tlb.c

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/*
 * Copyright (C) 2006 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * TLB management.
 */

#include <mm/tlb.h>
#include <mm/asid.h>
#include <mm/page.h>
#include <mm/as.h>
#include <arch/mm/tlb.h>
#include <arch/mm/page.h>
#include <arch/mm/vhpt.h>
#include <arch/barrier.h>
#include <arch/interrupt.h>
#include <arch/pal/pal.h>
#include <arch/asm.h>
#include <typedefs.h>
#include <panic.h>
#include <print.h>
#include <arch.h>
#include <interrupt.h>

void tlb_invalidate_all(void)
{
                ipl_t ipl;
                __address adr;
                __u32 count1, count2, stride1, stride2;
                
                int i,j;
                
                adr = PAL_PTCE_INFO_BASE();
                count1 = PAL_PTCE_INFO_COUNT1();
                count2 = PAL_PTCE_INFO_COUNT2();
                stride1 = PAL_PTCE_INFO_STRIDE1();
                stride2 = PAL_PTCE_INFO_STRIDE2();
                
                ipl = interrupts_disable();

                for(i = 0; i < count1; i++) {
                        for(j = 0; j < count2; j++) {
                                __asm__ volatile (
                                        "ptc.e %0 ;;"
                                        :
                                        : "r" (adr)
                                );
                                adr += stride2;
                        }
                        adr += stride1;
                }

                interrupts_restore(ipl);

                srlz_d();
                srlz_i();
#ifdef CONFIG_VHPT
                vhpt_invalidate_all();
#endif  
}

void tlb_invalidate_asid(asid_t asid)
{
        tlb_invalidate_all();
}


void tlb_invalidate_pages(asid_t asid, __address page, count_t cnt)
{
        region_register rr;
        bool restore_rr = false;
        int b = 0;
        int c = cnt;

        __address va;
        va = page;

        rr.word = rr_read(VA2VRN(va));
        if ((restore_rr = (rr.map.rid != ASID2RID(asid, VA2VRN(va))))) {
                /*
                 * The selected region register does not contain required RID.
                 * Save the old content of the register and replace the RID.
                 */
                region_register rr0;

                rr0 = rr;
                rr0.map.rid = ASID2RID(asid, VA2VRN(va));
                rr_write(VA2VRN(va), rr0.word);
                srlz_d();
                srlz_i();
        }
        
        while(c >>= 1)
                b++;
        b >>= 1;
        __u64 ps;
        
        switch (b) {
                case 0: /*cnt 1-3*/
                        ps = PAGE_WIDTH;
                        break;
                case 1: /*cnt 4-15*/
                        /*cnt=((cnt-1)/4)+1;*/
                        ps = PAGE_WIDTH+2;
                        va &= ~((1<<ps)-1);
                        break;
                case 2: /*cnt 16-63*/
                        /*cnt=((cnt-1)/16)+1;*/
                        ps = PAGE_WIDTH+4;
                        va &= ~((1<<ps)-1);
                        break;
                case 3: /*cnt 64-255*/
                        /*cnt=((cnt-1)/64)+1;*/
                        ps = PAGE_WIDTH+6;
                        va &= ~((1<<ps)-1);
                        break;
                case 4: /*cnt 256-1023*/
                        /*cnt=((cnt-1)/256)+1;*/
                        ps = PAGE_WIDTH+8;
                        va &= ~((1<<ps)-1);
                        break;
                case 5: /*cnt 1024-4095*/
                        /*cnt=((cnt-1)/1024)+1;*/
                        ps = PAGE_WIDTH+10;
                        va &= ~((1<<ps)-1);
                        break;
                case 6: /*cnt 4096-16383*/
                        /*cnt=((cnt-1)/4096)+1;*/
                        ps = PAGE_WIDTH+12;
                        va &= ~((1<<ps)-1);
                        break;
                case 7: /*cnt 16384-65535*/
                case 8: /*cnt 65536-(256K-1)*/
                        /*cnt=((cnt-1)/16384)+1;*/
                        ps = PAGE_WIDTH+14;
                        va &= ~((1<<ps)-1);
                        break;
                default:
                        /*cnt=((cnt-1)/(16384*16))+1;*/
                        ps=PAGE_WIDTH+18;
                        va&=~((1<<ps)-1);
                        break;
        }
        /*cnt+=(page!=va);*/
        for(; va<(page+cnt*(PAGE_SIZE)); va += (1<<ps)) {
                __asm__ volatile (
                        "ptc.l %0,%1;;"
                        :
                        : "r" (va), "r" (ps<<2)
                );
        }
        srlz_d();
        srlz_i();
        
        if (restore_rr) {
                rr_write(VA2VRN(va), rr.word);
                srlz_d();
                srlz_i();
        }
}

void dtc_mapping_insert(__address va, asid_t asid, tlb_entry_t entry)
{
        tc_mapping_insert(va, asid, entry, true);
}

void itc_mapping_insert(__address va, asid_t asid, tlb_entry_t entry)
{
        tc_mapping_insert(va, asid, entry, false);
}

void tc_mapping_insert(__address va, asid_t asid, tlb_entry_t entry, bool dtc)
{
        region_register rr;
        bool restore_rr = false;

        rr.word = rr_read(VA2VRN(va));
        if ((restore_rr = (rr.map.rid != ASID2RID(asid, VA2VRN(va))))) {
                /*
                 * The selected region register does not contain required RID.
                 * Save the old content of the register and replace the RID.
                 */
                region_register rr0;

                rr0 = rr;
                rr0.map.rid = ASID2RID(asid, VA2VRN(va));
                rr_write(VA2VRN(va), rr0.word);
                srlz_d();
                srlz_i();
        }
        
        __asm__ volatile (
                "mov r8=psr;;\n"
                "rsm %0;;\n"                    /* PSR_IC_MASK */
                "srlz.d;;\n"
                "srlz.i;;\n"
                "mov cr.ifa=%1\n"               /* va */
                "mov cr.itir=%2;;\n"            /* entry.word[1] */
                "cmp.eq p6,p7 = %4,r0;;\n"      /* decide between itc and dtc */ 
                "(p6) itc.i %3;;\n"
                "(p7) itc.d %3;;\n"
                "mov psr.l=r8;;\n"
                "srlz.d;;\n"
                :
                : "i" (PSR_IC_MASK), "r" (va), "r" (entry.word[1]), "r" (entry.word[0]), "r" (dtc)
                : "p6", "p7", "r8"
        );
        
        if (restore_rr) {
                rr_write(VA2VRN(va), rr.word);
                srlz_d();
                srlz_i();
        }
}

void itr_mapping_insert(__address va, asid_t asid, tlb_entry_t entry, index_t tr)
{
        tr_mapping_insert(va, asid, entry, false, tr);
}

void dtr_mapping_insert(__address va, asid_t asid, tlb_entry_t entry, index_t tr)
{
        tr_mapping_insert(va, asid, entry, true, tr);
}

void tr_mapping_insert(__address va, asid_t asid, tlb_entry_t entry, bool dtr, index_t tr)
{
        region_register rr;
        bool restore_rr = false;

        rr.word = rr_read(VA2VRN(va));
        if ((restore_rr = (rr.map.rid != ASID2RID(asid, VA2VRN(va))))) {
                /*
                 * The selected region register does not contain required RID.
                 * Save the old content of the register and replace the RID.
                 */
                region_register rr0;

                rr0 = rr;
                rr0.map.rid = ASID2RID(asid, VA2VRN(va));
                rr_write(VA2VRN(va), rr0.word);
                srlz_d();
                srlz_i();
        }

        __asm__ volatile (
                "mov r8=psr;;\n"
                "rsm %0;;\n"                    /* PSR_IC_MASK */
                "srlz.d;;\n"
                "srlz.i;;\n"
                "mov cr.ifa=%1\n"               /* va */                 
                "mov cr.itir=%2;;\n"            /* entry.word[1] */ 
                "cmp.eq p6,p7=%5,r0;;\n"        /* decide between itr and dtr */
                "(p6) itr.i itr[%4]=%3;;\n"
                "(p7) itr.d dtr[%4]=%3;;\n"
                "mov psr.l=r8;;\n"
                "srlz.d;;\n"
                :
                : "i" (PSR_IC_MASK), "r" (va), "r" (entry.word[1]), "r" (entry.word[0]), "r" (tr), "r" (dtr)
                : "p6", "p7", "r8"
        );
        
        if (restore_rr) {
                rr_write(VA2VRN(va), rr.word);
                srlz_d();
                srlz_i();
        }
}

void dtlb_kernel_mapping_insert(__address page, __address frame, bool dtr, index_t tr)
{
        tlb_entry_t entry;
        
        entry.word[0] = 0;
        entry.word[1] = 0;
        
        entry.p = true;                 /* present */
        entry.ma = MA_WRITEBACK;
        entry.a = true;                 /* already accessed */
        entry.d = true;                 /* already dirty */
        entry.pl = PL_KERNEL;
        entry.ar = AR_READ | AR_WRITE;
        entry.ppn = frame >> PPN_SHIFT;
        entry.ps = PAGE_WIDTH;
        
        if (dtr)
                dtr_mapping_insert(page, ASID_KERNEL, entry, tr);
        else
                dtc_mapping_insert(page, ASID_KERNEL, entry);
}

void dtr_purge(__address page, count_t width)
{
        __asm__ volatile ("ptr.d %0, %1\n" : : "r" (page), "r" (width<<2));
}


void dtc_pte_copy(pte_t *t)
{
        tlb_entry_t entry;

        entry.word[0] = 0;
        entry.word[1] = 0;
        
        entry.p = t->p;
        entry.ma = t->c ? MA_WRITEBACK : MA_UNCACHEABLE;
        entry.a = t->a;
        entry.d = t->d;
        entry.pl = t->k ? PL_KERNEL : PL_USER;
        entry.ar = t->w ? AR_WRITE : AR_READ;
        entry.ppn = t->frame >> PPN_SHIFT;
        entry.ps = PAGE_WIDTH;
        
        dtc_mapping_insert(t->page, t->as->asid, entry);
#ifdef CONFIG_VHPT
        vhpt_mapping_insert(t->page, t->as->asid, entry);
#endif  
}

void itc_pte_copy(pte_t *t)
{
        tlb_entry_t entry;

        entry.word[0] = 0;
        entry.word[1] = 0;
        
        ASSERT(t->x);
        
        entry.p = t->p;
        entry.ma = t->c ? MA_WRITEBACK : MA_UNCACHEABLE;
        entry.a = t->a;
        entry.pl = t->k ? PL_KERNEL : PL_USER;
        entry.ar = t->x ? (AR_EXECUTE | AR_READ) : AR_READ;
        entry.ppn = t->frame >> PPN_SHIFT;
        entry.ps = PAGE_WIDTH;
        
        itc_mapping_insert(t->page, t->as->asid, entry);
#ifdef CONFIG_VHPT
        vhpt_mapping_insert(t->page, t->as->asid, entry);
#endif  
}

void alternate_instruction_tlb_fault(__u64 vector, istate_t *istate)
{
        region_register rr;
        rid_t rid;
        __address va;
        pte_t *t;
        
        va = istate->cr_ifa;    /* faulting address */
        rr.word = rr_read(VA2VRN(va));
        rid = rr.map.rid;

        page_table_lock(AS, true);
        t = page_mapping_find(AS, va);
        if (t) {
                /*
                 * The mapping was found in software page hash table.
                 * Insert it into data translation cache.
                 */
                itc_pte_copy(t);
                page_table_unlock(AS, true);
        } else {
                /*
                 * Forward the page fault to address space page fault handler.
                 */
                page_table_unlock(AS, true);
                if (as_page_fault(va, PF_ACCESS_EXEC, istate) == AS_PF_FAULT) {
                        fault_if_from_uspace(istate,"Page fault at %p",va);
                        panic("%s: va=%p, rid=%d, iip=%p\n", __FUNCTION__, va, rid, istate->cr_iip);
                }
        }
}

void alternate_data_tlb_fault(__u64 vector, istate_t *istate)
{
        region_register rr;
        rid_t rid;
        __address va;
        pte_t *t;
        
        va = istate->cr_ifa;    /* faulting address */
        rr.word = rr_read(VA2VRN(va));
        rid = rr.map.rid;
        if (RID2ASID(rid) == ASID_KERNEL) {
                if (VA2VRN(va) == VRN_KERNEL) {
                        /*
                         * Provide KA2PA(identity) mapping for faulting piece of
                         * kernel address space.
                         */
                        dtlb_kernel_mapping_insert(va, KA2PA(va), false, 0);
                        return;
                }
        }

        page_table_lock(AS, true);
        t = page_mapping_find(AS, va);
        if (t) {
                /*
                 * The mapping was found in software page hash table.
                 * Insert it into data translation cache.
                 */
                dtc_pte_copy(t);
                page_table_unlock(AS, true);
        } else {
                /*
                 * Forward the page fault to address space page fault handler.
                 */
                page_table_unlock(AS, true);
                if (as_page_fault(va, PF_ACCESS_READ, istate) == AS_PF_FAULT) {
                        fault_if_from_uspace(istate,"Page fault at %p",va);
                        panic("%s: va=%p, rid=%d, iip=%p\n", __FUNCTION__, va, rid, istate->cr_iip);
                }
        }
}

void data_nested_tlb_fault(__u64 vector, istate_t *istate)
{
        panic("%s\n", __FUNCTION__);
}

void data_dirty_bit_fault(__u64 vector, istate_t *istate)
{
        region_register rr;
        rid_t rid;
        __address va;
        pte_t *t;
        
        va = istate->cr_ifa;    /* faulting address */
        rr.word = rr_read(VA2VRN(va));
        rid = rr.map.rid;

        page_table_lock(AS, true);
        t = page_mapping_find(AS, va);
        ASSERT(t && t->p);
        if (t && t->p && t->w) {
                /*
                 * Update the Dirty bit in page tables and reinsert
                 * the mapping into DTC.
                 */
                t->d = true;
                dtc_pte_copy(t);
        } else {
                if (as_page_fault(va, PF_ACCESS_WRITE, istate) == AS_PF_FAULT) {
                        fault_if_from_uspace(istate,"Page fault at %p",va);
                        panic("%s: va=%p, rid=%d, iip=%p\n", __FUNCTION__, va, rid, istate->cr_iip);
                        t->d = true;
                        dtc_pte_copy(t);
                }
        }
        page_table_unlock(AS, true);
}

void instruction_access_bit_fault(__u64 vector, istate_t *istate)
{
        region_register rr;
        rid_t rid;
        __address va;
        pte_t *t;       

        va = istate->cr_ifa;    /* faulting address */
        rr.word = rr_read(VA2VRN(va));
        rid = rr.map.rid;

        page_table_lock(AS, true);
        t = page_mapping_find(AS, va);
        ASSERT(t && t->p);
        if (t && t->p && t->x) {
                /*
                 * Update the Accessed bit in page tables and reinsert
                 * the mapping into ITC.
                 */
                t->a = true;
                itc_pte_copy(t);
        } else {
                if (as_page_fault(va, PF_ACCESS_EXEC, istate) == AS_PF_FAULT) {
                        fault_if_from_uspace(istate,"Page fault at %p",va);
                        panic("%s: va=%p, rid=%d, iip=%p\n", __FUNCTION__, va, rid, istate->cr_iip);
                        t->a = true;
                        itc_pte_copy(t);
                }
        }
        page_table_unlock(AS, true);
}

void data_access_bit_fault(__u64 vector, istate_t *istate)
{
        region_register rr;
        rid_t rid;
        __address va;
        pte_t *t;

        va = istate->cr_ifa;    /* faulting address */
        rr.word = rr_read(VA2VRN(va));
        rid = rr.map.rid;

        page_table_lock(AS, true);
        t = page_mapping_find(AS, va);
        ASSERT(t && t->p);
        if (t && t->p) {
                /*
                 * Update the Accessed bit in page tables and reinsert
                 * the mapping into DTC.
                 */
                t->a = true;
                dtc_pte_copy(t);
        } else {
                if (as_page_fault(va, PF_ACCESS_READ, istate) == AS_PF_FAULT) {
                        fault_if_from_uspace(istate,"Page fault at %p",va);
                        panic("%s: va=%p, rid=%d, iip=%p\n", __FUNCTION__, va, rid, istate->cr_iip);
                        t->a = true;
                        itc_pte_copy(t);
                }
        }
        page_table_unlock(AS, true);
}

void page_not_present(__u64 vector, istate_t *istate)
{
        region_register rr;
        rid_t rid;
        __address va;
        pte_t *t;
        
        va = istate->cr_ifa;    /* faulting address */
        rr.word = rr_read(VA2VRN(va));
        rid = rr.map.rid;

        page_table_lock(AS, true);
        t = page_mapping_find(AS, va);
        ASSERT(t);
        
        if (t->p) {
                /*
                 * If the Present bit is set in page hash table, just copy it
                 * and update ITC/DTC.
                 */
                if (t->x)
                        itc_pte_copy(t);
                else
                        dtc_pte_copy(t);
                page_table_unlock(AS, true);
        } else {
                page_table_unlock(AS, true);
                if (as_page_fault(va, PF_ACCESS_READ, istate) == AS_PF_FAULT) {
                        fault_if_from_uspace(istate,"Page fault at %p",va);
                        panic("%s: va=%p, rid=%d\n", __FUNCTION__, va, rid);
                }
        }
}

---