serial: 8250: Decouple RSA probe

Prepare for 8250 split; separate RSA probe and resource management
from base port operations. Override base port operations for the
config_port(), request_port() and release_port() methods to
implement the optional RSA probe and resource management only in
the universal/legacy 8250 driver.

Introduce 'probe' flags for 8250 ports, which allows drivers higher
up the driver stack to enable optional probes.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 76 insertions, 39 deletions

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 23dc9f9b9839..c43f74c53cd9 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -84,9 +84,6 @@ struct serial8250_config {
 #define UART_BUG_THRE   (1 << 3)        /* UART has buggy THRE reassertion */
 #define UART_BUG_PARITY (1 << 4)        /* UART mishandles parity if FIFO enabled */
 
-#define PROBE_RSA       (1 << 0)
-#define PROBE_ANY       (~0)
-
 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
 
 #ifdef CONFIG_SERIAL_8250_SHARE_IRQ
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 257e373bfccd..a4ed84a4f8db 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1105,7 +1105,7 @@ static void autoconfig_16550a(struct uart_8250_port *up)
  * whether or not this UART is a 16550A or not, since this will
  * determine whether or not we can use its FIFO features or not.
  */
-static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
+static void autoconfig(struct uart_8250_port *up)
 {
         unsigned char status1, scratch, scratch2, scratch3;
         unsigned char save_lcr, save_mcr;
@@ -1228,7 +1228,7 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
         /*
          * Only probe for RSA ports if we got the region.
          */
-        if (port->type == PORT_16550A && probeflags & PROBE_RSA &&
+        if (port->type == PORT_16550A && up->probe & UART_PROBE_RSA &&
             __enable_rsa(up))
                 port->type = PORT_RSA;
 #endif
@@ -2832,10 +2832,6 @@ static void serial8250_release_port(struct uart_port *port)
         struct uart_8250_port *up = up_to_u8250p(port);
 
         serial8250_release_std_resource(up);
-#ifdef CONFIG_SERIAL_8250_RSA
-        if (port->type == PORT_RSA)
-                serial8250_release_rsa_resource(up);
-#endif
 }
 
 static int serial8250_request_port(struct uart_port *port)
@@ -2847,13 +2843,6 @@ static int serial8250_request_port(struct uart_port *port)
                 return -ENODEV;
 
         ret = serial8250_request_std_resource(up);
-#ifdef CONFIG_SERIAL_8250_RSA
-        if (ret == 0 && port->type == PORT_RSA) {
-                ret = serial8250_request_rsa_resource(up);
-                if (ret < 0)
-                        serial8250_release_std_resource(up);
-        }
-#endif
 
         return ret;
 }
@@ -3001,7 +2990,6 @@ static void register_dev_spec_attr_grp(struct uart_8250_port *up)
 static void serial8250_config_port(struct uart_port *port, int flags)
 {
         struct uart_8250_port *up = up_to_u8250p(port);
-        int probeflags = 0;
         int ret;
 
         if (port->type == PORT_8250_CIR)
@@ -3015,28 +3003,11 @@ static void serial8250_config_port(struct uart_port *port, int flags)
         if (ret < 0)
                 return;
 
-#ifdef CONFIG_SERIAL_8250_RSA
-        if (port->type == PORT_RSA) {
-                if (serial8250_request_rsa_resource(up) == 0)
-                        probeflags |= PROBE_RSA;
-        } else if (flags & UART_CONFIG_TYPE) {
-                int i;
-
-                for (i = 0 ; i < probe_rsa_count; ++i) {
-                        if (probe_rsa[i] == port->iobase) {
-                                if (serial8250_request_rsa_resource(up) == 0)
-                                        probeflags |= PROBE_RSA;
-                                break;
-                        }
-                }
-        }
-#endif
-
         if (port->iotype != up->cur_iotype)
                 set_io_from_upio(port);
 
         if (flags & UART_CONFIG_TYPE)
-                autoconfig(up, probeflags);
+                autoconfig(up);
 
         /* if access method is AU, it is a 16550 with a quirk */
         if (port->type == PORT_16550A && port->iotype == UPIO_AU)
@@ -3049,10 +3020,6 @@ static void serial8250_config_port(struct uart_port *port, int flags)
         if (port->type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
                 autoconfig_irq(up);
 
-#ifdef CONFIG_SERIAL_8250_RSA
-        if (port->type != PORT_RSA && probeflags & PROBE_RSA)
-                serial8250_release_rsa_resource(up);
-#endif
         if (port->type == PORT_UNKNOWN)
                 serial8250_release_std_resource(up);
 
@@ -3113,6 +3080,9 @@ static struct uart_ops serial8250_pops = {
 #endif
 };
 
+static const struct uart_ops *base_ops;
+static struct uart_ops univ8250_port_ops;
+
 static const struct uart_8250_ops univ8250_driver_ops = {
         .setup_irq      = univ8250_setup_irq,
         .release_irq    = univ8250_release_irq,
@@ -3184,6 +3154,69 @@ static void serial8250_set_defaults(struct uart_8250_port *up)
         }
 }
 
+#ifdef CONFIG_SERIAL_8250_RSA
+
+static void univ8250_config_port(struct uart_port *port, int flags)
+{
+        struct uart_8250_port *up = up_to_u8250p(port);
+
+        up->probe &= ~UART_PROBE_RSA;
+        if (port->type == PORT_RSA) {
+                if (serial8250_request_rsa_resource(up) == 0)
+                        up->probe |= UART_PROBE_RSA;
+        } else if (flags & UART_CONFIG_TYPE) {
+                int i;
+
+                for (i = 0; i < probe_rsa_count; i++) {
+                        if (probe_rsa[i] == up->port.iobase) {
+                                if (serial8250_request_rsa_resource(up) == 0)
+                                        up->probe |= UART_PROBE_RSA;
+                                break;
+                        }
+                }
+        }
+
+        base_ops->config_port(port, flags);
+
+        if (port->type != PORT_RSA && up->probe & UART_PROBE_RSA)
+                serial8250_release_rsa_resource(up);
+}
+
+static int univ8250_request_port(struct uart_port *port)
+{
+        struct uart_8250_port *up = up_to_u8250p(port);
+        int ret;
+
+        ret = base_ops->request_port(port);
+        if (ret == 0 && port->type == PORT_RSA) {
+                ret = serial8250_request_rsa_resource(up);
+                if (ret < 0)
+                        base_ops->release_port(port);
+        }
+
+        return ret;
+}
+
+static void univ8250_release_port(struct uart_port *port)
+{
+        struct uart_8250_port *up = up_to_u8250p(port);
+
+        if (port->type == PORT_RSA)
+                serial8250_release_rsa_resource(up);
+        base_ops->release_port(port);
+}
+
+static void univ8250_rsa_support(struct uart_ops *ops)
+{
+        ops->config_port  = univ8250_config_port;
+        ops->request_port = univ8250_request_port;
+        ops->release_port = univ8250_release_port;
+}
+
+#else
+#define univ8250_rsa_support(x)         do { } while (0)
+#endif /* CONFIG_SERIAL_8250_RSA */
+
 static void __init serial8250_isa_init_ports(void)
 {
         struct uart_8250_port *up;
@@ -3203,6 +3236,9 @@ static void __init serial8250_isa_init_ports(void)
 
                 port->line = i;
                 serial8250_init_port(up);
+                if (!base_ops)
+                        base_ops = port->ops;
+                port->ops = &univ8250_port_ops;
 
                 init_timer(&up->timer);
                 up->timer.function = serial8250_timeout;
@@ -3216,6 +3252,10 @@ static void __init serial8250_isa_init_ports(void)
                 up->mcr_force = ALPHA_KLUDGE_MCR;
         }
 
+        /* chain base port ops to support Remote Supervisor Adapter */
+        univ8250_port_ops = *base_ops;
+        univ8250_rsa_support(&univ8250_port_ops);
+
         if (share_irqs)
                 irqflag = IRQF_SHARED;