source: mainline/kernel/arch/sparc64/src/mm/sun4u/tlb.c@ 96b02eb9

/*
 * Copyright (c) 2005 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.
 */

/** @addtogroup sparc64mm
 * @{
 */
/** @file
 */

#include <arch/mm/tlb.h>
#include <mm/tlb.h>
#include <mm/as.h>
#include <mm/asid.h>
#include <arch/mm/frame.h>
#include <arch/mm/page.h>
#include <arch/mm/mmu.h>
#include <arch/interrupt.h>
#include <interrupt.h>
#include <arch.h>
#include <print.h>
#include <typedefs.h>
#include <config.h>
#include <arch/trap/trap.h>
#include <arch/trap/exception.h>
#include <panic.h>
#include <arch/asm.h>
#include <genarch/mm/page_ht.h>

#ifdef CONFIG_TSB
#include <arch/mm/tsb.h>
#endif

static void dtlb_pte_copy(pte_t *, size_t, bool);
static void itlb_pte_copy(pte_t *, size_t);
static void do_fast_instruction_access_mmu_miss_fault(istate_t *, uintptr_t,
    const char *);
static void do_fast_data_access_mmu_miss_fault(istate_t *, tlb_tag_access_reg_t,
    const char *);
static void do_fast_data_access_protection_fault(istate_t *,
    tlb_tag_access_reg_t, const char *);

const char *context_encoding[] = {
        "Primary",
        "Secondary",
        "Nucleus",
        "Reserved"
};

void tlb_arch_init(void)
{
        /*
         * Invalidate all non-locked DTLB and ITLB entries.
         */
        tlb_invalidate_all();

        /*
         * Clear both SFSRs.
         */
        dtlb_sfsr_write(0);
        itlb_sfsr_write(0);
}

/** Insert privileged mapping into DMMU TLB.
 *
 * @param page          Virtual page address.
 * @param frame         Physical frame address.
 * @param pagesize      Page size.
 * @param locked        True for permanent mappings, false otherwise.
 * @param cacheable     True if the mapping is cacheable, false otherwise.
 */
void dtlb_insert_mapping(uintptr_t page, uintptr_t frame, int pagesize,
    bool locked, bool cacheable)
{
        tlb_tag_access_reg_t tag;
        tlb_data_t data;
        page_address_t pg;
        frame_address_t fr;

        pg.address = page;
        fr.address = frame;

        tag.context = ASID_KERNEL;
        tag.vpn = pg.vpn;

        dtlb_tag_access_write(tag.value);

        data.value = 0;
        data.v = true;
        data.size = pagesize;
        data.pfn = fr.pfn;
        data.l = locked;
        data.cp = cacheable;
#ifdef CONFIG_VIRT_IDX_DCACHE
        data.cv = cacheable;
#endif /* CONFIG_VIRT_IDX_DCACHE */
        data.p = true;
        data.w = true;
        data.g = false;

        dtlb_data_in_write(data.value);
}

/** Copy PTE to TLB.
 *
 * @param t             Page Table Entry to be copied.
 * @param index         Zero if lower 8K-subpage, one if higher 8K-subpage.
 * @param ro            If true, the entry will be created read-only, regardless
 *                      of its w field.
 */
void dtlb_pte_copy(pte_t *t, size_t index, bool ro)
{
        tlb_tag_access_reg_t tag;
        tlb_data_t data;
        page_address_t pg;
        frame_address_t fr;

        pg.address = t->page + (index << MMU_PAGE_WIDTH);
        fr.address = t->frame + (index << MMU_PAGE_WIDTH);

        tag.value = 0;
        tag.context = t->as->asid;
        tag.vpn = pg.vpn;

        dtlb_tag_access_write(tag.value);

        data.value = 0;
        data.v = true;
        data.size = PAGESIZE_8K;
        data.pfn = fr.pfn;
        data.l = false;
        data.cp = t->c;
#ifdef CONFIG_VIRT_IDX_DCACHE
        data.cv = t->c;
#endif /* CONFIG_VIRT_IDX_DCACHE */
        data.p = t->k;          /* p like privileged */
        data.w = ro ? false : t->w;
        data.g = t->g;

        dtlb_data_in_write(data.value);
}

/** Copy PTE to ITLB.
 *
 * @param t             Page Table Entry to be copied.
 * @param index         Zero if lower 8K-subpage, one if higher 8K-subpage.
 */
void itlb_pte_copy(pte_t *t, size_t index)
{
        tlb_tag_access_reg_t tag;
        tlb_data_t data;
        page_address_t pg;
        frame_address_t fr;

        pg.address = t->page + (index << MMU_PAGE_WIDTH);
        fr.address = t->frame + (index << MMU_PAGE_WIDTH);

        tag.value = 0;
        tag.context = t->as->asid;
        tag.vpn = pg.vpn;
        
        itlb_tag_access_write(tag.value);
        
        data.value = 0;
        data.v = true;
        data.size = PAGESIZE_8K;
        data.pfn = fr.pfn;
        data.l = false;
        data.cp = t->c;
        data.p = t->k;          /* p like privileged */
        data.w = false;
        data.g = t->g;
        
        itlb_data_in_write(data.value);
}

/** ITLB miss handler. */
void fast_instruction_access_mmu_miss(sysarg_t unused, istate_t *istate)
{
        uintptr_t page_16k = ALIGN_DOWN(istate->tpc, PAGE_SIZE);
        size_t index = (istate->tpc >> MMU_PAGE_WIDTH) % MMU_PAGES_PER_PAGE;
        pte_t *t;

        page_table_lock(AS, true);
        t = page_mapping_find(AS, page_16k);
        if (t && PTE_EXECUTABLE(t)) {
                /*
                 * The mapping was found in the software page hash table.
                 * Insert it into ITLB.
                 */
                t->a = true;
                itlb_pte_copy(t, index);
#ifdef CONFIG_TSB
                itsb_pte_copy(t, index);
#endif
                page_table_unlock(AS, true);
        } else {
                /*
                 * Forward the page fault to the address space page fault
                 * handler.
                 */
                page_table_unlock(AS, true);
                if (as_page_fault(page_16k, PF_ACCESS_EXEC, istate) ==
                    AS_PF_FAULT) {
                        do_fast_instruction_access_mmu_miss_fault(istate,
                            istate->tpc, __func__);
                }
        }
}

/** DTLB miss handler.
 *
 * Note that some faults (e.g. kernel faults) were already resolved by the
 * low-level, assembly language part of the fast_data_access_mmu_miss handler.
 *
 * @param tag           Content of the TLB Tag Access register as it existed
 *                      when the trap happened. This is to prevent confusion
 *                      created by clobbered Tag Access register during a nested
 *                      DTLB miss.
 * @param istate        Interrupted state saved on the stack.
 */
void fast_data_access_mmu_miss(tlb_tag_access_reg_t tag, istate_t *istate)
{
        uintptr_t page_8k;
        uintptr_t page_16k;
        size_t index;
        pte_t *t;

        page_8k = (uint64_t) tag.vpn << MMU_PAGE_WIDTH;
        page_16k = ALIGN_DOWN(page_8k, PAGE_SIZE);
        index = tag.vpn % MMU_PAGES_PER_PAGE;

        if (tag.context == ASID_KERNEL) {
                if (!tag.vpn) {
                        /* NULL access in kernel */
                        do_fast_data_access_mmu_miss_fault(istate, tag,
                            "Dereferencing NULL pointer.");
                } else if (page_8k >= end_of_identity) {
                        /*
                         * The kernel is accessing the I/O space.
                         * We still do identity mapping for I/O,
                         * but without caching.
                         */
                        dtlb_insert_mapping(page_8k, KA2PA(page_8k),
                            PAGESIZE_8K, false, false);
                        return;
                }
                do_fast_data_access_mmu_miss_fault(istate, tag, "Unexpected "
                    "kernel page fault.");
        }

        page_table_lock(AS, true);
        t = page_mapping_find(AS, page_16k);
        if (t) {
                /*
                 * The mapping was found in the software page hash table.
                 * Insert it into DTLB.
                 */
                t->a = true;
                dtlb_pte_copy(t, index, true);
#ifdef CONFIG_TSB
                dtsb_pte_copy(t, index, true);
#endif
                page_table_unlock(AS, true);
        } else {
                /*
                 * Forward the page fault to the address space page fault
                 * handler.
                 */             
                page_table_unlock(AS, true);
                if (as_page_fault(page_16k, PF_ACCESS_READ, istate) ==
                    AS_PF_FAULT) {
                        do_fast_data_access_mmu_miss_fault(istate, tag,
                            __func__);
                }
        }
}

/** DTLB protection fault handler.
 *
 * @param tag           Content of the TLB Tag Access register as it existed
 *                      when the trap happened. This is to prevent confusion
 *                      created by clobbered Tag Access register during a nested
 *                      DTLB miss.
 * @param istate        Interrupted state saved on the stack.
 */
void fast_data_access_protection(tlb_tag_access_reg_t tag, istate_t *istate)
{
        uintptr_t page_16k;
        size_t index;
        pte_t *t;

        page_16k = ALIGN_DOWN((uint64_t) tag.vpn << MMU_PAGE_WIDTH, PAGE_SIZE);
        index = tag.vpn % MMU_PAGES_PER_PAGE;   /* 16K-page emulation */

        page_table_lock(AS, true);
        t = page_mapping_find(AS, page_16k);
        if (t && PTE_WRITABLE(t)) {
                /*
                 * The mapping was found in the software page hash table and is
                 * writable. Demap the old mapping and insert an updated mapping
                 * into DTLB.
                 */
                t->a = true;
                t->d = true;
                dtlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_SECONDARY,
                    page_16k + index * MMU_PAGE_SIZE);
                dtlb_pte_copy(t, index, false);
#ifdef CONFIG_TSB
                dtsb_pte_copy(t, index, false);
#endif
                page_table_unlock(AS, true);
        } else {
                /*
                 * Forward the page fault to the address space page fault
                 * handler.
                 */             
                page_table_unlock(AS, true);
                if (as_page_fault(page_16k, PF_ACCESS_WRITE, istate) ==
                    AS_PF_FAULT) {
                        do_fast_data_access_protection_fault(istate, tag,
                            __func__);
                }
        }
}

/** Print TLB entry (for debugging purposes).
 *
 * The diag field has been left out in order to make this function more generic
 * (there is no diag field in US3 architeture). 
 *
 * @param i             TLB entry number 
 * @param t             TLB entry tag
 * @param d             TLB entry data 
 */
static void print_tlb_entry(int i, tlb_tag_read_reg_t t, tlb_data_t d)
{
        printf("%u: vpn=%#" PRIx64 ", context=%u, v=%u, size=%u, nfo=%u, "
            "ie=%u, soft2=%#x, pfn=%#x, soft=%#x, l=%u, "
            "cp=%u, cv=%u, e=%u, p=%u, w=%u, g=%u\n", i, (uint64_t) t.vpn,
            t.context, d.v, d.size, d.nfo, d.ie, d.soft2,
            d.pfn, d.soft, d.l, d.cp, d.cv, d.e, d.p, d.w, d.g);
}

#if defined (US)

/** Print contents of both TLBs. */
void tlb_print(void)
{
        int i;
        tlb_data_t d;
        tlb_tag_read_reg_t t;
        
        printf("I-TLB contents:\n");
        for (i = 0; i < ITLB_ENTRY_COUNT; i++) {
                d.value = itlb_data_access_read(i);
                t.value = itlb_tag_read_read(i);
                print_tlb_entry(i, t, d);
        }

        printf("D-TLB contents:\n");
        for (i = 0; i < DTLB_ENTRY_COUNT; i++) {
                d.value = dtlb_data_access_read(i);
                t.value = dtlb_tag_read_read(i);
                print_tlb_entry(i, t, d);
        }
}

#elif defined (US3)

/** Print contents of all TLBs. */
void tlb_print(void)
{
        int i;
        tlb_data_t d;
        tlb_tag_read_reg_t t;
        
        printf("TLB_ISMALL contents:\n");
        for (i = 0; i < tlb_ismall_size(); i++) {
                d.value = dtlb_data_access_read(TLB_ISMALL, i);
                t.value = dtlb_tag_read_read(TLB_ISMALL, i);
                print_tlb_entry(i, t, d);
        }
        
        printf("TLB_IBIG contents:\n");
        for (i = 0; i < tlb_ibig_size(); i++) {
                d.value = dtlb_data_access_read(TLB_IBIG, i);
                t.value = dtlb_tag_read_read(TLB_IBIG, i);
                print_tlb_entry(i, t, d);
        }
        
        printf("TLB_DSMALL contents:\n");
        for (i = 0; i < tlb_dsmall_size(); i++) {
                d.value = dtlb_data_access_read(TLB_DSMALL, i);
                t.value = dtlb_tag_read_read(TLB_DSMALL, i);
                print_tlb_entry(i, t, d);
        }
        
        printf("TLB_DBIG_1 contents:\n");
        for (i = 0; i < tlb_dbig_size(); i++) {
                d.value = dtlb_data_access_read(TLB_DBIG_0, i);
                t.value = dtlb_tag_read_read(TLB_DBIG_0, i);
                print_tlb_entry(i, t, d);
        }
        
        printf("TLB_DBIG_2 contents:\n");
        for (i = 0; i < tlb_dbig_size(); i++) {
                d.value = dtlb_data_access_read(TLB_DBIG_1, i);
                t.value = dtlb_tag_read_read(TLB_DBIG_1, i);
                print_tlb_entry(i, t, d);
        }
}

#endif

void do_fast_instruction_access_mmu_miss_fault(istate_t *istate,
    uintptr_t va, const char *str)
{
        fault_if_from_uspace(istate, "%s, address=%p.", str, (void *) va);
        panic_memtrap(istate, PF_ACCESS_EXEC, va, str);
}

void do_fast_data_access_mmu_miss_fault(istate_t *istate,
    tlb_tag_access_reg_t tag, const char *str)
{
        uintptr_t va;

        va = tag.vpn << MMU_PAGE_WIDTH;
        fault_if_from_uspace(istate, "%s, page=%p (asid=%u).", str,
            (void *) va, tag.context);
        panic_memtrap(istate, PF_ACCESS_UNKNOWN, va, str);
}

void do_fast_data_access_protection_fault(istate_t *istate,
    tlb_tag_access_reg_t tag, const char *str)
{
        uintptr_t va;

        va = tag.vpn << MMU_PAGE_WIDTH;
        fault_if_from_uspace(istate, "%s, page=%p (asid=%u).", str,
            (void *) va, tag.context);
        panic_memtrap(istate, PF_ACCESS_WRITE, va, str);
}

void describe_dmmu_fault(void)
{
        tlb_sfsr_reg_t sfsr;
        uintptr_t sfar;

        sfsr.value = dtlb_sfsr_read();
        sfar = dtlb_sfar_read();
        
#if defined (US)
        printf("DTLB SFSR: asi=%#x, ft=%#x, e=%d, ct=%d, pr=%d, w=%d, ow=%d, "
            "fv=%d\n", sfsr.asi, sfsr.ft, sfsr.e, sfsr.ct, sfsr.pr, sfsr.w,
            sfsr.ow, sfsr.fv);
#elif defined (US3)
        printf("DTLB SFSR: nf=%d, asi=%#x, tm=%d, ft=%#x, e=%d, ct=%d, pr=%d, "
            "w=%d, ow=%d, fv=%d\n", sfsr.nf, sfsr.asi, sfsr.tm, sfsr.ft,
            sfsr.e, sfsr.ct, sfsr.pr, sfsr.w, sfsr.ow, sfsr.fv);
#endif
        
        printf("DTLB SFAR: address=%p\n", (void *) sfar);
        
        dtlb_sfsr_write(0);
}

void dump_sfsr_and_sfar(void)
{
        tlb_sfsr_reg_t sfsr;
        uintptr_t sfar;

        sfsr.value = dtlb_sfsr_read();
        sfar = dtlb_sfar_read();
        
#if defined (US)
        printf("DTLB SFSR: asi=%#x, ft=%#x, e=%d, ct=%d, pr=%d, w=%d, ow=%d, "
            "fv=%d\n", sfsr.asi, sfsr.ft, sfsr.e, sfsr.ct, sfsr.pr, sfsr.w,
            sfsr.ow, sfsr.fv);
#elif defined (US3)
        printf("DTLB SFSR: nf=%d, asi=%#x, tm=%d, ft=%#x, e=%d, ct=%d, pr=%d, "
            "w=%d, ow=%d, fv=%d\n", sfsr.nf, sfsr.asi, sfsr.tm, sfsr.ft,
            sfsr.e, sfsr.ct, sfsr.pr, sfsr.w, sfsr.ow, sfsr.fv);
#endif
            
        printf("DTLB SFAR: address=%p\n", (void *) sfar);
        
        dtlb_sfsr_write(0);
}

#if defined (US)
/** Invalidate all unlocked ITLB and DTLB entries. */
void tlb_invalidate_all(void)
{
        int i;
        
        /*
         * Walk all ITLB and DTLB entries and remove all unlocked mappings.
         *
         * The kernel doesn't use global mappings so any locked global mappings
         * found must have been created by someone else. Their only purpose now
         * is to collide with proper mappings. Invalidate immediately. It should
         * be safe to invalidate them as late as now.
         */

        tlb_data_t d;
        tlb_tag_read_reg_t t;

        for (i = 0; i < ITLB_ENTRY_COUNT; i++) {
                d.value = itlb_data_access_read(i);
                if (!d.l || d.g) {
                        t.value = itlb_tag_read_read(i);
                        d.v = false;
                        itlb_tag_access_write(t.value);
                        itlb_data_access_write(i, d.value);
                }
        }

        for (i = 0; i < DTLB_ENTRY_COUNT; i++) {
                d.value = dtlb_data_access_read(i);
                if (!d.l || d.g) {
                        t.value = dtlb_tag_read_read(i);
                        d.v = false;
                        dtlb_tag_access_write(t.value);
                        dtlb_data_access_write(i, d.value);
                }
        }

}

#elif defined (US3)

/** Invalidate all unlocked ITLB and DTLB entries. */
void tlb_invalidate_all(void)
{
        itlb_demap(TLB_DEMAP_ALL, 0, 0);
        dtlb_demap(TLB_DEMAP_ALL, 0, 0);
}

#endif

/** Invalidate all ITLB and DTLB entries that belong to specified ASID
 * (Context).
 *
 * @param asid Address Space ID.
 */
void tlb_invalidate_asid(asid_t asid)
{
        tlb_context_reg_t pc_save, ctx;
        
        /* switch to nucleus because we are mapped by the primary context */
        nucleus_enter();
        
        ctx.v = pc_save.v = mmu_primary_context_read();
        ctx.context = asid;
        mmu_primary_context_write(ctx.v);
        
        itlb_demap(TLB_DEMAP_CONTEXT, TLB_DEMAP_PRIMARY, 0);
        dtlb_demap(TLB_DEMAP_CONTEXT, TLB_DEMAP_PRIMARY, 0);
        
        mmu_primary_context_write(pc_save.v);
        
        nucleus_leave();
}

/** Invalidate all ITLB and DTLB entries for specified page range in specified
 * address space.
 *
 * @param asid          Address Space ID.
 * @param page          First page which to sweep out from ITLB and DTLB.
 * @param cnt           Number of ITLB and DTLB entries to invalidate.
 */
void tlb_invalidate_pages(asid_t asid, uintptr_t page, size_t cnt)
{
        unsigned int i;
        tlb_context_reg_t pc_save, ctx;
        
        /* switch to nucleus because we are mapped by the primary context */
        nucleus_enter();
        
        ctx.v = pc_save.v = mmu_primary_context_read();
        ctx.context = asid;
        mmu_primary_context_write(ctx.v);
        
        for (i = 0; i < cnt * MMU_PAGES_PER_PAGE; i++) {
                itlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_PRIMARY,
                    page + i * MMU_PAGE_SIZE);
                dtlb_demap(TLB_DEMAP_PAGE, TLB_DEMAP_PRIMARY,
                    page + i * MMU_PAGE_SIZE);
        }
        
        mmu_primary_context_write(pc_save.v);
        
        nucleus_leave();
}

/** @}
 */