[V3] cxl/mem: Adjust ram/pmem range to represent DPA ranges

Commit Message

Ira Weiny June 21, 2021, 7:54 p.m. UTC

From: Ira Weiny <[e-mail]>

Table 176 of the CXL spec defines the volatile DPA range to be 0 to
Volatile memory size.  It further defines the persistent DPA range to
follow directly after the end of the Volatile DPA through the persistent
memory size.  Essentially

Volatile DPA range   = [0, Volatile size)
Persistent DPA range = [Volatile size, Volatile size + Persistent size)

Adjust the pmem_range start to reflect this and remove the TODO.

Reviewed-by: Jonathan Cameron <[e-mail]>
Signed-off-by: Ira Weiny <[e-mail]>

---
For some reason I fixed this but failed to send it out...

Changes for V3
	Jonathan -- Clean up commit message

---
 drivers/cxl/pci.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

Patch

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 3c8b7aa8c273..592374baa005 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -1633,8 +1633,9 @@  static int cxl_mem_create_range_info(struct cxl_mem *cxlm)
 	if (cxlm->partition_align_bytes == 0) {
 		cxlm->ram_range.start = 0;
 		cxlm->ram_range.end = cxlm->volatile_only_bytes - 1;
-		cxlm->pmem_range.start = 0;
-		cxlm->pmem_range.end = cxlm->persistent_only_bytes - 1;
+		cxlm->pmem_range.start = cxlm->volatile_only_bytes;
+		cxlm->pmem_range.end = cxlm->volatile_only_bytes +
+					cxlm->persistent_only_bytes - 1;
 		return 0;
 	}
 
@@ -1658,15 +1659,12 @@  static int cxl_mem_create_range_info(struct cxl_mem *cxlm)
 			cxlm->next_volatile_bytes,
 			cxlm->next_persistent_bytes);
 
-	/*
-	 * TODO: enumerate DPA map, as 'ram' and 'pmem' do not alias.
-	 * For now, only the capacity is exported in sysfs
-	 */
 	cxlm->ram_range.start = 0;
 	cxlm->ram_range.end = cxlm->active_volatile_bytes - 1;
 
-	cxlm->pmem_range.start = 0;
-	cxlm->pmem_range.end = cxlm->active_persistent_bytes - 1;
+	cxlm->pmem_range.start = cxlm->active_volatile_bytes;
+	cxlm->pmem_range.end = cxlm->active_volatile_bytes +
+				cxlm->active_persistent_bytes - 1;
 
 	return 0;
 }