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author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-03 16:21:05 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-03 16:21:05 -0700 |
commit | 7367539ad4b0f8f9b396baf02110962333719a48 (patch) | |
tree | d0cdada641cf176f05c409f74a23899c2151a709 | |
parent | ddb4c3f25b7b95df3d6932db0b379d768a6ebdf7 (diff) | |
parent | 5d211c7090590033581175d6405ae40917ca3a06 (diff) | |
download | linux-stable-7367539ad4b0f8f9b396baf02110962333719a48.tar.gz linux-stable-7367539ad4b0f8f9b396baf02110962333719a48.tar.bz2 linux-stable-7367539ad4b0f8f9b396baf02110962333719a48.zip |
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
-rw-r--r-- | drivers/cxl/core/port.c | 15 | ||||
-rw-r--r-- | tools/testing/cxl/test/cxl.c | 7 |
2 files changed, 21 insertions, 1 deletions
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 762783bb091a..887ed6e358fb 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -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, @@ -2197,6 +2198,7 @@ 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; @@ -2204,6 +2206,13 @@ int cxl_endpoint_get_perf_coordinates(struct cxl_port *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 * latency of the CXL link from the current device/port to the connected @@ -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; diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c index 61c69297e797..3482248aa344 100644 --- a/tools/testing/cxl/test/cxl.c +++ b/tools/testing/cxl/test/cxl.c @@ -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 = { |