Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 983 insertions, 0 deletions

diff --git a/kernel/arch/tile/mm/init.c b/kernel/arch/tile/mm/init.c
new file mode 100644
index 000000000..5bd252e3f
--- /dev/null
+++ b/kernel/arch/tile/mm/init.c
@@ -0,0 +1,983 @@
+/*
+ * Copyright (C) 1995  Linus Torvalds
+ * 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/module.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <linux/poison.h>
+#include <linux/bootmem.h>
+#include <linux/slab.h>
+#include <linux/proc_fs.h>
+#include <linux/efi.h>
+#include <linux/memory_hotplug.h>
+#include <linux/uaccess.h>
+#include <asm/mmu_context.h>
+#include <asm/processor.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/dma.h>
+#include <asm/fixmap.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/homecache.h>
+#include <hv/hypervisor.h>
+#include <arch/chip.h>
+
+#include "migrate.h"
+
+#define clear_pgd(pmdptr) (*(pmdptr) = hv_pte(0))
+
+#ifndef __tilegx__
+unsigned long VMALLOC_RESERVE = CONFIG_VMALLOC_RESERVE;
+EXPORT_SYMBOL(VMALLOC_RESERVE);
+#endif
+
+/* Create an L2 page table */
+static pte_t * __init alloc_pte(void)
+{
+	return __alloc_bootmem(L2_KERNEL_PGTABLE_SIZE, HV_PAGE_TABLE_ALIGN, 0);
+}
+
+/*
+ * L2 page tables per controller.  We allocate these all at once from
+ * the bootmem allocator and store them here.  This saves on kernel L2
+ * page table memory, compared to allocating a full 64K page per L2
+ * page table, and also means that in cases where we use huge pages,
+ * we are guaranteed to later be able to shatter those huge pages and
+ * switch to using these page tables instead, without requiring
+ * further allocation.  Each l2_ptes[] entry points to the first page
+ * table for the first hugepage-size piece of memory on the
+ * controller; other page tables are just indexed directly, i.e. the
+ * L2 page tables are contiguous in memory for each controller.
+ */
+static pte_t *l2_ptes[MAX_NUMNODES];
+static int num_l2_ptes[MAX_NUMNODES];
+
+static void init_prealloc_ptes(int node, int pages)
+{
+	BUG_ON(pages & (PTRS_PER_PTE - 1));
+	if (pages) {
+		num_l2_ptes[node] = pages;
+		l2_ptes[node] = __alloc_bootmem(pages * sizeof(pte_t),
+						HV_PAGE_TABLE_ALIGN, 0);
+	}
+}
+
+pte_t *get_prealloc_pte(unsigned long pfn)
+{
+	int node = pfn_to_nid(pfn);
+	pfn &= ~(-1UL << (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT));
+	BUG_ON(node >= MAX_NUMNODES);
+	BUG_ON(pfn >= num_l2_ptes[node]);
+	return &l2_ptes[node][pfn];
+}
+
+/*
+ * What caching do we expect pages from the heap to have when
+ * they are allocated during bootup?  (Once we've installed the
+ * "real" swapper_pg_dir.)
+ */
+static int initial_heap_home(void)
+{
+	if (hash_default)
+		return PAGE_HOME_HASH;
+	return smp_processor_id();
+}
+
+/*
+ * Place a pointer to an L2 page table in a middle page
+ * directory entry.
+ */
+static void __init assign_pte(pmd_t *pmd, pte_t *page_table)
+{
+	phys_addr_t pa = __pa(page_table);
+	unsigned long l2_ptfn = pa >> HV_LOG2_PAGE_TABLE_ALIGN;
+	pte_t pteval = hv_pte_set_ptfn(__pgprot(_PAGE_TABLE), l2_ptfn);
+	BUG_ON((pa & (HV_PAGE_TABLE_ALIGN-1)) != 0);
+	pteval = pte_set_home(pteval, initial_heap_home());
+	*(pte_t *)pmd = pteval;
+	if (page_table != (pte_t *)pmd_page_vaddr(*pmd))
+		BUG();
+}
+
+#ifdef __tilegx__
+
+static inline pmd_t *alloc_pmd(void)
+{
+	return __alloc_bootmem(L1_KERNEL_PGTABLE_SIZE, HV_PAGE_TABLE_ALIGN, 0);
+}
+
+static inline void assign_pmd(pud_t *pud, pmd_t *pmd)
+{
+	assign_pte((pmd_t *)pud, (pte_t *)pmd);
+}
+
+#endif /* __tilegx__ */
+
+/* Replace the given pmd with a full PTE table. */
+void __init shatter_pmd(pmd_t *pmd)
+{
+	pte_t *pte = get_prealloc_pte(pte_pfn(*(pte_t *)pmd));
+	assign_pte(pmd, pte);
+}
+
+#ifdef __tilegx__
+static pmd_t *__init get_pmd(pgd_t pgtables[], unsigned long va)
+{
+	pud_t *pud = pud_offset(&pgtables[pgd_index(va)], va);
+	if (pud_none(*pud))
+		assign_pmd(pud, alloc_pmd());
+	return pmd_offset(pud, va);
+}
+#else
+static pmd_t *__init get_pmd(pgd_t pgtables[], unsigned long va)
+{
+	return pmd_offset(pud_offset(&pgtables[pgd_index(va)], va), va);
+}
+#endif
+
+/*
+ * This function initializes a certain range of kernel virtual memory
+ * with new bootmem page tables, everywhere page tables are missing in
+ * the given range.
+ */
+
+/*
+ * NOTE: The pagetables are allocated contiguous on the physical space
+ * so we can cache the place of the first one and move around without
+ * checking the pgd every time.
+ */
+static void __init page_table_range_init(unsigned long start,
+					 unsigned long end, pgd_t *pgd)
+{
+	unsigned long vaddr;
+	start = round_down(start, PMD_SIZE);
+	end = round_up(end, PMD_SIZE);
+	for (vaddr = start; vaddr < end; vaddr += PMD_SIZE) {
+		pmd_t *pmd = get_pmd(pgd, vaddr);
+		if (pmd_none(*pmd))
+			assign_pte(pmd, alloc_pte());
+	}
+}
+
+
+static int __initdata ktext_hash = 1;  /* .text pages */
+static int __initdata kdata_hash = 1;  /* .data and .bss pages */
+int __write_once hash_default = 1;     /* kernel allocator pages */
+EXPORT_SYMBOL(hash_default);
+int __write_once kstack_hash = 1;      /* if no homecaching, use h4h */
+
+/*
+ * CPUs to use to for striping the pages of kernel data.  If hash-for-home
+ * is available, this is only relevant if kcache_hash sets up the
+ * .data and .bss to be page-homed, and we don't want the default mode
+ * of using the full set of kernel cpus for the striping.
+ */
+static __initdata struct cpumask kdata_mask;
+static __initdata int kdata_arg_seen;
+
+int __write_once kdata_huge;       /* if no homecaching, small pages */
+
+
+/* Combine a generic pgprot_t with cache home to get a cache-aware pgprot. */
+static pgprot_t __init construct_pgprot(pgprot_t prot, int home)
+{
+	prot = pte_set_home(prot, home);
+	if (home == PAGE_HOME_IMMUTABLE) {
+		if (ktext_hash)
+			prot = hv_pte_set_mode(prot, HV_PTE_MODE_CACHE_HASH_L3);
+		else
+			prot = hv_pte_set_mode(prot, HV_PTE_MODE_CACHE_NO_L3);
+	}
+	return prot;
+}
+
+/*
+ * For a given kernel data VA, how should it be cached?
+ * We return the complete pgprot_t with caching bits set.
+ */
+static pgprot_t __init init_pgprot(ulong address)
+{
+	int cpu;
+	unsigned long page;
+	enum { CODE_DELTA = MEM_SV_START - PAGE_OFFSET };
+
+	/* For kdata=huge, everything is just hash-for-home. */
+	if (kdata_huge)
+		return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
+
+	/*
+	 * We map the aliased pages of permanent text so we can
+	 * update them if necessary, for ftrace, etc.
+	 */
+	if (address < (ulong) _sinittext - CODE_DELTA)
+		return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
+
+	/* We map read-only data non-coherent for performance. */
+	if ((address >= (ulong) __start_rodata &&
+	     address < (ulong) __end_rodata) ||
+	    address == (ulong) empty_zero_page) {
+		return construct_pgprot(PAGE_KERNEL_RO, PAGE_HOME_IMMUTABLE);
+	}
+
+#ifndef __tilegx__
+	/* Force the atomic_locks[] array page to be hash-for-home. */
+	if (address == (ulong) atomic_locks)
+		return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
+#endif
+
+	/*
+	 * Everything else that isn't data or bss is heap, so mark it
+	 * with the initial heap home (hash-for-home, or this cpu).  This
+	 * includes any addresses after the loaded image and any address before
+	 * __init_end, since we already captured the case of text before
+	 * _sinittext, and __pa(einittext) is approximately __pa(__init_begin).
+	 *
+	 * All the LOWMEM pages that we mark this way will get their
+	 * struct page homecache properly marked later, in set_page_homes().
+	 * The HIGHMEM pages we leave with a default zero for their
+	 * homes, but with a zero free_time we don't have to actually
+	 * do a flush action the first time we use them, either.
+	 */
+	if (address >= (ulong) _end || address < (ulong) __init_end)
+		return construct_pgprot(PAGE_KERNEL, initial_heap_home());
+
+	/* Use hash-for-home if requested for data/bss. */
+	if (kdata_hash)
+		return construct_pgprot(PAGE_KERNEL, PAGE_HOME_HASH);
+
+	/*
+	 * Otherwise we just hand out consecutive cpus.  To avoid
+	 * requiring this function to hold state, we just walk forward from
+	 * __end_rodata by PAGE_SIZE, skipping the readonly and init data, to
+	 * reach the requested address, while walking cpu home around
+	 * kdata_mask. This is typically no more than a dozen or so iterations.
+	 */
+	page = (((ulong)__end_rodata) + PAGE_SIZE - 1) & PAGE_MASK;
+	BUG_ON(address < page || address >= (ulong)_end);
+	cpu = cpumask_first(&kdata_mask);
+	for (; page < address; page += PAGE_SIZE) {
+		if (page >= (ulong)&init_thread_union &&
+		    page < (ulong)&init_thread_union + THREAD_SIZE)
+			continue;
+		if (page == (ulong)empty_zero_page)
+			continue;
+#ifndef __tilegx__
+		if (page == (ulong)atomic_locks)
+			continue;
+#endif
+		cpu = cpumask_next(cpu, &kdata_mask);
+		if (cpu == NR_CPUS)
+			cpu = cpumask_first(&kdata_mask);
+	}
+	return construct_pgprot(PAGE_KERNEL, cpu);
+}
+
+/*
+ * This function sets up how we cache the kernel text.  If we have
+ * hash-for-home support, normally that is used instead (see the
+ * kcache_hash boot flag for more information).  But if we end up
+ * using a page-based caching technique, this option sets up the
+ * details of that.  In addition, the "ktext=nocache" option may
+ * always be used to disable local caching of text pages, if desired.
+ */
+
+static int __initdata ktext_arg_seen;
+static int __initdata ktext_small;
+static int __initdata ktext_local;
+static int __initdata ktext_all;
+static int __initdata ktext_nondataplane;
+static int __initdata ktext_nocache;
+static struct cpumask __initdata ktext_mask;
+
+static int __init setup_ktext(char *str)
+{
+	if (str == NULL)
+		return -EINVAL;
+
+	/* If you have a leading "nocache", turn off ktext caching */
+	if (strncmp(str, "nocache", 7) == 0) {
+		ktext_nocache = 1;
+		pr_info("ktext: disabling local caching of kernel text\n");
+		str += 7;
+		if (*str == ',')
+			++str;
+		if (*str == '\0')
+			return 0;
+	}
+
+	ktext_arg_seen = 1;
+
+	/* Default setting: use a huge page */
+	if (strcmp(str, "huge") == 0)
+		pr_info("ktext: using one huge locally cached page\n");
+
+	/* Pay TLB cost but get no cache benefit: cache small pages locally */
+	else if (strcmp(str, "local") == 0) {
+		ktext_small = 1;
+		ktext_local = 1;
+		pr_info("ktext: using small pages with local caching\n");
+	}
+
+	/* Neighborhood cache ktext pages on all cpus. */
+	else if (strcmp(str, "all") == 0) {
+		ktext_small = 1;
+		ktext_all = 1;
+		pr_info("ktext: using maximal caching neighborhood\n");
+	}
+
+
+	/* Neighborhood ktext pages on specified mask */
+	else if (cpulist_parse(str, &ktext_mask) == 0) {
+		if (cpumask_weight(&ktext_mask) > 1) {
+			ktext_small = 1;
+			pr_info("ktext: using caching neighborhood %*pbl with small pages\n",
+				cpumask_pr_args(&ktext_mask));
+		} else {
+			pr_info("ktext: caching on cpu %*pbl with one huge page\n",
+				cpumask_pr_args(&ktext_mask));
+		}
+	}
+
+	else if (*str)
+		return -EINVAL;
+
+	return 0;
+}
+
+early_param("ktext", setup_ktext);
+
+
+static inline pgprot_t ktext_set_nocache(pgprot_t prot)
+{
+	if (!ktext_nocache)
+		prot = hv_pte_set_nc(prot);
+	else
+		prot = hv_pte_set_no_alloc_l2(prot);
+	return prot;
+}
+
+/* Temporary page table we use for staging. */
+static pgd_t pgtables[PTRS_PER_PGD]
+ __attribute__((aligned(HV_PAGE_TABLE_ALIGN)));
+
+/*
+ * This maps the physical memory to kernel virtual address space, a total
+ * of max_low_pfn pages, by creating page tables starting from address
+ * PAGE_OFFSET.
+ *
+ * This routine transitions us from using a set of compiled-in large
+ * pages to using some more precise caching, including removing access
+ * to code pages mapped at PAGE_OFFSET (executed only at MEM_SV_START)
+ * marking read-only data as locally cacheable, striping the remaining
+ * .data and .bss across all the available tiles, and removing access
+ * to pages above the top of RAM (thus ensuring a page fault from a bad
+ * virtual address rather than a hypervisor shoot down for accessing
+ * memory outside the assigned limits).
+ */
+static void __init kernel_physical_mapping_init(pgd_t *pgd_base)
+{
+	unsigned long long irqmask;
+	unsigned long address, pfn;
+	pmd_t *pmd;
+	pte_t *pte;
+	int pte_ofs;
+	const struct cpumask *my_cpu_mask = cpumask_of(smp_processor_id());
+	struct cpumask kstripe_mask;
+	int rc, i;
+
+	if (ktext_arg_seen && ktext_hash) {
+		pr_warn("warning: \"ktext\" boot argument ignored if \"kcache_hash\" sets up text hash-for-home\n");
+		ktext_small = 0;
+	}
+
+	if (kdata_arg_seen && kdata_hash) {
+		pr_warn("warning: \"kdata\" boot argument ignored if \"kcache_hash\" sets up data hash-for-home\n");
+	}
+
+	if (kdata_huge && !hash_default) {
+		pr_warn("warning: disabling \"kdata=huge\"; requires kcache_hash=all or =allbutstack\n");
+		kdata_huge = 0;
+	}
+
+	/*
+	 * Set up a mask for cpus to use for kernel striping.
+	 * This is normally all cpus, but minus dataplane cpus if any.
+	 * If the dataplane covers the whole chip, we stripe over
+	 * the whole chip too.
+	 */
+	cpumask_copy(&kstripe_mask, cpu_possible_mask);
+	if (!kdata_arg_seen)
+		kdata_mask = kstripe_mask;
+
+	/* Allocate and fill in L2 page tables */
+	for (i = 0; i < MAX_NUMNODES; ++i) {
+#ifdef CONFIG_HIGHMEM
+		unsigned long end_pfn = node_lowmem_end_pfn[i];
+#else
+		unsigned long end_pfn = node_end_pfn[i];
+#endif
+		unsigned long end_huge_pfn = 0;
+
+		/* Pre-shatter the last huge page to allow per-cpu pages. */
+		if (kdata_huge)
+			end_huge_pfn = end_pfn - (HPAGE_SIZE >> PAGE_SHIFT);
+
+		pfn = node_start_pfn[i];
+
+		/* Allocate enough memory to hold L2 page tables for node. */
+		init_prealloc_ptes(i, end_pfn - pfn);
+
+		address = (unsigned long) pfn_to_kaddr(pfn);
+		while (pfn < end_pfn) {
+			BUG_ON(address & (HPAGE_SIZE-1));
+			pmd = get_pmd(pgtables, address);
+			pte = get_prealloc_pte(pfn);
+			if (pfn < end_huge_pfn) {
+				pgprot_t prot = init_pgprot(address);
+				*(pte_t *)pmd = pte_mkhuge(pfn_pte(pfn, prot));
+				for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE;
+				     pfn++, pte_ofs++, address += PAGE_SIZE)
+					pte[pte_ofs] = pfn_pte(pfn, prot);
+			} else {
+				if (kdata_huge)
+					printk(KERN_DEBUG "pre-shattered huge page at %#lx\n",
+					       address);
+				for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE;
+				     pfn++, pte_ofs++, address += PAGE_SIZE) {
+					pgprot_t prot = init_pgprot(address);
+					pte[pte_ofs] = pfn_pte(pfn, prot);
+				}
+				assign_pte(pmd, pte);
+			}
+		}
+	}
+
+	/*
+	 * Set or check ktext_map now that we have cpu_possible_mask
+	 * and kstripe_mask to work with.
+	 */
+	if (ktext_all)
+		cpumask_copy(&ktext_mask, cpu_possible_mask);
+	else if (ktext_nondataplane)
+		ktext_mask = kstripe_mask;
+	else if (!cpumask_empty(&ktext_mask)) {
+		/* Sanity-check any mask that was requested */
+		struct cpumask bad;
+		cpumask_andnot(&bad, &ktext_mask, cpu_possible_mask);
+		cpumask_and(&ktext_mask, &ktext_mask, cpu_possible_mask);
+		if (!cpumask_empty(&bad))
+			pr_info("ktext: not using unavailable cpus %*pbl\n",
+				cpumask_pr_args(&bad));
+		if (cpumask_empty(&ktext_mask)) {
+			pr_warn("ktext: no valid cpus; caching on %d\n",
+				smp_processor_id());
+			cpumask_copy(&ktext_mask,
+				     cpumask_of(smp_processor_id()));
+		}
+	}
+
+	address = MEM_SV_START;
+	pmd = get_pmd(pgtables, address);
+	pfn = 0;  /* code starts at PA 0 */
+	if (ktext_small) {
+		/* Allocate an L2 PTE for the kernel text */
+		int cpu = 0;
+		pgprot_t prot = construct_pgprot(PAGE_KERNEL_EXEC,
+						 PAGE_HOME_IMMUTABLE);
+
+		if (ktext_local) {
+			if (ktext_nocache)
+				prot = hv_pte_set_mode(prot,
+						       HV_PTE_MODE_UNCACHED);
+			else
+				prot = hv_pte_set_mode(prot,
+						       HV_PTE_MODE_CACHE_NO_L3);
+		} else {
+			prot = hv_pte_set_mode(prot,
+					       HV_PTE_MODE_CACHE_TILE_L3);
+			cpu = cpumask_first(&ktext_mask);
+
+			prot = ktext_set_nocache(prot);
+		}
+
+		BUG_ON(address != (unsigned long)_text);
+		pte = NULL;
+		for (; address < (unsigned long)_einittext;
+		     pfn++, address += PAGE_SIZE) {
+			pte_ofs = pte_index(address);
+			if (pte_ofs == 0) {
+				if (pte)
+					assign_pte(pmd++, pte);
+				pte = alloc_pte();
+			}
+			if (!ktext_local) {
+				prot = set_remote_cache_cpu(prot, cpu);
+				cpu = cpumask_next(cpu, &ktext_mask);
+				if (cpu == NR_CPUS)
+					cpu = cpumask_first(&ktext_mask);
+			}
+			pte[pte_ofs] = pfn_pte(pfn, prot);
+		}
+		if (pte)
+			assign_pte(pmd, pte);
+	} else {
+		pte_t pteval = pfn_pte(0, PAGE_KERNEL_EXEC);
+		pteval = pte_mkhuge(pteval);
+		if (ktext_hash) {
+			pteval = hv_pte_set_mode(pteval,
+						 HV_PTE_MODE_CACHE_HASH_L3);
+			pteval = ktext_set_nocache(pteval);
+		} else
+		if (cpumask_weight(&ktext_mask) == 1) {
+			pteval = set_remote_cache_cpu(pteval,
+					      cpumask_first(&ktext_mask));
+			pteval = hv_pte_set_mode(pteval,
+						 HV_PTE_MODE_CACHE_TILE_L3);
+			pteval = ktext_set_nocache(pteval);
+		} else if (ktext_nocache)
+			pteval = hv_pte_set_mode(pteval,
+						 HV_PTE_MODE_UNCACHED);
+		else
+			pteval = hv_pte_set_mode(pteval,
+						 HV_PTE_MODE_CACHE_NO_L3);
+		for (; address < (unsigned long)_einittext;
+		     pfn += PFN_DOWN(HPAGE_SIZE), address += HPAGE_SIZE)
+			*(pte_t *)(pmd++) = pfn_pte(pfn, pteval);
+	}
+
+	/* Set swapper_pgprot here so it is flushed to memory right away. */
+	swapper_pgprot = init_pgprot((unsigned long)swapper_pg_dir);
+
+	/*
+	 * Since we may be changing the caching of the stack and page
+	 * table itself, we invoke an assembly helper to do the
+	 * following steps:
+	 *
+	 *  - flush the cache so we start with an empty slate
+	 *  - install pgtables[] as the real page table
+	 *  - flush the TLB so the new page table takes effect
+	 */
+	irqmask = interrupt_mask_save_mask();
+	interrupt_mask_set_mask(-1ULL);
+	rc = flush_and_install_context(__pa(pgtables),
+				       init_pgprot((unsigned long)pgtables),
+				       __this_cpu_read(current_asid),
+				       cpumask_bits(my_cpu_mask));
+	interrupt_mask_restore_mask(irqmask);
+	BUG_ON(rc != 0);
+
+	/* Copy the page table back to the normal swapper_pg_dir. */
+	memcpy(pgd_base, pgtables, sizeof(pgtables));
+	__install_page_table(pgd_base, __this_cpu_read(current_asid),
+			     swapper_pgprot);
+
+	/*
+	 * We just read swapper_pgprot and thus brought it into the cache,
+	 * with its new home & caching mode.  When we start the other CPUs,
+	 * they're going to reference swapper_pgprot via their initial fake
+	 * VA-is-PA mappings, which cache everything locally.  At that
+	 * time, if it's in our cache with a conflicting home, the
+	 * simulator's coherence checker will complain.  So, flush it out
+	 * of our cache; we're not going to ever use it again anyway.
+	 */
+	__insn_finv(&swapper_pgprot);
+}
+
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number.
+ *
+ * On Tile, the only valid things for which we can just hand out unchecked
+ * PTEs are the kernel code and data.  Anything else might change its
+ * homing with time, and we wouldn't know to adjust the /dev/mem PTEs.
+ * Note that init_thread_union is released to heap soon after boot,
+ * so we include it in the init data.
+ *
+ * For TILE-Gx, we might want to consider allowing access to PA
+ * regions corresponding to PCI space, etc.
+ */
+int devmem_is_allowed(unsigned long pagenr)
+{
+	return pagenr < kaddr_to_pfn(_end) &&
+		!(pagenr >= kaddr_to_pfn(&init_thread_union) ||
+		  pagenr < kaddr_to_pfn(__init_end)) &&
+		!(pagenr >= kaddr_to_pfn(_sinittext) ||
+		  pagenr <= kaddr_to_pfn(_einittext-1));
+}
+
+#ifdef CONFIG_HIGHMEM
+static void __init permanent_kmaps_init(pgd_t *pgd_base)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	unsigned long vaddr;
+
+	vaddr = PKMAP_BASE;
+	page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
+
+	pgd = swapper_pg_dir + pgd_index(vaddr);
+	pud = pud_offset(pgd, vaddr);
+	pmd = pmd_offset(pud, vaddr);
+	pte = pte_offset_kernel(pmd, vaddr);
+	pkmap_page_table = pte;
+}
+#endif /* CONFIG_HIGHMEM */
+
+
+#ifndef CONFIG_64BIT
+static void __init init_free_pfn_range(unsigned long start, unsigned long end)
+{
+	unsigned long pfn;
+	struct page *page = pfn_to_page(start);
+
+	for (pfn = start; pfn < end; ) {
+		/* Optimize by freeing pages in large batches */
+		int order = __ffs(pfn);
+		int count, i;
+		struct page *p;
+
+		if (order >= MAX_ORDER)
+			order = MAX_ORDER-1;
+		count = 1 << order;
+		while (pfn + count > end) {
+			count >>= 1;
+			--order;
+		}
+		for (p = page, i = 0; i < count; ++i, ++p) {
+			__ClearPageReserved(p);
+			/*
+			 * Hacky direct set to avoid unnecessary
+			 * lock take/release for EVERY page here.
+			 */
+			p->_count.counter = 0;
+			p->_mapcount.counter = -1;
+		}
+		init_page_count(page);
+		__free_pages(page, order);
+		adjust_managed_page_count(page, count);
+
+		page += count;
+		pfn += count;
+	}
+}
+
+static void __init set_non_bootmem_pages_init(void)
+{
+	struct zone *z;
+	for_each_zone(z) {
+		unsigned long start, end;
+		int nid = z->zone_pgdat->node_id;
+#ifdef CONFIG_HIGHMEM
+		int idx = zone_idx(z);
+#endif
+
+		start = z->zone_start_pfn;
+		end = start + z->spanned_pages;
+		start = max(start, node_free_pfn[nid]);
+		start = max(start, max_low_pfn);
+
+#ifdef CONFIG_HIGHMEM
+		if (idx == ZONE_HIGHMEM)
+			totalhigh_pages += z->spanned_pages;
+#endif
+		if (kdata_huge) {
+			unsigned long percpu_pfn = node_percpu_pfn[nid];
+			if (start < percpu_pfn && end > percpu_pfn)
+				end = percpu_pfn;
+		}
+#ifdef CONFIG_PCI
+		if (start <= pci_reserve_start_pfn &&
+		    end > pci_reserve_start_pfn) {
+			if (end > pci_reserve_end_pfn)
+				init_free_pfn_range(pci_reserve_end_pfn, end);
+			end = pci_reserve_start_pfn;
+		}
+#endif
+		init_free_pfn_range(start, end);
+	}
+}
+#endif
+
+/*
+ * paging_init() sets up the page tables - note that all of lowmem is
+ * already mapped by head.S.
+ */
+void __init paging_init(void)
+{
+#ifdef __tilegx__
+	pud_t *pud;
+#endif
+	pgd_t *pgd_base = swapper_pg_dir;
+
+	kernel_physical_mapping_init(pgd_base);
+
+	/* Fixed mappings, only the page table structure has to be created. */
+	page_table_range_init(fix_to_virt(__end_of_fixed_addresses - 1),
+			      FIXADDR_TOP, pgd_base);
+
+#ifdef CONFIG_HIGHMEM
+	permanent_kmaps_init(pgd_base);
+#endif
+
+#ifdef __tilegx__
+	/*
+	 * Since GX allocates just one pmd_t array worth of vmalloc space,
+	 * we go ahead and allocate it statically here, then share it
+	 * globally.  As a result we don't have to worry about any task
+	 * changing init_mm once we get up and running, and there's no
+	 * need for e.g. vmalloc_sync_all().
+	 */
+	BUILD_BUG_ON(pgd_index(VMALLOC_START) != pgd_index(VMALLOC_END - 1));
+	pud = pud_offset(pgd_base + pgd_index(VMALLOC_START), VMALLOC_START);
+	assign_pmd(pud, alloc_pmd());
+#endif
+}
+
+
+/*
+ * Walk the kernel page tables and derive the page_home() from
+ * the PTEs, so that set_pte() can properly validate the caching
+ * of all PTEs it sees.
+ */
+void __init set_page_homes(void)
+{
+}
+
+static void __init set_max_mapnr_init(void)
+{
+#ifdef CONFIG_FLATMEM
+	max_mapnr = max_low_pfn;
+#endif
+}
+
+void __init mem_init(void)
+{
+	int i;
+#ifndef __tilegx__
+	void *last;
+#endif
+
+#ifdef CONFIG_FLATMEM
+	BUG_ON(!mem_map);
+#endif
+
+#ifdef CONFIG_HIGHMEM
+	/* check that fixmap and pkmap do not overlap */
+	if (PKMAP_ADDR(LAST_PKMAP-1) >= FIXADDR_START) {
+		pr_err("fixmap and kmap areas overlap - this will crash\n");
+		pr_err("pkstart: %lxh pkend: %lxh fixstart %lxh\n",
+		       PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP-1), FIXADDR_START);
+		BUG();
+	}
+#endif
+
+	set_max_mapnr_init();
+
+	/* this will put all bootmem onto the freelists */
+	free_all_bootmem();
+
+#ifndef CONFIG_64BIT
+	/* count all remaining LOWMEM and give all HIGHMEM to page allocator */
+	set_non_bootmem_pages_init();
+#endif
+
+	mem_init_print_info(NULL);
+
+	/*
+	 * In debug mode, dump some interesting memory mappings.
+	 */
+#ifdef CONFIG_HIGHMEM
+	printk(KERN_DEBUG "  KMAP    %#lx - %#lx\n",
+	       FIXADDR_START, FIXADDR_TOP + PAGE_SIZE - 1);
+	printk(KERN_DEBUG "  PKMAP   %#lx - %#lx\n",
+	       PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP) - 1);
+#endif
+	printk(KERN_DEBUG "  VMALLOC %#lx - %#lx\n",
+	       _VMALLOC_START, _VMALLOC_END - 1);
+#ifdef __tilegx__
+	for (i = MAX_NUMNODES-1; i >= 0; --i) {
+		struct pglist_data *node = &node_data[i];
+		if (node->node_present_pages) {
+			unsigned long start = (unsigned long)
+				pfn_to_kaddr(node->node_start_pfn);
+			unsigned long end = start +
+				(node->node_present_pages << PAGE_SHIFT);
+			printk(KERN_DEBUG "  MEM%d    %#lx - %#lx\n",
+			       i, start, end - 1);
+		}
+	}
+#else
+	last = high_memory;
+	for (i = MAX_NUMNODES-1; i >= 0; --i) {
+		if ((unsigned long)vbase_map[i] != -1UL) {
+			printk(KERN_DEBUG "  LOWMEM%d %#lx - %#lx\n",
+			       i, (unsigned long) (vbase_map[i]),
+			       (unsigned long) (last-1));
+			last = vbase_map[i];
+		}
+	}
+#endif
+
+#ifndef __tilegx__
+	/*
+	 * Convert from using one lock for all atomic operations to
+	 * one per cpu.
+	 */
+	__init_atomic_per_cpu();
+#endif
+}
+
+/*
+ * this is for the non-NUMA, single node SMP system case.
+ * Specifically, in the case of x86, we will always add
+ * memory to the highmem for now.
+ */
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+int arch_add_memory(u64 start, u64 size)
+{
+	struct pglist_data *pgdata = &contig_page_data;
+	struct zone *zone = pgdata->node_zones + MAX_NR_ZONES-1;
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long nr_pages = size >> PAGE_SHIFT;
+
+	return __add_pages(zone, start_pfn, nr_pages);
+}
+
+int remove_memory(u64 start, u64 size)
+{
+	return -EINVAL;
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int arch_remove_memory(u64 start, u64 size)
+{
+	/* TODO */
+	return -EBUSY;
+}
+#endif
+#endif
+
+struct kmem_cache *pgd_cache;
+
+void __init pgtable_cache_init(void)
+{
+	pgd_cache = kmem_cache_create("pgd", SIZEOF_PGD, SIZEOF_PGD, 0, NULL);
+	if (!pgd_cache)
+		panic("pgtable_cache_init(): Cannot create pgd cache");
+}
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+static long __write_once initfree;
+#else
+static long __write_once initfree = 1;
+#endif
+
+/* Select whether to free (1) or mark unusable (0) the __init pages. */
+static int __init set_initfree(char *str)
+{
+	long val;
+	if (kstrtol(str, 0, &val) == 0) {
+		initfree = val;
+		pr_info("initfree: %s free init pages\n",
+			initfree ? "will" : "won't");
+	}
+	return 1;
+}
+__setup("initfree=", set_initfree);
+
+static void free_init_pages(char *what, unsigned long begin, unsigned long end)
+{
+	unsigned long addr = (unsigned long) begin;
+
+	if (kdata_huge && !initfree) {
+		pr_warn("Warning: ignoring initfree=0: incompatible with kdata=huge\n");
+		initfree = 1;
+	}
+	end = (end + PAGE_SIZE - 1) & PAGE_MASK;
+	local_flush_tlb_pages(NULL, begin, PAGE_SIZE, end - begin);
+	for (addr = begin; addr < end; addr += PAGE_SIZE) {
+		/*
+		 * Note we just reset the home here directly in the
+		 * page table.  We know this is safe because our caller
+		 * just flushed the caches on all the other cpus,
+		 * and they won't be touching any of these pages.
+		 */
+		int pfn = kaddr_to_pfn((void *)addr);
+		struct page *page = pfn_to_page(pfn);
+		pte_t *ptep = virt_to_kpte(addr);
+		if (!initfree) {
+			/*
+			 * If debugging page accesses then do not free
+			 * this memory but mark them not present - any
+			 * buggy init-section access will create a
+			 * kernel page fault:
+			 */
+			pte_clear(&init_mm, addr, ptep);
+			continue;
+		}
+		if (pte_huge(*ptep))
+			BUG_ON(!kdata_huge);
+		else
+			set_pte_at(&init_mm, addr, ptep,
+				   pfn_pte(pfn, PAGE_KERNEL));
+		memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
+		free_reserved_page(page);
+	}
+	pr_info("Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
+}
+
+void free_initmem(void)
+{
+	const unsigned long text_delta = MEM_SV_START - PAGE_OFFSET;
+
+	/*
+	 * Evict the cache on all cores to avoid incoherence.
+	 * We are guaranteed that no one will touch the init pages any more.
+	 */
+	homecache_evict(&cpu_cacheable_map);
+
+	/* Free the data pages that we won't use again after init. */
+	free_init_pages("unused kernel data",
+			(unsigned long)__init_begin,
+			(unsigned long)__init_end);
+
+	/*
+	 * Free the pages mapped from 0xc0000000 that correspond to code
+	 * pages from MEM_SV_START that we won't use again after init.
+	 */
+	free_init_pages("unused kernel text",
+			(unsigned long)_sinittext - text_delta,
+			(unsigned long)_einittext - text_delta);
+	/* Do a global TLB flush so everyone sees the changes. */
+	flush_tlb_all();
+}