Re: [Qemu-devel] [SeaBIOS] [PATCH v4 2/3] target-i386: reserve RCRB mmio space in ACPI DSDT table

[Paolo Bonzini <pbonzini@redhat.com>]

----- Original Message -----
> From: "Igor Mammedov" <imammedo@redhat.com>
> To: "Paulo Alcantara" <pcacjr@gmail.com>
> Cc: qemu-devel@nongnu.org, pbonzini@redhat.com, seabios@seabios.org, mst@redhat.com
> Sent: Tuesday, June 23, 2015 12:38:59 PM
> Subject: Re: [SeaBIOS] [PATCH v4 2/3] target-i386: reserve RCRB mmio space in ACPI DSDT table
> 
> On Sun, 21 Jun 2015 21:37:02 -0300
> Paulo Alcantara <pcacjr@gmail.com> wrote:
> 
> > This block is mapped into memory space, using the Root Complex Base
> > Address (RCBA) register of the PCI-to-LPC bridge. Accesses in this space
> > must be limited to 32-(DW) bit quantities. Burst accesses are not
> > allowed.
> > 
> > All Chipset Configuration Registers are located in this 16KiB space.
> > 
> > Signed-off-by: Paulo Alcantara <pcacjr@zytor.com>
> > ---
> > v1 -> v2:
> >   * s/PDRC/CCR/ for clarity and match ICH9 spec
> >   * remove unnecessary OperationRegion for RCRB
> > 
> > v2 -> v3: (no changes)
> > 
> > v3 -> v4:
> >   * quote RCRB description from ICH9 spec to commit log
> >   * fix indentation issue in _CRS() method declaration
> >   * create hw/i386/ich9-cc.h for chipset configuration register values
> >     and use them in ASL
> > ---
> >  hw/i386/q35-acpi-dsdt.dsl     |  16 ++++++++++++++++
> >  include/hw/i386/ich9-cc.h     |  31 +++++++++++++++++++++++++++++++
> >  tests/acpi-test-data/q35/DSDT | Bin 7666 -> 7723 bytes
> >  3 files changed, 47 insertions(+)
> >  create mode 100644 include/hw/i386/ich9-cc.h
> > 
> > diff --git a/hw/i386/q35-acpi-dsdt.dsl b/hw/i386/q35-acpi-dsdt.dsl
> > index 16eaca3..512c220 100644
> > --- a/hw/i386/q35-acpi-dsdt.dsl
> > +++ b/hw/i386/q35-acpi-dsdt.dsl
> > @@ -114,6 +114,22 @@ DefinitionBlock (
> >          }
> >      }
> >  
> > +#include "hw/i386/ich9-cc.h"
> > +
> > +/****************************************************************
> > + * Chipset Configuration Registers
> > + ****************************************************************/
> > +Scope(\_SB.PCI0) {
> > +    Device (CCR) {
> I'd name it something like: TCOW
> 
> > +        Name (_HID, EISAID("PNP0C02"))
> PNP0C02 not in ACPI spec, pls use PNP0A06 like we do in other places
> for reserving IO space.

The ACPI spec says "Note: Plug and Play IDs that are not defined by the ACPI
specification are defined and described in the following document [URL]"
where PNP0C02 is the "General ID for reserving resources required by Plug
and Play system board registers (not specific to a particular device)".

PNP0A06 is the "ACPI bus", whatever that means.

Paolo

> > +        Name (_UID, 1)
> s/1/"TCO watchdog resources"/
> > +
> > +        Name (_CRS, ResourceTemplate() {
> > +            Memory32Fixed(ReadWrite, RCBA_BASE_ADDR, RCRB_SIZE)
> since this values are dynamically programmed by BIOS
> it's incorrect to put them here statically.
> Take RCBA_BASE_ADDR from respective ICH9 register,
> which should be programmed by BIOS before ACPI tables are read by it.
> 
> Also like Michael suggested create this device dynamically in build_ssdt(),
> for example look at "if (misc->applesmc_io_base) {" block in
> hw/i386/acpi-build.c and add this device only if it's present
> (i.e. for version from which it's supported)
> 
> > +        })
> > +    }
> > +}
> > +
> >  #include "acpi-dsdt-hpet.dsl"
> >  
> >  
> > diff --git a/include/hw/i386/ich9-cc.h b/include/hw/i386/ich9-cc.h
> > new file mode 100644
> > index 0000000..675fb7f
> > --- /dev/null
> > +++ b/include/hw/i386/ich9-cc.h
> > @@ -0,0 +1,31 @@
> > +/*
> > + * QEMU ICH9 Chipset Configuration Registers
> > + *
> > + * Copyright (c) 2015 Paulo Alcantara <pcacjr@zytor.com>
> > + *
> > + * Permission is hereby granted, free of charge, to any person obtaining a
> > copy
> > + * of this software and associated documentation files (the "Software"),
> > to deal
> > + * in the Software without restriction, including without limitation the
> > rights
> > + * to use, copy, modify, merge, publish, distribute, sublicense, and/or
> > sell
> > + * copies of the Software, and to permit persons to whom the Software is
> > + * furnished to do so, subject to the following conditions:
> > + *
> > + * The above copyright notice and this permission notice shall be included
> > in
> > + * all copies or substantial portions of the Software.
> > + *
> > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
> > OR
> > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> > MERCHANTABILITY,
> > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
> > OTHER
> > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> > FROM,
> > + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> > IN
> > + * THE SOFTWARE.
> > + */
> > +
> > +#ifndef HW_ICH9_CC_H
> > +#define HW_ICH9_CC_H
> > +
> > +#define RCBA_BASE_ADDR    0xfed1c000
> where does this value come from?
> 
> > +#define RCRB_SIZE         0x00004000
> > +
> > +#endif /* HW_ICH9_CC_H */
> > diff --git a/tests/acpi-test-data/q35/DSDT b/tests/acpi-test-data/q35/DSDT
> > index
> > 4723e5954dccb00995ccaf521b7daf6bf15cf1d4..f3bda7b54ea6d669b1498d9380e7781207fb6e49
> > 100644
> > GIT binary patch
> > delta 81
> > zcmexlz1oJ$CD<iITaJN&F>xbTJfnq$UVN}qe1Nm3L3ERjvvW{9N4$rp3y<Rk9wv_X
> > lP)`>|j(F#wU_n7HzBWz<Mur0y|1mf)FjO*Z&S3140RVI`6(s-w
> > 
> > delta 24
> > gcmZ2&^U0daCD<k8lPm)R<DrdQ@r;`nF?PxT0Bl$YHUIzs
> > 
> 
>