You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
285 lines
12 KiB
XML
285 lines
12 KiB
XML
7 years ago
|
<appendix xmlns="http://docbook.org/ns/docbook"
|
||
|
|
xmlns:xl="http://www.w3.org/1999/xlink"
|
||
|
|
xml:id="dbdoclet.50569381_46906"
|
||
|
|
version="5.0"
|
||
|
|
xml:lang="en">
|
||
|
|
|
||
|
|
<title>EEH Error Processing</title>
|
||
|
|
|
||
|
|
<para>This appendix describes the architectural intent for EEH error processing.
|
||
|
|
This appendix does not attempt to illustrate all possible scenarios, and other
|
||
|
|
implementations are possible.</para>
|
||
|
|
|
||
|
|
<section xml:id="dbdoclet.50569381_11923">
|
||
|
|
<title>General Scenarios</title>
|
||
|
|
<para>In general, the device driver recovery consists of issuing an
|
||
|
|
<emphasis>ibm,read-slot-reset-state2</emphasis> call prior to doing any recovery
|
||
|
|
to determine if (1) the IOA is in the MMIO Stopped and DMA Stopped state (that is,
|
||
|
|
that an error has occurred which has put it into this state), and (2) whether or
|
||
|
|
not the PE has been reset by the platform in the process of entering the MMIO
|
||
|
|
Stopped and DMA Stopped state, and then doing one of the following:</para>
|
||
|
|
|
||
|
|
<orderedlist>
|
||
|
|
<listitem>
|
||
|
|
<para>Simplest approach: </para>
|
||
|
|
<itemizedlist>
|
||
|
|
<listitem>
|
||
|
|
<para>Reset the PE</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Reconfigure the PE</para>
|
||
|
|
</listitem>
|
||
|
|
</itemizedlist>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem xml:id="dbdoclet.50569381_39262">
|
||
|
|
<para>Most general approach (detailed more in <xref linkend="dbdoclet.50569381_38095"/>): </para>
|
||
|
|
<itemizedlist>
|
||
|
|
<listitem>
|
||
|
|
<para>Release the PE for <emphasis>Load</emphasis> /<emphasis>Store</emphasis></para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Issue <emphasis>Load</emphasis> /<emphasis> Store</emphasis> instructions t
|
||
|
|
o get any desired state information from the IOA</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Call the <emphasis>ibm,slot-error-detail</emphasis> RTAS call to get the
|
||
|
|
platform error information</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Log the error information</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Reset the PE</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Reconfigure the PE</para>
|
||
|
|
</listitem>
|
||
|
|
</itemizedlist>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Most robust (no reset unless necessary): </para>
|
||
|
|
<itemizedlist>
|
||
|
|
<listitem>
|
||
|
|
<para>Release the PE for <emphasis>Load</emphasis> /<emphasis>Store</emphasis></para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Issue <emphasis> Load</emphasis> /<emphasis> Store</emphasis> instructions
|
||
|
|
to get any desired state information from the IOA</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Call the <emphasis> ibm,slot-error-detail</emphasis> RTAS call to get the
|
||
|
|
platform error information</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Log the error information</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Device driver does IOA cleanup</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>Release the PE for DMA and restart operations (no reset) </para>
|
||
|
|
</listitem>
|
||
|
|
</itemizedlist>
|
||
|
|
</listitem>
|
||
|
|
</orderedlist>
|
||
|
|
|
||
|
|
<para>In any scenario, after several retries of a recoverable operation, the OS
|
||
|
|
may determine that further recovery efforts should cease. In such a case,
|
||
|
|
calling <emphasis>ibm,slot-error-detail</emphasis> with <emphasis>Function</emphasis> 2
|
||
|
|
(Permanent Error), in addition to returning error information, marks that the PE is
|
||
|
|
no longer accessible due to previous errors.</para>
|
||
|
|
</section>
|
||
|
|
|
||
|
|
<section xml:id="dbdoclet.50569381_38095">
|
||
|
|
<title>More Detail on the Most General Approach</title>
|
||
|
|
<para>The following gives a more detailed look at scenario #<xref linkend="dbdoclet.50569381_39262"/>
|
||
|
|
in <xref linkend="dbdoclet.50569381_11923"/>. This will be broken up into two groups of operations:
|
||
|
|
error logging and error recovery.</para>
|
||
|
|
<para>These scenarios assume that:</para>
|
||
|
|
|
||
|
|
<orderedlist>
|
||
|
|
<listitem>
|
||
|
|
<para>The <emphasis> ibm,configure-pe</emphasis> RTAS call is implemented.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The attempts at recovery stop when Max_Retries_Exceeded is true.</para>
|
||
|
|
</listitem>
|
||
|
|
</orderedlist>
|
||
|
|
|
||
|
|
<section>
|
||
|
|
<title>Error Logging</title>
|
||
|
|
|
||
|
|
<orderedlist>
|
||
|
|
<listitem>
|
||
|
|
<para>If the device driver is going to capture internal IOA-specific information
|
||
|
|
as a part of the error logging process or if the IOA controlled by the device driver
|
||
|
|
requires a longer wait after reset than the normal PCI specified minimum wait time,
|
||
|
|
then the device driver determines whether its IOA has been reset as a result of entering
|
||
|
|
EEH Stopped State, by looking at the <emphasis>PE Recovery Info</emphasis> output of
|
||
|
|
the <emphasis>ibm,read-slot-reset-state2</emphasis> RTAS call.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The OS or device driver insures that all MMIOs to the IOA(s) in the PE are finished.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>If the IOA requires longer wait after reset times than the specified minimum,
|
||
|
|
and the PE was reset (see step #1) as a result of the EEH event, then wait the
|
||
|
|
additional necessary time before continuing.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem xml:id="dbdoclet.50569381_59303">
|
||
|
|
<para>The OS or device driver
|
||
|
|
enables PE MMIOs by calling the <emphasis>ibm,set-eeh-option</emphasis> RTAS call
|
||
|
|
with <emphasis>Function</emphasis> 2. </para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The OS or device driver calls the <emphasis>ibm,configure-pe</emphasis> RTAS call. </para>
|
||
|
|
<orderedlist numeration="loweralpha">
|
||
|
|
<listitem>
|
||
|
|
<para>If the PCI fabric does not need configuring (the PE was not reset previous to the
|
||
|
|
call or was reset but was previously configured with <emphasis>ibm,configure-pe</emphasis> ),
|
||
|
|
then the call returns without doing anything, otherwise it attempts to configure
|
||
|
|
the fabric up to but not including the endpoint IOA configuration registers.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>If an EEH event occurs as a result of probing during the
|
||
|
|
<emphasis>ibm,configure-pe</emphasis> RTAS call that results in a
|
||
|
|
reset of the PE, the PE will be returned in the PE state of 2. Software
|
||
|
|
does not necessarily need to check this on return from the call. The case
|
||
|
|
where this occurs is expected to be rare, and probably signals a non-transient error.
|
||
|
|
In this case the software can continue on with the recovery phase of the EEH processing,
|
||
|
|
and will eventually hit the same EEH event on further processing.</para>
|
||
|
|
</listitem>
|
||
|
|
</orderedlist>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem xml:id="dbdoclet.50569381_74560">
|
||
|
|
<para>If the PE was
|
||
|
|
reset (see step #1) as a result of the EEH event, then if the device driver is
|
||
|
|
going to gather IOA-specific information for logging, it needs to finish the
|
||
|
|
configuration of the IOA PCI configuration registers, by restoring the PCI
|
||
|
|
configuration space registers of the IOA(s) in the PE (for example, BARs,
|
||
|
|
Memory Space Enable, etc.). </para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem xml:id="dbdoclet.50569381_29191">
|
||
|
|
<para>If desired, the
|
||
|
|
device driver gathers IOA-specific information via MMIOs, by doing MMIOs to its IOA.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The OS or device driver calls <emphasis>ibm,slot-error-detail</emphasis> .
|
||
|
|
Any data captured in step #<xref linkend="dbdoclet.50569381_29191"/> is passed in the
|
||
|
|
call. Note that maximum amount of data will be captured in some cases only when the
|
||
|
|
<emphasis>ibm,slot-error-detail</emphasis> call is made with PE not in the MMIO Stopped
|
||
|
|
State (as it should be in step #<xref linkend="dbdoclet.50569381_59303"/>). </para>
|
||
|
|
<orderedlist numeration="loweralpha">
|
||
|
|
<listitem>
|
||
|
|
<para>If Max_Retries_Exceeded is true, then call <emphasis>ibm,slot-error-detail</emphasis>
|
||
|
|
with <emphasis> Function</emphasis> 2 (Permanent Error).</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>If Max_Retries_Exceeded is not true, then call <emphasis>ibm,slot-error-detail</emphasis>
|
||
|
|
with <emphasis>Function</emphasis> 1(Temporary Error).</para>
|
||
|
|
</listitem>
|
||
|
|
</orderedlist>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The <emphasis>ibm,slot-error-detail</emphasis> RTAS call captures whatever
|
||
|
|
PCI config space registers it can between the configuration address passed in the call
|
||
|
|
and the system (PHB), and including at the configuration address and at the PHB, and
|
||
|
|
returns them along with the device specific data in an error log in the return information
|
||
|
|
from the call. This call may encounter another EEH event, in which case it returns what
|
||
|
|
information it can in the call, with a <emphasis>Status</emphasis> of 0 (Success).</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The OS or device driver logs the log entry returned from the
|
||
|
|
<emphasis>ibm,slot-error-detail</emphasis> RTAS call.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>If Max_Retries_Exceeded is not true, then the next step is PE Recovery,
|
||
|
|
otherwise stop and mark the IOA(s) in the PE as unusable.</para>
|
||
|
|
</listitem>
|
||
|
|
</orderedlist>
|
||
|
|
</section>
|
||
|
|
|
||
|
|
<section>
|
||
|
|
<title>PE Recovery</title>
|
||
|
|
|
||
|
|
<orderedlist>
|
||
|
|
<listitem>
|
||
|
|
<para>OS or device driver does a PE reset sequence. Note that this step is
|
||
|
|
required even if the PE was reset as a result of the initial EEH event, because
|
||
|
|
the error logging steps (for example, the <emphasis>ibm,configure-pe</emphasis>
|
||
|
|
or <emphasis> ibm,slot-error-detail</emphasis> calls) could have encountered
|
||
|
|
another EEH event. </para>
|
||
|
|
<orderedlist numeration="loweralpha">
|
||
|
|
<listitem>
|
||
|
|
<para>The device driver or OS calls <emphasis>ibm,set-slot-reset</emphasis> with
|
||
|
|
<emphasis>Function</emphasis> 1 or 3 to activate the reset.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The minimum reset active time is waited.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The device driver or OS calls <emphasis>ibm,set-slot-reset</emphasis> with
|
||
|
|
<emphasis>Function</emphasis> 0 to deactivate the reset.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The minimum reset inactive to first configuration cycles is waited.
|
||
|
|
If the IOA requires more than the standard PCI specified time, then wait that
|
||
|
|
longer time, instead.</para>
|
||
|
|
</listitem>
|
||
|
|
</orderedlist>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The OS or device driver calls <emphasis>ibm,configure-pe.</emphasis>
|
||
|
|
<note><para>If an EEH event occurs as a result of probing
|
||
|
|
during the <emphasis>ibm,configure-pe</emphasis> RTAS call that results in a reset
|
||
|
|
of the PE, the PE will be returned in the PE state of 2. Software does not necessarily
|
||
|
|
need to check this on return from the call. The case where this occurs is expected to
|
||
|
|
be rare, and probably signals a non-transient error. In this case the software can
|
||
|
|
continue on with the recovery phase of the EEH processing, and will eventually hit
|
||
|
|
the same EEH event on further processing.</para></note>
|
||
|
|
</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The device driver restores the PCI configuration spaces of the IOA(s) in the PE.</para>
|
||
|
|
</listitem>
|
||
|
|
|
||
|
|
<listitem>
|
||
|
|
<para>The device driver initializes the IOA for operations.</para>
|
||
|
|
</listitem>
|
||
|
|
</orderedlist>
|
||
|
|
|
||
|
|
</section>
|
||
|
|
</section>
|
||
|
|
</appendix>
|