FROMLIST: [PATCH v5 11/12] lib: vdso: Add support for CLOCK_BOOTTIME

[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / arch / arm / kernel / vdso.c

diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index 54a5aeab988d3526657b8e3089942ca8cfe4fe5e..e50a72ca08f12e6568c41906cd8466233e32ffe5 100644 (file)
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c
@@ -17,6 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/cache.h>
 #include <linux/elf.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
@@ -39,7 +40,7 @@
 static struct page **vdso_text_pagelist;
 
 /* Total number of pages needed for the data and text portions of the VDSO. */
-unsigned int vdso_total_pages __read_mostly;
+unsigned int vdso_total_pages __ro_after_init;
 
 /*
  * The VDSO data page.
@@ -47,13 +48,13 @@ unsigned int vdso_total_pages __read_mostly;
 static union vdso_data_store vdso_data_store __page_aligned_data;
 static struct vdso_data *vdso_data = &vdso_data_store.data;
 
-static struct page *vdso_data_page;
-static struct vm_special_mapping vdso_data_mapping = {
+static struct page *vdso_data_page __ro_after_init;
+static const struct vm_special_mapping vdso_data_mapping = {
        .name = "[vvar]",
        .pages = &vdso_data_page,
 };
 
-static struct vm_special_mapping vdso_text_mapping = {
+static struct vm_special_mapping vdso_text_mapping __ro_after_init = {
        .name = "[vdso]",
 };
 
@@ -67,7 +68,7 @@ struct elfinfo {
 /* Cached result of boot-time check for whether the arch timer exists,
  * and if so, whether the virtual counter is useable.
  */
-static bool cntvct_ok __read_mostly;
+static bool cntvct_ok __ro_after_init;
 
 static bool __init cntvct_functional(void)
 {
@@ -170,6 +171,7 @@ static void __init patch_vdso(void *ehdr)
        if (!cntvct_ok) {
                vdso_nullpatch_one(&einfo, "__vdso_gettimeofday");
                vdso_nullpatch_one(&einfo, "__vdso_clock_gettime");
+               vdso_nullpatch_one(&einfo, "__vdso_clock_getres");
        }
 }
 
@@ -224,7 +226,7 @@ static int install_vvar(struct mm_struct *mm, unsigned long addr)
                                       VM_READ | VM_MAYREAD,
                                       &vdso_data_mapping);
 
-       return IS_ERR(vma) ? PTR_ERR(vma) : 0;
+       return PTR_ERR_OR_ZERO(vma);
 }
 
 /* assumes mmap_sem is write-locked */
@@ -255,14 +257,14 @@ void arm_install_vdso(struct mm_struct *mm, unsigned long addr)
 
 static void vdso_write_begin(struct vdso_data *vdata)
 {
-       ++vdso_data->seq_count;
+       ++vdso_data->tb_seq_count;
        smp_wmb(); /* Pairs with smp_rmb in vdso_read_retry */
 }
 
 static void vdso_write_end(struct vdso_data *vdata)
 {
        smp_wmb(); /* Pairs with smp_rmb in vdso_read_begin */
-       ++vdso_data->seq_count;
+       ++vdso_data->tb_seq_count;
 }
 
 static bool tk_is_cntvct(const struct timekeeper *tk)
@@ -286,10 +288,10 @@ static bool tk_is_cntvct(const struct timekeeper *tk)
  * counter again, making it even, indicating to userspace that the
  * update is finished.
  *
- * Userspace is expected to sample seq_count before reading any other
- * fields from the data page.  If seq_count is odd, userspace is
+ * Userspace is expected to sample tb_seq_count before reading any other
+ * fields from the data page.  If tb_seq_count is odd, userspace is
  * expected to wait until it becomes even.  After copying data from
- * the page, userspace must sample seq_count again; if it has changed
+ * the page, userspace must sample tb_seq_count again; if it has changed
  * from its previous value, userspace must retry the whole sequence.
  *
  * Calls to update_vsyscall are serialized by the timekeeping core.
@@ -307,20 +309,25 @@ void update_vsyscall(struct timekeeper *tk)
 
        vdso_write_begin(vdso_data);
 
-       vdso_data->tk_is_cntvct                 = tk_is_cntvct(tk);
+       vdso_data->use_syscall                  = !tk_is_cntvct(tk);
        vdso_data->xtime_coarse_sec             = tk->xtime_sec;
        vdso_data->xtime_coarse_nsec            = (u32)(tk->tkr_mono.xtime_nsec >>
                                                        tk->tkr_mono.shift);
        vdso_data->wtm_clock_sec                = wtm->tv_sec;
        vdso_data->wtm_clock_nsec               = wtm->tv_nsec;
 
-       if (vdso_data->tk_is_cntvct) {
+       if (!vdso_data->use_syscall) {
                vdso_data->cs_cycle_last        = tk->tkr_mono.cycle_last;
+               vdso_data->raw_time_sec         = tk->raw_sec;
+               vdso_data->raw_time_nsec        = tk->tkr_raw.xtime_nsec;
                vdso_data->xtime_clock_sec      = tk->xtime_sec;
                vdso_data->xtime_clock_snsec    = tk->tkr_mono.xtime_nsec;
-               vdso_data->cs_mult              = tk->tkr_mono.mult;
+               vdso_data->cs_mono_mult         = tk->tkr_mono.mult;
+               vdso_data->cs_raw_mult          = tk->tkr_raw.mult;
+               /* tkr_mono.shift == tkr_raw.shift */
                vdso_data->cs_shift             = tk->tkr_mono.shift;
                vdso_data->cs_mask              = tk->tkr_mono.mask;
+               vdso_data->btm_nsec             = ktime_to_ns(tk->offs_boot);
        }
 
        vdso_write_end(vdso_data);