From: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Add rudimentary TSC-based clocksource support (based on Rusty's original
patch). Needs to be enhanced for frequency scaling.
Signed-off-by: James Morris <jmorris@xxxxxxxxx>
---
arch/i386/kernel/tsc.c | 1 +
drivers/lguest/hypercalls.c | 6 +++++-
drivers/lguest/lguest.c | 25 +++++++++++++++++++++++++
include/linux/lguest.h | 2 ++
4 files changed, 33 insertions(+), 1 deletions(-)
diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c
index 7a5091d..3c82af5 100644
--- a/arch/i386/kernel/tsc.c
+++ b/arch/i386/kernel/tsc.c
@@ -26,6 +26,7 @@ static int tsc_enabled;
* an extra value to store the TSC freq
*/
unsigned int tsc_khz;
+EXPORT_SYMBOL_GPL(tsc_khz);
int tsc_disable;
diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index 0eec0fe..a8c0b86 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -23,6 +23,7 @@
#include <linux/uaccess.h>
#include <linux/syscalls.h>
#include <linux/mm.h>
+#include <linux/clocksource.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <irq_vectors.h>
@@ -222,7 +223,10 @@ static void initialize(struct lguest *lg)
if (get_user(lg->noirq_start, &lg->lguest_data->noirq_start)
|| get_user(lg->noirq_end, &lg->lguest_data->noirq_end)
/* We also give the Guest a unique id, as used in lguest_net.c. */
- || put_user(lg->guestid, &lg->lguest_data->guestid))
+ || put_user(lg->guestid, &lg->lguest_data->guestid)
+ /* TSC clock multiplier is determined at runtime */
+ || put_user(clocksource_khz2mult(tsc_khz, 22),
+ &lg->lguest_data->clock_mult))
kill_guest(lg, "bad guest page %p", lg->lguest_data);
/* page_tables.c will also do some setup. */
diff --git a/drivers/lguest/lguest.c b/drivers/lguest/lguest.c
index f4f300f..e102c35 100644
--- a/drivers/lguest/lguest.c
+++ b/drivers/lguest/lguest.c
@@ -52,6 +52,7 @@
#include <linux/screen_info.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
+#include <linux/clocksource.h>
#include <linux/lguest.h>
#include <linux/lguest_launcher.h>
#include <asm/paravirt.h>
@@ -618,6 +619,29 @@ static void lguest_time_irq(unsigned int irq, struct irq_desc *desc)
update_process_times(user_mode_vm(get_irq_regs()));
}
+static cycle_t lguest_clock_read(void)
+{
+ /* FIXME: This is just the native one. Account stolen time! */
+ return paravirt_ops.read_tsc();
+}
+
+/* FIXME: Update iff tsc rate changes. */
+static struct clocksource lguest_clock = {
+ .name = "lguest",
+ .rating = 400,
+ .read = lguest_clock_read,
+ .mask = CLOCKSOURCE_MASK(64),
+ .mult = 0, /* to be set */
+ .shift = 22,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void lguest_setup_clocksource(void)
+{
+ lguest_clock.mult = lguest_data.clock_mult;
+ clocksource_register(&lguest_clock);
+}
+
/* At some point in the boot process, we get asked to set up our timing
* infrastructure. The kernel doesn't expect timer interrupts before this, but
* we cleverly initialized the "blocked_interrupts" field of "struct
@@ -627,6 +651,7 @@ static void lguest_time_init(void)
/* We set up the timer interrupt (0) to go to our simple timer
* routine */
set_irq_handler(0, lguest_time_irq);
+ lguest_setup_clocksource();
/* Ask the Host for the time once. Since the TIMER_READ hypercall
* returns the number of ticks since it was last called, this means it
* will return the right thing when we call it next time, from
diff --git a/include/linux/lguest.h b/include/linux/lguest.h
index f41392c..6ce0865 100644
--- a/include/linux/lguest.h
+++ b/include/linux/lguest.h
@@ -99,6 +99,8 @@ struct lguest_data
unsigned long reserve_mem;
/* ID of this Guest (used by network driver to set ethernet address) */
u16 guestid;
+ /* Multiplier for TSC clock. */
+ u32 clock_mult;
/* Page where the top-level pagetable is */
unsigned long pgdir;
--
1.5.0.6
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