/*-
 * Copyright (c) 2004 Marcel Moolenaar
 * Copyright (c) 2001 Doug Rabson
 * Copyright (c) 2016 The FreeBSD Foundation
 * All rights reserved.
 *
 * Portions of this software were developed by Konstantin Belousov
 * under sponsorship from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
 */

#include <sys/param.h>
#include <sys/efi.h>
#include <sys/kernel.h>
#include <sys/linker.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/clock.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/vmmeter.h>
#include <isa/rtc.h>
#include <machine/efi.h>
#include <machine/md_var.h>
#include <machine/vmparam.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/vm_phys.h>
#include <vm/vm_radix.h>

/* The EFI regions we're allowed to map. */
#define EFI_ALLOWED_TYPES_MASK ( \
    1u << EFI_MD_TYPE_BS_CODE | 1u << EFI_MD_TYPE_BS_DATA | \
    1u << EFI_MD_TYPE_RT_CODE | 1u << EFI_MD_TYPE_RT_DATA | \
    1u << EFI_MD_TYPE_FIRMWARE \
)

static pml5_entry_t *efi_pml5;
static pml4_entry_t *efi_pml4;
static vm_object_t obj_1t1_pt;
static vm_page_t efi_pmltop_page;
static vm_pindex_t efi_1t1_idx;

void
efi_destroy_1t1_map(void)
{
        struct pctrie_iter pages;
        vm_page_t m;

        if (obj_1t1_pt != NULL) {
                vm_page_iter_init(&pages, obj_1t1_pt);
                VM_OBJECT_RLOCK(obj_1t1_pt);
                VM_RADIX_FOREACH(m, &pages)
                        m->ref_count = VPRC_OBJREF;
                vm_wire_sub(obj_1t1_pt->resident_page_count);
                VM_OBJECT_RUNLOCK(obj_1t1_pt);
                vm_object_deallocate(obj_1t1_pt);
        }

        obj_1t1_pt = NULL;
        efi_pml4 = NULL;
        efi_pml5 = NULL;
        efi_pmltop_page = NULL;
}

/*
 * Map a physical address from EFI runtime space into KVA space.  Returns 0 to
 * indicate a failed mapping so that the caller may handle error.
 */
void *
efi_phys_to_kva(vm_paddr_t paddr)
{

        if (paddr >= dmaplimit)
                return (0);
        return (PHYS_TO_DMAP(paddr));
}

static vm_page_t
efi_1t1_page(void)
{

        return (vm_page_grab(obj_1t1_pt, efi_1t1_idx++, VM_ALLOC_NOBUSY |
            VM_ALLOC_WIRED | VM_ALLOC_ZERO));
}

static pt_entry_t *
efi_1t1_pte(vm_offset_t va)
{
        pml5_entry_t *pml5e;
        pml4_entry_t *pml4e;
        pdp_entry_t *pdpe;
        pd_entry_t *pde;
        pt_entry_t *pte;
        vm_page_t m;
        vm_pindex_t pml5_idx, pml4_idx, pdp_idx, pd_idx;
        vm_paddr_t mphys;

        pml4_idx = pmap_pml4e_index(va);
        if (la57) {
                pml5_idx = pmap_pml5e_index(va);
                pml5e = &efi_pml5[pml5_idx];
                if (*pml5e == 0) {
                        m = efi_1t1_page();
                        mphys = VM_PAGE_TO_PHYS(m);
                        *pml5e = mphys | X86_PG_RW | X86_PG_V;
                } else {
                        mphys = *pml5e & PG_FRAME;
                }
                pml4e = PHYS_TO_DMAP(mphys);
                pml4e = &pml4e[pml4_idx];
        } else {
                pml4e = &efi_pml4[pml4_idx];
        }

        if (*pml4e == 0) {
                m = efi_1t1_page();
                mphys =  VM_PAGE_TO_PHYS(m);
                *pml4e = mphys | X86_PG_RW | X86_PG_V;
        } else {
                mphys = *pml4e & PG_FRAME;
        }

        pdpe = PHYS_TO_DMAP(mphys);
        pdp_idx = pmap_pdpe_index(va);
        pdpe += pdp_idx;
        if (*pdpe == 0) {
                m = efi_1t1_page();
                mphys =  VM_PAGE_TO_PHYS(m);
                *pdpe = mphys | X86_PG_RW | X86_PG_V;
        } else {
                mphys = *pdpe & PG_FRAME;
        }

        pde = PHYS_TO_DMAP(mphys);
        pd_idx = pmap_pde_index(va);
        pde += pd_idx;
        if (*pde == 0) {
                m = efi_1t1_page();
                mphys = VM_PAGE_TO_PHYS(m);
                *pde = mphys | X86_PG_RW | X86_PG_V;
        } else {
                mphys = *pde & PG_FRAME;
        }

        pte = PHYS_TO_DMAP(mphys);
        pte += pmap_pte_index(va);
        KASSERT(*pte == 0, ("va %#jx *pt %#jx", va, *pte));

        return (pte);
}

bool
efi_create_1t1_map(struct efi_md *map, int ndesc, int descsz)
{
        struct efi_md *p;
        pt_entry_t *pte;
        void *pml;
        vm_page_t m;
        vm_offset_t va;
        uint64_t idx;
        int bits, i, mode;
        bool map_pz = true;

        obj_1t1_pt = vm_pager_allocate(OBJT_PHYS, NULL, ptoa(1 +
            NPML4EPG + NPML4EPG * NPDPEPG + NPML4EPG * NPDPEPG * NPDEPG),
            VM_PROT_ALL, 0, NULL);
        efi_1t1_idx = 0;
        VM_OBJECT_WLOCK(obj_1t1_pt);
        efi_pmltop_page = efi_1t1_page();
        VM_OBJECT_WUNLOCK(obj_1t1_pt);
        pml = VM_PAGE_TO_DMAP(efi_pmltop_page);
        if (la57) {
                efi_pml5 = pml;
                pmap_pinit_pml5(efi_pmltop_page);
        } else {
                efi_pml4 = pml;
                pmap_pinit_pml4(efi_pmltop_page);
        }

        if ((efi_map_regs & ~EFI_ALLOWED_TYPES_MASK) != 0) {
                printf("Ignoring the following runtime EFI regions: %#x\n",
                    efi_map_regs & ~EFI_ALLOWED_TYPES_MASK);
                efi_map_regs &= EFI_ALLOWED_TYPES_MASK;
        }

        for (i = 0, p = map; i < ndesc; i++, p = efi_next_descriptor(p,
            descsz)) {
                if ((p->md_attr & EFI_MD_ATTR_RT) == 0 &&
                    !EFI_MAP_BOOTTYPE_ALLOWED(p->md_type))
                        continue;
                if (p->md_virt != 0 && p->md_virt != p->md_phys) {
                        if (bootverbose)
                                printf("EFI Runtime entry %d is mapped\n", i);
                        goto fail;
                }
                if ((p->md_phys & EFI_PAGE_MASK) != 0) {
                        if (bootverbose)
                                printf("EFI Runtime entry %d is not aligned\n",
                                    i);
                        goto fail;
                }
                if (p->md_phys + p->md_pages * EFI_PAGE_SIZE < p->md_phys ||
                    p->md_phys + p->md_pages * EFI_PAGE_SIZE >=
                    VM_MAXUSER_ADDRESS) {
                        printf("EFI Runtime entry %d is not in mappable for RT:"
                            "base %#016jx %#jx pages\n",
                            i, (uintmax_t)p->md_phys,
                            (uintmax_t)p->md_pages);
                        goto fail;
                }
                if ((p->md_attr & EFI_MD_ATTR_WB) != 0)
                        mode = VM_MEMATTR_WRITE_BACK;
                else if ((p->md_attr & EFI_MD_ATTR_WT) != 0)
                        mode = VM_MEMATTR_WRITE_THROUGH;
                else if ((p->md_attr & EFI_MD_ATTR_WC) != 0)
                        mode = VM_MEMATTR_WRITE_COMBINING;
                else if ((p->md_attr & EFI_MD_ATTR_WP) != 0)
                        mode = VM_MEMATTR_WRITE_PROTECTED;
                else if ((p->md_attr & EFI_MD_ATTR_UC) != 0)
                        mode = VM_MEMATTR_UNCACHEABLE;
                else {
                        if (bootverbose)
                                printf("EFI Runtime entry %d mapping "
                                    "attributes unsupported\n", i);
                        mode = VM_MEMATTR_UNCACHEABLE;
                }
                (void)vm_phys_fictitious_reg_range(p->md_phys, p->md_phys +
                    p->md_pages * EFI_PAGE_SIZE, mode);
                bits = pmap_cache_bits(kernel_pmap, mode, false) | X86_PG_RW |
                    X86_PG_V;
                VM_OBJECT_WLOCK(obj_1t1_pt);
                for (va = p->md_phys, idx = 0; idx < p->md_pages; idx++,
                    va += PAGE_SIZE) {
                        pte = efi_1t1_pte(va);
                        pte_store(pte, va | bits);

                        m = PHYS_TO_VM_PAGE(va);
                        if (m != NULL && VM_PAGE_TO_PHYS(m) == 0) {
                                vm_page_init_page(m, va, -1,
                                    VM_FREEPOOL_DEFAULT);
                                m->order = VM_NFREEORDER + 1; /* invalid */
                                m->pool = VM_NFREEPOOL + 1; /* invalid */
                                pmap_page_set_memattr_noflush(m, mode);
                        }
                }
                VM_OBJECT_WUNLOCK(obj_1t1_pt);
                if (p->md_phys == 0)
                        map_pz = false;
        }

        /*
         * Some BIOSes tend to access phys 0 during efirt calls,
         * so map it if we haven't yet.
         */
        if (map_pz) {
                VM_OBJECT_WLOCK(obj_1t1_pt);
                pte = efi_1t1_pte(0);
                /* Assume Write-Back */
                bits = pmap_cache_bits(kernel_pmap, VM_MEMATTR_WRITE_BACK,
                    false) | X86_PG_RW | X86_PG_V;
                pte_store(pte, bits);
                VM_OBJECT_WUNLOCK(obj_1t1_pt);
        }

        return (true);

fail:
        efi_destroy_1t1_map();
        return (false);
}

/*
 * Create an environment for the EFI runtime code call.  The most
 * important part is creating the required 1:1 physical->virtual
 * mappings for the runtime segments.  To do that, we manually create
 * page table which unmap userspace but gives correct kernel mapping.
 * The 1:1 mappings for runtime segments usually occupy low 4G of the
 * physical address map.
 *
 * The 1:1 mappings were chosen over the SetVirtualAddressMap() EFI RT
 * service, because there are some BIOSes which fail to correctly
 * relocate itself on the call, requiring both 1:1 and virtual
 * mapping.  As result, we must provide 1:1 mapping anyway, so no
 * reason to bother with the virtual map, and no need to add a
 * complexity into loader.
 *
 * There is no need to disable interrupts around the change of %cr3,
 * the kernel mappings are correct, while we only grabbed the
 * userspace portion of VA.  Interrupts handlers must not access
 * userspace.  Having interrupts enabled fixes the issue with
 * firmware/SMM long operation, which would negatively affect IPIs,
 * esp. TLB shootdown requests.
 */
int
efi_arch_enter(void)
{
        pmap_t curpmap;
        uint64_t cr3;

        curpmap = PCPU_GET(curpmap);
        PMAP_LOCK_ASSERT(curpmap, MA_OWNED);
        curthread->td_md.md_efirt_dis_pf = vm_fault_disable_pagefaults();

        /*
         * IPI TLB shootdown handler invltlb_pcid_handler() reloads
         * %cr3 from the curpmap->pm_cr3, which would disable runtime
         * segments mappings.  Block the handler's action by setting
         * curpmap to impossible value.  See also comment in
         * pmap.c:pmap_activate_sw().
         */
        if (pmap_pcid_enabled && !invpcid_works)
                PCPU_SET(curpmap, NULL);

        cr3 = VM_PAGE_TO_PHYS(efi_pmltop_page);
        if (pmap_pcid_enabled)
                cr3 |= pmap_get_pcid(curpmap);
        load_cr3(cr3);
        /*
         * If PCID is enabled, the clear CR3_PCID_SAVE bit in the loaded %cr3
         * causes TLB invalidation.
         */
        if (!pmap_pcid_enabled)
                invltlb();
        if (lass_enabled)
                load_cr4(rcr4() & ~CR4_LASS);
        return (0);
}

void
efi_arch_leave(void)
{
        pmap_t curpmap;
        uint64_t cr3;

        if (lass_enabled)
                load_cr4(rcr4() | CR4_LASS);
        curpmap = &curproc->p_vmspace->vm_pmap;
        cr3 = curpmap->pm_cr3;
        if (pmap_pcid_enabled) {
                cr3 |= pmap_get_pcid(curpmap);
                if (!invpcid_works)
                        PCPU_SET(curpmap, curpmap);
        }
        load_cr3(cr3);
        if (!pmap_pcid_enabled)
                invltlb();
        vm_fault_enable_pagefaults(curthread->td_md.md_efirt_dis_pf);
}

/* XXX debug stuff */
static int
efi_time_sysctl_handler(SYSCTL_HANDLER_ARGS)
{
        struct efi_tm tm;
        int error, val;

        val = 0;
        error = sysctl_handle_int(oidp, &val, 0, req);
        if (error != 0 || req->newptr == NULL)
                return (error);
        error = efi_get_time(&tm);
        if (error == 0) {
                uprintf("EFI reports: Year %d Month %d Day %d Hour %d Min %d "
                    "Sec %d\n", tm.tm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour,
                    tm.tm_min, tm.tm_sec);
        }
        return (error);
}

SYSCTL_PROC(_debug, OID_AUTO, efi_time,
    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 0,
    efi_time_sysctl_handler, "I",
    "");