c-r4k.c

LINUX 2.6.17.4的源码

	pmdp = pmd_offset(pudp, addr);
	ptep = pte_offset(pmdp, addr);

	/*
	 * If the page isn't marked valid, the page cannot possibly be
	 * in the cache.
	 */
	if (!(pte_val(*ptep) & _PAGE_PRESENT))
		return;

	/*
	 * Doing flushes for another ASID than the current one is
	 * too difficult since stupid R4k caches do a TLB translation
	 * for every cache flush operation.  So we do indexed flushes
	 * in that case, which doesn't overly flush the cache too much.
	 */
	if ((mm == current->active_mm) && (pte_val(*ptep) & _PAGE_VALID)) {
		if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc)) {
			r4k_blast_dcache_page(addr);
			if (exec && !cpu_icache_snoops_remote_store)
				r4k_blast_scache_page(addr);
		}
		if (exec)
			r4k_blast_icache_page(addr);

		return;
	}

	/*
	 * Do indexed flush, too much work to get the (possible) TLB refills
	 * to work correctly.
	 */
	if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc)) {
		r4k_blast_dcache_page_indexed(cpu_has_pindexed_dcache ?
					      paddr : addr);
		if (exec && !cpu_icache_snoops_remote_store) {
			r4k_blast_scache_page_indexed(paddr);
		}
	}
	if (exec) {
		if (cpu_has_vtag_icache) {
			int cpu = smp_processor_id();

			if (cpu_context(cpu, mm) != 0)
				drop_mmu_context(mm, cpu);
		} else
			r4k_blast_icache_page_indexed(addr);
	}
}

static void r4k_flush_cache_page(struct vm_area_struct *vma,
	unsigned long addr, unsigned long pfn)
{
	struct flush_cache_page_args args;

	args.vma = vma;
	args.addr = addr;
	args.pfn = pfn;

	r4k_on_each_cpu(local_r4k_flush_cache_page, &args, 1, 1);
}

static inline void local_r4k_flush_data_cache_page(void * addr)
{
	r4k_blast_dcache_page((unsigned long) addr);
}

static void r4k_flush_data_cache_page(unsigned long addr)
{
	r4k_on_each_cpu(local_r4k_flush_data_cache_page, (void *) addr, 1, 1);
}

struct flush_icache_range_args {
	unsigned long start;
	unsigned long end;
};

static inline void local_r4k_flush_icache_range(void *args)
{
	struct flush_icache_range_args *fir_args = args;
	unsigned long start = fir_args->start;
	unsigned long end = fir_args->end;

	if (!cpu_has_ic_fills_f_dc) {
		if (end - start > dcache_size) {
			r4k_blast_dcache();
		} else {
			R4600_HIT_CACHEOP_WAR_IMPL;
			protected_blast_dcache_range(start, end);
		}

		if (!cpu_icache_snoops_remote_store && scache_size) {
			if (end - start > scache_size)
				r4k_blast_scache();
			else
				protected_blast_scache_range(start, end);
		}
	}

	if (end - start > icache_size)
		r4k_blast_icache();
	else
		protected_blast_icache_range(start, end);
}

static void r4k_flush_icache_range(unsigned long start, unsigned long end)
{
	struct flush_icache_range_args args;

	args.start = start;
	args.end = end;

	r4k_on_each_cpu(local_r4k_flush_icache_range, &args, 1, 1);
	instruction_hazard();
}

/*
 * Ok, this seriously sucks.  We use them to flush a user page but don't
 * know the virtual address, so we have to blast away the whole icache
 * which is significantly more expensive than the real thing.  Otoh we at
 * least know the kernel address of the page so we can flush it
 * selectivly.
 */

struct flush_icache_page_args {
	struct vm_area_struct *vma;
	struct page *page;
};

static inline void local_r4k_flush_icache_page(void *args)
{
	struct flush_icache_page_args *fip_args = args;
	struct vm_area_struct *vma = fip_args->vma;
	struct page *page = fip_args->page;

	/*
	 * Tricky ...  Because we don't know the virtual address we've got the
	 * choice of either invalidating the entire primary and secondary
	 * caches or invalidating the secondary caches also.  With the subset
	 * enforcment on R4000SC, R4400SC, R10000 and R12000 invalidating the
	 * secondary cache will result in any entries in the primary caches
	 * also getting invalidated which hopefully is a bit more economical.
	 */
	if (cpu_has_subset_pcaches) {
		unsigned long addr = (unsigned long) page_address(page);

		r4k_blast_scache_page(addr);
		ClearPageDcacheDirty(page);

		return;
	}

	if (!cpu_has_ic_fills_f_dc) {
		unsigned long addr = (unsigned long) page_address(page);
		r4k_blast_dcache_page(addr);
		if (!cpu_icache_snoops_remote_store)
			r4k_blast_scache_page(addr);
		ClearPageDcacheDirty(page);
	}

	/*
	 * We're not sure of the virtual address(es) involved here, so
	 * we have to flush the entire I-cache.
	 */
	if (cpu_has_vtag_icache) {
		int cpu = smp_processor_id();

		if (cpu_context(cpu, vma->vm_mm) != 0)
			drop_mmu_context(vma->vm_mm, cpu);
	} else
		r4k_blast_icache();
}

static void r4k_flush_icache_page(struct vm_area_struct *vma,
	struct page *page)
{
	struct flush_icache_page_args args;

	/*
	 * If there's no context yet, or the page isn't executable, no I-cache
	 * flush is needed.
	 */
	if (!(vma->vm_flags & VM_EXEC))
		return;

	args.vma = vma;
	args.page = page;

	r4k_on_each_cpu(local_r4k_flush_icache_page, &args, 1, 1);
}


#ifdef CONFIG_DMA_NONCOHERENT

static void r4k_dma_cache_wback_inv(unsigned long addr, unsigned long size)
{
	/* Catch bad driver code */
	BUG_ON(size == 0);

	if (cpu_has_subset_pcaches) {
		if (size >= scache_size)
			r4k_blast_scache();
		else
			blast_scache_range(addr, addr + size);
		return;
	}

	/*
	 * Either no secondary cache or the available caches don't have the
	 * subset property so we have to flush the primary caches
	 * explicitly
	 */
	if (size >= dcache_size) {
		r4k_blast_dcache();
	} else {
		R4600_HIT_CACHEOP_WAR_IMPL;
		blast_dcache_range(addr, addr + size);
	}

	bc_wback_inv(addr, size);
}

static void r4k_dma_cache_inv(unsigned long addr, unsigned long size)
{
	/* Catch bad driver code */
	BUG_ON(size == 0);

	if (cpu_has_subset_pcaches) {
		if (size >= scache_size)
			r4k_blast_scache();
		else
			blast_scache_range(addr, addr + size);
		return;
	}

	if (size >= dcache_size) {
		r4k_blast_dcache();
	} else {
		R4600_HIT_CACHEOP_WAR_IMPL;
		blast_dcache_range(addr, addr + size);
	}

	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 local_r4k_flush_cache_sigtramp(void * arg)
{
	unsigned long ic_lsize = cpu_icache_line_size();
	unsigned long dc_lsize = cpu_dcache_line_size();
	unsigned long sc_lsize = cpu_scache_line_size();
	unsigned long addr = (unsigned long) arg;

	R4600_HIT_CACHEOP_WAR_IMPL;
	protected_writeback_dcache_line(addr & ~(dc_lsize - 1));
	if (!cpu_icache_snoops_remote_store && scache_size)
		protected_writeback_scache_line(addr & ~(sc_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"
#ifdef CONFIG_32BIT
			"la	$at,1f\n\t"
#endif
#ifdef CONFIG_64BIT
			"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_cache_sigtramp(unsigned long addr)
{
	r4k_on_each_cpu(local_r4k_flush_cache_sigtramp, (void *) addr, 1, 1);
}

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 push\n\t"
			".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 pop\n"
			:
			: "r" (addr), "i" (Index_Store_Tag_I), "i" (Fill));
	}
}

static char *way_string[] __initdata = { 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);

		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);

		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;
		c->options |= MIPS_CPU_PREFETCH;
		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:
	case CPU_R14000:
		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);