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| author | Haren Myneni <haren@linux.ibm.com> | 2020-07-10 16:47:19 -0700 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-07-15 23:09:55 +1000 |
| commit | 6068e1a4427e88f5cc62f238d1baf94a8b824ef4 (patch) | |
| tree | f2e6f34ca9144a8a13c597806316ca012e419a7f /Documentation | |
| parent | b710d27bf72068b15b2f0305d825988183e2ff28 (diff) | |
| download | linux-6068e1a4427e88f5cc62f238d1baf94a8b824ef4.tar.bz2 | |
powerpc/vas: Report proper error code for address translation failure
P9 DD2 NX workbook (Table 4-36) says DMA controller uses CC=5
internally for translation fault handling. NX reserves CC=250 for
OS to notify user space when NX encounters address translation
failure on the request buffer. Not an issue in earlier releases
as NX does not get faults on kernel addresses.
This patch defines CSB_CC_FAULT_ADDRESS(250) and updates CSB.CC with
this proper error code for user space.
Fixes: c96c4436aba4 ("powerpc/vas: Update CSB and notify process for fault CRBs")
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
[mpe: Added Fixes tag and fix typo in comment]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/019fd53e7538c6f8f332d175df74b1815ef5aa8c.camel@linux.ibm.com
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/powerpc/vas-api.rst | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/powerpc/vas-api.rst b/Documentation/powerpc/vas-api.rst index 1217c2f1595e..788dc8375a0e 100644 --- a/Documentation/powerpc/vas-api.rst +++ b/Documentation/powerpc/vas-api.rst @@ -213,7 +213,7 @@ request buffers are not in memory. The operating system handles the fault by updating CSB with the following data: csb.flags = CSB_V; - csb.cc = CSB_CC_TRANSLATION; + csb.cc = CSB_CC_FAULT_ADDRESS; csb.ce = CSB_CE_TERMINATION; csb.address = fault_address; |