> On Fri, Jun 10, 2022 at 02:25:18AM -0700, Wang Wenhu wrote: > > It is recommended in the "Conditional Compilation" chapter of kernel > > coding-style documentation that preprocessor conditionals should not > > be used in .c files wherever possible. > > > > As for the micro CONFIG_HAVE_IOREMAP_PROT, now it's a proper chance > > to eliminate it in .c files as we add a no-op function defination > > in the header file if the micro is not enabled. > > > > The main trigger for this patch is an UIO driver series and as Greg > > commented we'd better not use such preprocessor contionals. > > See: https://lore.kernel.org/lkml/YqHy1uXwCLlJmftr@xxxxxxxxx/ > > For there is little work to do with the UIO driver, I try to push > > this commit independently. > > > > Signed-off-by: Wang Wenhu <lonehugo@xxxxxxxxxxx> > > --- > > drivers/char/mem.c | 2 -- > > drivers/fpga/dfl-afu-main.c | 2 -- > > drivers/pci/mmap.c | 2 -- > > drivers/uio/uio.c | 2 -- > > include/linux/mm.h | 8 ++++++++ > > mm/memory.c | 4 ---- > > 6 files changed, 8 insertions(+), 12 deletions(-) > > > > diff --git a/drivers/char/mem.c b/drivers/char/mem.c > > index 84ca98ed1dad..40186a441e38 100644 > > --- a/drivers/char/mem.c > > +++ b/drivers/char/mem.c > > @@ -354,9 +354,7 @@ static inline int private_mapping_ok(struct vm_area_struct *vma) > > #endif > > > > static const struct vm_operations_struct mmap_mem_ops = { > > -#ifdef CONFIG_HAVE_IOREMAP_PROT > > .access = generic_access_phys > > -#endif > > }; > > > > static int mmap_mem(struct file *file, struct vm_area_struct *vma) > > diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c > > index 7f621e96d3b8..833e14806c7a 100644 > > --- a/drivers/fpga/dfl-afu-main.c > > +++ b/drivers/fpga/dfl-afu-main.c > > @@ -797,9 +797,7 @@ static long afu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > > } > > > > static const struct vm_operations_struct afu_vma_ops = { > > -#ifdef CONFIG_HAVE_IOREMAP_PROT > > .access = generic_access_phys, > > -#endif > > }; > > > > static int afu_mmap(struct file *filp, struct vm_area_struct *vma) > > diff --git a/drivers/pci/mmap.c b/drivers/pci/mmap.c > > index b8c9011987f4..1dcfabf80453 100644 > > --- a/drivers/pci/mmap.c > > +++ b/drivers/pci/mmap.c > > @@ -35,9 +35,7 @@ int pci_mmap_page_range(struct pci_dev *pdev, int bar, > > #endif > > > > static const struct vm_operations_struct pci_phys_vm_ops = { > > -#ifdef CONFIG_HAVE_IOREMAP_PROT > > .access = generic_access_phys, > > -#endif > > }; > > > > int pci_mmap_resource_range(struct pci_dev *pdev, int bar, > > diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c > > index 43afbb7c5ab9..c9205a121007 100644 > > --- a/drivers/uio/uio.c > > +++ b/drivers/uio/uio.c > > @@ -719,9 +719,7 @@ static int uio_mmap_logical(struct vm_area_struct *vma) > > } > > > > static const struct vm_operations_struct uio_physical_vm_ops = { > > -#ifdef CONFIG_HAVE_IOREMAP_PROT > > .access = generic_access_phys, > > -#endif > > }; > > > > static int uio_mmap_physical(struct vm_area_struct *vma) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > > index bc8f326be0ce..66d0cff6054e 100644 > > --- a/include/linux/mm.h > > +++ b/include/linux/mm.h > > @@ -1857,8 +1857,16 @@ int follow_pfn(struct vm_area_struct *vma, unsigned long address, > > unsigned long *pfn); > > int follow_phys(struct vm_area_struct *vma, unsigned long address, > > unsigned int flags, unsigned long *prot, resource_size_t *phys); > > +#ifdef CONFIG_HAVE_IOREMAP_PROT > > int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, > > void *buf, int len, int write); > > +#else > > +int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, > > + void *buf, int len, int write) > > This needs to be an inline function, right? > > Did you test build this? > > thanks, > > greg k-h Surely it should have been static inline orelse undefine error happens. I tested with the micro enabled on ppc, and disabled on arm64, but I missed up configurations on arm testing code that it's still on. I will re-confirm it and update the patch later. thanks, Wenhu