um: Use asm-generic/dma-mapping.h

jmberg-intel · richardweinberger · commit 365719035526 · 2022-05-27T09:00:45.000+02:00
If DMA (PCI over virtio) is enabled, then some drivers may enable CONFIG_DMA_OPS as well, and then we pull in the x86 definition of get_arch_dma_ops(), which uses the dma_ops symbol, which isn't defined. Since we don't have real DMA ops nor any kind of IOMMU fix this in the simplest possible way: pull in the asm-generic file instead of inheriting the x86 one. It's not clear why those drivers that do (e.g. VDPA) "select DMA_OPS", and if they'd even work with this, but chances are nobody will be wanting to do that anyway, so fixing the build failure is good enough. Reported-by: Randy Dunlap <rdunlap@infradead.org> Fixes: 68f5d3f ("um: add PCI over virtio emulation driver") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Tested-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild
@@ -4,6 +4,7 @@ generic-y += bug.h
 generic-y += compat.h
 generic-y += current.h
 generic-y += device.h
+generic-y += dma-mapping.h
 generic-y += emergency-restart.h
 generic-y += exec.h
 generic-y += extable.h
