c-r4k.c

Linux Kernel 2.6.9 for OMAP1710

			flush_dcache_line(a);	/* Hit_Writeback_Inv_D */
			if (a == end)
				break;
			a += dc_lsize;
		}
	}

	bc_inv(addr, size);
}
#endif /* CONFIG_DMA_NONCOHERENT */

/*
 * While we're protected against bad userland addresses we don't care
 * very much about what happens in that case.  Usually a segmentation
 * fault will dump the process later on anyway ...
 */
static void r4k_flush_cache_sigtramp(unsigned long addr)
{
	unsigned long ic_lsize = current_cpu_data.icache.linesz;
	unsigned long dc_lsize = current_cpu_data.dcache.linesz;

	R4600_HIT_CACHEOP_WAR_IMPL;
	protected_writeback_dcache_line(addr & ~(dc_lsize - 1));
	protected_flush_icache_line(addr & ~(ic_lsize - 1));
	if (MIPS4K_ICACHE_REFILL_WAR) {
		__asm__ __volatile__ (
			".set push\n\t"
			".set noat\n\t"
			".set mips3\n\t"
#if CONFIG_MIPS32
			"la	$at,1f\n\t"
#endif
#if CONFIG_MIPS64
			"dla	$at,1f\n\t"
#endif
			"cache	%0,($at)\n\t"
			"nop; nop; nop\n"
			"1:\n\t"
			".set pop"
			:
			: "i" (Hit_Invalidate_I));
	}
	if (MIPS_CACHE_SYNC_WAR)
		__asm__ __volatile__ ("sync");
}

static void r4k_flush_icache_all(void)
{
	if (cpu_has_vtag_icache)
		r4k_blast_icache();
}

static inline void rm7k_erratum31(void)
{
	const unsigned long ic_lsize = 32;
	unsigned long addr;

	/* RM7000 erratum #31. The icache is screwed at startup. */
	write_c0_taglo(0);
	write_c0_taghi(0);

	for (addr = INDEX_BASE; addr <= INDEX_BASE + 4096; addr += ic_lsize) {
		__asm__ __volatile__ (
			".set noreorder\n\t"
			".set mips3\n\t"
			"cache\t%1, 0(%0)\n\t"
			"cache\t%1, 0x1000(%0)\n\t"
			"cache\t%1, 0x2000(%0)\n\t"
			"cache\t%1, 0x3000(%0)\n\t"
			"cache\t%2, 0(%0)\n\t"
			"cache\t%2, 0x1000(%0)\n\t"
			"cache\t%2, 0x2000(%0)\n\t"
			"cache\t%2, 0x3000(%0)\n\t"
			"cache\t%1, 0(%0)\n\t"
			"cache\t%1, 0x1000(%0)\n\t"
			"cache\t%1, 0x2000(%0)\n\t"
			"cache\t%1, 0x3000(%0)\n\t"
			".set\tmips0\n\t"
			".set\treorder\n\t"
			:
			: "r" (addr), "i" (Index_Store_Tag_I), "i" (Fill));
	}
}

static char *way_string[] = { NULL, "direct mapped", "2-way", "3-way", "4-way",
	"5-way", "6-way", "7-way", "8-way"
};

static void __init probe_pcache(void)
{
	struct cpuinfo_mips *c = &current_cpu_data;
	unsigned int config = read_c0_config();
	unsigned int prid = read_c0_prid();
	unsigned long config1;
	unsigned int lsize;

	switch (c->cputype) {
	case CPU_R4600:			/* QED style two way caches? */
	case CPU_R4700:
	case CPU_R5000:
	case CPU_NEVADA:
		icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
		c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
		c->icache.ways = 2;
		c->icache.waybit = ffs(icache_size/2) - 1;

		dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
		c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
		c->dcache.ways = 2;
		c->dcache.waybit= ffs(dcache_size/2) - 1;

		c->options |= MIPS_CPU_CACHE_CDEX_P;
		break;

	case CPU_R5432:
	case CPU_R5500:
		icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
		c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
		c->icache.ways = 2;
		c->icache.waybit= 0;

		dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
		c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
		c->dcache.ways = 2;
		c->dcache.waybit = 0;

		c->options |= MIPS_CPU_CACHE_CDEX_P;
		break;

	case CPU_TX49XX:
		icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
		c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
		c->icache.ways = 4;
		c->icache.waybit= 0;

		dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
		c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
		c->dcache.ways = 4;
		c->dcache.waybit = 0;

		c->options |= MIPS_CPU_CACHE_CDEX_P;
		break;

	case CPU_R4000PC:
	case CPU_R4000SC:
	case CPU_R4000MC:
	case CPU_R4400PC:
	case CPU_R4400SC:
	case CPU_R4400MC:
	case CPU_R4300:
		icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
		c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
		c->icache.ways = 1;
		c->icache.waybit = 0; 	/* doesn't matter */

		dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
		c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
		c->dcache.ways = 1;
		c->dcache.waybit = 0;	/* does not matter */

		c->options |= MIPS_CPU_CACHE_CDEX_P;
		break;

	case CPU_R10000:
	case CPU_R12000:
		icache_size = 1 << (12 + ((config & R10K_CONF_IC) >> 29));
		c->icache.linesz = 64;
		c->icache.ways = 2;
		c->icache.waybit = 0;

		dcache_size = 1 << (12 + ((config & R10K_CONF_DC) >> 26));
		c->dcache.linesz = 32;
		c->dcache.ways = 2;
		c->dcache.waybit = 0;

		c->options |= MIPS_CPU_PREFETCH;
		break;

	case CPU_VR4133:
		write_c0_config(config & ~CONF_EB);
	case CPU_VR4131:
		/* Workaround for cache instruction bug of VR4131 */
		if (c->processor_id == 0x0c80U || c->processor_id == 0x0c81U ||
		    c->processor_id == 0x0c82U) {
			config &= ~0x00000030U;
			config |= 0x00410000U;
			write_c0_config(config);
		}
		icache_size = 1 << (10 + ((config & CONF_IC) >> 9));
		c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
		c->icache.ways = 2;
		c->icache.waybit = ffs(icache_size/2) - 1;

		dcache_size = 1 << (10 + ((config & CONF_DC) >> 6));
		c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
		c->dcache.ways = 2;
		c->dcache.waybit = ffs(dcache_size/2) - 1;

		c->options |= MIPS_CPU_CACHE_CDEX_P;
		break;

	case CPU_VR41XX:
	case CPU_VR4111:
	case CPU_VR4121:
	case CPU_VR4122:
	case CPU_VR4181:
	case CPU_VR4181A:
		icache_size = 1 << (10 + ((config & CONF_IC) >> 9));
		c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
		c->icache.ways = 1;
		c->icache.waybit = 0; 	/* doesn't matter */

		dcache_size = 1 << (10 + ((config & CONF_DC) >> 6));
		c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
		c->dcache.ways = 1;
		c->dcache.waybit = 0;	/* does not matter */

		c->options |= MIPS_CPU_CACHE_CDEX_P;
		break;

	case CPU_RM7000:
		rm7k_erratum31();

	case CPU_RM9000:
		icache_size = 1 << (12 + ((config & CONF_IC) >> 9));
		c->icache.linesz = 16 << ((config & CONF_IB) >> 5);
		c->icache.ways = 4;
		c->icache.waybit = ffs(icache_size / c->icache.ways) - 1;

		dcache_size = 1 << (12 + ((config & CONF_DC) >> 6));
		c->dcache.linesz = 16 << ((config & CONF_DB) >> 4);
		c->dcache.ways = 4;
		c->dcache.waybit = ffs(dcache_size / c->dcache.ways) - 1;

#if !defined(CONFIG_SMP) || !defined(RM9000_CDEX_SMP_WAR)
		c->options |= MIPS_CPU_CACHE_CDEX_P;
#endif
		c->options |= MIPS_CPU_PREFETCH;
		break;

	default:
		if (!(config & MIPS_CONF_M))
			panic("Don't know how to probe P-caches on this cpu.");

		/*
		 * So we seem to be a MIPS32 or MIPS64 CPU
		 * So let's probe the I-cache ...
		 */
		config1 = read_c0_config1();

		if ((lsize = ((config1 >> 19) & 7)))
			c->icache.linesz = 2 << lsize;
		else
			c->icache.linesz = lsize;
		c->icache.sets = 64 << ((config1 >> 22) & 7);
		c->icache.ways = 1 + ((config1 >> 16) & 7);

		icache_size = c->icache.sets *
		              c->icache.ways *
		              c->icache.linesz;
		c->icache.waybit = ffs(icache_size/c->icache.ways) - 1;

		if (config & 0x8)		/* VI bit */
			c->icache.flags |= MIPS_CACHE_VTAG;

		/*
		 * Now probe the MIPS32 / MIPS64 data cache.
		 */
		c->dcache.flags = 0;

		if ((lsize = ((config1 >> 10) & 7)))
			c->dcache.linesz = 2 << lsize;
		else
			c->dcache.linesz= lsize;
		c->dcache.sets = 64 << ((config1 >> 13) & 7);
		c->dcache.ways = 1 + ((config1 >> 7) & 7);

		dcache_size = c->dcache.sets *
		              c->dcache.ways *
		              c->dcache.linesz;
		c->dcache.waybit = ffs(dcache_size/c->dcache.ways) - 1;

		c->options |= MIPS_CPU_PREFETCH;
		break;
	}

	/*
	 * Processor configuration sanity check for the R4000SC erratum
	 * #5.  With page sizes larger than 32kB there is no possibility
	 * to get a VCE exception anymore so we don't care about this
	 * misconfiguration.  The case is rather theoretical anyway;
	 * presumably no vendor is shipping his hardware in the "bad"
	 * configuration.
	 */
	if ((prid & 0xff00) == PRID_IMP_R4000 && (prid & 0xff) < 0x40 &&
	    !(config & CONF_SC) && c->icache.linesz != 16 &&
	    PAGE_SIZE <= 0x8000)
		panic("Improper R4000SC processor configuration detected");

	/* compute a couple of other cache variables */
	c->icache.waysize = icache_size / c->icache.ways;
	c->dcache.waysize = dcache_size / c->dcache.ways;

	c->icache.sets = icache_size / (c->icache.linesz * c->icache.ways);
	c->dcache.sets = dcache_size / (c->dcache.linesz * c->dcache.ways);

	/*
	 * R10000 and R12000 P-caches are odd in a positive way.  They're 32kB
	 * 2-way virtually indexed so normally would suffer from aliases.  So
	 * normally they'd suffer from aliases but magic in the hardware deals
	 * with that for us so we don't need to take care ourselves.
	 */
	if (c->cputype != CPU_R10000 && c->cputype != CPU_R12000)
		if (c->dcache.waysize > PAGE_SIZE)
		        c->dcache.flags |= MIPS_CACHE_ALIASES;

	switch (c->cputype) {
	case CPU_20KC:
		/*
		 * Some older 20Kc chips doesn't have the 'VI' bit in
		 * the config register.
		 */
		c->icache.flags |= MIPS_CACHE_VTAG;
		break;

	case CPU_AU1500:
		c->icache.flags |= MIPS_CACHE_IC_F_DC;
		break;
	}

	printk("Primary instruction cache %ldkB, %s, %s, linesize %d bytes.\n",
	       icache_size >> 10,
	       cpu_has_vtag_icache ? "virtually tagged" : "physically tagged",
	       way_string[c->icache.ways], c->icache.linesz);

	printk("Primary data cache %ldkB %s, linesize %d bytes.\n",
	       dcache_size >> 10, way_string[c->dcache.ways], c->dcache.linesz);
}

/*
 * If you even _breathe_ on this function, look at the gcc output and make sure
 * it does not pop things on and off the stack for the cache sizing loop that
 * executes in KSEG1 space or else you will crash and burn badly.  You have
 * been warned.
 */
static int __init probe_scache(void)
{
	extern unsigned long stext;
	unsigned long flags, addr, begin, end, pow2;
	unsigned int config = read_c0_config();
	struct cpuinfo_mips *c = &current_cpu_data;
	int tmp;

	if (config & CONF_SC)
		return 0;

	begin = (unsigned long) &stext;
	begin &= ~((4 * 1024 * 1024) - 1);
	end = begin + (4 * 1024 * 1024);

	/*
	 * This is such a bitch, you'd think they would make it easy to do
	 * this.  Away you daemons of stupidity!
	 */
	local_irq_save(flags);

	/* Fill each size-multiple cache line with a valid tag. */
	pow2 = (64 * 1024);
	for (addr = begin; addr < end; addr = (begin + pow2)) {
		unsigned long *p = (unsigned long *) addr;
		__asm__ __volatile__("nop" : : "r" (*p)); /* whee... */
		pow2 <<= 1;
	}

	/* Load first line with zero (therefore invalid) tag. */
	write_c0_taglo(0);
	write_c0_taghi(0);
	__asm__ __volatile__("nop; nop; nop; nop;"); /* avoid the hazard */
	cache_op(Index_Store_Tag_I, begin);
	cache_op(Index_Store_Tag_D, begin);
	cache_op(Index_Store_Tag_SD, begin);

	/* Now search for the wrap around point. */
	pow2 = (128 * 1024);
	tmp = 0;
	for (addr = begin + (128 * 1024); addr < end; addr = begin + pow2) {
		cache_op(Index_Load_Tag_SD, addr);
		__asm__ __volatile__("nop; nop; nop; nop;"); /* hazard... */
		if (!read_c0_taglo())
			break;
		pow2 <<= 1;
	}
	local_irq_restore(flags);
	addr -= begin;

	scache_size = addr;
	c->scache.linesz = 16 << ((config & R4K_CONF_SB) >> 22);
	c->scache.ways = 1;
	c->dcache.waybit = 0;		/* does not matter */

	return 1;
}

typedef int (*probe_func_t)(unsigned long);
extern int r5k_sc_init(void);
extern int rm7k_sc_init(void);

static void __init setup_scache(void)
{
	struct cpuinfo_mips *c = &current_cpu_data;
	unsigned int config = read_c0_config();
	probe_func_t probe_scache_kseg1;
	int sc_present = 0;

	/*
	 * Do the probing thing on R4000SC and R4400SC processors.  Other
	 * processors don't have a S-cache that would be relevant to the
	 * Linux memory managment.
	 */
	switch (c->cputype) {
	case CPU_R4000SC:
	case CPU_R4000MC:
	case CPU_R4400SC:
	case CPU_R4400MC:
		probe_scache_kseg1 = (probe_func_t) (KSEG1ADDR(&probe_scache));
		sc_present = probe_scache_kseg1(config);
		if (sc_present)
			c->options |= MIPS_CPU_CACHE_CDEX_S;
		break;

	case CPU_R10000:
	case CPU_R12000:
		scache_size = 0x80000 << ((config & R10K_CONF_SS) >> 16);
		c->scache.linesz = 64 << ((config >> 13) & 1);
		c->scache.ways = 2;
		c->scache.waybit= 0;
		sc_present = 1;
		break;

	case CPU_R5000:
	case CPU_NEVADA:
#ifdef CONFIG_R5000_CPU_SCACHE
		r5k_sc_init();
#endif
                return;

	case CPU_RM7000:
	case CPU_RM9000:
#ifdef CONFIG_RM7000_CPU_SCACHE
		rm7k_sc_init();
#endif
		return;

	default:
		sc_present = 0;
	}

	if (!sc_present)
		return;

	if ((c->isa_level == MIPS_CPU_ISA_M32 ||
	     c->isa_level == MIPS_CPU_ISA_M64) &&
	    !(c->scache.flags & MIPS_CACHE_NOT_PRESENT))
		panic("Dunno how to handle MIPS32 / MIPS64 second level cache");

	/* compute a couple of other cache variables */
	c->scache.waysize = scache_size / c->scache.ways;

	c->scache.sets = scache_size / (c->scache.linesz * c->scache.ways);

	printk("Unified secondary cache %ldkB %s, linesize %d bytes.\n",
	       scache_size >> 10, way_string[c->scache.ways], c->scache.linesz);

	c->options |= MIPS_CPU_SUBSET_CACHES;
}

static inline void coherency_setup(void)
{
	change_c0_config(CONF_CM_CMASK, CONF_CM_DEFAULT);

	/*
	 * c0_status.cu=0 specifies that updates by the sc instruction use
	 * the coherency mode specified by the TLB; 1 means cachable
	 * coherent update on write will be used.  Not all processors have
	 * this bit and; some wire it to zero, others like Toshiba had the
	 * silly idea of putting something else there ...
	 */
	switch (current_cpu_data.cputype) {
	case CPU_R4000PC:
	case CPU_R4000SC:
	case CPU_R4000MC:
	case CPU_R4400PC:
	case CPU_R4400SC:
	case CPU_R4400MC:
		clear_c0_config(CONF_CU);
		break;
	}
}

void __init ld_mmu_r4xx0(void)
{
	extern void build_clear_page(void);
	extern void build_copy_page(void);
	extern char except_vec2_generic;
	struct cpuinfo_mips *c = &current_cpu_data;

	/* Default cache error handler for R4000 and R5000 family */
	memcpy((void *)(CAC_BASE   + 0x100), &except_vec2_generic, 0x80);
	memcpy((void *)(UNCAC_BASE + 0x100), &except_vec2_generic, 0x80);

	probe_pcache();
	setup_scache();

	if (c->dcache.sets * c->dcache.ways > PAGE_SIZE)
		c->dcache.flags |= MIPS_CACHE_ALIASES;

	r4k_blast_dcache_page_setup();
	r4k_blast_dcache_page_indexed_setup();
	r4k_blast_dcache_setup();
	r4k_blast_icache_page_setup();
	r4k_blast_icache_page_indexed_setup();
	r4k_blast_icache_setup();
	r4k_blast_scache_page_setup();
	r4k_blast_scache_setup();

	/*
	 * Some MIPS32 and MIPS64 processors have physically indexed caches.
	 * This code supports virtually indexed processors and will be
	 * unnecessarily inefficient on physically indexed processors.
	 */
	shm_align_mask = max_t( unsigned long,
				c->dcache.sets * c->dcache.linesz - 1,
				PAGE_SIZE - 1);

	flush_cache_all		= r4k_flush_cache_all;
	__flush_cache_all	= r4k___flush_cache_all;
	flush_cache_mm		= r4k_flush_cache_mm;
	flush_cache_page	= r4k_flush_cache_page;
	flush_icache_page	= r4k_flush_icache_page;
	flush_cache_range	= r4k_flush_cache_range;

	flush_cache_sigtramp	= r4k_flush_cache_sigtramp;
	flush_icache_all	= r4k_flush_icache_all;
	flush_data_cache_page	= r4k_flush_data_cache_page;
	flush_icache_range	= r4k_flush_icache_range;

#ifdef CONFIG_DMA_NONCOHERENT
	_dma_cache_wback_inv	= r4k_dma_cache_wback_inv;
	_dma_cache_wback	= r4k_dma_cache_wback_inv;
	_dma_cache_inv		= r4k_dma_cache_inv;
#endif

	__flush_cache_all();
	coherency_setup();

	build_clear_page();
	build_copy_page();
}