libnvdimm, pmem: 'struct page' for pmem

Enable the pmem driver to handle PFN device instances.  Attaching a pmem
namespace to a pfn device triggers the driver to allocate and initialize
struct page entries for pmem.  Memory capacity for this allocation comes
exclusively from RAM for now which is suitable for low PMEM to RAM
ratios.  This mechanism will be expanded later for setting an "allocate
from PMEM" policy.

Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 14 insertions, 0 deletions

diff --git a/tools/testing/nvdimm/Kbuild b/tools/testing/nvdimm/Kbuild
index 99e70f0729be..38b00ecb2ed5 100644
--- a/tools/testing/nvdimm/Kbuild
+++ b/tools/testing/nvdimm/Kbuild
@@ -2,6 +2,7 @@ ldflags-y += --wrap=ioremap_wc
 ldflags-y += --wrap=memremap
 ldflags-y += --wrap=devm_ioremap_nocache
 ldflags-y += --wrap=devm_memremap
+ldflags-y += --wrap=devm_memunmap
 ldflags-y += --wrap=ioremap_nocache
 ldflags-y += --wrap=iounmap
 ldflags-y += --wrap=memunmap
diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c
index 179d2289f3a8..b7251314bbc0 100644
--- a/tools/testing/nvdimm/test/iomap.c
+++ b/tools/testing/nvdimm/test/iomap.c
@@ -108,6 +108,19 @@ void *__wrap_memremap(resource_size_t offset, size_t size,
 }
 EXPORT_SYMBOL(__wrap_memremap);
 
+void __wrap_devm_memunmap(struct device *dev, void *addr)
+{
+        struct nfit_test_resource *nfit_res;
+
+        rcu_read_lock();
+        nfit_res = get_nfit_res((unsigned long) addr);
+        rcu_read_unlock();
+        if (nfit_res)
+                return;
+        return devm_memunmap(dev, addr);
+}
+EXPORT_SYMBOL(__wrap_devm_memunmap);
+
 void __iomem *__wrap_ioremap_nocache(resource_size_t offset, unsigned long size)
 {
         return __nfit_test_ioremap(offset, size, ioremap_nocache);