blk: rq_data_dir() should not return a boolean
[cris-mirror.git] / arch / arm64 / kernel / vdso.c
blob97bc68f4c689f28eac7188f5e0b792b5293c37da
1 /*
2 * VDSO implementation for AArch64 and vector page setup for AArch32.
4 * Copyright (C) 2012 ARM Limited
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 * Author: Will Deacon <will.deacon@arm.com>
21 #include <linux/kernel.h>
22 #include <linux/clocksource.h>
23 #include <linux/elf.h>
24 #include <linux/err.h>
25 #include <linux/errno.h>
26 #include <linux/gfp.h>
27 #include <linux/mm.h>
28 #include <linux/sched.h>
29 #include <linux/signal.h>
30 #include <linux/slab.h>
31 #include <linux/timekeeper_internal.h>
32 #include <linux/vmalloc.h>
34 #include <asm/cacheflush.h>
35 #include <asm/signal32.h>
36 #include <asm/vdso.h>
37 #include <asm/vdso_datapage.h>
39 extern char vdso_start, vdso_end;
40 static unsigned long vdso_pages;
41 static struct page **vdso_pagelist;
44 * The vDSO data page.
46 static union {
47 struct vdso_data data;
48 u8 page[PAGE_SIZE];
49 } vdso_data_store __page_aligned_data;
50 struct vdso_data *vdso_data = &vdso_data_store.data;
52 #ifdef CONFIG_COMPAT
54 * Create and map the vectors page for AArch32 tasks.
56 static struct page *vectors_page[1];
58 static int alloc_vectors_page(void)
60 extern char __kuser_helper_start[], __kuser_helper_end[];
61 extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
63 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
64 int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;
65 unsigned long vpage;
67 vpage = get_zeroed_page(GFP_ATOMIC);
69 if (!vpage)
70 return -ENOMEM;
72 /* kuser helpers */
73 memcpy((void *)vpage + 0x1000 - kuser_sz, __kuser_helper_start,
74 kuser_sz);
76 /* sigreturn code */
77 memcpy((void *)vpage + AARCH32_KERN_SIGRET_CODE_OFFSET,
78 __aarch32_sigret_code_start, sigret_sz);
80 flush_icache_range(vpage, vpage + PAGE_SIZE);
81 vectors_page[0] = virt_to_page(vpage);
83 return 0;
85 arch_initcall(alloc_vectors_page);
87 int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
89 struct mm_struct *mm = current->mm;
90 unsigned long addr = AARCH32_VECTORS_BASE;
91 static struct vm_special_mapping spec = {
92 .name = "[vectors]",
93 .pages = vectors_page,
96 void *ret;
98 down_write(&mm->mmap_sem);
99 current->mm->context.vdso = (void *)addr;
101 /* Map vectors page at the high address. */
102 ret = _install_special_mapping(mm, addr, PAGE_SIZE,
103 VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC,
104 &spec);
106 up_write(&mm->mmap_sem);
108 return PTR_ERR_OR_ZERO(ret);
110 #endif /* CONFIG_COMPAT */
112 static struct vm_special_mapping vdso_spec[2];
114 static int __init vdso_init(void)
116 int i;
118 if (memcmp(&vdso_start, "\177ELF", 4)) {
119 pr_err("vDSO is not a valid ELF object!\n");
120 return -EINVAL;
123 vdso_pages = (&vdso_end - &vdso_start) >> PAGE_SHIFT;
124 pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n",
125 vdso_pages + 1, vdso_pages, &vdso_start, 1L, vdso_data);
127 /* Allocate the vDSO pagelist, plus a page for the data. */
128 vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *),
129 GFP_KERNEL);
130 if (vdso_pagelist == NULL)
131 return -ENOMEM;
133 /* Grab the vDSO data page. */
134 vdso_pagelist[0] = virt_to_page(vdso_data);
136 /* Grab the vDSO code pages. */
137 for (i = 0; i < vdso_pages; i++)
138 vdso_pagelist[i + 1] = virt_to_page(&vdso_start + i * PAGE_SIZE);
140 /* Populate the special mapping structures */
141 vdso_spec[0] = (struct vm_special_mapping) {
142 .name = "[vvar]",
143 .pages = vdso_pagelist,
146 vdso_spec[1] = (struct vm_special_mapping) {
147 .name = "[vdso]",
148 .pages = &vdso_pagelist[1],
151 return 0;
153 arch_initcall(vdso_init);
155 int arch_setup_additional_pages(struct linux_binprm *bprm,
156 int uses_interp)
158 struct mm_struct *mm = current->mm;
159 unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
160 void *ret;
162 vdso_text_len = vdso_pages << PAGE_SHIFT;
163 /* Be sure to map the data page */
164 vdso_mapping_len = vdso_text_len + PAGE_SIZE;
166 down_write(&mm->mmap_sem);
167 vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
168 if (IS_ERR_VALUE(vdso_base)) {
169 ret = ERR_PTR(vdso_base);
170 goto up_fail;
172 ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
173 VM_READ|VM_MAYREAD,
174 &vdso_spec[0]);
175 if (IS_ERR(ret))
176 goto up_fail;
178 vdso_base += PAGE_SIZE;
179 mm->context.vdso = (void *)vdso_base;
180 ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
181 VM_READ|VM_EXEC|
182 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
183 &vdso_spec[1]);
184 if (IS_ERR(ret))
185 goto up_fail;
188 up_write(&mm->mmap_sem);
189 return 0;
191 up_fail:
192 mm->context.vdso = NULL;
193 up_write(&mm->mmap_sem);
194 return PTR_ERR(ret);
198 * Update the vDSO data page to keep in sync with kernel timekeeping.
200 void update_vsyscall(struct timekeeper *tk)
202 u32 use_syscall = strcmp(tk->tkr_mono.clock->name, "arch_sys_counter");
204 ++vdso_data->tb_seq_count;
205 smp_wmb();
207 vdso_data->use_syscall = use_syscall;
208 vdso_data->xtime_coarse_sec = tk->xtime_sec;
209 vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>
210 tk->tkr_mono.shift;
211 vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec;
212 vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec;
214 if (!use_syscall) {
215 vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last;
216 vdso_data->xtime_clock_sec = tk->xtime_sec;
217 vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec;
218 vdso_data->cs_mult = tk->tkr_mono.mult;
219 vdso_data->cs_shift = tk->tkr_mono.shift;
222 smp_wmb();
223 ++vdso_data->tb_seq_count;
226 void update_vsyscall_tz(void)
228 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
229 vdso_data->tz_dsttime = sys_tz.tz_dsttime;