mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race

[linux/fpc-iii.git] / arch / tile / kernel / setup.c

/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 */

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mmzone.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <linux/node.h>
#include <linux/cpu.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/kexec.h>
#include <linux/pci.h>
#include <linux/swiotlb.h>
#include <linux/initrd.h>
#include <linux/io.h>
#include <linux/highmem.h>
#include <linux/smp.h>
#include <linux/timex.h>
#include <linux/hugetlb.h>
#include <linux/start_kernel.h>
#include <linux/screen_info.h>
#include <linux/tick.h>
#include <asm/setup.h>
#include <asm/sections.h>
#include <asm/cacheflush.h>
#include <asm/pgalloc.h>
#include <asm/mmu_context.h>
#include <hv/hypervisor.h>
#include <arch/interrupts.h>

/* <linux/smp.h> doesn't provide this definition. */
#ifndef CONFIG_SMP
#define setup_max_cpus 1
#endif

static inline int ABS(int x) { return x >= 0 ? x : -x; }

/* Chip information */
char chip_model[64] __ro_after_init;

#ifdef CONFIG_VT
struct screen_info screen_info;
#endif

struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
EXPORT_SYMBOL(node_data);

/* Information on the NUMA nodes that we compute early */
unsigned long node_start_pfn[MAX_NUMNODES];
unsigned long node_end_pfn[MAX_NUMNODES];
unsigned long __initdata node_memmap_pfn[MAX_NUMNODES];
unsigned long __initdata node_percpu_pfn[MAX_NUMNODES];
unsigned long __initdata node_free_pfn[MAX_NUMNODES];

static unsigned long __initdata node_percpu[MAX_NUMNODES];

/*
 * per-CPU stack and boot info.
 */
DEFINE_PER_CPU(unsigned long, boot_sp) =
        (unsigned long)init_stack + THREAD_SIZE - STACK_TOP_DELTA;

#ifdef CONFIG_SMP
DEFINE_PER_CPU(unsigned long, boot_pc) = (unsigned long)start_kernel;
#else
/*
 * The variable must be __initdata since it references __init code.
 * With CONFIG_SMP it is per-cpu data, which is exempt from validation.
 */
unsigned long __initdata boot_pc = (unsigned long)start_kernel;
#endif

#ifdef CONFIG_HIGHMEM
/* Page frame index of end of lowmem on each controller. */
unsigned long node_lowmem_end_pfn[MAX_NUMNODES];

/* Number of pages that can be mapped into lowmem. */
static unsigned long __initdata mappable_physpages;
#endif

/* Data on which physical memory controller corresponds to which NUMA node */
int node_controller[MAX_NUMNODES] = { [0 ... MAX_NUMNODES-1] = -1 };

#ifdef CONFIG_HIGHMEM
/* Map information from VAs to PAs */
unsigned long pbase_map[1 << (32 - HPAGE_SHIFT)]
  __ro_after_init __attribute__((aligned(L2_CACHE_BYTES)));
EXPORT_SYMBOL(pbase_map);

/* Map information from PAs to VAs */
void *vbase_map[NR_PA_HIGHBIT_VALUES]
  __ro_after_init __attribute__((aligned(L2_CACHE_BYTES)));
EXPORT_SYMBOL(vbase_map);
#endif

/* Node number as a function of the high PA bits */
int highbits_to_node[NR_PA_HIGHBIT_VALUES] __ro_after_init;
EXPORT_SYMBOL(highbits_to_node);

static unsigned int __initdata maxmem_pfn = -1U;
static unsigned int __initdata maxnodemem_pfn[MAX_NUMNODES] = {
        [0 ... MAX_NUMNODES-1] = -1U
};
static nodemask_t __initdata isolnodes;

#if defined(CONFIG_PCI) && !defined(__tilegx__)
enum { DEFAULT_PCI_RESERVE_MB = 64 };
static unsigned int __initdata pci_reserve_mb = DEFAULT_PCI_RESERVE_MB;
unsigned long __initdata pci_reserve_start_pfn = -1U;
unsigned long __initdata pci_reserve_end_pfn = -1U;
#endif

static int __init setup_maxmem(char *str)
{
        unsigned long long maxmem;
        if (str == NULL || (maxmem = memparse(str, NULL)) == 0)
                return -EINVAL;

        maxmem_pfn = (maxmem >> HPAGE_SHIFT) << (HPAGE_SHIFT - PAGE_SHIFT);
        pr_info("Forcing RAM used to no more than %dMB\n",
                maxmem_pfn >> (20 - PAGE_SHIFT));
        return 0;
}
early_param("maxmem", setup_maxmem);

static int __init setup_maxnodemem(char *str)
{
        char *endp;
        unsigned long long maxnodemem;
        unsigned long node;

        node = str ? simple_strtoul(str, &endp, 0) : INT_MAX;
        if (node >= MAX_NUMNODES || *endp != ':')
                return -EINVAL;

        maxnodemem = memparse(endp+1, NULL);
        maxnodemem_pfn[node] = (maxnodemem >> HPAGE_SHIFT) <<
                (HPAGE_SHIFT - PAGE_SHIFT);
        pr_info("Forcing RAM used on node %ld to no more than %dMB\n",
                node, maxnodemem_pfn[node] >> (20 - PAGE_SHIFT));
        return 0;
}
early_param("maxnodemem", setup_maxnodemem);

struct memmap_entry {
        u64 addr;       /* start of memory segment */
        u64 size;       /* size of memory segment */
};
static struct memmap_entry memmap_map[64];
static int memmap_nr;

static void add_memmap_region(u64 addr, u64 size)
{
        if (memmap_nr >= ARRAY_SIZE(memmap_map)) {
                pr_err("Ooops! Too many entries in the memory map!\n");
                return;
        }
        memmap_map[memmap_nr].addr = addr;
        memmap_map[memmap_nr].size = size;
        memmap_nr++;
}

static int __init setup_memmap(char *p)
{
        char *oldp;
        u64 start_at, mem_size;

        if (!p)
                return -EINVAL;

        if (!strncmp(p, "exactmap", 8)) {
                pr_err("\"memmap=exactmap\" not valid on tile\n");
                return 0;
        }

        oldp = p;
        mem_size = memparse(p, &p);
        if (p == oldp)
                return -EINVAL;

        if (*p == '@') {
                pr_err("\"memmap=nn@ss\" (force RAM) invalid on tile\n");
        } else if (*p == '#') {
                pr_err("\"memmap=nn#ss\" (force ACPI data) invalid on tile\n");
        } else if (*p == '$') {
                start_at = memparse(p+1, &p);
                add_memmap_region(start_at, mem_size);
        } else {
                if (mem_size == 0)
                        return -EINVAL;
                maxmem_pfn = (mem_size >> HPAGE_SHIFT) <<
                        (HPAGE_SHIFT - PAGE_SHIFT);
        }
        return *p == '\0' ? 0 : -EINVAL;
}
early_param("memmap", setup_memmap);

static int __init setup_mem(char *str)
{
        return setup_maxmem(str);
}
early_param("mem", setup_mem);  /* compatibility with x86 */

static int __init setup_isolnodes(char *str)
{
        if (str == NULL || nodelist_parse(str, isolnodes) != 0)
                return -EINVAL;

        pr_info("Set isolnodes value to '%*pbl'\n",
                nodemask_pr_args(&isolnodes));
        return 0;
}
early_param("isolnodes", setup_isolnodes);

#if defined(CONFIG_PCI) && !defined(__tilegx__)
static int __init setup_pci_reserve(char* str)
{
        if (str == NULL || kstrtouint(str, 0, &pci_reserve_mb) != 0 ||
            pci_reserve_mb > 3 * 1024)
                return -EINVAL;

        pr_info("Reserving %dMB for PCIE root complex mappings\n",
                pci_reserve_mb);
        return 0;
}
early_param("pci_reserve", setup_pci_reserve);
#endif

#ifndef __tilegx__
/*
 * vmalloc=size forces the vmalloc area to be exactly 'size' bytes.
 * This can be used to increase (or decrease) the vmalloc area.
 */
static int __init parse_vmalloc(char *arg)
{
        if (!arg)
                return -EINVAL;

        VMALLOC_RESERVE = (memparse(arg, &arg) + PGDIR_SIZE - 1) & PGDIR_MASK;

        /* See validate_va() for more on this test. */
        if ((long)_VMALLOC_START >= 0)
                early_panic("\"vmalloc=%#lx\" value too large: maximum %#lx\n",
                            VMALLOC_RESERVE, _VMALLOC_END - 0x80000000UL);

        return 0;
}
early_param("vmalloc", parse_vmalloc);
#endif

#ifdef CONFIG_HIGHMEM
/*
 * Determine for each controller where its lowmem is mapped and how much of
 * it is mapped there.  On controller zero, the first few megabytes are
 * already mapped in as code at MEM_SV_START, so in principle we could
 * start our data mappings higher up, but for now we don't bother, to avoid
 * additional confusion.
 *
 * One question is whether, on systems with more than 768 Mb and
 * controllers of different sizes, to map in a proportionate amount of
 * each one, or to try to map the same amount from each controller.
 * (E.g. if we have three controllers with 256MB, 1GB, and 256MB
 * respectively, do we map 256MB from each, or do we map 128 MB, 512
 * MB, and 128 MB respectively?)  For now we use a proportionate
 * solution like the latter.
 *
 * The VA/PA mapping demands that we align our decisions at 16 MB
 * boundaries so that we can rapidly convert VA to PA.
 */
static void *__init setup_pa_va_mapping(void)
{
        unsigned long curr_pages = 0;
        unsigned long vaddr = PAGE_OFFSET;
        nodemask_t highonlynodes = isolnodes;
        int i, j;

        memset(pbase_map, -1, sizeof(pbase_map));
        memset(vbase_map, -1, sizeof(vbase_map));

        /* Node zero cannot be isolated for LOWMEM purposes. */
        node_clear(0, highonlynodes);

        /* Count up the number of pages on non-highonlynodes controllers. */
        mappable_physpages = 0;
        for_each_online_node(i) {
                if (!node_isset(i, highonlynodes))
                        mappable_physpages +=
                                node_end_pfn[i] - node_start_pfn[i];
        }

        for_each_online_node(i) {
                unsigned long start = node_start_pfn[i];
                unsigned long end = node_end_pfn[i];
                unsigned long size = end - start;
                unsigned long vaddr_end;

                if (node_isset(i, highonlynodes)) {
                        /* Mark this controller as having no lowmem. */
                        node_lowmem_end_pfn[i] = start;
                        continue;
                }

                curr_pages += size;
                if (mappable_physpages > MAXMEM_PFN) {
                        vaddr_end = PAGE_OFFSET +
                                (((u64)curr_pages * MAXMEM_PFN /
                                  mappable_physpages)
                                 << PAGE_SHIFT);
                } else {
                        vaddr_end = PAGE_OFFSET + (curr_pages << PAGE_SHIFT);
                }
                for (j = 0; vaddr < vaddr_end; vaddr += HPAGE_SIZE, ++j) {
                        unsigned long this_pfn =
                                start + (j << HUGETLB_PAGE_ORDER);
                        pbase_map[vaddr >> HPAGE_SHIFT] = this_pfn;
                        if (vbase_map[__pfn_to_highbits(this_pfn)] ==
                            (void *)-1)
                                vbase_map[__pfn_to_highbits(this_pfn)] =
                                        (void *)(vaddr & HPAGE_MASK);
                }
                node_lowmem_end_pfn[i] = start + (j << HUGETLB_PAGE_ORDER);
                BUG_ON(node_lowmem_end_pfn[i] > end);
        }

        /* Return highest address of any mapped memory. */
        return (void *)vaddr;
}
#endif /* CONFIG_HIGHMEM */

/*
 * Register our most important memory mappings with the debug stub.
 *
 * This is up to 4 mappings for lowmem, one mapping per memory
 * controller, plus one for our text segment.
 */
static void store_permanent_mappings(void)
{
        int i;

        for_each_online_node(i) {
                HV_PhysAddr pa = ((HV_PhysAddr)node_start_pfn[i]) << PAGE_SHIFT;
#ifdef CONFIG_HIGHMEM
                HV_PhysAddr high_mapped_pa = node_lowmem_end_pfn[i];
#else
                HV_PhysAddr high_mapped_pa = node_end_pfn[i];
#endif

                unsigned long pages = high_mapped_pa - node_start_pfn[i];
                HV_VirtAddr addr = (HV_VirtAddr) __va(pa);
                hv_store_mapping(addr, pages << PAGE_SHIFT, pa);
        }

        hv_store_mapping((HV_VirtAddr)_text,
                         (uint32_t)(_einittext - _text), 0);
}

/*
 * Use hv_inquire_physical() to populate node_{start,end}_pfn[]
 * and node_online_map, doing suitable sanity-checking.
 * Also set min_low_pfn, max_low_pfn, and max_pfn.
 */
static void __init setup_memory(void)
{
        int i, j;
        int highbits_seen[NR_PA_HIGHBIT_VALUES] = { 0 };
#ifdef CONFIG_HIGHMEM
        long highmem_pages;
#endif
#ifndef __tilegx__
        int cap;
#endif
#if defined(CONFIG_HIGHMEM) || defined(__tilegx__)
        long lowmem_pages;
#endif
        unsigned long physpages = 0;

        /* We are using a char to hold the cpu_2_node[] mapping */
        BUILD_BUG_ON(MAX_NUMNODES > 127);

        /* Discover the ranges of memory available to us */
        for (i = 0; ; ++i) {
                unsigned long start, size, end, highbits;
                HV_PhysAddrRange range = hv_inquire_physical(i);
                if (range.size == 0)
                        break;
#ifdef CONFIG_FLATMEM
                if (i > 0) {
                        pr_err("Can't use discontiguous PAs: %#llx..%#llx\n",
                               range.size, range.start + range.size);
                        continue;
                }
#endif
#ifndef __tilegx__
                if ((unsigned long)range.start) {
                        pr_err("Range not at 4GB multiple: %#llx..%#llx\n",
                               range.start, range.start + range.size);
                        continue;
                }
#endif
                if ((range.start & (HPAGE_SIZE-1)) != 0 ||
                    (range.size & (HPAGE_SIZE-1)) != 0) {
                        unsigned long long start_pa = range.start;
                        unsigned long long orig_size = range.size;
                        range.start = (start_pa + HPAGE_SIZE - 1) & HPAGE_MASK;
                        range.size -= (range.start - start_pa);
                        range.size &= HPAGE_MASK;
                        pr_err("Range not hugepage-aligned: %#llx..%#llx: now %#llx-%#llx\n",
                               start_pa, start_pa + orig_size,
                               range.start, range.start + range.size);
                }
                highbits = __pa_to_highbits(range.start);
                if (highbits >= NR_PA_HIGHBIT_VALUES) {
                        pr_err("PA high bits too high: %#llx..%#llx\n",
                               range.start, range.start + range.size);
                        continue;
                }
                if (highbits_seen[highbits]) {
                        pr_err("Range overlaps in high bits: %#llx..%#llx\n",
                               range.start, range.start + range.size);
                        continue;
                }
                highbits_seen[highbits] = 1;
                if (PFN_DOWN(range.size) > maxnodemem_pfn[i]) {
                        int max_size = maxnodemem_pfn[i];
                        if (max_size > 0) {
                                pr_err("Maxnodemem reduced node %d to %d pages\n",
                                       i, max_size);
                                range.size = PFN_PHYS(max_size);
                        } else {
                                pr_err("Maxnodemem disabled node %d\n", i);
                                continue;
                        }
                }
                if (physpages + PFN_DOWN(range.size) > maxmem_pfn) {
                        int max_size = maxmem_pfn - physpages;
                        if (max_size > 0) {
                                pr_err("Maxmem reduced node %d to %d pages\n",
                                       i, max_size);
                                range.size = PFN_PHYS(max_size);
                        } else {
                                pr_err("Maxmem disabled node %d\n", i);
                                continue;
                        }
                }
                if (i >= MAX_NUMNODES) {
                        pr_err("Too many PA nodes (#%d): %#llx...%#llx\n",
                               i, range.size, range.size + range.start);
                        continue;
                }

                start = range.start >> PAGE_SHIFT;
                size = range.size >> PAGE_SHIFT;
                end = start + size;

#ifndef __tilegx__
                if (((HV_PhysAddr)end << PAGE_SHIFT) !=
                    (range.start + range.size)) {
                        pr_err("PAs too high to represent: %#llx..%#llx\n",
                               range.start, range.start + range.size);
                        continue;
                }
#endif
#if defined(CONFIG_PCI) && !defined(__tilegx__)
                /*
                 * Blocks that overlap the pci reserved region must
                 * have enough space to hold the maximum percpu data
                 * region at the top of the range.  If there isn't
                 * enough space above the reserved region, just
                 * truncate the node.
                 */
                if (start <= pci_reserve_start_pfn &&
                    end > pci_reserve_start_pfn) {
                        unsigned int per_cpu_size =
                                __per_cpu_end - __per_cpu_start;
                        unsigned int percpu_pages =
                                NR_CPUS * (PFN_UP(per_cpu_size) >> PAGE_SHIFT);
                        if (end < pci_reserve_end_pfn + percpu_pages) {
                                end = pci_reserve_start_pfn;
                                pr_err("PCI mapping region reduced node %d to %ld pages\n",
                                       i, end - start);
                        }
                }
#endif

                for (j = __pfn_to_highbits(start);
                     j <= __pfn_to_highbits(end - 1); j++)
                        highbits_to_node[j] = i;

                node_start_pfn[i] = start;
                node_end_pfn[i] = end;
                node_controller[i] = range.controller;
                physpages += size;
                max_pfn = end;

                /* Mark node as online */
                node_set(i, node_online_map);
                node_set(i, node_possible_map);
        }

#ifndef __tilegx__
        /*
         * For 4KB pages, mem_map "struct page" data is 1% of the size
         * of the physical memory, so can be quite big (640 MB for
         * four 16G zones).  These structures must be mapped in
         * lowmem, and since we currently cap out at about 768 MB,
         * it's impractical to try to use this much address space.
         * For now, arbitrarily cap the amount of physical memory
         * we're willing to use at 8 million pages (32GB of 4KB pages).
         */
        cap = 8 * 1024 * 1024;  /* 8 million pages */
        if (physpages > cap) {
                int num_nodes = num_online_nodes();
                int cap_each = cap / num_nodes;
                unsigned long dropped_pages = 0;
                for (i = 0; i < num_nodes; ++i) {
                        int size = node_end_pfn[i] - node_start_pfn[i];
                        if (size > cap_each) {
                                dropped_pages += (size - cap_each);
                                node_end_pfn[i] = node_start_pfn[i] + cap_each;
                        }
                }
                physpages -= dropped_pages;
                pr_warn("Only using %ldMB memory - ignoring %ldMB\n",
                        physpages >> (20 - PAGE_SHIFT),
                        dropped_pages >> (20 - PAGE_SHIFT));
                pr_warn("Consider using a larger page size\n");
        }
#endif

        /* Heap starts just above the last loaded address. */
        min_low_pfn = PFN_UP((unsigned long)_end - PAGE_OFFSET);

#ifdef CONFIG_HIGHMEM
        /* Find where we map lowmem from each controller. */
        high_memory = setup_pa_va_mapping();

        /* Set max_low_pfn based on what node 0 can directly address. */
        max_low_pfn = node_lowmem_end_pfn[0];

        lowmem_pages = (mappable_physpages > MAXMEM_PFN) ?
                MAXMEM_PFN : mappable_physpages;
        highmem_pages = (long) (physpages - lowmem_pages);

        pr_notice("%ldMB HIGHMEM available\n",
                  pages_to_mb(highmem_pages > 0 ? highmem_pages : 0));
        pr_notice("%ldMB LOWMEM available\n", pages_to_mb(lowmem_pages));
#else
        /* Set max_low_pfn based on what node 0 can directly address. */
        max_low_pfn = node_end_pfn[0];

#ifndef __tilegx__
        if (node_end_pfn[0] > MAXMEM_PFN) {
                pr_warn("Only using %ldMB LOWMEM\n", MAXMEM >> 20);
                pr_warn("Use a HIGHMEM enabled kernel\n");
                max_low_pfn = MAXMEM_PFN;
                max_pfn = MAXMEM_PFN;
                node_end_pfn[0] = MAXMEM_PFN;
        } else {
                pr_notice("%ldMB memory available\n",
                          pages_to_mb(node_end_pfn[0]));
        }
        for (i = 1; i < MAX_NUMNODES; ++i) {
                node_start_pfn[i] = 0;
                node_end_pfn[i] = 0;
        }
        high_memory = __va(node_end_pfn[0]);
#else
        lowmem_pages = 0;
        for (i = 0; i < MAX_NUMNODES; ++i) {
                int pages = node_end_pfn[i] - node_start_pfn[i];
                lowmem_pages += pages;
                if (pages)
                        high_memory = pfn_to_kaddr(node_end_pfn[i]);
        }
        pr_notice("%ldMB memory available\n", pages_to_mb(lowmem_pages));
#endif
#endif
}

/*
 * On 32-bit machines, we only put bootmem on the low controller,
 * since PAs > 4GB can't be used in bootmem.  In principle one could
 * imagine, e.g., multiple 1 GB controllers all of which could support
 * bootmem, but in practice using controllers this small isn't a
 * particularly interesting scenario, so we just keep it simple and
 * use only the first controller for bootmem on 32-bit machines.
 */
static inline int node_has_bootmem(int nid)
{
#ifdef CONFIG_64BIT
        return 1;
#else
        return nid == 0;
#endif
}

static inline unsigned long alloc_bootmem_pfn(int nid,
                                              unsigned long size,
                                              unsigned long goal)
{
        void *kva = __alloc_bootmem_node(NODE_DATA(nid), size,
                                         PAGE_SIZE, goal);
        unsigned long pfn = kaddr_to_pfn(kva);
        BUG_ON(goal && PFN_PHYS(pfn) != goal);
        return pfn;
}

static void __init setup_bootmem_allocator_node(int i)
{
        unsigned long start, end, mapsize, mapstart;

        if (node_has_bootmem(i)) {
                NODE_DATA(i)->bdata = &bootmem_node_data[i];
        } else {
                /* Share controller zero's bdata for now. */
                NODE_DATA(i)->bdata = &bootmem_node_data[0];
                return;
        }

        /* Skip up to after the bss in node 0. */
        start = (i == 0) ? min_low_pfn : node_start_pfn[i];

        /* Only lowmem, if we're a HIGHMEM build. */
#ifdef CONFIG_HIGHMEM
        end = node_lowmem_end_pfn[i];
#else
        end = node_end_pfn[i];
#endif

        /* No memory here. */
        if (end == start)
                return;

        /* Figure out where the bootmem bitmap is located. */
        mapsize = bootmem_bootmap_pages(end - start);
        if (i == 0) {
                /* Use some space right before the heap on node 0. */
                mapstart = start;
                start += mapsize;
        } else {
                /* Allocate bitmap on node 0 to avoid page table issues. */
                mapstart = alloc_bootmem_pfn(0, PFN_PHYS(mapsize), 0);
        }

        /* Initialize a node. */
        init_bootmem_node(NODE_DATA(i), mapstart, start, end);

        /* Free all the space back into the allocator. */
        free_bootmem(PFN_PHYS(start), PFN_PHYS(end - start));

#if defined(CONFIG_PCI) && !defined(__tilegx__)
        /*
         * Throw away any memory aliased by the PCI region.
         */
        if (pci_reserve_start_pfn < end && pci_reserve_end_pfn > start) {
                start = max(pci_reserve_start_pfn, start);
                end = min(pci_reserve_end_pfn, end);
                reserve_bootmem(PFN_PHYS(start), PFN_PHYS(end - start),
                                BOOTMEM_EXCLUSIVE);
        }
#endif
}

static void __init setup_bootmem_allocator(void)
{
        int i;
        for (i = 0; i < MAX_NUMNODES; ++i)
                setup_bootmem_allocator_node(i);

        /* Reserve any memory excluded by "memmap" arguments. */
        for (i = 0; i < memmap_nr; ++i) {
                struct memmap_entry *m = &memmap_map[i];
                reserve_bootmem(m->addr, m->size, BOOTMEM_DEFAULT);
        }

#ifdef CONFIG_BLK_DEV_INITRD
        if (initrd_start) {
                /* Make sure the initrd memory region is not modified. */
                if (reserve_bootmem(initrd_start, initrd_end - initrd_start,
                                    BOOTMEM_EXCLUSIVE)) {
                        pr_crit("The initrd memory region has been polluted. Disabling it.\n");
                        initrd_start = 0;
                        initrd_end = 0;
                } else {
                        /*
                         * Translate initrd_start & initrd_end from PA to VA for
                         * future access.
                         */
                        initrd_start += PAGE_OFFSET;
                        initrd_end += PAGE_OFFSET;
                }
        }
#endif

#ifdef CONFIG_KEXEC
        if (crashk_res.start != crashk_res.end)
                reserve_bootmem(crashk_res.start, resource_size(&crashk_res),
                                BOOTMEM_DEFAULT);
#endif
}

void *__init alloc_remap(int nid, unsigned long size)
{
        int pages = node_end_pfn[nid] - node_start_pfn[nid];
        void *map = pfn_to_kaddr(node_memmap_pfn[nid]);
        BUG_ON(size != pages * sizeof(struct page));
        memset(map, 0, size);
        return map;
}

static int __init percpu_size(void)
{
        int size = __per_cpu_end - __per_cpu_start;
        size += PERCPU_MODULE_RESERVE;
        size += PERCPU_DYNAMIC_EARLY_SIZE;
        if (size < PCPU_MIN_UNIT_SIZE)
                size = PCPU_MIN_UNIT_SIZE;
        size = roundup(size, PAGE_SIZE);

        /* In several places we assume the per-cpu data fits on a huge page. */
        BUG_ON(kdata_huge && size > HPAGE_SIZE);
        return size;
}

static void __init zone_sizes_init(void)
{
        unsigned long zones_size[MAX_NR_ZONES] = { 0 };
        int size = percpu_size();
        int num_cpus = smp_height * smp_width;
        const unsigned long dma_end = (1UL << (32 - PAGE_SHIFT));

        int i;

        for (i = 0; i < num_cpus; ++i)
                node_percpu[cpu_to_node(i)] += size;

        for_each_online_node(i) {
                unsigned long start = node_start_pfn[i];
                unsigned long end = node_end_pfn[i];
#ifdef CONFIG_HIGHMEM
                unsigned long lowmem_end = node_lowmem_end_pfn[i];
#else
                unsigned long lowmem_end = end;
#endif
                int memmap_size = (end - start) * sizeof(struct page);
                node_free_pfn[i] = start;

                /*
                 * Set aside pages for per-cpu data and the mem_map array.
                 *
                 * Since the per-cpu data requires special homecaching,
                 * if we are in kdata_huge mode, we put it at the end of
                 * the lowmem region.  If we're not in kdata_huge mode,
                 * we take the per-cpu pages from the bottom of the
                 * controller, since that avoids fragmenting a huge page
                 * that users might want.  We always take the memmap
                 * from the bottom of the controller, since with
                 * kdata_huge that lets it be under a huge TLB entry.
                 *
                 * If the user has requested isolnodes for a controller,
                 * though, there'll be no lowmem, so we just alloc_bootmem
                 * the memmap.  There will be no percpu memory either.
                 */
                if (i != 0 && node_isset(i, isolnodes)) {
                        node_memmap_pfn[i] =
                                alloc_bootmem_pfn(0, memmap_size, 0);
                        BUG_ON(node_percpu[i] != 0);
                } else if (node_has_bootmem(start)) {
                        unsigned long goal = 0;
                        node_memmap_pfn[i] =
                                alloc_bootmem_pfn(i, memmap_size, 0);
                        if (kdata_huge)
                                goal = PFN_PHYS(lowmem_end) - node_percpu[i];
                        if (node_percpu[i])
                                node_percpu_pfn[i] =
                                        alloc_bootmem_pfn(i, node_percpu[i],
                                                          goal);
                } else {
                        /* In non-bootmem zones, just reserve some pages. */
                        node_memmap_pfn[i] = node_free_pfn[i];
                        node_free_pfn[i] += PFN_UP(memmap_size);
                        if (!kdata_huge) {
                                node_percpu_pfn[i] = node_free_pfn[i];
                                node_free_pfn[i] += PFN_UP(node_percpu[i]);
                        } else {
                                node_percpu_pfn[i] =
                                        lowmem_end - PFN_UP(node_percpu[i]);
                        }
                }

#ifdef CONFIG_HIGHMEM
                if (start > lowmem_end) {
                        zones_size[ZONE_NORMAL] = 0;
                        zones_size[ZONE_HIGHMEM] = end - start;
                } else {
                        zones_size[ZONE_NORMAL] = lowmem_end - start;
                        zones_size[ZONE_HIGHMEM] = end - lowmem_end;
                }
#else
                zones_size[ZONE_NORMAL] = end - start;
#endif

                if (start < dma_end) {
                        zones_size[ZONE_DMA] = min(zones_size[ZONE_NORMAL],
                                                   dma_end - start);
                        zones_size[ZONE_NORMAL] -= zones_size[ZONE_DMA];
                } else {
                        zones_size[ZONE_DMA] = 0;
                }

                /* Take zone metadata from controller 0 if we're isolnode. */
                if (node_isset(i, isolnodes))
                        NODE_DATA(i)->bdata = &bootmem_node_data[0];

                free_area_init_node(i, zones_size, start, NULL);
                printk(KERN_DEBUG "  Normal zone: %ld per-cpu pages\n",
                       PFN_UP(node_percpu[i]));

                /* Track the type of memory on each node */
                if (zones_size[ZONE_NORMAL] || zones_size[ZONE_DMA])
                        node_set_state(i, N_NORMAL_MEMORY);
#ifdef CONFIG_HIGHMEM
                if (end != start)
                        node_set_state(i, N_HIGH_MEMORY);
#endif

                node_set_online(i);
        }
}

#ifdef CONFIG_NUMA

/* which logical CPUs are on which nodes */
struct cpumask node_2_cpu_mask[MAX_NUMNODES] __ro_after_init;
EXPORT_SYMBOL(node_2_cpu_mask);

/* which node each logical CPU is on */
char cpu_2_node[NR_CPUS] __ro_after_init __attribute__((aligned(L2_CACHE_BYTES)));
EXPORT_SYMBOL(cpu_2_node);

/* Return cpu_to_node() except for cpus not yet assigned, which return -1 */
static int __init cpu_to_bound_node(int cpu, struct cpumask* unbound_cpus)
{
        if (!cpu_possible(cpu) || cpumask_test_cpu(cpu, unbound_cpus))
                return -1;
        else
                return cpu_to_node(cpu);
}

/* Return number of immediately-adjacent tiles sharing the same NUMA node. */
static int __init node_neighbors(int node, int cpu,
                                 struct cpumask *unbound_cpus)
{
        int neighbors = 0;
        int w = smp_width;
        int h = smp_height;
        int x = cpu % w;
        int y = cpu / w;
        if (x > 0 && cpu_to_bound_node(cpu-1, unbound_cpus) == node)
                ++neighbors;
        if (x < w-1 && cpu_to_bound_node(cpu+1, unbound_cpus) == node)
                ++neighbors;
        if (y > 0 && cpu_to_bound_node(cpu-w, unbound_cpus) == node)
                ++neighbors;
        if (y < h-1 && cpu_to_bound_node(cpu+w, unbound_cpus) == node)
                ++neighbors;
        return neighbors;
}

static void __init setup_numa_mapping(void)
{
        u8 distance[MAX_NUMNODES][NR_CPUS];
        HV_Coord coord;
        int cpu, node, cpus, i, x, y;
        int num_nodes = num_online_nodes();
        struct cpumask unbound_cpus;
        nodemask_t default_nodes;

        cpumask_clear(&unbound_cpus);

        /* Get set of nodes we will use for defaults */
        nodes_andnot(default_nodes, node_online_map, isolnodes);
        if (nodes_empty(default_nodes)) {
                BUG_ON(!node_isset(0, node_online_map));
                pr_err("Forcing NUMA node zero available as a default node\n");
                node_set(0, default_nodes);
        }

        /* Populate the distance[] array */
        memset(distance, -1, sizeof(distance));
        cpu = 0;
        for (coord.y = 0; coord.y < smp_height; ++coord.y) {
                for (coord.x = 0; coord.x < smp_width;
                     ++coord.x, ++cpu) {
                        BUG_ON(cpu >= nr_cpu_ids);
                        if (!cpu_possible(cpu)) {
                                cpu_2_node[cpu] = -1;
                                continue;
                        }
                        for_each_node_mask(node, default_nodes) {
                                HV_MemoryControllerInfo info =
                                        hv_inquire_memory_controller(
                                                coord, node_controller[node]);
                                distance[node][cpu] =
                                        ABS(info.coord.x) + ABS(info.coord.y);
                        }
                        cpumask_set_cpu(cpu, &unbound_cpus);
                }
        }
        cpus = cpu;

        /*
         * Round-robin through the NUMA nodes until all the cpus are
         * assigned.  We could be more clever here (e.g. create four
         * sorted linked lists on the same set of cpu nodes, and pull
         * off them in round-robin sequence, removing from all four
         * lists each time) but given the relatively small numbers
         * involved, O(n^2) seem OK for a one-time cost.
         */
        node = first_node(default_nodes);
        while (!cpumask_empty(&unbound_cpus)) {
                int best_cpu = -1;
                int best_distance = INT_MAX;
                for (cpu = 0; cpu < cpus; ++cpu) {
                        if (cpumask_test_cpu(cpu, &unbound_cpus)) {
                                /*
                                 * Compute metric, which is how much
                                 * closer the cpu is to this memory
                                 * controller than the others, shifted
                                 * up, and then the number of
                                 * neighbors already in the node as an
                                 * epsilon adjustment to try to keep
                                 * the nodes compact.
                                 */
                                int d = distance[node][cpu] * num_nodes;
                                for_each_node_mask(i, default_nodes) {
                                        if (i != node)
                                                d -= distance[i][cpu];
                                }
                                d *= 8;  /* allow space for epsilon */
                                d -= node_neighbors(node, cpu, &unbound_cpus);
                                if (d < best_distance) {
                                        best_cpu = cpu;
                                        best_distance = d;
                                }
                        }
                }
                BUG_ON(best_cpu < 0);
                cpumask_set_cpu(best_cpu, &node_2_cpu_mask[node]);
                cpu_2_node[best_cpu] = node;
                cpumask_clear_cpu(best_cpu, &unbound_cpus);
                node = next_node_in(node, default_nodes);
        }

        /* Print out node assignments and set defaults for disabled cpus */
        cpu = 0;
        for (y = 0; y < smp_height; ++y) {
                printk(KERN_DEBUG "NUMA cpu-to-node row %d:", y);
                for (x = 0; x < smp_width; ++x, ++cpu) {
                        if (cpu_to_node(cpu) < 0) {
                                pr_cont(" -");
                                cpu_2_node[cpu] = first_node(default_nodes);
                        } else {
                                pr_cont(" %d", cpu_to_node(cpu));
                        }
                }
                pr_cont("\n");
        }
}

static struct cpu cpu_devices[NR_CPUS];

static int __init topology_init(void)
{
        int i;

        for_each_online_node(i)
                register_one_node(i);

        for (i = 0; i < smp_height * smp_width; ++i)
                register_cpu(&cpu_devices[i], i);

        return 0;
}

subsys_initcall(topology_init);

#else /* !CONFIG_NUMA */

#define setup_numa_mapping() do { } while (0)

#endif /* CONFIG_NUMA */

/*
 * Initialize hugepage support on this cpu.  We do this on all cores
 * early in boot: before argument parsing for the boot cpu, and after
 * argument parsing but before the init functions run on the secondaries.
 * So the values we set up here in the hypervisor may be overridden on
 * the boot cpu as arguments are parsed.
 */
static void init_super_pages(void)
{
#ifdef CONFIG_HUGETLB_SUPER_PAGES
        int i;
        for (i = 0; i < HUGE_SHIFT_ENTRIES; ++i)
                hv_set_pte_super_shift(i, huge_shift[i]);
#endif
}

/**
 * setup_cpu() - Do all necessary per-cpu, tile-specific initialization.
 * @boot: Is this the boot cpu?
 *
 * Called from setup_arch() on the boot cpu, or online_secondary().
 */
void setup_cpu(int boot)
{
        /* The boot cpu sets up its permanent mappings much earlier. */
        if (!boot)
                store_permanent_mappings();

        /* Allow asynchronous TLB interrupts. */
#if CHIP_HAS_TILE_DMA()
        arch_local_irq_unmask(INT_DMATLB_MISS);
        arch_local_irq_unmask(INT_DMATLB_ACCESS);
#endif
#ifdef __tilegx__
        arch_local_irq_unmask(INT_SINGLE_STEP_K);
#endif

        /*
         * Allow user access to many generic SPRs, like the cycle
         * counter, PASS/FAIL/DONE, INTERRUPT_CRITICAL_SECTION, etc.
         */
        __insn_mtspr(SPR_MPL_WORLD_ACCESS_SET_0, 1);

#if CHIP_HAS_SN()
        /* Static network is not restricted. */
        __insn_mtspr(SPR_MPL_SN_ACCESS_SET_0, 1);
#endif

        /*
         * Set the MPL for interrupt control 0 & 1 to the corresponding
         * values.  This includes access to the SYSTEM_SAVE and EX_CONTEXT
         * SPRs, as well as the interrupt mask.
         */
        __insn_mtspr(SPR_MPL_INTCTRL_0_SET_0, 1);
        __insn_mtspr(SPR_MPL_INTCTRL_1_SET_1, 1);

        /* Initialize IRQ support for this cpu. */
        setup_irq_regs();

#ifdef CONFIG_HARDWALL
        /* Reset the network state on this cpu. */
        reset_network_state();
#endif

        init_super_pages();
}

#ifdef CONFIG_BLK_DEV_INITRD

static int __initdata set_initramfs_file;
static char __initdata initramfs_file[128] = "initramfs";

static int __init setup_initramfs_file(char *str)
{
        if (str == NULL)
                return -EINVAL;
        strncpy(initramfs_file, str, sizeof(initramfs_file) - 1);
        set_initramfs_file = 1;

        return 0;
}
early_param("initramfs_file", setup_initramfs_file);

/*
 * We look for a file called "initramfs" in the hvfs.  If there is one, we
 * allocate some memory for it and it will be unpacked to the initramfs.
 * If it's compressed, the initd code will uncompress it first.
 */
static void __init load_hv_initrd(void)
{
        HV_FS_StatInfo stat;
        int fd, rc;
        void *initrd;

        /* If initrd has already been set, skip initramfs file in hvfs. */
        if (initrd_start)
                return;

        fd = hv_fs_findfile((HV_VirtAddr) initramfs_file);
        if (fd == HV_ENOENT) {
                if (set_initramfs_file) {
                        pr_warn("No such hvfs initramfs file '%s'\n",
                                initramfs_file);
                        return;
                } else {
                        /* Try old backwards-compatible name. */
                        fd = hv_fs_findfile((HV_VirtAddr)"initramfs.cpio.gz");
                        if (fd == HV_ENOENT)
                                return;
                }
        }
        BUG_ON(fd < 0);
        stat = hv_fs_fstat(fd);
        BUG_ON(stat.size < 0);
        if (stat.flags & HV_FS_ISDIR) {
                pr_warn("Ignoring hvfs file '%s': it's a directory\n",
                        initramfs_file);
                return;
        }
        initrd = alloc_bootmem_pages(stat.size);
        rc = hv_fs_pread(fd, (HV_VirtAddr) initrd, stat.size, 0);
        if (rc != stat.size) {
                pr_err("Error reading %d bytes from hvfs file '%s': %d\n",
                       stat.size, initramfs_file, rc);
                free_initrd_mem((unsigned long) initrd, stat.size);
                return;
        }
        initrd_start = (unsigned long) initrd;
        initrd_end = initrd_start + stat.size;
}

void __init free_initrd_mem(unsigned long begin, unsigned long end)
{
        free_bootmem_late(__pa(begin), end - begin);
}

static int __init setup_initrd(char *str)
{
        char *endp;
        unsigned long initrd_size;

        initrd_size = str ? simple_strtoul(str, &endp, 0) : 0;
        if (initrd_size == 0 || *endp != '@')
                return -EINVAL;

        initrd_start = simple_strtoul(endp+1, &endp, 0);
        if (initrd_start == 0)
                return -EINVAL;

        initrd_end = initrd_start + initrd_size;

        return 0;
}
early_param("initrd", setup_initrd);

#else
static inline void load_hv_initrd(void) {}
#endif /* CONFIG_BLK_DEV_INITRD */

static void __init validate_hv(void)
{
        /*
         * It may already be too late, but let's check our built-in
         * configuration against what the hypervisor is providing.
         */
        unsigned long glue_size = hv_sysconf(HV_SYSCONF_GLUE_SIZE);
        int hv_page_size = hv_sysconf(HV_SYSCONF_PAGE_SIZE_SMALL);
        int hv_hpage_size = hv_sysconf(HV_SYSCONF_PAGE_SIZE_LARGE);
        HV_ASIDRange asid_range;

#ifndef CONFIG_SMP
        HV_Topology topology = hv_inquire_topology();
        BUG_ON(topology.coord.x != 0 || topology.coord.y != 0);
        if (topology.width != 1 || topology.height != 1) {
                pr_warn("Warning: booting UP kernel on %dx%d grid; will ignore all but first tile\n",
                        topology.width, topology.height);
        }
#endif

        if (PAGE_OFFSET + HV_GLUE_START_CPA + glue_size > (unsigned long)_text)
                early_panic("Hypervisor glue size %ld is too big!\n",
                            glue_size);
        if (hv_page_size != PAGE_SIZE)
                early_panic("Hypervisor page size %#x != our %#lx\n",
                            hv_page_size, PAGE_SIZE);
        if (hv_hpage_size != HPAGE_SIZE)
                early_panic("Hypervisor huge page size %#x != our %#lx\n",
                            hv_hpage_size, HPAGE_SIZE);

#ifdef CONFIG_SMP
        /*
         * Some hypervisor APIs take a pointer to a bitmap array
         * whose size is at least the number of cpus on the chip.
         * We use a struct cpumask for this, so it must be big enough.
         */
        if ((smp_height * smp_width) > nr_cpu_ids)
                early_panic("Hypervisor %d x %d grid too big for Linux NR_CPUS %u\n",
                            smp_height, smp_width, nr_cpu_ids);
#endif

        /*
         * Check that we're using allowed ASIDs, and initialize the
         * various asid variables to their appropriate initial states.
         */
        asid_range = hv_inquire_asid(0);
        min_asid = asid_range.start;
        __this_cpu_write(current_asid, min_asid);
        max_asid = asid_range.start + asid_range.size - 1;

        if (hv_confstr(HV_CONFSTR_CHIP_MODEL, (HV_VirtAddr)chip_model,
                       sizeof(chip_model)) < 0) {
                pr_err("Warning: HV_CONFSTR_CHIP_MODEL not available\n");
                strlcpy(chip_model, "unknown", sizeof(chip_model));
        }
}

static void __init validate_va(void)
{
#ifndef __tilegx__   /* FIXME: GX: probably some validation relevant here */
        /*
         * Similarly, make sure we're only using allowed VAs.
         * We assume we can contiguously use MEM_USER_INTRPT .. MEM_HV_START,
         * and 0 .. KERNEL_HIGH_VADDR.
         * In addition, make sure we CAN'T use the end of memory, since
         * we use the last chunk of each pgd for the pgd_list.
         */
        int i, user_kernel_ok = 0;
        unsigned long max_va = 0;
        unsigned long list_va =
                ((PGD_LIST_OFFSET / sizeof(pgd_t)) << PGDIR_SHIFT);

        for (i = 0; ; ++i) {
                HV_VirtAddrRange range = hv_inquire_virtual(i);
                if (range.size == 0)
                        break;
                if (range.start <= MEM_USER_INTRPT &&
                    range.start + range.size >= MEM_HV_START)
                        user_kernel_ok = 1;
                if (range.start == 0)
                        max_va = range.size;
                BUG_ON(range.start + range.size > list_va);
        }
        if (!user_kernel_ok)
                early_panic("Hypervisor not configured for user/kernel VAs\n");
        if (max_va == 0)
                early_panic("Hypervisor not configured for low VAs\n");
        if (max_va < KERNEL_HIGH_VADDR)
                early_panic("Hypervisor max VA %#lx smaller than %#lx\n",
                            max_va, KERNEL_HIGH_VADDR);

        /* Kernel PCs must have their high bit set; see intvec.S. */
        if ((long)VMALLOC_START >= 0)
                early_panic("Linux VMALLOC region below the 2GB line (%#lx)!\n"
                            "Reconfigure the kernel with smaller VMALLOC_RESERVE\n",
                            VMALLOC_START);
#endif
}

/*
 * cpu_lotar_map lists all the cpus that are valid for the supervisor
 * to cache data on at a page level, i.e. what cpus can be placed in
 * the LOTAR field of a PTE.  It is equivalent to the set of possible
 * cpus plus any other cpus that are willing to share their cache.
 * It is set by hv_inquire_tiles(HV_INQ_TILES_LOTAR).
 */
struct cpumask __ro_after_init cpu_lotar_map;
EXPORT_SYMBOL(cpu_lotar_map);

/*
 * hash_for_home_map lists all the tiles that hash-for-home data
 * will be cached on.  Note that this may includes tiles that are not
 * valid for this supervisor to use otherwise (e.g. if a hypervisor
 * device is being shared between multiple supervisors).
 * It is set by hv_inquire_tiles(HV_INQ_TILES_HFH_CACHE).
 */
struct cpumask hash_for_home_map;
EXPORT_SYMBOL(hash_for_home_map);

/*
 * cpu_cacheable_map lists all the cpus whose caches the hypervisor can
 * flush on our behalf.  It is set to cpu_possible_mask OR'ed with
 * hash_for_home_map, and it is what should be passed to
 * hv_flush_remote() to flush all caches.  Note that if there are
 * dedicated hypervisor driver tiles that have authorized use of their
 * cache, those tiles will only appear in cpu_lotar_map, NOT in
 * cpu_cacheable_map, as they are a special case.
 */
struct cpumask __ro_after_init cpu_cacheable_map;
EXPORT_SYMBOL(cpu_cacheable_map);

static __initdata struct cpumask disabled_map;

static int __init disabled_cpus(char *str)
{
        int boot_cpu = smp_processor_id();

        if (str == NULL || cpulist_parse_crop(str, &disabled_map) != 0)
                return -EINVAL;
        if (cpumask_test_cpu(boot_cpu, &disabled_map)) {
                pr_err("disabled_cpus: can't disable boot cpu %d\n", boot_cpu);
                cpumask_clear_cpu(boot_cpu, &disabled_map);
        }
        return 0;
}

early_param("disabled_cpus", disabled_cpus);

void __init print_disabled_cpus(void)
{
        if (!cpumask_empty(&disabled_map))
                pr_info("CPUs not available for Linux: %*pbl\n",
                        cpumask_pr_args(&disabled_map));
}

static void __init setup_cpu_maps(void)
{
        struct cpumask hv_disabled_map, cpu_possible_init;
        int boot_cpu = smp_processor_id();
        int cpus, i, rc;

        /* Learn which cpus are allowed by the hypervisor. */
        rc = hv_inquire_tiles(HV_INQ_TILES_AVAIL,
                              (HV_VirtAddr) cpumask_bits(&cpu_possible_init),
                              sizeof(cpu_cacheable_map));
        if (rc < 0)
                early_panic("hv_inquire_tiles(AVAIL) failed: rc %d\n", rc);
        if (!cpumask_test_cpu(boot_cpu, &cpu_possible_init))
                early_panic("Boot CPU %d disabled by hypervisor!\n", boot_cpu);

        /* Compute the cpus disabled by the hvconfig file. */
        cpumask_complement(&hv_disabled_map, &cpu_possible_init);

        /* Include them with the cpus disabled by "disabled_cpus". */
        cpumask_or(&disabled_map, &disabled_map, &hv_disabled_map);

        /*
         * Disable every cpu after "setup_max_cpus".  But don't mark
         * as disabled the cpus that are outside of our initial rectangle,
         * since that turns out to be confusing.
         */
        cpus = 1;                          /* this cpu */
        cpumask_set_cpu(boot_cpu, &disabled_map);   /* ignore this cpu */
        for (i = 0; cpus < setup_max_cpus; ++i)
                if (!cpumask_test_cpu(i, &disabled_map))
                        ++cpus;
        for (; i < smp_height * smp_width; ++i)
                cpumask_set_cpu(i, &disabled_map);
        cpumask_clear_cpu(boot_cpu, &disabled_map); /* reset this cpu */
        for (i = smp_height * smp_width; i < NR_CPUS; ++i)
                cpumask_clear_cpu(i, &disabled_map);

        /*
         * Setup cpu_possible map as every cpu allocated to us, minus
         * the results of any "disabled_cpus" settings.
         */
        cpumask_andnot(&cpu_possible_init, &cpu_possible_init, &disabled_map);
        init_cpu_possible(&cpu_possible_init);

        /* Learn which cpus are valid for LOTAR caching. */
        rc = hv_inquire_tiles(HV_INQ_TILES_LOTAR,
                              (HV_VirtAddr) cpumask_bits(&cpu_lotar_map),
                              sizeof(cpu_lotar_map));
        if (rc < 0) {
                pr_err("warning: no HV_INQ_TILES_LOTAR; using AVAIL\n");
                cpu_lotar_map = *cpu_possible_mask;
        }

        /* Retrieve set of CPUs used for hash-for-home caching */
        rc = hv_inquire_tiles(HV_INQ_TILES_HFH_CACHE,
                              (HV_VirtAddr) hash_for_home_map.bits,
                              sizeof(hash_for_home_map));
        if (rc < 0)
                early_panic("hv_inquire_tiles(HFH_CACHE) failed: rc %d\n", rc);
        cpumask_or(&cpu_cacheable_map, cpu_possible_mask, &hash_for_home_map);
}


static int __init dataplane(char *str)
{
        pr_warn("WARNING: dataplane support disabled in this kernel\n");
        return 0;
}

early_param("dataplane", dataplane);

#ifdef CONFIG_NO_HZ_FULL
/* Warn if hypervisor shared cpus are marked as nohz_full. */
static int __init check_nohz_full_cpus(void)
{
        struct cpumask shared;
        int cpu;

        if (hv_inquire_tiles(HV_INQ_TILES_SHARED,
                             (HV_VirtAddr) shared.bits, sizeof(shared)) < 0) {
                pr_warn("WARNING: No support for inquiring hv shared tiles\n");
                return 0;
        }
        for_each_cpu(cpu, &shared) {
                if (tick_nohz_full_cpu(cpu))
                        pr_warn("WARNING: nohz_full cpu %d receives hypervisor interrupts!\n",
                               cpu);
        }
        return 0;
}
arch_initcall(check_nohz_full_cpus);
#endif

#ifdef CONFIG_CMDLINE_BOOL
static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
#endif

void __init setup_arch(char **cmdline_p)
{
        int len;

#if defined(CONFIG_CMDLINE_BOOL) && defined(CONFIG_CMDLINE_OVERRIDE)
        len = hv_get_command_line((HV_VirtAddr) boot_command_line,
                                  COMMAND_LINE_SIZE);
        if (boot_command_line[0])
                pr_warn("WARNING: ignoring dynamic command line \"%s\"\n",
                        boot_command_line);
        strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
#else
        char *hv_cmdline;
#if defined(CONFIG_CMDLINE_BOOL)
        if (builtin_cmdline[0]) {
                int builtin_len = strlcpy(boot_command_line, builtin_cmdline,
                                          COMMAND_LINE_SIZE);
                if (builtin_len < COMMAND_LINE_SIZE-1)
                        boot_command_line[builtin_len++] = ' ';
                hv_cmdline = &boot_command_line[builtin_len];
                len = COMMAND_LINE_SIZE - builtin_len;
        } else
#endif
        {
                hv_cmdline = boot_command_line;
                len = COMMAND_LINE_SIZE;
        }
        len = hv_get_command_line((HV_VirtAddr) hv_cmdline, len);
        if (len < 0 || len > COMMAND_LINE_SIZE)
                early_panic("hv_get_command_line failed: %d\n", len);
#endif

        *cmdline_p = boot_command_line;

        /* Set disabled_map and setup_max_cpus very early */
        parse_early_param();

        /* Make sure the kernel is compatible with the hypervisor. */
        validate_hv();
        validate_va();

        setup_cpu_maps();


#if defined(CONFIG_PCI) && !defined(__tilegx__)
        /*
         * Initialize the PCI structures.  This is done before memory
         * setup so that we know whether or not a pci_reserve region
         * is necessary.
         */
        if (tile_pci_init() == 0)
                pci_reserve_mb = 0;

        /* PCI systems reserve a region just below 4GB for mapping iomem. */
        pci_reserve_end_pfn  = (1 << (32 - PAGE_SHIFT));
        pci_reserve_start_pfn = pci_reserve_end_pfn -
                (pci_reserve_mb << (20 - PAGE_SHIFT));
#endif

        init_mm.start_code = (unsigned long) _text;
        init_mm.end_code = (unsigned long) _etext;
        init_mm.end_data = (unsigned long) _edata;
        init_mm.brk = (unsigned long) _end;

        setup_memory();
        store_permanent_mappings();
        setup_bootmem_allocator();

        /*
         * NOTE: before this point _nobody_ is allowed to allocate
         * any memory using the bootmem allocator.
         */

#ifdef CONFIG_SWIOTLB
        swiotlb_init(0);
#endif

        paging_init();
        setup_numa_mapping();
        zone_sizes_init();
        set_page_homes();
        setup_cpu(1);
        setup_clock();
        load_hv_initrd();
}


/*
 * Set up per-cpu memory.
 */

unsigned long __per_cpu_offset[NR_CPUS] __ro_after_init;
EXPORT_SYMBOL(__per_cpu_offset);

static size_t __initdata pfn_offset[MAX_NUMNODES] = { 0 };
static unsigned long __initdata percpu_pfn[NR_CPUS] = { 0 };

/*
 * As the percpu code allocates pages, we return the pages from the
 * end of the node for the specified cpu.
 */
static void *__init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
{
        int nid = cpu_to_node(cpu);
        unsigned long pfn = node_percpu_pfn[nid] + pfn_offset[nid];

        BUG_ON(size % PAGE_SIZE != 0);
        pfn_offset[nid] += size / PAGE_SIZE;
        BUG_ON(node_percpu[nid] < size);
        node_percpu[nid] -= size;
        if (percpu_pfn[cpu] == 0)
                percpu_pfn[cpu] = pfn;
        return pfn_to_kaddr(pfn);
}

/*
 * Pages reserved for percpu memory are not freeable, and in any case we are
 * on a short path to panic() in setup_per_cpu_area() at this point anyway.
 */
static void __init pcpu_fc_free(void *ptr, size_t size)
{
}

/*
 * Set up vmalloc page tables using bootmem for the percpu code.
 */
static void __init pcpu_fc_populate_pte(unsigned long addr)
{
        pgd_t *pgd;
        pud_t *pud;
        pmd_t *pmd;
        pte_t *pte;

        BUG_ON(pgd_addr_invalid(addr));
        if (addr < VMALLOC_START || addr >= VMALLOC_END)
                panic("PCPU addr %#lx outside vmalloc range %#lx..%#lx; try increasing CONFIG_VMALLOC_RESERVE\n",
                      addr, VMALLOC_START, VMALLOC_END);

        pgd = swapper_pg_dir + pgd_index(addr);
        pud = pud_offset(pgd, addr);
        BUG_ON(!pud_present(*pud));
        pmd = pmd_offset(pud, addr);
        if (pmd_present(*pmd)) {
                BUG_ON(pmd_huge_page(*pmd));
        } else {
                pte = __alloc_bootmem(L2_KERNEL_PGTABLE_SIZE,
                                      HV_PAGE_TABLE_ALIGN, 0);
                pmd_populate_kernel(&init_mm, pmd, pte);
        }
}

void __init setup_per_cpu_areas(void)
{
        struct page *pg;
        unsigned long delta, pfn, lowmem_va;
        unsigned long size = percpu_size();
        char *ptr;
        int rc, cpu, i;

        rc = pcpu_page_first_chunk(PERCPU_MODULE_RESERVE, pcpu_fc_alloc,
                                   pcpu_fc_free, pcpu_fc_populate_pte);
        if (rc < 0)
                panic("Cannot initialize percpu area (err=%d)", rc);

        delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
        for_each_possible_cpu(cpu) {
                __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];

                /* finv the copy out of cache so we can change homecache */
                ptr = pcpu_base_addr + pcpu_unit_offsets[cpu];
                __finv_buffer(ptr, size);
                pfn = percpu_pfn[cpu];

                /* Rewrite the page tables to cache on that cpu */
                pg = pfn_to_page(pfn);
                for (i = 0; i < size; i += PAGE_SIZE, ++pfn, ++pg) {

                        /* Update the vmalloc mapping and page home. */
                        unsigned long addr = (unsigned long)ptr + i;
                        pte_t *ptep = virt_to_kpte(addr);
                        pte_t pte = *ptep;
                        BUG_ON(pfn != pte_pfn(pte));
                        pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_TILE_L3);
                        pte = set_remote_cache_cpu(pte, cpu);
                        set_pte_at(&init_mm, addr, ptep, pte);

                        /* Update the lowmem mapping for consistency. */
                        lowmem_va = (unsigned long)pfn_to_kaddr(pfn);
                        ptep = virt_to_kpte(lowmem_va);
                        if (pte_huge(*ptep)) {
                                printk(KERN_DEBUG "early shatter of huge page at %#lx\n",
                                       lowmem_va);
                                shatter_pmd((pmd_t *)ptep);
                                ptep = virt_to_kpte(lowmem_va);
                                BUG_ON(pte_huge(*ptep));
                        }
                        BUG_ON(pfn != pte_pfn(*ptep));
                        set_pte_at(&init_mm, lowmem_va, ptep, pte);
                }
        }

        /* Set our thread pointer appropriately. */
        set_my_cpu_offset(__per_cpu_offset[smp_processor_id()]);

        /* Make sure the finv's have completed. */
        mb_incoherent();

        /* Flush the TLB so we reference it properly from here on out. */
        local_flush_tlb_all();
}

static struct resource data_resource = {
        .name   = "Kernel data",
        .start  = 0,
        .end    = 0,
        .flags  = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};

static struct resource code_resource = {
        .name   = "Kernel code",
        .start  = 0,
        .end    = 0,
        .flags  = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
};

/*
 * On Pro, we reserve all resources above 4GB so that PCI won't try to put
 * mappings above 4GB.
 */
#if defined(CONFIG_PCI) && !defined(__tilegx__)
static struct resource* __init
insert_non_bus_resource(void)
{
        struct resource *res =
                kzalloc(sizeof(struct resource), GFP_ATOMIC);
        if (!res)
                return NULL;
        res->name = "Non-Bus Physical Address Space";
        res->start = (1ULL << 32);
        res->end = -1LL;
        res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
        if (insert_resource(&iomem_resource, res)) {
                kfree(res);
                return NULL;
        }
        return res;
}
#endif

static struct resource* __init
insert_ram_resource(u64 start_pfn, u64 end_pfn, bool reserved)
{
        struct resource *res =
                kzalloc(sizeof(struct resource), GFP_ATOMIC);
        if (!res)
                return NULL;
        res->start = start_pfn << PAGE_SHIFT;
        res->end = (end_pfn << PAGE_SHIFT) - 1;
        res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
        if (reserved) {
                res->name = "Reserved";
        } else {
                res->name = "System RAM";
                res->flags |= IORESOURCE_SYSRAM;
        }
        if (insert_resource(&iomem_resource, res)) {
                kfree(res);
                return NULL;
        }
        return res;
}

/*
 * Request address space for all standard resources
 *
 * If the system includes PCI root complex drivers, we need to create
 * a window just below 4GB where PCI BARs can be mapped.
 */
static int __init request_standard_resources(void)
{
        int i;
        enum { CODE_DELTA = MEM_SV_START - PAGE_OFFSET };

#if defined(CONFIG_PCI) && !defined(__tilegx__)
        insert_non_bus_resource();
#endif

        for_each_online_node(i) {
                u64 start_pfn = node_start_pfn[i];
                u64 end_pfn = node_end_pfn[i];

#if defined(CONFIG_PCI) && !defined(__tilegx__)
                if (start_pfn <= pci_reserve_start_pfn &&
                    end_pfn > pci_reserve_start_pfn) {
                        if (end_pfn > pci_reserve_end_pfn)
                                insert_ram_resource(pci_reserve_end_pfn,
                                                    end_pfn, 0);
                        end_pfn = pci_reserve_start_pfn;
                }
#endif
                insert_ram_resource(start_pfn, end_pfn, 0);
        }

        code_resource.start = __pa(_text - CODE_DELTA);
        code_resource.end = __pa(_etext - CODE_DELTA)-1;
        data_resource.start = __pa(_sdata);
        data_resource.end = __pa(_end)-1;

        insert_resource(&iomem_resource, &code_resource);
        insert_resource(&iomem_resource, &data_resource);

        /* Mark any "memmap" regions busy for the resource manager. */
        for (i = 0; i < memmap_nr; ++i) {
                struct memmap_entry *m = &memmap_map[i];
                insert_ram_resource(PFN_DOWN(m->addr),
                                    PFN_UP(m->addr + m->size - 1), 1);
        }

#ifdef CONFIG_KEXEC
        insert_resource(&iomem_resource, &crashk_res);
#endif

        return 0;
}

subsys_initcall(request_standard_resources);