| Message ID | 20210822161005.22467-3-sergio.paracuellos@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | MIPS: ralink: properly handle pci IO resources | expand |
On Sun, Aug 22, 2021 at 6:10 PM Sergio Paracuellos <sergio.paracuellos@gmail.com> wrote: > > Request for I/O resources from device tree call 'pci_remap_iospace' from > 'devm_pci_remap_iospace' which is also called from device tree function > 'pci_parse_request_of_pci_ranges'. if PCI_IOBASE is not defined and I/O > resources are requested the following warning appears: > > ------------[ cut here ]------------ > WARNING: CPU: 2 PID: 1 at ../drivers/pci/pci.c:4066 pci_remap_iospace+0x3c/0x54 > This architecture does not support memory mapped I/O > Modules linked in: > CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.10.1+ #1228 > Stack : 00000000 00000000 807fa974 00000000 827ffa80 80066b48 80710000 0000000b > 00000000 00000000 81c59aac 7d06ddec 80850000 00000001 81c59a40 7d06ddec > 00000000 00000000 807c909c 81c598f0 00000001 81c59904 00000000 0000000a > 203a6d6d 80708880 0000000f 70617773 80850000 00000000 00000000 807d0000 > 807ffecc 1e160000 00000001 00000200 00000000 8054e920 00000008 815e0008 > ... > Call Trace: > [<80008efc>] show_stack+0x8c/0x130 > [<806e1674>] dump_stack+0x9c/0xc8 > [<80024a3c>] __warn+0xc0/0xe8 > [<80024ad0>] warn_slowpath_fmt+0x6c/0xbc > [<80410ca8>] pci_remap_iospace+0x3c/0x54 > [<80410d20>] devm_pci_remap_iospace+0x58/0xa4 > [<8042019c>] devm_of_pci_bridge_init+0x4dc/0x55c > [<80408de8>] devm_pci_alloc_host_bridge+0x78/0x88 > [<80424e44>] mt7621_pci_probe+0x68/0x9a4 > [<80464804>] platform_drv_probe+0x40/0x7c > [<804628bc>] really_probe+0x2fc/0x4e4 > [<80463214>] device_driver_attach+0x4c/0x74 > [<80463384>] __driver_attach+0x148/0x150 > [<8046047c>] bus_for_each_dev+0x6c/0xb0 > [<804614dc>] bus_add_driver+0x1b4/0x1fc > [<80463aa0>] driver_register+0xd0/0x110 > [<80001714>] do_one_initcall+0x84/0x1c0 > [<808e7fd0>] kernel_init_freeable+0x214/0x24c > [<806e4164>] kernel_init+0x14/0x118 > [<80003358>] ret_from_kernel_thread+0x14/0x1c > > ---[ end trace 1c9d4412bd51b53c ]--- > mt7621-pci 1e140000.pcie: error -19: failed to map resource [io 0x1e160000-0x1e16ffff] > > Since there are architectures (like MIPS ralink) that can request I/O > resources from device tree but have not mapeable I/O space and also PCI_IOBASE > not defined, avoid this warning and just return zero to make the I/O ranges > assignment work. > > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> > --- > drivers/pci/pci.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) Hi Bjorn, Any comments on this patch? Are you ok with this one also going through the staging tree like the other two patches in the series? Thanks in advance for your time. Best regards, Sergio Paracuellos > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index aacf575c15cf..10bb2191f376 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4102,9 +4102,9 @@ unsigned long __weak pci_address_to_pio(phys_addr_t address) > * @phys_addr: physical address of range to be mapped > * > * Remap the memory mapped I/O space described by the @res and the CPU > - * physical address @phys_addr into virtual address space. Only > - * architectures that have memory mapped IO functions defined (and the > - * PCI_IOBASE value defined) should call this function. > + * physical address @phys_addr into virtual address space. There > + * are architectures that don't define PCI_IOBASE but can have not > + * mapeable IO space. Return zero for those cases. > */ > int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) > { > @@ -4122,10 +4122,10 @@ int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) > #else > /* > * This architecture does not have memory mapped I/O space, > - * so this function should never be called > + * but can have not mapeable I/O space, so just return ok > + * here. > */ > - WARN_ONCE(1, "This architecture does not support memory mapped I/O\n"); > - return -ENODEV; > + return 0; > #endif > } > EXPORT_SYMBOL(pci_remap_iospace); > -- > 2.25.1 >
[+cc Liviu, Rob, Catalin, Arnd, since this warning was added by
8b921acfeffd ("PCI: Add pci_remap_iospace() to map bus I/O resources"),
https://git.kernel.org/linus/8b921acfeffd]
On Sun, Aug 22, 2021 at 06:10:04PM +0200, Sergio Paracuellos wrote:
> Request for I/O resources from device tree call 'pci_remap_iospace' from
> 'devm_pci_remap_iospace' which is also called from device tree function
> 'pci_parse_request_of_pci_ranges'. if PCI_IOBASE is not defined and I/O
> resources are requested the following warning appears:
>
> ------------[ cut here ]------------
> WARNING: CPU: 2 PID: 1 at ../drivers/pci/pci.c:4066 pci_remap_iospace+0x3c/0x54
> This architecture does not support memory mapped I/O
> Modules linked in:
> CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.10.1+ #1228
> Stack : 00000000 00000000 807fa974 00000000 827ffa80 80066b48 80710000 0000000b
> 00000000 00000000 81c59aac 7d06ddec 80850000 00000001 81c59a40 7d06ddec
> 00000000 00000000 807c909c 81c598f0 00000001 81c59904 00000000 0000000a
> 203a6d6d 80708880 0000000f 70617773 80850000 00000000 00000000 807d0000
> 807ffecc 1e160000 00000001 00000200 00000000 8054e920 00000008 815e0008
> ...
> Call Trace:
> [<80008efc>] show_stack+0x8c/0x130
> [<806e1674>] dump_stack+0x9c/0xc8
> [<80024a3c>] __warn+0xc0/0xe8
> [<80024ad0>] warn_slowpath_fmt+0x6c/0xbc
> [<80410ca8>] pci_remap_iospace+0x3c/0x54
> [<80410d20>] devm_pci_remap_iospace+0x58/0xa4
> [<8042019c>] devm_of_pci_bridge_init+0x4dc/0x55c
> [<80408de8>] devm_pci_alloc_host_bridge+0x78/0x88
> [<80424e44>] mt7621_pci_probe+0x68/0x9a4
> [<80464804>] platform_drv_probe+0x40/0x7c
> [<804628bc>] really_probe+0x2fc/0x4e4
> [<80463214>] device_driver_attach+0x4c/0x74
> [<80463384>] __driver_attach+0x148/0x150
> [<8046047c>] bus_for_each_dev+0x6c/0xb0
> [<804614dc>] bus_add_driver+0x1b4/0x1fc
> [<80463aa0>] driver_register+0xd0/0x110
> [<80001714>] do_one_initcall+0x84/0x1c0
> [<808e7fd0>] kernel_init_freeable+0x214/0x24c
> [<806e4164>] kernel_init+0x14/0x118
> [<80003358>] ret_from_kernel_thread+0x14/0x1c
>
> ---[ end trace 1c9d4412bd51b53c ]---
> mt7621-pci 1e140000.pcie: error -19: failed to map resource [io 0x1e160000-0x1e16ffff]
>
> Since there are architectures (like MIPS ralink) that can request I/O
> resources from device tree but have not mapeable I/O space and also PCI_IOBASE
> not defined, avoid this warning and just return zero to make the I/O ranges
> assignment work.
>
> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
> ---
> drivers/pci/pci.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index aacf575c15cf..10bb2191f376 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -4102,9 +4102,9 @@ unsigned long __weak pci_address_to_pio(phys_addr_t address)
> * @phys_addr: physical address of range to be mapped
> *
> * Remap the memory mapped I/O space described by the @res and the CPU
> - * physical address @phys_addr into virtual address space. Only
> - * architectures that have memory mapped IO functions defined (and the
> - * PCI_IOBASE value defined) should call this function.
> + * physical address @phys_addr into virtual address space. There
> + * are architectures that don't define PCI_IOBASE but can have not
> + * mapeable IO space. Return zero for those cases.
> */
> int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
> {
> @@ -4122,10 +4122,10 @@ int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
> #else
> /*
> * This architecture does not have memory mapped I/O space,
> - * so this function should never be called
> + * but can have not mapeable I/O space, so just return ok
> + * here.
> */
> - WARN_ONCE(1, "This architecture does not support memory mapped I/O\n");
> - return -ENODEV;
> + return 0;
This doesn't seem right to me. pci_remap_iospace() remaps
memory-mapped I/O space into virtual address space.
If the architecture doesn't support that remapping, we shouldn't claim
that it succeeded.
The analogous path for ACPI is in acpi_pci_root_remap_iospace(), where
we only call pci_remap_iospace() if PCI_IOBASE is defined. Maybe we
should use the same approach here, i.e., add the corresonding #ifdef
in pci_parse_request_of_pci_ranges()?
> #endif
> }
> EXPORT_SYMBOL(pci_remap_iospace);
> --
> 2.25.1
>
Hi Bjorn, On Tue, Sep 21, 2021 at 7:49 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > [+cc Liviu, Rob, Catalin, Arnd, since this warning was added by > 8b921acfeffd ("PCI: Add pci_remap_iospace() to map bus I/O resources"), > https://git.kernel.org/linus/8b921acfeffd] > > On Sun, Aug 22, 2021 at 06:10:04PM +0200, Sergio Paracuellos wrote: > > Request for I/O resources from device tree call 'pci_remap_iospace' from > > 'devm_pci_remap_iospace' which is also called from device tree function > > 'pci_parse_request_of_pci_ranges'. if PCI_IOBASE is not defined and I/O > > resources are requested the following warning appears: > > > > ------------[ cut here ]------------ > > WARNING: CPU: 2 PID: 1 at ../drivers/pci/pci.c:4066 pci_remap_iospace+0x3c/0x54 > > This architecture does not support memory mapped I/O > > Modules linked in: > > CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.10.1+ #1228 > > Stack : 00000000 00000000 807fa974 00000000 827ffa80 80066b48 80710000 0000000b > > 00000000 00000000 81c59aac 7d06ddec 80850000 00000001 81c59a40 7d06ddec > > 00000000 00000000 807c909c 81c598f0 00000001 81c59904 00000000 0000000a > > 203a6d6d 80708880 0000000f 70617773 80850000 00000000 00000000 807d0000 > > 807ffecc 1e160000 00000001 00000200 00000000 8054e920 00000008 815e0008 > > ... > > Call Trace: > > [<80008efc>] show_stack+0x8c/0x130 > > [<806e1674>] dump_stack+0x9c/0xc8 > > [<80024a3c>] __warn+0xc0/0xe8 > > [<80024ad0>] warn_slowpath_fmt+0x6c/0xbc > > [<80410ca8>] pci_remap_iospace+0x3c/0x54 > > [<80410d20>] devm_pci_remap_iospace+0x58/0xa4 > > [<8042019c>] devm_of_pci_bridge_init+0x4dc/0x55c > > [<80408de8>] devm_pci_alloc_host_bridge+0x78/0x88 > > [<80424e44>] mt7621_pci_probe+0x68/0x9a4 > > [<80464804>] platform_drv_probe+0x40/0x7c > > [<804628bc>] really_probe+0x2fc/0x4e4 > > [<80463214>] device_driver_attach+0x4c/0x74 > > [<80463384>] __driver_attach+0x148/0x150 > > [<8046047c>] bus_for_each_dev+0x6c/0xb0 > > [<804614dc>] bus_add_driver+0x1b4/0x1fc > > [<80463aa0>] driver_register+0xd0/0x110 > > [<80001714>] do_one_initcall+0x84/0x1c0 > > [<808e7fd0>] kernel_init_freeable+0x214/0x24c > > [<806e4164>] kernel_init+0x14/0x118 > > [<80003358>] ret_from_kernel_thread+0x14/0x1c > > > > ---[ end trace 1c9d4412bd51b53c ]--- > > mt7621-pci 1e140000.pcie: error -19: failed to map resource [io 0x1e160000-0x1e16ffff] > > > > Since there are architectures (like MIPS ralink) that can request I/O > > resources from device tree but have not mapeable I/O space and also PCI_IOBASE > > not defined, avoid this warning and just return zero to make the I/O ranges > > assignment work. > > > > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> > > --- > > drivers/pci/pci.c | 12 ++++++------ > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > index aacf575c15cf..10bb2191f376 100644 > > --- a/drivers/pci/pci.c > > +++ b/drivers/pci/pci.c > > @@ -4102,9 +4102,9 @@ unsigned long __weak pci_address_to_pio(phys_addr_t address) > > * @phys_addr: physical address of range to be mapped > > * > > * Remap the memory mapped I/O space described by the @res and the CPU > > - * physical address @phys_addr into virtual address space. Only > > - * architectures that have memory mapped IO functions defined (and the > > - * PCI_IOBASE value defined) should call this function. > > + * physical address @phys_addr into virtual address space. There > > + * are architectures that don't define PCI_IOBASE but can have not > > + * mapeable IO space. Return zero for those cases. > > */ > > int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) > > { > > @@ -4122,10 +4122,10 @@ int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) > > #else > > /* > > * This architecture does not have memory mapped I/O space, > > - * so this function should never be called > > + * but can have not mapeable I/O space, so just return ok > > + * here. > > */ > > - WARN_ONCE(1, "This architecture does not support memory mapped I/O\n"); > > - return -ENODEV; > > + return 0; > > This doesn't seem right to me. pci_remap_iospace() remaps > memory-mapped I/O space into virtual address space. > > If the architecture doesn't support that remapping, we shouldn't claim > that it succeeded. > > The analogous path for ACPI is in acpi_pci_root_remap_iospace(), where > we only call pci_remap_iospace() if PCI_IOBASE is defined. Maybe we > should use the same approach here, i.e., add the corresonding #ifdef > in pci_parse_request_of_pci_ranges()? This approach you are talking here is what I did in v1 of this series [0] and you tell me to properly fix that in the 'pci_remap_iospace'. Both of these v1 and v2 obviously end up in a working pci system for mt7621 ralink. Another option I guess would be to mark 'pci_remap_iospace' as weak and redefine the symbol for ralink but since it is only for one simple return zero maybe it makes no sense at all... Please, tell me the correct approach to properly fix this and make things work for this platform. Thanks in advance for your time, Sergio Paracuellos [0]: https://lore.kernel.org/linux-pci/20210807072409.9018-2-sergio.paracuellos@gmail.com/T/#m73c19c3b72fdf8c63e6d3fe8dc80aeee4e4adcaa > > > #endif > > } > > EXPORT_SYMBOL(pci_remap_iospace); > > -- > > 2.25.1 > >
If you repost this, please update the subject line like: PCI: of: Avoid pci_remap_iospace() when PCI_IOBASE not defined On Tue, Sep 21, 2021 at 08:36:07PM +0200, Sergio Paracuellos wrote: > On Tue, Sep 21, 2021 at 7:49 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > > > [+cc Liviu, Rob, Catalin, Arnd, since this warning was added by > > 8b921acfeffd ("PCI: Add pci_remap_iospace() to map bus I/O resources"), > > https://git.kernel.org/linus/8b921acfeffd] > > > > On Sun, Aug 22, 2021 at 06:10:04PM +0200, Sergio Paracuellos wrote: > > > Request for I/O resources from device tree call 'pci_remap_iospace' from > > > 'devm_pci_remap_iospace' which is also called from device tree function > > > 'pci_parse_request_of_pci_ranges'. if PCI_IOBASE is not defined and I/O > > > resources are requested the following warning appears: s/'pci_remap_iospace'/pci_remap_iospace()/ s/'devm_pci_remap_iospace'/devm_pci_remap_iospace()/ s/'pci_parse_request_of_pci_ranges'/pci_parse_request_of_pci_ranges()/ s/if PCI_IOBASE/If PCI_IOBASE/ I think you can trim the stacktrace below and keep just this: WARNING: CPU: 2 PID: 1 at ../drivers/pci/pci.c:4066 pci_remap_iospace+0x3c/0x54 This architecture does not support memory mapped I/O mt7621-pci 1e140000.pcie: error -19: failed to map resource [io 0x1e160000-0x1e16ffff] > > > > > > ------------[ cut here ]------------ > > > WARNING: CPU: 2 PID: 1 at ../drivers/pci/pci.c:4066 pci_remap_iospace+0x3c/0x54 > > > This architecture does not support memory mapped I/O > > > Modules linked in: > > > CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.10.1+ #1228 > > > Stack : 00000000 00000000 807fa974 00000000 827ffa80 80066b48 80710000 0000000b > > > 00000000 00000000 81c59aac 7d06ddec 80850000 00000001 81c59a40 7d06ddec > > > 00000000 00000000 807c909c 81c598f0 00000001 81c59904 00000000 0000000a > > > 203a6d6d 80708880 0000000f 70617773 80850000 00000000 00000000 807d0000 > > > 807ffecc 1e160000 00000001 00000200 00000000 8054e920 00000008 815e0008 > > > ... > > > Call Trace: > > > [<80008efc>] show_stack+0x8c/0x130 > > > [<806e1674>] dump_stack+0x9c/0xc8 > > > [<80024a3c>] __warn+0xc0/0xe8 > > > [<80024ad0>] warn_slowpath_fmt+0x6c/0xbc > > > [<80410ca8>] pci_remap_iospace+0x3c/0x54 > > > [<80410d20>] devm_pci_remap_iospace+0x58/0xa4 > > > [<8042019c>] devm_of_pci_bridge_init+0x4dc/0x55c > > > [<80408de8>] devm_pci_alloc_host_bridge+0x78/0x88 > > > [<80424e44>] mt7621_pci_probe+0x68/0x9a4 > > > [<80464804>] platform_drv_probe+0x40/0x7c > > > [<804628bc>] really_probe+0x2fc/0x4e4 > > > [<80463214>] device_driver_attach+0x4c/0x74 > > > [<80463384>] __driver_attach+0x148/0x150 > > > [<8046047c>] bus_for_each_dev+0x6c/0xb0 > > > [<804614dc>] bus_add_driver+0x1b4/0x1fc > > > [<80463aa0>] driver_register+0xd0/0x110 > > > [<80001714>] do_one_initcall+0x84/0x1c0 > > > [<808e7fd0>] kernel_init_freeable+0x214/0x24c > > > [<806e4164>] kernel_init+0x14/0x118 > > > [<80003358>] ret_from_kernel_thread+0x14/0x1c > > > > > > ---[ end trace 1c9d4412bd51b53c ]--- > > > mt7621-pci 1e140000.pcie: error -19: failed to map resource [io 0x1e160000-0x1e16ffff] > > > > > > Since there are architectures (like MIPS ralink) that can request I/O > > > resources from device tree but have not mapeable I/O space and also PCI_IOBASE > > > not defined, avoid this warning and just return zero to make the I/O ranges > > > assignment work. s/have not mapeable I/O space and also PCI_IOBASE not defined/ don't have mappable I/O space and therefore don't define PCI_IOBASE/ s/avoid this warning .../ avoid calling devm_pci_remap_iospace() in that case/ > > > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> > > > --- > > > drivers/pci/pci.c | 12 ++++++------ > > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > index aacf575c15cf..10bb2191f376 100644 > > > --- a/drivers/pci/pci.c > > > +++ b/drivers/pci/pci.c > > > @@ -4102,9 +4102,9 @@ unsigned long __weak pci_address_to_pio(phys_addr_t address) > > > * @phys_addr: physical address of range to be mapped > > > * > > > * Remap the memory mapped I/O space described by the @res and the CPU > > > - * physical address @phys_addr into virtual address space. Only > > > - * architectures that have memory mapped IO functions defined (and the > > > - * PCI_IOBASE value defined) should call this function. > > > + * physical address @phys_addr into virtual address space. There > > > + * are architectures that don't define PCI_IOBASE but can have not > > > + * mapeable IO space. Return zero for those cases. > > > */ > > > int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) > > > { > > > @@ -4122,10 +4122,10 @@ int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) > > > #else > > > /* > > > * This architecture does not have memory mapped I/O space, > > > - * so this function should never be called > > > + * but can have not mapeable I/O space, so just return ok > > > + * here. > > > */ > > > - WARN_ONCE(1, "This architecture does not support memory mapped I/O\n"); > > > - return -ENODEV; > > > + return 0; > > > > This doesn't seem right to me. pci_remap_iospace() remaps > > memory-mapped I/O space into virtual address space. > > > > If the architecture doesn't support that remapping, we shouldn't claim > > that it succeeded. > > > > The analogous path for ACPI is in acpi_pci_root_remap_iospace(), where > > we only call pci_remap_iospace() if PCI_IOBASE is defined. Maybe we > > should use the same approach here, i.e., add the corresonding #ifdef > > in pci_parse_request_of_pci_ranges()? > > This approach you are talking here is what I did in v1 of this series > [0] and you tell me to properly fix that in the 'pci_remap_iospace'. Hmm, sorry, you're absolutely right. I guess I was thinking that pci_remap_iospace() was broken because it returns -ENODEV when the arch can't remap I/O port space into virtual memory space. But that doesn't seem right. If the arch literally cannot do that remapping, why should pci_remap_iospace() return success and basically pretend that it can? And the acpi_pci_root_remap_iospace() case is doing exactly the same thing, and we live with the #ifdef there. So I think I was just wrong before, and we should make the DT case similar by adding the #ifdef where you initially put it, in pci_parse_request_of_pci_ranges(). > Both of these v1 and v2 obviously end up in a working pci system for > mt7621 ralink. > Another option I guess would be to mark 'pci_remap_iospace' as weak > and redefine the symbol for ralink but since it is only for one simple > return zero maybe it makes no sense at all... Please, tell me the > correct approach to properly fix this and make things work for this > platform. Making pci_remap_iospace() weak could work (and I think it was originally that way), but seems overkill to me, unless you want a way to make generic mips kernels that work both on ralink and other mips platforms. > Thanks in advance for your time, > Sergio Paracuellos > > [0]: https://lore.kernel.org/linux-pci/20210807072409.9018-2-sergio.paracuellos@gmail.com/T/#m73c19c3b72fdf8c63e6d3fe8dc80aeee4e4adcaa > > > > > > #endif > > > } > > > EXPORT_SYMBOL(pci_remap_iospace); > > > -- > > > 2.25.1 > > >
Hi Bjorn, On Tue, Sep 21, 2021 at 9:38 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > If you repost this, please update the subject line like: > > PCI: of: Avoid pci_remap_iospace() when PCI_IOBASE not defined > > On Tue, Sep 21, 2021 at 08:36:07PM +0200, Sergio Paracuellos wrote: > > On Tue, Sep 21, 2021 at 7:49 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > > > > > [+cc Liviu, Rob, Catalin, Arnd, since this warning was added by > > > 8b921acfeffd ("PCI: Add pci_remap_iospace() to map bus I/O resources"), > > > https://git.kernel.org/linus/8b921acfeffd] > > > > > > On Sun, Aug 22, 2021 at 06:10:04PM +0200, Sergio Paracuellos wrote: > > > > Request for I/O resources from device tree call 'pci_remap_iospace' from > > > > 'devm_pci_remap_iospace' which is also called from device tree function > > > > 'pci_parse_request_of_pci_ranges'. if PCI_IOBASE is not defined and I/O > > > > resources are requested the following warning appears: > > s/'pci_remap_iospace'/pci_remap_iospace()/ > s/'devm_pci_remap_iospace'/devm_pci_remap_iospace()/ > s/'pci_parse_request_of_pci_ranges'/pci_parse_request_of_pci_ranges()/ > s/if PCI_IOBASE/If PCI_IOBASE/ > > I think you can trim the stacktrace below and keep just this: > > WARNING: CPU: 2 PID: 1 at ../drivers/pci/pci.c:4066 pci_remap_iospace+0x3c/0x54 > This architecture does not support memory mapped I/O > mt7621-pci 1e140000.pcie: error -19: failed to map resource [io 0x1e160000-0x1e16ffff] > > > > > > > > > ------------[ cut here ]------------ > > > > WARNING: CPU: 2 PID: 1 at ../drivers/pci/pci.c:4066 pci_remap_iospace+0x3c/0x54 > > > > This architecture does not support memory mapped I/O > > > > Modules linked in: > > > > CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.10.1+ #1228 > > > > Stack : 00000000 00000000 807fa974 00000000 827ffa80 80066b48 80710000 0000000b > > > > 00000000 00000000 81c59aac 7d06ddec 80850000 00000001 81c59a40 7d06ddec > > > > 00000000 00000000 807c909c 81c598f0 00000001 81c59904 00000000 0000000a > > > > 203a6d6d 80708880 0000000f 70617773 80850000 00000000 00000000 807d0000 > > > > 807ffecc 1e160000 00000001 00000200 00000000 8054e920 00000008 815e0008 > > > > ... > > > > Call Trace: > > > > [<80008efc>] show_stack+0x8c/0x130 > > > > [<806e1674>] dump_stack+0x9c/0xc8 > > > > [<80024a3c>] __warn+0xc0/0xe8 > > > > [<80024ad0>] warn_slowpath_fmt+0x6c/0xbc > > > > [<80410ca8>] pci_remap_iospace+0x3c/0x54 > > > > [<80410d20>] devm_pci_remap_iospace+0x58/0xa4 > > > > [<8042019c>] devm_of_pci_bridge_init+0x4dc/0x55c > > > > [<80408de8>] devm_pci_alloc_host_bridge+0x78/0x88 > > > > [<80424e44>] mt7621_pci_probe+0x68/0x9a4 > > > > [<80464804>] platform_drv_probe+0x40/0x7c > > > > [<804628bc>] really_probe+0x2fc/0x4e4 > > > > [<80463214>] device_driver_attach+0x4c/0x74 > > > > [<80463384>] __driver_attach+0x148/0x150 > > > > [<8046047c>] bus_for_each_dev+0x6c/0xb0 > > > > [<804614dc>] bus_add_driver+0x1b4/0x1fc > > > > [<80463aa0>] driver_register+0xd0/0x110 > > > > [<80001714>] do_one_initcall+0x84/0x1c0 > > > > [<808e7fd0>] kernel_init_freeable+0x214/0x24c > > > > [<806e4164>] kernel_init+0x14/0x118 > > > > [<80003358>] ret_from_kernel_thread+0x14/0x1c > > > > > > > > ---[ end trace 1c9d4412bd51b53c ]--- > > > > mt7621-pci 1e140000.pcie: error -19: failed to map resource [io 0x1e160000-0x1e16ffff] > > > > > > > > Since there are architectures (like MIPS ralink) that can request I/O > > > > resources from device tree but have not mapeable I/O space and also PCI_IOBASE > > > > not defined, avoid this warning and just return zero to make the I/O ranges > > > > assignment work. > > s/have not mapeable I/O space and also PCI_IOBASE not defined/ > don't have mappable I/O space and therefore don't define PCI_IOBASE/ > s/avoid this warning .../ > avoid calling devm_pci_remap_iospace() in that case/ > > > > > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> > > > > --- > > > > drivers/pci/pci.c | 12 ++++++------ > > > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > index aacf575c15cf..10bb2191f376 100644 > > > > --- a/drivers/pci/pci.c > > > > +++ b/drivers/pci/pci.c > > > > @@ -4102,9 +4102,9 @@ unsigned long __weak pci_address_to_pio(phys_addr_t address) > > > > * @phys_addr: physical address of range to be mapped > > > > * > > > > * Remap the memory mapped I/O space described by the @res and the CPU > > > > - * physical address @phys_addr into virtual address space. Only > > > > - * architectures that have memory mapped IO functions defined (and the > > > > - * PCI_IOBASE value defined) should call this function. > > > > + * physical address @phys_addr into virtual address space. There > > > > + * are architectures that don't define PCI_IOBASE but can have not > > > > + * mapeable IO space. Return zero for those cases. > > > > */ > > > > int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) > > > > { > > > > @@ -4122,10 +4122,10 @@ int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) > > > > #else > > > > /* > > > > * This architecture does not have memory mapped I/O space, > > > > - * so this function should never be called > > > > + * but can have not mapeable I/O space, so just return ok > > > > + * here. > > > > */ > > > > - WARN_ONCE(1, "This architecture does not support memory mapped I/O\n"); > > > > - return -ENODEV; > > > > + return 0; > > > > > > This doesn't seem right to me. pci_remap_iospace() remaps > > > memory-mapped I/O space into virtual address space. > > > > > > If the architecture doesn't support that remapping, we shouldn't claim > > > that it succeeded. > > > > > > The analogous path for ACPI is in acpi_pci_root_remap_iospace(), where > > > we only call pci_remap_iospace() if PCI_IOBASE is defined. Maybe we > > > should use the same approach here, i.e., add the corresonding #ifdef > > > in pci_parse_request_of_pci_ranges()? > > > > This approach you are talking here is what I did in v1 of this series > > [0] and you tell me to properly fix that in the 'pci_remap_iospace'. > I have already send v3 of ths patch with all the changes in commit message and description that you are pointing out here, thanks: https://lore.kernel.org/linux-pci/20210922042041.16326-1-sergio.paracuellos@gmail.com/T/#u > Hmm, sorry, you're absolutely right. > > I guess I was thinking that pci_remap_iospace() was broken because it > returns -ENODEV when the arch can't remap I/O port space into virtual > memory space. But that doesn't seem right. If the arch literally > cannot do that remapping, why should pci_remap_iospace() return > success and basically pretend that it can? No problem at all :). I also should have asked a bit more about why to fix things there since I thought initially it seemed to not be the right thing to do. > > And the acpi_pci_root_remap_iospace() case is doing exactly the same > thing, and we live with the #ifdef there. So I think I was just wrong > before, and we should make the DT case similar by adding the #ifdef > where you initially put it, in pci_parse_request_of_pci_ranges(). > > > Both of these v1 and v2 obviously end up in a working pci system for > > mt7621 ralink. > > Another option I guess would be to mark 'pci_remap_iospace' as weak > > and redefine the symbol for ralink but since it is only for one simple > > return zero maybe it makes no sense at all... Please, tell me the > > correct approach to properly fix this and make things work for this > > platform. > > Making pci_remap_iospace() weak could work (and I think it was > originally that way), but seems overkill to me, unless you want a way > to make generic mips kernels that work both on ralink and other mips > platforms. That is not the case and agree with you that seems overkill. Thanks in advance for your time. Best regards, Sergio Paracuellos > > > Thanks in advance for your time, > > Sergio Paracuellos > > > > [0]: https://lore.kernel.org/linux-pci/20210807072409.9018-2-sergio.paracuellos@gmail.com/T/#m73c19c3b72fdf8c63e6d3fe8dc80aeee4e4adcaa > > > > > > > > > #endif > > > > } > > > > EXPORT_SYMBOL(pci_remap_iospace); > > > > -- > > > > 2.25.1 > > > >
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index aacf575c15cf..10bb2191f376 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4102,9 +4102,9 @@ unsigned long __weak pci_address_to_pio(phys_addr_t address) * @phys_addr: physical address of range to be mapped * * Remap the memory mapped I/O space described by the @res and the CPU - * physical address @phys_addr into virtual address space. Only - * architectures that have memory mapped IO functions defined (and the - * PCI_IOBASE value defined) should call this function. + * physical address @phys_addr into virtual address space. There + * are architectures that don't define PCI_IOBASE but can have not + * mapeable IO space. Return zero for those cases. */ int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) { @@ -4122,10 +4122,10 @@ int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) #else /* * This architecture does not have memory mapped I/O space, - * so this function should never be called + * but can have not mapeable I/O space, so just return ok + * here. */ - WARN_ONCE(1, "This architecture does not support memory mapped I/O\n"); - return -ENODEV; + return 0; #endif } EXPORT_SYMBOL(pci_remap_iospace);
Request for I/O resources from device tree call 'pci_remap_iospace' from 'devm_pci_remap_iospace' which is also called from device tree function 'pci_parse_request_of_pci_ranges'. if PCI_IOBASE is not defined and I/O resources are requested the following warning appears: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1 at ../drivers/pci/pci.c:4066 pci_remap_iospace+0x3c/0x54 This architecture does not support memory mapped I/O Modules linked in: CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.10.1+ #1228 Stack : 00000000 00000000 807fa974 00000000 827ffa80 80066b48 80710000 0000000b 00000000 00000000 81c59aac 7d06ddec 80850000 00000001 81c59a40 7d06ddec 00000000 00000000 807c909c 81c598f0 00000001 81c59904 00000000 0000000a 203a6d6d 80708880 0000000f 70617773 80850000 00000000 00000000 807d0000 807ffecc 1e160000 00000001 00000200 00000000 8054e920 00000008 815e0008 ... Call Trace: [<80008efc>] show_stack+0x8c/0x130 [<806e1674>] dump_stack+0x9c/0xc8 [<80024a3c>] __warn+0xc0/0xe8 [<80024ad0>] warn_slowpath_fmt+0x6c/0xbc [<80410ca8>] pci_remap_iospace+0x3c/0x54 [<80410d20>] devm_pci_remap_iospace+0x58/0xa4 [<8042019c>] devm_of_pci_bridge_init+0x4dc/0x55c [<80408de8>] devm_pci_alloc_host_bridge+0x78/0x88 [<80424e44>] mt7621_pci_probe+0x68/0x9a4 [<80464804>] platform_drv_probe+0x40/0x7c [<804628bc>] really_probe+0x2fc/0x4e4 [<80463214>] device_driver_attach+0x4c/0x74 [<80463384>] __driver_attach+0x148/0x150 [<8046047c>] bus_for_each_dev+0x6c/0xb0 [<804614dc>] bus_add_driver+0x1b4/0x1fc [<80463aa0>] driver_register+0xd0/0x110 [<80001714>] do_one_initcall+0x84/0x1c0 [<808e7fd0>] kernel_init_freeable+0x214/0x24c [<806e4164>] kernel_init+0x14/0x118 [<80003358>] ret_from_kernel_thread+0x14/0x1c ---[ end trace 1c9d4412bd51b53c ]--- mt7621-pci 1e140000.pcie: error -19: failed to map resource [io 0x1e160000-0x1e16ffff] Since there are architectures (like MIPS ralink) that can request I/O resources from device tree but have not mapeable I/O space and also PCI_IOBASE not defined, avoid this warning and just return zero to make the I/O ranges assignment work. Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> --- drivers/pci/pci.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)