Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1668366

Re: [RFC PATCH 06/13] switchtec_ntb: initialize hardware for memory windows

Show all headers | View raw

On 16/06/17 11:16 PM, Greg Kroah-Hartman wrote:
>> +#ifndef ioread64
>> +#ifdef readq
>> +#define ioread64 readq
>> +#else
>> +#define ioread64 _ioread64
>> +static inline u64 _ioread64(void __iomem *mmio)
>> +{
>> +	u64 low, high;
>> +
>> +	low = ioread32(mmio);
>> +	high = ioread32(mmio + sizeof(u32));
>> +	return low | (high << 32);
>> +}
>> +#endif
>> +#endif
> 
> Really?  Don't we have ioread64 in generic code for all arches?  If not,
> that should be fixed, don't hide this in a random driver please.  Or
> just restrict your driver to only building on those arches that does
> provide this api.

Yes, I know these are _very_ ugly. Unfortunately, the other ntb drivers
each have the exact same thing. ioread64 is not provided universally at
this time and I did spend a bit of time digging and things are a bit
messy so I wasn't at all sure of the correct solution.

For starters, ioread64 is only defined on 64 bit machines. They are
surrounded by ifdef CONFIG_64BIT and it's not clear to me if the above
wrapper (around two ioread32s) would be acceptable universally.

Second, the x86_64 version doesn't even compile. This is because the
arch doesn't provide any ioread64 implementation anywhere and the macro
in io.h isn't used because CONFIG_GENERIC_IOMAP is defined.

The only arch where I _think_ ioread64 would work is powerpc or any that
define CONFIG_64BIT and not CONFIG_GENERIC_IOMAP.

If you have any guidance on this I'd be happy to try and make a patch or
two for it.

Thanks,

Logan

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[RFC PATCH 00/13] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-06-15 22:40 +0200
  [RFC PATCH 09/13] switchtec_ntb: add link management Logan Gunthorpe <logang@deltatee.com> - 2017-06-15 22:40 +0200
  [RFC PATCH 04/13] switchtec: add link event notifier block Logan Gunthorpe <logang@deltatee.com> - 2017-06-15 22:40 +0200
    Re: [RFC PATCH 04/13] switchtec: add link event notifier block Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-17 07:20 +0200
      Re: [RFC PATCH 04/13] switchtec: add link event notifier block Logan Gunthorpe <logang@deltatee.com> - 2017-06-17 18:30 +0200
  [RFC PATCH 06/13] switchtec_ntb: initialize hardware for memory windows Logan Gunthorpe <logang@deltatee.com> - 2017-06-15 22:50 +0200
    Re: [RFC PATCH 06/13] switchtec_ntb: initialize hardware for memory  windows Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-17 07:20 +0200
      Re: [RFC PATCH 06/13] switchtec_ntb: initialize hardware for memory  windows Logan Gunthorpe <logang@deltatee.com> - 2017-06-17 18:40 +0200
        Re: [RFC PATCH 06/13] switchtec_ntb: initialize hardware for memory  windows Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-18 02:40 +0200
  [RFC PATCH 13/13] switchtec_ntb: update switchtec documentation with notes for ntb Logan Gunthorpe <logang@deltatee.com> - 2017-06-15 22:50 +0200
  [RFC PATCH 02/13] switchtec: export class symbol for use in upper layer driver Logan Gunthorpe <logang@deltatee.com> - 2017-06-15 22:50 +0200
    Re: [RFC PATCH 02/13] switchtec: export class symbol for use in  upper layer driver Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-06-17 07:20 +0200
      Re: [RFC PATCH 02/13] switchtec: export class symbol for use in upper  layer driver Logan Gunthorpe <logang@deltatee.com> - 2017-06-17 18:20 +0200
  [RFC PATCH 08/13] switchtec_ntb: add skeleton ntb driver Logan Gunthorpe <logang@deltatee.com> - 2017-06-15 22:50 +0200
  [RFC PATCH 05/13] switchtec_ntb: introduce initial ntb driver Logan Gunthorpe <logang@deltatee.com> - 2017-06-15 22:50 +0200
  RE: [RFC PATCH 00/13] Switchtec NTB Support "Allen Hubbe" <Allen.Hubbe@dell.com> - 2017-06-16 16:00 +0200
    Re: [RFC PATCH 00/13] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-06-16 16:20 +0200
      RE: [RFC PATCH 00/13] Switchtec NTB Support "Allen Hubbe" <Allen.Hubbe@dell.com> - 2017-06-16 17:40 +0200
        Re: [RFC PATCH 00/13] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-06-16 18:50 +0200
          Re: [RFC PATCH 00/13] Switchtec NTB Support Serge Semin <fancer.lancer@gmail.com> - 2017-06-16 19:40 +0200
          RE: [RFC PATCH 00/13] Switchtec NTB Support "Allen Hubbe" <Allen.Hubbe@dell.com> - 2017-06-16 20:10 +0200
            Re: [RFC PATCH 00/13] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-06-16 21:20 +0200
      Re: [RFC PATCH 00/13] Switchtec NTB Support Serge Semin <fancer.lancer@gmail.com> - 2017-06-16 18:40 +0200
        Re: [RFC PATCH 00/13] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-06-16 19:10 +0200
          Re: [RFC PATCH 00/13] Switchtec NTB Support Serge Semin <fancer.lancer@gmail.com> - 2017-06-16 20:40 +0200
            Re: [RFC PATCH 00/13] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-06-16 21:40 +0200
              Re: [RFC PATCH 00/13] Switchtec NTB Support Serge Semin <fancer.lancer@gmail.com> - 2017-06-16 22:30 +0200
                Re: [RFC PATCH 00/13] Switchtec NTB Support 'Greg Kroah-Hartman' <gregkh@linuxfoundation.org> - 2017-06-17 07:20 +0200
                Re: [RFC PATCH 00/13] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-06-17 18:20 +0200
                Re: [RFC PATCH 00/13] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-06-17 18:20 +0200
                Re: [RFC PATCH 00/13] Switchtec NTB Support Jon Mason <jdmason@kudzu.us> - 2017-06-19 21:20 +0200
  Re: [RFC PATCH 00/13] Switchtec NTB Support Jon Mason <jdmason@kudzu.us> - 2017-06-19 22:10 +0200
    Re: [RFC PATCH 00/13] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-06-19 22:30 +0200
      Re: [RFC PATCH 00/13] Switchtec NTB Support Jon Mason <jdmason@kudzu.us> - 2017-06-19 23:10 +0200

csiph-web