & MIPS_CPU_FPU)
		c->fpu_id = cpu_get_fpu_id();
}

__init void cpu_report(void)
{
	struct cpuinfo_mips *c = &current_cpu_data;

	printk("CPU revision is: %08x\n", c->processor_id);
	if (c->options & MIPS_CPU_FPU)
		printk("FPU revision is: %08x\n", c->fpu_id);
}