| Message ID | 1539182575-26851-1-git-send-email-wesley.sheng@microchip.com |
|---|---|
| State | Accepted |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | [v3] NTB: switchtec_ntb: Update switchtec documentation with pre-requisites for NTB | expand |
On 2018-10-10 8:42 a.m., Wesley Sheng wrote: > From: Wesley Yung <wesley.yung@microchip.com> > > The ntb_hw_switchtec driver has requirements on kernel configuration > so we add these notes to the documentation and also clean up a few > other sentences in the documentation. > > Signed-off-by: Wesley Yung <wesley.yung@microchip.com> > Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com> > Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
[+cc Jon Mason] On Wed, Oct 10, 2018 at 10:42:55PM +0800, Wesley Sheng wrote: > From: Wesley Yung <wesley.yung@microchip.com> > > The ntb_hw_switchtec driver has requirements on kernel configuration > so we add these notes to the documentation and also clean up a few > other sentences in the documentation. > > Signed-off-by: Wesley Yung <wesley.yung@microchip.com> > Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com> > Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com> I'm not sure who should really own this file: $ ./scripts/get_maintainer.pl -f Documentation/switchtec.txt Kurt Schwemmer <kurt.schwemmer@microsemi.com> (maintainer:PCI DRIVER FOR MICROSEMI SWITCHTEC) Logan Gunthorpe <logang@deltatee.com> (maintainer:PCI DRIVER FOR MICROSEMI SWITCHTEC) Jonathan Corbet <corbet@lwn.net> (maintainer:DOCUMENTATION) linux-pci@vger.kernel.org (open list:PCI DRIVER FOR MICROSEMI SWITCHTEC) linux-doc@vger.kernel.org (open list:DOCUMENTATION) linux-kernel@vger.kernel.org (open list) and Jon (NTB driver core maintainer) has applied recent updates to it. But in the interest of forward progress, I applied this patch with Logan's ack to pci/misc for v4.20. > --- > Documentation/switchtec.txt | 30 ++++++++++++++++++++---------- > 1 file changed, 20 insertions(+), 10 deletions(-) > > diff --git a/Documentation/switchtec.txt b/Documentation/switchtec.txt > index f788264..d6f04dcc 100644 > --- a/Documentation/switchtec.txt > +++ b/Documentation/switchtec.txt > @@ -23,7 +23,7 @@ The primary means of communicating with the Switchtec management firmware is > through the Memory-mapped Remote Procedure Call (MRPC) interface. > Commands are submitted to the interface with a 4-byte command > identifier and up to 1KB of command specific data. The firmware will > -respond with a 4 bytes return code and up to 1KB of command specific > +respond with a 4-byte return code and up to 1KB of command specific > data. The interface only processes a single command at a time. > > > @@ -36,8 +36,8 @@ device: /dev/switchtec#, one for each management endpoint in the system. > The char device has the following semantics: > > * A write must consist of at least 4 bytes and no more than 1028 bytes. > - The first four bytes will be interpreted as the command to run and > - the remainder will be used as the input data. A write will send the > + The first 4 bytes will be interpreted as the Command ID and the > + remainder will be used as the input data. A write will send the > command to the firmware to begin processing. > > * Each write must be followed by exactly one read. Any double write will > @@ -45,9 +45,9 @@ The char device has the following semantics: > produce an error. > > * A read will block until the firmware completes the command and return > - the four bytes of status plus up to 1024 bytes of output data. (The > - length will be specified by the size parameter of the read call -- > - reading less than 4 bytes will produce an error. > + the 4-byte Command Return Value plus up to 1024 bytes of output > + data. (The length will be specified by the size parameter of the read > + call -- reading less than 4 bytes will produce an error.) > > * The poll call will also be supported for userspace applications that > need to do other things while waiting for the command to complete. > @@ -83,10 +83,20 @@ The following IOCTLs are also supported by the device: > Non-Transparent Bridge (NTB) Driver > =================================== > > -An NTB driver is provided for the switchtec hardware in switchtec_ntb. > -Currently, it only supports switches configured with exactly 2 > -partitions. It also requires the following configuration settings: > +An NTB hardware driver is provided for the Switchtec hardware in > +ntb_hw_switchtec. Currently, it only supports switches configured with > +exactly 2 NT partitions and zero or more non-NT partitions. It also requires > +the following configuration settings: > > -* Both partitions must be able to access each other's GAS spaces. > +* Both NT partitions must be able to access each other's GAS spaces. > Thus, the bits in the GAS Access Vector under Management Settings > must be set to support this. > +* Kernel configuration MUST include support for NTB (CONFIG_NTB needs > + to be set) > + > +NT EP BAR 2 will be dynamically configured as a Direct Window, and > +the configuration file does not need to configure it explicitly. > + > +Please refer to Documentation/ntb.txt in Linux source tree for an overall > +understanding of the Linux NTB stack. ntb_hw_switchtec works as an NTB > +Hardware Driver in this stack. > -- > 2.7.4 >
On 2018-10-11 10:27 a.m., Bjorn Helgaas wrote: > I'm not sure who should really own this file: > > $ ./scripts/get_maintainer.pl -f Documentation/switchtec.txt > Kurt Schwemmer <kurt.schwemmer@microsemi.com> (maintainer:PCI DRIVER FOR MICROSEMI SWITCHTEC) > Logan Gunthorpe <logang@deltatee.com> (maintainer:PCI DRIVER FOR MICROSEMI SWITCHTEC) > Jonathan Corbet <corbet@lwn.net> (maintainer:DOCUMENTATION) > linux-pci@vger.kernel.org (open list:PCI DRIVER FOR MICROSEMI SWITCHTEC) > linux-doc@vger.kernel.org (open list:DOCUMENTATION) > linux-kernel@vger.kernel.org (open list) > > and Jon (NTB driver core maintainer) has applied recent updates > to it. > > But in the interest of forward progress, I applied this patch with > Logan's ack to pci/misc for v4.20. Thanks. I'm not really sure what's going on in the NTB tree these days as Jon hasn't picked up anything in a while so it's probably better this went through PCI. It was originally created through the PCI tree, there shouldn't be any conflicts, and I can't see anyone else objecting. Logan
diff --git a/Documentation/switchtec.txt b/Documentation/switchtec.txt index f788264..d6f04dcc 100644 --- a/Documentation/switchtec.txt +++ b/Documentation/switchtec.txt @@ -23,7 +23,7 @@ The primary means of communicating with the Switchtec management firmware is through the Memory-mapped Remote Procedure Call (MRPC) interface. Commands are submitted to the interface with a 4-byte command identifier and up to 1KB of command specific data. The firmware will -respond with a 4 bytes return code and up to 1KB of command specific +respond with a 4-byte return code and up to 1KB of command specific data. The interface only processes a single command at a time. @@ -36,8 +36,8 @@ device: /dev/switchtec#, one for each management endpoint in the system. The char device has the following semantics: * A write must consist of at least 4 bytes and no more than 1028 bytes. - The first four bytes will be interpreted as the command to run and - the remainder will be used as the input data. A write will send the + The first 4 bytes will be interpreted as the Command ID and the + remainder will be used as the input data. A write will send the command to the firmware to begin processing. * Each write must be followed by exactly one read. Any double write will @@ -45,9 +45,9 @@ The char device has the following semantics: produce an error. * A read will block until the firmware completes the command and return - the four bytes of status plus up to 1024 bytes of output data. (The - length will be specified by the size parameter of the read call -- - reading less than 4 bytes will produce an error. + the 4-byte Command Return Value plus up to 1024 bytes of output + data. (The length will be specified by the size parameter of the read + call -- reading less than 4 bytes will produce an error.) * The poll call will also be supported for userspace applications that need to do other things while waiting for the command to complete. @@ -83,10 +83,20 @@ The following IOCTLs are also supported by the device: Non-Transparent Bridge (NTB) Driver =================================== -An NTB driver is provided for the switchtec hardware in switchtec_ntb. -Currently, it only supports switches configured with exactly 2 -partitions. It also requires the following configuration settings: +An NTB hardware driver is provided for the Switchtec hardware in +ntb_hw_switchtec. Currently, it only supports switches configured with +exactly 2 NT partitions and zero or more non-NT partitions. It also requires +the following configuration settings: -* Both partitions must be able to access each other's GAS spaces. +* Both NT partitions must be able to access each other's GAS spaces. Thus, the bits in the GAS Access Vector under Management Settings must be set to support this. +* Kernel configuration MUST include support for NTB (CONFIG_NTB needs + to be set) + +NT EP BAR 2 will be dynamically configured as a Direct Window, and +the configuration file does not need to configure it explicitly. + +Please refer to Documentation/ntb.txt in Linux source tree for an overall +understanding of the Linux NTB stack. ntb_hw_switchtec works as an NTB +Hardware Driver in this stack.