From: Arnd Bergmann <a...@arndb.de>
arch/um is one of the last users of CONFIG_GENERIC_IOMAP, but upon
closer look it appears that the PCI host bridge does not register
any port I/O, and the absense of both custom inb/outb functions and
a PCI_IOBASE constant means that actually trying to use port I/O
results on a NULL pointer access.
Build testing with clang confirms this by warning about this exact
problem:
include/asm-generic/io.h:549:31: error: performing pointer arithmetic on a null
pointer has undefined behavior [-Werror,-Wnull-pointer-arithmetic]
549 | val = __raw_readb(PCI_IOBASE + addr);
| ~~~~~~~~~~ ^
Remove all the Kconfig selects that refer to legacy port I/O
and instead just build the normal MMIO path that is emulated
by the virtio PCI host.
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
arch/um/Kconfig | 6 ------
arch/um/kernel/Makefile | 1 -
arch/um/kernel/ioport.c | 13 -------------
3 files changed, 20 deletions(-)
delete mode 100644 arch/um/kernel/ioport.c
diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index 79509c7f39de..f08e8a7fac93 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -52,13 +52,7 @@ config NO_IOMEM
config UML_IOMEM_EMULATION
bool
select INDIRECT_IOMEM
- select HAS_IOPORT
select GENERIC_PCI_IOMAP
- select GENERIC_IOMAP
- select NO_GENERIC_PCI_IOPORT_MAP
-
-config NO_IOPORT_MAP
- def_bool !UML_IOMEM_EMULATION
config ISA
bool
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index 4df1cd0d2017..4669db2aa9be 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -25,7 +25,6 @@ obj-$(CONFIG_GPROF) += gprof_syms.o
obj-$(CONFIG_OF) += dtb.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
-obj-$(CONFIG_GENERIC_PCI_IOMAP) += ioport.o
USER_OBJS := config.o
diff --git a/arch/um/kernel/ioport.c b/arch/um/kernel/ioport.c
deleted file mode 100644
index 7220615b3beb..000000000000
--- a/arch/um/kernel/ioport.c
+++ /dev/null
@@ -1,13 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2021 Intel Corporation
- * Author: Johannes Berg <johan...@sipsolutions.net>
- */
-#include <asm/iomap.h>
-#include <asm-generic/pci_iomap.h>
-
-void __iomem *__pci_ioport_map(struct pci_dev *dev, unsigned long port,
- unsigned int nr)
-{
- return NULL;
-}
--
2.39.5
