device-dax: make pgmap optional for instance creation

The passed in dev_pagemap is only required in the pmem case as the
libnvdimm core may have reserved a vmem_altmap for dev_memremap_pages() to
place the memmap in pmem directly.  In the hmem case there is no agent
reserving an altmap so it can all be handled by a core internal default.

Pass the resource range via a new @range property of 'struct
dev_dax_data'.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Brice Goglin <Brice.Goglin@inria.fr>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jia He <justin.he@arm.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hulk Robot <hulkci@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Yan <yanaijie@huawei.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/159643099958.4062302.10379230791041872886.stgit@dwillia2-desk3.amr.corp.intel.com
Link: https://lkml.kernel.org/r/160106110513.30709.4303239334850606031.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 9 deletions

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index c528b725789b..287cf0a3db23 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -55,12 +55,12 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
 		unsigned long size)
 {
-	struct resource *res = &dev_dax->region->res;
+	struct range *range = &dev_dax->range;
 	phys_addr_t phys;
 
-	phys = pgoff * PAGE_SIZE + res->start;
-	if (phys >= res->start && phys <= res->end) {
-		if (phys + size - 1 <= res->end)
+	phys = pgoff * PAGE_SIZE + range->start;
+	if (phys >= range->start && phys <= range->end) {
+		if (phys + size - 1 <= range->end)
 			return phys;
 	}
 
@@ -396,21 +396,31 @@ int dev_dax_probe(struct device *dev)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
 	struct dax_device *dax_dev = dev_dax->dax_dev;
-	struct resource *res = &dev_dax->region->res;
+	struct range *range = &dev_dax->range;
+	struct dev_pagemap *pgmap;
 	struct inode *inode;
 	struct cdev *cdev;
 	void *addr;
 	int rc;
 
 	/* 1:1 map region resource range to device-dax instance range */
-	if (!devm_request_mem_region(dev, res->start, resource_size(res),
+	if (!devm_request_mem_region(dev, range->start, range_len(range),
 				dev_name(dev))) {
-		dev_warn(dev, "could not reserve region %pR\n", res);
+		dev_warn(dev, "could not reserve range: %#llx - %#llx\n",
+				range->start, range->end);
 		return -EBUSY;
 	}
 
-	dev_dax->pgmap.type = MEMORY_DEVICE_GENERIC;
-	addr = devm_memremap_pages(dev, &dev_dax->pgmap);
+	pgmap = dev_dax->pgmap;
+	if (!pgmap) {
+		pgmap = devm_kzalloc(dev, sizeof(*pgmap), GFP_KERNEL);
+		if (!pgmap)
+			return -ENOMEM;
+		pgmap->res.start = range->start;
+		pgmap->res.end = range->end;
+	}
+	pgmap->type = MEMORY_DEVICE_GENERIC;
+	addr = devm_memremap_pages(dev, pgmap);
 	if (IS_ERR(addr))
 		return PTR_ERR(addr);