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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-12 05:01:33 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-12 05:01:33 +0100
commit1ebaf4f4e6912199f8a4e30ba3ab55da2b71bcdf (patch)
treed2073d669e6eaf15ece6fc6ce563438d74824412
parentMerge branch 'x86-nuke386-for-linus' of git://git.kernel.org/pub/scm/linux/ke... (diff)
parentx86: hpet: Fix inverted return value check in arch_setup_hpet_msi() (diff)
downloadlinux-1ebaf4f4e6912199f8a4e30ba3ab55da2b71bcdf.tar.xz
linux-1ebaf4f4e6912199f8a4e30ba3ab55da2b71bcdf.zip
Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 timer update from Ingo Molnar: "This tree includes HPET fixes and also implements a calibration-free, TSC match driven APIC timer interrupt mode: 'TSC deadline mode' supported in SandyBridge and later CPUs." * 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: hpet: Fix inverted return value check in arch_setup_hpet_msi() x86: hpet: Fix masking of MSI interrupts x86: apic: Use tsc deadline for oneshot when available
-rw-r--r--Documentation/kernel-parameters.txt4
-rw-r--r--arch/x86/include/asm/msr-index.h2
-rw-r--r--arch/x86/kernel/apic/apic.c73
-rw-r--r--arch/x86/kernel/apic/io_apic.c5
-rw-r--r--arch/x86/kernel/hpet.c4
5 files changed, 64 insertions, 24 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 5190f1706414..28bd0f0e32c5 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1304,6 +1304,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
lapic [X86-32,APIC] Enable the local APIC even if BIOS
disabled it.
+ lapic= [x86,APIC] "notscdeadline" Do not use TSC deadline
+ value for LAPIC timer one-shot implementation. Default
+ back to the programmable timer unit in the LAPIC.
+
lapic_timer_c2_ok [X86,APIC] trust the local apic timer
in C2 power state.
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 7f0edceb7563..e400cdb2dd65 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -337,6 +337,8 @@
#define MSR_IA32_MISC_ENABLE_TURBO_DISABLE (1ULL << 38)
#define MSR_IA32_MISC_ENABLE_IP_PREF_DISABLE (1ULL << 39)
+#define MSR_IA32_TSC_DEADLINE 0x000006E0
+
/* P4/Xeon+ specific */
#define MSR_IA32_MCG_EAX 0x00000180
#define MSR_IA32_MCG_EBX 0x00000181
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index b17416e72fbd..b994cc84aa7e 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -90,21 +90,6 @@ EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
*/
DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);
-/*
- * Knob to control our willingness to enable the local APIC.
- *
- * +1=force-enable
- */
-static int force_enable_local_apic __initdata;
-/*
- * APIC command line parameters
- */
-static int __init parse_lapic(char *arg)
-{
- force_enable_local_apic = 1;
- return 0;
-}
-early_param("lapic", parse_lapic);
/* Local APIC was disabled by the BIOS and enabled by the kernel */
static int enabled_via_apicbase;
@@ -133,6 +118,25 @@ static inline void imcr_apic_to_pic(void)
}
#endif
+/*
+ * Knob to control our willingness to enable the local APIC.
+ *
+ * +1=force-enable
+ */
+static int force_enable_local_apic __initdata;
+/*
+ * APIC command line parameters
+ */
+static int __init parse_lapic(char *arg)
+{
+ if (config_enabled(CONFIG_X86_32) && !arg)
+ force_enable_local_apic = 1;
+ else if (!strncmp(arg, "notscdeadline", 13))
+ setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
+ return 0;
+}
+early_param("lapic", parse_lapic);
+
#ifdef CONFIG_X86_64
static int apic_calibrate_pmtmr __initdata;
static __init int setup_apicpmtimer(char *s)
@@ -315,6 +319,7 @@ int lapic_get_maxlvt(void)
/* Clock divisor */
#define APIC_DIVISOR 16
+#define TSC_DIVISOR 32
/*
* This function sets up the local APIC timer, with a timeout of
@@ -333,6 +338,9 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
lvtt_value = LOCAL_TIMER_VECTOR;
if (!oneshot)
lvtt_value |= APIC_LVT_TIMER_PERIODIC;
+ else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
+ lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
+
if (!lapic_is_integrated())
lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
@@ -341,6 +349,11 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
apic_write(APIC_LVTT, lvtt_value);
+ if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
+ printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
+ return;
+ }
+
/*
* Divide PICLK by 16
*/
@@ -453,6 +466,16 @@ static int lapic_next_event(unsigned long delta,
return 0;
}
+static int lapic_next_deadline(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ u64 tsc;
+
+ rdtscll(tsc);
+ wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
+ return 0;
+}
+
/*
* Setup the lapic timer in periodic or oneshot mode
*/
@@ -533,7 +556,15 @@ static void __cpuinit setup_APIC_timer(void)
memcpy(levt, &lapic_clockevent, sizeof(*levt));
levt->cpumask = cpumask_of(smp_processor_id());
- clockevents_register_device(levt);
+ if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
+ levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
+ CLOCK_EVT_FEAT_DUMMY);
+ levt->set_next_event = lapic_next_deadline;
+ clockevents_config_and_register(levt,
+ (tsc_khz / TSC_DIVISOR) * 1000,
+ 0xF, ~0UL);
+ } else
+ clockevents_register_device(levt);
}
/*
@@ -661,7 +692,9 @@ static int __init calibrate_APIC_clock(void)
* in the clockevent structure and return.
*/
- if (lapic_timer_frequency) {
+ if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
+ return 0;
+ } else if (lapic_timer_frequency) {
apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
lapic_timer_frequency);
lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
@@ -674,6 +707,9 @@ static int __init calibrate_APIC_clock(void)
return 0;
}
+ apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
+ "calibrating APIC timer ...\n");
+
local_irq_disable();
/* Replace the global interrupt handler */
@@ -811,9 +847,6 @@ void __init setup_boot_APIC_clock(void)
return;
}
- apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
- "calibrating APIC timer ...\n");
-
if (calibrate_APIC_clock()) {
/* No broadcast on UP ! */
if (num_possible_cpus() > 1)
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 70aa621df118..b739d398bb29 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3305,8 +3305,9 @@ int arch_setup_hpet_msi(unsigned int irq, unsigned int id)
int ret;
if (irq_remapping_enabled) {
- if (!setup_hpet_msi_remapped(irq, id))
- return -1;
+ ret = setup_hpet_msi_remapped(irq, id);
+ if (ret)
+ return ret;
}
ret = msi_compose_msg(NULL, irq, &msg, id);
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 1460a5df92f7..e28670f9a589 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -434,7 +434,7 @@ void hpet_msi_unmask(struct irq_data *data)
/* unmask it */
cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
- cfg |= HPET_TN_FSB;
+ cfg |= HPET_TN_ENABLE | HPET_TN_FSB;
hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
}
@@ -445,7 +445,7 @@ void hpet_msi_mask(struct irq_data *data)
/* mask it */
cfg = hpet_readl(HPET_Tn_CFG(hdev->num));
- cfg &= ~HPET_TN_FSB;
+ cfg &= ~(HPET_TN_ENABLE | HPET_TN_FSB);
hpet_writel(cfg, HPET_Tn_CFG(hdev->num));
}