Changes since v2 [1]: [1]: https://lwn.net/Articles/643437/ 1/ Linus pointed out that comparing a __pfn_t value against PAGE_OFFSET was both inefficient, when PAGE_OFFSET is a large constant, and incorrect for archs that set PAGE_OFFSET to zero. Instead, take advantage of the standard alignment of a 'struct page *' to store a set of flags. In this patch set the only flag defined is PFN_DEV to indicate "this pfn originated from device memory". A potential future flag is PFN_DEV_MAPPED if the device has arranged for an associated struct page for the __pfn_t. 2/ Fix DAX against pmem device disable/removal using kmap_atomic_pfn_t(). We can later exploit these annotations to protect against the "stray pointer problem" whereby a kernel bug in an unrelated part of the system causes inadvertent scribbling over pmem. 3/ Made the series easier to merge as it no longer causes compile errors by default for new usages of bv_page arriving in the next merge window. 4/ arch/x86/kernel/kmap.c => mm/pfn.c since it is generic functionality. 5/ Updated the kmap_atomic() helpers in bio.h to use kmap_atomic_pfn_t() Incremental diffstat: arch/powerpc/sysdev/axonram.c | 9 +++++-- arch/x86/Kconfig | 2 +- arch/x86/kernel/Makefile | 1 - block/bio.c | 4 +-- block/blk-core.c | 2 +- drivers/block/brd.c | 3 +-- drivers/block/pmem.c | 9 ++++--- drivers/s390/block/dcssblk.c | 11 +++++--- fs/block_dev.c | 4 +-- fs/dax.c | 57 ++++++++++++++++++++++++++++++++-------- include/asm-generic/pfn.h | 73 ++++++++++++++++++++++++++++++++++------------------ include/linux/bio.h | 14 +++++----- include/linux/blk_types.h | 2 +- include/linux/blkdev.h | 7 +++-- init/Kconfig | 12 ++++----- mm/Makefile | 1 + arch/x86/kernel/kmap.c => mm/pfn.c | 0 17 files changed, 140 insertions(+), 71 deletions(-) rename arch/x86/kernel/kmap.c => mm/pfn.c (100%) While we wait for the debate [2] to settle about what to do about i/o paths that ostensibly require struct page, these patches enable a stacked/tiered storage driver to manage pmem fronting slower storage media. [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-May/000727.html --- Dan Williams (10): arch: introduce __pfn_t for persistenti/device memory block: add helpers for accessing a bio_vec page block: convert .bv_page to .bv_pfn bio_vec dma-mapping: allow archs to optionally specify a ->map_pfn() operation scatterlist: use sg_phys() x86: support dma_map_pfn() x86: support kmap_atomic_pfn_t() for persistent memory block: convert kmap helpers to kmap_atomic_pfn_t() dax: convert to __pfn_t block: base support for pfn i/o Matthew Wilcox (1): scatterlist: support "page-less" (__pfn_t only) entries Documentation/block/biodoc.txt | 4 + arch/Kconfig | 6 ++ arch/arm/mm/dma-mapping.c | 2 - arch/microblaze/kernel/dma.c | 2 - arch/powerpc/sysdev/axonram.c | 13 ++- arch/x86/Kconfig | 7 ++ arch/x86/kernel/amd_gart_64.c | 22 +++++- arch/x86/kernel/pci-nommu.c | 22 +++++- arch/x86/kernel/pci-swiotlb.c | 4 + arch/x86/pci/sta2x11-fixup.c | 4 + arch/x86/xen/pci-swiotlb-xen.c | 4 + block/bio-integrity.c | 8 +- block/bio.c | 82 +++++++++++++++------- block/blk-core.c | 13 +++ block/blk-integrity.c | 7 +- block/blk-lib.c | 2 - block/blk-merge.c | 15 ++-- block/bounce.c | 26 +++---- drivers/block/aoe/aoecmd.c | 8 +- drivers/block/brd.c | 7 +- drivers/block/drbd/drbd_bitmap.c | 5 + drivers/block/drbd/drbd_main.c | 6 +- drivers/block/drbd/drbd_receiver.c | 4 + drivers/block/drbd/drbd_worker.c | 3 + drivers/block/floppy.c | 6 +- drivers/block/loop.c | 13 ++- drivers/block/nbd.c | 8 +- drivers/block/nvme-core.c | 2 - drivers/block/pktcdvd.c | 11 ++- drivers/block/pmem.c | 19 ++++- drivers/block/ps3disk.c | 2 - drivers/block/ps3vram.c | 2 - drivers/block/rbd.c | 2 - drivers/block/rsxx/dma.c | 2 - drivers/block/umem.c | 2 - drivers/block/zram/zram_drv.c | 10 +-- drivers/dma/ste_dma40.c | 5 - drivers/iommu/amd_iommu.c | 21 ++++-- drivers/iommu/intel-iommu.c | 26 +++++-- drivers/iommu/iommu.c | 2 - drivers/md/bcache/btree.c | 4 + drivers/md/bcache/debug.c | 6 +- drivers/md/bcache/movinggc.c | 2 - drivers/md/bcache/request.c | 6 +- drivers/md/bcache/super.c | 10 +-- drivers/md/bcache/util.c | 5 + drivers/md/bcache/writeback.c | 2 - drivers/md/dm-crypt.c | 12 ++- drivers/md/dm-io.c | 2 - drivers/md/dm-log-writes.c | 14 ++-- drivers/md/dm-verity.c | 2 - drivers/md/raid1.c | 50 +++++++------ drivers/md/raid10.c | 38 +++++----- drivers/md/raid5.c | 6 +- drivers/mmc/card/queue.c | 4 + drivers/s390/block/dasd_diag.c | 2 - drivers/s390/block/dasd_eckd.c | 14 ++-- drivers/s390/block/dasd_fba.c | 6 +- drivers/s390/block/dcssblk.c | 15 +++- drivers/s390/block/scm_blk.c | 2 - drivers/s390/block/scm_blk_cluster.c | 2 - drivers/s390/block/xpram.c | 2 - drivers/scsi/mpt2sas/mpt2sas_transport.c | 6 +- drivers/scsi/mpt3sas/mpt3sas_transport.c | 6 +- drivers/scsi/sd_dif.c | 4 + drivers/staging/android/ion/ion_chunk_heap.c | 4 + drivers/staging/lustre/lustre/llite/lloop.c | 2 - drivers/target/target_core_file.c | 4 + drivers/xen/biomerge.c | 4 + drivers/xen/swiotlb-xen.c | 29 +++++--- fs/9p/vfs_addr.c | 2 - fs/block_dev.c | 4 + fs/btrfs/check-integrity.c | 6 +- fs/btrfs/compression.c | 12 ++- fs/btrfs/disk-io.c | 5 + fs/btrfs/extent_io.c | 8 +- fs/btrfs/file-item.c | 8 +- fs/btrfs/inode.c | 19 +++-- fs/btrfs/raid56.c | 4 + fs/btrfs/volumes.c | 2 - fs/buffer.c | 4 + fs/dax.c | 62 +++++++++++++--- fs/direct-io.c | 2 - fs/exofs/ore.c | 4 + fs/exofs/ore_raid.c | 2 - fs/ext4/page-io.c | 2 - fs/ext4/readpage.c | 4 + fs/f2fs/data.c | 4 + fs/f2fs/segment.c | 2 - fs/gfs2/lops.c | 4 + fs/jfs/jfs_logmgr.c | 4 + fs/logfs/dev_bdev.c | 10 +-- fs/mpage.c | 2 - fs/splice.c | 2 - include/asm-generic/dma-mapping-common.h | 30 ++++++++ include/asm-generic/memory_model.h | 1 include/asm-generic/pfn.h | 95 +++++++++++++++++++++++++ include/asm-generic/scatterlist.h | 10 +++ include/crypto/scatterwalk.h | 10 +++ include/linux/bio.h | 28 ++++--- include/linux/blk_types.h | 31 ++++++++ include/linux/blkdev.h | 9 +- include/linux/dma-debug.h | 23 +++++- include/linux/dma-mapping.h | 8 ++ include/linux/highmem.h | 23 ++++++ include/linux/mm.h | 1 include/linux/scatterlist.h | 91 ++++++++++++++++++++++-- include/linux/swiotlb.h | 4 + init/Kconfig | 13 +++ kernel/power/block_io.c | 2 - lib/dma-debug.c | 10 ++- lib/iov_iter.c | 22 +++--- lib/swiotlb.c | 20 ++++- mm/Makefile | 1 mm/page_io.c | 10 +-- mm/pfn.c | 98 ++++++++++++++++++++++++++ net/ceph/messenger.c | 2 - 117 files changed, 1003 insertions(+), 391 deletions(-) create mode 100644 include/asm-generic/pfn.h create mode 100644 mm/pfn.c -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
