[PATCH v9 25/27] cxl: add function for obtaining region range

alejandro.lucero-palau
2024-12-30T21:45:40Z

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 b3a68c1d0652..26a84f6f9fb5 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -2677,6 +2677,21 @@ 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 f28873a17443..0fd65d941bd8 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -921,6 +921,7 @@ 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 19f3eef44535..053722ea3e6c 100644
--- a/include/cxl/cxl.h
+++ b/include/cxl/cxl.h
@@ -68,4 +68,6 @@ 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