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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-11 19:13:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-11 19:13:40 -0800
commit9fc5c3e3237e02a94f41cd1d2b4291593d29791d (patch)
treec8823725b10bd4d36e9311ea392dfdecb4db7974 /arch/x86/kernel
parent541048a1d31399ccdda27346a37eae4a2ad55186 (diff)
parent7c9c3a1e5fc8728e948b8fa3cbcfcfb86db3afda (diff)
Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/intel config: Fix the APB_TIMER selection x86/mrst: Add additional debug prints for pb_keys x86/intel config: Revamp configuration to allow for Moorestown and Medfield x86/intel/scu/ipc: Match the changes in the x86 configuration x86/apb: Fix configuration constraints x86: Fix INTEL_MID silly x86/Kconfig: Cyclone-timer depends on x86-summit x86: Reduce clock calibration time during slave cpu startup x86/config: Revamp configuration for MID devices x86/sfi: Kill the IRQ as id hack
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/early_printk.c2
-rw-r--r--arch/x86/kernel/smpboot.c16
-rw-r--r--arch/x86/kernel/tsc.c20
3 files changed, 32 insertions, 6 deletions
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 9d42a52d233..9b9f18b4991 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -240,7 +240,7 @@ static int __init setup_early_printk(char *buf)
if (!strncmp(buf, "xen", 3))
early_console_register(&xenboot_console, keep);
#endif
-#ifdef CONFIG_EARLY_PRINTK_MRST
+#ifdef CONFIG_EARLY_PRINTK_INTEL_MID
if (!strncmp(buf, "mrst", 4)) {
mrst_early_console_init();
early_console_register(&early_mrst_console, keep);
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 79f636bc44c..66d250c00d1 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -207,23 +207,29 @@ static void __cpuinit smp_callin(void)
* Need to setup vector mappings before we enable interrupts.
*/
setup_vector_irq(smp_processor_id());
+
+ /*
+ * Save our processor parameters. Note: this information
+ * is needed for clock calibration.
+ */
+ smp_store_cpu_info(cpuid);
+
/*
* Get our bogomips.
+ * Update loops_per_jiffy in cpu_data. Previous call to
+ * smp_store_cpu_info() stored a value that is close but not as
+ * accurate as the value just calculated.
*
* Need to enable IRQs because it can take longer and then
* the NMI watchdog might kill us.
*/
local_irq_enable();
calibrate_delay();
+ cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy;
local_irq_disable();
pr_debug("Stack at about %p\n", &cpuid);
/*
- * Save our processor parameters
- */
- smp_store_cpu_info(cpuid);
-
- /*
* This must be done before setting cpu_online_mask
* or calling notify_cpu_starting.
*/
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 2c9cf0fd78f..c0dd5b60374 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -995,3 +995,23 @@ void __init tsc_init(void)
check_system_tsc_reliable();
}
+#ifdef CONFIG_SMP
+/*
+ * If we have a constant TSC and are using the TSC for the delay loop,
+ * we can skip clock calibration if another cpu in the same socket has already
+ * been calibrated. This assumes that CONSTANT_TSC applies to all
+ * cpus in the socket - this should be a safe assumption.
+ */
+unsigned long __cpuinit calibrate_delay_is_known(void)
+{
+ int i, cpu = smp_processor_id();
+
+ if (!tsc_disabled && !cpu_has(&cpu_data(cpu), X86_FEATURE_CONSTANT_TSC))
+ return 0;
+
+ for_each_online_cpu(i)
+ if (cpu_data(i).phys_proc_id == cpu_data(cpu).phys_proc_id)
+ return cpu_data(i).loops_per_jiffy;
+ return 0;
+}
+#endif