[RFC][PATCH (4/4)] new timeofday vsyscall proof of concept (v A4)
From: john stultz (johnstul_at_us.ibm.com)
Date: 04/30/05
- Previous message: john stultz: "[RFC][PATCH (3/4)] new timeofday arch specific timesource drivers (v A4)"
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To: lkml <linux-kernel@vger.kernel.org> Date: Fri, 29 Apr 2005 15:48:48 -0700
All,
This patch implements vsyscall-gettimeofday() functions for i386 and
x86-64 using the new timeofday core code. This is just a hackish proof
of concept that shows how it could be done and what interfaces are
needed to have a clean separation of the arch independent time keeping
and the very arch specific vsyscall code.
I look forward to your comments and feedback.
thanks
-john
linux-2.6.12-rc2_timeofday-vsyscall_A4.patch
===============================================
diff -Nru a/arch/i386/Kconfig b/arch/i386/Kconfig
--- a/arch/i386/Kconfig 2005-04-29 15:31:09 -07:00
+++ b/arch/i386/Kconfig 2005-04-29 15:31:09 -07:00
@@ -464,6 +464,10 @@
bool "Provide RTC interrupt"
depends on HPET_TIMER && RTC=y
+config NEWTOD_VSYSCALL
+ depends on EXPERIMENTAL
+ bool "VSYSCALL gettimeofday() interface"
+
config SMP
bool "Symmetric multi-processing support"
---help---
diff -Nru a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
--- a/arch/i386/kernel/Makefile 2005-04-29 15:31:09 -07:00
+++ b/arch/i386/kernel/Makefile 2005-04-29 15:31:09 -07:00
@@ -11,6 +11,7 @@
obj-y += cpu/
obj-$(!CONFIG_NEWTOD) += timers/
+obj-$(CONFIG_NEWTOD_VSYSCALL) += vsyscall-gtod.o
obj-$(CONFIG_ACPI_BOOT) += acpi/
obj-$(CONFIG_X86_BIOS_REBOOT) += reboot.o
obj-$(CONFIG_MCA) += mca.o
diff -Nru a/arch/i386/kernel/setup.c b/arch/i386/kernel/setup.c
--- a/arch/i386/kernel/setup.c 2005-04-29 15:31:09 -07:00
+++ b/arch/i386/kernel/setup.c 2005-04-29 15:31:09 -07:00
@@ -51,6 +51,7 @@
#include <asm/ist.h>
#include <asm/io.h>
#include <asm/tsc.h>
+#include <asm/vsyscall-gtod.h>
#include "setup_arch_pre.h"
#include <bios_ebda.h>
@@ -1525,6 +1526,7 @@
#endif
#endif
tsc_init();
+ vsyscall_init();
}
#include "setup_arch_post.h"
diff -Nru a/arch/i386/kernel/vmlinux.lds.S b/arch/i386/kernel/vmlinux.lds.S
--- a/arch/i386/kernel/vmlinux.lds.S 2005-04-29 15:31:09 -07:00
+++ b/arch/i386/kernel/vmlinux.lds.S 2005-04-29 15:31:09 -07:00
@@ -5,6 +5,8 @@
#include <asm-generic/vmlinux.lds.h>
#include <asm/thread_info.h>
#include <asm/page.h>
+#include <linux/config.h>
+#include <asm/vsyscall-gtod.h>
OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
OUTPUT_ARCH(i386)
@@ -51,6 +53,31 @@
.data.cacheline_aligned : { *(.data.cacheline_aligned) }
_edata = .; /* End of data section */
+
+/* VSYSCALL_GTOD data */
+#ifdef CONFIG_NEWTOD_VSYSCALL
+
+ /* vsyscall entry */
+ . = ALIGN(64);
+ .data.cacheline_aligned : { *(.data.cacheline_aligned) }
+
+ .vsyscall_0 VSYSCALL_GTOD_START: AT ((LOADADDR(.data.cacheline_aligned) + SIZEOF(.data.cacheline_aligned) + 4095) & ~(4095)) { *(.vsyscall_0) }
+ __vsyscall_0 = LOADADDR(.vsyscall_0);
+
+
+ /* generic gtod variables */
+ . = ALIGN(64);
+ .vsyscall_gtod_data : AT ((LOADADDR(.vsyscall_0) + SIZEOF(.vsyscall_0) + 63) & ~(63)) { *(.vsyscall_gtod_data) }
+ vsyscall_gtod_data = LOADADDR(.vsyscall_gtod_data);
+
+ . = ALIGN(16);
+ .vsyscall_gtod_lock : AT ((LOADADDR(.vsyscall_gtod_data) + SIZEOF(.vsyscall_gtod_data) + 15) & ~(15)) { *(.vsyscall_gtod_lock) }
+ vsyscall_gtod_lock = LOADADDR(.vsyscall_gtod_lock);
+
+ .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT (LOADADDR(.vsyscall_0) + 1024) { *(.vsyscall_1) }
+ . = LOADADDR(.vsyscall_0) + 4096;
+#endif
+/* END of VSYSCALL_GTOD data*/
. = ALIGN(THREAD_SIZE); /* init_task */
.data.init_task : { *(.data.init_task) }
diff -Nru a/arch/i386/kernel/vsyscall-gtod.c b/arch/i386/kernel/vsyscall-gtod.c
--- /dev/null Wed Dec 31 16:00:00 196900
+++ b/arch/i386/kernel/vsyscall-gtod.c 2005-04-29 15:31:09 -07:00
@@ -0,0 +1,193 @@
+#include <linux/time.h>
+#include <linux/timeofday.h>
+#include <linux/timesource.h>
+#include <linux/sched.h>
+#include <asm/vsyscall-gtod.h>
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/fixmap.h>
+#include <asm/msr.h>
+#include <asm/timer.h>
+#include <asm/system.h>
+#include <asm/unistd.h>
+#include <asm/errno.h>
+
+struct vsyscall_gtod_data_t {
+ struct timeval wall_time_tv;
+ struct timezone sys_tz;
+ cycle_t offset_base;
+ struct timesource_t timesource;
+};
+
+struct vsyscall_gtod_data_t vsyscall_gtod_data;
+struct vsyscall_gtod_data_t __vsyscall_gtod_data __section_vsyscall_gtod_data;
+
+seqlock_t vsyscall_gtod_lock = SEQLOCK_UNLOCKED;
+seqlock_t __vsyscall_gtod_lock __section_vsyscall_gtod_lock = SEQLOCK_UNLOCKED;
+
+int errno;
+static inline _syscall2(int,gettimeofday,struct timeval *,tv,struct timezone *,tz);
+
+static int vsyscall_mapped = 0; /* flag variable for remap_vsyscall() */
+extern struct timezone sys_tz;
+
+static inline void do_vgettimeofday(struct timeval* tv)
+{
+ cycle_t now, cycle_delta;
+ nsec_t nsec_delta;
+
+ if (__vsyscall_gtod_data.timesource.type == TIMESOURCE_FUNCTION) {
+ gettimeofday(tv, NULL);
+ return;
+ }
+
+ /* read the timeosurce and calc cycle_delta */
+ now = read_timesource(&__vsyscall_gtod_data.timesource);
+ cycle_delta = (now - __vsyscall_gtod_data.offset_base)
+ & __vsyscall_gtod_data.timesource.mask;
+
+ /* convert cycles to nsecs */
+ nsec_delta = cycle_delta * __vsyscall_gtod_data.timesource.mult;
+ nsec_delta = nsec_delta >> __vsyscall_gtod_data.timesource.shift;
+
+ /* add nsec offset to wall_time_tv */
+ *tv = __vsyscall_gtod_data.wall_time_tv;
+ do_div(nsec_delta, NSEC_PER_USEC);
+ tv->tv_usec += (unsigned long) nsec_delta;
+ while (tv->tv_usec > USEC_PER_SEC) {
+ tv->tv_sec += 1;
+ tv->tv_usec -= USEC_PER_SEC;
+ }
+}
+
+static inline void do_get_tz(struct timezone *tz)
+{
+ *tz = __vsyscall_gtod_data.sys_tz;
+}
+
+static int __vsyscall(0) asmlinkage vgettimeofday(struct timeval *tv, struct timezone *tz)
+{
+ unsigned long seq;
+ do {
+ seq = read_seqbegin(&__vsyscall_gtod_lock);
+
+ if (tv)
+ do_vgettimeofday(tv);
+ if (tz)
+ do_get_tz(tz);
+
+ } while (read_seqretry(&__vsyscall_gtod_lock, seq));
+
+ return 0;
+}
+
+static time_t __vsyscall(1) asmlinkage vtime(time_t * t)
+{
+ struct timeval tv;
+ vgettimeofday(&tv,NULL);
+ if (t)
+ *t = tv.tv_sec;
+ return tv.tv_sec;
+}
+
+struct timesource_t* curr_timesource;
+
+void arch_update_vsyscall_gtod(nsec_t wall_time, cycle_t offset_base,
+ struct timesource_t* timesource, int ntp_adj)
+{
+ unsigned long flags;
+
+ write_seqlock_irqsave(&vsyscall_gtod_lock, flags);
+
+ /* XXX - hackitty hack hack. this is terrible! */
+ if (curr_timesource != timesource) {
+ if ((timesource->type == TIMESOURCE_MMIO_32)
+ || (timesource->type == TIMESOURCE_MMIO_64)) {
+ unsigned long vaddr = (unsigned long)timesource->mmio_ptr;
+ pgd_t *pgd = pgd_offset_k(vaddr);
+ pud_t *pud = pud_offset(pgd, vaddr);
+ pmd_t *pmd = pmd_offset(pud,vaddr);
+ pte_t *pte = pte_offset_kernel(pmd, vaddr);
+ pte->pte_low |= _PAGE_USER;
+ }
+ }
+
+ /* save off wall time as timeval */
+ vsyscall_gtod_data.wall_time_tv = ns2timeval(wall_time);
+
+ /* save offset_base */
+ vsyscall_gtod_data.offset_base = offset_base;
+
+ /* copy current timesource */
+ vsyscall_gtod_data.timesource = *timesource;
+
+ /* apply ntp adjustment to timesource mult */
+ vsyscall_gtod_data.timesource.mult += ntp_adj;
+
+ /* save off current timezone */
+ vsyscall_gtod_data.sys_tz = sys_tz;
+
+ write_sequnlock_irqrestore(&vsyscall_gtod_lock, flags);
+
+}
+extern char __vsyscall_0;
+
+static void __init map_vsyscall(void)
+{
+ unsigned long physaddr_page0 = (unsigned long) &__vsyscall_0 - PAGE_OFFSET;
+
+ /* Initially we map the VSYSCALL page w/ PAGE_KERNEL permissions to
+ * keep the alternate_instruction code from bombing out when it
+ * changes the seq_lock memory barriers in vgettimeofday()
+ */
+ __set_fixmap(FIX_VSYSCALL_GTOD_FIRST_PAGE, physaddr_page0, PAGE_KERNEL);
+}
+
+static int __init remap_vsyscall(void)
+{
+ unsigned long physaddr_page0 = (unsigned long) &__vsyscall_0 - PAGE_OFFSET;
+
+ if (!vsyscall_mapped)
+ return 0;
+
+ /* Remap the VSYSCALL page w/ PAGE_KERNEL_VSYSCALL permissions
+ * after the alternate_instruction code has run
+ */
+ clear_fixmap(FIX_VSYSCALL_GTOD_FIRST_PAGE);
+ __set_fixmap(FIX_VSYSCALL_GTOD_FIRST_PAGE, physaddr_page0, PAGE_KERNEL_VSYSCALL);
+
+ return 0;
+}
+
+int __init vsyscall_init(void)
+{
+ printk("VSYSCALL: consistency checks...");
+ if ((unsigned long) &vgettimeofday != VSYSCALL_ADDR(__NR_vgettimeofday)) {
+ printk("vgettimeofday link addr broken\n");
+ printk("VSYSCALL: vsyscall_init failed!\n");
+ return -EFAULT;
+ }
+ if ((unsigned long) &vtime != VSYSCALL_ADDR(__NR_vtime)) {
+ printk("vtime link addr broken\n");
+ printk("VSYSCALL: vsyscall_init failed!\n");
+ return -EFAULT;
+ }
+ if (VSYSCALL_ADDR(0) != __fix_to_virt(FIX_VSYSCALL_GTOD_FIRST_PAGE)) {
+ printk("fixmap first vsyscall 0x%lx should be 0x%x\n",
+ __fix_to_virt(FIX_VSYSCALL_GTOD_FIRST_PAGE),
+ VSYSCALL_ADDR(0));
+ printk("VSYSCALL: vsyscall_init failed!\n");
+ return -EFAULT;
+ }
+
+
+ printk("passed...mapping...");
+ map_vsyscall();
+ printk("done.\n");
+ vsyscall_mapped = 1;
+ printk("VSYSCALL: fixmap virt addr: 0x%lx\n",
+ __fix_to_virt(FIX_VSYSCALL_GTOD_FIRST_PAGE));
+
+ return 0;
+}
+__initcall(remap_vsyscall);
diff -Nru a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
--- a/arch/x86_64/Kconfig 2005-04-29 15:31:09 -07:00
+++ b/arch/x86_64/Kconfig 2005-04-29 15:31:09 -07:00
@@ -57,6 +57,10 @@
bool
default y
+config NEWTOD_VSYSCALL
+ depends on EXPERIMENTAL
+ bool "VSYSCALL gettimeofday() interface"
+
config GENERIC_ISA_DMA
bool
default y
diff -Nru a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
--- a/arch/x86_64/kernel/time.c 2005-04-29 15:31:09 -07:00
+++ b/arch/x86_64/kernel/time.c 2005-04-29 15:31:09 -07:00
@@ -81,6 +81,7 @@
rdtscll(*tsc);
}
+#ifndef CONFIG_NEWTOD
/*
* do_gettimeoffset() returns microseconds since last timer interrupt was
* triggered by hardware. A memory read of HPET is slower than a register read
@@ -108,7 +109,6 @@
unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc;
-#ifndef CONFIG_NEWTOD
/*
* This version of gettimeofday() has microsecond resolution and better than
* microsecond precision, as we're using at least a 10 MHz (usually 14.31818
@@ -976,6 +976,7 @@
/* Some systems will want to disable TSC and use HPET. */
if (oem_force_hpet_timer())
notsc = 1;
+#ifndef CONFIG_NEWTOD
if (vxtime.hpet_address && notsc) {
timetype = "HPET";
vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
@@ -987,6 +988,7 @@
}
printk(KERN_INFO "time.c: Using %s based timekeeping.\n", timetype);
+#endif /* CONFIG_NEWTOD */
}
__setup("report_lost_ticks", time_setup);
diff -Nru a/arch/x86_64/kernel/vmlinux.lds.S b/arch/x86_64/kernel/vmlinux.lds.S
--- a/arch/x86_64/kernel/vmlinux.lds.S 2005-04-29 15:31:09 -07:00
+++ b/arch/x86_64/kernel/vmlinux.lds.S 2005-04-29 15:31:09 -07:00
@@ -71,6 +71,13 @@
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
.jiffies : AT CACHE_ALIGN(AFTER(.xtime)) { *(.jiffies) }
jiffies = LOADADDR(.jiffies);
+
+ .vsyscall_gtod_data : AT AFTER(.jiffies) { *(.vsyscall_gtod_data) }
+ vsyscall_gtod_data = LOADADDR(.vsyscall_gtod_data);
+ .vsyscall_gtod_lock : AT AFTER(.vsyscall_gtod_data) { *(.vsyscall_gtod_lock) }
+ vsyscall_gtod_lock = LOADADDR(.vsyscall_gtod_lock);
+
+
.vsyscall_1 ADDR(.vsyscall_0) + 1024: AT (LOADADDR(.vsyscall_0) + 1024) { *(.vsyscall_1) }
. = LOADADDR(.vsyscall_0) + 4096;
diff -Nru a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c
--- a/arch/x86_64/kernel/vsyscall.c 2005-04-29 15:31:09 -07:00
+++ b/arch/x86_64/kernel/vsyscall.c 2005-04-29 15:31:09 -07:00
@@ -19,6 +19,8 @@
* want per guest time just set the kernel.vsyscall64 sysctl to 0.
*/
+#include <linux/timeofday.h>
+#include <linux/timesource.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -40,6 +42,21 @@
int __sysctl_vsyscall __section_sysctl_vsyscall = 1;
seqlock_t __xtime_lock __section_xtime_lock = SEQLOCK_UNLOCKED;
+
+struct vsyscall_gtod_data_t {
+ struct timeval wall_time_tv;
+ struct timezone sys_tz;
+ cycle_t offset_base;
+ struct timesource_t timesource;
+};
+
+extern struct vsyscall_gtod_data_t vsyscall_gtod_data;
+struct vsyscall_gtod_data_t __vsyscall_gtod_data __section_vsyscall_gtod_data;
+
+extern seqlock_t vsyscall_gtod_lock;
+seqlock_t __vsyscall_gtod_lock __section_vsyscall_gtod_lock = SEQLOCK_UNLOCKED;
+
+
#include <asm/unistd.h>
static force_inline void timeval_normalize(struct timeval * tv)
@@ -52,7 +69,7 @@
tv->tv_sec += __sec;
}
}
-
+#ifndef CONFIG_NEWTOD_VSYSCALL
static force_inline void do_vgettimeofday(struct timeval * tv)
{
long sequence, t;
@@ -82,6 +99,52 @@
tv->tv_sec = sec + usec / 1000000;
tv->tv_usec = usec % 1000000;
}
+#else /* CONFIG_NEWTOD_VSYSCALL */
+/* XXX - this is ugly. gettimeofday() has a label in it so we can't
+ call it twice.
+ */
+static force_inline int syscall_gtod(struct timeval *tv, struct timezone *tz)
+{
+ int ret;
+ asm volatile("syscall"
+ : "=a" (ret)
+ : "0" (__NR_gettimeofday),"D" (tv),"S" (tz) : __syscall_clobber );
+ return ret;
+}
+static force_inline void do_vgettimeofday(struct timeval* tv)
+{
+ cycle_t now, cycle_delta;
+ nsec_t nsec_delta;
+ unsigned long seq;
+ do {
+ seq = read_seqbegin(&__vsyscall_gtod_lock);
+
+ if (__vsyscall_gtod_data.timesource.type == TIMESOURCE_FUNCTION) {
+ syscall_gtod(tv, NULL);
+ return;
+ }
+
+ /* read the timeosurce and calc cycle_delta */
+ now = read_timesource(&__vsyscall_gtod_data.timesource);
+ cycle_delta = (now - __vsyscall_gtod_data.offset_base)
+ & __vsyscall_gtod_data.timesource.mask;
+
+ /* convert cycles to nsecs */
+ nsec_delta = cycle_delta * __vsyscall_gtod_data.timesource.mult;
+ nsec_delta = nsec_delta >> __vsyscall_gtod_data.timesource.shift;
+
+ /* add nsec offset to wall_time_tv */
+ *tv = __vsyscall_gtod_data.wall_time_tv;
+ do_div(nsec_delta, NSEC_PER_USEC);
+ tv->tv_usec += (unsigned long) nsec_delta;
+ while (tv->tv_usec > USEC_PER_SEC) {
+ tv->tv_sec += 1;
+ tv->tv_usec -= USEC_PER_SEC;
+ }
+ } while (read_seqretry(&__vsyscall_gtod_lock, seq));
+}
+#endif /* CONFIG_NEWTOD_VSYSCALL */
+
/* RED-PEN may want to readd seq locking, but then the variable should be write-once. */
static force_inline void do_get_tz(struct timezone * tz)
@@ -139,6 +202,48 @@
return -ENOSYS;
}
+struct timesource_t* curr_timesource;
+
+void arch_update_vsyscall_gtod(nsec_t wall_time, cycle_t offset_base,
+ struct timesource_t* timesource, int ntp_adj)
+{
+ unsigned long flags;
+
+ write_seqlock_irqsave(&vsyscall_gtod_lock, flags);
+
+ /* XXX - hackitty hack hack. this is terrible! */
+ if (curr_timesource != timesource) {
+ if ((timesource->type == TIMESOURCE_MMIO_32)
+ || (timesource->type == TIMESOURCE_MMIO_64)) {
+ unsigned long vaddr = (unsigned long)timesource->mmio_ptr;
+ pgd_t *pgd = pgd_offset_k(vaddr);
+ pud_t *pud = pud_offset(pgd, vaddr);
+ pmd_t *pmd = pmd_offset(pud,vaddr);
+ pte_t *pte = pte_offset_kernel(pmd, vaddr);
+ *pte = pte_mkread(*pte);
+ }
+ curr_timesource = timesource;
+ }
+
+ /* save off wall time as timeval */
+ vsyscall_gtod_data.wall_time_tv = ns2timeval(wall_time);
+
+ /* save offset_base */
+ vsyscall_gtod_data.offset_base = offset_base;
+
+ /* copy current timesource */
+ vsyscall_gtod_data.timesource = *timesource;
+
+ /* apply ntp adjustment to timesource mult */
+ vsyscall_gtod_data.timesource.mult += ntp_adj;
+
+ /* save off current timezone */
+ vsyscall_gtod_data.sys_tz = sys_tz;
+
+ write_sequnlock_irqrestore(&vsyscall_gtod_lock, flags);
+
+}
+
#ifdef CONFIG_SYSCTL
#define SYSCALL 0x050f
@@ -217,13 +322,8 @@
BUG_ON((unsigned long) &vtime != VSYSCALL_ADDR(__NR_vtime));
BUG_ON((VSYSCALL_ADDR(0) != __fix_to_virt(VSYSCALL_FIRST_PAGE)));
map_vsyscall();
-/* XXX - disable vsyscall gettimeofday for now */
-#ifndef CONFIG_NEWTOD
sysctl_vsyscall = 1;
register_sysctl_table(kernel_root_table2, 0);
-#else
- sysctl_vsyscall = 0;
-#endif
return 0;
}
diff -Nru a/include/asm-i386/fixmap.h b/include/asm-i386/fixmap.h
--- a/include/asm-i386/fixmap.h 2005-04-29 15:31:09 -07:00
+++ b/include/asm-i386/fixmap.h 2005-04-29 15:31:09 -07:00
@@ -27,6 +27,7 @@
#include <asm/acpi.h>
#include <asm/apicdef.h>
#include <asm/page.h>
+#include <asm/vsyscall-gtod.h>
#ifdef CONFIG_HIGHMEM
#include <linux/threads.h>
#include <asm/kmap_types.h>
@@ -53,6 +54,11 @@
enum fixed_addresses {
FIX_HOLE,
FIX_VSYSCALL,
+#ifdef CONFIG_NEWTOD_VSYSCALL
+ FIX_VSYSCALL_GTOD_LAST_PAGE,
+ FIX_VSYSCALL_GTOD_FIRST_PAGE = FIX_VSYSCALL_GTOD_LAST_PAGE
+ + VSYSCALL_GTOD_NUMPAGES - 1,
+#endif
#ifdef CONFIG_X86_LOCAL_APIC
FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
#endif
diff -Nru a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h
--- a/include/asm-i386/pgtable.h 2005-04-29 15:31:09 -07:00
+++ b/include/asm-i386/pgtable.h 2005-04-29 15:31:09 -07:00
@@ -159,6 +159,8 @@
#define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL | _PAGE_PCD)
#define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE)
#define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE)
+#define __PAGE_KERNEL_VSYSCALL \
+ (_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
#define PAGE_KERNEL __pgprot(__PAGE_KERNEL)
#define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO)
@@ -166,6 +168,8 @@
#define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE)
#define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE)
#define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC)
+#define PAGE_KERNEL_VSYSCALL __pgprot(__PAGE_KERNEL_VSYSCALL)
+#define PAGE_KERNEL_VSYSCALL_NOCACHE __pgprot(__PAGE_KERNEL_VSYSCALL|(__PAGE_KERNEL_RO | _PAGE_PCD))
/*
* The i386 can't do page protection for execute, and considers that
diff -Nru a/include/asm-i386/vsyscall-gtod.h b/include/asm-i386/vsyscall-gtod.h
--- /dev/null Wed Dec 31 16:00:00 196900
+++ b/include/asm-i386/vsyscall-gtod.h 2005-04-29 15:31:09 -07:00
@@ -0,0 +1,41 @@
+#ifndef _ASM_i386_VSYSCALL_GTOD_H_
+#define _ASM_i386_VSYSCALL_GTOD_H_
+
+#ifdef CONFIG_NEWTOD_VSYSCALL
+
+/* VSYSCALL_GTOD_START must be the same as
+ * __fix_to_virt(FIX_VSYSCALL_GTOD FIRST_PAGE)
+ * and must also be same as addr in vmlinux.lds.S */
+#define VSYSCALL_GTOD_START 0xffffd000
+#define VSYSCALL_GTOD_SIZE 1024
+#define VSYSCALL_GTOD_END (VSYSCALL_GTOD_START + PAGE_SIZE)
+#define VSYSCALL_GTOD_NUMPAGES \
+ ((VSYSCALL_GTOD_END-VSYSCALL_GTOD_START) >> PAGE_SHIFT)
+#define VSYSCALL_ADDR(vsyscall_nr) \
+ (VSYSCALL_GTOD_START+VSYSCALL_GTOD_SIZE*(vsyscall_nr))
+
+#ifdef __KERNEL__
+#ifndef __ASSEMBLY__
+#include <linux/seqlock.h>
+#define __vsyscall(nr) __attribute__ ((unused,__section__(".vsyscall_" #nr)))
+
+/* ReadOnly generic time value attributes*/
+#define __section_vsyscall_gtod_data __attribute__ ((unused, __section__ (".vsyscall_gtod_data")))
+
+#define __section_vsyscall_gtod_lock __attribute__ ((unused, __section__ (".vsyscall_gtod_lock")))
+
+
+enum vsyscall_num {
+ __NR_vgettimeofday,
+ __NR_vtime,
+};
+
+int vsyscall_init(void);
+extern char __vsyscall_0;
+#endif /* __ASSEMBLY__ */
+#endif /* __KERNEL__ */
+#else /* CONFIG_NEWTOD_VSYSCALL */
+#define vsyscall_init()
+#define vsyscall_set_timesource(x)
+#endif /* CONFIG_NEWTOD_VSYSCALL */
+#endif /* _ASM_i386_VSYSCALL_GTOD_H_ */
diff -Nru a/include/asm-x86_64/vsyscall.h b/include/asm-x86_64/vsyscall.h
--- a/include/asm-x86_64/vsyscall.h 2005-04-29 15:31:09 -07:00
+++ b/include/asm-x86_64/vsyscall.h 2005-04-29 15:31:09 -07:00
@@ -22,6 +22,8 @@
#define __section_sysctl_vsyscall __attribute__ ((unused, __section__ (".sysctl_vsyscall"), aligned(16)))
#define __section_xtime __attribute__ ((unused, __section__ (".xtime"), aligned(16)))
#define __section_xtime_lock __attribute__ ((unused, __section__ (".xtime_lock"), aligned(16)))
+#define __section_vsyscall_gtod_data __attribute__ ((unused, __section__ (".vsyscall_gtod_data"),aligned(16)))
+#define __section_vsyscall_gtod_lock __attribute__ ((unused, __section__ (".vsyscall_gtod_lock"),aligned(16)))
#define VXTIME_TSC 1
#define VXTIME_HPET 2
diff -Nru a/kernel/timeofday.c b/kernel/timeofday.c
--- a/kernel/timeofday.c 2005-04-29 15:31:09 -07:00
+++ b/kernel/timeofday.c 2005-04-29 15:31:09 -07:00
@@ -41,7 +41,6 @@
* o Added getnstimeofday
* o Cleanups from Nish Aravamudan
* TODO List:
-* o vsyscall/fsyscall infrastructure
* o clock_was_set hook
**********************************************************************/
@@ -116,6 +115,12 @@
*/
extern nsec_t read_persistent_clock(void);
extern void sync_persistent_clock(struct timespec ts);
+#ifdef CONFIG_NEWTOD_VSYSCALL
+extern void arch_update_vsyscall_gtod(nsec_t wall_time, cycle_t offset_base,
+ struct timesource_t* timesource, int ntp_adj);
+#else
+#define arch_update_vsyscall_gtod(x,y,z,w) {}
+#endif
/* get_lowres_timestamp():
@@ -282,6 +287,9 @@
update_legacy_time_values();
+ arch_update_vsyscall_gtod(system_time + wall_time_offset, offset_base,
+ timesource, ntp_adj);
+
write_sequnlock_irqrestore(&system_time_lock, flags);
return 0;
@@ -473,6 +481,9 @@
/* sync legacy values */
update_legacy_time_values();
+ arch_update_vsyscall_gtod(system_time + wall_time_offset, offset_base,
+ timesource, ntp_adj);
+
write_sequnlock_irqrestore(&system_time_lock, flags);
/* Set us up to go off on the next interval */
@@ -501,6 +512,9 @@
/* clear NTP scaling factor & state machine */
ntp_adj = 0;
ntp_clear();
+
+ arch_update_vsyscall_gtod(system_time + wall_time_offset, offset_base,
+ timesource, ntp_adj);
/* initialize legacy time values */
update_legacy_time_values();
-
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