From 185c1a489f873cb71520fc089401e02dbf302dcd Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Thu, 21 Dec 2023 15:04:23 -0700 Subject: cxl: Check qos_class validity on memdev probe Add a check to make sure the qos_class for the device will match one of the root decoders qos_class. If no match is found, then the qos_class for the device is set to invalid. Also add a check to ensure that the device's host bridge matches to one of the root decoder's downstream targets. Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/170319626313.2212653.9021004640856081917.stgit@djiang5-mobl3 Signed-off-by: Dan Williams --- drivers/cxl/core/cdat.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) (limited to 'drivers/cxl') diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c index 6189d967f399..cd84d87f597a 100644 --- a/drivers/cxl/core/cdat.c +++ b/drivers/cxl/core/cdat.c @@ -272,6 +272,108 @@ static void cxl_memdev_set_qos_class(struct cxl_dev_state *cxlds, devm_add_action_or_reset(&cxlds->cxlmd->dev, free_perf_ents, mds); } +static int match_cxlrd_qos_class(struct device *dev, void *data) +{ + int dev_qos_class = *(int *)data; + struct cxl_root_decoder *cxlrd; + + if (!is_root_decoder(dev)) + return 0; + + cxlrd = to_cxl_root_decoder(dev); + if (cxlrd->qos_class == CXL_QOS_CLASS_INVALID) + return 0; + + if (cxlrd->qos_class == dev_qos_class) + return 1; + + return 0; +} + +static void cxl_qos_match(struct cxl_port *root_port, + struct list_head *work_list, + struct list_head *discard_list) +{ + struct cxl_dpa_perf *dpa_perf, *n; + + list_for_each_entry_safe(dpa_perf, n, work_list, list) { + int rc; + + if (dpa_perf->qos_class == CXL_QOS_CLASS_INVALID) + return; + + rc = device_for_each_child(&root_port->dev, + (void *)&dpa_perf->qos_class, + match_cxlrd_qos_class); + if (!rc) + list_move_tail(&dpa_perf->list, discard_list); + } +} + +static int match_cxlrd_hb(struct device *dev, void *data) +{ + struct device *host_bridge = data; + struct cxl_switch_decoder *cxlsd; + struct cxl_root_decoder *cxlrd; + unsigned int seq; + + if (!is_root_decoder(dev)) + return 0; + + cxlrd = to_cxl_root_decoder(dev); + cxlsd = &cxlrd->cxlsd; + + do { + seq = read_seqbegin(&cxlsd->target_lock); + for (int i = 0; i < cxlsd->nr_targets; i++) { + if (host_bridge == cxlsd->target[i]->dport_dev) + return 1; + } + } while (read_seqretry(&cxlsd->target_lock, seq)); + + return 0; +} + +static void discard_dpa_perf(struct list_head *list) +{ + struct cxl_dpa_perf *dpa_perf, *n; + + list_for_each_entry_safe(dpa_perf, n, list, list) { + list_del(&dpa_perf->list); + kfree(dpa_perf); + } +} +DEFINE_FREE(dpa_perf, struct list_head *, if (!list_empty(_T)) discard_dpa_perf(_T)) + +static int cxl_qos_class_verify(struct cxl_memdev *cxlmd) +{ + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds); + struct cxl_port *root_port __free(put_device) = NULL; + LIST_HEAD(__discard); + struct list_head *discard __free(dpa_perf) = &__discard; + int rc; + + root_port = find_cxl_root(cxlmd->endpoint); + if (!root_port) + return -ENODEV; + + /* Check that the QTG IDs are all sane between end device and root decoders */ + cxl_qos_match(root_port, &mds->ram_perf_list, discard); + cxl_qos_match(root_port, &mds->pmem_perf_list, discard); + + /* Check to make sure that the device's host bridge is under a root decoder */ + rc = device_for_each_child(&root_port->dev, + (void *)cxlmd->endpoint->host_bridge, + match_cxlrd_hb); + if (!rc) { + list_splice_tail_init(&mds->ram_perf_list, discard); + list_splice_tail_init(&mds->pmem_perf_list, discard); + } + + return rc; +} + static void discard_dsmas(struct xarray *xa) { unsigned long index; @@ -310,6 +412,7 @@ void cxl_endpoint_parse_cdat(struct cxl_port *port) } cxl_memdev_set_qos_class(cxlds, dsmas_xa); + cxl_qos_class_verify(cxlmd); } EXPORT_SYMBOL_NS_GPL(cxl_endpoint_parse_cdat, CXL); -- cgit v1.2.3-58-ga151