In a future patch HAS_IOPORT=n will disable inb()/outb() and friends at
compile time. We thus need to add HAS_IOPORT as dependency for those
drivers using them unconditionally. Some 8250 serial drivers support
MMIO only use, so fence only the parts requiring I/O ports and print an
error message if a device can't be supported with the current
configuration.

Co-developed-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
---
 drivers/tty/Kconfig                   |  4 ++--
 drivers/tty/serial/8250/8250_early.c  |  4 ++++
 drivers/tty/serial/8250/8250_pci.c    | 40 +++++++++++++++++++++++++++++++++++
 drivers/tty/serial/8250/8250_pcilib.c | 12 ++++++++++-
 drivers/tty/serial/8250/8250_pcilib.h |  2 ++
 drivers/tty/serial/8250/8250_port.c   | 27 +++++++++++++++++++----
 drivers/tty/serial/8250/Kconfig       |  5 ++---
 drivers/tty/serial/Kconfig            |  2 +-
 include/linux/serial_core.h           |  4 ++++
 9 files changed, 89 insertions(+), 11 deletions(-)

diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index a45d423ad10f02c3a818021bbb18655a8b690500..63a494d36a1fdceba5a7b39f4516060e48af0cc6 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -220,7 +220,7 @@ config MOXA_INTELLIO
 
 config MOXA_SMARTIO
 	tristate "Moxa SmartIO support v. 2.0"
-	depends on SERIAL_NONSTANDARD && PCI
+	depends on SERIAL_NONSTANDARD && PCI && HAS_IOPORT
 	help
 	  Say Y here if you have a Moxa SmartIO multiport serial card and/or
 	  want to help develop a new version of this driver.
@@ -302,7 +302,7 @@ config GOLDFISH_TTY_EARLY_CONSOLE
 
 config IPWIRELESS
 	tristate "IPWireless 3G UMTS PCMCIA card support"
-	depends on PCMCIA && NETDEVICES
+	depends on PCMCIA && NETDEVICES && HAS_IOPORT
 	select PPP
 	help
 	  This is a driver for 3G UMTS PCMCIA card from IPWireless company. In
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
index 6176083d0341ca10edebe5c4eebfffc922a61472..84242292176570cd2c92afbd4755d303827a4abc 100644
--- a/drivers/tty/serial/8250/8250_early.c
+++ b/drivers/tty/serial/8250/8250_early.c
@@ -46,8 +46,10 @@ static unsigned int serial8250_early_in(struct uart_port *port, int offset)
 		return readl(port->membase + offset);
 	case UPIO_MEM32BE:
 		return ioread32be(port->membase + offset);
+#ifdef CONFIG_HAS_IOPORT
 	case UPIO_PORT:
 		return inb(port->iobase + offset);
+#endif
 	default:
 		return 0;
 	}
@@ -70,9 +72,11 @@ static void serial8250_early_out(struct uart_port *port, int offset, int value)
 	case UPIO_MEM32BE:
 		iowrite32be(value, port->membase + offset);
 		break;
+#ifdef CONFIG_HAS_IOPORT
 	case UPIO_PORT:
 		outb(value, port->iobase + offset);
 		break;
+#endif
 	}
 }
 
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 6709b6a5f3011db38acc58dc7223158fe4fcf72e..7d7a6d62c09ceabcf4094d539c565ed09c153561 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -964,6 +964,9 @@ static int pci_ite887x_init(struct pci_dev *dev)
 	struct resource *iobase = NULL;
 	u32 miscr, uartbar, ioport;
 
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(dev);
+
 	/* search for the base-ioport */
 	for (i = 0; i < ARRAY_SIZE(inta_addr); i++) {
 		iobase = request_region(inta_addr[i], ITE_887x_IOSIZE,
@@ -1514,6 +1517,9 @@ static int pci_quatech_init(struct pci_dev *dev)
 	const struct pci_device_id *match;
 	bool amcc = false;
 
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(dev);
+
 	match = pci_match_id(quatech_cards, dev);
 	if (match)
 		amcc = match->driver_data;
@@ -1538,6 +1544,9 @@ static int pci_quatech_setup(struct serial_private *priv,
 		  const struct pciserial_board *board,
 		  struct uart_8250_port *port, int idx)
 {
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(priv->dev);
+
 	/* Needed by pci_quatech calls below */
 	port->port.iobase = pci_resource_start(priv->dev, FL_GET_BASE(board->flags));
 	/* Set up the clocking */
@@ -1655,6 +1664,9 @@ static int pci_fintek_setup(struct serial_private *priv,
 	u8 config_base;
 	u16 iobase;
 
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(pdev);
+
 	config_base = 0x40 + 0x08 * idx;
 
 	/* Get the io address from configuration space */
@@ -1686,6 +1698,9 @@ static int pci_fintek_init(struct pci_dev *dev)
 	u8 config_base;
 	struct serial_private *priv = pci_get_drvdata(dev);
 
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(dev);
+
 	if (!(pci_resource_flags(dev, 5) & IORESOURCE_IO) ||
 			!(pci_resource_flags(dev, 4) & IORESOURCE_IO) ||
 			!(pci_resource_flags(dev, 3) & IORESOURCE_IO))
@@ -1864,6 +1879,9 @@ static int kt_serial_setup(struct serial_private *priv,
 			   const struct pciserial_board *board,
 			   struct uart_8250_port *port, int idx)
 {
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(priv->dev);
+
 	port->port.flags |= UPF_BUG_THRE;
 	port->port.serial_in = kt_serial_in;
 	port->port.handle_break = kt_handle_break;
@@ -1884,6 +1902,9 @@ pci_wch_ch353_setup(struct serial_private *priv,
 		    const struct pciserial_board *board,
 		    struct uart_8250_port *port, int idx)
 {
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(priv->dev);
+
 	port->port.flags |= UPF_FIXED_TYPE;
 	port->port.type = PORT_16550A;
 	return pci_default_setup(priv, board, port, idx);
@@ -1894,6 +1915,9 @@ pci_wch_ch355_setup(struct serial_private *priv,
 		const struct pciserial_board *board,
 		struct uart_8250_port *port, int idx)
 {
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(priv->dev);
+
 	port->port.flags |= UPF_FIXED_TYPE;
 	port->port.type = PORT_16550A;
 	return pci_default_setup(priv, board, port, idx);
@@ -1904,6 +1928,9 @@ pci_wch_ch38x_setup(struct serial_private *priv,
 		    const struct pciserial_board *board,
 		    struct uart_8250_port *port, int idx)
 {
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(priv->dev);
+
 	port->port.flags |= UPF_FIXED_TYPE;
 	port->port.type = PORT_16850;
 	return pci_default_setup(priv, board, port, idx);
@@ -1918,6 +1945,8 @@ static int pci_wch_ch38x_init(struct pci_dev *dev)
 	int max_port;
 	unsigned long iobase;
 
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(dev);
 
 	switch (dev->device) {
 	case 0x3853: /* 8 ports */
@@ -1937,6 +1966,11 @@ static void pci_wch_ch38x_exit(struct pci_dev *dev)
 {
 	unsigned long iobase;
 
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT)) {
+		serial_8250_warn_need_ioport(dev);
+		return;
+	}
+
 	iobase = pci_resource_start(dev, 0);
 	outb(0x0, iobase + CH384_XINT_ENABLE_REG);
 }
@@ -2052,6 +2086,9 @@ static int pci_moxa_init(struct pci_dev *dev)
 	unsigned int i, num_ports = moxa_get_nports(device);
 	u8 val, init_mode = MOXA_RS232;
 
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(dev);
+
 	if (!(pci_moxa_supported_rs(dev) & MOXA_SUPP_RS232)) {
 		init_mode = MOXA_RS422;
 	}
@@ -2084,6 +2121,9 @@ pci_moxa_setup(struct serial_private *priv,
 	unsigned int bar = FL_GET_BASE(board->flags);
 	int offset;
 
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT))
+		return serial_8250_warn_need_ioport(priv->dev);
+
 	if (board->num_ports == 4 && idx == 3)
 		offset = 7 * board->uart_offset;
 	else
diff --git a/drivers/tty/serial/8250/8250_pcilib.c b/drivers/tty/serial/8250/8250_pcilib.c
index ea906d721b2c3eac15c9e8d62cc6fa56c3ef6150..ec4d041778027a0c9f27facbb97c2b74819cfda3 100644
--- a/drivers/tty/serial/8250/8250_pcilib.c
+++ b/drivers/tty/serial/8250/8250_pcilib.c
@@ -12,6 +12,14 @@
 #include "8250.h"
 #include "8250_pcilib.h"
 
+int serial_8250_warn_need_ioport(struct pci_dev *dev)
+{
+	dev_warn(&dev->dev,
+		 "Serial port not supported because of missing I/O resource\n");
+
+	return -ENXIO;
+}
+
 int serial8250_pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port,
 		   u8 bar, unsigned int offset, int regshift)
 {
@@ -27,12 +35,14 @@ int serial8250_pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port,
 		port->port.mapbase = pci_resource_start(dev, bar) + offset;
 		port->port.membase = pcim_iomap_table(dev)[bar] + offset;
 		port->port.regshift = regshift;
-	} else {
+	} else if (IS_ENABLED(CONFIG_HAS_IOPORT)) {
 		port->port.iotype = UPIO_PORT;
 		port->port.iobase = pci_resource_start(dev, bar) + offset;
 		port->port.mapbase = 0;
 		port->port.membase = NULL;
 		port->port.regshift = 0;
+	} else {
+		return serial_8250_warn_need_ioport(dev);
 	}
 	return 0;
 }
diff --git a/drivers/tty/serial/8250/8250_pcilib.h b/drivers/tty/serial/8250/8250_pcilib.h
index 1aaf1b50ce9cc9d78c098e0495838c17eb8752cd..16a274574cdef938fe7700d30b19e75dbbd9b748 100644
--- a/drivers/tty/serial/8250/8250_pcilib.h
+++ b/drivers/tty/serial/8250/8250_pcilib.h
@@ -13,3 +13,5 @@ struct uart_8250_port;
 
 int serial8250_pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port, u8 bar,
 		   unsigned int offset, int regshift);
+
+int serial_8250_warn_need_ioport(struct pci_dev *dev);
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 3509af7dc52b8816f2f5ab58f0d999696f7483e7..91369f542b0bc7fc1d044f24db9a4ac98b394660 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -338,6 +338,7 @@ static void default_serial_dl_write(struct uart_8250_port *up, u32 value)
 	serial_out(up, UART_DLM, value >> 8 & 0xff);
 }
 
+#ifdef CONFIG_HAS_IOPORT
 static unsigned int hub6_serial_in(struct uart_port *p, int offset)
 {
 	offset = offset << p->regshift;
@@ -351,6 +352,7 @@ static void hub6_serial_out(struct uart_port *p, int offset, int value)
 	outb(p->hub6 - 1 + offset, p->iobase);
 	outb(value, p->iobase + 1);
 }
+#endif /* CONFIG_HAS_IOPORT */
 
 static unsigned int mem_serial_in(struct uart_port *p, int offset)
 {
@@ -400,6 +402,7 @@ static unsigned int mem32be_serial_in(struct uart_port *p, int offset)
 	return ioread32be(p->membase + offset);
 }
 
+#ifdef CONFIG_HAS_IOPORT
 static unsigned int io_serial_in(struct uart_port *p, int offset)
 {
 	offset = offset << p->regshift;
@@ -411,6 +414,15 @@ static void io_serial_out(struct uart_port *p, int offset, int value)
 	offset = offset << p->regshift;
 	outb(value, p->iobase + offset);
 }
+#endif
+static unsigned int no_serial_in(struct uart_port *p, int offset)
+{
+	return (unsigned int)-1;
+}
+
+static void no_serial_out(struct uart_port *p, int offset, int value)
+{
+}
 
 static int serial8250_default_handle_irq(struct uart_port *port);
 
@@ -422,10 +434,12 @@ static void set_io_from_upio(struct uart_port *p)
 	up->dl_write = default_serial_dl_write;
 
 	switch (p->iotype) {
+#ifdef CONFIG_HAS_IOPORT
 	case UPIO_HUB6:
 		p->serial_in = hub6_serial_in;
 		p->serial_out = hub6_serial_out;
 		break;
+#endif
 
 	case UPIO_MEM:
 		p->serial_in = mem_serial_in;
@@ -446,11 +460,16 @@ static void set_io_from_upio(struct uart_port *p)
 		p->serial_in = mem32be_serial_in;
 		p->serial_out = mem32be_serial_out;
 		break;
-
-	default:
+#ifdef CONFIG_HAS_IOPORT
+	case UPIO_PORT:
 		p->serial_in = io_serial_in;
 		p->serial_out = io_serial_out;
 		break;
+#endif
+	default:
+		WARN(1, "Unsupported UART type %x\n", p->iotype);
+		p->serial_in = no_serial_in;
+		p->serial_out = no_serial_out;
 	}
 	/* Remember loaded iotype */
 	up->cur_iotype = p->iotype;
@@ -1174,7 +1193,7 @@ static void autoconfig(struct uart_8250_port *up)
 		 */
 		scratch = serial_in(up, UART_IER);
 		serial_out(up, UART_IER, 0);
-#ifdef __i386__
+#if defined(__i386__) && defined(CONFIG_HAS_IOPORT)
 		outb(0xff, 0x080);
 #endif
 		/*
@@ -1183,7 +1202,7 @@ static void autoconfig(struct uart_8250_port *up)
 		 */
 		scratch2 = serial_in(up, UART_IER) & UART_IER_ALL_INTR;
 		serial_out(up, UART_IER, UART_IER_ALL_INTR);
-#ifdef __i386__
+#if defined(__i386__) && defined(CONFIG_HAS_IOPORT)
 		outb(0, 0x080);
 #endif
 		scratch3 = serial_in(up, UART_IER) & UART_IER_ALL_INTR;
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 47ff50763c048c89b19b7c9f13f462bc5368ab43..afa75020d132de2210545fbe54e0d03df4b72a41 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -6,7 +6,6 @@
 
 config SERIAL_8250
 	tristate "8250/16550 and compatible serial support"
-	depends on !S390
 	select SERIAL_CORE
 	select SERIAL_MCTRL_GPIO if GPIOLIB
 	help
@@ -72,7 +71,7 @@ config SERIAL_8250_16550A_VARIANTS
 
 config SERIAL_8250_FINTEK
 	bool "Support for Fintek variants"
-	depends on SERIAL_8250
+	depends on SERIAL_8250 && HAS_IOPORT
 	help
 	  Selecting this option will add support for the RS232 and RS485
 	  capabilities of the Fintek F81216A LPC to 4 UART as well similar
@@ -163,7 +162,7 @@ config SERIAL_8250_HP300
 
 config SERIAL_8250_CS
 	tristate "8250/16550 PCMCIA device support"
-	depends on PCMCIA && SERIAL_8250
+	depends on PCMCIA && SERIAL_8250 && HAS_IOPORT
 	help
 	  Say Y here to enable support for 16-bit PCMCIA serial devices,
 	  including serial port cards, modems, and the modem functions of
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 28e4beeabf8f373fc76e09ea7d1c9d55a66f4964..45f0f779fbf960e9fa66375dbc44c379edc63bef 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -877,7 +877,7 @@ config SERIAL_TXX9_STDSERIAL
 
 config SERIAL_JSM
 	tristate "Digi International NEO and Classic PCI Support"
-	depends on PCI
+	depends on PCI && HAS_IOPORT
 	select SERIAL_CORE
 	help
 	  This is a driver for Digi International's Neo and Classic series
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 4ab65874a850b4402ca3a7d3bdda597d7d5093f9..743b4afaad4c89a6028e592be2cae2643614c89b 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -505,7 +505,11 @@ struct uart_port {
 	 * The remaining bits are serial-core specific and not modifiable by
 	 * userspace.
 	 */
+#ifdef CONFIG_HAS_IOPORT
 #define UPF_FOURPORT		((__force upf_t) ASYNC_FOURPORT       /* 1  */ )
+#else
+#define UPF_FOURPORT		0
+#endif
 #define UPF_SAK			((__force upf_t) ASYNC_SAK            /* 2  */ )
 #define UPF_SPD_HI		((__force upf_t) ASYNC_SPD_HI         /* 4  */ )
 #define UPF_SPD_VHI		((__force upf_t) ASYNC_SPD_VHI        /* 5  */ )

-- 
2.43.0

On Tue, 2024-10-08 at 13:32 +0200, Niklas Schnelle wrote:
> In a future patch HAS_IOPORT=n will disable inb()/outb() and friends at
> compile time. We thus need to add HAS_IOPORT as dependency for those
> drivers using them unconditionally. Some 8250 serial drivers support
> MMIO only use, so fence only the parts requiring I/O ports and print an
> error message if a device can't be supported with the current
> configuration.
> 
> Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> Signed-off-by: Arnd Bergmann <arnd@kernel.org>
> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> ---
> 
---8<---
> diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
> index 47ff50763c048c89b19b7c9f13f462bc5368ab43..afa75020d132de2210545fbe54e0d03df4b72a41 100644
> --- a/drivers/tty/serial/8250/Kconfig
> +++ b/drivers/tty/serial/8250/Kconfig
> @@ -6,7 +6,6 @@
>  
>  config SERIAL_8250
>  	tristate "8250/16550 and compatible serial support"
> -	depends on !S390
>  	select SERIAL_CORE
>  	select SERIAL_MCTRL_GPIO if GPIOLIB
>  	help

Sorry ;-( I didn't mean to commit the above hunk. I always need to
change this for my test compiles and it slipped in. With this series it
all builds but we previously decided we don't want this as part of this
patch. I'll send a v8.