Hexagon: Implement basic TLB management routines for Hexagon.

/*

 * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that 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., 51 Franklin Street, Fifth Floor, Boston, MA

 * 02110-1301, USA.

 */

#ifndef _ASM_TLB_H

#define _ASM_TLB_H

#include <linux/pagemap.h>

#include <asm/tlbflush.h>

/*

 * We don't need any special per-pte or per-vma handling...

 */

#define tlb_start_vma(tlb, vma)				do { } while (0)

#define tlb_end_vma(tlb, vma)				do { } while (0)

#define __tlb_remove_tlb_entry(tlb, ptep, address)	do { } while (0)

/*

 * .. because we flush the whole mm when it fills up

 */

#define tlb_flush(tlb)		flush_tlb_mm((tlb)->mm)

#include <asm-generic/tlb.h>

#endif

/*

 * TLB flush support for Hexagon

 *

 * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that 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., 51 Franklin Street, Fifth Floor, Boston, MA

 * 02110-1301, USA.

 */

#ifndef _ASM_TLBFLUSH_H

#define _ASM_TLBFLUSH_H

#include <linux/mm.h>

#include <asm/processor.h>

/*

 * TLB flushing -- in "SMP", these routines get defined to be the

 * ones from smp.c, else they are some local flavors.

 */

/*

 * These functions are commonly macros, but in the interests of

 * VM vs. native implementation and code size, we simply declare

 * the function prototypes here.

 */

extern void tlb_flush_all(void);

extern void flush_tlb_mm(struct mm_struct *mm);

extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr);

extern void flush_tlb_range(struct vm_area_struct *vma,

				unsigned long start, unsigned long end);

extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);

extern void flush_tlb_one(unsigned long);

/*

 * "This is called in munmap when we have freed up some page-table pages.

 * We don't need to do anything here..."

 *

 * The VM kernel doesn't walk page tables, and they are passed to the VMM

 * by logical address. There doesn't seem to be any possibility that they

 * could be referenced by the VM kernel based on a stale mapping, since

 * they would only be located by consulting the mm structure, and they

 * will have been purged from that structure by the munmap.  Seems like

 * a noop on HVM as well.

 */

#define flush_tlb_pgtables(mm, start, end)

#endif

/*

 * Hexagon Virtual Machine TLB functions

 *

 * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that 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., 51 Franklin Street, Fifth Floor, Boston, MA

 * 02110-1301, USA.

 */

/*

 * The Hexagon Virtual Machine conceals the real workings of

 * the TLB, but there are one or two functions that need to

 * be instantiated for it, differently from a native build.

 */

#include <linux/mm.h>

#include <asm/page.h>

#include <asm/hexagon_vm.h>

/*

 * Initial VM implementation has only one map active at a time, with

 * TLB purgings on changes.  So either we're nuking the current map,

 * or it's a no-op.  This operation is messy on true SMPs where other

 * processors must be induced to flush the copies in their local TLBs,

 * but Hexagon thread-based virtual processors share the same MMU.

 */

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.ptbase == current->active_mm->context.ptbase)

		__vmclrmap((void *)start, end - start);

}

/*

 * Flush a page from the kernel virtual map - used by highmem

 */

void flush_tlb_one(unsigned long vaddr)

{

	__vmclrmap((void *)vaddr, PAGE_SIZE);

}

/*

 * Flush all TLBs across all CPUs, virtual or real.

 * A single Hexagon core has 6 thread contexts but

 * only one TLB.

 */

void tlb_flush_all(void)

{

	/*  should probably use that fixaddr end or whateve label  */

	__vmclrmap(0, 0xffff0000);

}

/*

 * Flush TLB entries associated with a given mm_struct mapping.

 */

void flush_tlb_mm(struct mm_struct *mm)

{

	/* Current Virtual Machine has only one map active at a time */

	if (current->active_mm->context.ptbase == mm->context.ptbase)

		tlb_flush_all();

}

/*

 * Flush TLB state associated with a page of a vma.

 */

void flush_tlb_page(struct vm_area_struct *vma, unsigned long vaddr)

{

	struct mm_struct *mm = vma->vm_mm;

	if (mm->context.ptbase  == current->active_mm->context.ptbase)

		__vmclrmap((void *)vaddr, PAGE_SIZE);

}

/*

 * Flush TLB entries associated with a kernel address range.

 * Like flush range, but without the check on the vma->vm_mm.

 */

void flush_tlb_kernel_range(unsigned long start, unsigned long end)

{

		__vmclrmap((void *)start, end - start);

}