diff mbox series

[6/6] m68k/nommu: stop using GENERIC_IOMAP

Message ID 20250315105907.1275012-7-arnd@kernel.org (mailing list archive)
State New
Headers show
Series asm-generic: io.h cleanups | expand

Commit Message

Arnd Bergmann March 15, 2025, 10:59 a.m. UTC
From: Arnd Bergmann <arnd@arndb.de>

There is no need to go through the GENERIC_IOMAP wrapper for PIO on
nommu platforms, since these always come from PCI I/O space that is
itself memory mapped.

Instead, the generic ioport_map() can just return the MMIO location
of the ports directly by applying the PCI_IO_PA offset, while
ioread32/iowrite32 trivially turn into readl/writel as they do
on most other architectures.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/m68k/Kconfig             | 2 +-
 arch/m68k/include/asm/io_no.h | 4 ----
 2 files changed, 1 insertion(+), 5 deletions(-)

Comments

Greg Ungerer March 24, 2025, 1:33 a.m. UTC | #1
Hi Arnd,

On 15/3/25 20:59, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> There is no need to go through the GENERIC_IOMAP wrapper for PIO on
> nommu platforms, since these always come from PCI I/O space that is
> itself memory mapped.
> 
> Instead, the generic ioport_map() can just return the MMIO location
> of the ports directly by applying the PCI_IO_PA offset, while
> ioread32/iowrite32 trivially turn into readl/writel as they do
> on most other architectures.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

With this applied this fails to build for me:

   UPD     include/generated/utsversion.h
   CC      init/version-timestamp.o
   LD      vmlinux
m68k-linux-uclibc-ld: drivers/pci/quirks.o: in function `quirk_switchtec_ntb_dma_alias':
quirks.c:(.text+0x23e4): undefined reference to `pci_iomap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x24fe): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: drivers/pci/quirks.o: in function `disable_igfx_irq':
quirks.c:(.text+0x32f4): undefined reference to `pci_iomap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x3348): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x338a): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x33d2): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: drivers/pci/quirks.o: in function `reset_ivb_igd':
quirks.c:(.text+0x3502): undefined reference to `pci_iomap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x3658): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x3682): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: drivers/pci/quirks.o: in function `reset_hinic_vf_dev':
quirks.c:(.text+0x3844): undefined reference to `pci_iomap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x39fc): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x3a86): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x3ab4): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: drivers/pci/quirks.o: in function `quirk_reset_lenovo_thinkpad_p50_nvgpu':
quirks.c:(.text+0x3cf6): undefined reference to `pci_iomap'
m68k-linux-uclibc-ld: drivers/pci/quirks.o: in function `nvme_disable_and_flr':
quirks.c:(.text+0x3e32): undefined reference to `pci_iomap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x3eac): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: quirks.c:(.text+0x3fc0): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: drivers/pci/devres.o: in function `pcim_addr_resource_release':
devres.c:(.text+0x414): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: devres.c:(.text+0x420): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: drivers/pci/devres.o: in function `pcim_iomap':
devres.c:(.text+0x524): undefined reference to `pci_iomap'
m68k-linux-uclibc-ld: devres.c:(.text+0x576): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: drivers/pci/devres.o: in function `pcim_iomap_range':
devres.c:(.text+0x980): undefined reference to `pci_iomap_range'
m68k-linux-uclibc-ld: drivers/pci/devres.o: in function `pcim_iomap_region':
devres.c:(.text+0xc0e): undefined reference to `pci_iomap'
m68k-linux-uclibc-ld: drivers/net/ethernet/intel/e100.o: in function `e100_remove':
e100.c:(.text+0x1fe6): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: drivers/net/ethernet/intel/e100.o: in function `e100_probe':
e100.c:(.text+0x362a): undefined reference to `pci_iomap'
m68k-linux-uclibc-ld: e100.c:(.text+0x381c): undefined reference to `pci_iounmap'
m68k-linux-uclibc-ld: e100.c:(.text+0x3928): undefined reference to `pci_iounmap'
make[2]: *** [scripts/Makefile.vmlinux:77: vmlinux] Error 1
make[1]: *** [/home/gerg/accelerated-linux.lkml/linux/Makefile:1231: vmlinux] Error 2
make: *** [Makefile:251: __sub-make] Error 2

FWIW this was a m5475evb_defconfig with CONFIG_MMU disabled.

Regards
Greg



> ---
>   arch/m68k/Kconfig             | 2 +-
>   arch/m68k/include/asm/io_no.h | 4 ----
>   2 files changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
> index b2ed0308c0ea..b50c275fa94d 100644
> --- a/arch/m68k/Kconfig
> +++ b/arch/m68k/Kconfig
> @@ -18,7 +18,7 @@ config M68K
>   	select DMA_DIRECT_REMAP if M68K_NONCOHERENT_DMA && !COLDFIRE
>   	select GENERIC_ATOMIC64
>   	select GENERIC_CPU_DEVICES
> -	select GENERIC_IOMAP if HAS_IOPORT
> +	select GENERIC_IOMAP if HAS_IOPORT && MMU
>   	select GENERIC_IRQ_SHOW
>   	select GENERIC_LIB_ASHLDI3
>   	select GENERIC_LIB_ASHRDI3
> diff --git a/arch/m68k/include/asm/io_no.h b/arch/m68k/include/asm/io_no.h
> index 2c96e8480173..516371d5587a 100644
> --- a/arch/m68k/include/asm/io_no.h
> +++ b/arch/m68k/include/asm/io_no.h
> @@ -123,10 +123,6 @@ static inline void writel(u32 value, volatile void __iomem *addr)
>   #define PCI_IO_SIZE	0x00010000		/* 64k */
>   #define PCI_IO_MASK	(PCI_IO_SIZE - 1)
>   
> -#define HAVE_ARCH_PIO_SIZE
> -#define PIO_OFFSET	0
> -#define PIO_MASK	0xffff
> -#define PIO_RESERVED	0x10000
>   #define PCI_IOBASE	((void __iomem *) PCI_IO_PA)
>   #define PCI_SPACE_LIMIT	PCI_IO_MASK
>   #endif /* CONFIG_PCI */
Arnd Bergmann March 24, 2025, 8:02 a.m. UTC | #2
On Mon, Mar 24, 2025, at 02:33, Greg Ungerer wrote:
> Hi Arnd,
>
> On 15/3/25 20:59, Arnd Bergmann wrote:
>> From: Arnd Bergmann <arnd@arndb.de>
>> 
>> There is no need to go through the GENERIC_IOMAP wrapper for PIO on
>> nommu platforms, since these always come from PCI I/O space that is
>> itself memory mapped.
>> 
>> Instead, the generic ioport_map() can just return the MMIO location
>> of the ports directly by applying the PCI_IO_PA offset, while
>> ioread32/iowrite32 trivially turn into readl/writel as they do
>> on most other architectures.
>> 
>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>
> With this applied this fails to build for me:
>
>    UPD     include/generated/utsversion.h
>    CC      init/version-timestamp.o
>    LD      vmlinux
> m68k-linux-uclibc-ld: drivers/pci/quirks.o: in function 
> `quirk_switchtec_ntb_dma_alias':
> quirks.c:(.text+0x23e4): undefined reference to `pci_iomap'
> m68k-linux-uclibc-ld: quirks.c:(.text+0x24fe): undefined reference to 
> `pci_iounmap'
> m68k-linux-uclibc-ld: drivers/pci/quirks.o: in function 
> `disable_igfx_irq':
> quirks.c:(.text+0x32f4): undefined reference to `pci_iomap'
> m68k-linux-uclibc-ld: quirks.c:(.text+0x3348): undefined reference to 
> `pci_iounmap'

Thanks for the report, I was able to reproduce the problem now
and applied the fixup below. I had tested m5475evb_defconfig earlier,
and that built cleanly with PCI enabled, but I had missed how
that still used GENERIC_IOMAP because it has CONFIG_MMU enabled.

Does this fixup work for you?

On a related note, I'm curious about how the MCF54xx chips are
used in practice, as I see that they are the only coldfire chips
with PCI and they all have an MMU. Are there actual users of these
chips that have PCI but choose not to use the MMU? 

      Arnd

8<-----
From a36995e2a64711556c6773797367d165828f6705 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Mon, 24 Mar 2025 07:53:47 +0100
Subject: [PATCH] m68k: coldfire: select PCI_IOMAP for PCI

After I dropped CONFIG_GENERIC_IOMAP, some PCI drivers started failing
to link when CONFIG_MMU is disabled:

ERROR: modpost: "pci_iounmap" [drivers/video/fbdev/i740fb.ko] undefined!
ERROR: modpost: "pci_iounmap" [drivers/video/fbdev/vt8623fb.ko] undefined!
ERROR: modpost: "pci_iomap_wc" [drivers/video/fbdev/vt8623fb.ko] undefined!
ERROR: modpost: "pci_iomap" [drivers/video/fbdev/vt8623fb.ko] undefined!
ERROR: modpost: "pci_iounmap" [drivers/video/fbdev/s3fb.ko] undefined!
...

It turns out that there were two mistakes in my patch: on !MMU I forgot
to enable CONFIG_GENERIC_PCI_IOMAP, and for Coldfire with MMU enabled,
teh GENERIC_IOMAP was left in place but incorrectly configured.

Fixes: 9d48cc07d0d7 ("m68k/nommu: stop using GENERIC_IOMAP")
Reported-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index b50c275fa94d..eb5bb6d36899 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -18,12 +18,13 @@ config M68K
 	select DMA_DIRECT_REMAP if M68K_NONCOHERENT_DMA && !COLDFIRE
 	select GENERIC_ATOMIC64
 	select GENERIC_CPU_DEVICES
-	select GENERIC_IOMAP if HAS_IOPORT && MMU
+	select GENERIC_IOMAP if HAS_IOPORT && MMU && !COLDFIRE
 	select GENERIC_IRQ_SHOW
 	select GENERIC_LIB_ASHLDI3
 	select GENERIC_LIB_ASHRDI3
 	select GENERIC_LIB_LSHRDI3
 	select GENERIC_LIB_MULDI3
+	select GENERIC_PCI_IOMAP if PCI
 	select HAS_IOPORT if PCI || ISA || ATARI_ROM_ISA
 	select HAVE_ARCH_LIBGCC_H
 	select HAVE_ARCH_SECCOMP
diff mbox series

Patch

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index b2ed0308c0ea..b50c275fa94d 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -18,7 +18,7 @@  config M68K
 	select DMA_DIRECT_REMAP if M68K_NONCOHERENT_DMA && !COLDFIRE
 	select GENERIC_ATOMIC64
 	select GENERIC_CPU_DEVICES
-	select GENERIC_IOMAP if HAS_IOPORT
+	select GENERIC_IOMAP if HAS_IOPORT && MMU
 	select GENERIC_IRQ_SHOW
 	select GENERIC_LIB_ASHLDI3
 	select GENERIC_LIB_ASHRDI3
diff --git a/arch/m68k/include/asm/io_no.h b/arch/m68k/include/asm/io_no.h
index 2c96e8480173..516371d5587a 100644
--- a/arch/m68k/include/asm/io_no.h
+++ b/arch/m68k/include/asm/io_no.h
@@ -123,10 +123,6 @@  static inline void writel(u32 value, volatile void __iomem *addr)
 #define PCI_IO_SIZE	0x00010000		/* 64k */
 #define PCI_IO_MASK	(PCI_IO_SIZE - 1)
 
-#define HAVE_ARCH_PIO_SIZE
-#define PIO_OFFSET	0
-#define PIO_MASK	0xffff
-#define PIO_RESERVED	0x10000
 #define PCI_IOBASE	((void __iomem *) PCI_IO_PA)
 #define PCI_SPACE_LIMIT	PCI_IO_MASK
 #endif /* CONFIG_PCI */