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>

6 files changed, 11 insertions, 11 deletions

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 099c79d8c160..638c6d9be9e0 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -366,7 +366,7 @@ int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvmppc_core_prepare_to_enter);
 
-pfn_t kvmppc_gpa_to_pfn(struct kvm_vcpu *vcpu, gpa_t gpa, bool writing,
+kvm_pfn_t kvmppc_gpa_to_pfn(struct kvm_vcpu *vcpu, gpa_t gpa, bool writing,
 			bool *writable)
 {
 	ulong mp_pa = vcpu->arch.magic_page_pa & KVM_PAM;
@@ -379,9 +379,9 @@ pfn_t kvmppc_gpa_to_pfn(struct kvm_vcpu *vcpu, gpa_t gpa, bool writing,
 	gpa &= ~0xFFFULL;
 	if (unlikely(mp_pa) && unlikely((gpa & KVM_PAM) == mp_pa)) {
 		ulong shared_page = ((ulong)vcpu->arch.shared) & PAGE_MASK;
-		pfn_t pfn;
+		kvm_pfn_t pfn;
 
-		pfn = (pfn_t)virt_to_phys((void*)shared_page) >> PAGE_SHIFT;
+		pfn = (kvm_pfn_t)virt_to_phys((void*)shared_page) >> PAGE_SHIFT;
 		get_page(pfn_to_page(pfn));
 		if (writable)
 			*writable = true;
diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c
index d5c9bfeb0c9c..55c4d51ea3e2 100644
--- a/arch/powerpc/kvm/book3s_32_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_32_mmu_host.c
@@ -142,7 +142,7 @@ extern char etext[];
 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
 			bool iswrite)
 {
-	pfn_t hpaddr;
+	kvm_pfn_t hpaddr;
 	u64 vpn;
 	u64 vsid;
 	struct kvmppc_sid_map *map;
diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c
index 79ad35abd196..913cd2198fa6 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_host.c
@@ -83,7 +83,7 @@ int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
 			bool iswrite)
 {
 	unsigned long vpn;
-	pfn_t hpaddr;
+	kvm_pfn_t hpaddr;
 	ulong hash, hpteg;
 	u64 vsid;
 	int ret;
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_* */
 };
 
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 34c43fff4adb..b0333cc737dd 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -163,9 +163,9 @@ void kvmppc_map_magic(struct kvm_vcpu *vcpu)
 	struct kvm_book3e_206_tlb_entry magic;
 	ulong shared_page = ((ulong)vcpu->arch.shared) & PAGE_MASK;
 	unsigned int stid;
-	pfn_t pfn;
+	kvm_pfn_t pfn;
 
-	pfn = (pfn_t)virt_to_phys((void *)shared_page) >> PAGE_SHIFT;
+	pfn = (kvm_pfn_t)virt_to_phys((void *)shared_page) >> PAGE_SHIFT;
 	get_page(pfn_to_page(pfn));
 
 	preempt_disable();
@@ -246,7 +246,7 @@ static inline int tlbe_is_writable(struct kvm_book3e_206_tlb_entry *tlbe)
 
 static inline void kvmppc_e500_ref_setup(struct tlbe_ref *ref,
 					 struct kvm_book3e_206_tlb_entry *gtlbe,
-					 pfn_t pfn, unsigned int wimg)
+					 kvm_pfn_t pfn, unsigned int wimg)
 {
 	ref->pfn = pfn;
 	ref->flags = E500_TLB_VALID;
@@ -309,7 +309,7 @@ static void kvmppc_e500_setup_stlbe(
 	int tsize, struct tlbe_ref *ref, u64 gvaddr,
 	struct kvm_book3e_206_tlb_entry *stlbe)
 {
-	pfn_t pfn = ref->pfn;
+	kvm_pfn_t pfn = ref->pfn;
 	u32 pr = vcpu->arch.shared->msr & MSR_PR;
 
 	BUG_ON(!(ref->flags & E500_TLB_VALID));
diff --git a/arch/powerpc/kvm/trace_pr.h b/arch/powerpc/kvm/trace_pr.h
index 810507cb688a..d44f324184fb 100644
--- a/arch/powerpc/kvm/trace_pr.h
+++ b/arch/powerpc/kvm/trace_pr.h
@@ -30,7 +30,7 @@ TRACE_EVENT(kvm_book3s_reenter,
 #ifdef CONFIG_PPC_BOOK3S_64
 
 TRACE_EVENT(kvm_book3s_64_mmu_map,
-	TP_PROTO(int rflags, ulong hpteg, ulong va, pfn_t hpaddr,
+	TP_PROTO(int rflags, ulong hpteg, ulong va, kvm_pfn_t hpaddr,
 		 struct kvmppc_pte *orig_pte),
 	TP_ARGS(rflags, hpteg, va, hpaddr, orig_pte),