ich9: implement strap SPKR pin logic

If the signal is sampled high, this indicates that the system is
strapped to the "No Reboot" mode (ICH9 will disable the TCO Timer system
reboot feature). The status of this strap is readable via the NO_REBOOT
bit (CC: offset 0x3410:bit 5).

The NO_REBOOT bit is set when SPKR pin on ICH9 is sampled high. This bit
may be set or cleared by software if the strap is sampled low but may
not override the strap when it indicates "No Reboot".

This patch implements the logic where hardware has ability to set SPKR
pin through a property named "noreboot" and it's sampled high by
default.

Signed-off-by: Paulo Alcantara <pcacjr@zytor.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/acpi/tco.c

@@ -64,7 +64,7 @@ static void tco_timer_expired(void *opaque)
         tr->tco.sts2 |= TCO_BOOT_STS;
         tr->timeouts_no = 0;
 
-        if (!(gcs & ICH9_CC_GCS_NO_REBOOT)) {
+        if (!lpc->pin_strap.spkr_hi && !(gcs & ICH9_CC_GCS_NO_REBOOT)) {
             watchdog_perform_action();
             tco_timer_stop(tr);
             return;

hw/isa/lpc_ich9.c

@@ -692,6 +692,11 @@ static const VMStateDescription vmstate_ich9_lpc = {
     }
 };
 
+static Property ich9_lpc_properties[] = {
+    DEFINE_PROP_BOOL("noreboot", ICH9LPCState, pin_strap.spkr_hi, true),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void ich9_lpc_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -703,6 +708,7 @@ static void ich9_lpc_class_init(ObjectClass *klass, void *data)
     dc->reset = ich9_lpc_reset;
     k->init = ich9_lpc_init;
     dc->vmsd = &vmstate_ich9_lpc;
+    dc->props = ich9_lpc_properties;
     k->config_write = ich9_lpc_config_write;
     dc->desc = "ICH9 LPC bridge";
     k->vendor_id = PCI_VENDOR_ID_INTEL;

include/hw/i386/ich9.h

@@ -46,6 +46,11 @@ typedef struct ICH9LPCState {
     ICH9LPCPMRegs pm;
     uint32_t sci_level; /* track sci level */
 
+    /* 2.24 Pin Straps */
+    struct {
+        bool spkr_hi;
+    } pin_strap;
+
     /* 10.1 Chipset Configuration registers(Memory Space)
      which is pointed by RCBA */
     uint8_t chip_config[ICH9_CC_SIZE];

tests/tco-test.c

@@ -42,6 +42,7 @@ enum {
 
 typedef struct {
     const char *args;
+    bool noreboot;
     QPCIDevice *dev;
     void *lpc_base;
     void *tco_io_base;
@@ -53,7 +54,9 @@ static void test_init(TestData *d)
     QTestState *qs;
     char *s;
 
-    s = g_strdup_printf("-machine q35 %s", !d->args ? "" : d->args);
+    s = g_strdup_printf("-machine q35 %s %s",
+                        d->noreboot ? "" : "-global ICH9-LPC.noreboot=false",
+                        !d->args ? "" : d->args);
     qs = qtest_start(s);
     qtest_irq_intercept_in(qs, "ioapic");
     g_free(s);
@@ -135,6 +138,7 @@ static void test_tco_defaults(void)
     TestData d;
 
     d.args = NULL;
+    d.noreboot = true;
     test_init(&d);
     g_assert_cmpint(qpci_io_readw(d.dev, d.tco_io_base + TCO_RLD), ==,
                     TCO_RLD_DEFAULT);
@@ -167,6 +171,7 @@ static void test_tco_timeout(void)
     int ret;
 
     d.args = NULL;
+    d.noreboot = true;
     test_init(&d);
 
     stop_tco(&d);
@@ -210,6 +215,7 @@ static void test_tco_max_timeout(void)
     int ret;
 
     d.args = NULL;
+    d.noreboot = true;
     test_init(&d);
 
     stop_tco(&d);
@@ -253,6 +259,7 @@ static void test_tco_second_timeout_pause(void)
     QDict *ad;
 
     td.args = "-watchdog-action pause";
+    td.noreboot = false;
     test_init(&td);
 
     stop_tco(&td);
@@ -277,6 +284,7 @@ static void test_tco_second_timeout_reset(void)
     QDict *ad;
 
     td.args = "-watchdog-action reset";
+    td.noreboot = false;
     test_init(&td);
 
     stop_tco(&td);
@@ -301,6 +309,7 @@ static void test_tco_second_timeout_shutdown(void)
     QDict *ad;
 
     td.args = "-watchdog-action shutdown";
+    td.noreboot = false;
     test_init(&td);
 
     stop_tco(&td);
@@ -325,6 +334,7 @@ static void test_tco_second_timeout_none(void)
     QDict *ad;
 
     td.args = "-watchdog-action none";
+    td.noreboot = false;
     test_init(&td);
 
     stop_tco(&td);
@@ -349,6 +359,7 @@ static void test_tco_ticks_counter(void)
     uint16_t rld;
 
     d.args = NULL;
+    d.noreboot = true;
     test_init(&d);
 
     stop_tco(&d);
@@ -375,6 +386,7 @@ static void test_tco1_control_bits(void)
     uint16_t val;
 
     d.args = NULL;
+    d.noreboot = true;
     test_init(&d);
 
     val = TCO_LOCK;
@@ -394,6 +406,7 @@ static void test_tco1_status_bits(void)
     int ret;
 
     d.args = NULL;
+    d.noreboot = true;
     test_init(&d);
 
     stop_tco(&d);
@@ -421,7 +434,8 @@ static void test_tco2_status_bits(void)
     uint16_t val;
     int ret;
 
-    d.args = "-watchdog-action none";
+    d.args = NULL;
+    d.noreboot = true;
     test_init(&d);
 
     stop_tco(&d);