[RFC V2 01/18] dev_dax_iomap: Move dax_pgoff_to_phys() from device.c to bus.c

[John Groves <John@Groves.net>]

No changes to the function - just moved it.

dev_dax_iomap needs to call this function from
drivers/dax/bus.c.

drivers/dax/bus.c can't call functions in drivers/dax/device.c -
that creates a circular linkage dependency - but device.c can
call functions in bus.c. Also exports dax_pgoff_to_phys() since
both bus.c and device.c now call it.

Signed-off-by: John Groves <john@groves.net>
---
 drivers/dax/bus.c    | 24 ++++++++++++++++++++++++
 drivers/dax/device.c | 23 -----------------------
 2 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index fde29e0ad68b..9d9a4ae7bbc0 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1417,6 +1417,30 @@ static const struct device_type dev_dax_type = {
 	.groups = dax_attribute_groups,
 };
 
+/* see "strong" declaration in tools/testing/nvdimm/dax-dev.c  */
+__weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
+			      unsigned long size)
+{
+	int i;
+
+	for (i = 0; i < dev_dax->nr_range; i++) {
+		struct dev_dax_range *dax_range = &dev_dax->ranges[i];
+		struct range *range = &dax_range->range;
+		unsigned long long pgoff_end;
+		phys_addr_t phys;
+
+		pgoff_end = dax_range->pgoff + PHYS_PFN(range_len(range)) - 1;
+		if (pgoff < dax_range->pgoff || pgoff > pgoff_end)
+			continue;
+		phys = PFN_PHYS(pgoff - dax_range->pgoff) + range->start;
+		if (phys + size - 1 <= range->end)
+			return phys;
+		break;
+	}
+	return -1;
+}
+EXPORT_SYMBOL_GPL(dax_pgoff_to_phys);
+
 static struct dev_dax *__devm_create_dev_dax(struct dev_dax_data *data)
 {
 	struct dax_region *dax_region = data->dax_region;
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 6d74e62bbee0..29f61771fef0 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -50,29 +50,6 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
 	return 0;
 }
 
-/* see "strong" declaration in tools/testing/nvdimm/dax-dev.c */
-__weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
-		unsigned long size)
-{
-	int i;
-
-	for (i = 0; i < dev_dax->nr_range; i++) {
-		struct dev_dax_range *dax_range = &dev_dax->ranges[i];
-		struct range *range = &dax_range->range;
-		unsigned long long pgoff_end;
-		phys_addr_t phys;
-
-		pgoff_end = dax_range->pgoff + PHYS_PFN(range_len(range)) - 1;
-		if (pgoff < dax_range->pgoff || pgoff > pgoff_end)
-			continue;
-		phys = PFN_PHYS(pgoff - dax_range->pgoff) + range->start;
-		if (phys + size - 1 <= range->end)
-			return phys;
-		break;
-	}
-	return -1;
-}
-
 static void dax_set_mapping(struct vm_fault *vmf, pfn_t pfn,
 			      unsigned long fault_size)
 {
-- 
2.49.0