Re: [edk2-devel] Additional configuration options on Armada/Cn913x

["Marcin Wojtas" <mw@semihalf.com>]

pt., 12 cze 2020 o 18:32 myfreeweb <greg@unrelenting.technology> napisał(a):
>
>
>
> On June 12, 2020 3:07:21 PM UTC, Marcin Wojtas <mw@semihalf.com> wrote:
> >Hi,
> >
> >I see Greg was dropped in the meantime.
> >
> >pt., 12 cze 2020 o 10:45 Ard Biesheuvel <ard.biesheuvel@arm.com> napisał(a):
> >>
> >> On 6/12/20 12:43 AM, Mark Kettenis via Groups.Io wrote:
> >> > On Thu, Jun 11, 2020 at 04:17 PM, Ard Biesheuvel wrote:
> >> >
> >> >     On 6/11/20 4:07 PM, greg@unrelenting.technology wrote:
> >> >
> >> >         June 11, 2020 4:19 PM, "Ard Biesheuvel" <ard.biesheuvel@arm.com>
> >> >         wrote:
> >> >
> >> >             On 6/5/20 5:19 PM, Marcin Wojtas via groups.io wrote:
> >> >
> >> >                 Hi,
> >> >                 I'd like to ask for comments before I develop the actual
> >> >                 code - > currently we have 2 workarounds
> >> >                 done specifically for Linux:
> >> >                 a. ECAM shift in PCIE
> >> >                 b. SPCR address space definition
> >> >
> >> >             What does this mean?
> >> >
> >> >         The SPCR in upstream edk2 is set up to work around some Linux
> >> >         weirdness (?) and I have to do this:
> >> >
> >> >         https://github.com/myfreeweb/edk2-platforms/commit/74ec98a6498e78d2ae6c861db88487bf75f2e1a1
> >> >
> >> >         to make it work on FreeBSD.
> >> >
> >> >     Surely, they can't both be correct. Marcin?
> >> >
> >> > Assuming the serial port on Armada/Cn911x is the same as on Armada8k,
> >> > the following DT properties would be applicable:
> >> >
> >> > reg-shift = <2>;
> >> > reg-io-width = <1>
> >> >
> >> > which means the registers are spaced 32-bits apart but have to be
> >> > accessed using 8-bit load/store instructions.  I'd say that
> >> > means that the ACPI Generic Address Space should have RegisterBitWidth
> >> > set to 32 and AccessSize set to BYTE.
> >> > In other words, I think that the current:
> >> >
> >> > #define MV_UART_AS32(Address) { EFI_ACPI_5_0_SYSTEM_MEMORY, 32, 0,
> >> > EFI_ACPI_5_0_BYTE, Address }
> >> >
> >> > is correct.  That certainly is what works for OpenBSD.
> >>
> >> Thanks Mark
> >>
> >> The struct type is defined as
> >>
> >> typedef struct {
> >>    UINT8   AddressSpaceId;
> >>    UINT8   RegisterBitWidth;
> >>    UINT8   RegisterBitOffset;
> >>    UINT8   AccessSize;
> >>    UINT64  Address;
> >> } EFI_ACPI_5_0_GENERIC_ADDRESS_STRUCTURE;
> >>
> >> so I agree that the current definition matches a UART that requires byte
> >> accesses on registers that are 32 bits apart.
> >>
> >> So why does FreeBSD deviate from this?
> >
> >Greg, can you please explain your concerns here?
>
> Yeah, looking at our code again, looks like we did screw it up, seems like we are using register width as access width and vice versa :/

Ok, so I'll prepare only a switch to toggle the ECAM hack enablement.

Any chance you submit a fix to phabricator?

Best regards,
Marcin