Merge tag 'please-pull-apei' into x86/ras

APEI is currently implemented so that it depends on x86 hardware.
The primary dependency is that GHES uses the x86 NMI for hardware
error notification and MCE for memory error handling. These patches
remove that dependency.

Other APEI features such as error reporting via external IRQ, error
serialization, or error injection, do not require changes to use them
on non-x86 architectures.

The following patch set eliminates the APEI Kconfig x86 dependency
by making these changes:
- treat NMI notification as GHES architecture - HAVE_ACPI_APEI_NMI
- group and wrap around #ifdef CONFIG_HAVE_ACPI_APEI_NMI code which
  is used only for NMI path
- identify architectural boxes and abstract it accordingly (tlb flush and MCE)
- rework ioremap for both IRQ and NMI context

NMI code is kept in ghes.c file since NMI and IRQ context are tightly coupled.

Note, these patches introduce no functional changes for x86. The NMI notification
feature is hard selected for x86. Architectures that want to use this
feature should also provide NMI code infrastructure.

8 files changed, 20 insertions, 5 deletions

diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
index c9f5c9dcc15c..008c223eaf26 100644
--- a/drivers/tty/serial/arc_uart.c
+++ b/drivers/tty/serial/arc_uart.c
@@ -177,7 +177,7 @@ static void arc_serial_tx_chars(struct arc_uart_port *uart)
 		uart->port.icount.tx++;
 		uart->port.x_char = 0;
 		sent = 1;
-	} else if (xmit->tail != xmit->head) {	/* TODO: uart_circ_empty */
+	} else if (!uart_circ_empty(xmit)) {
 		ch = xmit->buf[xmit->tail];
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 		uart->port.icount.tx++;
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index e2f93874989b..044e86d528ae 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -567,6 +567,9 @@ static void imx_start_tx(struct uart_port *port)
 	struct imx_port *sport = (struct imx_port *)port;
 	unsigned long temp;
 
+	if (uart_circ_empty(&port->state->xmit))
+		return;
+
 	if (USE_IRDA(sport)) {
 		/* half duplex in IrDA mode; have to disable receive mode */
 		temp = readl(sport->port.membase + UCR4);
diff --git a/drivers/tty/serial/ip22zilog.c b/drivers/tty/serial/ip22zilog.c
index 1efd4c36ba0c..99b7b8697861 100644
--- a/drivers/tty/serial/ip22zilog.c
+++ b/drivers/tty/serial/ip22zilog.c
@@ -603,6 +603,8 @@ static void ip22zilog_start_tx(struct uart_port *port)
 	} else {
 		struct circ_buf *xmit = &port->state->xmit;
 
+		if (uart_circ_empty(xmit))
+			return;
 		writeb(xmit->buf[xmit->tail], &channel->data);
 		ZSDELAY();
 		ZS_WSYNC(channel);
diff --git a/drivers/tty/serial/m32r_sio.c b/drivers/tty/serial/m32r_sio.c
index 68f2c53e0b54..5702828fb62e 100644
--- a/drivers/tty/serial/m32r_sio.c
+++ b/drivers/tty/serial/m32r_sio.c
@@ -266,9 +266,11 @@ static void m32r_sio_start_tx(struct uart_port *port)
 	if (!(up->ier & UART_IER_THRI)) {
 		up->ier |= UART_IER_THRI;
 		serial_out(up, UART_IER, up->ier);
-		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
-		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
-		up->port.icount.tx++;
+		if (!uart_circ_empty(xmit)) {
+			serial_out(up, UART_TX, xmit->buf[xmit->tail]);
+			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+			up->port.icount.tx++;
+		}
 	}
 	while((serial_in(up, UART_LSR) & UART_EMPTY) != UART_EMPTY);
 #else
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index c41aca4dfc43..72000a6d5af0 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -991,7 +991,7 @@ static const struct of_device_id msm_uartdm_table[] = {
 	{ }
 };
 
-static int __init msm_serial_probe(struct platform_device *pdev)
+static int msm_serial_probe(struct platform_device *pdev)
 {
 	struct msm_port *msm_port;
 	struct resource *resource;
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index 8193635103ee..f7ad5b903055 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -653,6 +653,8 @@ static void pmz_start_tx(struct uart_port *port)
 	} else {
 		struct circ_buf *xmit = &port->state->xmit;
 
+		if (uart_circ_empty(xmit))
+			goto out;
 		write_zsdata(uap, xmit->buf[xmit->tail]);
 		zssync(uap);
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
@@ -661,6 +663,7 @@ static void pmz_start_tx(struct uart_port *port)
 		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 			uart_write_wakeup(&uap->port);
 	}
+ out:
 	pmz_debug("pmz: start_tx() done.\n");
 }
 
diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
index 80a58eca785b..2f57df9a71d9 100644
--- a/drivers/tty/serial/sunsab.c
+++ b/drivers/tty/serial/sunsab.c
@@ -427,6 +427,9 @@ static void sunsab_start_tx(struct uart_port *port)
 	struct circ_buf *xmit = &up->port.state->xmit;
 	int i;
 
+	if (uart_circ_empty(xmit))
+		return;
+
 	up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
 	writeb(up->interrupt_mask1, &up->regs->w.imr1);
 	
diff --git a/drivers/tty/serial/sunzilog.c b/drivers/tty/serial/sunzilog.c
index a85db8b87156..02df3940b95e 100644
--- a/drivers/tty/serial/sunzilog.c
+++ b/drivers/tty/serial/sunzilog.c
@@ -703,6 +703,8 @@ static void sunzilog_start_tx(struct uart_port *port)
 	} else {
 		struct circ_buf *xmit = &port->state->xmit;
 
+		if (uart_circ_empty(xmit))
+			return;
 		writeb(xmit->buf[xmit->tail], &channel->data);
 		ZSDELAY();
 		ZS_WSYNC(channel);