// SPDX-License-Identifier: GPL-2.0 /* * Initialize MMU support. * * Copyright (C) 1998-2003 Hewlett-Packard Co * David Mosberger-Tang */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern void ia64_tlb_init (void); unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL; struct page *zero_page_memmap_ptr; /* map entry for zero page */ EXPORT_SYMBOL(zero_page_memmap_ptr); void __ia64_sync_icache_dcache (pte_t pte) { unsigned long addr; struct page *page; page = pte_page(pte); addr = (unsigned long) page_address(page); if (test_bit(PG_arch_1, &page->flags)) return; /* i-cache is already coherent with d-cache */ flush_icache_range(addr, addr + page_size(page)); set_bit(PG_arch_1, &page->flags); /* mark page as clean */ } /* * Since DMA is i-cache coherent, any (complete) pages that were written via * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to * flush them when they get mapped into an executable vm-area. */ void arch_dma_mark_clean(phys_addr_t paddr, size_t size) { unsigned long pfn = PHYS_PFN(paddr); do { set_bit(PG_arch_1, &pfn_to_page(pfn)->flags); } while (++pfn <= PHYS_PFN(paddr + size - 1)); } inline void ia64_set_rbs_bot (void) { unsigned long stack_size = rlimit_max(RLIMIT_STACK) & -16; if (stack_size > MAX_USER_STACK_SIZE) stack_size = MAX_USER_STACK_SIZE; current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size); } /* * This performs some platform-dependent address space initialization. * On IA-64, we want to setup the VM area for the register backing * store (which grows upwards) and install the gateway page which is * used for signal trampolines, etc. */ void ia64_init_addr_space (void) { struct vm_area_struct *vma; ia64_set_rbs_bot(); /* * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore * the problem. When the process attempts to write to the register backing store * for the first time, it will get a SEGFAULT in this case. */ vma = vm_area_alloc(current->mm); if (vma) { vma_set_anonymous(vma); vma->vm_start = current->thread.rbs_bot & PAGE_MASK; vma->vm_end = vma->vm_start + PAGE_SIZE; vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT; vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); mmap_write_lock(current->mm); if (insert_vm_struct(current->mm, vma)) { mmap_write_unlock(current->mm); vm_area_free(vma); return; } mmap_write_unlock(current->mm); } /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */ if (!(current->personality & MMAP_PAGE_ZERO)) { vma = vm_area_alloc(current->mm); if (vma) { vma_set_anonymous(vma); vma->vm_end = PAGE_SIZE; vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT); vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO | VM_DONTEXPAND | VM_DONTDUMP; mmap_write_lock(current->mm); if (insert_vm_struct(current->mm, vma)) { mmap_write_unlock(current->mm); vm_area_free(vma); return; } mmap_write_unlock(current->mm); } } } void free_initmem (void) { free_reserved_area(ia64_imva(__init_begin), ia64_imva(__init_end), -1, "unused kernel"); } void __init free_initrd_mem (unsigned long start, unsigned long end) { /* * EFI uses 4KB pages while the kernel can use 4KB or bigger. * Thus EFI and the kernel may have different page sizes. It is * therefore possible to have the initrd share the same page as * the end of the kernel (given current setup). * * To avoid freeing/using the wrong page (kernel sized) we: * - align up the beginning of initrd * - align down the end of initrd * * | | * |=============| a000 * | | * | | * | | 9000 * |/////////////| * |/////////////| * |=============| 8000 * |///INITRD////| * |/////////////| * |/////////////| 7000 * | | * |KKKKKKKKKKKKK| * |=============| 6000 * |KKKKKKKKKKKKK| * |KKKKKKKKKKKKK| * K=kernel using 8KB pages * * In this example, we must free page 8000 ONLY. So we must align up * initrd_start and keep initrd_end as is. */ start = PAGE_ALIGN(start); end = end & PAGE_MASK; if (start < end) printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10); for (; start < end; start += PAGE_SIZE) { if (!virt_addr_valid(start)) continue; free_reserved_page(virt_to_page(start)); } } /* * This installs a clean page in the kernel's page table. */ static struct page * __init put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot) { pgd_t *pgd; p4d_t *p4d; pud_t *pud; pmd_t *pmd; pte_t *pte; pgd = pgd_offset_k(address); /* note: this is NOT pgd_offset()! */ { p4d = p4d_alloc(&init_mm, pgd, address); if (!p4d) goto out; pud = pud_alloc(&init_mm, p4d, address); if (!pud) goto out; pmd = pmd_alloc(&init_mm, pud, address); if (!pmd) goto out; pte = pte_alloc_kernel(pmd, address); if (!pte) goto out; if (!pte_none(*pte)) goto out; set_pte(pte, mk_pte(page, pgprot)); } out: /* no need for flush_tlb */ return page; } static void __init setup_gate (void) { struct page *page; /* * Map the gate page twice: once read-only to export the ELF * headers etc. and once execute-only page to enable * privilege-promotion via "epc": */ page = virt_to_page(ia64_imva(__start_gate_section)); put_kernel_page(page, GATE_ADDR, PAGE_READONLY); #ifdef HAVE_BUGGY_SEGREL page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE)); put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE); #else put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE); /* Fill in the holes (if any) with read-only zero pages: */ { unsigned long addr; for (addr = GATE_ADDR + PAGE_SIZE; addr < GATE_ADDR + PERCPU_PAGE_SIZE; addr += PAGE_SIZE) { put_kernel_page(ZERO_PAGE(0), addr, PAGE_READONLY); put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE, PAGE_READONLY); } } #endif ia64_patch_gate(); } static struct vm_area_struct gate_vma; static int __init gate_vma_init(void) { vma_init(&gate_vma, NULL); gate_vma.vm_start = FIXADDR_USER_START; gate_vma.vm_end = FIXADDR_USER_END; gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC; gate_vma.vm_page_prot = __P101; return 0; } __initcall(gate_vma_init); struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { return &gate_vma; } int in_gate_area_no_mm(unsigned long addr) { if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END)) return 1; return 0; } int in_gate_area(struct mm_struct *mm, unsigned long addr) { return in_gate_area_no_mm(addr); } void ia64_mmu_init(void *my_cpu_data) { unsigned long pta, impl_va_bits; extern void tlb_init(void); #ifdef CONFIG_DISABLE_VHPT # define VHPT_ENABLE_BIT 0 #else # define VHPT_ENABLE_BIT 1 #endif /* * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped * address space. The IA-64 architecture guarantees that at least 50 bits of * virtual address space are implemented but if we pick a large enough page size * (e.g., 64KB), the mapped address space is big enough that it will overlap with * VMLPT. I assume that once we run on machines big enough to warrant 64KB pages, * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a * problem in practice. Alternatively, we could truncate the top of the mapped * address space to not permit mappings that would overlap with the VMLPT. * --davidm 00/12/06 */ # define pte_bits 3 # define mapped_space_bits (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT) /* * The virtual page table has to cover the entire implemented address space within * a region even though not all of this space may be mappable. The reason for * this is that the Access bit and Dirty bit fault handlers perform * non-speculative accesses to the virtual page table, so the address range of the * virtual page table itself needs to be covered by virtual page table. */ # define vmlpt_bits (impl_va_bits - PAGE_SHIFT + pte_bits) # define POW2(n) (1ULL << (n)) impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61))); if (impl_va_bits < 51 || impl_va_bits > 61) panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1); /* * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need, * which must fit into "vmlpt_bits - pte_bits" slots. Second half of * the test makes sure that our mapped space doesn't overlap the * unimplemented hole in the middle of the region. */ if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) || (mapped_space_bits > impl_va_bits - 1)) panic("Cannot build a big enough virtual-linear page table" " to cover mapped address space.\n" " Try using a smaller page size.\n"); /* place the VMLPT at the end of each page-table mapped region: */ pta = POW2(61) - POW2(vmlpt_bits); /* * Set the (virtually mapped linear) page table address. Bit * 8 selects between the short and long format, bits 2-7 the * size of the table, and bit 0 whether the VHPT walker is * enabled. */ ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT); ia64_tlb_init(); #ifdef CONFIG_HUGETLB_PAGE ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2); ia64_srlz_d(); #endif } int __init register_active_ranges(u64 start, u64 len, int nid) { u64 end = start + len; #ifdef CONFIG_KEXEC if (start > crashk_res.start && start < crashk_res.end) start = crashk_res.end; if (end > crashk_res.start && end < crashk_res.end) end = crashk_res.start; #endif if (start < end) memblock_add_node(__pa(start), end - start, nid); return 0; } int find_max_min_low_pfn (u64 start, u64 end, void *arg) { unsigned long pfn_start, pfn_end; #ifdef CONFIG_FLATMEM pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT; pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT; #else pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT; pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT; #endif min_low_pfn = min(min_low_pfn, pfn_start); max_low_pfn = max(max_low_pfn, pfn_end); return 0; } /* * Boot command-line option "nolwsys" can be used to disable the use of any light-weight * system call handler. When this option is in effect, all fsyscalls will end up bubbling * down into the kernel and calling the normal (heavy-weight) syscall handler. This is * useful for performance testing, but conceivably could also come in handy for debugging * purposes. */ static int nolwsys __initdata; static int __init nolwsys_setup (char *s) { nolwsys = 1; return 1; } __setup("nolwsys", nolwsys_setup); void __init mem_init (void) { int i; BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE); BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE); BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE); /* * This needs to be called _after_ the command line has been parsed but * _before_ any drivers that may need the PCI DMA interface are * initialized or bootmem has been freed. */ do { #ifdef CONFIG_INTEL_IOMMU detect_intel_iommu(); if (iommu_detected) break; #endif #ifdef CONFIG_SWIOTLB swiotlb_init(1); #endif } while (0); #ifdef CONFIG_FLATMEM BUG_ON(!mem_map); #endif set_max_mapnr(max_low_pfn); high_memory = __va(max_low_pfn * PAGE_SIZE); memblock_free_all(); /* * For fsyscall entrpoints with no light-weight handler, use the ordinary * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry * code can tell them apart. */ for (i = 0; i < NR_syscalls; ++i) { extern unsigned long fsyscall_table[NR_syscalls]; extern unsigned long sys_call_table[NR_syscalls]; if (!fsyscall_table[i] || nolwsys) fsyscall_table[i] = sys_call_table[i] | 1; } setup_gate(); } #ifdef CONFIG_MEMORY_HOTPLUG int arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params) { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; int ret; if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot)) return -EINVAL; ret = __add_pages(nid, start_pfn, nr_pages, params); if (ret) printk("%s: Problem encountered in __add_pages() as ret=%d\n", __func__, ret); return ret; } void arch_remove_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap) { unsigned long start_pfn = start >> PAGE_SHIFT; unsigned long nr_pages = size >> PAGE_SHIFT; __remove_pages(start_pfn, nr_pages, altmap); } #endif