| Message ID | 164298417755.3018233.850001481653928773.stgit@dwillia2-desk3.amr.corp.intel.com |
|---|---|
| State | New, archived |
| Headers | show |
| Series | CXL.mem Topology Discovery and Hotplug Support | expand |
On Sun, 23 Jan 2022 16:29:37 -0800 Dan Williams <dan.j.williams@intel.com> wrote: > From: Ben Widawsky <ben.widawsky@intel.com> > > Add wrappers for the creation of decoder objects at the root level and > switch level, and keep the core helper private to cxl/core/port.c. Root > decoders are static descriptors conveyed from platform firmware (e.g. > ACPI CFMWS). Switch decoders are CXL standard decoders enumerated via > the HDM decoder capability structure. The base address for the HDM > decoder capability structure may be conveyed either by PCIe or platform > firmware (ACPI CEDT.CHBS). The switch naming is a bit odd for host bridge decoders, but I can't immediately think of an alternative. Perhaps just call out that case in the relevant docs? Probably a good idea to call out that this patch also adds some documentation to related functions alongside the changes mentioned above. A few minor comments inline. Jonathan > > Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> > [djbw: fixup changelog] > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > drivers/cxl/acpi.c | 4 +- > drivers/cxl/core/port.c | 78 ++++++++++++++++++++++++++++++++++++++++++----- > drivers/cxl/cxl.h | 10 +++++- > 3 files changed, 81 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..2910c36a0e58 100644 > --- a/drivers/cxl/core/port.c > +++ b/drivers/cxl/core/port.c > @@ -495,13 +495,26 @@ static int decoder_populate_targets(struct cxl_decoder *cxld, > 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 +532,69 @@ 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 port of this decoder root port is a bit confusing here given the other meanings of that in PCI. Perhaps port of CXL root or something else? > + * @nr_targets: number of downstream targets. The number of downstream targets > + * is determined with a platform specific mechanism. > + * > + * Return: A new cxl decoder to be registered by cxl_decoder_add() > + */ > +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: number of downstream targets. The number of downstream targets > + * is determined via CXL capability registers. Perhaps call out that it's the _maximum_ number of downstream targets? Whether all are used is I think a configuration choice. The accessible wording you use above gives the appropriate indication of flexibility. > + * > + * Return: A new cxl decoder to be registered by cxl_decoder_add() > + */ > +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); > + > +/** This new documentation is non trivial enough it should either be in a separate patch, or at least called out in the patch description. > + * 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..e60878ab4569 100644 > --- a/drivers/cxl/cxl.h > +++ b/drivers/cxl/cxl.h > @@ -278,6 +278,11 @@ struct cxl_dport { > struct list_head list; > }; > > +static inline bool is_cxl_root(struct cxl_port *port) This is non obvious enough to perhaps warrant an explanation of why this condition indicates a cxl_root. > +{ > + 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 +293,10 @@ 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); > >
On Mon, Jan 31, 2022 at 6:47 AM Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: > > On Sun, 23 Jan 2022 16:29:37 -0800 > Dan Williams <dan.j.williams@intel.com> wrote: > > > From: Ben Widawsky <ben.widawsky@intel.com> > > > > Add wrappers for the creation of decoder objects at the root level and > > switch level, and keep the core helper private to cxl/core/port.c. Root > > decoders are static descriptors conveyed from platform firmware (e.g. > > ACPI CFMWS). Switch decoders are CXL standard decoders enumerated via > > the HDM decoder capability structure. The base address for the HDM > > decoder capability structure may be conveyed either by PCIe or platform > > firmware (ACPI CEDT.CHBS). > > The switch naming is a bit odd for host bridge decoders, but > I can't immediately think of an alternative. Perhaps just call > out that case in the relevant docs? You mean the kdoc for cxl_switch_decoder_alloc()? I'll add a comment along the lines of: "'Switch' decoders are any decoders 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." > > Probably a good idea to call out that this patch also adds some documentation > to related functions alongside the changes mentioned above. > > A few minor comments inline. > > Jonathan > > > > > Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> > > [djbw: fixup changelog] > > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > > --- > > drivers/cxl/acpi.c | 4 +- > > drivers/cxl/core/port.c | 78 ++++++++++++++++++++++++++++++++++++++++++----- > > drivers/cxl/cxl.h | 10 +++++- > > 3 files changed, 81 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..2910c36a0e58 100644 > > --- a/drivers/cxl/core/port.c > > +++ b/drivers/cxl/core/port.c > > @@ -495,13 +495,26 @@ static int decoder_populate_targets(struct cxl_decoder *cxld, > > 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 +532,69 @@ 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 port of this decoder > > root port is a bit confusing here given the other meanings of that in PCI. > Perhaps port of CXL root or something else? I'll add some verbiage defining CXL root independent of a PCIe Root Port. > > > + * @nr_targets: number of downstream targets. The number of downstream targets > > + * is determined with a platform specific mechanism. > > + * > > + * Return: A new cxl decoder to be registered by cxl_decoder_add() > > + */ > > +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: number of downstream targets. The number of downstream targets > > + * is determined via CXL capability registers. > > Perhaps call out that it's the _maximum_ number of downstream targets? > Whether all are used is I think a configuration choice. Correct, I can clean up kdoc a bit. > The accessible wording you use above gives the appropriate indication > of flexibility. > > > + * > > + * Return: A new cxl decoder to be registered by cxl_decoder_add() > > + */ > > +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); > > + > > +/** > > This new documentation is non trivial enough it should either be in a separate > patch, or at least called out in the patch description. Ok. > > > + * 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..e60878ab4569 100644 > > --- a/drivers/cxl/cxl.h > > +++ b/drivers/cxl/cxl.h > > @@ -278,6 +278,11 @@ struct cxl_dport { > > struct list_head list; > > }; > > > > +static inline bool is_cxl_root(struct cxl_port *port) > This is non obvious enough to perhaps warrant an explanation > of why this condition indicates a cxl_root. Sure. > > > +{ > > + 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 +293,10 @@ 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); > > > > >
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..2910c36a0e58 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -495,13 +495,26 @@ static int decoder_populate_targets(struct cxl_decoder *cxld, 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 +532,69 @@ 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 port of this decoder + * @nr_targets: number of downstream targets. The number of downstream targets + * is determined with a platform specific mechanism. + * + * Return: A new cxl decoder to be registered by cxl_decoder_add() + */ +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: number of downstream targets. The number of downstream targets + * is determined via CXL capability registers. + * + * Return: A new cxl decoder to be registered by cxl_decoder_add() + */ +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..e60878ab4569 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -278,6 +278,11 @@ struct cxl_dport { struct list_head list; }; +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 +293,10 @@ 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);