Re: [PATCH] PCI/sysfs: Use correct variable for the legacy_mem sysfs object

[Bjorn Helgaas <helgaas@kernel.org>]

[+to Greg, please update sysfs_defferred_iomem_get_mapping-5.15]

On Thu, Aug 12, 2021 at 01:21:44PM +0000, Krzysztof Wilczyński wrote:
> Two legacy PCI sysfs objects "legacy_io" and "legacy_mem" were updated
> to use an unified address space in the commit 636b21b50152 ("PCI: Revoke
> mappings like devmem").  This allows for revocations to be managed from
> a single place when drivers want to take over and mmap() a /dev/mem
> range.
> 
> Following the update, both of the sysfs objects should leverage the
> iomem_get_mapping() function to get an appropriate address range, but
> only the "legacy_io" has been correctly updated - the second attribute
> seems to be using a wrong variable to pass the iomem_get_mapping()
> function to.
> 
> Thus, correct the variable name used so that the "legacy_mem" sysfs
> object would also correctly call the iomem_get_mapping() function.
> 
> Fixes: 636b21b50152 ("PCI: Revoke mappings like devmem")
> Signed-off-by: Krzysztof Wilczyński <kw@linux.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

Ouch.  This needs to be applied to any -stable trees that contain
636b21b50152, which was merged in v5.12.

It *also* needs to be applied with the obvious updates to Greg's
sysfs_defferred_iomem_get_mapping-5.15 branch because it was changed
by f06aff924f97 ("sysfs: Rename struct bin_attribute member to
f_mapping") [1]

[1] https://git.kernel.org/cgit/linux/kernel/git/gregkh/driver-core.git/commit/?id=f06aff924f97

> ---
>  drivers/pci/pci-sysfs.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index 5d63df7c1820..7bbf2673c7f2 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -978,7 +978,7 @@ void pci_create_legacy_files(struct pci_bus *b)
>  	b->legacy_mem->size = 1024*1024;
>  	b->legacy_mem->attr.mode = 0600;
>  	b->legacy_mem->mmap = pci_mmap_legacy_mem;
> -	b->legacy_io->mapping = iomem_get_mapping();
> +	b->legacy_mem->mapping = iomem_get_mapping();
>  	pci_adjust_legacy_attr(b, pci_mmap_mem);
>  	error = device_create_bin_file(&b->dev, b->legacy_mem);
>  	if (error)
> -- 
> 2.32.0
>