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| author | Shivaprasad G Bhat <sbhat@linux.ibm.com> | 2021-03-29 13:36:43 -0400 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-04-14 23:04:07 +1000 |
| commit | 75b7c05ebf902632f7f540c3eb0a8945c2d74aab (patch) | |
| tree | d3150b2c37b1363fc329a406c9988c25e5eef728 /Documentation/powerpc | |
| parent | af072b1a9d4d9edc24da84a071b0671e147026cb (diff) | |
| download | linux-next-75b7c05ebf902632f7f540c3eb0a8945c2d74aab.tar.gz | |
powerpc/papr_scm: Implement support for H_SCM_FLUSH hcall
Add support for ND_REGION_ASYNC capability if the device tree
indicates 'ibm,hcall-flush-required' property in the NVDIMM node.
Flush is done by issuing H_SCM_FLUSH hcall to the hypervisor.
If the flush request failed, the hypervisor is expected to
to reflect the problem in the subsequent nvdimm H_SCM_HEALTH call.
This patch prevents mmap of namespaces with MAP_SYNC flag if the
nvdimm requires an explicit flush[1].
References:
[1] https://github.com/avocado-framework-tests/avocado-misc-tests/blob/master/memory/ndctl.py.data/map_sync.c
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Use unsigned long / long instead of uint64_t/int64_t]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/161703936121.36.7260632399582101498.stgit@e1fbed493c87
Diffstat (limited to 'Documentation/powerpc')
| -rw-r--r-- | Documentation/powerpc/papr_hcalls.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/powerpc/papr_hcalls.rst b/Documentation/powerpc/papr_hcalls.rst index 48fcf1255a33..648f278eea8f 100644 --- a/Documentation/powerpc/papr_hcalls.rst +++ b/Documentation/powerpc/papr_hcalls.rst @@ -275,6 +275,20 @@ Health Bitmap Flags: Given a DRC Index collect the performance statistics for NVDIMM and copy them to the resultBuffer. +**H_SCM_FLUSH** + +| Input: *drcIndex, continue-token* +| Out: *continue-token* +| Return Value: *H_SUCCESS, H_Parameter, H_P2, H_BUSY* + +Given a DRC Index Flush the data to backend NVDIMM device. + +The hcall returns H_BUSY when the flush takes longer time and the hcall needs +to be issued multiple times in order to be completely serviced. The +*continue-token* from the output to be passed in the argument list of +subsequent hcalls to the hypervisor until the hcall is completely serviced +at which point H_SUCCESS or other error is returned by the hypervisor. + References ========== .. [1] "Power Architecture Platform Reference" |