On Fri, Aug 28, 2020 at 05:01:39PM -0700, Randy Dunlap wrote: > Export min_low_pfn & max_low_pfn in mm/memblock.c to fix build errors > on arch/microblaze/ and arch/ia64/: (e.g.) Please don't. This would give driver developers a wrong impression that these variables can be used to query memory boundaries, but this is not the case, at least not on all architectures. I would prefer fixing it up locally for microblaze and ia64. > ERROR: "max_low_pfn" [drivers/rpmsg/virtio_rpmsg_bus.ko] undefined! > ERROR: "min_low_pfn" [drivers/rpmsg/virtio_rpmsg_bus.ko] undefined! > ERROR: "max_low_pfn" [drivers/mtd/spi-nor/spi-nor.ko] undefined! > ERROR: "min_low_pfn" [drivers/mtd/spi-nor/spi-nor.ko] undefined! > ERROR: "min_low_pfn" [drivers/mtd/nand/raw/nand.ko] undefined! > ERROR: "max_low_pfn" [drivers/mtd/nand/raw/nand.ko] undefined! > ERROR: "max_low_pfn" [drivers/rapidio/devices/rio_mport_cdev.ko] undefined! > ERROR: "min_low_pfn" [drivers/rapidio/devices/rio_mport_cdev.ko] undefined! > ERROR: "min_low_pfn" [drivers/hwtracing/intel_th/intel_th_msu.ko] undefined! > ERROR: "max_low_pfn" [drivers/hwtracing/intel_th/intel_th_msu.ko] undefined! > ERROR: "min_low_pfn" [drivers/crypto/cavium/nitrox/n5pf.ko] undefined! > ERROR: "max_low_pfn" [drivers/crypto/cavium/nitrox/n5pf.ko] undefined! > ERROR: "max_low_pfn" [drivers/md/dm-integrity.ko] undefined! > ERROR: "min_low_pfn" [drivers/md/dm-integrity.ko] undefined! > ERROR: "max_low_pfn" [crypto/tcrypt.ko] undefined! > ERROR: "min_low_pfn" [crypto/tcrypt.ko] undefined! > > In both arches, these variables are referenced in > arch/$ARCH/include/asm/page.h. > > Mike had/has an alternate patch for Microblaze: > https://lore.kernel.org/lkml/20200630111519.GA1951986@xxxxxxxxxxxxx/ > > David suggested just exporting min_low_pfn & max_low_pfn in > mm/memblock.c: > https://lore.kernel.org/lkml/alpine.DEB.2.22.394.2006291911220.1118534@xxxxxxxxxxxxxxxxxxxxxxxxx/ > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > Suggested-by: David Rientjes <rientjes@xxxxxxxxxx> > Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> > Cc: linux-mm@xxxxxxxxx > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: David Rientjes <rientjes@xxxxxxxxxx> > Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx> > Cc: Michal Simek <monstr@xxxxxxxxx> > Cc: Michal Simek <michal.simek@xxxxxxxxxx> > Cc: Tony Luck <tony.luck@xxxxxxxxx> > Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> > Cc: linux-ia64@xxxxxxxxxxxxxxx > --- > mm/memblock.c | 2 ++ > 1 file changed, 2 insertions(+) > > --- linux-next-20200825.orig/mm/memblock.c > +++ linux-next-20200825/mm/memblock.c > @@ -99,6 +99,8 @@ EXPORT_SYMBOL(contig_page_data); > > unsigned long max_low_pfn; > unsigned long min_low_pfn; > +EXPORT_SYMBOL(min_low_pfn); > +EXPORT_SYMBOL(max_low_pfn); > unsigned long max_pfn; > unsigned long long max_possible_pfn; > -- Sincerely yours, Mike.
