root/usr/src/uts/sun4v/vm/mach_sfmmu.c
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <vm/hat.h>
#include <vm/hat_sfmmu.h>
#include <vm/page.h>
#include <sys/pte.h>
#include <sys/systm.h>
#include <sys/mman.h>
#include <sys/sysmacros.h>
#include <sys/machparam.h>
#include <sys/vtrace.h>
#include <sys/kmem.h>
#include <sys/mmu.h>
#include <sys/cmn_err.h>
#include <sys/cpu.h>
#include <sys/cpuvar.h>
#include <sys/debug.h>
#include <sys/lgrp.h>
#include <sys/archsystm.h>
#include <sys/machsystm.h>
#include <sys/vmsystm.h>
#include <sys/bitmap.h>
#include <vm/rm.h>
#include <sys/t_lock.h>
#include <sys/vm_machparam.h>
#include <sys/promif.h>
#include <sys/prom_isa.h>
#include <sys/prom_plat.h>
#include <sys/prom_debug.h>
#include <sys/privregs.h>
#include <sys/bootconf.h>
#include <sys/memlist.h>
#include <sys/memlist_plat.h>
#include <sys/cpu_module.h>
#include <sys/reboot.h>
#include <sys/kdi.h>
#include <sys/hypervisor_api.h>

/*
 * External routines and data structures
 */
extern void     sfmmu_cache_flushcolor(int, pfn_t);
extern uint_t   mmu_page_sizes;

/*
 * Static routines
 */
static void     sfmmu_set_tlb(void);

/*
 * Global Data:
 */
caddr_t textva, datava;
tte_t   ktext_tte, kdata_tte;           /* ttes for kernel text and data */

int     enable_bigktsb = 1;
int     shtsb4m_first = 0;

tte_t bigktsb_ttes[MAX_BIGKTSB_TTES];
int bigktsb_nttes = 0;

/*
 * Controls the logic which enables the use of the
 * QUAD_LDD_PHYS ASI for TSB accesses.
 */
int     ktsb_phys = 1;

#ifdef SET_MMU_STATS
struct mmu_stat mmu_stat_area[NCPU];
#endif /* SET_MMU_STATS */

#ifdef DEBUG
/*
 * The following two variables control if the hypervisor/hardware will
 * be used to do the TSB table walk for kernel and user contexts.
 */
int hv_use_0_tsb = 1;
int hv_use_non0_tsb = 1;
#endif /* DEBUG */

static void
sfmmu_set_fault_status_area(void)
{
        caddr_t mmfsa_va;
        extern  caddr_t mmu_fault_status_area;

        mmfsa_va =
            mmu_fault_status_area + (MMFSA_SIZE  * getprocessorid());
        set_mmfsa_scratchpad(mmfsa_va);
        prom_set_mmfsa_traptable(&trap_table, va_to_pa(mmfsa_va));
}

void
sfmmu_set_tsbs()
{
        uint64_t rv;
        struct hv_tsb_block *hvbp = &ksfmmup->sfmmu_hvblock;

#ifdef DEBUG
        if (hv_use_0_tsb == 0)
                return;
#endif /* DEBUG */

        rv = hv_set_ctx0(hvbp->hv_tsb_info_cnt,
            hvbp->hv_tsb_info_pa);
        if (rv != H_EOK)
                prom_printf("cpu%d: hv_set_ctx0() returned %lx\n",
                    getprocessorid(), rv);

#ifdef SET_MMU_STATS
        ASSERT(getprocessorid() < NCPU);
        rv = hv_mmu_set_stat_area(va_to_pa(&mmu_stat_area[getprocessorid()]),
            sizeof (mmu_stat_area[0]));
        if (rv != H_EOK)
                prom_printf("cpu%d: hv_mmu_set_stat_area() returned %lx\n",
                    getprocessorid(), rv);
#endif /* SET_MMU_STATS */
}

/*
 * This routine remaps the kernel using large ttes
 * All entries except locked ones will be removed from the tlb.
 * It assumes that both the text and data segments reside in a separate
 * 4mb virtual and physical contigous memory chunk.  This routine
 * is only executed by the first cpu.  The remaining cpus execute
 * sfmmu_mp_startup() instead.
 * XXX It assumes that the start of the text segment is KERNELBASE.  It should
 * actually be based on start.
 */
void
sfmmu_remap_kernel(void)
{
        pfn_t   pfn;
        uint_t  attr;
        int     flags;

        extern char end[];
        extern struct as kas;

        textva = (caddr_t)(KERNELBASE & MMU_PAGEMASK4M);
        pfn = va_to_pfn(textva);
        if (pfn == PFN_INVALID)
                prom_panic("can't find kernel text pfn");
        pfn &= TTE_PFNMASK(TTE4M);

        attr = PROC_TEXT | HAT_NOSYNC;
        flags = HAT_LOAD_LOCK | SFMMU_NO_TSBLOAD;
        sfmmu_memtte(&ktext_tte, pfn, attr, TTE4M);
        /*
         * We set the lock bit in the tte to lock the translation in
         * the tlb.
         */
        TTE_SET_LOCKED(&ktext_tte);
        sfmmu_tteload(kas.a_hat, &ktext_tte, textva, NULL, flags);

        datava = (caddr_t)((uintptr_t)end & MMU_PAGEMASK4M);
        pfn = va_to_pfn(datava);
        if (pfn == PFN_INVALID)
                prom_panic("can't find kernel data pfn");
        pfn &= TTE_PFNMASK(TTE4M);

        attr = PROC_DATA | HAT_NOSYNC;
        sfmmu_memtte(&kdata_tte, pfn, attr, TTE4M);
        /*
         * We set the lock bit in the tte to lock the translation in
         * the tlb.  We also set the mod bit to avoid taking dirty bit
         * traps on kernel data.
         */
        TTE_SET_LOCKED(&kdata_tte);
        TTE_SET_LOFLAGS(&kdata_tte, 0, TTE_HWWR_INT);
        sfmmu_tteload(kas.a_hat, &kdata_tte, datava,
            (struct page *)NULL, flags);

        /*
         * create bigktsb ttes if necessary.
         */
        if (enable_bigktsb) {
                int i = 0;
                caddr_t va = ktsb_base;
                size_t tsbsz = ktsb_sz;
                tte_t tte;

                ASSERT(va >= datava + MMU_PAGESIZE4M);
                ASSERT(tsbsz >= MMU_PAGESIZE4M);
                ASSERT(IS_P2ALIGNED(tsbsz, tsbsz));
                ASSERT(IS_P2ALIGNED(va, tsbsz));
                attr = PROC_DATA | HAT_NOSYNC;
                while (tsbsz != 0) {
                        ASSERT(i < MAX_BIGKTSB_TTES);
                        pfn = va_to_pfn(va);
                        ASSERT(pfn != PFN_INVALID);
                        ASSERT((pfn & ~TTE_PFNMASK(TTE4M)) == 0);
                        sfmmu_memtte(&tte, pfn, attr, TTE4M);
                        ASSERT(TTE_IS_MOD(&tte));
                        /*
                         * No need to lock if we use physical addresses.
                         * Since we invalidate the kernel TSB using virtual
                         * addresses, it's an optimization to load them now
                         * so that we won't have to load them later.
                         */
                        if (!ktsb_phys) {
                                TTE_SET_LOCKED(&tte);
                        }
                        sfmmu_tteload(kas.a_hat, &tte, va, NULL, flags);
                        bigktsb_ttes[i] = tte;
                        va += MMU_PAGESIZE4M;
                        tsbsz -= MMU_PAGESIZE4M;
                        i++;
                }
                bigktsb_nttes = i;
        }

        sfmmu_set_tlb();
}

/*
 * Setup the kernel's locked tte's
 */
void
sfmmu_set_tlb(void)
{
        (void) hv_mmu_map_perm_addr(textva, KCONTEXT, *(uint64_t *)&ktext_tte,
            MAP_ITLB | MAP_DTLB);
        (void) hv_mmu_map_perm_addr(datava, KCONTEXT, *(uint64_t *)&kdata_tte,
            MAP_DTLB);

        if (!ktsb_phys && enable_bigktsb) {
                int i;
                caddr_t va = ktsb_base;
                uint64_t tte;

                ASSERT(bigktsb_nttes <= MAX_BIGKTSB_TTES);
                for (i = 0; i < bigktsb_nttes; i++) {
                        tte = *(uint64_t *)&bigktsb_ttes[i];
                        (void) hv_mmu_map_perm_addr(va, KCONTEXT, tte,
                            MAP_DTLB);
                        va += MMU_PAGESIZE4M;
                }
        }
}

/*
 * This routine is executed by all other cpus except the first one
 * at initialization time.  It is responsible for taking over the
 * mmu from the prom.  We follow these steps.
 * Lock the kernel's ttes in the TLB
 * Initialize the tsb hardware registers
 * Take over the trap table
 * Flush the prom's locked entries from the TLB
 */
void
sfmmu_mp_startup(void)
{
        sfmmu_set_tlb();
        setwstate(WSTATE_KERN);
        /*
         * sfmmu_set_fault_status_area() takes over trap_table
         */
        sfmmu_set_fault_status_area();
        sfmmu_set_tsbs();
        install_va_to_tte();
}

void
kdi_tlb_page_lock(caddr_t va, int do_dtlb)
{
        tte_t tte;
        pfn_t pfn = va_to_pfn(va);
        uint64_t ret;

        sfmmu_memtte(&tte, pfn, (PROC_TEXT | HAT_NOSYNC), TTE8K);
        ret = hv_mmu_map_perm_addr(va, KCONTEXT, *(uint64_t *)&tte,
            MAP_ITLB | (do_dtlb ? MAP_DTLB : 0));

        if (ret != H_EOK) {
                cmn_err(CE_PANIC, "cpu%d: cannot set permanent mapping for "
                    "va=0x%p, hv error code 0x%lx",
                    getprocessorid(), (void *)va, ret);
        }
}

void
kdi_tlb_page_unlock(caddr_t va, int do_dtlb)
{
        (void) hv_mmu_unmap_perm_addr(va, KCONTEXT,
            MAP_ITLB | (do_dtlb ? MAP_DTLB : 0));
}

/*
 * Clear machine specific TSB information for a user process
 */
void
sfmmu_clear_utsbinfo()
{
        (void) hv_set_ctxnon0(0, 0);
}

/*
 * The tsbord[] array is set up to translate from the order of tsbs in the sfmmu
 * list to the order of tsbs in the tsb descriptor array passed to the hv, which
 * is the search order used during Hardware Table Walk.
 * So, the tsb with index i in the sfmmu list will have search order tsbord[i].
 *
 * The order of tsbs in the sfmmu list will be as follows:
 *
 *              0 8K - 512K private TSB
 *              1 4M - 256M private TSB
 *              2 8K - 512K shared TSB
 *              3 4M - 256M shared TSB
 *
 * Shared TSBs are only used if a process is part of an SCD.
 *
 * So, e.g. tsbord[3] = 1;
 *         corresponds to searching the shared 4M TSB second.
 *
 * The search order is selected so that the 8K-512K private TSB is always first.
 * Currently shared context is not expected to map many 8K-512K pages that cause
 * TLB misses so we order the shared TSB for 4M-256M pages in front of the
 * shared TSB for 8K-512K pages. We also expect more TLB misses against private
 * context mappings than shared context mappings and place private TSBs ahead of
 * shared TSBs in descriptor order. The shtsb4m_first /etc/system tuneable can
 * be used to change the default ordering of private and shared TSBs for
 * 4M-256M pages.
 */
void
sfmmu_setup_tsbinfo(sfmmu_t *sfmmup)
{
        struct tsb_info         *tsbinfop;
        hv_tsb_info_t           *tdp;
        int                     i;
        int                     j;
        int                     scd = 0;
        int                     tsbord[NHV_TSB_INFO];

#ifdef DEBUG
        ASSERT(max_mmu_ctxdoms > 0);
        if (sfmmup != ksfmmup) {
                /* Process should have INVALID_CONTEXT on all MMUs. */
                for (i = 0; i < max_mmu_ctxdoms; i++) {
                        ASSERT(sfmmup->sfmmu_ctxs[i].cnum == INVALID_CONTEXT);
                }
        }
#endif

        tsbinfop = sfmmup->sfmmu_tsb;
        if (tsbinfop == NULL) {
                sfmmup->sfmmu_hvblock.hv_tsb_info_pa = (uint64_t)-1;
                sfmmup->sfmmu_hvblock.hv_tsb_info_cnt = 0;
                return;
        }

        ASSERT(sfmmup != ksfmmup || sfmmup->sfmmu_scdp == NULL);
        ASSERT(sfmmup->sfmmu_scdp == NULL ||
            sfmmup->sfmmu_scdp->scd_sfmmup->sfmmu_tsb != NULL);

        tsbord[0] = 0;
        if (sfmmup->sfmmu_scdp == NULL) {
                tsbord[1] = 1;
        } else {
                struct tsb_info *scd8ktsbp =
                    sfmmup->sfmmu_scdp->scd_sfmmup->sfmmu_tsb;
                ulong_t shared_4mttecnt = 0;
                ulong_t priv_4mttecnt = 0;
                int scd4mtsb = (scd8ktsbp->tsb_next != NULL);

                for (i = TTE4M; i < MMU_PAGE_SIZES; i++) {
                        if (scd4mtsb) {
                                shared_4mttecnt +=
                                    sfmmup->sfmmu_scdismttecnt[i] +
                                    sfmmup->sfmmu_scdrttecnt[i];
                        }
                        if (tsbinfop->tsb_next != NULL) {
                                priv_4mttecnt += sfmmup->sfmmu_ttecnt[i] +
                                    sfmmup->sfmmu_ismttecnt[i];
                        }
                }
                if (tsbinfop->tsb_next == NULL) {
                        if (shared_4mttecnt) {
                                tsbord[1] = 2;
                                tsbord[2] = 1;
                        } else {
                                tsbord[1] = 1;
                                tsbord[2] = 2;
                        }
                } else if (priv_4mttecnt) {
                        if (shared_4mttecnt) {
                                tsbord[1] = shtsb4m_first ? 2 : 1;
                                tsbord[2] = 3;
                                tsbord[3] = shtsb4m_first ? 1 : 2;
                        } else {
                                tsbord[1] = 1;
                                tsbord[2] = 2;
                                tsbord[3] = 3;
                        }
                } else if (shared_4mttecnt) {
                        tsbord[1] = 3;
                        tsbord[2] = 2;
                        tsbord[3] = 1;
                } else {
                        tsbord[1] = 2;
                        tsbord[2] = 1;
                        tsbord[3] = 3;
                }
        }

        ASSERT(tsbinfop != NULL);
        for (i = 0; tsbinfop != NULL && i < NHV_TSB_INFO; i++) {
                if (i == 0) {
                        tdp = &sfmmup->sfmmu_hvblock.hv_tsb_info[i];
                        sfmmup->sfmmu_hvblock.hv_tsb_info_pa = va_to_pa(tdp);
                }


                j = tsbord[i];

                tdp = &sfmmup->sfmmu_hvblock.hv_tsb_info[j];

                ASSERT(tsbinfop->tsb_ttesz_mask != 0);
                tdp->hvtsb_idxpgsz = lowbit(tsbinfop->tsb_ttesz_mask) - 1;
                tdp->hvtsb_assoc = 1;
                tdp->hvtsb_ntte = TSB_ENTRIES(tsbinfop->tsb_szc);
                tdp->hvtsb_ctx_index = scd;
                tdp->hvtsb_pgszs = tsbinfop->tsb_ttesz_mask;
                tdp->hvtsb_rsvd = 0;
                tdp->hvtsb_pa = tsbinfop->tsb_pa;

                tsbinfop = tsbinfop->tsb_next;
                if (tsbinfop == NULL && !scd && sfmmup->sfmmu_scdp != NULL) {
                        tsbinfop =
                            sfmmup->sfmmu_scdp->scd_sfmmup->sfmmu_tsb;
                        scd = 1;
                }
        }
        sfmmup->sfmmu_hvblock.hv_tsb_info_cnt = i;
        ASSERT(tsbinfop == NULL);
}

/*
 * Invalidate a TSB via processor specific TSB invalidation routine
 */
void
sfmmu_inv_tsb(caddr_t tsb_base, uint_t tsb_bytes)
{
        extern void cpu_inv_tsb(caddr_t, uint_t);

        cpu_inv_tsb(tsb_base, tsb_bytes);
}

/*
 * Completely flush the D-cache on all cpus.
 * Not applicable to sun4v.
 */
void
sfmmu_cache_flushall()
{
}