[PATCH v10 24/26] cxl: add function for obtaining region range

[<alucerop@amd.com>]

From: Alejandro Lucero <alucerop@amd.com>

A CXL region struct contains the physical address to work with.

Add a function for getting the cxl region range to be used for mapping
such memory range.

Signed-off-by: Alejandro Lucero <alucerop@amd.com>
Reviewed-by: Zhi Wang <zhiw@nvidia.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/cxl/core/region.c | 15 +++++++++++++++
 drivers/cxl/cxl.h         |  1 +
 include/cxl/cxl.h         |  2 ++
 3 files changed, 18 insertions(+)

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 742c03e983d5..608160d3a308 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -2702,6 +2702,21 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd,
 	return ERR_PTR(rc);
 }
 
+int cxl_get_region_range(struct cxl_region *region, struct range *range)
+{
+	if (WARN_ON_ONCE(!region))
+		return -ENODEV;
+
+	if (!region->params.res)
+		return -ENOSPC;
+
+	range->start = region->params.res->start;
+	range->end = region->params.res->end;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_get_region_range, "CXL");
+
 static ssize_t __create_region_show(struct cxl_root_decoder *cxlrd, char *buf)
 {
 	return sysfs_emit(buf, "region%u\n", atomic_read(&cxlrd->region_id));
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 4f7aaffa04b1..dd2c828431aa 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -893,6 +893,7 @@ void cxl_coordinates_combine(struct access_coordinate *out,
 
 bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);
 
+int cxl_get_region_range(struct cxl_region *region, struct range *range);
 /*
  * Unit test builds overrides this to __weak, find the 'strong' version
  * of these symbols in tools/testing/cxl/.
diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
index 6a0625476f24..317dc8cddfcd 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -99,4 +99,6 @@ struct cxl_region *cxl_create_region(struct cxl_root_decoder *cxlrd,
 				     bool no_dax);
 
 int cxl_accel_region_detach(struct cxl_endpoint_decoder *cxled);
+struct range;
+int cxl_get_region_range(struct cxl_region *region, struct range *range);
 #endif
-- 
2.17.1