1c52d0d30SDavid Daney /* 2ebb5e78cSAlex Smith * Copyright (C) 2015 Imagination Technologies 3ebb5e78cSAlex Smith * Author: Alex Smith <alex.smith@imgtec.com> 4c52d0d30SDavid Daney * 5ebb5e78cSAlex Smith * This program is free software; you can redistribute it and/or modify it 6ebb5e78cSAlex Smith * under the terms of the GNU General Public License as published by the 7ebb5e78cSAlex Smith * Free Software Foundation; either version 2 of the License, or (at your 8ebb5e78cSAlex Smith * option) any later version. 9c52d0d30SDavid Daney */ 10c52d0d30SDavid Daney 11c52d0d30SDavid Daney #include <linux/binfmts.h> 12c52d0d30SDavid Daney #include <linux/elf.h> 13ebb5e78cSAlex Smith #include <linux/err.h> 14ebb5e78cSAlex Smith #include <linux/init.h> 15a7f4df4eSAlex Smith #include <linux/ioport.h> 16a7f4df4eSAlex Smith #include <linux/irqchip/mips-gic.h> 17ebb5e78cSAlex Smith #include <linux/mm.h> 18ebb5e78cSAlex Smith #include <linux/sched.h> 19ebb5e78cSAlex Smith #include <linux/slab.h> 20a7f4df4eSAlex Smith #include <linux/timekeeper_internal.h> 21c52d0d30SDavid Daney 22ebb5e78cSAlex Smith #include <asm/abi.h> 23c52d0d30SDavid Daney #include <asm/vdso.h> 24ebb5e78cSAlex Smith 25ebb5e78cSAlex Smith /* Kernel-provided data used by the VDSO. */ 26ebb5e78cSAlex Smith static union mips_vdso_data vdso_data __page_aligned_data; 27c52d0d30SDavid Daney 28c52d0d30SDavid Daney /* 29a7f4df4eSAlex Smith * Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as 30ebb5e78cSAlex Smith * what we map and where within the area they are mapped is determined at 31ebb5e78cSAlex Smith * runtime. 32c52d0d30SDavid Daney */ 33ebb5e78cSAlex Smith static struct page *no_pages[] = { NULL }; 34ebb5e78cSAlex Smith static struct vm_special_mapping vdso_vvar_mapping = { 35ebb5e78cSAlex Smith .name = "[vvar]", 36ebb5e78cSAlex Smith .pages = no_pages, 37ebb5e78cSAlex Smith }; 38c52d0d30SDavid Daney 39ebb5e78cSAlex Smith static void __init init_vdso_image(struct mips_vdso_image *image) 40c52d0d30SDavid Daney { 41ebb5e78cSAlex Smith unsigned long num_pages, i; 42554af0c3SJames Hogan unsigned long data_pfn; 43ebb5e78cSAlex Smith 44ebb5e78cSAlex Smith BUG_ON(!PAGE_ALIGNED(image->data)); 45ebb5e78cSAlex Smith BUG_ON(!PAGE_ALIGNED(image->size)); 46ebb5e78cSAlex Smith 47ebb5e78cSAlex Smith num_pages = image->size / PAGE_SIZE; 48ebb5e78cSAlex Smith 49554af0c3SJames Hogan data_pfn = __phys_to_pfn(__pa_symbol(image->data)); 50554af0c3SJames Hogan for (i = 0; i < num_pages; i++) 51554af0c3SJames Hogan image->mapping.pages[i] = pfn_to_page(data_pfn + i); 52c52d0d30SDavid Daney } 53c52d0d30SDavid Daney 54c52d0d30SDavid Daney static int __init init_vdso(void) 55c52d0d30SDavid Daney { 56ebb5e78cSAlex Smith init_vdso_image(&vdso_image); 57c52d0d30SDavid Daney 58ebb5e78cSAlex Smith #ifdef CONFIG_MIPS32_O32 59ebb5e78cSAlex Smith init_vdso_image(&vdso_image_o32); 60c52d0d30SDavid Daney #endif 61c52d0d30SDavid Daney 62ebb5e78cSAlex Smith #ifdef CONFIG_MIPS32_N32 63ebb5e78cSAlex Smith init_vdso_image(&vdso_image_n32); 64ebb5e78cSAlex Smith #endif 65c52d0d30SDavid Daney 66c52d0d30SDavid Daney return 0; 67c52d0d30SDavid Daney } 681ed84537SDavid Daney subsys_initcall(init_vdso); 69c52d0d30SDavid Daney 70a7f4df4eSAlex Smith void update_vsyscall(struct timekeeper *tk) 71a7f4df4eSAlex Smith { 72a7f4df4eSAlex Smith vdso_data_write_begin(&vdso_data); 73a7f4df4eSAlex Smith 74a7f4df4eSAlex Smith vdso_data.xtime_sec = tk->xtime_sec; 75a7f4df4eSAlex Smith vdso_data.xtime_nsec = tk->tkr_mono.xtime_nsec; 76a7f4df4eSAlex Smith vdso_data.wall_to_mono_sec = tk->wall_to_monotonic.tv_sec; 77a7f4df4eSAlex Smith vdso_data.wall_to_mono_nsec = tk->wall_to_monotonic.tv_nsec; 78a7f4df4eSAlex Smith vdso_data.cs_shift = tk->tkr_mono.shift; 79a7f4df4eSAlex Smith 80a7f4df4eSAlex Smith vdso_data.clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode; 81a7f4df4eSAlex Smith if (vdso_data.clock_mode != VDSO_CLOCK_NONE) { 82a7f4df4eSAlex Smith vdso_data.cs_mult = tk->tkr_mono.mult; 83a7f4df4eSAlex Smith vdso_data.cs_cycle_last = tk->tkr_mono.cycle_last; 84a7f4df4eSAlex Smith vdso_data.cs_mask = tk->tkr_mono.mask; 85a7f4df4eSAlex Smith } 86a7f4df4eSAlex Smith 87a7f4df4eSAlex Smith vdso_data_write_end(&vdso_data); 88a7f4df4eSAlex Smith } 89a7f4df4eSAlex Smith 90a7f4df4eSAlex Smith void update_vsyscall_tz(void) 91a7f4df4eSAlex Smith { 92a7f4df4eSAlex Smith if (vdso_data.clock_mode != VDSO_CLOCK_NONE) { 93a7f4df4eSAlex Smith vdso_data.tz_minuteswest = sys_tz.tz_minuteswest; 94a7f4df4eSAlex Smith vdso_data.tz_dsttime = sys_tz.tz_dsttime; 95a7f4df4eSAlex Smith } 96a7f4df4eSAlex Smith } 97a7f4df4eSAlex Smith 98c52d0d30SDavid Daney int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 99c52d0d30SDavid Daney { 100ebb5e78cSAlex Smith struct mips_vdso_image *image = current->thread.abi->vdso; 101c52d0d30SDavid Daney struct mm_struct *mm = current->mm; 102a7f4df4eSAlex Smith unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr; 103ebb5e78cSAlex Smith struct vm_area_struct *vma; 104a7f4df4eSAlex Smith struct resource gic_res; 105ebb5e78cSAlex Smith int ret; 106c52d0d30SDavid Daney 10769048176SMichal Hocko if (down_write_killable(&mm->mmap_sem)) 10869048176SMichal Hocko return -EINTR; 109c52d0d30SDavid Daney 110432c6bacSPaul Burton /* Map delay slot emulation page */ 111432c6bacSPaul Burton base = mmap_region(NULL, STACK_TOP, PAGE_SIZE, 112432c6bacSPaul Burton VM_READ|VM_WRITE|VM_EXEC| 113432c6bacSPaul Burton VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, 114432c6bacSPaul Burton 0); 115432c6bacSPaul Burton if (IS_ERR_VALUE(base)) { 116432c6bacSPaul Burton ret = base; 117432c6bacSPaul Burton goto out; 118432c6bacSPaul Burton } 119432c6bacSPaul Burton 120a7f4df4eSAlex Smith /* 121a7f4df4eSAlex Smith * Determine total area size. This includes the VDSO data itself, the 122a7f4df4eSAlex Smith * data page, and the GIC user page if present. Always create a mapping 123a7f4df4eSAlex Smith * for the GIC user area if the GIC is present regardless of whether it 124a7f4df4eSAlex Smith * is the current clocksource, in case it comes into use later on. We 125a7f4df4eSAlex Smith * only map a page even though the total area is 64K, as we only need 126a7f4df4eSAlex Smith * the counter registers at the start. 127a7f4df4eSAlex Smith */ 128a7f4df4eSAlex Smith gic_size = gic_present ? PAGE_SIZE : 0; 129a7f4df4eSAlex Smith vvar_size = gic_size + PAGE_SIZE; 130a7f4df4eSAlex Smith size = vvar_size + image->size; 131a7f4df4eSAlex Smith 132a7f4df4eSAlex Smith base = get_unmapped_area(NULL, 0, size, 0, 0); 133ebb5e78cSAlex Smith if (IS_ERR_VALUE(base)) { 134ebb5e78cSAlex Smith ret = base; 135ebb5e78cSAlex Smith goto out; 136c52d0d30SDavid Daney } 137c52d0d30SDavid Daney 138a7f4df4eSAlex Smith data_addr = base + gic_size; 139a7f4df4eSAlex Smith vdso_addr = data_addr + PAGE_SIZE; 140ebb5e78cSAlex Smith 141a7f4df4eSAlex Smith vma = _install_special_mapping(mm, base, vvar_size, 142ebb5e78cSAlex Smith VM_READ | VM_MAYREAD, 143ebb5e78cSAlex Smith &vdso_vvar_mapping); 144ebb5e78cSAlex Smith if (IS_ERR(vma)) { 145ebb5e78cSAlex Smith ret = PTR_ERR(vma); 146ebb5e78cSAlex Smith goto out; 147ebb5e78cSAlex Smith } 148ebb5e78cSAlex Smith 149a7f4df4eSAlex Smith /* Map GIC user page. */ 150a7f4df4eSAlex Smith if (gic_size) { 151a7f4df4eSAlex Smith ret = gic_get_usm_range(&gic_res); 152a7f4df4eSAlex Smith if (ret) 153a7f4df4eSAlex Smith goto out; 154a7f4df4eSAlex Smith 155a7f4df4eSAlex Smith ret = io_remap_pfn_range(vma, base, 156a7f4df4eSAlex Smith gic_res.start >> PAGE_SHIFT, 157a7f4df4eSAlex Smith gic_size, 158a7f4df4eSAlex Smith pgprot_noncached(PAGE_READONLY)); 159a7f4df4eSAlex Smith if (ret) 160a7f4df4eSAlex Smith goto out; 161a7f4df4eSAlex Smith } 162a7f4df4eSAlex Smith 163ebb5e78cSAlex Smith /* Map data page. */ 164a7f4df4eSAlex Smith ret = remap_pfn_range(vma, data_addr, 165ebb5e78cSAlex Smith virt_to_phys(&vdso_data) >> PAGE_SHIFT, 166ebb5e78cSAlex Smith PAGE_SIZE, PAGE_READONLY); 167ebb5e78cSAlex Smith if (ret) 168ebb5e78cSAlex Smith goto out; 169ebb5e78cSAlex Smith 170ebb5e78cSAlex Smith /* Map VDSO image. */ 171ebb5e78cSAlex Smith vma = _install_special_mapping(mm, vdso_addr, image->size, 172c52d0d30SDavid Daney VM_READ | VM_EXEC | 173909af768SJason Baron VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, 174ebb5e78cSAlex Smith &image->mapping); 175ebb5e78cSAlex Smith if (IS_ERR(vma)) { 176ebb5e78cSAlex Smith ret = PTR_ERR(vma); 177ebb5e78cSAlex Smith goto out; 178c52d0d30SDavid Daney } 179c52d0d30SDavid Daney 180ebb5e78cSAlex Smith mm->context.vdso = (void *)vdso_addr; 181ebb5e78cSAlex Smith ret = 0; 182ebb5e78cSAlex Smith 183ebb5e78cSAlex Smith out: 184ebb5e78cSAlex Smith up_write(&mm->mmap_sem); 185ebb5e78cSAlex Smith return ret; 186c52d0d30SDavid Daney } 187