Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  linux/arch/or32/mm/tlb.c

 *

 *  or32 version

 *    author(s): Matjaz Breskvar (phoenix@bsemi.com)

 *

 *  derived from cris, i386, m68k, ppc, sh ports.

 *

 *  changes:

 *  18. 11. 2003: Matjaz Breskvar (phoenix@bsemi.com)

 *    initial port to or32 architecture

 *

 *  based on: linux/arch/cris/mm/tlb.c

 *    Copyright (C) 2000, 2001  Axis Communications AB

 *    Authors:   Bjorn Wesen (bjornw@axis.com)

 *

 */

#include <linux/sched.h>

#include <linux/kernel.h>

#include <linux/errno.h>

#include <linux/string.h>

#include <linux/types.h>

#include <linux/ptrace.h>

#include <linux/mman.h>

#include <linux/mm.h>

#include <linux/init.h>

#include <asm/system.h>

#include <asm/segment.h>

#include <asm/tlbflush.h>

#include <asm/pgtable.h>

#include <asm/mmu_context.h>

#include <asm/or32-hf.h>

#include <asm/spr_defs.h>

#define D(x)

#define NUM_TLB_ENTRIES 64

#define TLB_OFFSET(add) (((add) >> PAGE_SHIFT) & (NUM_TLB_ENTRIES-1))

#define NO_CONTEXT -1

/* this is to work around for certian problems */

#define CONFIG_OR32_FLUSH_ALL

#define or32_disable_immu()                \

{                                          \

        unsigned long __t1, __t2;          \

        __asm__ __volatile__(              \

                "l.movhi  %6,hi(99f)    ;" \

                "l.ori    %6,%6,lo(99f) ;" \

                "l.movhi  %0,%5         ;" \

                "l.add    %0,%0,%6      ;" \

                "l.mtspr  r0,%0,%1      ;" \

                "l.mfspr  %0,r0,%2      ;" \

                "l.andi   %0,%0,lo(%3)  ;" \

                "l.mtspr  r0,%0,%4      ;" \

                "l.rfe   ;l.nop;l.nop;l.nop;l.nop;l.nop               ;" \

                "99:                     " \

                : "=r"(__t1)               \

                : "K"(SPR_EPCR_BASE), "K"(SPR_SR),        \

                  "K"(0x0000ffff&(~(SPR_SR_IME))), "K"(SPR_ESR_BASE), \

                  "K"((-KERNELBASE)>>16), "r"(__t2)); \

}

#define or32_enable_immu()            \

{                                     \

        unsigned long __t1;                \

        __asm__ __volatile__(         \

                "l.movhi  %0,hi(99f);" \

                "l.ori    %0,%0,lo(99f);" \

                "l.mtspr  r0,%0,%1  ;" \

                "l.mfspr  %0,r0,%2  ;" \

                "l.ori    %0,%0,lo(%3) ;" \

                "l.mtspr  r0,%0,%4  ;" \

                "l.rfe              ;" \

                "l.nop;l.nop;l.nop;l.nop;" \

                "99:                " \

                : "=r"(__t1)     \

                : "K"(SPR_EPCR_BASE), "K"(SPR_SR),         \

                  "K"(SPR_SR_IME), "K"(SPR_ESR_BASE));     \

}

/* invalidate all TLB entries */

void flush_tlb_all(void)

{

        int i;

        unsigned long flags;

        D(printk("tlb: flushed all\n"));

        local_irq_save(flags); /* flush needs to be atomic */

//      or32_disable_immu();

        for(i = 0; i < NUM_TLB_ENTRIES; i++) {

                mtspr(SPR_DTLBMR_BASE(0) + i, 0);

                mtspr(SPR_ITLBMR_BASE(0) + i, 0);

        }

//      or32_enable_immu();

        local_irq_restore(flags);

}

/* invalidate the selected mm context only */

void flush_tlb_mm(struct mm_struct *mm)

{

#ifdef CONFIG_OR32_FLUSH_ALL

        flush_tlb_all();

#else

        D(printk("tlb: flush mm (%p)\n", mm));

        if(mm->map_count) {

                struct vm_area_struct *mp;

                for(mp = mm->mmap; mp != NULL; mp = mp->vm_next)

                        flush_tlb_range(mp, mp->vm_start,  mp->vm_end);

        }

#endif

}

/* invalidate a single page */

void flush_tlb_page(struct vm_area_struct *vma,

                    unsigned long addr)

{

#ifdef CONFIG_OR32_FLUSH_ALL

        flush_tlb_all();

#else

        unsigned long tlb_offset, flags;

        D(printk("tlb: flush page %p \n", addr));

        addr &= PAGE_MASK; /* perhaps not necessary */

        tlb_offset = TLB_OFFSET(addr);

        local_irq_save(flags);  /* flush needs to be atomic */

        if((mfspr(SPR_DTLBMR_BASE(0) + tlb_offset) & PAGE_MASK) == addr)

                mtspr(SPR_DTLBMR_BASE(0) + tlb_offset, 0);

        if((mfspr(SPR_ITLBMR_BASE(0) + tlb_offset) & PAGE_MASK) == addr)

                mtspr(SPR_ITLBMR_BASE(0) + tlb_offset, 0);

        local_irq_restore(flags);

#endif

}

/* invalidate a page range */

void flush_tlb_range(struct vm_area_struct *vma,

                     unsigned long start,

                     unsigned long end)

{

#ifdef CONFIG_OR32_FLUSH_ALL

        flush_tlb_all();

#else

        unsigned long vpn, flags;

        D(printk("tlb: flush range %p<->%p (%p)\n",

                 start, end, vma));

        start = start >> PAGE_SHIFT;

        end   = end   >> PAGE_SHIFT;

        local_irq_save(flags);  /* flush needs to be atomic */

        for (vpn = start; vpn < end; vpn++) {

                unsigned long slot = vpn%NUM_TLB_ENTRIES;

                if (vpn == (mfspr(SPR_DTLBMR_BASE(0) + slot) >> PAGE_SHIFT)) {

                        mtspr(SPR_DTLBMR_BASE(0) + slot,0);

                        D(printk("DTLB invalidate :: vpn 0x%x, set %d\n", vpn, slot));

                }

                if (vpn == (mfspr(SPR_ITLBMR_BASE(0) + slot) >> PAGE_SHIFT)) {

                        mtspr(SPR_ITLBMR_BASE(0) + slot,0);

                        D(printk("ITLB invalidate :: vpn 0x%x, set %d\n", vpn, slot));

                }

        }

        local_irq_restore(flags);

#endif

}

/* called in schedule() just before actually doing the switch_to */

void switch_mm(struct mm_struct *prev, struct mm_struct *next,

               struct task_struct *next_tsk)

{

        /* remember the pgd for the fault handlers

         * this is similar to the pgd register in some other CPU's.

         * we need our own copy of it because current and active_mm

         * might be invalid at points where we still need to derefer

         * the pgd.

         */

        current_pgd = next->pgd;

        /* We don't have context support implemented, so flush all

         * entries belonging to previous map

         */

/*

        phx_mmu("prev_mm %p, next_mm %p, next_tsk %p, "

                "next_tsk->mm %p, current %p",

                prev, next, next_tsk, next_tsk ? next_tsk->mm : 0, current);

*/

#ifdef CONFIG_OR32_FLUSH_ALL

        flush_tlb_all();

#else

        if (prev != next)

                flush_tlb_mm(prev);

#endif

}

/*

 * Initialize the context related info for a new mm_struct

 * instance.

 */

int init_new_context(struct task_struct *tsk, struct mm_struct *mm)

{

        mm->context = NO_CONTEXT;

        return 0;

}

/* called by __exit_mm to destroy the used MMU context if any before

 * destroying the mm itself. this is only called when the last user of the mm

 * drops it.

 */

void destroy_context(struct mm_struct *mm)

{

        D(printk("destroy_context %d (%p)\n", mm->context, mm));

#ifdef CONFIG_OR32_FLUSH_ALL

        flush_tlb_all();

#else

        flush_tlb_mm(mm);

#endif

}

/* called once during VM initialization, from init.c */

void __init tlb_init(void)

{

        /* invalidate the entire TLB */

        flush_tlb_all();

}