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Diffstat (limited to 'arch/i386/kernel/smpboot.c')
-rw-r--r--arch/i386/kernel/smpboot.c203
1 files changed, 28 insertions, 175 deletions
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index 8c6c8c52b95c..48bfcaa13ecc 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -63,6 +63,7 @@
#include <mach_apic.h>
#include <mach_wakecpu.h>
#include <smpboot_hooks.h>
+#include <asm/vmi.h>
/* Set if we find a B stepping CPU */
static int __devinitdata smp_b_stepping;
@@ -93,12 +94,6 @@ cpumask_t cpu_possible_map;
EXPORT_SYMBOL(cpu_possible_map);
static cpumask_t smp_commenced_mask;
-/* TSC's upper 32 bits can't be written in eariler CPU (before prescott), there
- * is no way to resync one AP against BP. TBD: for prescott and above, we
- * should use IA64's algorithm
- */
-static int __devinitdata tsc_sync_disabled;
-
/* Per CPU bogomips and other parameters */
struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
EXPORT_SYMBOL(cpu_data);
@@ -215,151 +210,6 @@ valid_k7:
;
}
-/*
- * TSC synchronization.
- *
- * We first check whether all CPUs have their TSC's synchronized,
- * then we print a warning if not, and always resync.
- */
-
-static struct {
- atomic_t start_flag;
- atomic_t count_start;
- atomic_t count_stop;
- unsigned long long values[NR_CPUS];
-} tsc __cpuinitdata = {
- .start_flag = ATOMIC_INIT(0),
- .count_start = ATOMIC_INIT(0),
- .count_stop = ATOMIC_INIT(0),
-};
-
-#define NR_LOOPS 5
-
-static void __init synchronize_tsc_bp(void)
-{
- int i;
- unsigned long long t0;
- unsigned long long sum, avg;
- long long delta;
- unsigned int one_usec;
- int buggy = 0;
-
- printk(KERN_INFO "checking TSC synchronization across %u CPUs: ", num_booting_cpus());
-
- /* convert from kcyc/sec to cyc/usec */
- one_usec = cpu_khz / 1000;
-
- atomic_set(&tsc.start_flag, 1);
- wmb();
-
- /*
- * We loop a few times to get a primed instruction cache,
- * then the last pass is more or less synchronized and
- * the BP and APs set their cycle counters to zero all at
- * once. This reduces the chance of having random offsets
- * between the processors, and guarantees that the maximum
- * delay between the cycle counters is never bigger than
- * the latency of information-passing (cachelines) between
- * two CPUs.
- */
- for (i = 0; i < NR_LOOPS; i++) {
- /*
- * all APs synchronize but they loop on '== num_cpus'
- */
- while (atomic_read(&tsc.count_start) != num_booting_cpus()-1)
- cpu_relax();
- atomic_set(&tsc.count_stop, 0);
- wmb();
- /*
- * this lets the APs save their current TSC:
- */
- atomic_inc(&tsc.count_start);
-
- rdtscll(tsc.values[smp_processor_id()]);
- /*
- * We clear the TSC in the last loop:
- */
- if (i == NR_LOOPS-1)
- write_tsc(0, 0);
-
- /*
- * Wait for all APs to leave the synchronization point:
- */
- while (atomic_read(&tsc.count_stop) != num_booting_cpus()-1)
- cpu_relax();
- atomic_set(&tsc.count_start, 0);
- wmb();
- atomic_inc(&tsc.count_stop);
- }
-
- sum = 0;
- for (i = 0; i < NR_CPUS; i++) {
- if (cpu_isset(i, cpu_callout_map)) {
- t0 = tsc.values[i];
- sum += t0;
- }
- }
- avg = sum;
- do_div(avg, num_booting_cpus());
-
- for (i = 0; i < NR_CPUS; i++) {
- if (!cpu_isset(i, cpu_callout_map))
- continue;
- delta = tsc.values[i] - avg;
- if (delta < 0)
- delta = -delta;
- /*
- * We report bigger than 2 microseconds clock differences.
- */
- if (delta > 2*one_usec) {
- long long realdelta;
-
- if (!buggy) {
- buggy = 1;
- printk("\n");
- }
- realdelta = delta;
- do_div(realdelta, one_usec);
- if (tsc.values[i] < avg)
- realdelta = -realdelta;
-
- if (realdelta)
- printk(KERN_INFO "CPU#%d had %Ld usecs TSC "
- "skew, fixed it up.\n", i, realdelta);
- }
- }
- if (!buggy)
- printk("passed.\n");
-}
-
-static void __cpuinit synchronize_tsc_ap(void)
-{
- int i;
-
- /*
- * Not every cpu is online at the time
- * this gets called, so we first wait for the BP to
- * finish SMP initialization:
- */
- while (!atomic_read(&tsc.start_flag))
- cpu_relax();
-
- for (i = 0; i < NR_LOOPS; i++) {
- atomic_inc(&tsc.count_start);
- while (atomic_read(&tsc.count_start) != num_booting_cpus())
- cpu_relax();
-
- rdtscll(tsc.values[smp_processor_id()]);
- if (i == NR_LOOPS-1)
- write_tsc(0, 0);
-
- atomic_inc(&tsc.count_stop);
- while (atomic_read(&tsc.count_stop) != num_booting_cpus())
- cpu_relax();
- }
-}
-#undef NR_LOOPS
-
extern void calibrate_delay(void);
static atomic_t init_deasserted;
@@ -437,20 +287,12 @@ static void __cpuinit smp_callin(void)
/*
* Save our processor parameters
*/
- smp_store_cpu_info(cpuid);
-
- disable_APIC_timer();
+ smp_store_cpu_info(cpuid);
/*
* Allow the master to continue.
*/
cpu_set(cpuid, cpu_callin_map);
-
- /*
- * Synchronize the TSC with the BP
- */
- if (cpu_has_tsc && cpu_khz && !tsc_sync_disabled)
- synchronize_tsc_ap();
}
static int cpucount;
@@ -545,18 +387,25 @@ static void __cpuinit start_secondary(void *unused)
* booting is too fragile that we want to limit the
* things done here to the most necessary things.
*/
+#ifdef CONFIG_VMI
+ vmi_bringup();
+#endif
secondary_cpu_init();
preempt_disable();
smp_callin();
while (!cpu_isset(smp_processor_id(), smp_commenced_mask))
rep_nop();
- setup_secondary_APIC_clock();
+ /*
+ * Check TSC synchronization with the BP:
+ */
+ check_tsc_sync_target();
+
+ setup_secondary_clock();
if (nmi_watchdog == NMI_IO_APIC) {
disable_8259A_irq(0);
enable_NMI_through_LVT0(NULL);
enable_8259A_irq(0);
}
- enable_APIC_timer();
/*
* low-memory mappings have been cleared, flush them from
* the local TLBs too.
@@ -619,7 +468,6 @@ extern struct {
unsigned short ss;
} stack_start;
extern struct i386_pda *start_pda;
-extern struct Xgt_desc_struct cpu_gdt_descr;
#ifdef CONFIG_NUMA
@@ -749,7 +597,7 @@ wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
/*
* Due to the Pentium erratum 3AP.
*/
- maxlvt = get_maxlvt();
+ maxlvt = lapic_get_maxlvt();
if (maxlvt > 3) {
apic_read_around(APIC_SPIV);
apic_write(APIC_ESR, 0);
@@ -835,11 +683,18 @@ wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
num_starts = 0;
/*
+ * Paravirt / VMI wants a startup IPI hook here to set up the
+ * target processor state.
+ */
+ startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
+ (unsigned long) stack_start.esp);
+
+ /*
* Run STARTUP IPI loop.
*/
Dprintk("#startup loops: %d.\n", num_starts);
- maxlvt = get_maxlvt();
+ maxlvt = lapic_get_maxlvt();
for (j = 1; j <= num_starts; j++) {
Dprintk("Sending STARTUP #%d.\n",j);
@@ -1115,8 +970,6 @@ static int __cpuinit __smp_prepare_cpu(int cpu)
info.cpu = cpu;
INIT_WORK(&info.task, do_warm_boot_cpu);
- tsc_sync_disabled = 1;
-
/* init low mem mapping */
clone_pgd_range(swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
min_t(unsigned long, KERNEL_PGD_PTRS, USER_PGD_PTRS));
@@ -1124,7 +977,6 @@ static int __cpuinit __smp_prepare_cpu(int cpu)
schedule_work(&info.task);
wait_for_completion(&done);
- tsc_sync_disabled = 0;
zap_low_mappings();
ret = 0;
exit:
@@ -1320,13 +1172,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
smpboot_setup_io_apic();
- setup_boot_APIC_clock();
-
- /*
- * Synchronize the TSC with the AP
- */
- if (cpu_has_tsc && cpucount && cpu_khz)
- synchronize_tsc_bp();
+ setup_boot_clock();
}
/* These are wrappers to interface to the new boot process. Someone
@@ -1461,9 +1307,16 @@ int __cpuinit __cpu_up(unsigned int cpu)
}
local_irq_enable();
+
per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
/* Unleash the CPU! */
cpu_set(cpu, smp_commenced_mask);
+
+ /*
+ * Check TSC synchronization with the AP:
+ */
+ check_tsc_sync_source(cpu);
+
while (!cpu_isset(cpu, cpu_online_map))
cpu_relax();