# \[PATCH 6.6.y 0/1\] Fix ppc64 build error introduced in v6.6.161 - Subsystems: LINUX FOR POWERPC (32-BIT AND 64-BIT), THE REST - Maintainers: Madhavan Srinivasan, Linus Torvalds - Series: 1 patch touching 1 file, +6/-0 - List: linuxppc-dev - 4 messages, 3 authors - Page: https://ratatoskr.run/linuxppc-dev/2026/11/17874607/t ## \[PATCH 6.6.y 0/1\] Fix ppc64 build error introduced in v6.6.161 - From: Stephen Brennan \ - Date: 2026-11-05 23:24:30 - Message: https://ratatoskr.run/linuxppc-dev/2026/11/17874607.md ```text Hello, Drgn builds stable kernels regularly in order to run its test suite against. We encountered an error compiling v6.6.161 for ppc64. The 6.6.161 update contained "powerpc/iommu: Move pSeries specific functions to pseries/iommu.c" [1]. On ppc64 configurations without CONFIG_IOMMU_API, this breaks the build (details in the patch). Thank you! Stephen https://lore.kernel.org/all/20261017160448.281572781@linuxfoundation.org/ Stephen Brennan (1): powerpc/pseries/iommu: Restore CONFIG_IOMMU_API dependency arch/powerpc/platforms/pseries/iommu.c | 6 ++++++ 1 file changed, 6 insertions(+) -- 2.52.0 ``` ## \[PATCH 6.6.y 1/1\] powerpc/pseries/iommu: Restore CONFIG\_IOMMU\_API dependency - From: Stephen Brennan \ - Date: 2026-11-05 23:24:30 - Message: https://ratatoskr.run/linuxppc-dev/2026/11/17874608.md ```text In stable v6.6.161 there is a build error with ppc64 when CONFIG_IOMMU_API is not enabled: arch/powerpc/platforms/pseries/iommu.c: In function 'iommu_take_ownership': arch/powerpc/platforms/pseries/iommu.c:69:25: error: 'struct iommu_table_ops' has no member named 'xchg_no_kill' 69 | if (!tbl->it_ops->xchg_no_kill) | ^~ AS arch/powerpc/lib/copy_mc_64.o arch/powerpc/platforms/pseries/iommu.c: At top level: arch/powerpc/platforms/pseries/iommu.c:1787:37: error: 'spapr_tce_table_group_ops' defined but not used [-Werror=unused-variable] 1787 | static struct iommu_table_group_ops spapr_tce_table_group_ops = { | ^~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors This is due to stable v6.6.161 commit 1e9dfe15404d ("powerpc/iommu: Move pSeries specific functions to pseries/iommu.c"). It was included as a stable-dep-of commit 8f70caad82e9 ("powerpc/pseries/iommu: IOMMU incorrectly marks MMIO range in DDW"). It was backported without its associated fix: commit af199e6ca29c ("powerpc/pseries/iommu: Define spapr_tce_table_group_ops only with CONFIG_IOMMU_API"). The code was supposed to only build under CONFIG_IOMMU_API, but the new location doesn't have this condition. Unfortunately, the fixing commit comes after a fairly large refactor, and doesn't apply on v6.16.161. Instead, apply the ifdefs where they would belong prior to the refactor. Signed-off-by: Stephen Brennan --- arch/powerpc/platforms/pseries/iommu.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index 6a45e3e86f79b..a79927e870a87 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -54,6 +54,7 @@ enum { DDW_EXT_QUERY_OUT_SIZE = 2 }; +#ifdef CONFIG_IOMMU_API static int iommu_take_ownership(struct iommu_table *tbl) { unsigned long flags, i, sz = (tbl->it_size + 7) >> 3; @@ -104,6 +105,7 @@ static void iommu_release_ownership(struct iommu_table *tbl) spin_unlock(&tbl->pools[i].lock); spin_unlock_irqrestore(&tbl->large_pool.lock, flags); } +#endif static struct iommu_table *iommu_pseries_alloc_table(int node) { @@ -118,7 +120,9 @@ static struct iommu_table *iommu_pseries_alloc_table(int node) return tbl; } +#ifdef CONFIG_IOMMU_API static struct iommu_table_group_ops spapr_tce_table_group_ops; +#endif static struct iommu_table_group *iommu_pseries_alloc_group(int node) { @@ -1702,6 +1706,7 @@ static bool iommu_bypass_supported_pSeriesLP(struct pci_dev *pdev, u64 dma_mask) return false; } +#ifdef CONFIG_IOMMU_API /* * A simple iommu_table_group_ops which only allows reusing the existing * iommu_table. This handles VFIO for POWER7 or the nested KVM. @@ -1792,6 +1797,7 @@ static struct iommu_table_group_ops spapr_tce_table_group_ops = { .take_ownership = spapr_tce_take_ownership, .release_ownership = spapr_tce_release_ownership, }; +#endif static int iommu_mem_notifier(struct notifier_block *nb, unsigned long action, void *data) -- 2.52.0 ``` ## Re: \[PATCH 6.6.y 1/1\] powerpc/pseries/iommu: Restore CONFIG\_IOMMU\_API dependency - From: Sasha Levin \ - Date: 2026-11-06 16:36:08 - Message: https://ratatoskr.run/linuxppc-dev/2026/11/17880050.md ```text > powerpc/pseries/iommu: Restore CONFIG_IOMMU_API dependency This is a hand-adapted replacement for af199e6ca29c ("powerpc/pseries/iommu: Define spapr_tce_table_group_ops only with CONFIG_IOMMU_API") rather than a clean cherry-pick, and it has no ack from the powerpc side. Michael, Madhavan: could one of you review it? I will queue it for 6.6 once you are happy with it. -- Thanks, Sasha ``` ## Re: \[PATCH 6.6.y 1/1\] powerpc/pseries/iommu: Restore CONFIG\_IOMMU\_API dependency - From: Madhavan Srinivasan \ - Date: 2026-11-10 05:01:53 - Message: https://ratatoskr.run/linuxppc-dev/2026/11/17903051.md ```text On 11/6/26 4:54 AM, Stephen Brennan wrote: > In stable v6.6.161 there is a build error with ppc64 when > CONFIG_IOMMU_API is not enabled: > > arch/powerpc/platforms/pseries/iommu.c: In function 'iommu_take_ownership': > arch/powerpc/platforms/pseries/iommu.c:69:25: error: 'struct iommu_table_ops' has no member named 'xchg_no_kill' > 69 | if (!tbl->it_ops->xchg_no_kill) > | ^~ > AS arch/powerpc/lib/copy_mc_64.o > arch/powerpc/platforms/pseries/iommu.c: At top level: > arch/powerpc/platforms/pseries/iommu.c:1787:37: error: 'spapr_tce_table_group_ops' defined but not used [-Werror=unused-variable] > 1787 | static struct iommu_table_group_ops spapr_tce_table_group_ops = { > | ^~~~~~~~~~~~~~~~~~~~~~~~~ > cc1: all warnings being treated as errors > > This is due to stable v6.6.161 commit 1e9dfe15404d ("powerpc/iommu: Move > pSeries specific functions to pseries/iommu.c"). It was included as a > stable-dep-of commit 8f70caad82e9 ("powerpc/pseries/iommu: IOMMU > incorrectly marks MMIO range in DDW"). > > It was backported without its associated fix: commit af199e6ca29c > ("powerpc/pseries/iommu: Define spapr_tce_table_group_ops only with > CONFIG_IOMMU_API"). > > The code was supposed to only build under CONFIG_IOMMU_API, but the new > location doesn't have this condition. Unfortunately, the fixing commit > comes after a fairly large refactor, and doesn't apply on v6.16.161. > Instead, apply the ifdefs where they would belong prior to the refactor. Looks fine to me Acked-by: Madhavan Srinivasan > Signed-off-by: Stephen Brennan > --- > arch/powerpc/platforms/pseries/iommu.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c > index 6a45e3e86f79b..a79927e870a87 100644 > --- a/arch/powerpc/platforms/pseries/iommu.c > +++ b/arch/powerpc/platforms/pseries/iommu.c > @@ -54,6 +54,7 @@ enum { > DDW_EXT_QUERY_OUT_SIZE = 2 > }; > > +#ifdef CONFIG_IOMMU_API > static int iommu_take_ownership(struct iommu_table *tbl) > { > unsigned long flags, i, sz = (tbl->it_size + 7) >> 3; > @@ -104,6 +105,7 @@ static void iommu_release_ownership(struct iommu_table *tbl) > spin_unlock(&tbl->pools[i].lock); > spin_unlock_irqrestore(&tbl->large_pool.lock, flags); > } > +#endif > > static struct iommu_table *iommu_pseries_alloc_table(int node) > { > @@ -118,7 +120,9 @@ static struct iommu_table *iommu_pseries_alloc_table(int node) > return tbl; > } > > +#ifdef CONFIG_IOMMU_API > static struct iommu_table_group_ops spapr_tce_table_group_ops; > +#endif > > static struct iommu_table_group *iommu_pseries_alloc_group(int node) > { > @@ -1702,6 +1706,7 @@ static bool iommu_bypass_supported_pSeriesLP(struct pci_dev *pdev, u64 dma_mask) > return false; > } > > +#ifdef CONFIG_IOMMU_API > /* > * A simple iommu_table_group_ops which only allows reusing the existing > * iommu_table. This handles VFIO for POWER7 or the nested KVM. > @@ -1792,6 +1797,7 @@ static struct iommu_table_group_ops spapr_tce_table_group_ops = { > .take_ownership = spapr_tce_take_ownership, > .release_ownership = spapr_tce_release_ownership, > }; > +#endif > > static int iommu_mem_notifier(struct notifier_block *nb, unsigned long action, > void *data) ```