Merge branch 'stable', skiboot-5.0.1

4 files changed, 36 insertions, 20 deletions

diff --git a/hw/bt.c b/hw/bt.c
index 7bf1b2f..8bb44cd 100644
--- a/hw/bt.c
+++ b/hw/bt.c
@@ -350,7 +350,8 @@ static void print_debug_queue_info(void) {}
 
 static void bt_send_and_unlock(void)
 {
-	if (bt.state == BT_STATE_IDLE && !list_empty(&bt.msgq))
+	if (lpc_ok() &&
+	    bt.state == BT_STATE_IDLE && !list_empty(&bt.msgq))
 		bt_send_msg();
 
 	unlock(&bt.lock);
@@ -361,6 +362,10 @@ static void bt_poll(struct timer *t __unused, void *data __unused)
 {
 	uint8_t bt_ctrl;
 
+	/* Don't do anything if the LPC bus is offline */
+	if (!lpc_ok())
+		return;
+
 	/* If we can't get the lock assume someone else will notice
 	 * the new message and process it. */
 	lock(&bt.lock);
@@ -440,7 +445,9 @@ static int bt_add_ipmi_msg(struct ipmi_msg *ipmi_msg)
 
 void bt_irq(void)
 {
-	uint8_t ireg = bt_inb(BT_INTMASK);
+	uint8_t ireg;
+
+	ireg = bt_inb(BT_INTMASK);
 
 	bt.irq_ok = true;
 	if (ireg & BT_INTMASK_B2H_IRQ) {
diff --git a/hw/lpc-uart.c b/hw/lpc-uart.c
index 2e6114a..7c3190e 100644
--- a/hw/lpc-uart.c
+++ b/hw/lpc-uart.c
@@ -135,6 +135,10 @@ static size_t uart_con_write(const char *buf, size_t len)
 {
 	size_t written = 0;
 
+	/* If LPC bus is bad, we just swallow data */
+	if (!lpc_ok())
+		return written;
+
 	lock(&uart_lock);
 	while(written < len) {
 		if (tx_room == 0) {
diff --git a/hw/lpc.c b/hw/lpc.c
index 0db674f..b287020 100644
--- a/hw/lpc.c
+++ b/hw/lpc.c
@@ -500,3 +500,15 @@ void lpc_used_by_console(void)
 		unlock(&chip->lpc_lock);
 	}
 }
+
+bool lpc_ok(void)
+{
+	struct proc_chip *chip;
+
+	if (lpc_default_chip_id < 0)
+		return false;
+	if (!xscom_ok())
+		return false;
+	chip = get_chip(lpc_default_chip_id);
+	return !lock_held_by_me(&chip->lpc_lock);
+}
diff --git a/hw/xscom.c b/hw/xscom.c
index 4815ce1..c023a9d 100644
--- a/hw/xscom.c
+++ b/hw/xscom.c
@@ -342,7 +342,6 @@ static uint32_t xscom_decode_chiplet(uint32_t partid, uint64_t *pcb_addr)
  */
 int xscom_read(uint32_t partid, uint64_t pcb_addr, uint64_t *val)
 {
-	bool need_unlock;
 	uint32_t gcid;
 	int rc;
 
@@ -360,12 +359,8 @@ int xscom_read(uint32_t partid, uint64_t pcb_addr, uint64_t *val)
 		return OPAL_PARAMETER;
 	}
 
-	/*
-	 * HW822317 requires locking. We use a recursive lock as error
-	 * conditions might cause printf's which might then try to take
-	 * the lock again
-	 */
-	need_unlock = lock_recursive(&xscom_lock);
+	/* HW822317 requires us to do global locking */
+	lock(&xscom_lock);
 
 	/* Direct vs indirect access */
 	if (pcb_addr & XSCOM_ADDR_IND_FLAG)
@@ -374,8 +369,7 @@ int xscom_read(uint32_t partid, uint64_t pcb_addr, uint64_t *val)
 		rc = __xscom_read(gcid, pcb_addr & 0x7fffffff, val);
 
 	/* Unlock it */
-	if (need_unlock)
-		unlock(&xscom_lock);
+	unlock(&xscom_lock);
 	return rc;
 }
 
@@ -383,7 +377,6 @@ opal_call(OPAL_XSCOM_READ, xscom_read, 3);
 
 int xscom_write(uint32_t partid, uint64_t pcb_addr, uint64_t val)
 {
-	bool need_unlock;
 	uint32_t gcid;
 	int rc;
 
@@ -401,12 +394,8 @@ int xscom_write(uint32_t partid, uint64_t pcb_addr, uint64_t val)
 		return OPAL_PARAMETER;
 	}
 
-	/*
-	 * HW822317 requires locking. We use a recursive lock as error
-	 * conditions might cause printf's which might then try to take
-	 * the lock again
-	 */
-	need_unlock = lock_recursive(&xscom_lock);
+	/* HW822317 requires us to do global locking */
+	lock(&xscom_lock);
 
 	/* Direct vs indirect access */
 	if (pcb_addr & XSCOM_ADDR_IND_FLAG)
@@ -415,8 +404,7 @@ int xscom_write(uint32_t partid, uint64_t pcb_addr, uint64_t val)
 		rc = __xscom_write(gcid, pcb_addr & 0x7fffffff, val);
 
 	/* Unlock it */
-	if (need_unlock)
-		unlock(&xscom_lock);
+	unlock(&xscom_lock);
 	return rc;
 }
 opal_call(OPAL_XSCOM_WRITE, xscom_write, 3);
@@ -546,3 +534,8 @@ void xscom_used_by_console(void)
 	lock(&xscom_lock);
 	unlock(&xscom_lock);
 }
+
+bool xscom_ok(void)
+{
+	return !lock_held_by_me(&xscom_lock);
+}