[PATCH v4 3/3] ns16550: Gate all PCI code with CONFIG_X86

[Rahul Singh <rahul.singh@xxxxxxx>]

The NS16550 driver is assuming that NS16550 PCI card are usable if the
architecture supports PCI (i.e. CONFIG_HAS_PCI=y). However, the code is
very x86 focus and will fail to build on Arm (/!\ it is not all the
errors):

ns16550.c: In function ‘ns16550_init_irq’:
ns16550.c:726:21: error: implicit declaration of function ‘create_irq’;
did you mean ‘release_irq’? [-Werror=implicit-function-declaration]
          uart->irq = create_irq(0, false);
                      ^~~~~~~~~~
                      release_irq
ns16550.c:726:21: error: nested extern declaration of ‘create_irq’
[-Werror=nested-externs]
ns16550.c: In function ‘ns16550_init_postirq’:
ns16550.c:768:33: error: ‘mmio_ro_ranges’ undeclared (first use in this
function); did you mean ‘mmio_handler’?
               rangeset_add_range(mmio_ro_ranges, uart->io_base,
                                  ^~~~~~~~~~~~~~
                                  mmio_handler
ns16550.c:768:33: note: each undeclared identifier is reported only once
for each function it appears in
ns16550.c:780:20: error: variable ‘msi’ has initializer but incomplete
type
              struct msi_info msi = {
                     ^~~~~~~~

Enabling support for NS16550 PCI card on Arm would require more plumbing
in addition to fixing the compilation error.

Arm systems tend to have platform UART available such as NS16550, PL011.
So there are limited reasons to get NS16550 PCI support for now on Arm.

Guard all remaining PCI code that is not under x86 flag with CONFIG_X86.

No functional change intended.

Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>
---

Changes in v4:
- As per the discussion guard all remaining PCI code with CONFIG_X86

---
 xen/drivers/char/ns16550.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
index 9235d854fe..26e601857a 100644
--- a/xen/drivers/char/ns16550.c
+++ b/xen/drivers/char/ns16550.c
@@ -16,7 +16,7 @@
 #include <xen/timer.h>
 #include <xen/serial.h>
 #include <xen/iocap.h>
-#ifdef CONFIG_HAS_PCI
+#if defined(CONFIG_X86) && defined(CONFIG_HAS_PCI)
 #include <xen/pci.h>
 #include <xen/pci_regs.h>
 #include <xen/pci_ids.h>
@@ -51,7 +51,7 @@ static struct ns16550 {
     unsigned int timeout_ms;
     bool_t intr_works;
     bool_t dw_usr_bsy;
-#ifdef CONFIG_HAS_PCI
+#if defined(CONFIG_X86) && defined(CONFIG_HAS_PCI)
     /* PCI card parameters. */
     bool_t pb_bdf_enable;   /* if =1, pb-bdf effective, port behind bridge */
     bool_t ps_bdf_enable;   /* if =1, ps_bdf effective, port on pci card */
@@ -66,7 +66,7 @@ static struct ns16550 {
 #endif
 } ns16550_com[2] = { { 0 } };
 
-#ifdef CONFIG_HAS_PCI
+#if defined(CONFIG_X86) && defined(CONFIG_HAS_PCI)
 struct ns16550_config {
     u16 vendor_id;
     u16 dev_id;
@@ -256,7 +256,7 @@ static int ns16550_getc(struct serial_port *port, char *pc)
 
 static void pci_serial_early_init(struct ns16550 *uart)
 {
-#ifdef CONFIG_HAS_PCI
+#if defined(CONFIG_X86) && defined(CONFIG_HAS_PCI)
     if ( !uart->ps_bdf_enable || uart->io_base >= 0x10000 )
         return;
 
@@ -355,7 +355,7 @@ static void __init ns16550_init_preirq(struct serial_port 
*port)
 
 static void __init ns16550_init_irq(struct serial_port *port)
 {
-#ifdef CONFIG_HAS_PCI
+#if defined(CONFIG_X86) && defined(CONFIG_HAS_PCI)
     struct ns16550 *uart = port->uart;
 
     if ( uart->msi )
@@ -397,7 +397,7 @@ static void __init ns16550_init_postirq(struct serial_port 
*port)
     uart->timeout_ms = max_t(
         unsigned int, 1, (bits * uart->fifo_size * 1000) / uart->baud);
 
-#ifdef CONFIG_HAS_PCI
+#if defined(CONFIG_X86) && defined(CONFIG_HAS_PCI)
     if ( uart->bar || uart->ps_bdf_enable )
     {
         if ( uart->param && uart->param->mmio &&
@@ -477,7 +477,7 @@ static void ns16550_suspend(struct serial_port *port)
 
     stop_timer(&uart->timer);
 
-#ifdef CONFIG_HAS_PCI
+#if defined(CONFIG_X86) && defined(CONFIG_HAS_PCI)
     if ( uart->bar )
        uart->cr = pci_conf_read16(PCI_SBDF(0, uart->ps_bdf[0], uart->ps_bdf[1],
                                   uart->ps_bdf[2]), PCI_COMMAND);
@@ -486,7 +486,7 @@ static void ns16550_suspend(struct serial_port *port)
 
 static void _ns16550_resume(struct serial_port *port)
 {
-#ifdef CONFIG_HAS_PCI
+#if defined(CONFIG_X86) && defined(CONFIG_HAS_PCI)
     struct ns16550 *uart = port->uart;
 
     if ( uart->bar )
-- 
2.17.1