Commit fae8817a authored by Dan Williams's avatar Dan Williams
Browse files

cxl/mem: Fix memory device capacity probing 



The CXL Identify Memory Device output payload emits capacity in 256MB
units. The driver is treating the capacity field as bytes. This was
missed because QEMU reports bytes when it should report bytes / 256MB.

Fixes: 8adaf747 ("cxl/mem: Find device capabilities")
Reviewed-by: default avatarVishal Verma <vishal.l.verma@intel.com>
Cc: Ben Widawsky <ben.widawsky@intel.com>
Link: https://lore.kernel.org/r/161862021044.3259705.7008520073059739760.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent b21bb4cd

drivers/cxl/mem.c

+5 −2
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#include <linux/security.h>

#include <linux/debugfs.h>

#include <linux/module.h>

#include <linux/sizes.h>

#include <linux/mutex.h>

#include <linux/cdev.h>

#include <linux/idr.h>
@@ -1419,6 +1420,7 @@ static int cxl_mem_enumerate_cmds(struct cxl_mem *cxlm) 
 */

static int cxl_mem_identify(struct cxl_mem *cxlm)

{

	/* See CXL 2.0 Table 175 Identify Memory Device Output Payload */

	struct cxl_mbox_identify {

		char fw_revision[0x10];

		__le64 total_capacity;
@@ -1447,10 +1449,11 @@ static int cxl_mem_identify(struct cxl_mem *cxlm) 
	 * For now, only the capacity is exported in sysfs

	 */

	cxlm->ram_range.start = 0;

	cxlm->ram_range.end = le64_to_cpu(id.volatile_capacity) - 1;

	cxlm->ram_range.end = le64_to_cpu(id.volatile_capacity) * SZ_256M - 1;



	cxlm->pmem_range.start = 0;

	cxlm->pmem_range.end = le64_to_cpu(id.persistent_capacity) - 1;

	cxlm->pmem_range.end =

		le64_to_cpu(id.persistent_capacity) * SZ_256M - 1;



	memcpy(cxlm->firmware_version, id.fw_revision, sizeof(id.fw_revision));