powerpc/iommu: Limit number of TCEs to 512 for H_STUFF_TCE hcall
commit
9d2ccf00bddc268045e3d65a8108d61ada0e4b4e upstream.
Currently in tce_freemulti_pSeriesLP() there is no limit on how many
TCEs are passed to the H_STUFF_TCE hcall. This has not caused an issue
until now, but newer firmware releases have started enforcing a limit of
512 TCEs per call.
The limit is correct per the specification (PAPR v2.12 ยง 14.5.4.2.3).
The code has been in it's current form since it was initially merged.
Cc: stable@vger.kernel.org
Signed-off-by: Gaurav Batra <gbatra@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
[mpe: Tweak change log wording & add PAPR reference]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230525143454.56878-1-gbatra@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>