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>
---
v3: fix the returned value and add a comment
---
drivers/acpi/cppc_acpi.c | 6 ++++--
drivers/acpi/osl.c | 12 ++++++++++++
2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 1a40f0514eaa..3757424b715f 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;
@@ -1091,7 +1092,8 @@ 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 78a81969d90e..8ab1802c164b 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -642,6 +642,15 @@ acpi_status acpi_os_read_port(acpi_io_address port, u32 *value, u32 width)
{
u32 dummy;
+ if (!IS_ENABLED(CONFIG_HAS_IOPORT)) {
+ /*
+ * set all-1 result as if reading from non-existing
+ * I/O port
+ */
+ *value = GENMASK(width, 0);
+ return AE_NOT_IMPLEMENTED;
+ }
+
if (value)
*value = 0;
else
@@ -665,6 +674,9 @@ 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
