[PATCH v2 14/15] cxl: add function for obtaining params from a region

alejandro.lucero-palau
2024-07-15T17:29:13Z

From: Alejandro Lucero <alucerop@amd.com>

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

Add a function for given a opaque cxl region struct returns the params
to be used for mapping such memory range.

Signed-off-by: Alejandro Lucero <alucerop@amd.com>
---
drivers/cxl/core/region.c | 16 ++++++++++++++++
drivers/cxl/cxl.h | 3 +++
include/linux/cxl_accel_mem.h | 2 ++
3 files changed, 21 insertions(+)

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index c8fc14ac437e..9ff10923e9fc 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -3345,6 +3345,22 @@ static int devm_cxl_add_dax_region(struct cxl_region *cxlr)
return rc;
}

+int cxl_accel_get_region_params(struct cxl_region *region,
+ resource_size_t *start, resource_size_t *end)
+{
+ if (!region)
+ return -ENODEV;
+
+ if (!region->params.res) {
+ return -ENODEV;
+ }
+ *start = region->params.res->start;
+ *end = region->params.res->end;
+
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_accel_get_region_params, CXL);
+
static int match_root_decoder_by_range(struct device *dev, void *data)
{
struct range *r1, *r2 = data;
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 1bf3b74ff959..b4c4c4455ef1 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -906,6 +906,9 @@ void cxl_coordinates_combine(struct access_coordinate *out,
bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);

int cxl_region_detach(struct cxl_endpoint_decoder *cxled);
+
+int cxl_accel_get_region_params(struct cxl_region *region,
+ resource_size_t *start, resource_size_t *end);
/*
* Unit test builds overrides this to __weak, find the 'strong' version
* of these symbols in tools/testing/cxl/.
diff --git a/include/linux/cxl_accel_mem.h b/include/linux/cxl_accel_mem.h
index a5f9ffc24509..5d715eea6e91 100644
--- a/include/linux/cxl_accel_mem.h
+++ b/include/linux/cxl_accel_mem.h
@@ -53,4 +53,6 @@ struct cxl_region *cxl_create_region(struct cxl_root_decoder *cxlrd,
int ways);

int cxl_region_detach(struct cxl_endpoint_decoder *cxled);
+int cxl_accel_get_region_params(struct cxl_region *region,
+ resource_size_t *start, resource_size_t *end);
#endif
--
2.17.1