Mailing List Archive

commit 06c81ea90c18c71725f51dfff79d4c4396b53d6c
Author: Jan Beulich <jbeulich@suse.com>
AuthorDate: Wed Jan 17 10:43:02 2024 +0100
Commit: Andrew Cooper <andrew.cooper3@citrix.com>
CommitDate: Tue Apr 9 16:48:18 2024 +0100

x86/HPET: avoid an indirect call

When this code was written, indirect branches still weren't considered
much of a problem (besides being a little slower). Instead of a function
pointer, pass a boolean to _disable_pit_irq(), thus allowing to
eliminate two ENDBR (one of them in .text).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 730d2637a8e5b98dc8e4e366179b4cedc496b3ad)
---
xen/arch/x86/hpet.c | 4 ++--
xen/arch/x86/include/asm/hpet.h | 4 ++--
xen/arch/x86/time.c | 12 ++++++------
3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/xen/arch/x86/hpet.c b/xen/arch/x86/hpet.c
index bc164dd82c..50d788cb6e 100644
--- a/xen/arch/x86/hpet.c
+++ b/xen/arch/x86/hpet.c
@@ -563,7 +563,7 @@ static void cf_check handle_rtc_once(uint8_t index, uint8_t value)
}
}

-void __init cf_check hpet_broadcast_init(void)
+void __init hpet_broadcast_init(void)
{
u64 hpet_rate = hpet_setup();
u32 hpet_id, cfg;
@@ -634,7 +634,7 @@ void __init cf_check hpet_broadcast_init(void)
hpet_events->flags = HPET_EVT_LEGACY;
}

-void cf_check hpet_broadcast_resume(void)
+void hpet_broadcast_resume(void)
{
u32 cfg;
unsigned int i, n;
diff --git a/xen/arch/x86/include/asm/hpet.h b/xen/arch/x86/include/asm/hpet.h
index 9919f74730..f343fe4740 100644
--- a/xen/arch/x86/include/asm/hpet.h
+++ b/xen/arch/x86/include/asm/hpet.h
@@ -89,8 +89,8 @@ void hpet_disable_legacy_replacement_mode(void);
* Temporarily use an HPET event counter for timer interrupt handling,
* rather than using the LAPIC timer. Used for Cx state entry.
*/
-void cf_check hpet_broadcast_init(void);
-void cf_check hpet_broadcast_resume(void);
+void hpet_broadcast_init(void);
+void hpet_broadcast_resume(void);
void cf_check hpet_broadcast_enter(void);
void cf_check hpet_broadcast_exit(void);
int hpet_broadcast_is_available(void);
diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index b664ae4c83..4d1766284f 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -2288,7 +2288,7 @@ void __init early_time_init(void)
}

/* keep pit enabled for pit_broadcast working while cpuidle enabled */
-static int _disable_pit_irq(void(*hpet_broadcast_setup)(void))
+static int _disable_pit_irq(bool init)
{
int ret = 1;

@@ -2303,13 +2303,13 @@ static int _disable_pit_irq(void(*hpet_broadcast_setup)(void))
*/
if ( cpuidle_using_deep_cstate() && !boot_cpu_has(X86_FEATURE_ARAT) )
{
- hpet_broadcast_setup();
+ init ? hpet_broadcast_init() : hpet_broadcast_resume();
if ( !hpet_broadcast_is_available() )
{
if ( xen_cpuidle > 0 )
{
- printk("%ps() failed, turning to PIT broadcast\n",
- hpet_broadcast_setup);
+ printk("hpet_broadcast_%s() failed, turning to PIT broadcast\n",
+ init ? "init" : "resume");
return -1;
}
ret = 0;
@@ -2326,7 +2326,7 @@ static int _disable_pit_irq(void(*hpet_broadcast_setup)(void))

static int __init cf_check disable_pit_irq(void)
{
- if ( !_disable_pit_irq(hpet_broadcast_init) )
+ if ( !_disable_pit_irq(true) )
{
xen_cpuidle = 0;
printk("CPUIDLE: disabled due to no HPET. "
@@ -2387,7 +2387,7 @@ int time_resume(void)

resume_platform_timer();

- if ( !_disable_pit_irq(hpet_broadcast_resume) )
+ if ( !_disable_pit_irq(false) )
BUG();

init_percpu_time();
--
generated by git-patchbot for /home/xen/git/xen.git#staging-4.17