From: Gaurav Batra <gbatra@xxxxxxxxxxxxxxxxxx> 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 § 14.5.4.2.3). The code has been in it's current form since it was initially merged. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Gaurav Batra <gbatra@xxxxxxxxxxxxxxxxxx> Reviewed-by: Brian King <brking@xxxxxxxxxxxxxxxxxx> [mpe: Tweak change log wording & add PAPR reference] Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://msgid.link/20230525143454.56878-1-gbatra@xxxxxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/platforms/pseries/iommu.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -311,13 +311,22 @@ static void tce_free_pSeriesLP(unsigned static void tce_freemulti_pSeriesLP(struct iommu_table *tbl, long tcenum, long npages) { u64 rc; + long rpages = npages; + unsigned long limit; if (!firmware_has_feature(FW_FEATURE_STUFF_TCE)) return tce_free_pSeriesLP(tbl->it_index, tcenum, tbl->it_page_shift, npages); - rc = plpar_tce_stuff((u64)tbl->it_index, - (u64)tcenum << tbl->it_page_shift, 0, npages); + do { + limit = min_t(unsigned long, rpages, 512); + + rc = plpar_tce_stuff((u64)tbl->it_index, + (u64)tcenum << tbl->it_page_shift, 0, limit); + + rpages -= limit; + tcenum += limit; + } while (rpages > 0 && !rc); if (rc && printk_ratelimit()) { printk("tce_freemulti_pSeriesLP: plpar_tce_stuff failed\n");
