arch/avr32/mm/tlb.c - kernel/bruno - Git at Google

 /*
  * AVR32 TLB operations
  *
  * Copyright (C) 2004-2006 Atmel Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
 #include <linux/mm.h>

 #include <asm/mmu_context.h>

 /* TODO: Get the correct number from the CONFIG1 system register */
 #define NR_TLB_ENTRIES 32

 static void show_dtlb_entry(unsigned int index)
 {
 	u32 tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save;
 	unsigned long flags;

 	local_irq_save(flags);
 	mmucr_save = sysreg_read(MMUCR);
 	tlbehi_save = sysreg_read(TLBEHI);
 	mmucr = SYSREG_BFINS(DRP, index, mmucr_save);
 	sysreg_write(MMUCR, mmucr);

 	__builtin_tlbr();
 	cpu_sync_pipeline();

 	tlbehi = sysreg_read(TLBEHI);
 	tlbelo = sysreg_read(TLBELO);

 	printk("%2u: %c %c %02x   %05x %05x %o  %o  %c %c %c %c\n",
 	       index,
 	       SYSREG_BFEXT(TLBEHI_V, tlbehi) ? '1' : '0',
 	       SYSREG_BFEXT(G, tlbelo) ? '1' : '0',
 	       SYSREG_BFEXT(ASID, tlbehi),
 	       SYSREG_BFEXT(VPN, tlbehi) >> 2,
 	       SYSREG_BFEXT(PFN, tlbelo) >> 2,
 	       SYSREG_BFEXT(AP, tlbelo),
 	       SYSREG_BFEXT(SZ, tlbelo),
 	       SYSREG_BFEXT(TLBELO_C, tlbelo) ? 'C' : ' ',
 	       SYSREG_BFEXT(B, tlbelo) ? 'B' : ' ',
 	       SYSREG_BFEXT(W, tlbelo) ? 'W' : ' ',
 	       SYSREG_BFEXT(TLBELO_D, tlbelo) ? 'D' : ' ');

 	sysreg_write(MMUCR, mmucr_save);
 	sysreg_write(TLBEHI, tlbehi_save);
 	cpu_sync_pipeline();
 	local_irq_restore(flags);
 }

 void dump_dtlb(void)
 {
 	unsigned int i;

 	printk("ID  V G ASID VPN   PFN   AP SZ C B W D\n");
 	for (i = 0; i < NR_TLB_ENTRIES; i++)
 		show_dtlb_entry(i);
 }

 static void update_dtlb(unsigned long address, pte_t pte)
 {
 	u32 tlbehi;
 	u32 mmucr;

 	/*
 	 * We're not changing the ASID here, so no need to flush the
 	 * pipeline.
 	 */
 	tlbehi = sysreg_read(TLBEHI);
 	tlbehi = SYSREG_BF(ASID, SYSREG_BFEXT(ASID, tlbehi));
 	tlbehi |= address & MMU_VPN_MASK;
 	tlbehi |= SYSREG_BIT(TLBEHI_V);
 	sysreg_write(TLBEHI, tlbehi);

 	/* Does this mapping already exist? */
 	__builtin_tlbs();
 	mmucr = sysreg_read(MMUCR);

 	if (mmucr & SYSREG_BIT(MMUCR_N)) {
 		/* Not found -- pick a not-recently-accessed entry */
 		unsigned int rp;
 		u32 tlbar = sysreg_read(TLBARLO);

 		rp = 32 - fls(tlbar);
 		if (rp == 32) {
 			rp = 0;
 			sysreg_write(TLBARLO, -1L);
 		}

 		mmucr = SYSREG_BFINS(DRP, rp, mmucr);
 		sysreg_write(MMUCR, mmucr);
 	}

 	sysreg_write(TLBELO, pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK);

 	/* Let's go */
 	__builtin_tlbw();
 }

 void update_mmu_cache(struct vm_area_struct *vma,
 		      unsigned long address, pte_t *ptep)
 {
 	unsigned long flags;

 	/* ptrace may call this routine */
 	if (vma && current->active_mm != vma->vm_mm)
 		return;

 	local_irq_save(flags);
 	update_dtlb(address, *ptep);
 	local_irq_restore(flags);
 }

 static void __flush_tlb_page(unsigned long asid, unsigned long page)
 {
 	u32 mmucr, tlbehi;

 	/*
 	 * Caller is responsible for masking out non-PFN bits in page
 	 * and changing the current ASID if necessary. This means that
 	 * we don't need to flush the pipeline after writing TLBEHI.
 	 */
 	tlbehi = page | asid;
 	sysreg_write(TLBEHI, tlbehi);

 	__builtin_tlbs();
 	mmucr = sysreg_read(MMUCR);

 	if (!(mmucr & SYSREG_BIT(MMUCR_N))) {
 		unsigned int entry;
 		u32 tlbarlo;

 		/* Clear the "valid" bit */
 		sysreg_write(TLBEHI, tlbehi);

 		/* mark the entry as "not accessed" */
 		entry = SYSREG_BFEXT(DRP, mmucr);
 		tlbarlo = sysreg_read(TLBARLO);
 		tlbarlo |= (0x80000000UL >> entry);
 		sysreg_write(TLBARLO, tlbarlo);

 		/* update the entry with valid bit clear */
 		__builtin_tlbw();
 	}
 }

 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 {
 	if (vma->vm_mm && vma->vm_mm->context != NO_CONTEXT) {
 		unsigned long flags, asid;
 		unsigned long saved_asid = MMU_NO_ASID;

 		asid = vma->vm_mm->context & MMU_CONTEXT_ASID_MASK;
 		page &= PAGE_MASK;

 		local_irq_save(flags);
 		if (vma->vm_mm != current->mm) {
 			saved_asid = get_asid();
 			set_asid(asid);
 		}

 		__flush_tlb_page(asid, page);

 		if (saved_asid != MMU_NO_ASID)
 			set_asid(saved_asid);
 		local_irq_restore(flags);
 	}
 }

 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 		     unsigned long end)
 {
 	struct mm_struct *mm = vma->vm_mm;

 	if (mm->context != NO_CONTEXT) {
 		unsigned long flags;
 		int size;

 		local_irq_save(flags);
 		size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;

 		if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */
 			mm->context = NO_CONTEXT;
 			if (mm == current->mm)
 				activate_context(mm);
 		} else {
 			unsigned long asid;
 			unsigned long saved_asid;

 			asid = mm->context & MMU_CONTEXT_ASID_MASK;
 			saved_asid = MMU_NO_ASID;

 			start &= PAGE_MASK;
 			end += (PAGE_SIZE - 1);
 			end &= PAGE_MASK;

 			if (mm != current->mm) {
 				saved_asid = get_asid();
 				set_asid(asid);
 			}

 			while (start < end) {
 				__flush_tlb_page(asid, start);
 				start += PAGE_SIZE;
 			}
 			if (saved_asid != MMU_NO_ASID)
 				set_asid(saved_asid);
 		}
 		local_irq_restore(flags);
 	}
 }

 /*
  * This function depends on the pages to be flushed having the G
  * (global) bit set in their pte. This is true for all
  * PAGE_KERNEL(_RO) pages.
  */
 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 {
 	unsigned long flags;
 	int size;

 	size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 	if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */
 		flush_tlb_all();
 	} else {
 		unsigned long asid;

 		local_irq_save(flags);
 		asid = get_asid();

 		start &= PAGE_MASK;
 		end += (PAGE_SIZE - 1);
 		end &= PAGE_MASK;

 		while (start < end) {
 			__flush_tlb_page(asid, start);
 			start += PAGE_SIZE;
 		}
 		local_irq_restore(flags);
 	}
 }

 void flush_tlb_mm(struct mm_struct *mm)
 {
 	/* Invalidate all TLB entries of this process by getting a new ASID */
 	if (mm->context != NO_CONTEXT) {
 		unsigned long flags;

 		local_irq_save(flags);
 		mm->context = NO_CONTEXT;
 		if (mm == current->mm)
 			activate_context(mm);
 		local_irq_restore(flags);
 	}
 }

 void flush_tlb_all(void)
 {
 	unsigned long flags;

 	local_irq_save(flags);
 	sysreg_write(MMUCR, sysreg_read(MMUCR) | SYSREG_BIT(MMUCR_I));
 	local_irq_restore(flags);
 }

 #ifdef CONFIG_PROC_FS

 #include <linux/seq_file.h>
 #include <linux/proc_fs.h>
 #include <linux/init.h>

 static void *tlb_start(struct seq_file *tlb, loff_t *pos)
 {
 	static unsigned long tlb_index;

 	if (*pos >= NR_TLB_ENTRIES)
 		return NULL;

 	tlb_index = 0;
 	return &tlb_index;
 }

 static void *tlb_next(struct seq_file *tlb, void *v, loff_t *pos)
 {
 	unsigned long *index = v;

 	if (*index >= NR_TLB_ENTRIES - 1)
 		return NULL;

 	++*pos;
 	++*index;
 	return index;
 }

 static void tlb_stop(struct seq_file *tlb, void *v)
 {

 }

 static int tlb_show(struct seq_file *tlb, void *v)
 {
 	unsigned int tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save;
 	unsigned long flags;
 	unsigned long *index = v;

 	if (*index == 0)
 		seq_puts(tlb, "ID  V G ASID VPN   PFN   AP SZ C B W D\n");

 	BUG_ON(*index >= NR_TLB_ENTRIES);

 	local_irq_save(flags);
 	mmucr_save = sysreg_read(MMUCR);
 	tlbehi_save = sysreg_read(TLBEHI);
 	mmucr = SYSREG_BFINS(DRP, *index, mmucr_save);
 	sysreg_write(MMUCR, mmucr);

 	/* TLBR might change the ASID */
 	__builtin_tlbr();
 	cpu_sync_pipeline();

 	tlbehi = sysreg_read(TLBEHI);
 	tlbelo = sysreg_read(TLBELO);

 	sysreg_write(MMUCR, mmucr_save);
 	sysreg_write(TLBEHI, tlbehi_save);
 	cpu_sync_pipeline();
 	local_irq_restore(flags);

 	seq_printf(tlb, "%2lu: %c %c %02x   %05x %05x %o  %o  %c %c %c %c\n",
 		   *index,
 		   SYSREG_BFEXT(TLBEHI_V, tlbehi) ? '1' : '0',
 		   SYSREG_BFEXT(G, tlbelo) ? '1' : '0',
 		   SYSREG_BFEXT(ASID, tlbehi),
 		   SYSREG_BFEXT(VPN, tlbehi) >> 2,
 		   SYSREG_BFEXT(PFN, tlbelo) >> 2,
 		   SYSREG_BFEXT(AP, tlbelo),
 		   SYSREG_BFEXT(SZ, tlbelo),
 		   SYSREG_BFEXT(TLBELO_C, tlbelo) ? '1' : '0',
 		   SYSREG_BFEXT(B, tlbelo) ? '1' : '0',
 		   SYSREG_BFEXT(W, tlbelo) ? '1' : '0',
 		   SYSREG_BFEXT(TLBELO_D, tlbelo) ? '1' : '0');

 	return 0;
 }

 static const struct seq_operations tlb_ops = {
 	.start		= tlb_start,
 	.next		= tlb_next,
 	.stop		= tlb_stop,
 	.show		= tlb_show,
 };

 static int tlb_open(struct inode *inode, struct file *file)
 {
 	return seq_open(file, &tlb_ops);
 }

 static const struct file_operations proc_tlb_operations = {
 	.open		= tlb_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };

 static int __init proctlb_init(void)
 {
 	proc_create("tlb", 0, NULL, &proc_tlb_operations);
 	return 0;
 }
 late_initcall(proctlb_init);
 #endif /* CONFIG_PROC_FS */
	/*
	* AVR32 TLB operations
	*
	* Copyright (C) 2004-2006 Atmel Corporation
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/
	#include <linux/mm.h>

	#include <asm/mmu_context.h>

	/* TODO: Get the correct number from the CONFIG1 system register */
	#define NR_TLB_ENTRIES 32

	static void show_dtlb_entry(unsigned int index)
	{
	u32 tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save;
	unsigned long flags;

	local_irq_save(flags);
	mmucr_save = sysreg_read(MMUCR);
	tlbehi_save = sysreg_read(TLBEHI);
	mmucr = SYSREG_BFINS(DRP, index, mmucr_save);
	sysreg_write(MMUCR, mmucr);

	__builtin_tlbr();
	cpu_sync_pipeline();

	tlbehi = sysreg_read(TLBEHI);
	tlbelo = sysreg_read(TLBELO);

	printk("%2u: %c %c %02x %05x %05x %o %o %c %c %c %c\n",
	index,
	SYSREG_BFEXT(TLBEHI_V, tlbehi) ? '1' : '0',
	SYSREG_BFEXT(G, tlbelo) ? '1' : '0',
	SYSREG_BFEXT(ASID, tlbehi),
	SYSREG_BFEXT(VPN, tlbehi) >> 2,
	SYSREG_BFEXT(PFN, tlbelo) >> 2,
	SYSREG_BFEXT(AP, tlbelo),
	SYSREG_BFEXT(SZ, tlbelo),
	SYSREG_BFEXT(TLBELO_C, tlbelo) ? 'C' : ' ',
	SYSREG_BFEXT(B, tlbelo) ? 'B' : ' ',
	SYSREG_BFEXT(W, tlbelo) ? 'W' : ' ',
	SYSREG_BFEXT(TLBELO_D, tlbelo) ? 'D' : ' ');

	sysreg_write(MMUCR, mmucr_save);
	sysreg_write(TLBEHI, tlbehi_save);
	cpu_sync_pipeline();
	local_irq_restore(flags);
	}

	void dump_dtlb(void)
	{
	unsigned int i;

	printk("ID V G ASID VPN PFN AP SZ C B W D\n");
	for (i = 0; i < NR_TLB_ENTRIES; i++)
	show_dtlb_entry(i);
	}

	static void update_dtlb(unsigned long address, pte_t pte)
	{
	u32 tlbehi;
	u32 mmucr;

	/*
	* We're not changing the ASID here, so no need to flush the
	* pipeline.
	*/
	tlbehi = sysreg_read(TLBEHI);
	tlbehi = SYSREG_BF(ASID, SYSREG_BFEXT(ASID, tlbehi));
	tlbehi \|= address & MMU_VPN_MASK;
	tlbehi \|= SYSREG_BIT(TLBEHI_V);
	sysreg_write(TLBEHI, tlbehi);

	/* Does this mapping already exist? */
	__builtin_tlbs();
	mmucr = sysreg_read(MMUCR);

	if (mmucr & SYSREG_BIT(MMUCR_N)) {
	/* Not found -- pick a not-recently-accessed entry */
	unsigned int rp;
	u32 tlbar = sysreg_read(TLBARLO);

	rp = 32 - fls(tlbar);
	if (rp == 32) {
	rp = 0;
	sysreg_write(TLBARLO, -1L);
	}

	mmucr = SYSREG_BFINS(DRP, rp, mmucr);
	sysreg_write(MMUCR, mmucr);
	}

	sysreg_write(TLBELO, pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK);

	/* Let's go */
	__builtin_tlbw();
	}

	void update_mmu_cache(struct vm_area_struct *vma,
	unsigned long address, pte_t *ptep)
	{
	unsigned long flags;

	/* ptrace may call this routine */
	if (vma && current->active_mm != vma->vm_mm)
	return;

	local_irq_save(flags);
	update_dtlb(address, *ptep);
	local_irq_restore(flags);
	}

	static void __flush_tlb_page(unsigned long asid, unsigned long page)
	{
	u32 mmucr, tlbehi;

	/*
	* Caller is responsible for masking out non-PFN bits in page
	* and changing the current ASID if necessary. This means that
	* we don't need to flush the pipeline after writing TLBEHI.
	*/
	tlbehi = page \| asid;
	sysreg_write(TLBEHI, tlbehi);

	__builtin_tlbs();
	mmucr = sysreg_read(MMUCR);

	if (!(mmucr & SYSREG_BIT(MMUCR_N))) {
	unsigned int entry;
	u32 tlbarlo;

	/* Clear the "valid" bit */
	sysreg_write(TLBEHI, tlbehi);

	/* mark the entry as "not accessed" */
	entry = SYSREG_BFEXT(DRP, mmucr);
	tlbarlo = sysreg_read(TLBARLO);
	tlbarlo \|= (0x80000000UL >> entry);
	sysreg_write(TLBARLO, tlbarlo);

	/* update the entry with valid bit clear */
	__builtin_tlbw();
	}
	}

	void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
	{
	if (vma->vm_mm && vma->vm_mm->context != NO_CONTEXT) {
	unsigned long flags, asid;
	unsigned long saved_asid = MMU_NO_ASID;

	asid = vma->vm_mm->context & MMU_CONTEXT_ASID_MASK;
	page &= PAGE_MASK;

	local_irq_save(flags);
	if (vma->vm_mm != current->mm) {
	saved_asid = get_asid();
	set_asid(asid);
	}

	__flush_tlb_page(asid, page);

	if (saved_asid != MMU_NO_ASID)
	set_asid(saved_asid);
	local_irq_restore(flags);
	}
	}

	void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
	unsigned long end)
	{
	struct mm_struct *mm = vma->vm_mm;

	if (mm->context != NO_CONTEXT) {
	unsigned long flags;
	int size;

	local_irq_save(flags);
	size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;

	if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */
	mm->context = NO_CONTEXT;
	if (mm == current->mm)
	activate_context(mm);
	} else {
	unsigned long asid;
	unsigned long saved_asid;

	asid = mm->context & MMU_CONTEXT_ASID_MASK;
	saved_asid = MMU_NO_ASID;

	start &= PAGE_MASK;
	end += (PAGE_SIZE - 1);
	end &= PAGE_MASK;

	if (mm != current->mm) {
	saved_asid = get_asid();
	set_asid(asid);
	}

	while (start < end) {
	__flush_tlb_page(asid, start);
	start += PAGE_SIZE;
	}
	if (saved_asid != MMU_NO_ASID)
	set_asid(saved_asid);
	}
	local_irq_restore(flags);
	}
	}

	/*
	* This function depends on the pages to be flushed having the G
	* (global) bit set in their pte. This is true for all
	* PAGE_KERNEL(_RO) pages.
	*/
	void flush_tlb_kernel_range(unsigned long start, unsigned long end)
	{
	unsigned long flags;
	int size;

	size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
	if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */
	flush_tlb_all();
	} else {
	unsigned long asid;

	local_irq_save(flags);
	asid = get_asid();

	start &= PAGE_MASK;
	end += (PAGE_SIZE - 1);
	end &= PAGE_MASK;

	while (start < end) {
	__flush_tlb_page(asid, start);
	start += PAGE_SIZE;
	}
	local_irq_restore(flags);
	}
	}

	void flush_tlb_mm(struct mm_struct *mm)
	{
	/* Invalidate all TLB entries of this process by getting a new ASID */
	if (mm->context != NO_CONTEXT) {
	unsigned long flags;

	local_irq_save(flags);
	mm->context = NO_CONTEXT;
	if (mm == current->mm)
	activate_context(mm);
	local_irq_restore(flags);
	}
	}

	void flush_tlb_all(void)
	{
	unsigned long flags;

	local_irq_save(flags);
	sysreg_write(MMUCR, sysreg_read(MMUCR) \| SYSREG_BIT(MMUCR_I));
	local_irq_restore(flags);
	}

	#ifdef CONFIG_PROC_FS

	#include <linux/seq_file.h>
	#include <linux/proc_fs.h>
	#include <linux/init.h>

	static void tlb_start(struct seq_file tlb, loff_t *pos)
	{
	static unsigned long tlb_index;

	if (*pos >= NR_TLB_ENTRIES)
	return NULL;

	tlb_index = 0;
	return &tlb_index;
	}

	static void tlb_next(struct seq_file tlb, void v, loff_t pos)
	{
	unsigned long *index = v;

	if (*index >= NR_TLB_ENTRIES - 1)
	return NULL;

	++*pos;
	++*index;
	return index;
	}

	static void tlb_stop(struct seq_file tlb, void v)
	{

	}

	static int tlb_show(struct seq_file tlb, void v)
	{
	unsigned int tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save;
	unsigned long flags;
	unsigned long *index = v;

	if (*index == 0)
	seq_puts(tlb, "ID V G ASID VPN PFN AP SZ C B W D\n");

	BUG_ON(*index >= NR_TLB_ENTRIES);

	local_irq_save(flags);
	mmucr_save = sysreg_read(MMUCR);
	tlbehi_save = sysreg_read(TLBEHI);
	mmucr = SYSREG_BFINS(DRP, *index, mmucr_save);
	sysreg_write(MMUCR, mmucr);

	/* TLBR might change the ASID */
	__builtin_tlbr();
	cpu_sync_pipeline();

	tlbehi = sysreg_read(TLBEHI);
	tlbelo = sysreg_read(TLBELO);

	sysreg_write(MMUCR, mmucr_save);
	sysreg_write(TLBEHI, tlbehi_save);
	cpu_sync_pipeline();
	local_irq_restore(flags);

	seq_printf(tlb, "%2lu: %c %c %02x %05x %05x %o %o %c %c %c %c\n",
	*index,
	SYSREG_BFEXT(TLBEHI_V, tlbehi) ? '1' : '0',
	SYSREG_BFEXT(G, tlbelo) ? '1' : '0',
	SYSREG_BFEXT(ASID, tlbehi),
	SYSREG_BFEXT(VPN, tlbehi) >> 2,
	SYSREG_BFEXT(PFN, tlbelo) >> 2,
	SYSREG_BFEXT(AP, tlbelo),
	SYSREG_BFEXT(SZ, tlbelo),
	SYSREG_BFEXT(TLBELO_C, tlbelo) ? '1' : '0',
	SYSREG_BFEXT(B, tlbelo) ? '1' : '0',
	SYSREG_BFEXT(W, tlbelo) ? '1' : '0',
	SYSREG_BFEXT(TLBELO_D, tlbelo) ? '1' : '0');

	return 0;
	}

	static const struct seq_operations tlb_ops = {
	.start = tlb_start,
	.next = tlb_next,
	.stop = tlb_stop,
	.show = tlb_show,
	};

	static int tlb_open(struct inode inode, struct file file)
	{
	return seq_open(file, &tlb_ops);
	}

	static const struct file_operations proc_tlb_operations = {
	.open = tlb_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
	};

	static int __init proctlb_init(void)
	{
	proc_create("tlb", 0, NULL, &proc_tlb_operations);
	return 0;
	}
	late_initcall(proctlb_init);
	#endif /* CONFIG_PROC_FS */