summaryrefslogtreecommitdiff
path: root/arch/powerpc/kvm/e500.h
diff options
context:
space:
mode:
authorDan Williams <dan.j.williams@intel.com>2016-01-16 03:56:11 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-16 04:56:32 +0300
commitba049e93aef7e8c571567088b1b73f4f5b99272a (patch)
treead6c02eca447f57f5787a5357290895e68e9463e /arch/powerpc/kvm/e500.h
parent16da306849d0335af7c353ec14121cf422433d33 (diff)
downloadlinux-ba049e93aef7e8c571567088b1b73f4f5b99272a.tar.xz
kvm: rename pfn_t to kvm_pfn_t
To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/powerpc/kvm/e500.h')
-rw-r--r--arch/powerpc/kvm/e500.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/kvm/e500.h b/arch/powerpc/kvm/e500.h
index 72920bed3ac6..94f04fcb373e 100644
--- a/arch/powerpc/kvm/e500.h
+++ b/arch/powerpc/kvm/e500.h
@@ -41,7 +41,7 @@ enum vcpu_ftr {
#define E500_TLB_MAS2_ATTR (0x7f)
struct tlbe_ref {
- pfn_t pfn; /* valid only for TLB0, except briefly */
+ kvm_pfn_t pfn; /* valid only for TLB0, except briefly */
unsigned int flags; /* E500_TLB_* */
};