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authorLinus Torvalds <torvalds@linux-foundation.org>2020-04-08 21:03:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-08 21:03:40 -0700
commit9b06860d7c1f1f4cb7d70f92e47dfa4a91bd5007 (patch)
tree120882e574394ce3b11bd491533613b4488fae45 /mm/memremap.c
parent0906d8b975ff713cfb55328e4f3bf6de5967415e (diff)
parentf6d2b802f80d0ca89ee1f51c1781b3f79cdb25d5 (diff)
Merge tag 'libnvdimm-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm and dax updates from Dan Williams: "There were multiple touches outside of drivers/nvdimm/ this round to add cross arch compatibility to the devm_memremap_pages() interface, enhance numa information for persistent memory ranges, and add a zero_page_range() dax operation. This cycle I switched from the patchwork api to Konstantin's b4 script for collecting tags (from x86, PowerPC, filesystem, and device-mapper folks), and everything looks to have gone ok there. This has all appeared in -next with no reported issues. Summary: - Add support for region alignment configuration and enforcement to fix compatibility across architectures and PowerPC page size configurations. - Introduce 'zero_page_range' as a dax operation. This facilitates filesystem-dax operation without a block-device. - Introduce phys_to_target_node() to facilitate drivers that want to know resulting numa node if a given reserved address range was onlined. - Advertise a persistence-domain for of_pmem and papr_scm. The persistence domain indicates where cpu-store cycles need to reach in the platform-memory subsystem before the platform will consider them power-fail protected. - Promote numa_map_to_online_node() to a cross-kernel generic facility. - Save x86 numa information to allow for node-id lookups for reserved memory ranges, deploy that capability for the e820-pmem driver. - Pick up some miscellaneous minor fixes, that missed v5.6-final, including a some smatch reports in the ioctl path and some unit test compilation fixups. - Fixup some flexible-array declarations" * tag 'libnvdimm-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (29 commits) dax: Move mandatory ->zero_page_range() check in alloc_dax() dax,iomap: Add helper dax_iomap_zero() to zero a range dax: Use new dax zero page method for zeroing a page dm,dax: Add dax zero_page_range operation s390,dcssblk,dax: Add dax zero_page_range operation to dcssblk driver dax, pmem: Add a dax operation zero_page_range pmem: Add functions for reading/writing page to/from pmem libnvdimm: Update persistence domain value for of_pmem and papr_scm device tools/test/nvdimm: Fix out of tree build libnvdimm/region: Fix build error libnvdimm/region: Replace zero-length array with flexible-array member libnvdimm/label: Replace zero-length array with flexible-array member ACPI: NFIT: Replace zero-length array with flexible-array member libnvdimm/region: Introduce an 'align' attribute libnvdimm/region: Introduce NDD_LABELING libnvdimm/namespace: Enforce memremap_compat_align() libnvdimm/pfn: Prevent raw mode fallback if pfn-infoblock valid libnvdimm: Out of bounds read in __nd_ioctl() acpi/nfit: improve bounds checking for 'func' mm/memremap_pages: Introduce memremap_compat_align() ...
Diffstat (limited to 'mm/memremap.c')
-rw-r--r--mm/memremap.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/mm/memremap.c b/mm/memremap.c
index 9b2c97ceb775..bbf457c4f166 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -7,6 +7,7 @@
#include <linux/mm.h>
#include <linux/pfn_t.h>
#include <linux/swap.h>
+#include <linux/mmzone.h>
#include <linux/swapops.h>
#include <linux/types.h>
#include <linux/wait_bit.h>
@@ -14,6 +15,28 @@
static DEFINE_XARRAY(pgmap_array);
+/*
+ * The memremap() and memremap_pages() interfaces are alternately used
+ * to map persistent memory namespaces. These interfaces place different
+ * constraints on the alignment and size of the mapping (namespace).
+ * memremap() can map individual PAGE_SIZE pages. memremap_pages() can
+ * only map subsections (2MB), and at least one architecture (PowerPC)
+ * the minimum mapping granularity of memremap_pages() is 16MB.
+ *
+ * The role of memremap_compat_align() is to communicate the minimum
+ * arch supported alignment of a namespace such that it can freely
+ * switch modes without violating the arch constraint. Namely, do not
+ * allow a namespace to be PAGE_SIZE aligned since that namespace may be
+ * reconfigured into a mode that requires SUBSECTION_SIZE alignment.
+ */
+#ifndef CONFIG_ARCH_HAS_MEMREMAP_COMPAT_ALIGN
+unsigned long memremap_compat_align(void)
+{
+ return SUBSECTION_SIZE;
+}
+EXPORT_SYMBOL_GPL(memremap_compat_align);
+#endif
+
#ifdef CONFIG_DEV_PAGEMAP_OPS
DEFINE_STATIC_KEY_FALSE(devmap_managed_key);
EXPORT_SYMBOL(devmap_managed_key);