efi.c

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/*
 * Extensible Firmware Interface
 *
 * Based on Extensible Firmware Interface Specification version 0.9
 * April 30, 1999
 *
 * Copyright (C) 1999 VA Linux Systems
 * Copyright (C) 1999 Walt Drummond <[email protected]>
 * Copyright (C) 1999-2003 Hewlett-Packard Co.
 *  David Mosberger-Tang <[email protected]>
 *  Stephane Eranian <[email protected]>
 * (c) Copyright 2006 Hewlett-Packard Development Company, L.P.
 *  Bjorn Helgaas <[email protected]>
 *
 * All EFI Runtime Services are not implemented yet as EFI only
 * supports physical mode addressing on SoftSDV. This is to be fixed
 * in a future version.  --drummond 1999-07-20
 *
 * Implemented EFI runtime services and virtual mode calls.  --davidm
 *
 * Goutham Rao: <[email protected]>
 *  Skip non-WB memory and ignore empty memory ranges.
 */
#include <linux/module.h>
#include <linux/bootmem.h>
#include <linux/crash_dump.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/efi.h>
#include <linux/kexec.h>
#include <linux/mm.h>

#include <asm/io.h>
#include <asm/kregs.h>
#include <asm/meminit.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/mca.h>
#include <asm/setup.h>
#include <asm/tlbflush.h>

#define EFI_DEBUG   0

extern efi_status_t efi_call_phys (void *, ...);

struct efi efi;
EXPORT_SYMBOL(efi);
static efi_runtime_services_t *runtime;
static u64 mem_limit = ~0UL, max_addr = ~0UL, min_addr = 0UL;

#define efi_call_virt(f, args...)   (*(f))(args)

#define STUB_GET_TIME(prefix, adjust_arg)                      \
static efi_status_t                                \
prefix##_get_time (efi_time_t *tm, efi_time_cap_t *tc)                 \
{                                          \
    struct ia64_fpreg fr[6];                           \
    efi_time_cap_t *atc = NULL;                        \
    efi_status_t ret;                              \
                                           \
    if (tc)                                    \
        atc = adjust_arg(tc);                          \
    ia64_save_scratch_fpregs(fr);                          \
    ret = efi_call_##prefix((efi_get_time_t *) __va(runtime->get_time),    \
                adjust_arg(tm), atc);                  \
    ia64_load_scratch_fpregs(fr);                          \
    return ret;                                \
}

#define STUB_SET_TIME(prefix, adjust_arg)                      \
static efi_status_t                                \
prefix##_set_time (efi_time_t *tm)                         \
{                                          \
    struct ia64_fpreg fr[6];                           \
    efi_status_t ret;                              \
                                           \
    ia64_save_scratch_fpregs(fr);                          \
    ret = efi_call_##prefix((efi_set_time_t *) __va(runtime->set_time),    \
                adjust_arg(tm));                   \
    ia64_load_scratch_fpregs(fr);                          \
    return ret;                                \
}

#define STUB_GET_WAKEUP_TIME(prefix, adjust_arg)                   \
static efi_status_t                                \
prefix##_get_wakeup_time (efi_bool_t *enabled, efi_bool_t *pending,        \
              efi_time_t *tm)                      \
{                                          \
    struct ia64_fpreg fr[6];                           \
    efi_status_t ret;                              \
                                           \
    ia64_save_scratch_fpregs(fr);                          \
    ret = efi_call_##prefix(                           \
        (efi_get_wakeup_time_t *) __va(runtime->get_wakeup_time),      \
        adjust_arg(enabled), adjust_arg(pending), adjust_arg(tm));     \
    ia64_load_scratch_fpregs(fr);                          \
    return ret;                                \
}

#define STUB_SET_WAKEUP_TIME(prefix, adjust_arg)                   \
static efi_status_t                                \
prefix##_set_wakeup_time (efi_bool_t enabled, efi_time_t *tm)              \
{                                          \
    struct ia64_fpreg fr[6];                           \
    efi_time_t *atm = NULL;                            \
    efi_status_t ret;                              \
                                           \
    if (tm)                                    \
        atm = adjust_arg(tm);                          \
    ia64_save_scratch_fpregs(fr);                          \
    ret = efi_call_##prefix(                           \
        (efi_set_wakeup_time_t *) __va(runtime->set_wakeup_time),      \
        enabled, atm);                             \
    ia64_load_scratch_fpregs(fr);                          \
    return ret;                                \
}

#define STUB_GET_VARIABLE(prefix, adjust_arg)                      \
static efi_status_t                                \
prefix##_get_variable (efi_char16_t *name, efi_guid_t *vendor, u32 *attr,      \
               unsigned long *data_size, void *data)               \
{                                          \
    struct ia64_fpreg fr[6];                           \
    u32 *aattr = NULL;                             \
    efi_status_t ret;                              \
                                           \
    if (attr)                                  \
        aattr = adjust_arg(attr);                      \
    ia64_save_scratch_fpregs(fr);                          \
    ret = efi_call_##prefix(                           \
        (efi_get_variable_t *) __va(runtime->get_variable),        \
        adjust_arg(name), adjust_arg(vendor), aattr,               \
        adjust_arg(data_size), adjust_arg(data));              \
    ia64_load_scratch_fpregs(fr);                          \
    return ret;                                \
}

#define STUB_GET_NEXT_VARIABLE(prefix, adjust_arg)                 \
static efi_status_t                                \
prefix##_get_next_variable (unsigned long *name_size, efi_char16_t *name,      \
                efi_guid_t *vendor)                    \
{                                          \
    struct ia64_fpreg fr[6];                           \
    efi_status_t ret;                              \
                                           \
    ia64_save_scratch_fpregs(fr);                          \
    ret = efi_call_##prefix(                           \
        (efi_get_next_variable_t *) __va(runtime->get_next_variable),  \
        adjust_arg(name_size), adjust_arg(name), adjust_arg(vendor));  \
    ia64_load_scratch_fpregs(fr);                          \
    return ret;                                \
}

#define STUB_SET_VARIABLE(prefix, adjust_arg)                      \
static efi_status_t                                \
prefix##_set_variable (efi_char16_t *name, efi_guid_t *vendor,             \
               u32 attr, unsigned long data_size,              \
               void *data)                         \
{                                          \
    struct ia64_fpreg fr[6];                           \
    efi_status_t ret;                              \
                                           \
    ia64_save_scratch_fpregs(fr);                          \
    ret = efi_call_##prefix(                           \
        (efi_set_variable_t *) __va(runtime->set_variable),        \
        adjust_arg(name), adjust_arg(vendor), attr, data_size,         \
        adjust_arg(data));                         \
    ia64_load_scratch_fpregs(fr);                          \
    return ret;                                \
}

#define STUB_GET_NEXT_HIGH_MONO_COUNT(prefix, adjust_arg)              \
static efi_status_t                                \
prefix##_get_next_high_mono_count (u32 *count)                     \
{                                          \
    struct ia64_fpreg fr[6];                           \
    efi_status_t ret;                              \
                                           \
    ia64_save_scratch_fpregs(fr);                          \
    ret = efi_call_##prefix((efi_get_next_high_mono_count_t *)         \
                __va(runtime->get_next_high_mono_count),       \
                adjust_arg(count));                \
    ia64_load_scratch_fpregs(fr);                          \
    return ret;                                \
}

#define STUB_RESET_SYSTEM(prefix, adjust_arg)                      \
static void                                    \
prefix##_reset_system (int reset_type, efi_status_t status,            \
               unsigned long data_size, efi_char16_t *data)        \
{                                          \
    struct ia64_fpreg fr[6];                           \
    efi_char16_t *adata = NULL;                        \
                                           \
    if (data)                                  \
        adata = adjust_arg(data);                      \
                                           \
    ia64_save_scratch_fpregs(fr);                          \
    efi_call_##prefix(                             \
        (efi_reset_system_t *) __va(runtime->reset_system),        \
        reset_type, status, data_size, adata);                 \
    /* should not return, but just in case... */                   \
    ia64_load_scratch_fpregs(fr);                          \
}

#define phys_ptr(arg)   ((__typeof__(arg)) ia64_tpa(arg))

STUB_GET_TIME(phys, phys_ptr)
STUB_SET_TIME(phys, phys_ptr)
STUB_GET_WAKEUP_TIME(phys, phys_ptr)
STUB_SET_WAKEUP_TIME(phys, phys_ptr)
STUB_GET_VARIABLE(phys, phys_ptr)
STUB_GET_NEXT_VARIABLE(phys, phys_ptr)
STUB_SET_VARIABLE(phys, phys_ptr)
STUB_GET_NEXT_HIGH_MONO_COUNT(phys, phys_ptr)
STUB_RESET_SYSTEM(phys, phys_ptr)

#define id(arg) arg

STUB_GET_TIME(virt, id)
STUB_SET_TIME(virt, id)
STUB_GET_WAKEUP_TIME(virt, id)
STUB_SET_WAKEUP_TIME(virt, id)
STUB_GET_VARIABLE(virt, id)
STUB_GET_NEXT_VARIABLE(virt, id)
STUB_SET_VARIABLE(virt, id)
STUB_GET_NEXT_HIGH_MONO_COUNT(virt, id)
STUB_RESET_SYSTEM(virt, id)

void
efi_gettimeofday (struct timespec *ts)
{
    efi_time_t tm;

    if ((*efi.get_time)(&tm, NULL) != EFI_SUCCESS) {
        memset(ts, 0, sizeof(*ts));
        return;
    }

    ts->tv_sec = mktime(tm.year, tm.month, tm.day,
                tm.hour, tm.minute, tm.second);
    ts->tv_nsec = tm.nanosecond;
}

static int
is_memory_available (efi_memory_desc_t *md)
{
    if (!(md->attribute & EFI_MEMORY_WB))
        return 0;

    switch (md->type) {
          case EFI_LOADER_CODE:
          case EFI_LOADER_DATA:
          case EFI_BOOT_SERVICES_CODE:
          case EFI_BOOT_SERVICES_DATA:
          case EFI_CONVENTIONAL_MEMORY:
        return 1;
    }
    return 0;
}

typedef struct kern_memdesc {
    u64 attribute;
    u64 start;
    u64 num_pages;
} kern_memdesc_t;

static kern_memdesc_t *kern_memmap;

#define efi_md_size(md) (md->num_pages << EFI_PAGE_SHIFT)

static inline u64
kmd_end(kern_memdesc_t *kmd)
{
    return (kmd->start + (kmd->num_pages << EFI_PAGE_SHIFT));
}

static inline u64
efi_md_end(efi_memory_desc_t *md)
{
    return (md->phys_addr + efi_md_size(md));
}

static inline int
efi_wb(efi_memory_desc_t *md)
{
    return (md->attribute & EFI_MEMORY_WB);
}

static inline int
efi_uc(efi_memory_desc_t *md)
{
    return (md->attribute & EFI_MEMORY_UC);
}

static void
walk (efi_freemem_callback_t callback, void *arg, u64 attr)
{
    kern_memdesc_t *k;
    u64 start, end, voff;

    voff = (attr == EFI_MEMORY_WB) ? PAGE_OFFSET : __IA64_UNCACHED_OFFSET;
    for (k = kern_memmap; k->start != ~0UL; k++) {
        if (k->attribute != attr)
            continue;
        start = PAGE_ALIGN(k->start);
        end = (k->start + (k->num_pages << EFI_PAGE_SHIFT)) & PAGE_MASK;
        if (start < end)
            if ((*callback)(start + voff, end + voff, arg) < 0)
                return;
    }
}

/*
 * Walk the EFI memory map and call CALLBACK once for each EFI memory
 * descriptor that has memory that is available for OS use.
 */
void
efi_memmap_walk (efi_freemem_callback_t callback, void *arg)
{
    walk(callback, arg, EFI_MEMORY_WB);
}

/*
 * Walk the EFI memory map and call CALLBACK once for each EFI memory
 * descriptor that has memory that is available for uncached allocator.
 */
void
efi_memmap_walk_uc (efi_freemem_callback_t callback, void *arg)
{
    walk(callback, arg, EFI_MEMORY_UC);
}

/*
 * Look for the PAL_CODE region reported by EFI and map it using an
 * ITR to enable safe PAL calls in virtual mode.  See IA-64 Processor
 * Abstraction Layer chapter 11 in ADAG
 */
void *
efi_get_pal_addr (void)
{
    void *efi_map_start, *efi_map_end, *p;
    efi_memory_desc_t *md;
    u64 efi_desc_size;
    int pal_code_count = 0;
    u64 vaddr, mask;

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

    for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) {
        md = p;
        if (md->type != EFI_PAL_CODE)
            continue;

        if (++pal_code_count > 1) {
            printk(KERN_ERR "Too many EFI Pal Code memory ranges, "
                   "dropped @ %llx\n", md->phys_addr);
            continue;
        }
        /*
         * The only ITLB entry in region 7 that is used is the one
         * installed by __start().  That entry covers a 64MB range.
         */
        mask  = ~((1 << KERNEL_TR_PAGE_SHIFT) - 1);
        vaddr = PAGE_OFFSET + md->phys_addr;

        /*
         * We must check that the PAL mapping won't overlap with the
         * kernel mapping.
         *
         * PAL code is guaranteed to be aligned on a power of 2 between
         * 4k and 256KB and that only one ITR is needed to map it. This
         * implies that the PAL code is always aligned on its size,
         * i.e., the closest matching page size supported by the TLB.
         * Therefore PAL code is guaranteed never to cross a 64MB unless
         * it is bigger than 64MB (very unlikely!).  So for now the
         * following test is enough to determine whether or not we need
         * a dedicated ITR for the PAL code.
         */
        if ((vaddr & mask) == (KERNEL_START & mask)) {
            printk(KERN_INFO "%s: no need to install ITR for PAL code\n",
                   __func__);
            continue;
        }

        if (efi_md_size(md) > IA64_GRANULE_SIZE)
            panic("Whoa!  PAL code size bigger than a granule!");

#if EFI_DEBUG
        mask  = ~((1 << IA64_GRANULE_SHIFT) - 1);

        printk(KERN_INFO "CPU %d: mapping PAL code "
                       "[0x%lx-0x%lx) into [0x%lx-0x%lx)\n",
                       smp_processor_id(), md->phys_addr,
                       md->phys_addr + efi_md_size(md),
                       vaddr & mask, (vaddr & mask) + IA64_GRANULE_SIZE);
#endif
        return __va(md->phys_addr);
    }
    printk(KERN_WARNING "%s: no PAL-code memory-descriptor found\n",
           __func__);
    return NULL;
}


static u8 __init palo_checksum(u8 *buffer, u32 length)
{
    u8 sum = 0;
    u8 *end = buffer + length;

    while (buffer < end)
        sum = (u8) (sum + *(buffer++));

    return sum;
}

/*
 * Parse and handle PALO table which is published at:
 * http://www.dig64.org/home/DIG64_PALO_R1_0.pdf
 */
static void __init handle_palo(unsigned long palo_phys)
{
    struct palo_table *palo = __va(palo_phys);
    u8  checksum;

    if (strncmp(palo->signature, PALO_SIG, sizeof(PALO_SIG) - 1)) {
        printk(KERN_INFO "PALO signature incorrect.\n");
        return;
    }

    checksum = palo_checksum((u8 *)palo, palo->length);
    if (checksum) {
        printk(KERN_INFO "PALO checksum incorrect.\n");
        return;
    }

    setup_ptcg_sem(palo->max_tlb_purges, NPTCG_FROM_PALO);
}

void
efi_map_pal_code (void)
{
    void *pal_vaddr = efi_get_pal_addr ();
    u64 psr;

    if (!pal_vaddr)
        return;

    /*
     * Cannot write to CRx with PSR.ic=1
     */
    psr = ia64_clear_ic();
    ia64_itr(0x1, IA64_TR_PALCODE,
         GRANULEROUNDDOWN((unsigned long) pal_vaddr),
         pte_val(pfn_pte(__pa(pal_vaddr) >> PAGE_SHIFT, PAGE_KERNEL)),
         IA64_GRANULE_SHIFT);
    paravirt_dv_serialize_data();
    ia64_set_psr(psr);      /* restore psr */
}

void __init
efi_init (void)
{
    void *efi_map_start, *efi_map_end;
    efi_config_table_t *config_tables;
    efi_char16_t *c16;
    u64 efi_desc_size;
    char *cp, vendor[100] = "unknown";
    int i;
    unsigned long palo_phys;

    /*
     * It's too early to be able to use the standard kernel command line
     * support...
     */
    for (cp = boot_command_line; *cp; ) {
        if (memcmp(cp, "mem=", 4) == 0) {
            mem_limit = memparse(cp + 4, &cp);
        } else if (memcmp(cp, "max_addr=", 9) == 0) {
            max_addr = GRANULEROUNDDOWN(memparse(cp + 9, &cp));
        } else if (memcmp(cp, "min_addr=", 9) == 0) {
            min_addr = GRANULEROUNDDOWN(memparse(cp + 9, &cp));
        } else {
            while (*cp != ' ' && *cp)
                ++cp;
            while (*cp == ' ')
                ++cp;
        }
    }
    if (min_addr != 0UL)
        printk(KERN_INFO "Ignoring memory below %lluMB\n",
               min_addr >> 20);
    if (max_addr != ~0UL)
        printk(KERN_INFO "Ignoring memory above %lluMB\n",
               max_addr >> 20);

    efi.systab = __va(ia64_boot_param->efi_systab);

    /*
     * Verify the EFI Table
     */
    if (efi.systab == NULL)
        panic("Whoa! Can't find EFI system table.\n");
    if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
        panic("Whoa! EFI system table signature incorrect\n");
    if ((efi.systab->hdr.revision >> 16) == 0)
        printk(KERN_WARNING "Warning: EFI system table version "
               "%d.%02d, expected 1.00 or greater\n",
               efi.systab->hdr.revision >> 16,
               efi.systab->hdr.revision & 0xffff);

    config_tables = __va(efi.systab->tables);

    /* Show what we know for posterity */
    c16 = __va(efi.systab->fw_vendor);
    if (c16) {
        for (i = 0;i < (int) sizeof(vendor) - 1 && *c16; ++i)
            vendor[i] = *c16++;
        vendor[i] = '\0';
    }

    printk(KERN_INFO "EFI v%u.%.02u by %s:",
           efi.systab->hdr.revision >> 16,
           efi.systab->hdr.revision & 0xffff, vendor);

    efi.mps        = EFI_INVALID_TABLE_ADDR;
    efi.acpi       = EFI_INVALID_TABLE_ADDR;
    efi.acpi20     = EFI_INVALID_TABLE_ADDR;
    efi.smbios     = EFI_INVALID_TABLE_ADDR;
    efi.sal_systab = EFI_INVALID_TABLE_ADDR;
    efi.boot_info  = EFI_INVALID_TABLE_ADDR;
    efi.hcdp       = EFI_INVALID_TABLE_ADDR;
    efi.uga        = EFI_INVALID_TABLE_ADDR;

    palo_phys      = EFI_INVALID_TABLE_ADDR;

    for (i = 0; i < (int) efi.systab->nr_tables; i++) {
        if (efi_guidcmp(config_tables[i].guid, MPS_TABLE_GUID) == 0) {
            efi.mps = config_tables[i].table;
            printk(" MPS=0x%lx", config_tables[i].table);
        } else if (efi_guidcmp(config_tables[i].guid, ACPI_20_TABLE_GUID) == 0) {
            efi.acpi20 = config_tables[i].table;
            printk(" ACPI 2.0=0x%lx", config_tables[i].table);
        } else if (efi_guidcmp(config_tables[i].guid, ACPI_TABLE_GUID) == 0) {
            efi.acpi = config_tables[i].table;
            printk(" ACPI=0x%lx", config_tables[i].table);
        } else if (efi_guidcmp(config_tables[i].guid, SMBIOS_TABLE_GUID) == 0) {
            efi.smbios = config_tables[i].table;
            printk(" SMBIOS=0x%lx", config_tables[i].table);
        } else if (efi_guidcmp(config_tables[i].guid, SAL_SYSTEM_TABLE_GUID) == 0) {
            efi.sal_systab = config_tables[i].table;
            printk(" SALsystab=0x%lx", config_tables[i].table);
        } else if (efi_guidcmp(config_tables[i].guid, HCDP_TABLE_GUID) == 0) {
            efi.hcdp = config_tables[i].table;
            printk(" HCDP=0x%lx", config_tables[i].table);
        } else if (efi_guidcmp(config_tables[i].guid,
             PROCESSOR_ABSTRACTION_LAYER_OVERWRITE_GUID) == 0) {
            palo_phys = config_tables[i].table;
            printk(" PALO=0x%lx", config_tables[i].table);
        }
    }
    printk("\n");

    if (palo_phys != EFI_INVALID_TABLE_ADDR)
        handle_palo(palo_phys);

    runtime = __va(efi.systab->runtime);
    efi.get_time = phys_get_time;
    efi.set_time = phys_set_time;
    efi.get_wakeup_time = phys_get_wakeup_time;
    efi.set_wakeup_time = phys_set_wakeup_time;
    efi.get_variable = phys_get_variable;
    efi.get_next_variable = phys_get_next_variable;
    efi.set_variable = phys_set_variable;
    efi.get_next_high_mono_count = phys_get_next_high_mono_count;
    efi.reset_system = phys_reset_system;

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

#if EFI_DEBUG
    /* print EFI memory map: */
    {
        efi_memory_desc_t *md;
        void *p;

        for (i = 0, p = efi_map_start; p < efi_map_end;
             ++i, p += efi_desc_size)
        {
            const char *unit;
            unsigned long size;

            md = p;
            size = md->num_pages << EFI_PAGE_SHIFT;

            if ((size >> 40) > 0) {
                size >>= 40;
                unit = "TB";
            } else if ((size >> 30) > 0) {
                size >>= 30;
                unit = "GB";
            } else if ((size >> 20) > 0) {
                size >>= 20;
                unit = "MB";
            } else {
                size >>= 10;
                unit = "KB";
            }

            printk("mem%02d: type=%2u, attr=0x%016lx, "
                   "range=[0x%016lx-0x%016lx) (%4lu%s)\n",
                   i, md->type, md->attribute, md->phys_addr,
                   md->phys_addr + efi_md_size(md), size, unit);
        }
    }
#endif

    efi_map_pal_code();
    efi_enter_virtual_mode();
}

void
efi_enter_virtual_mode (void)
{
    void *efi_map_start, *efi_map_end, *p;
    efi_memory_desc_t *md;
    efi_status_t status;
    u64 efi_desc_size;

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

    for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) {
        md = p;
        if (md->attribute & EFI_MEMORY_RUNTIME) {
            /*
             * Some descriptors have multiple bits set, so the
             * order of the tests is relevant.
             */
            if (md->attribute & EFI_MEMORY_WB) {
                md->virt_addr = (u64) __va(md->phys_addr);
            } else if (md->attribute & EFI_MEMORY_UC) {
                md->virt_addr = (u64) ioremap(md->phys_addr, 0);
            } else if (md->attribute & EFI_MEMORY_WC) {
#if 0
                md->virt_addr = ia64_remap(md->phys_addr,
                               (_PAGE_A |
                                _PAGE_P |
                                _PAGE_D |
                                _PAGE_MA_WC |
                                _PAGE_PL_0 |
                                _PAGE_AR_RW));
#else
                printk(KERN_INFO "EFI_MEMORY_WC mapping\n");
                md->virt_addr = (u64) ioremap(md->phys_addr, 0);
#endif
            } else if (md->attribute & EFI_MEMORY_WT) {
#if 0
                md->virt_addr = ia64_remap(md->phys_addr,
                               (_PAGE_A |
                                _PAGE_P |
                                _PAGE_D |
                                _PAGE_MA_WT |
                                _PAGE_PL_0 |
                                _PAGE_AR_RW));
#else
                printk(KERN_INFO "EFI_MEMORY_WT mapping\n");
                md->virt_addr = (u64) ioremap(md->phys_addr, 0);
#endif
            }
        }
    }

    status = efi_call_phys(__va(runtime->set_virtual_address_map),
                   ia64_boot_param->efi_memmap_size,
                   efi_desc_size,
                   ia64_boot_param->efi_memdesc_version,
                   ia64_boot_param->efi_memmap);
    if (status != EFI_SUCCESS) {
        printk(KERN_WARNING "warning: unable to switch EFI into "
               "virtual mode (status=%lu)\n", status);
        return;
    }

    /*
     * Now that EFI is in virtual mode, we call the EFI functions more
     * efficiently:
     */
    efi.get_time = virt_get_time;
    efi.set_time = virt_set_time;
    efi.get_wakeup_time = virt_get_wakeup_time;
    efi.set_wakeup_time = virt_set_wakeup_time;
    efi.get_variable = virt_get_variable;
    efi.get_next_variable = virt_get_next_variable;
    efi.set_variable = virt_set_variable;
    efi.get_next_high_mono_count = virt_get_next_high_mono_count;
    efi.reset_system = virt_reset_system;
}

/*
 * Walk the EFI memory map looking for the I/O port range.  There can only be
 * one entry of this type, other I/O port ranges should be described via ACPI.
 */
u64
efi_get_iobase (void)
{
    void *efi_map_start, *efi_map_end, *p;
    efi_memory_desc_t *md;
    u64 efi_desc_size;

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

    for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) {
        md = p;
        if (md->type == EFI_MEMORY_MAPPED_IO_PORT_SPACE) {
            if (md->attribute & EFI_MEMORY_UC)
                return md->phys_addr;
        }
    }
    return 0;
}

static struct kern_memdesc *
kern_memory_descriptor (unsigned long phys_addr)
{
    struct kern_memdesc *md;

    for (md = kern_memmap; md->start != ~0UL; md++) {
        if (phys_addr - md->start < (md->num_pages << EFI_PAGE_SHIFT))
             return md;
    }
    return NULL;
}

static efi_memory_desc_t *
efi_memory_descriptor (unsigned long phys_addr)
{
    void *efi_map_start, *efi_map_end, *p;
    efi_memory_desc_t *md;
    u64 efi_desc_size;

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

    for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) {
        md = p;

        if (phys_addr - md->phys_addr < efi_md_size(md))
             return md;
    }
    return NULL;
}

static int
efi_memmap_intersects (unsigned long phys_addr, unsigned long size)
{
    void *efi_map_start, *efi_map_end, *p;
    efi_memory_desc_t *md;
    u64 efi_desc_size;
    unsigned long end;

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

    end = phys_addr + size;

    for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) {
        md = p;
        if (md->phys_addr < end && efi_md_end(md) > phys_addr)
            return 1;
    }
    return 0;
}

u32
efi_mem_type (unsigned long phys_addr)
{
    efi_memory_desc_t *md = efi_memory_descriptor(phys_addr);

    if (md)
        return md->type;
    return 0;
}

u64
efi_mem_attributes (unsigned long phys_addr)
{
    efi_memory_desc_t *md = efi_memory_descriptor(phys_addr);

    if (md)
        return md->attribute;
    return 0;
}
EXPORT_SYMBOL(efi_mem_attributes);

u64
efi_mem_attribute (unsigned long phys_addr, unsigned long size)
{
    unsigned long end = phys_addr + size;
    efi_memory_desc_t *md = efi_memory_descriptor(phys_addr);
    u64 attr;

    if (!md)
        return 0;

    /*
     * EFI_MEMORY_RUNTIME is not a memory attribute; it just tells
     * the kernel that firmware needs this region mapped.
     */
    attr = md->attribute & ~EFI_MEMORY_RUNTIME;
    do {
        unsigned long md_end = efi_md_end(md);

        if (end <= md_end)
            return attr;

        md = efi_memory_descriptor(md_end);
        if (!md || (md->attribute & ~EFI_MEMORY_RUNTIME) != attr)
            return 0;
    } while (md);
    return 0;   /* never reached */
}

u64
kern_mem_attribute (unsigned long phys_addr, unsigned long size)
{
    unsigned long end = phys_addr + size;
    struct kern_memdesc *md;
    u64 attr;

    /*
     * This is a hack for ioremap calls before we set up kern_memmap.
     * Maybe we should do efi_memmap_init() earlier instead.
     */
    if (!kern_memmap) {
        attr = efi_mem_attribute(phys_addr, size);
        if (attr & EFI_MEMORY_WB)
            return EFI_MEMORY_WB;
        return 0;
    }

    md = kern_memory_descriptor(phys_addr);
    if (!md)
        return 0;

    attr = md->attribute;
    do {
        unsigned long md_end = kmd_end(md);

        if (end <= md_end)
            return attr;

        md = kern_memory_descriptor(md_end);
        if (!md || md->attribute != attr)
            return 0;
    } while (md);
    return 0;   /* never reached */
}
EXPORT_SYMBOL(kern_mem_attribute);

int
valid_phys_addr_range (unsigned long phys_addr, unsigned long size)
{
    u64 attr;

    /*
     * /dev/mem reads and writes use copy_to_user(), which implicitly
     * uses a granule-sized kernel identity mapping.  It's really
     * only safe to do this for regions in kern_memmap.  For more
     * details, see Documentation/ia64/aliasing.txt.
     */
    attr = kern_mem_attribute(phys_addr, size);
    if (attr & EFI_MEMORY_WB || attr & EFI_MEMORY_UC)
        return 1;
    return 0;
}

int
valid_mmap_phys_addr_range (unsigned long pfn, unsigned long size)
{
    unsigned long phys_addr = pfn << PAGE_SHIFT;
    u64 attr;

    attr = efi_mem_attribute(phys_addr, size);

    /*
     * /dev/mem mmap uses normal user pages, so we don't need the entire
     * granule, but the entire region we're mapping must support the same
     * attribute.
     */
    if (attr & EFI_MEMORY_WB || attr & EFI_MEMORY_UC)
        return 1;

    /*
     * Intel firmware doesn't tell us about all the MMIO regions, so
     * in general we have to allow mmap requests.  But if EFI *does*
     * tell us about anything inside this region, we should deny it.
     * The user can always map a smaller region to avoid the overlap.
     */
    if (efi_memmap_intersects(phys_addr, size))
        return 0;

    return 1;
}

pgprot_t
phys_mem_access_prot(struct file *file, unsigned long pfn, unsigned long size,
             pgprot_t vma_prot)
{
    unsigned long phys_addr = pfn << PAGE_SHIFT;
    u64 attr;

    /*
     * For /dev/mem mmap, we use user mappings, but if the region is
     * in kern_memmap (and hence may be covered by a kernel mapping),
     * we must use the same attribute as the kernel mapping.
     */
    attr = kern_mem_attribute(phys_addr, size);
    if (attr & EFI_MEMORY_WB)
        return pgprot_cacheable(vma_prot);
    else if (attr & EFI_MEMORY_UC)
        return pgprot_noncached(vma_prot);

    /*
     * Some chipsets don't support UC access to memory.  If
     * WB is supported, we prefer that.
     */
    if (efi_mem_attribute(phys_addr, size) & EFI_MEMORY_WB)
        return pgprot_cacheable(vma_prot);

    return pgprot_noncached(vma_prot);
}

int __init
efi_uart_console_only(void)
{
    efi_status_t status;
    char *s, name[] = "ConOut";
    efi_guid_t guid = EFI_GLOBAL_VARIABLE_GUID;
    efi_char16_t *utf16, name_utf16[32];
    unsigned char data[1024];
    unsigned long size = sizeof(data);
    struct efi_generic_dev_path *hdr, *end_addr;
    int uart = 0;

    /* Convert to UTF-16 */
    utf16 = name_utf16;
    s = name;
    while (*s)
        *utf16++ = *s++ & 0x7f;
    *utf16 = 0;

    status = efi.get_variable(name_utf16, &guid, NULL, &size, data);
    if (status != EFI_SUCCESS) {
        printk(KERN_ERR "No EFI %s variable?\n", name);
        return 0;
    }

    hdr = (struct efi_generic_dev_path *) data;
    end_addr = (struct efi_generic_dev_path *) ((u8 *) data + size);
    while (hdr < end_addr) {
        if (hdr->type == EFI_DEV_MSG &&
            hdr->sub_type == EFI_DEV_MSG_UART)
            uart = 1;
        else if (hdr->type == EFI_DEV_END_PATH ||
              hdr->type == EFI_DEV_END_PATH2) {
            if (!uart)
                return 0;
            if (hdr->sub_type == EFI_DEV_END_ENTIRE)
                return 1;
            uart = 0;
        }
        hdr = (struct efi_generic_dev_path *)((u8 *) hdr + hdr->length);
    }
    printk(KERN_ERR "Malformed %s value\n", name);
    return 0;
}

/*
 * Look for the first granule aligned memory descriptor memory
 * that is big enough to hold EFI memory map. Make sure this
 * descriptor is atleast granule sized so it does not get trimmed
 */
struct kern_memdesc *
find_memmap_space (void)
{
    u64 contig_low=0, contig_high=0;
    u64 as = 0, ae;
    void *efi_map_start, *efi_map_end, *p, *q;
    efi_memory_desc_t *md, *pmd = NULL, *check_md;
    u64 space_needed, efi_desc_size;
    unsigned long total_mem = 0;

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

    /*
     * Worst case: we need 3 kernel descriptors for each efi descriptor
     * (if every entry has a WB part in the middle, and UC head and tail),
     * plus one for the end marker.
     */
    space_needed = sizeof(kern_memdesc_t) *
        (3 * (ia64_boot_param->efi_memmap_size/efi_desc_size) + 1);

    for (p = efi_map_start; p < efi_map_end; pmd = md, p += efi_desc_size) {
        md = p;
        if (!efi_wb(md)) {
            continue;
        }
        if (pmd == NULL || !efi_wb(pmd) ||
            efi_md_end(pmd) != md->phys_addr) {
            contig_low = GRANULEROUNDUP(md->phys_addr);
            contig_high = efi_md_end(md);
            for (q = p + efi_desc_size; q < efi_map_end;
                 q += efi_desc_size) {
                check_md = q;
                if (!efi_wb(check_md))
                    break;
                if (contig_high != check_md->phys_addr)
                    break;
                contig_high = efi_md_end(check_md);
            }
            contig_high = GRANULEROUNDDOWN(contig_high);
        }
        if (!is_memory_available(md) || md->type == EFI_LOADER_DATA)
            continue;

        /* Round ends inward to granule boundaries */
        as = max(contig_low, md->phys_addr);
        ae = min(contig_high, efi_md_end(md));

        /* keep within max_addr= and min_addr= command line arg */
        as = max(as, min_addr);
        ae = min(ae, max_addr);
        if (ae <= as)
            continue;

        /* avoid going over mem= command line arg */
        if (total_mem + (ae - as) > mem_limit)
            ae -= total_mem + (ae - as) - mem_limit;

        if (ae <= as)
            continue;

        if (ae - as > space_needed)
            break;
    }
    if (p >= efi_map_end)
        panic("Can't allocate space for kernel memory descriptors");

    return __va(as);
}

/*
 * Walk the EFI memory map and gather all memory available for kernel
 * to use.  We can allocate partial granules only if the unavailable
 * parts exist, and are WB.
 */
unsigned long
efi_memmap_init(u64 *s, u64 *e)
{
    struct kern_memdesc *k, *prev = NULL;
    u64 contig_low=0, contig_high=0;
    u64 as, ae, lim;
    void *efi_map_start, *efi_map_end, *p, *q;
    efi_memory_desc_t *md, *pmd = NULL, *check_md;
    u64 efi_desc_size;
    unsigned long total_mem = 0;

    k = kern_memmap = find_memmap_space();

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

    for (p = efi_map_start; p < efi_map_end; pmd = md, p += efi_desc_size) {
        md = p;
        if (!efi_wb(md)) {
            if (efi_uc(md) &&
                (md->type == EFI_CONVENTIONAL_MEMORY ||
                 md->type == EFI_BOOT_SERVICES_DATA)) {
                k->attribute = EFI_MEMORY_UC;
                k->start = md->phys_addr;
                k->num_pages = md->num_pages;
                k++;
            }
            continue;
        }
        if (pmd == NULL || !efi_wb(pmd) ||
            efi_md_end(pmd) != md->phys_addr) {
            contig_low = GRANULEROUNDUP(md->phys_addr);
            contig_high = efi_md_end(md);
            for (q = p + efi_desc_size; q < efi_map_end;
                 q += efi_desc_size) {
                check_md = q;
                if (!efi_wb(check_md))
                    break;
                if (contig_high != check_md->phys_addr)
                    break;
                contig_high = efi_md_end(check_md);
            }
            contig_high = GRANULEROUNDDOWN(contig_high);
        }
        if (!is_memory_available(md))
            continue;

#ifdef CONFIG_CRASH_DUMP
        /* saved_max_pfn should ignore max_addr= command line arg */
        if (saved_max_pfn < (efi_md_end(md) >> PAGE_SHIFT))
            saved_max_pfn = (efi_md_end(md) >> PAGE_SHIFT);
#endif
        /*
         * Round ends inward to granule boundaries
         * Give trimmings to uncached allocator
         */
        if (md->phys_addr < contig_low) {
            lim = min(efi_md_end(md), contig_low);
            if (efi_uc(md)) {
                if (k > kern_memmap &&
                    (k-1)->attribute == EFI_MEMORY_UC &&
                    kmd_end(k-1) == md->phys_addr) {
                    (k-1)->num_pages +=
                        (lim - md->phys_addr)
                        >> EFI_PAGE_SHIFT;
                } else {
                    k->attribute = EFI_MEMORY_UC;
                    k->start = md->phys_addr;
                    k->num_pages = (lim - md->phys_addr)
                        >> EFI_PAGE_SHIFT;
                    k++;
                }
            }
            as = contig_low;
        } else
            as = md->phys_addr;

        if (efi_md_end(md) > contig_high) {
            lim = max(md->phys_addr, contig_high);
            if (efi_uc(md)) {
                if (lim == md->phys_addr && k > kern_memmap &&
                    (k-1)->attribute == EFI_MEMORY_UC &&
                    kmd_end(k-1) == md->phys_addr) {
                    (k-1)->num_pages += md->num_pages;
                } else {
                    k->attribute = EFI_MEMORY_UC;
                    k->start = lim;
                    k->num_pages = (efi_md_end(md) - lim)
                        >> EFI_PAGE_SHIFT;
                    k++;
                }
            }
            ae = contig_high;
        } else
            ae = efi_md_end(md);

        /* keep within max_addr= and min_addr= command line arg */
        as = max(as, min_addr);
        ae = min(ae, max_addr);
        if (ae <= as)
            continue;

        /* avoid going over mem= command line arg */
        if (total_mem + (ae - as) > mem_limit)
            ae -= total_mem + (ae - as) - mem_limit;

        if (ae <= as)
            continue;
        if (prev && kmd_end(prev) == md->phys_addr) {
            prev->num_pages += (ae - as) >> EFI_PAGE_SHIFT;
            total_mem += ae - as;
            continue;
        }
        k->attribute = EFI_MEMORY_WB;
        k->start = as;
        k->num_pages = (ae - as) >> EFI_PAGE_SHIFT;
        total_mem += ae - as;
        prev = k++;
    }
    k->start = ~0L; /* end-marker */

    /* reserve the memory we are using for kern_memmap */
    *s = (u64)kern_memmap;
    *e = (u64)++k;

    return total_mem;
}

void
efi_initialize_iomem_resources(struct resource *code_resource,
                   struct resource *data_resource,
                   struct resource *bss_resource)
{
    struct resource *res;
    void *efi_map_start, *efi_map_end, *p;
    efi_memory_desc_t *md;
    u64 efi_desc_size;
    char *name;
    unsigned long flags;

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

    res = NULL;

    for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) {
        md = p;

        if (md->num_pages == 0) /* should not happen */
            continue;

        flags = IORESOURCE_MEM | IORESOURCE_BUSY;
        switch (md->type) {

            case EFI_MEMORY_MAPPED_IO:
            case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
                continue;

            case EFI_LOADER_CODE:
            case EFI_LOADER_DATA:
            case EFI_BOOT_SERVICES_DATA:
            case EFI_BOOT_SERVICES_CODE:
            case EFI_CONVENTIONAL_MEMORY:
                if (md->attribute & EFI_MEMORY_WP) {
                    name = "System ROM";
                    flags |= IORESOURCE_READONLY;
                } else if (md->attribute == EFI_MEMORY_UC)
                    name = "Uncached RAM";
                else
                    name = "System RAM";
                break;

            case EFI_ACPI_MEMORY_NVS:
                name = "ACPI Non-volatile Storage";
                break;

            case EFI_UNUSABLE_MEMORY:
                name = "reserved";
                flags |= IORESOURCE_DISABLED;
                break;

            case EFI_RESERVED_TYPE:
            case EFI_RUNTIME_SERVICES_CODE:
            case EFI_RUNTIME_SERVICES_DATA:
            case EFI_ACPI_RECLAIM_MEMORY:
            default:
                name = "reserved";
                break;
        }

        if ((res = kzalloc(sizeof(struct resource),
                   GFP_KERNEL)) == NULL) {
            printk(KERN_ERR
                   "failed to allocate resource for iomem\n");
            return;
        }

        res->name = name;
        res->start = md->phys_addr;
        res->end = md->phys_addr + efi_md_size(md) - 1;
        res->flags = flags;

        if (insert_resource(&iomem_resource, res) < 0)
            kfree(res);
        else {
            /*
             * We don't know which region contains
             * kernel data so we try it repeatedly and
             * let the resource manager test it.
             */
            insert_resource(res, code_resource);
            insert_resource(res, data_resource);
            insert_resource(res, bss_resource);
#ifdef CONFIG_KEXEC
                        insert_resource(res, &efi_memmap_res);
                        insert_resource(res, &boot_param_res);
            if (crashk_res.end > crashk_res.start)
                insert_resource(res, &crashk_res);
#endif
        }
    }
}

#ifdef CONFIG_KEXEC
/* find a block of memory aligned to 64M exclude reserved regions
   rsvd_regions are sorted
 */
unsigned long __init
kdump_find_rsvd_region (unsigned long size, struct rsvd_region *r, int n)
{
    int i;
    u64 start, end;
    u64 alignment = 1UL << _PAGE_SIZE_64M;
    void *efi_map_start, *efi_map_end, *p;
    efi_memory_desc_t *md;
    u64 efi_desc_size;

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

    for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) {
        md = p;
        if (!efi_wb(md))
            continue;
        start = ALIGN(md->phys_addr, alignment);
        end = efi_md_end(md);
        for (i = 0; i < n; i++) {
            if (__pa(r[i].start) >= start && __pa(r[i].end) < end) {
                if (__pa(r[i].start) > start + size)
                    return start;
                start = ALIGN(__pa(r[i].end), alignment);
                if (i < n-1 &&
                    __pa(r[i+1].start) < start + size)
                    continue;
                else
                    break;
            }
        }
        if (end > start + size)
            return start;
    }

    printk(KERN_WARNING
           "Cannot reserve 0x%lx byte of memory for crashdump\n", size);
    return ~0UL;
}
#endif

#ifdef CONFIG_CRASH_DUMP
/* locate the size find a the descriptor at a certain address */
unsigned long __init
vmcore_find_descriptor_size (unsigned long address)
{
    void *efi_map_start, *efi_map_end, *p;
    efi_memory_desc_t *md;
    u64 efi_desc_size;
    unsigned long ret = 0;

    efi_map_start = __va(ia64_boot_param->efi_memmap);
    efi_map_end   = efi_map_start + ia64_boot_param->efi_memmap_size;
    efi_desc_size = ia64_boot_param->efi_memdesc_size;

    for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) {
        md = p;
        if (efi_wb(md) && md->type == EFI_LOADER_DATA
            && md->phys_addr == address) {
            ret = efi_md_size(md);
            break;
        }
    }

    if (ret == 0)
        printk(KERN_WARNING "Cannot locate EFI vmcore descriptor\n");

    return ret;
}
#endif