Commit 7367539a authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'cxl-fixes-6.9-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl 

Pull cxl fix from Dave Jiang:
 "Add missing RCH support for endpoint access_coordinate calculation.

  A late bug was reported by Robert Richter that the Restricted CXL Host
  (RCH) support was missing in the CXL endpoint access_coordinate
  calculation.

  The missing support causes the topology iterator to stumble over a
  NULL pointer and triggers a kernel OOPS on a platform with CXL 1.1
  support.

  The fix bypasses RCH topology as the access_coordinate calculation is
  not necessary since RCH does not support hotplug and the memory region
  exported should be covered by the HMAT table already.

  A unit test is also added to cxl_test to check against future
  regressions on the topology iterator"

* tag 'cxl-fixes-6.9-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
  cxl: Fix cxl_endpoint_get_perf_coordinate() support for RCH
parents ddb4c3f2 5d211c70

drivers/cxl/core/port.c

+14 −1
Original line number Diff line number Diff line
@@ -2184,6 +2184,7 @@ static bool parent_port_is_cxl_root(struct cxl_port *port) 
int cxl_endpoint_get_perf_coordinates(struct cxl_port *port,

				      struct access_coordinate *coord)

{

	struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);

	struct access_coordinate c[] = {

		{

			.read_bandwidth = UINT_MAX,
@@ -2197,12 +2198,20 @@ int cxl_endpoint_get_perf_coordinates(struct cxl_port *port, 
	struct cxl_port *iter = port;

	struct cxl_dport *dport;

	struct pci_dev *pdev;

	struct device *dev;

	unsigned int bw;

	bool is_cxl_root;



	if (!is_cxl_endpoint(port))

		return -EINVAL;



	/*

	 * Skip calculation for RCD. Expectation is HMAT already covers RCD case

	 * since RCH does not support hotplug.

	 */

	if (cxlmd->cxlds->rcd)

		return 0;



	/*

	 * Exit the loop when the parent port of the current iter port is cxl

	 * root. The iterative loop starts at the endpoint and gathers the
@@ -2232,8 +2241,12 @@ int cxl_endpoint_get_perf_coordinates(struct cxl_port *port, 
		return -EINVAL;

	cxl_coordinates_combine(c, c, dport->coord);



	dev = port->uport_dev->parent;

	if (!dev_is_pci(dev))

		return -ENODEV;



	/* Get the calculated PCI paths bandwidth */

	pdev = to_pci_dev(port->uport_dev->parent);

	pdev = to_pci_dev(dev);

	bw = pcie_bandwidth_available(pdev, NULL, NULL, NULL);

	if (bw == 0)

		return -ENXIO;

tools/testing/cxl/test/cxl.c

+7 −0
Original line number Diff line number Diff line
@@ -1001,6 +1001,7 @@ static void mock_cxl_endpoint_parse_cdat(struct cxl_port *port) 
	struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);

	struct cxl_dev_state *cxlds = cxlmd->cxlds;

	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);

	struct access_coordinate ep_c[ACCESS_COORDINATE_MAX];

	struct range pmem_range = {

		.start = cxlds->pmem_res.start,

		.end = cxlds->pmem_res.end,
@@ -1020,6 +1021,12 @@ static void mock_cxl_endpoint_parse_cdat(struct cxl_port *port) 
		dpa_perf_setup(port, &pmem_range, &mds->pmem_perf);



	cxl_memdev_update_perf(cxlmd);



	/*

	 * This function is here to only test the topology iterator. It serves

	 * no other purpose.

	 */

	cxl_endpoint_get_perf_coordinates(port, ep_c);

}



static struct cxl_mock_ops cxl_mock_ops = {