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authorHaren Myneni <haren@linux.ibm.com>2020-07-10 16:47:19 -0700
committerMichael Ellerman <mpe@ellerman.id.au>2020-07-15 23:09:55 +1000
commit6068e1a4427e88f5cc62f238d1baf94a8b824ef4 (patch)
treef2e6f34ca9144a8a13c597806316ca012e419a7f /Documentation/powerpc
parentb710d27bf72068b15b2f0305d825988183e2ff28 (diff)
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/powerpc')
-rw-r--r--Documentation/powerpc/vas-api.rst2
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;