summaryrefslogtreecommitdiff
path: root/mm
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-09 00:35:59 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-09 00:35:59 +0300
commit12f03ee606914317e7e6a0815e53a48205c31dae (patch)
treef8579bf77d29b3921e1877e0ae12ec65b5ebc738 /mm
parentd9241b22b58e012f26dd2244508d9f4837402af0 (diff)
parent004f1afbe199e6ab20805b95aefd83ccd24bc5c7 (diff)
downloadlinux-12f03ee606914317e7e6a0815e53a48205c31dae.tar.xz
Merge tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Dan Williams: "This update has successfully completed a 0day-kbuild run and has appeared in a linux-next release. The changes outside of the typical drivers/nvdimm/ and drivers/acpi/nfit.[ch] paths are related to the removal of IORESOURCE_CACHEABLE, the introduction of memremap(), and the introduction of ZONE_DEVICE + devm_memremap_pages(). Summary: - Introduce ZONE_DEVICE and devm_memremap_pages() as a generic mechanism for adding device-driver-discovered memory regions to the kernel's direct map. This facility is used by the pmem driver to enable pfn_to_page() operations on the page frames returned by DAX ('direct_access' in 'struct block_device_operations'). For now, the 'memmap' allocation for these "device" pages comes from "System RAM". Support for allocating the memmap from device memory will arrive in a later kernel. - Introduce memremap() to replace usages of ioremap_cache() and ioremap_wt(). memremap() drops the __iomem annotation for these mappings to memory that do not have i/o side effects. The replacement of ioremap_cache() with memremap() is limited to the pmem driver to ease merging the api change in v4.3. Completion of the conversion is targeted for v4.4. - Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem driver, update the VFS DAX implementation and PMEM api to provide persistence guarantees for kernel operations on a DAX mapping. - Convert the ACPI NFIT 'BLK' driver to map the block apertures as cacheable to improve performance. - Miscellaneous updates and fixes to libnvdimm including support for issuing "address range scrub" commands, clarifying the optimal 'sector size' of pmem devices, a clarification of the usage of the ACPI '_STA' (status) property for DIMM devices, and other minor fixes" * tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (34 commits) libnvdimm, pmem: direct map legacy pmem by default libnvdimm, pmem: 'struct page' for pmem libnvdimm, pfn: 'struct page' provider infrastructure x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB add devm_memremap_pages mm: ZONE_DEVICE for "device memory" mm: move __phys_to_pfn and __pfn_to_phys to asm/generic/memory_model.h dax: drop size parameter to ->direct_access() nd_blk: change aperture mapping from WC to WB nvdimm: change to use generic kvfree() pmem, dax: have direct_access use __pmem annotation dax: update I/O path to do proper PMEM flushing pmem: add copy_from_iter_pmem() and clear_pmem() pmem, x86: clean up conditional pmem includes pmem: remove layer when calling arch_has_wmb_pmem() pmem, x86: move x86 PMEM API to new pmem.h header libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option pmem: switch to devm_ allocations devres: add devm_memremap libnvdimm, btt: write and validate parent_uuid ...
Diffstat (limited to 'mm')
-rw-r--r--mm/Kconfig17
-rw-r--r--mm/memory_hotplug.c14
-rw-r--r--mm/page_alloc.c3
3 files changed, 31 insertions, 3 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index d4e6495a720f..3a4070f5ab79 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -648,3 +648,20 @@ config DEFERRED_STRUCT_PAGE_INIT
when kswapd starts. This has a potential performance impact on
processes running early in the lifetime of the systemm until kswapd
finishes the initialisation.
+
+config ZONE_DEVICE
+ bool "Device memory (pmem, etc...) hotplug support" if EXPERT
+ default !ZONE_DMA
+ depends on !ZONE_DMA
+ depends on MEMORY_HOTPLUG
+ depends on MEMORY_HOTREMOVE
+ depends on X86_64 #arch_add_memory() comprehends device memory
+
+ help
+ Device memory hotplug support allows for establishing pmem,
+ or other device driver discovered memory regions, in the
+ memmap. This allows pfn_to_page() lookups of otherwise
+ "device-physical" addresses which is needed for using a DAX
+ mapping in an O_DIRECT operation, among other things.
+
+ If FS_DAX is enabled, then say Y.
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 8fd97dac538a..aa992e2df58a 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -778,7 +778,10 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
start = phys_start_pfn << PAGE_SHIFT;
size = nr_pages * PAGE_SIZE;
- ret = release_mem_region_adjustable(&iomem_resource, start, size);
+
+ /* in the ZONE_DEVICE case device driver owns the memory region */
+ if (!is_dev_zone(zone))
+ ret = release_mem_region_adjustable(&iomem_resource, start, size);
if (ret) {
resource_size_t endres = start + size - 1;
@@ -1215,8 +1218,13 @@ static int should_add_memory_movable(int nid, u64 start, u64 size)
return 0;
}
-int zone_for_memory(int nid, u64 start, u64 size, int zone_default)
+int zone_for_memory(int nid, u64 start, u64 size, int zone_default,
+ bool for_device)
{
+#ifdef CONFIG_ZONE_DEVICE
+ if (for_device)
+ return ZONE_DEVICE;
+#endif
if (should_add_memory_movable(nid, start, size))
return ZONE_MOVABLE;
@@ -1265,7 +1273,7 @@ int __ref add_memory(int nid, u64 start, u64 size)
}
/* call arch's memory hotadd */
- ret = arch_add_memory(nid, start, size);
+ ret = arch_add_memory(nid, start, size, false);
if (ret < 0)
goto error;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5b5240b7f642..b401d40cb4fd 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -206,6 +206,9 @@ static char * const zone_names[MAX_NR_ZONES] = {
"HighMem",
#endif
"Movable",
+#ifdef CONFIG_ZONE_DEVICE
+ "Device",
+#endif
};
int min_free_kbytes = 1024;