patch-2.4.7 linux/arch/mips/mm/mips32.c

• Lines: 1079
• Date: Wed Jul 4 11:50:39 2001
• Orig file: v2.4.6/linux/arch/mips/mm/mips32.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.6/linux/arch/mips/mm/mips32.c linux/arch/mips/mm/mips32.c
@@ -0,0 +1,1078 @@
+/*
+ * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
+ *
+ * This program is free software; you can distribute it and/or modify it
+ * under the terms of the GNU General Public License (Version 2) as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * MIPS32 CPU variant specific MMU/Cache routines.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+
+#include <asm/bootinfo.h>
+#include <asm/cpu.h>
+#include <asm/bcache.h>
+#include <asm/io.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/mmu_context.h>
+
+/* CP0 hazard avoidance. */
+#define BARRIER __asm__ __volatile__(".set noreorder\n\t" \
+				     "nop; nop; nop; nop; nop; nop;\n\t" \
+				     ".set reorder\n\t")
+
+/* Primary cache parameters. */
+static int icache_size, dcache_size; /* Size in bytes */
+static int ic_lsize, dc_lsize;       /* LineSize in bytes */
+
+/* Secondary cache (if present) parameters. */
+static unsigned int scache_size, sc_lsize;	/* Again, in bytes */
+
+#include <asm/cacheops.h>
+#include <asm/mips32_cache.h>
+
+#undef DEBUG_CACHE
+
+/*
+ * Dummy cache handling routines for machines without boardcaches
+ */
+static void no_sc_noop(void) {}
+
+static struct bcache_ops no_sc_ops = {
+	(void *)no_sc_noop, (void *)no_sc_noop,
+	(void *)no_sc_noop, (void *)no_sc_noop
+};
+
+struct bcache_ops *bcops = &no_sc_ops;
+
+
+/*
+ * Zero an entire page.
+ */
+
+static void mips32_clear_page_dc(unsigned long page)
+{
+	unsigned long i;
+
+        if (mips_cpu.options & MIPS_CPU_CACHE_CDEX)
+	{
+	        for (i=page; i<page+PAGE_SIZE; i+=dc_lsize)
+		{
+		        __asm__ __volatile__(
+			        ".set\tnoreorder\n\t"
+				".set\tnoat\n\t"
+				".set\tmips3\n\t"
+				"cache\t%2,(%0)\n\t"
+				".set\tmips0\n\t"
+				".set\tat\n\t"
+				".set\treorder"
+				:"=r" (i)
+				:"0" (i),
+				"I" (Create_Dirty_Excl_D));
+		}
+	}
+	for (i=page; i<page+PAGE_SIZE; i+=4)
+	        *(unsigned long *)(i) = 0;
+}
+
+static void mips32_clear_page_sc(unsigned long page)
+{
+	unsigned long i;
+
+        if (mips_cpu.options & MIPS_CPU_CACHE_CDEX)
+	{
+	        for (i=page; i<page+PAGE_SIZE; i+=sc_lsize)
+		{
+		        __asm__ __volatile__(
+				".set\tnoreorder\n\t"
+				".set\tnoat\n\t"
+				".set\tmips3\n\t"
+				"cache\t%2,(%0)\n\t"
+				".set\tmips0\n\t"
+				".set\tat\n\t"
+				".set\treorder"
+				:"=r" (i)
+				:"0" (i),
+				"I" (Create_Dirty_Excl_SD));
+		}
+	}
+	for (i=page; i<page+PAGE_SIZE; i+=4)
+	        *(unsigned long *)(i) = 0;
+}
+
+static void mips32_copy_page_dc(unsigned long to, unsigned long from)
+{
+	unsigned long i;
+
+        if (mips_cpu.options & MIPS_CPU_CACHE_CDEX)
+	{
+	        for (i=to; i<to+PAGE_SIZE; i+=dc_lsize)
+		{
+		        __asm__ __volatile__(
+			        ".set\tnoreorder\n\t"
+				".set\tnoat\n\t"
+				".set\tmips3\n\t"
+				"cache\t%2,(%0)\n\t"
+				".set\tmips0\n\t"
+				".set\tat\n\t"
+				".set\treorder"
+				:"=r" (i)
+				:"0" (i),
+				"I" (Create_Dirty_Excl_D));
+		}
+	}
+	for (i=0; i<PAGE_SIZE; i+=4)
+	        *(unsigned long *)(to+i) = *(unsigned long *)(from+i);
+}
+
+static void mips32_copy_page_sc(unsigned long to, unsigned long from)
+{
+	unsigned long i;
+
+        if (mips_cpu.options & MIPS_CPU_CACHE_CDEX)
+	{
+	        for (i=to; i<to+PAGE_SIZE; i+=sc_lsize)
+		{
+		        __asm__ __volatile__(
+				".set\tnoreorder\n\t"
+				".set\tnoat\n\t"
+				".set\tmips3\n\t"
+				"cache\t%2,(%0)\n\t"
+				".set\tmips0\n\t"
+				".set\tat\n\t"
+				".set\treorder"
+				:"=r" (i)
+				:"0" (i),
+				"I" (Create_Dirty_Excl_SD));
+		}
+	}
+	for (i=0; i<PAGE_SIZE; i+=4)
+	        *(unsigned long *)(to+i) = *(unsigned long *)(from+i);
+}
+
+static inline void mips32_flush_cache_all_sc(void)
+{
+	unsigned long flags;
+
+	__save_and_cli(flags);
+	blast_dcache(); blast_icache(); blast_scache();
+	__restore_flags(flags);
+}
+
+static inline void mips32_flush_cache_all_pc(void)
+{
+	unsigned long flags;
+
+	__save_and_cli(flags);
+	blast_dcache(); blast_icache();
+	__restore_flags(flags);
+}
+
+static void
+mips32_flush_cache_range_sc(struct mm_struct *mm,
+			 unsigned long start,
+			 unsigned long end)
+{
+	struct vm_area_struct *vma;
+	unsigned long flags;
+
+	if(mm->context == 0)
+		return;
+
+	start &= PAGE_MASK;
+#ifdef DEBUG_CACHE
+	printk("crange[%d,%08lx,%08lx]", (int)mm->context, start, end);
+#endif
+	vma = find_vma(mm, start);
+	if(vma) {
+		if(mm->context != current->mm->context) {
+			mips32_flush_cache_all_sc();
+		} else {
+			pgd_t *pgd;
+			pmd_t *pmd;
+			pte_t *pte;
+
+			__save_and_cli(flags);
+			while(start < end) {
+				pgd = pgd_offset(mm, start);
+				pmd = pmd_offset(pgd, start);
+				pte = pte_offset(pmd, start);
+
+				if(pte_val(*pte) & _PAGE_VALID)
+					blast_scache_page(start);
+				start += PAGE_SIZE;
+			}
+			__restore_flags(flags);
+		}
+	}
+}
+
+static void mips32_flush_cache_range_pc(struct mm_struct *mm,
+				     unsigned long start,
+				     unsigned long end)
+{
+	if(mm->context != 0) {
+		unsigned long flags;
+
+#ifdef DEBUG_CACHE
+		printk("crange[%d,%08lx,%08lx]", (int)mm->context, start, end);
+#endif
+		__save_and_cli(flags);
+		blast_dcache(); blast_icache();
+		__restore_flags(flags);
+	}
+}
+
+/*
+ * On architectures like the Sparc, we could get rid of lines in
+ * the cache created only by a certain context, but on the MIPS
+ * (and actually certain Sparc's) we cannot.
+ */
+static void mips32_flush_cache_mm_sc(struct mm_struct *mm)
+{
+	if(mm->context != 0) {
+#ifdef DEBUG_CACHE
+		printk("cmm[%d]", (int)mm->context);
+#endif
+		mips32_flush_cache_all_sc();
+	}
+}
+
+static void mips32_flush_cache_mm_pc(struct mm_struct *mm)
+{
+	if(mm->context != 0) {
+#ifdef DEBUG_CACHE
+		printk("cmm[%d]", (int)mm->context);
+#endif
+		mips32_flush_cache_all_pc();
+	}
+}
+
+
+
+
+
+static void mips32_flush_cache_page_sc(struct vm_area_struct *vma,
+				    unsigned long page)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	unsigned long flags;
+	pgd_t *pgdp;
+	pmd_t *pmdp;
+	pte_t *ptep;
+
+	/*
+	 * If ownes no valid ASID yet, cannot possibly have gotten
+	 * this page into the cache.
+	 */
+	if (mm->context == 0)
+		return;
+
+#ifdef DEBUG_CACHE
+	printk("cpage[%d,%08lx]", (int)mm->context, page);
+#endif
+	__save_and_cli(flags);
+	page &= PAGE_MASK;
+	pgdp = pgd_offset(mm, page);
+	pmdp = pmd_offset(pgdp, page);
+	ptep = pte_offset(pmdp, page);
+
+	/*
+	 * If the page isn't marked valid, the page cannot possibly be
+	 * in the cache.
+	 */
+	if (!(pte_val(*ptep) & _PAGE_VALID))
+		goto out;
+
+	/*
+	 * Doing flushes for another ASID than the current one is
+	 * too difficult since 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->context != current->active_mm->context) {
+		/*
+		 * Do indexed flush, too much work to get the (possible)
+		 * tlb refills to work correctly.
+		 */
+		page = (KSEG0 + (page & (scache_size - 1)));
+		blast_dcache_page_indexed(page);
+		blast_scache_page_indexed(page);
+	} else
+		blast_scache_page(page);
+out:
+	__restore_flags(flags);
+}
+
+static void mips32_flush_cache_page_pc(struct vm_area_struct *vma,
+				    unsigned long page)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	unsigned long flags;
+	pgd_t *pgdp;
+	pmd_t *pmdp;
+	pte_t *ptep;
+
+	/*
+	 * If ownes no valid ASID yet, cannot possibly have gotten
+	 * this page into the cache.
+	 */
+	if (mm->context == 0)
+		return;
+
+#ifdef DEBUG_CACHE
+	printk("cpage[%d,%08lx]", (int)mm->context, page);
+#endif
+	__save_and_cli(flags);
+	page &= PAGE_MASK;
+	pgdp = pgd_offset(mm, page);
+	pmdp = pmd_offset(pgdp, page);
+	ptep = pte_offset(pmdp, page);
+
+	/*
+	 * If the page isn't marked valid, the page cannot possibly be
+	 * in the cache.
+	 */
+	if (!(pte_val(*ptep) & _PAGE_VALID))
+		goto out;
+
+	/*
+	 * Doing flushes for another ASID than the current one is
+	 * too difficult since Mips32 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) {
+		blast_dcache_page(page);
+	} else {
+		/* Do indexed flush, too much work to get the (possible)
+		 * tlb refills to work correctly.
+		 */
+		page = (KSEG0 + (page & (dcache_size - 1)));
+		blast_dcache_page_indexed(page);
+	}
+out:
+	__restore_flags(flags);
+}
+
+/* If the addresses passed to these routines are valid, they are
+ * either:
+ *
+ * 1) In KSEG0, so we can do a direct flush of the page.
+ * 2) In KSEG2, and since every process can translate those
+ *    addresses all the time in kernel mode we can do a direct
+ *    flush.
+ * 3) In KSEG1, no flush necessary.
+ */
+static void mips32_flush_page_to_ram_sc(struct page *page)
+{
+	blast_scache_page((unsigned long)page_address(page));
+}
+
+static void mips32_flush_page_to_ram_pc(struct page *page)
+{
+	blast_dcache_page((unsigned long)page_address(page));
+}
+
+static void
+mips32_flush_icache_page_s(struct vm_area_struct *vma, struct page *page)
+{
+	/*
+	 * We did an scache flush therefore PI is already clean.
+	 */
+}
+
+static void
+mips32_flush_icache_range(unsigned long start, unsigned long end)
+{
+	flush_cache_all();
+}
+
+static void
+mips32_flush_icache_page(struct vm_area_struct *vma, struct page *page)
+{
+	int address;
+
+	if (!(vma->vm_flags & VM_EXEC))
+		return;
+
+	address = KSEG0 + ((unsigned long)page_address(page) & PAGE_MASK & (dcache_size - 1));
+	blast_icache_page_indexed(address);
+}
+
+/*
+ * Writeback and invalidate the primary cache dcache before DMA.
+ */
+static void
+mips32_dma_cache_wback_inv_pc(unsigned long addr, unsigned long size)
+{
+	unsigned long end, a;
+	unsigned int flags;
+
+	if (size >= dcache_size) {
+		flush_cache_all();
+	} else {
+	        __save_and_cli(flags);
+		a = addr & ~(dc_lsize - 1);
+		end = (addr + size) & ~(dc_lsize - 1);
+		while (1) {
+			flush_dcache_line(a); /* Hit_Writeback_Inv_D */
+			if (a == end) break;
+			a += dc_lsize;
+		}
+		__restore_flags(flags);
+	}
+	bc_wback_inv(addr, size);
+}
+
+static void
+mips32_dma_cache_wback_inv_sc(unsigned long addr, unsigned long size)
+{
+	unsigned long end, a;
+
+	if (size >= scache_size) {
+		flush_cache_all();
+		return;
+	}
+
+	a = addr & ~(sc_lsize - 1);
+	end = (addr + size) & ~(sc_lsize - 1);
+	while (1) {
+		flush_scache_line(a);	/* Hit_Writeback_Inv_SD */
+		if (a == end) break;
+		a += sc_lsize;
+	}
+}
+
+static void
+mips32_dma_cache_inv_pc(unsigned long addr, unsigned long size)
+{
+	unsigned long end, a;
+	unsigned int flags;
+
+	if (size >= dcache_size) {
+		flush_cache_all();
+	} else {
+	        __save_and_cli(flags);
+		a = addr & ~(dc_lsize - 1);
+		end = (addr + size) & ~(dc_lsize - 1);
+		while (1) {
+			flush_dcache_line(a); /* Hit_Writeback_Inv_D */
+			if (a == end) break;
+			a += dc_lsize;
+		}
+		__restore_flags(flags);
+	}
+
+	bc_inv(addr, size);
+}
+
+static void
+mips32_dma_cache_inv_sc(unsigned long addr, unsigned long size)
+{
+	unsigned long end, a;
+
+	if (size >= scache_size) {
+		flush_cache_all();
+		return;
+	}
+
+	a = addr & ~(sc_lsize - 1);
+	end = (addr + size) & ~(sc_lsize - 1);
+	while (1) {
+		flush_scache_line(a); /* Hit_Writeback_Inv_SD */
+		if (a == end) break;
+		a += sc_lsize;
+	}
+}
+
+static void
+mips32_dma_cache_wback(unsigned long addr, unsigned long size)
+{
+	panic("mips32_dma_cache called - should not happen.\n");
+}
+
+/*
+ * 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 mips32_flush_cache_sigtramp(unsigned long addr)
+{
+	unsigned long daddr, iaddr;
+
+	daddr = addr & ~(dc_lsize - 1);
+	protected_writeback_dcache_line(daddr);
+	protected_writeback_dcache_line(daddr + dc_lsize);
+	iaddr = addr & ~(ic_lsize - 1);
+	protected_flush_icache_line(iaddr);
+	protected_flush_icache_line(iaddr + ic_lsize);
+}
+
+#undef DEBUG_TLB
+#undef DEBUG_TLBUPDATE
+
+void flush_tlb_all(void)
+{
+	unsigned long flags;
+	unsigned long old_ctx;
+	int entry;
+
+#ifdef DEBUG_TLB
+	printk("[tlball]");
+#endif
+
+	__save_and_cli(flags);
+	/* Save old context and create impossible VPN2 value */
+	old_ctx = (get_entryhi() & 0xff);
+	set_entryhi(KSEG0);
+	set_entrylo0(0);
+	set_entrylo1(0);
+	BARRIER;
+
+	entry = get_wired();
+
+	/* Blast 'em all away. */
+	while(entry < mips_cpu.tlbsize) {
+	        /* Make sure all entries differ. */  
+	        set_entryhi(KSEG0+entry*0x2000);
+		set_index(entry);
+		BARRIER;
+		tlb_write_indexed();
+		BARRIER;
+		entry++;
+	}
+	BARRIER;
+	set_entryhi(old_ctx);
+	__restore_flags(flags);
+}
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+	if (mm->context != 0) {
+		unsigned long flags;
+
+#ifdef DEBUG_TLB
+		printk("[tlbmm<%d>]", mm->context);
+#endif
+		__save_and_cli(flags);
+		get_new_mmu_context(mm, asid_cache);
+		if (mm == current->active_mm)
+			set_entryhi(mm->context & 0xff);
+		__restore_flags(flags);
+	}
+}
+
+void flush_tlb_range(struct mm_struct *mm, unsigned long start,
+				unsigned long end)
+{
+	if(mm->context != 0) {
+		unsigned long flags;
+		int size;
+
+#ifdef DEBUG_TLB
+		printk("[tlbrange<%02x,%08lx,%08lx>]", (mm->context & 0xff),
+		       start, end);
+#endif
+		__save_and_cli(flags);
+		size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+		size = (size + 1) >> 1;
+		if(size <= mips_cpu.tlbsize/2) {
+			int oldpid = (get_entryhi() & 0xff);
+			int newpid = (mm->context & 0xff);
+
+			start &= (PAGE_MASK << 1);
+			end += ((PAGE_SIZE << 1) - 1);
+			end &= (PAGE_MASK << 1);
+			while(start < end) {
+				int idx;
+
+				set_entryhi(start | newpid);
+				start += (PAGE_SIZE << 1);
+				BARRIER;
+				tlb_probe();
+				BARRIER;
+				idx = get_index();
+				set_entrylo0(0);
+				set_entrylo1(0);
+				if(idx < 0)
+					continue;
+				/* Make sure all entries differ. */
+				set_entryhi(KSEG0+idx*0x2000);
+				BARRIER;
+				tlb_write_indexed();
+				BARRIER;
+			}
+			set_entryhi(oldpid);
+		} else {
+			get_new_mmu_context(mm, asid_cache);
+			if (mm == current->active_mm)
+				set_entryhi(mm->context & 0xff);
+		}
+		__restore_flags(flags);
+	}
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+	if (vma->vm_mm->context != 0) {
+		unsigned long flags;
+		int oldpid, newpid, idx;
+
+#ifdef DEBUG_TLB
+		printk("[tlbpage<%d,%08lx>]", vma->vm_mm->context, page);
+#endif
+		newpid = (vma->vm_mm->context & 0xff);
+		page &= (PAGE_MASK << 1);
+		__save_and_cli(flags);
+		oldpid = (get_entryhi() & 0xff);
+		set_entryhi(page | newpid);
+		BARRIER;
+		tlb_probe();
+		BARRIER;
+		idx = get_index();
+		set_entrylo0(0);
+		set_entrylo1(0);
+		if(idx < 0)
+			goto finish;
+		/* Make sure all entries differ. */  
+		set_entryhi(KSEG0+idx*0x2000);
+		BARRIER;
+		tlb_write_indexed();
+
+	finish:
+		BARRIER;
+		set_entryhi(oldpid);
+		__restore_flags(flags);
+	}
+}
+
+void pgd_init(unsigned long page)
+{
+	unsigned long *p = (unsigned long *) page;
+	int i;
+
+	for(i = 0; i < USER_PTRS_PER_PGD; i+=8) {
+		p[i + 0] = (unsigned long) invalid_pte_table;
+		p[i + 1] = (unsigned long) invalid_pte_table;
+		p[i + 2] = (unsigned long) invalid_pte_table;
+		p[i + 3] = (unsigned long) invalid_pte_table;
+		p[i + 4] = (unsigned long) invalid_pte_table;
+		p[i + 5] = (unsigned long) invalid_pte_table;
+		p[i + 6] = (unsigned long) invalid_pte_table;
+		p[i + 7] = (unsigned long) invalid_pte_table;
+	}
+}
+
+/* 
+ * Updates the TLB with the new pte(s).
+ */
+void update_mmu_cache(struct vm_area_struct * vma,
+		      unsigned long address, pte_t pte)
+{
+	unsigned long flags;
+	pgd_t *pgdp;
+	pmd_t *pmdp;
+	pte_t *ptep;
+	int idx, pid;
+
+	/*
+	 * Handle debugger faulting in for debugee.
+	 */
+	if (current->active_mm != vma->vm_mm)
+		return;
+
+	pid = get_entryhi() & 0xff;
+
+#ifdef DEBUG_TLB
+	if((pid != (vma->vm_mm->context & 0xff)) || (vma->vm_mm->context == 0)) {
+		printk("update_mmu_cache: Wheee, bogus tlbpid mmpid=%d tlbpid=%d\n",
+		       (int) (vma->vm_mm->context & 0xff), pid);
+	}
+#endif
+
+	__save_and_cli(flags);
+	address &= (PAGE_MASK << 1);
+	set_entryhi(address | (pid));
+	pgdp = pgd_offset(vma->vm_mm, address);
+	BARRIER;
+	tlb_probe();
+	BARRIER;
+	pmdp = pmd_offset(pgdp, address);
+	idx = get_index();
+	ptep = pte_offset(pmdp, address);
+	BARRIER;
+	set_entrylo0(pte_val(*ptep++) >> 6);
+	set_entrylo1(pte_val(*ptep) >> 6);
+	set_entryhi(address | (pid));
+	BARRIER;
+	if(idx < 0) {
+		tlb_write_random();
+	} else {
+		tlb_write_indexed();
+	}
+	BARRIER;
+	set_entryhi(pid);
+	BARRIER;
+	__restore_flags(flags);
+}
+
+void show_regs(struct pt_regs * regs)
+{
+	/* Saved main processor registers. */
+	printk("$0 : %08lx %08lx %08lx %08lx\n",
+	       0UL, regs->regs[1], regs->regs[2], regs->regs[3]);
+	printk("$4 : %08lx %08lx %08lx %08lx\n",
+               regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]);
+	printk("$8 : %08lx %08lx %08lx %08lx\n",
+	       regs->regs[8], regs->regs[9], regs->regs[10], regs->regs[11]);
+	printk("$12: %08lx %08lx %08lx %08lx\n",
+               regs->regs[12], regs->regs[13], regs->regs[14], regs->regs[15]);
+	printk("$16: %08lx %08lx %08lx %08lx\n",
+	       regs->regs[16], regs->regs[17], regs->regs[18], regs->regs[19]);
+	printk("$20: %08lx %08lx %08lx %08lx\n",
+               regs->regs[20], regs->regs[21], regs->regs[22], regs->regs[23]);
+	printk("$24: %08lx %08lx\n",
+	       regs->regs[24], regs->regs[25]);
+	printk("$28: %08lx %08lx %08lx %08lx\n",
+	       regs->regs[28], regs->regs[29], regs->regs[30], regs->regs[31]);
+
+	/* Saved cp0 registers. */
+	printk("epc   : %08lx\nStatus: %08lx\nCause : %08lx\n",
+	       regs->cp0_epc, regs->cp0_status, regs->cp0_cause);
+}
+			
+void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
+				      unsigned long entryhi, unsigned long pagemask)
+{
+        unsigned long flags;
+        unsigned long wired;
+        unsigned long old_pagemask;
+        unsigned long old_ctx;
+
+        __save_and_cli(flags);
+        /* Save old context and create impossible VPN2 value */
+        old_ctx = (get_entryhi() & 0xff);
+        old_pagemask = get_pagemask();
+        wired = get_wired();
+        set_wired (wired + 1);
+        set_index (wired);
+        BARRIER;    
+        set_pagemask (pagemask);
+        set_entryhi(entryhi);
+        set_entrylo0(entrylo0);
+        set_entrylo1(entrylo1);
+        BARRIER;    
+        tlb_write_indexed();
+        BARRIER;    
+    
+        set_entryhi(old_ctx);
+        BARRIER;    
+        set_pagemask (old_pagemask);
+        flush_tlb_all();    
+        __restore_flags(flags);
+}
+
+/* Detect and size the various caches. */
+static void __init probe_icache(unsigned long config)
+{
+        unsigned long config1;
+	unsigned int lsize;
+
+        if (!(config & (1 << 31))) {
+	        /* 
+		 * Not a MIPS32 complainant CPU. 
+		 * Config 1 register not supported, we assume R4k style.
+		 */
+	        icache_size = 1 << (12 + ((config >> 9) & 7));
+		ic_lsize = 16 << ((config >> 5) & 1);
+		mips_cpu.icache.linesz = ic_lsize;
+		
+		/* 
+		 * We cannot infer associativity - assume direct map
+		 * unless probe template indicates otherwise
+		 */
+		if(!mips_cpu.icache.ways) mips_cpu.icache.ways = 1;
+		mips_cpu.icache.sets = 
+			(icache_size / ic_lsize) / mips_cpu.icache.ways;
+	} else {
+	       config1 = read_mips32_cp0_config1(); 
+
+	       if ((lsize = ((config1 >> 19) & 7)))
+		       mips_cpu.icache.linesz = 2 << lsize;
+	       else 
+		       mips_cpu.icache.linesz = lsize;
+	       mips_cpu.icache.sets = 64 << ((config1 >> 22) & 7);
+	       mips_cpu.icache.ways = 1 + ((config1 >> 16) & 7);
+
+	       ic_lsize = mips_cpu.icache.linesz;
+	       icache_size = mips_cpu.icache.sets * mips_cpu.icache.ways * 
+		             ic_lsize;
+	}
+	printk("Primary instruction cache %dkb, linesize %d bytes (%d ways)\n",
+	       icache_size >> 10, ic_lsize, mips_cpu.icache.ways);
+}
+
+static void __init probe_dcache(unsigned long config)
+{
+        unsigned long config1;
+	unsigned int lsize;
+
+        if (!(config & (1 << 31))) {
+	        /* 
+		 * Not a MIPS32 complainant CPU. 
+		 * Config 1 register not supported, we assume R4k style.
+		 */  
+		dcache_size = 1 << (12 + ((config >> 6) & 7));
+		dc_lsize = 16 << ((config >> 4) & 1);
+		mips_cpu.dcache.linesz = dc_lsize;
+		/* 
+		 * We cannot infer associativity - assume direct map
+		 * unless probe template indicates otherwise
+		 */
+		if(!mips_cpu.dcache.ways) mips_cpu.dcache.ways = 1;
+		mips_cpu.dcache.sets = 
+			(dcache_size / dc_lsize) / mips_cpu.dcache.ways;
+	} else {
+	        config1 = read_mips32_cp0_config1();
+
+		if ((lsize = ((config1 >> 10) & 7)))
+		        mips_cpu.dcache.linesz = 2 << lsize;
+		else 
+		        mips_cpu.dcache.linesz= lsize;
+		mips_cpu.dcache.sets = 64 << ((config1 >> 13) & 7);
+		mips_cpu.dcache.ways = 1 + ((config1 >> 7) & 7);
+
+		dc_lsize = mips_cpu.dcache.linesz;
+		dcache_size = 
+			mips_cpu.dcache.sets * mips_cpu.dcache.ways
+			* dc_lsize;
+	}
+	printk("Primary data cache %dkb, linesize %d bytes (%d ways)\n",
+	       dcache_size >> 10, dc_lsize, mips_cpu.dcache.ways);
+}
+
+
+/* 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(unsigned long config)
+{
+	extern unsigned long stext;
+	unsigned long flags, addr, begin, end, pow2;
+	int tmp;
+
+	if (mips_cpu.scache.flags == MIPS_CACHE_NOT_PRESENT)
+		return 0;
+
+	tmp = ((config >> 17) & 1);
+	if(tmp)
+		return 0;
+	tmp = ((config >> 22) & 3);
+	switch(tmp) {
+	case 0:
+		sc_lsize = 16;
+		break;
+	case 1:
+		sc_lsize = 32;
+		break;
+	case 2:
+		sc_lsize = 64;
+		break;
+	case 3:
+		sc_lsize = 128;
+		break;
+	}
+
+	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!
+	 */
+	__save_and_cli(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. */
+	set_taglo(0);
+	set_taghi(0);
+	__asm__ __volatile__("nop; nop; nop; nop;"); /* avoid the hazard */
+	__asm__ __volatile__("\n\t.set noreorder\n\t"
+			     ".set mips3\n\t"
+			     "cache 8, (%0)\n\t"
+			     ".set mips0\n\t"
+			     ".set reorder\n\t" : : "r" (begin));
+	__asm__ __volatile__("\n\t.set noreorder\n\t"
+			     ".set mips3\n\t"
+			     "cache 9, (%0)\n\t"
+			     ".set mips0\n\t"
+			     ".set reorder\n\t" : : "r" (begin));
+	__asm__ __volatile__("\n\t.set noreorder\n\t"
+			     ".set mips3\n\t"
+			     "cache 11, (%0)\n\t"
+			     ".set mips0\n\t"
+			     ".set reorder\n\t" : : "r" (begin));
+
+	/* Now search for the wrap around point. */
+	pow2 = (128 * 1024);
+	tmp = 0;
+	for(addr = (begin + (128 * 1024)); addr < (end); addr = (begin + pow2)) {
+		__asm__ __volatile__("\n\t.set noreorder\n\t"
+				     ".set mips3\n\t"
+				     "cache 7, (%0)\n\t"
+				     ".set mips0\n\t"
+				     ".set reorder\n\t" : : "r" (addr));
+		__asm__ __volatile__("nop; nop; nop; nop;"); /* hazard... */
+		if(!get_taglo())
+			break;
+		pow2 <<= 1;
+	}
+	__restore_flags(flags);
+	addr -= begin;
+	printk("Secondary cache sized at %dK linesize %d bytes.\n",
+	       (int) (addr >> 10), sc_lsize);
+	scache_size = addr;
+	return 1;
+}
+
+static void __init setup_noscache_funcs(void)
+{
+	_clear_page = (void *)mips32_clear_page_dc;
+	_copy_page = (void *)mips32_copy_page_dc;
+	_flush_cache_all = mips32_flush_cache_all_pc;
+	___flush_cache_all = mips32_flush_cache_all_pc;
+	_flush_cache_mm = mips32_flush_cache_mm_pc;
+	_flush_cache_range = mips32_flush_cache_range_pc;
+	_flush_cache_page = mips32_flush_cache_page_pc;
+	_flush_page_to_ram = mips32_flush_page_to_ram_pc;
+
+	_flush_icache_page = mips32_flush_icache_page;
+
+	_dma_cache_wback_inv = mips32_dma_cache_wback_inv_pc;
+	_dma_cache_wback = mips32_dma_cache_wback;
+	_dma_cache_inv = mips32_dma_cache_inv_pc;
+}
+
+static void __init setup_scache_funcs(void)
+{
+        _flush_cache_all = mips32_flush_cache_all_sc;
+        ___flush_cache_all = mips32_flush_cache_all_sc;
+	_flush_cache_mm = mips32_flush_cache_mm_sc;
+	_flush_cache_range = mips32_flush_cache_range_sc;
+	_flush_cache_page = mips32_flush_cache_page_sc;
+	_flush_page_to_ram = mips32_flush_page_to_ram_sc;
+	_clear_page = (void *)mips32_clear_page_sc;
+	_copy_page = (void *)mips32_copy_page_sc;
+
+	_flush_icache_page = mips32_flush_icache_page_s;
+
+	_dma_cache_wback_inv = mips32_dma_cache_wback_inv_sc;
+	_dma_cache_wback = mips32_dma_cache_wback;
+	_dma_cache_inv = mips32_dma_cache_inv_sc;
+}
+
+typedef int (*probe_func_t)(unsigned long);
+
+static inline void __init setup_scache(unsigned int config)
+{
+	probe_func_t probe_scache_kseg1;
+	int sc_present = 0;
+
+	/* Maybe the cpu knows about a l2 cache? */
+	probe_scache_kseg1 = (probe_func_t) (KSEG1ADDR(&probe_scache));
+	sc_present = probe_scache_kseg1(config);
+
+	if (sc_present) {
+	  	mips_cpu.scache.linesz = sc_lsize;
+		/* 
+		 * We cannot infer associativity - assume direct map
+		 * unless probe template indicates otherwise
+		 */
+		if(!mips_cpu.scache.ways) mips_cpu.scache.ways = 1;
+		mips_cpu.scache.sets = 
+		  (scache_size / sc_lsize) / mips_cpu.scache.ways;
+
+		setup_scache_funcs();
+		return;
+	}
+
+	setup_noscache_funcs();
+}
+
+static void __init probe_tlb(unsigned long config)
+{
+        unsigned long config1;
+
+        if (!(config & (1 << 31))) {
+	        /* 
+		 * Not a MIPS32 complainant CPU. 
+		 * Config 1 register not supported, we assume R4k style.
+		 */  
+	        mips_cpu.tlbsize = 48;
+	} else {
+	        config1 = read_mips32_cp0_config1();
+		if (!((config >> 7) & 3))
+		        panic("No MMU present");
+		else
+		        mips_cpu.tlbsize = ((config1 >> 25) & 0x3f) + 1;
+	}	
+
+	printk("Number of TLB entries %d.\n", mips_cpu.tlbsize);
+}
+
+void __init ld_mmu_mips32(void)
+{
+	unsigned long config = read_32bit_cp0_register(CP0_CONFIG);
+
+	printk("CPU revision is: %08x\n", read_32bit_cp0_register(CP0_PRID));
+
+#ifdef CONFIG_MIPS_UNCACHED
+	change_cp0_config(CONF_CM_CMASK, CONF_CM_UNCACHED);
+#else
+	change_cp0_config(CONF_CM_CMASK, CONF_CM_CACHABLE_NONCOHERENT);
+#endif
+
+	probe_icache(config);
+	probe_dcache(config);
+	setup_scache(config);
+	probe_tlb(config);
+
+	_flush_cache_sigtramp = mips32_flush_cache_sigtramp;
+	_flush_icache_range = mips32_flush_icache_range;	/* Ouch */
+
+	__flush_cache_all();
+	write_32bit_cp0_register(CP0_WIRED, 0);
+
+	/*
+	 * You should never change this register:
+	 *   - The entire mm handling assumes the c0_pagemask register to
+	 *     be set for 4kb pages.
+	 */
+	write_32bit_cp0_register(CP0_PAGEMASK, PM_4K);
+	flush_tlb_all();
+}