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Diffstat (limited to 'arch/tile/mm/init.c')
| -rw-r--r-- | arch/tile/mm/init.c | 983 |
1 files changed, 983 insertions, 0 deletions
diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c new file mode 100644 index 000000000..5bd252e3f --- /dev/null +++ b/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(); +} |