linux-stable-rt/arch/sh/mm/tlb-flush.c

/*
 * TLB flushing operations for SH with an MMU.
 *
 *  Copyright (C) 1999  Niibe Yutaka
 *  Copyright (C) 2003  Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/mm.h>
#include <asm/mmu_context.h>
#include <asm/tlbflush.h>

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;
		unsigned long 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_NTLB_ENTRIES/4)) { /* Too many TLB to flush */
			mm->context = NO_CONTEXT;
			if (mm == current->mm)
				activate_context(mm);
		} else {
			unsigned long asid = mm->context&MMU_CONTEXT_ASID_MASK;
			unsigned long 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);
	}
}

void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
	unsigned long flags;
	int size;

	local_irq_save(flags);
	size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
	if (size > (MMU_NTLB_ENTRIES/4)) { /* Too many TLB to flush */
		flush_tlb_all();
	} else {
		unsigned long asid = init_mm.context&MMU_CONTEXT_ASID_MASK;
		unsigned long saved_asid = get_asid();

		start &= PAGE_MASK;
		end += (PAGE_SIZE - 1);
		end &= PAGE_MASK;
		set_asid(asid);
		while (start < end) {
			__flush_tlb_page(asid, start);
			start += PAGE_SIZE;
		}
		set_asid(saved_asid);
	}
	local_irq_restore(flags);
}

void flush_tlb_mm(struct mm_struct *mm)
{
	/* Invalidate all TLB of this process. */
	/* Instead of invalidating each TLB, we get new MMU context. */
	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, status;

	/*
	 * Flush all the TLB.
	 *
	 * Write to the MMU control register's bit:
	 *	TF-bit for SH-3, TI-bit for SH-4.
	 *      It's same position, bit #2.
	 */
	local_irq_save(flags);
	status = ctrl_inl(MMUCR);
	status |= 0x04;
	ctrl_outl(status, MMUCR);
	ctrl_barrier();
	local_irq_restore(flags);
}