diff options
| -rw-r--r-- | drivers/cxl/acpi.c | 4 | ||||
| -rw-r--r-- | drivers/cxl/core/port.c | 83 | ||||
| -rw-r--r-- | drivers/cxl/cxl.h | 16 |
3 files changed, 92 insertions, 11 deletions
diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index da70f1836db6..0b267eabb15e 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -102,7 +102,7 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, for (i = 0; i < CFMWS_INTERLEAVE_WAYS(cfmws); i++) target_map[i] = cfmws->interleave_targets[i]; - cxld = cxl_decoder_alloc(root_port, CFMWS_INTERLEAVE_WAYS(cfmws)); + cxld = cxl_root_decoder_alloc(root_port, CFMWS_INTERLEAVE_WAYS(cfmws)); if (IS_ERR(cxld)) return 0; @@ -260,7 +260,7 @@ static int add_host_bridge_uport(struct device *match, void *arg) * dport. Disable the range until the first CXL region is enumerated / * activated. */ - cxld = cxl_decoder_alloc(port, 1); + cxld = cxl_switch_decoder_alloc(port, 1); if (IS_ERR(cxld)) return PTR_ERR(cxld); diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 63c76cb2a2ec..88ffec71464a 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -495,13 +495,26 @@ out_unlock: return rc; } -struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, int nr_targets) +/** + * cxl_decoder_alloc - Allocate a new CXL decoder + * @port: owning port of this decoder + * @nr_targets: downstream targets accessible by this decoder. All upstream + * ports and root ports must have at least 1 target. + * + * A port should contain one or more decoders. Each of those decoders enable + * some address space for CXL.mem utilization. A decoder is expected to be + * configured by the caller before registering. + * + * Return: A new cxl decoder to be registered by cxl_decoder_add() + */ +static struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, + unsigned int nr_targets) { struct cxl_decoder *cxld; struct device *dev; int rc = 0; - if (nr_targets > CXL_DECODER_MAX_INTERLEAVE || nr_targets < 1) + if (nr_targets > CXL_DECODER_MAX_INTERLEAVE || nr_targets == 0) return ERR_PTR(-EINVAL); cxld = kzalloc(struct_size(cxld, target, nr_targets), GFP_KERNEL); @@ -519,20 +532,74 @@ struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, int nr_targets) device_set_pm_not_required(dev); dev->parent = &port->dev; dev->bus = &cxl_bus_type; - - /* root ports do not have a cxl_port_type parent */ - if (port->dev.parent->type == &cxl_port_type) - dev->type = &cxl_decoder_switch_type; + if (is_cxl_root(port)) + cxld->dev.type = &cxl_decoder_root_type; else - dev->type = &cxl_decoder_root_type; + cxld->dev.type = &cxl_decoder_switch_type; return cxld; err: kfree(cxld); return ERR_PTR(rc); } -EXPORT_SYMBOL_NS_GPL(cxl_decoder_alloc, CXL); +/** + * cxl_root_decoder_alloc - Allocate a root level decoder + * @port: owning CXL root of this decoder + * @nr_targets: static number of downstream targets + * + * Return: A new cxl decoder to be registered by cxl_decoder_add(). A + * 'CXL root' decoder is one that decodes from a top-level / static platform + * firmware description of CXL resources into a CXL standard decode + * topology. + */ +struct cxl_decoder *cxl_root_decoder_alloc(struct cxl_port *port, + unsigned int nr_targets) +{ + if (!is_cxl_root(port)) + return ERR_PTR(-EINVAL); + + return cxl_decoder_alloc(port, nr_targets); +} +EXPORT_SYMBOL_NS_GPL(cxl_root_decoder_alloc, CXL); + +/** + * cxl_switch_decoder_alloc - Allocate a switch level decoder + * @port: owning CXL switch port of this decoder + * @nr_targets: max number of dynamically addressable downstream targets + * + * Return: A new cxl decoder to be registered by cxl_decoder_add(). A + * 'switch' decoder is any decoder that can be enumerated by PCIe + * topology and the HDM Decoder Capability. This includes the decoders + * that sit between Switch Upstream Ports / Switch Downstream Ports and + * Host Bridges / Root Ports. + */ +struct cxl_decoder *cxl_switch_decoder_alloc(struct cxl_port *port, + unsigned int nr_targets) +{ + if (is_cxl_root(port)) + return ERR_PTR(-EINVAL); + + return cxl_decoder_alloc(port, nr_targets); +} +EXPORT_SYMBOL_NS_GPL(cxl_switch_decoder_alloc, CXL); + +/** + * cxl_decoder_add - Add a decoder with targets + * @cxld: The cxl decoder allocated by cxl_decoder_alloc() + * @target_map: A list of downstream ports that this decoder can direct memory + * traffic to. These numbers should correspond with the port number + * in the PCIe Link Capabilities structure. + * + * Certain types of decoders may not have any targets. The main example of this + * is an endpoint device. A more awkward example is a hostbridge whose root + * ports get hot added (technically possible, though unlikely). + * + * Context: Process context. Takes and releases the cxld's device lock. + * + * Return: Negative error code if the decoder wasn't properly configured; else + * returns 0. + */ int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map) { struct cxl_port *port; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index bfd95acea66c..621a70e023c1 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -278,6 +278,17 @@ struct cxl_dport { struct list_head list; }; +/* + * The platform firmware device hosting the root is also the top of the + * CXL port topology. All other CXL ports have another CXL port as their + * parent and their ->uport / host device is out-of-line of the port + * ancestry. + */ +static inline bool is_cxl_root(struct cxl_port *port) +{ + return port->uport == port->dev.parent; +} + struct cxl_port *to_cxl_port(struct device *dev); struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport, resource_size_t component_reg_phys, @@ -288,7 +299,10 @@ int cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id, struct cxl_decoder *to_cxl_decoder(struct device *dev); bool is_root_decoder(struct device *dev); -struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, int nr_targets); +struct cxl_decoder *cxl_root_decoder_alloc(struct cxl_port *port, + unsigned int nr_targets); +struct cxl_decoder *cxl_switch_decoder_alloc(struct cxl_port *port, + unsigned int nr_targets); int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map); int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld); |