[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel

This patch moves the vdso's to arch/powerpc, adds support for the 32
bits vdso to the 32 bits kernel, rename systemcfg (finally !), and adds
some new (still untested) routines to both vdso's: clock_gettime() with
support for CLOCK_REALTIME and CLOCK_MONOTONIC, clock_getres() (same
clocks) and get_tbfreq() for glibc to retreive the timebase frequency.

Tom,Steve: The implementation of get_tbfreq() I've done for 32 bits
returns a long long (r3, r4) not a long. This is such that if we ever
add support for >4Ghz timebases on ppc32, the userland interface won't
have to change.

I have tested gettimeofday() using some glibc patches in both ppc32 and
ppc64 kernels using 32 bits userland (I haven't had a chance to test a
64 bits userland yet, but the implementation didn't change and was
tested earlier). I haven't tested yet the new functions.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 260b6ec..070b4b4 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -62,8 +62,8 @@
 #include <asm/irq.h>
 #include <asm/div64.h>
 #include <asm/smp.h>
+#include <asm/vdso_datapage.h>
 #ifdef CONFIG_PPC64
-#include <asm/systemcfg.h>
 #include <asm/firmware.h>
 #endif
 #ifdef CONFIG_PPC_ISERIES
@@ -261,7 +261,6 @@
 	do_gtod.varp = temp_varp;
 	do_gtod.var_idx = temp_idx;
 
-#ifdef CONFIG_PPC64
 	/*
 	 * tb_update_count is used to allow the userspace gettimeofday code
 	 * to assure itself that it sees a consistent view of the tb_to_xs and
@@ -271,14 +270,15 @@
 	 * tb_to_xs and stamp_xsec values are consistent.  If not, then it
 	 * loops back and reads them again until this criteria is met.
 	 */
-	++(_systemcfg->tb_update_count);
+	++(vdso_data->tb_update_count);
 	smp_wmb();
-	_systemcfg->tb_orig_stamp = new_tb_stamp;
-	_systemcfg->stamp_xsec = new_stamp_xsec;
-	_systemcfg->tb_to_xs = new_tb_to_xs;
+	vdso_data->tb_orig_stamp = new_tb_stamp;
+	vdso_data->stamp_xsec = new_stamp_xsec;
+	vdso_data->tb_to_xs = new_tb_to_xs;
+	vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec;
+	vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec;
 	smp_wmb();
-	++(_systemcfg->tb_update_count);
-#endif
+	++(vdso_data->tb_update_count);
 }
 
 /*
@@ -357,9 +357,8 @@
 				do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
 				tb_to_xs = divres.result_low;
 				do_gtod.varp->tb_to_xs = tb_to_xs;
-				_systemcfg->tb_ticks_per_sec =
-					tb_ticks_per_sec;
-				_systemcfg->tb_to_xs = tb_to_xs;
+				vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
+				vdso_data->tb_to_xs = tb_to_xs;
 			}
 			else {
 				printk( "Titan recalibrate: FAILED (difference > 4 percent)\n"
@@ -561,10 +560,8 @@
 	new_xsec += (u64)new_sec * XSEC_PER_SEC - tb_delta_xs;
 	update_gtod(tb_last_jiffy, new_xsec, do_gtod.varp->tb_to_xs);
 
-#ifdef CONFIG_PPC64
-	_systemcfg->tz_minuteswest = sys_tz.tz_minuteswest;
-	_systemcfg->tz_dsttime = sys_tz.tz_dsttime;
-#endif
+	vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
+	vdso_data->tz_dsttime = sys_tz.tz_dsttime;
 
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 	clock_was_set();
@@ -713,13 +710,12 @@
 	do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
 	do_gtod.varp->tb_to_xs = tb_to_xs;
 	do_gtod.tb_to_us = tb_to_us;
-#ifdef CONFIG_PPC64
-	_systemcfg->tb_orig_stamp = tb_last_jiffy;
-	_systemcfg->tb_update_count = 0;
-	_systemcfg->tb_ticks_per_sec = tb_ticks_per_sec;
-	_systemcfg->stamp_xsec = xtime.tv_sec * XSEC_PER_SEC;
-	_systemcfg->tb_to_xs = tb_to_xs;
-#endif
+
+	vdso_data->tb_orig_stamp = tb_last_jiffy;
+	vdso_data->tb_update_count = 0;
+	vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
+	vdso_data->stamp_xsec = xtime.tv_sec * XSEC_PER_SEC;
+	vdso_data->tb_to_xs = tb_to_xs;
 
 	time_freq = 0;