Currently pnv_ioda_setup_bus_dma() is outside of a CONFIG_IOMMU_API guard
and if CONFIG_IOMMU_API=n the build can fail if the compiler sets
-Werror=unused-function, because pnv_ioda_setup_bus_dma() is only used in
functions guarded by a CONFIG_IOMMU_API guard.
That issue can be easily reproduced using the skiroot_defconfig. For other
configs, like powernv_defconfig, that issue is hidden by the fact that
if CONFIG_IOMMU_SUPPORT is enabled plus other common IOMMU options, like
CONFIG_OF_IOMMU, by default CONFIG_IOMMU_API is enabled as well. Hence, for
powernv_defconfig, it's necessary to set CONFIG_IOMMU_SUPPORT=n to make the
build fail, because CONFIG_PCI=y and pci-ioda.c is included in the build,
but since CONFIG_IOMMU_SUPPORT=n the CONFIG_IOMMU_API is disabled, breaking
the build.
This commit fixes that build issue by moving the pnv_ioda_setup_bus_dma()
inside a CONFIG_IOMMU_API guard, so when CONFIG_IOMMU_API is disabled that
function is not defined.
Signed-off-by: Gustavo Romero <redacted>
---
arch/powerpc/platforms/powernv/pci-ioda.c | 26 +++++++++++------------
1 file changed, 13 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 73a63efcf855..743d840712da 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1885,19 +1885,6 @@ static bool pnv_pci_ioda_iommu_bypass_supported(struct pci_dev *pdev,
return false;
}
-static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe, struct pci_bus *bus)
-{
- struct pci_dev *dev;
-
- list_for_each_entry(dev, &bus->devices, bus_list) {
- set_iommu_table_base(&dev->dev, pe->table_group.tables[0]);
- dev->dev.archdata.dma_offset = pe->tce_bypass_base;
-
- if ((pe->flags & PNV_IODA_PE_BUS_ALL) && dev->subordinate)
- pnv_ioda_setup_bus_dma(pe, dev->subordinate);
- }
-}
-
static inline __be64 __iomem *pnv_ioda_get_inval_reg(struct pnv_phb *phb,
bool real_mode)
{@@ -2501,6 +2488,19 @@ static long pnv_pci_ioda2_unset_window(struct iommu_table_group *table_group,
#endif
#ifdef CONFIG_IOMMU_API
+static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe, struct pci_bus *bus)
+{
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ set_iommu_table_base(&dev->dev, pe->table_group.tables[0]);
+ dev->dev.archdata.dma_offset = pe->tce_bypass_base;
+
+ if ((pe->flags & PNV_IODA_PE_BUS_ALL) && dev->subordinate)
+ pnv_ioda_setup_bus_dma(pe, dev->subordinate);
+ }
+}
+
unsigned long pnv_pci_ioda2_get_table_size(__u32 page_shift,
__u64 window_size, __u32 levels)
{--
2.17.1
On Wed, Jul 29, 2020 at 8:35 AM Gustavo Romero [off-list ref] wrote:
Currently pnv_ioda_setup_bus_dma() is outside of a CONFIG_IOMMU_API guard
and if CONFIG_IOMMU_API=n the build can fail if the compiler sets
-Werror=unused-function, because pnv_ioda_setup_bus_dma() is only used in
functions guarded by a CONFIG_IOMMU_API guard.
That issue can be easily reproduced using the skiroot_defconfig. For other
configs, like powernv_defconfig, that issue is hidden by the fact that
if CONFIG_IOMMU_SUPPORT is enabled plus other common IOMMU options, like
CONFIG_OF_IOMMU, by default CONFIG_IOMMU_API is enabled as well. Hence, for
powernv_defconfig, it's necessary to set CONFIG_IOMMU_SUPPORT=n to make the
build fail, because CONFIG_PCI=y and pci-ioda.c is included in the build,
but since CONFIG_IOMMU_SUPPORT=n the CONFIG_IOMMU_API is disabled, breaking
the build.
This commit fixes that build issue by moving the pnv_ioda_setup_bus_dma()
inside a CONFIG_IOMMU_API guard, so when CONFIG_IOMMU_API is disabled that
function is not defined.
I think a fix for this is already in -next.
Hi Oliver,
On 7/28/20 7:50 PM, Oliver O'Halloran wrote:
On Wed, Jul 29, 2020 at 8:35 AM Gustavo Romero [off-list ref] wrote:
quoted
Currently pnv_ioda_setup_bus_dma() is outside of a CONFIG_IOMMU_API guard
and if CONFIG_IOMMU_API=n the build can fail if the compiler sets
-Werror=unused-function, because pnv_ioda_setup_bus_dma() is only used in
functions guarded by a CONFIG_IOMMU_API guard.
That issue can be easily reproduced using the skiroot_defconfig. For other
configs, like powernv_defconfig, that issue is hidden by the fact that
if CONFIG_IOMMU_SUPPORT is enabled plus other common IOMMU options, like
CONFIG_OF_IOMMU, by default CONFIG_IOMMU_API is enabled as well. Hence, for
powernv_defconfig, it's necessary to set CONFIG_IOMMU_SUPPORT=n to make the
build fail, because CONFIG_PCI=y and pci-ioda.c is included in the build,
but since CONFIG_IOMMU_SUPPORT=n the CONFIG_IOMMU_API is disabled, breaking
the build.
This commit fixes that build issue by moving the pnv_ioda_setup_bus_dma()
inside a CONFIG_IOMMU_API guard, so when CONFIG_IOMMU_API is disabled that
function is not defined.
I think a fix for this is already in -next.
Indeed.
For the records, it's fixed in -next by:
commit e3417faec526cbf97773dca691dcd743f5bfeb64
Author: Oliver O'Halloran [off-list ref]
Date: Sun Jul 5 23:35:57 2020 +1000
powerpc/powernv: Move pnv_ioda_setup_bus_dma under CONFIG_IOMMU_API
pnv_ioda_setup_bus_dma() is only used when a passed through PE is
returned to the host. If the kernel is built without IOMMU support
this is dead code. Move it under the #ifdef with the rest of the
IOMMU API support.
Reported-by: kernel test robot [off-list ref]
Signed-off-by: Oliver O'Halloran [off-list ref]
Reviewed-by: Alexey Kardashevskiy [off-list ref]
Signed-off-by: Michael Ellerman [off-list ref]
Link: https://lore.kernel.org/r/20200705133557.443607-2-oohall@gmail.com
Thanks.
Cheers,
Gustavo