From 98856b2ea3065d8f60e90f423d7707f4a4706ec5 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Fri, 5 Jan 2024 15:07:34 -0700 Subject: [PATCH 1/5] cxl: Introduce put_cxl_root() helper Add a helper function put_cxl_root() to maintain symmetry for find_cxl_root() function instead of relying on open coding of the put_device() in order to dereference the 'struct device' that happens via get_device() in find_cxl_root(). Suggested-by: Robert Richter Reviewed-by: Ira Weiny Signed-off-by: Dave Jiang Reviewed-by: Robert Richter Link: https://lore.kernel.org/r/170449245417.3779673.4566146351673989387.stgit@djiang5-mobl3 Signed-off-by: Dan Williams --- drivers/cxl/core/port.c | 9 +++++++++ drivers/cxl/cxl.h | 3 +++ 2 files changed, 12 insertions(+) diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 8c00fd6be730..64f30d5fe1f6 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -986,6 +986,15 @@ struct cxl_port *find_cxl_root(struct cxl_port *port) } EXPORT_SYMBOL_NS_GPL(find_cxl_root, CXL); +void put_cxl_root(struct cxl_root *cxl_root) +{ + if (!cxl_root) + return; + + put_device(&cxl_root->port.dev); +} +EXPORT_SYMBOL_NS_GPL(put_cxl_root, CXL); + static struct cxl_dport *find_dport(struct cxl_port *port, int id) { struct cxl_dport *dport; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 492dbf63935f..df3db3e43913 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -735,6 +735,9 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct cxl_root *devm_cxl_add_root(struct device *host, const struct cxl_root_ops *ops); struct cxl_port *find_cxl_root(struct cxl_port *port); +void put_cxl_root(struct cxl_root *cxl_root); +DEFINE_FREE(put_cxl_root, struct cxl_root *, if (_T) put_cxl_root(_T)) + int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd); void cxl_bus_rescan(void); void cxl_bus_drain(void); From 44cd71ef7bacdfcf7c3e8a7b13f11a7eba69533d Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Fri, 5 Jan 2024 15:07:40 -0700 Subject: [PATCH 2/5] cxl: Convert find_cxl_root() to return a 'struct cxl_root *' Commit 790815902ec6 ("cxl: Add support for _DSM Function for retrieving QTG ID") introduced 'struct cxl_root', however all usages have been worked indirectly through cxl_port. Refactor code such as find_cxl_root() function to use 'struct cxl_root' directly. Suggested-by: Dan Williams Reviewed-by: Ira Weiny Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/170449246044.3779673.13035770941393418591.stgit@djiang5-mobl3 Signed-off-by: Dan Williams --- drivers/cxl/acpi.c | 6 ++---- drivers/cxl/core/cdat.c | 17 ++++++++++------- drivers/cxl/core/pmem.c | 6 ++++-- drivers/cxl/core/port.c | 4 ++-- drivers/cxl/cxl.h | 14 +++++++------- drivers/cxl/port.c | 4 +++- 6 files changed, 28 insertions(+), 23 deletions(-) diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index afc712264d1c..dcf2b39e1048 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -295,14 +295,12 @@ cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, struct access_coordinate *coord, return rc; } -static int cxl_acpi_qos_class(struct cxl_port *root_port, +static int cxl_acpi_qos_class(struct cxl_root *cxl_root, struct access_coordinate *coord, int entries, int *qos_class) { + struct device *dev = cxl_root->port.uport_dev; acpi_handle handle; - struct device *dev; - - dev = root_port->uport_dev; if (!dev_is_platform(dev)) return -ENODEV; diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c index cd84d87f597a..0df5379cf02f 100644 --- a/drivers/cxl/core/cdat.c +++ b/drivers/cxl/core/cdat.c @@ -162,7 +162,6 @@ static int cxl_port_perf_data_calculate(struct cxl_port *port, struct xarray *dsmas_xa) { struct access_coordinate c; - struct cxl_port *root_port; struct cxl_root *cxl_root; struct dsmas_entry *dent; int valid_entries = 0; @@ -175,8 +174,7 @@ static int cxl_port_perf_data_calculate(struct cxl_port *port, return rc; } - root_port = find_cxl_root(port); - cxl_root = to_cxl_root(root_port); + cxl_root = find_cxl_root(port); if (!cxl_root->ops || !cxl_root->ops->qos_class) return -EOPNOTSUPP; @@ -193,7 +191,8 @@ static int cxl_port_perf_data_calculate(struct cxl_port *port, dent->coord.write_bandwidth); dent->entries = 1; - rc = cxl_root->ops->qos_class(root_port, &dent->coord, 1, &qos_class); + rc = cxl_root->ops->qos_class(cxl_root, &dent->coord, 1, + &qos_class); if (rc != 1) continue; @@ -349,15 +348,19 @@ 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; + struct cxl_port *root_port; int rc; - root_port = find_cxl_root(cxlmd->endpoint); - if (!root_port) + struct cxl_root *cxl_root __free(put_cxl_root) = + find_cxl_root(cxlmd->endpoint); + + if (!cxl_root) return -ENODEV; + root_port = &cxl_root->port; + /* 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); diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c index fc94f5240327..da92a901b9e8 100644 --- a/drivers/cxl/core/pmem.c +++ b/drivers/cxl/core/pmem.c @@ -64,12 +64,14 @@ static int match_nvdimm_bridge(struct device *dev, void *data) struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_memdev *cxlmd) { - struct cxl_port *port = find_cxl_root(cxlmd->endpoint); + struct cxl_root *cxl_root = find_cxl_root(cxlmd->endpoint); + struct cxl_port *port; struct device *dev; - if (!port) + if (!cxl_root) return NULL; + port = &cxl_root->port; dev = device_find_child(&port->dev, NULL, match_nvdimm_bridge); put_device(&port->dev); diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 64f30d5fe1f6..63a4e3c2baed 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -972,7 +972,7 @@ static bool dev_is_cxl_root_child(struct device *dev) return false; } -struct cxl_port *find_cxl_root(struct cxl_port *port) +struct cxl_root *find_cxl_root(struct cxl_port *port) { struct cxl_port *iter = port; @@ -982,7 +982,7 @@ struct cxl_port *find_cxl_root(struct cxl_port *port) if (!iter) return NULL; get_device(&iter->dev); - return iter; + return to_cxl_root(iter); } EXPORT_SYMBOL_NS_GPL(find_cxl_root, CXL); diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index df3db3e43913..3a5004aab97a 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -617,12 +617,6 @@ struct cxl_port { long pci_latency; }; -struct cxl_root_ops { - int (*qos_class)(struct cxl_port *root_port, - struct access_coordinate *coord, int entries, - int *qos_class); -}; - /** * struct cxl_root - logical collection of root cxl_port items * @@ -640,6 +634,12 @@ to_cxl_root(const struct cxl_port *port) return container_of(port, struct cxl_root, port); } +struct cxl_root_ops { + int (*qos_class)(struct cxl_root *cxl_root, + struct access_coordinate *coord, int entries, + int *qos_class); +}; + static inline struct cxl_dport * cxl_find_dport_by_dev(struct cxl_port *port, const struct device *dport_dev) { @@ -734,7 +734,7 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct cxl_dport *parent_dport); struct cxl_root *devm_cxl_add_root(struct device *host, const struct cxl_root_ops *ops); -struct cxl_port *find_cxl_root(struct cxl_port *port); +struct cxl_root *find_cxl_root(struct cxl_port *port); void put_cxl_root(struct cxl_root *cxl_root); DEFINE_FREE(put_cxl_root, struct cxl_root *, if (_T) put_cxl_root(_T)) diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c index da3c3a08bd62..4f3a08fdc9e9 100644 --- a/drivers/cxl/port.c +++ b/drivers/cxl/port.c @@ -94,6 +94,7 @@ static int cxl_endpoint_port_probe(struct cxl_port *port) struct cxl_endpoint_dvsec_info info = { .port = port }; struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev); struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct cxl_root *cxl_root; struct cxl_hdm *cxlhdm; struct cxl_port *root; int rc; @@ -130,7 +131,8 @@ static int cxl_endpoint_port_probe(struct cxl_port *port) * This can't fail in practice as CXL root exit unregisters all * descendant ports and that in turn synchronizes with cxl_port_probe() */ - root = find_cxl_root(port); + cxl_root = find_cxl_root(port); + root = &cxl_root->port; /* * Now that all endpoint decoders are successfully enumerated, try to From 98e7ab3345e105339b7d919b4918f3c1879052ed Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Fri, 5 Jan 2024 15:07:46 -0700 Subject: [PATCH 3/5] cxl: Fix device reference leak in cxl_port_perf_data_calculate() cxl_port_perf_data_calculate() calls find_cxl_root() and does not dereference the 'struct device' in the cxl_root->port. find_cxl_root() calls get_device() and takes a reference on the port 'struct device' member. Use the __free() macro to ensure the dereference happens. Fixes: 7a4f148dd8d5 ("cxl: Compute the entire CXL path latency and bandwidth data") Reviewed-by: Ira Weiny Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/170449246681.3779673.2288926019977963333.stgit@djiang5-mobl3 Signed-off-by: Dan Williams --- drivers/cxl/core/cdat.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c index 0df5379cf02f..c6208aab452f 100644 --- a/drivers/cxl/core/cdat.c +++ b/drivers/cxl/core/cdat.c @@ -162,7 +162,6 @@ static int cxl_port_perf_data_calculate(struct cxl_port *port, struct xarray *dsmas_xa) { struct access_coordinate c; - struct cxl_root *cxl_root; struct dsmas_entry *dent; int valid_entries = 0; unsigned long index; @@ -174,7 +173,11 @@ static int cxl_port_perf_data_calculate(struct cxl_port *port, return rc; } - cxl_root = find_cxl_root(port); + struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port); + + if (!cxl_root) + return -ENODEV; + if (!cxl_root->ops || !cxl_root->ops->qos_class) return -EOPNOTSUPP; From 66f11890d35a609012037cccfd9e63ed98474f99 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Fri, 5 Jan 2024 15:07:53 -0700 Subject: [PATCH 4/5] cxl: Refactor to use __free() for cxl_root allocation in cxl_find_nvdimm_bridge() Use scope-based resource management __free() macro to drop the open coded put_device() in cxl_find_nvdimm_bridge(). Reviewed-by: Ira Weiny Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/170449247353.3779673.5963704495491343135.stgit@djiang5-mobl3 Signed-off-by: Dan Williams --- drivers/cxl/core/pmem.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c index da92a901b9e8..e69625a8d6a1 100644 --- a/drivers/cxl/core/pmem.c +++ b/drivers/cxl/core/pmem.c @@ -64,16 +64,14 @@ static int match_nvdimm_bridge(struct device *dev, void *data) struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_memdev *cxlmd) { - struct cxl_root *cxl_root = find_cxl_root(cxlmd->endpoint); - struct cxl_port *port; + struct cxl_root *cxl_root __free(put_cxl_root) = + find_cxl_root(cxlmd->endpoint); struct device *dev; if (!cxl_root) return NULL; - port = &cxl_root->port; - dev = device_find_child(&port->dev, NULL, match_nvdimm_bridge); - put_device(&port->dev); + dev = device_find_child(&cxl_root->port.dev, NULL, match_nvdimm_bridge); if (!dev) return NULL; From 321dd36c286b3f982b341ce9a273b0f66f0e00ed Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Fri, 5 Jan 2024 15:07:59 -0700 Subject: [PATCH 5/5] cxl: Refactor to use __free() for cxl_root allocation in cxl_endpoint_port_probe() Use scope-based resource management __free() macro to drop the open coded put_device() in cxl_endpoint_port_probe(). Reviewed-by: Ira Weiny Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/170449247973.3779673.15088722836135359275.stgit@djiang5-mobl3 Signed-off-by: Dan Williams --- drivers/cxl/port.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c index 4f3a08fdc9e9..97c21566677a 100644 --- a/drivers/cxl/port.c +++ b/drivers/cxl/port.c @@ -94,7 +94,6 @@ static int cxl_endpoint_port_probe(struct cxl_port *port) struct cxl_endpoint_dvsec_info info = { .port = port }; struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev); struct cxl_dev_state *cxlds = cxlmd->cxlds; - struct cxl_root *cxl_root; struct cxl_hdm *cxlhdm; struct cxl_port *root; int rc; @@ -131,7 +130,8 @@ static int cxl_endpoint_port_probe(struct cxl_port *port) * This can't fail in practice as CXL root exit unregisters all * descendant ports and that in turn synchronizes with cxl_port_probe() */ - cxl_root = find_cxl_root(port); + struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port); + root = &cxl_root->port; /* @@ -139,7 +139,6 @@ static int cxl_endpoint_port_probe(struct cxl_port *port) * assemble regions from committed decoders */ device_for_each_child(&port->dev, root, discover_region); - put_device(&root->dev); return 0; }