Re: [PATCH 5/6] mips: drop GENERIC_IOMAP wrapper
On Tue, Mar 18, 2025 at 10:13:35PM +0100, Arnd Bergmann wrote: > Thanks for the report, I missed that the generic ioport_map() function > is missing the PCI_IOBASE macro, we should probably remove that from > the asm-generic/io.h header and require architectures to define it > themselves, since the NULL fallback is pretty much always wrong. > > There is also a type mismatch between the MIPS > PCI_IOBASE/mips_io_port_base and the one that asm-generic/io.h > expects, so I had to add a couple of extra typecasts, which > makes it rather ugly, but the change below seems to work. Thanks, that does make the -Wnull-pointer-arithmetic warnings disappear. That build still fails in next-20250319 (which includes that change) at the end with: $ make -skj"$(nproc)" ARCH=mips CROSS_COMPILE=mips-linux- mrproper malta_defconfig all ERROR: modpost: "pci_iounmap" [drivers/net/wireless/intel/ipw2x00/ipw2100.ko] undefined! which appears related to this original change. Cheers, Nathan
Re: [PATCH 5/6] mips: drop GENERIC_IOMAP wrapper
On Wed, Mar 19, 2025, at 18:30, Nathan Chancellor wrote: > On Tue, Mar 18, 2025 at 10:13:35PM +0100, Arnd Bergmann wrote: >> Thanks for the report, I missed that the generic ioport_map() function >> is missing the PCI_IOBASE macro, we should probably remove that from >> the asm-generic/io.h header and require architectures to define it >> themselves, since the NULL fallback is pretty much always wrong. >> >> There is also a type mismatch between the MIPS >> PCI_IOBASE/mips_io_port_base and the one that asm-generic/io.h >> expects, so I had to add a couple of extra typecasts, which >> makes it rather ugly, but the change below seems to work. > > Thanks, that does make the -Wnull-pointer-arithmetic warnings disappear. > That build still fails in next-20250319 (which includes that change) at > the end with: > > $ make -skj"$(nproc)" ARCH=mips CROSS_COMPILE=mips-linux- mrproper > malta_defconfig all > ERROR: modpost: "pci_iounmap" > [drivers/net/wireless/intel/ipw2x00/ipw2100.ko] undefined! > > which appears related to this original change. Right, I had seen and fixed a problem like this in an earlier version, but forgot the EXPORT_SYMBOL on the legacy host version. Fixed it better now. Arnd
Re: [PATCH 5/6] mips: drop GENERIC_IOMAP wrapper
On Tue, Mar 18, 2025, at 21:39, Nathan Chancellor wrote:
> On Sat, Mar 15, 2025 at 11:59:06AM +0100, Arnd Bergmann wrote:
>> From: Arnd Bergmann
>> diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
>> void __ioread64_copy(void *to, const void __iomem *from, size_t count);
>>
>> +#ifdef CONFIG_PCI_DRIVERS_LEGACY
>> +struct pci_dev;
>> +void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
>> +#define pci_iounmap pci_iounmap
>> +#endif
>> +
>> #include
>>
>> static inline void *isa_bus_to_virt(unsigned long address)
>> diff --git a/arch/mips/lib/iomap-pci.c b/arch/mips/lib/iomap-pci.c
>> index a9cb28813f0b..2f82c776c6d0 100644
>> --- a/arch/mips/lib/iomap-pci.c
>> +++ b/arch/mips/lib/iomap-pci.c
>> @@ -43,4 +43,13 @@ void __iomem *__pci_ioport_map(struct pci_dev *dev,
>> return (void __iomem *) (ctrl->io_map_base + port);
>> }
>>
>> +void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
>> +{
>> +struct pci_controller *ctrl = dev->bus->sysdata;
>> +void __iomem *base = (void __iomem *)ctrl->io_map_base;
>> +
>> +if (addr < base || addr > (base + resource_size(ctrl->io_resource)))
>> +iounmap(addr);
>> +}
>> +
>> #endif /* CONFIG_PCI_DRIVERS_LEGACY */
>> --
>> 2.39.5
>>
>
> This change as commit 976bf3aec388 ("mips: drop GENERIC_IOMAP wrapper") in
> -next introduces new instances of -Wnull-pointer-arithmetic when building
> certain mips configurations with clang.
>
Thanks for the report, I missed that the generic ioport_map() function
is missing the PCI_IOBASE macro, we should probably remove that from
the asm-generic/io.h header and require architectures to define it
themselves, since the NULL fallback is pretty much always wrong.
There is also a type mismatch between the MIPS
PCI_IOBASE/mips_io_port_base and the one that asm-generic/io.h
expects, so I had to add a couple of extra typecasts, which
makes it rather ugly, but the change below seems to work.
Arnd
diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 1fe56d1870a6..78c6573f91f2 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -544,12 +544,16 @@ extern void (*_dma_cache_inv)(unsigned long start,
unsigned long size);
void __ioread64_copy(void *to, const void __iomem *from, size_t count);
-#ifdef CONFIG_PCI_DRIVERS_LEGACY
+#if defined(CONFIG_PCI) && defined(CONFIG_PCI_DRIVERS_LEGACY)
struct pci_dev;
void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
#define pci_iounmap pci_iounmap
#endif
+#ifndef PCI_IOBASE
+#define PCI_IOBASE ((void __iomem *)mips_io_port_base)
+#endif
+
#include
static inline void *isa_bus_to_virt(unsigned long address)
diff --git a/arch/mips/include/asm/mach-loongson64/spaces.h
b/arch/mips/include/asm/mach-loongson64/spaces.h
index ce04e998a37b..dbd26db5f2c5 100644
--- a/arch/mips/include/asm/mach-loongson64/spaces.h
+++ b/arch/mips/include/asm/mach-loongson64/spaces.h
@@ -7,9 +7,10 @@
#endif /* CONFIG_64BIT */
/* Skip 128k to trap NULL pointer dereferences */
-#define PCI_IOBASE _AC(0xc000 + SZ_128K, UL)
+#define PCI_PORT_BASE _AC(0xc000 + SZ_128K, UL)
+#define PCI_IOBASE (void __iomem *)PCI_PORT_BASE
#define PCI_IOSIZE SZ_16M
-#define MAP_BASE (PCI_IOBASE + PCI_IOSIZE)
+#define MAP_BASE (PCI_PORT_BASE + PCI_IOSIZE)
#define IO_SPACE_LIMIT (PCI_IOSIZE - 1)
diff --git a/arch/mips/include/asm/mach-ralink/spaces.h
b/arch/mips/include/asm/mach-ralink/spaces.h
index a9f0570d0f04..a63d106c89c6 100644
--- a/arch/mips/include/asm/mach-ralink/spaces.h
+++ b/arch/mips/include/asm/mach-ralink/spaces.h
@@ -2,7 +2,7 @@
#ifndef __ASM_MACH_RALINK_SPACES_H_
#define __ASM_MACH_RALINK_SPACES_H_
-#define PCI_IOBASE mips_io_port_base
+#define PCI_IOBASE (void __iomem *)mips_io_port_base
#define PCI_IOSIZE SZ_64K
#define IO_SPACE_LIMIT (PCI_IOSIZE - 1)
diff --git a/arch/mips/loongson64/init.c b/arch/mips/loongson64/init.c
index a35dd7311795..b9f90f33fc9a 100644
--- a/arch/mips/loongson64/init.c
+++ b/arch/mips/loongson64/init.c
@@ -128,7 +128,7 @@ void __init prom_init(void)
}
/* init base address of io space */
- set_io_port_base(PCI_IOBASE);
+ set_io_port_base((unsigned long)PCI_IOBASE);
if (loongson_sysconf.early_config)
loongson_sysconf.early_config();
@@ -178,7 +178,7 @@ static int __init add_legacy_isa_io(struct fwnode_handle
*fwnode, resource_size_
return -EINVAL;
}
- vaddr = PCI_IOBASE + range->io_start;
+ vaddr = (unsigned long)PCI_IOBASE + range->io_start;
vmap_page_range(vaddr, vaddr + size, hw_start,
pgprot_device(PAGE_KERNEL));
Re: [PATCH 5/6] mips: drop GENERIC_IOMAP wrapper
Hi Arnd,
On Sat, Mar 15, 2025 at 11:59:06AM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann
>
> All PIO on MIPS platforms is memory mapped, so there is no benefit in
> the lib/iomap.c wrappers that switch between inb/outb and readb/writeb
> style accessses.
>
> In fact, the '#define PIO_RESERVED 0' setting completely disables
> the GENERIC_IOMAP functionality, and the '#define PIO_OFFSET
> mips_io_port_base' setting is based on a misunderstanding of what the
> offset is meant to do.
>
> MIPS started using GENERIC_IOMAP in 2018 with commit b962aeb02205 ("MIPS:
> Use GENERIC_IOMAP") replacing a simple custom implementation of the same
> interfaces, but at the time the asm-generic/io.h version was not usable
> yet. Since the header is now always included, it's now possible to go
> back to the even simpler version.
>
> Use the normal GENERIC_PCI_IOMAP functionality for all mips platforms
> without the hacky GENERIC_IOMAP, and provide a custom pci_iounmap()
> for the CONFIG_PCI_DRIVERS_LEGACY case to ensure the I/O port base never
> gets unmapped.
>
> The readsl() prototype needs an extra 'const' keyword to make it
> compatible with the generic ioread32_rep() alias.
>
> Signed-off-by: Arnd Bergmann
> ---
> arch/mips/Kconfig | 2 +-
> arch/mips/include/asm/io.h | 21 -
> arch/mips/lib/iomap-pci.c | 9 +
> 3 files changed, 18 insertions(+), 14 deletions(-)
>
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index 1924f2d83932..2a2120a6d852 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -38,7 +38,6 @@ config MIPS
> select GENERIC_CMOS_UPDATE
> select GENERIC_CPU_AUTOPROBE
> select GENERIC_GETTIMEOFDAY
> - select GENERIC_IOMAP
> select GENERIC_IRQ_PROBE
> select GENERIC_IRQ_SHOW
> select GENERIC_ISA_DMA if EISA
> @@ -47,6 +46,7 @@ config MIPS
> select GENERIC_LIB_CMPDI2
> select GENERIC_LIB_LSHRDI3
> select GENERIC_LIB_UCMPDI2
> + select GENERIC_PCI_IOMAP
> select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
> select GENERIC_SMP_IDLE_THREAD
> select GENERIC_IDLE_POLL_SETUP
> diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
> index 0bddb568af7c..1fe56d1870a6 100644
> --- a/arch/mips/include/asm/io.h
> +++ b/arch/mips/include/asm/io.h
> @@ -66,17 +66,6 @@ static inline void set_io_port_base(unsigned long base)
> mips_io_port_base = base;
> }
>
> -/*
> - * Provide the necessary definitions for generic iomap. We make use of
> - * mips_io_port_base for iomap(), but we don't reserve any low addresses for
> - * use with I/O ports.
> - */
> -
> -#define HAVE_ARCH_PIO_SIZE
> -#define PIO_OFFSET mips_io_port_base
> -#define PIO_MASK IO_SPACE_LIMIT
> -#define PIO_RESERVED 0x0UL
> -
> /*
> * Enforce in-order execution of data I/O. In the MIPS architecture
> * these are equivalent to corresponding platform-specific memory
> @@ -397,8 +386,8 @@ static inline void writes##bwlq(volatile void __iomem
> *mem, \
> } \
> }\
> \
> -static inline void reads##bwlq(volatile void __iomem *mem, void *addr,
> \
> -unsigned int count) \
> +static inline void reads##bwlq(const volatile void __iomem *mem, \
> +void *addr, unsigned int count) \
> {\
> volatile type *__addr = addr; \
> \
> @@ -555,6 +544,12 @@ extern void (*_dma_cache_inv)(unsigned long start,
> unsigned long size);
>
> void __ioread64_copy(void *to, const void __iomem *from, size_t count);
>
> +#ifdef CONFIG_PCI_DRIVERS_LEGACY
> +struct pci_dev;
> +void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
> +#define pci_iounmap pci_iounmap
> +#endif
> +
> #include
>
> static inline void *isa_bus_to_virt(unsigned long address)
> diff --git a/arch/mips/lib/iomap-pci.c b/arch/mips/lib/iomap-pci.c
> index a9cb28813f0b..2f82c776c6d0 100644
> --- a/arch/mips/lib/iomap-pci.c
> +++ b/arch/mips/lib/iomap-pci.c
> @@ -43,4 +43,13 @@ void __iomem *__pci_ioport_map(struct pci_dev *dev,
> return (void __iomem *) (ctrl->io_map_base + port);
> }
>
> +void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
> +{
> + struct pci_controller *ctrl = dev->bus->sysdata;
> + void __iomem *base = (void __iomem *)ctrl->io_map_base;
> +
> + if (addr < base || addr > (base + resource_size(ctrl->io_resource)))
> + iounmap(addr);
> +}
> +
> #endif /* CONFIG_PCI_DRIVERS_LEGACY */
> --
> 2.39.5
>
This change as commit 976bf3aec388 ("mips: drop GENERIC_IOMAP wrapper") in
-next introdu
[PATCH 5/6] mips: drop GENERIC_IOMAP wrapper
From: Arnd Bergmann
All PIO on MIPS platforms is memory mapped, so there is no benefit in
the lib/iomap.c wrappers that switch between inb/outb and readb/writeb
style accessses.
In fact, the '#define PIO_RESERVED 0' setting completely disables
the GENERIC_IOMAP functionality, and the '#define PIO_OFFSET
mips_io_port_base' setting is based on a misunderstanding of what the
offset is meant to do.
MIPS started using GENERIC_IOMAP in 2018 with commit b962aeb02205 ("MIPS:
Use GENERIC_IOMAP") replacing a simple custom implementation of the same
interfaces, but at the time the asm-generic/io.h version was not usable
yet. Since the header is now always included, it's now possible to go
back to the even simpler version.
Use the normal GENERIC_PCI_IOMAP functionality for all mips platforms
without the hacky GENERIC_IOMAP, and provide a custom pci_iounmap()
for the CONFIG_PCI_DRIVERS_LEGACY case to ensure the I/O port base never
gets unmapped.
The readsl() prototype needs an extra 'const' keyword to make it
compatible with the generic ioread32_rep() alias.
Signed-off-by: Arnd Bergmann
---
arch/mips/Kconfig | 2 +-
arch/mips/include/asm/io.h | 21 -
arch/mips/lib/iomap-pci.c | 9 +
3 files changed, 18 insertions(+), 14 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 1924f2d83932..2a2120a6d852 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -38,7 +38,6 @@ config MIPS
select GENERIC_CMOS_UPDATE
select GENERIC_CPU_AUTOPROBE
select GENERIC_GETTIMEOFDAY
- select GENERIC_IOMAP
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
select GENERIC_ISA_DMA if EISA
@@ -47,6 +46,7 @@ config MIPS
select GENERIC_LIB_CMPDI2
select GENERIC_LIB_LSHRDI3
select GENERIC_LIB_UCMPDI2
+ select GENERIC_PCI_IOMAP
select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
select GENERIC_SMP_IDLE_THREAD
select GENERIC_IDLE_POLL_SETUP
diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 0bddb568af7c..1fe56d1870a6 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -66,17 +66,6 @@ static inline void set_io_port_base(unsigned long base)
mips_io_port_base = base;
}
-/*
- * Provide the necessary definitions for generic iomap. We make use of
- * mips_io_port_base for iomap(), but we don't reserve any low addresses for
- * use with I/O ports.
- */
-
-#define HAVE_ARCH_PIO_SIZE
-#define PIO_OFFSET mips_io_port_base
-#define PIO_MASK IO_SPACE_LIMIT
-#define PIO_RESERVED 0x0UL
-
/*
* Enforce in-order execution of data I/O. In the MIPS architecture
* these are equivalent to corresponding platform-specific memory
@@ -397,8 +386,8 @@ static inline void writes##bwlq(volatile void __iomem *mem,
\
} \
} \
\
-static inline void reads##bwlq(volatile void __iomem *mem, void *addr, \
- unsigned int count) \
+static inline void reads##bwlq(const volatile void __iomem *mem, \
+ void *addr, unsigned int count) \
{ \
volatile type *__addr = addr; \
\
@@ -555,6 +544,12 @@ extern void (*_dma_cache_inv)(unsigned long start,
unsigned long size);
void __ioread64_copy(void *to, const void __iomem *from, size_t count);
+#ifdef CONFIG_PCI_DRIVERS_LEGACY
+struct pci_dev;
+void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
+#define pci_iounmap pci_iounmap
+#endif
+
#include
static inline void *isa_bus_to_virt(unsigned long address)
diff --git a/arch/mips/lib/iomap-pci.c b/arch/mips/lib/iomap-pci.c
index a9cb28813f0b..2f82c776c6d0 100644
--- a/arch/mips/lib/iomap-pci.c
+++ b/arch/mips/lib/iomap-pci.c
@@ -43,4 +43,13 @@ void __iomem *__pci_ioport_map(struct pci_dev *dev,
return (void __iomem *) (ctrl->io_map_base + port);
}
+void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
+{
+ struct pci_controller *ctrl = dev->bus->sysdata;
+ void __iomem *base = (void __iomem *)ctrl->io_map_base;
+
+ if (addr < base || addr > (base + resource_size(ctrl->io_resource)))
+ iounmap(addr);
+}
+
#endif /* CONFIG_PCI_DRIVERS_LEGACY */
--
2.39.5
