doc/share/security/patches/EN-16:07/ipi.patch
Gleb Smirnoff cf13b85a51 Publish todays advisory and notices:
- SA-16:17.openssl
- EN-16:06.libc
- EN-16:07.ipi
- EN-16:08.zfs

Approved by:	so
2016-05-04 22:52:54 +00:00

103 lines
2.5 KiB
Diff

--- sys/x86/x86/local_apic.c.orig
+++ sys/x86/x86/local_apic.c
@@ -56,6 +56,7 @@
#include <vm/pmap.h>
#include <x86/apicreg.h>
+#include <machine/clock.h>
#include <machine/cputypes.h>
#include <machine/frame.h>
#include <machine/intr_machdep.h>
@@ -158,6 +159,9 @@
vm_paddr_t lapic_paddr;
static u_long lapic_timer_divisor;
static struct eventtimer lapic_et;
+#ifdef SMP
+static uint64_t lapic_ipi_wait_mult;
+#endif
static void lapic_enable(void);
static void lapic_resume(struct pic *pic, bool suspend_cancelled);
@@ -221,6 +225,9 @@
void
lapic_init(vm_paddr_t addr)
{
+#ifdef SMP
+ uint64_t r, r1, r2, rx;
+#endif
u_int regs[4];
int i, arat;
@@ -275,6 +282,38 @@
lapic_et.et_priv = NULL;
et_register(&lapic_et);
}
+
+#ifdef SMP
+#define LOOPS 1000000
+ /*
+ * Calibrate the busy loop waiting for IPI ack in xAPIC mode.
+ * lapic_ipi_wait_mult contains the number of iterations which
+ * approximately delay execution for 1 microsecond (the
+ * argument to native_lapic_ipi_wait() is in microseconds).
+ *
+ * We assume that TSC is present and already measured.
+ * Possible TSC frequency jumps are irrelevant to the
+ * calibration loop below, the CPU clock management code is
+ * not yet started, and we do not enter sleep states.
+ */
+ KASSERT((cpu_feature & CPUID_TSC) != 0 && tsc_freq != 0,
+ ("TSC not initialized"));
+ r = rdtsc();
+ for (rx = 0; rx < LOOPS; rx++) {
+ (void)lapic->icr_lo;
+ ia32_pause();
+ }
+ r = rdtsc() - r;
+ r1 = tsc_freq * LOOPS;
+ r2 = r * 1000000;
+ lapic_ipi_wait_mult = r1 >= r2 ? r1 / r2 : 1;
+ if (bootverbose) {
+ printf("LAPIC: ipi_wait() us multiplier %ju (r %ju tsc %ju)\n",
+ (uintmax_t)lapic_ipi_wait_mult, (uintmax_t)r,
+ (uintmax_t)tsc_freq);
+ }
+#undef LOOPS
+#endif /* SMP */
}
/*
@@ -1381,25 +1420,20 @@
* private to the MD code. The public interface for the rest of the
* kernel is defined in mp_machdep.c.
*/
+
+/*
+ * Wait delay microseconds for IPI to be sent. If delay is -1, we
+ * wait forever.
+ */
int
lapic_ipi_wait(int delay)
{
- int x;
+ uint64_t rx;
- /*
- * Wait delay microseconds for IPI to be sent. If delay is
- * -1, we wait forever.
- */
- if (delay == -1) {
- while ((lapic->icr_lo & APIC_DELSTAT_MASK) != APIC_DELSTAT_IDLE)
- ia32_pause();
- return (1);
- }
-
- for (x = 0; x < delay; x += 5) {
+ for (rx = 0; delay == -1 || rx < lapic_ipi_wait_mult * delay; rx++) {
if ((lapic->icr_lo & APIC_DELSTAT_MASK) == APIC_DELSTAT_IDLE)
return (1);
- DELAY(5);
+ ia32_pause();
}
return (0);
}