From: Arnd Bergmann <arnd@xxxxxxxx> CONFIG_HAS_IOPORT will soon become optional and cause a build time failure when it is disabled but a driver calls inb()/outb(). At the moment, all architectures that can support ACPI have port I/O, but this is not necessarily the case in the future on non-x86 architectures. The result is a set of errors like: drivers/acpi/osl.c: In function 'acpi_os_read_port': include/asm-generic/io.h:542:14: error: call to '_inb' declared with attribute error: inb()) requires CONFIG_HAS_IOPORT Nothing should actually call these functions in this configuration, and if it does, the result would be undefined behavior today, possibly a NULL pointer dereference. Change the low-level functions to return a proper error code when HAS_IOPORT is disabled. Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/acpi/cppc_acpi.c | 6 ++++-- drivers/acpi/osl.c | 8 ++++++++ 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index b73b3aa92f3f..326b73ae77a9 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1017,7 +1017,8 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val) *val = 0; size = GET_BIT_WIDTH(reg); - if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { + if (IS_ENABLED(CONFIG_HAS_IOPORT) && + reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { u32 val_u32; acpi_status status; @@ -1090,7 +1091,8 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) size = GET_BIT_WIDTH(reg); - if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { + if (IS_ENABLED(CONFIG_HAS_IOPORT) && + reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) { acpi_status status; status = acpi_os_write_port((acpi_io_address)reg->address, diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 70af3fbbebe5..19342ccfabb9 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -642,6 +642,11 @@ acpi_status acpi_os_read_port(acpi_io_address port, u32 *value, u32 width) { u32 dummy; + if (!IS_ENABLED(CONFIG_HAS_IOPORT)) { + *value = BIT_MASK(width); + return AE_NOT_IMPLEMENTED; + } + if (value) *value = 0; else @@ -665,6 +670,9 @@ EXPORT_SYMBOL(acpi_os_read_port); acpi_status acpi_os_write_port(acpi_io_address port, u32 value, u32 width) { + if (!IS_ENABLED(CONFIG_HAS_IOPORT)) + return AE_NOT_IMPLEMENTED; + if (width <= 8) { outb(value, port); } else if (width <= 16) { -- 2.39.5