Enable throttling/C3 quirks for PIIX4 parts. Defer checking quirks until

after boot so that PCI is initialized and we can probe for the problem
chipsets.  Note that while probed but unusable states are disabled, they
aren't freed yet.  In the future, it may make sense to detach them.

Tested by:	Adam K Kirchoff <adamk at voicenet com>
MFC after:	2 days

1 files changed, 21 insertions, 9 deletions

diff --git a/sys/dev/acpica/acpi_cpu.c b/sys/dev/acpica/acpi_cpu.c
index 23d20d8..471638a 100644
--- a/sys/dev/acpica/acpi_cpu.c
+++ b/sys/dev/acpica/acpi_cpu.c
@@ -299,10 +299,6 @@ acpi_cpu_attach(device_t dev)
 				SYSCTL_CHILDREN(acpi_sc->acpi_sysctl_tree),
 				OID_AUTO, "cpu", CTLFLAG_RD, 0, "");
 
-    /* If this is the first device probed, check for quirks. */
-    if (device_get_unit(dev) == 0)
-	acpi_cpu_quirks(sc);
-
     /*
      * Probe for throttling and Cx state support.
      * If none of these is present, free up unused resources.
@@ -674,6 +670,10 @@ acpi_cpu_startup(void *arg)
     /* Get set of CPU devices */
     devclass_get_devices(acpi_cpu_devclass, &cpu_devices, &cpu_ndevices);
 
+    /* Check for quirks via the first CPU device. */
+    sc = device_get_softc(cpu_devices[0]);
+    acpi_cpu_quirks(sc);
+
     /*
      * Make sure all the processors' Cx counts match.  We should probably
      * also check the contents of each.  However, no known systems have
@@ -702,6 +702,10 @@ static void
 acpi_cpu_startup_throttling()
 {
 
+    /* If throttling is not usable, don't initialize it. */
+    if (cpu_quirks & CPU_QUIRK_NO_THROTTLE)
+	return;
+
     /* Initialise throttling states */
     cpu_throttle_max = CPU_MAX_SPEED;
     cpu_throttle_state = CPU_MAX_SPEED;
@@ -737,13 +741,22 @@ static void
 acpi_cpu_startup_cx()
 {
     struct acpi_cpu_softc *sc;
-    struct sbuf		 sb;
+    struct sbuf sb;
     int i;
 
+    /*
+     * Set up the list of Cx states, eliminating C3 states by truncating
+     * cpu_cx_count if quirks indicate C3 is not usable.
+     */
     sc = device_get_softc(cpu_devices[0]);
     sbuf_new(&sb, cpu_cx_supported, sizeof(cpu_cx_supported), SBUF_FIXEDLEN);
-    for (i = 0; i < cpu_cx_count; i++)
-	sbuf_printf(&sb, "C%d/%d ", i + 1, sc->cpu_cx_states[i].trans_lat);
+    for (i = 0; i < cpu_cx_count; i++) {
+	if ((cpu_quirks & CPU_QUIRK_NO_C3) == 0 ||
+	    sc->cpu_cx_states[i].type != ACPI_STATE_C3)
+	    sbuf_printf(&sb, "C%d/%d ", i + 1, sc->cpu_cx_states[i].trans_lat);
+	else
+	    cpu_cx_count = i;
+    }
     sbuf_trim(&sb);
     sbuf_finish(&sb);
     SYSCTL_ADD_STRING(&acpi_cpu_sysctl_ctx,
@@ -966,6 +979,7 @@ acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context)
 static int
 acpi_cpu_quirks(struct acpi_cpu_softc *sc)
 {
+    device_t acpi_dev;
 
     /*
      * C3 on multiple CPUs requires using the expensive flush cache
@@ -974,7 +988,6 @@ acpi_cpu_quirks(struct acpi_cpu_softc *sc)
     if (mp_ncpus > 1)
 	cpu_quirks |= CPU_QUIRK_NO_BM_CTRL;
 
-#ifdef notyet
     /* Look for various quirks of the PIIX4 part. */
     acpi_dev = pci_find_device(PCI_VENDOR_INTEL, PCI_DEVICE_82371AB_3);
     if (acpi_dev != NULL) {
@@ -1011,7 +1024,6 @@ acpi_cpu_quirks(struct acpi_cpu_softc *sc)
 	    break;
 	}
     }
-#endif
 
     return (0);
 }