alistair23-linux/arch/xtensa/include/asm/tlbflush.h

/*
 * 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.
 *
 * Copyright (C) 2001 - 2013 Tensilica Inc.
 */

#ifndef _XTENSA_TLBFLUSH_H
#define _XTENSA_TLBFLUSH_H

#include <linux/stringify.h>
#include <asm/processor.h>

#define DTLB_WAY_PGD	7

#define ITLB_ARF_WAYS	4
#define DTLB_ARF_WAYS	4

#define ITLB_HIT_BIT	3
#define DTLB_HIT_BIT	4

#ifndef __ASSEMBLY__

/* TLB flushing:
 *
 *  - flush_tlb_all() flushes all processes TLB entries
 *  - flush_tlb_mm(mm) flushes the specified mm context TLB entries
 *  - flush_tlb_page(mm, vmaddr) flushes a single page
 *  - flush_tlb_range(mm, start, end) flushes a range of pages
 */

void local_flush_tlb_all(void);
void local_flush_tlb_mm(struct mm_struct *mm);
void local_flush_tlb_page(struct vm_area_struct *vma,
		unsigned long page);
void local_flush_tlb_range(struct vm_area_struct *vma,
		unsigned long start, unsigned long end);
void local_flush_tlb_kernel_range(unsigned long start, unsigned long end);

#ifdef CONFIG_SMP

void flush_tlb_all(void);
void flush_tlb_mm(struct mm_struct *);
void flush_tlb_page(struct vm_area_struct *, unsigned long);
void flush_tlb_range(struct vm_area_struct *, unsigned long,
		unsigned long);
void flush_tlb_kernel_range(unsigned long start, unsigned long end);

#else /* !CONFIG_SMP */

#define flush_tlb_all()			   local_flush_tlb_all()
#define flush_tlb_mm(mm)		   local_flush_tlb_mm(mm)
#define flush_tlb_page(vma, page)	   local_flush_tlb_page(vma, page)
#define flush_tlb_range(vma, vmaddr, end)  local_flush_tlb_range(vma, vmaddr, \
								 end)
#define flush_tlb_kernel_range(start, end) local_flush_tlb_kernel_range(start, \
									end)

#endif /* CONFIG_SMP */

/* TLB operations. */

static inline unsigned long itlb_probe(unsigned long addr)
{
	unsigned long tmp;
	__asm__ __volatile__("pitlb  %0, %1\n\t" : "=a" (tmp) : "a" (addr));
	return tmp;
}

static inline unsigned long dtlb_probe(unsigned long addr)
{
	unsigned long tmp;
	__asm__ __volatile__("pdtlb  %0, %1\n\t" : "=a" (tmp) : "a" (addr));
	return tmp;
}

static inline void invalidate_itlb_entry (unsigned long probe)
{
	__asm__ __volatile__("iitlb  %0; isync\n\t" : : "a" (probe));
}

static inline void invalidate_dtlb_entry (unsigned long probe)
{
	__asm__ __volatile__("idtlb  %0; dsync\n\t" : : "a" (probe));
}

/* Use the .._no_isync functions with caution.  Generally, these are
 * handy for bulk invalidates followed by a single 'isync'.  The
 * caller must follow up with an 'isync', which can be relatively
 * expensive on some Xtensa implementations.
 */
static inline void invalidate_itlb_entry_no_isync (unsigned entry)
{
	/* Caller must follow up with 'isync'. */
	__asm__ __volatile__ ("iitlb  %0\n" : : "a" (entry) );
}

static inline void invalidate_dtlb_entry_no_isync (unsigned entry)
{
	/* Caller must follow up with 'isync'. */
	__asm__ __volatile__ ("idtlb  %0\n" : : "a" (entry) );
}

static inline void set_itlbcfg_register (unsigned long val)
{
	__asm__ __volatile__("wsr  %0, itlbcfg\n\t" "isync\n\t"
			     : : "a" (val));
}

static inline void set_dtlbcfg_register (unsigned long val)
{
	__asm__ __volatile__("wsr  %0, dtlbcfg; dsync\n\t"
	    		     : : "a" (val));
}

static inline void set_ptevaddr_register (unsigned long val)
{
	__asm__ __volatile__(" wsr  %0, ptevaddr; isync\n"
			     : : "a" (val));
}

static inline unsigned long read_ptevaddr_register (void)
{
	unsigned long tmp;
	__asm__ __volatile__("rsr  %0, ptevaddr\n\t" : "=a" (tmp));
	return tmp;
}

static inline void write_dtlb_entry (pte_t entry, int way)
{
	__asm__ __volatile__("wdtlb  %1, %0; dsync\n\t"
			     : : "r" (way), "r" (entry) );
}

static inline void write_itlb_entry (pte_t entry, int way)
{
	__asm__ __volatile__("witlb  %1, %0; isync\n\t"
	                     : : "r" (way), "r" (entry) );
}

static inline void invalidate_page_directory (void)
{
	invalidate_dtlb_entry (DTLB_WAY_PGD);
	invalidate_dtlb_entry (DTLB_WAY_PGD+1);
	invalidate_dtlb_entry (DTLB_WAY_PGD+2);
}

static inline void invalidate_itlb_mapping (unsigned address)
{
	unsigned long tlb_entry;
	if (((tlb_entry = itlb_probe(address)) & (1 << ITLB_HIT_BIT)) != 0)
		invalidate_itlb_entry(tlb_entry);
}

static inline void invalidate_dtlb_mapping (unsigned address)
{
	unsigned long tlb_entry;
	if (((tlb_entry = dtlb_probe(address)) & (1 << DTLB_HIT_BIT)) != 0)
		invalidate_dtlb_entry(tlb_entry);
}

/*
 * DO NOT USE THESE FUNCTIONS.  These instructions aren't part of the Xtensa
 * ISA and exist only for test purposes..
 * You may find it helpful for MMU debugging, however.
 *
 * 'at' is the unmodified input register
 * 'as' is the output register, as follows (specific to the Linux config):
 *
 *      as[31..12] contain the virtual address
 *      as[11..08] are meaningless
 *      as[07..00] contain the asid
 */

static inline unsigned long read_dtlb_virtual (int way)
{
	unsigned long tmp;
	__asm__ __volatile__("rdtlb0  %0, %1\n\t" : "=a" (tmp), "+a" (way));
	return tmp;
}

static inline unsigned long read_dtlb_translation (int way)
{
	unsigned long tmp;
	__asm__ __volatile__("rdtlb1  %0, %1\n\t" : "=a" (tmp), "+a" (way));
	return tmp;
}

static inline unsigned long read_itlb_virtual (int way)
{
	unsigned long tmp;
	__asm__ __volatile__("ritlb0  %0, %1\n\t" : "=a" (tmp), "+a" (way));
	return tmp;
}

static inline unsigned long read_itlb_translation (int way)
{
	unsigned long tmp;
	__asm__ __volatile__("ritlb1  %0, %1\n\t" : "=a" (tmp), "+a" (way));
	return tmp;
}

#endif	/* __ASSEMBLY__ */
#endif	/* _XTENSA_TLBFLUSH_H */