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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-08 23:35:59 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-08 23:35:59 +0200 |
commit | 12f03ee606914317e7e6a0815e53a48205c31dae (patch) | |
tree | f8579bf77d29b3921e1877e0ae12ec65b5ebc738 /kernel/resource.c | |
parent | Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/k... (diff) | |
parent | libnvdimm, pmem: direct map legacy pmem by default (diff) | |
download | linux-12f03ee606914317e7e6a0815e53a48205c31dae.tar.xz linux-12f03ee606914317e7e6a0815e53a48205c31dae.zip |
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 'kernel/resource.c')
-rw-r--r-- | kernel/resource.c | 61 |
1 files changed, 36 insertions, 25 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index fed052a1bc9f..f150dbbe6f62 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -492,40 +492,51 @@ int __weak page_is_ram(unsigned long pfn) } EXPORT_SYMBOL_GPL(page_is_ram); -/* - * Search for a resouce entry that fully contains the specified region. - * If found, return 1 if it is RAM, 0 if not. - * If not found, or region is not fully contained, return -1 +/** + * region_intersects() - determine intersection of region with known resources + * @start: region start address + * @size: size of region + * @name: name of resource (in iomem_resource) * - * Used by the ioremap functions to ensure the user is not remapping RAM and is - * a vast speed up over walking through the resource table page by page. + * Check if the specified region partially overlaps or fully eclipses a + * resource identified by @name. Return REGION_DISJOINT if the region + * does not overlap @name, return REGION_MIXED if the region overlaps + * @type and another resource, and return REGION_INTERSECTS if the + * region overlaps @type and no other defined resource. Note, that + * REGION_INTERSECTS is also returned in the case when the specified + * region overlaps RAM and undefined memory holes. + * + * region_intersect() is used by memory remapping functions to ensure + * the user is not remapping RAM and is a vast speed up over walking + * through the resource table page by page. */ -int region_is_ram(resource_size_t start, unsigned long size) +int region_intersects(resource_size_t start, size_t size, const char *name) { - struct resource *p; - resource_size_t end = start + size - 1; unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY; - const char *name = "System RAM"; - int ret = -1; + resource_size_t end = start + size - 1; + int type = 0; int other = 0; + struct resource *p; read_lock(&resource_lock); for (p = iomem_resource.child; p ; p = p->sibling) { - if (p->end < start) - continue; - - if (p->start <= start && end <= p->end) { - /* resource fully contains region */ - if ((p->flags != flags) || strcmp(p->name, name)) - ret = 0; - else - ret = 1; - break; - } - if (end < p->start) - break; /* not found */ + bool is_type = strcmp(p->name, name) == 0 && p->flags == flags; + + if (start >= p->start && start <= p->end) + is_type ? type++ : other++; + if (end >= p->start && end <= p->end) + is_type ? type++ : other++; + if (p->start >= start && p->end <= end) + is_type ? type++ : other++; } read_unlock(&resource_lock); - return ret; + + if (other == 0) + return type ? REGION_INTERSECTS : REGION_DISJOINT; + + if (type) + return REGION_MIXED; + + return REGION_DISJOINT; } void __weak arch_remove_reservations(struct resource *avail) |