Re: [PATCH v3 25/40] cxl/core/port: Remove @host argument for dport + decoder enumeration

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Sun, 23 Jan 2022 16:30:52 -0800
Dan Williams <dan.j.williams@intel.com> wrote:

> Now that dport and decoder enumeration is centralized in the port
> driver, the @host argument for these helpers can be made implicit. For
> the root port the host is the port's uport device (ACPI0017 for
> cxl_acpi), and for all other descendant ports the devm context is the
> parent of @port.
> 
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Some minor docs follow through from earlier patches.

Jonathan

> ---
>  drivers/cxl/acpi.c            |    2 +-
>  drivers/cxl/core/hdm.c        |   10 +++++-----
>  drivers/cxl/core/pci.c        |    8 ++------
>  drivers/cxl/core/port.c       |    9 +++++++--
>  drivers/cxl/cxl.h             |    8 ++++----
>  drivers/cxl/cxlpci.h          |    2 +-
>  drivers/cxl/port.c            |    8 ++++----
>  tools/testing/cxl/test/cxl.c  |   14 +++++---------
>  tools/testing/cxl/test/mock.c |   28 ++++++++++++----------------
>  tools/testing/cxl/test/mock.h |    9 ++++-----
>  10 files changed, 45 insertions(+), 53 deletions(-)
> 
> diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
> index 82591642ea90..683f2ca32c97 100644
> --- a/drivers/cxl/acpi.c
> +++ b/drivers/cxl/acpi.c
> @@ -256,7 +256,7 @@ static int add_host_bridge_dport(struct device *match, void *arg)
>  		return 0;
>  	}
>  
> -	dport = devm_cxl_add_dport(host, root_port, match, uid, ctx.chbcr);
> +	dport = devm_cxl_add_dport(root_port, match, uid, ctx.chbcr);
>  	if (IS_ERR(dport)) {
>  		dev_err(host, "failed to add downstream port: %s\n",
>  			dev_name(match));
> diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
> index 802048dc2046..701b510c76d2 100644
> --- a/drivers/cxl/core/hdm.c
> +++ b/drivers/cxl/core/hdm.c
> @@ -44,7 +44,7 @@ static int add_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
>   * are claimed and passed to the single dport. Disable the range until the first
>   * CXL region is enumerated / activated.
>   */
> -int devm_cxl_add_passthrough_decoder(struct device *host, struct cxl_port *port)
> +int devm_cxl_add_passthrough_decoder(struct cxl_port *port)
>  {
>  	struct cxl_decoder *cxld;
>  	struct cxl_dport *dport;
> @@ -96,18 +96,18 @@ static void __iomem *map_hdm_decoder_regs(struct cxl_port *port,
>   * devm_cxl_setup_hdm - map HDM decoder component registers
>   * @port: cxl_port to map
>   */
> -struct cxl_hdm *devm_cxl_setup_hdm(struct device *host, struct cxl_port *port)
> +struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port)

If it had been here earlier you'd now need to drop the docs for host.

>  {
>  	void __iomem *crb, __iomem *hdm;
>  	struct device *dev = &port->dev;
>  	struct cxl_hdm *cxlhdm;
>  
> -	cxlhdm = devm_kzalloc(host, sizeof(*cxlhdm), GFP_KERNEL);
> +	cxlhdm = devm_kzalloc(dev, sizeof(*cxlhdm), GFP_KERNEL);
>  	if (!cxlhdm)
>  		return ERR_PTR(-ENOMEM);
>  
>  	cxlhdm->port = port;
> -	crb = devm_cxl_iomap_block(host, port->component_reg_phys,
> +	crb = devm_cxl_iomap_block(dev, port->component_reg_phys,
>  				   CXL_COMPONENT_REG_BLOCK_SIZE);
>  	if (!crb) {
>  		dev_err(dev, "No component registers mapped\n");
> @@ -197,7 +197,7 @@ static void init_hdm_decoder(struct cxl_decoder *cxld, int *target_map,
>   * devm_cxl_enumerate_decoders - add decoder objects per HDM register set
>   * @port: cxl_port HDM capability to scan

Well that's not right.  

>   */
> -int devm_cxl_enumerate_decoders(struct device *host, struct cxl_hdm *cxlhdm)
> +int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
>  {
>  	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
>  	struct cxl_port *port = cxlhdm->port;
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index a04220ebc03f..420296abc57a 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -15,7 +15,6 @@
>  
>  struct cxl_walk_context {
>  	struct pci_bus *bus;
> -	struct device *host;
>  	struct cxl_port *port;
>  	int type;
>  	int error;
> @@ -26,7 +25,6 @@ static int match_add_dports(struct pci_dev *pdev, void *data)
>  {
>  	struct cxl_walk_context *ctx = data;
>  	struct cxl_port *port = ctx->port;
> -	struct device *host = ctx->host;
>  	struct pci_bus *bus = ctx->bus;
>  	int type = pci_pcie_type(pdev);
>  	struct cxl_register_map map;
> @@ -50,7 +48,7 @@ static int match_add_dports(struct pci_dev *pdev, void *data)
>  		dev_dbg(&port->dev, "failed to find component registers\n");
>  
>  	port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap);
> -	dport = devm_cxl_add_dport(host, port, &pdev->dev, port_num,
> +	dport = devm_cxl_add_dport(port, &pdev->dev, port_num,
>  				   cxl_regmap_to_base(pdev, &map));
>  	if (IS_ERR(dport)) {
>  		ctx->error = PTR_ERR(dport);
> @@ -65,13 +63,12 @@ static int match_add_dports(struct pci_dev *pdev, void *data)
>  
>  /**
>   * devm_cxl_port_enumerate_dports - enumerate downstream ports of the upstream port
> - * @host: devm context
>   * @port: cxl_port whose ->uport is the upstream of dports to be enumerated
>   *
>   * Returns a positive number of dports enumerated or a negative error
>   * code.
>   */
> -int devm_cxl_port_enumerate_dports(struct device *host, struct cxl_port *port)
> +int devm_cxl_port_enumerate_dports(struct cxl_port *port)
>  {
>  	struct pci_bus *bus = cxl_port_to_pci_bus(port);
>  	struct cxl_walk_context ctx;
> @@ -86,7 +83,6 @@ int devm_cxl_port_enumerate_dports(struct device *host, struct cxl_port *port)
>  		type = PCI_EXP_TYPE_DOWNSTREAM;
>  
>  	ctx = (struct cxl_walk_context) {
> -		.host = host,
>  		.port = port,
>  		.bus = bus,
>  		.type = type,
> diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
> index efe66a8633a8..26c3eb9180cd 100644
> --- a/drivers/cxl/core/port.c
> +++ b/drivers/cxl/core/port.c
> @@ -573,7 +573,6 @@ static void cxl_dport_unlink(void *data)
>  
>  /**
>   * devm_cxl_add_dport - append downstream port data to a cxl_port
> - * @host: devm context for allocations
>   * @port: the cxl_port that references this dport
>   * @dport_dev: firmware or PCI device representing the dport
>   * @port_id: identifier for this dport in a decoder's target list
> @@ -583,14 +582,20 @@ static void cxl_dport_unlink(void *data)
>   * either the port's host (for root ports), or the port itself (for
>   * switch ports)
>   */
> -struct cxl_dport *devm_cxl_add_dport(struct device *host, struct cxl_port *port,
> +struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port,
>  				     struct device *dport_dev, int port_id,
>  				     resource_size_t component_reg_phys)
>  {
>  	char link_name[CXL_TARGET_STRLEN];
>  	struct cxl_dport *dport;
> +	struct device *host;
>  	int rc;
>  
> +	if (is_cxl_root(port))
> +		host = port->uport;
> +	else
> +		host = &port->dev;
> +
>  	if (!host->driver) {
>  		dev_WARN_ONCE(&port->dev, 1, "dport:%s bad devm context\n",
>  			      dev_name(dport_dev));
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index cee71c6e2fed..7c714e559e95 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -307,7 +307,7 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport,
>  				   resource_size_t component_reg_phys,
>  				   struct cxl_port *parent_port);
>  struct cxl_port *find_cxl_root(struct device *dev);
> -struct cxl_dport *devm_cxl_add_dport(struct device *host, struct cxl_port *port,
> +struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port,
>  				     struct device *dport, int port_id,
>  				     resource_size_t component_reg_phys);
>  struct cxl_decoder *to_cxl_decoder(struct device *dev);
> @@ -321,9 +321,9 @@ int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map);
>  int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map);
>  int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld);
>  struct cxl_hdm;
> -struct cxl_hdm *devm_cxl_setup_hdm(struct device *host, struct cxl_port *port);
> -int devm_cxl_enumerate_decoders(struct device *host, struct cxl_hdm *cxlhdm);
> -int devm_cxl_add_passthrough_decoder(struct device *host, struct cxl_port *port);
> +struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port);
> +int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm);
> +int devm_cxl_add_passthrough_decoder(struct cxl_port *port);
>  
>  extern struct bus_type cxl_bus_type;
>  
> diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
> index 47640f19e899..766de340c4ce 100644
> --- a/drivers/cxl/cxlpci.h
> +++ b/drivers/cxl/cxlpci.h
> @@ -58,5 +58,5 @@ static inline resource_size_t cxl_regmap_to_base(struct pci_dev *pdev,
>  	return pci_resource_start(pdev, map->barno) + map->block_offset;
>  }
>  
> -int devm_cxl_port_enumerate_dports(struct device *host, struct cxl_port *port);
> +int devm_cxl_port_enumerate_dports(struct cxl_port *port);
>  #endif /* __CXL_PCI_H__ */
> diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
> index 7b42f27c0c96..ae94a537eccc 100644
> --- a/drivers/cxl/port.c
> +++ b/drivers/cxl/port.c
> @@ -31,18 +31,18 @@ static int cxl_port_probe(struct device *dev)
>  	struct cxl_hdm *cxlhdm;
>  	int rc;
>  
> -	rc = devm_cxl_port_enumerate_dports(dev, port);
> +	rc = devm_cxl_port_enumerate_dports(port);
>  	if (rc < 0)
>  		return rc;
>  
>  	if (rc == 1)
> -		return devm_cxl_add_passthrough_decoder(dev, port);
> +		return devm_cxl_add_passthrough_decoder(port);
>  
> -	cxlhdm = devm_cxl_setup_hdm(dev, port);
> +	cxlhdm = devm_cxl_setup_hdm(port);
>  	if (IS_ERR(cxlhdm))
>  		return PTR_ERR(cxlhdm);
>  
> -	rc = devm_cxl_enumerate_decoders(dev, cxlhdm);
> +	rc = devm_cxl_enumerate_decoders(cxlhdm);
>  	if (rc) {
>  		dev_err(&port->dev, "Couldn't enumerate decoders (%d)\n", rc);
>  		return rc;
> diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
> index ce6ace286fc7..40ed567952e6 100644
> --- a/tools/testing/cxl/test/cxl.c
> +++ b/tools/testing/cxl/test/cxl.c
> @@ -399,8 +399,7 @@ static struct acpi_pci_root *mock_acpi_pci_find_root(acpi_handle handle)
>  	return &mock_pci_root[host_bridge_index(adev)];
>  }
>  
> -static struct cxl_hdm *mock_cxl_setup_hdm(struct device *host,
> -					  struct cxl_port *port)
> +static struct cxl_hdm *mock_cxl_setup_hdm(struct cxl_port *port)
>  {
>  	struct cxl_hdm *cxlhdm = devm_kzalloc(&port->dev, sizeof(*cxlhdm), GFP_KERNEL);
>  
> @@ -411,21 +410,18 @@ static struct cxl_hdm *mock_cxl_setup_hdm(struct device *host,
>  	return cxlhdm;
>  }
>  
> -static int mock_cxl_add_passthrough_decoder(struct device *host,
> -					    struct cxl_port *port)
> +static int mock_cxl_add_passthrough_decoder(struct cxl_port *port)
>  {
>  	dev_err(&port->dev, "unexpected passthrough decoder for cxl_test\n");
>  	return -EOPNOTSUPP;
>  }
>  
> -static int mock_cxl_enumerate_decoders(struct device *host,
> -				       struct cxl_hdm *cxlhdm)
> +static int mock_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
>  {
>  	return 0;
>  }
>  
> -static int mock_cxl_port_enumerate_dports(struct device *host,
> -					  struct cxl_port *port)
> +static int mock_cxl_port_enumerate_dports(struct cxl_port *port)
>  {
>  	struct device *dev = &port->dev;
>  	int i;
> @@ -437,7 +433,7 @@ static int mock_cxl_port_enumerate_dports(struct device *host,
>  		if (pdev->dev.parent != port->uport)
>  			continue;
>  
> -		dport = devm_cxl_add_dport(host, port, &pdev->dev, pdev->id,
> +		dport = devm_cxl_add_dport(port, &pdev->dev, pdev->id,
>  					   CXL_RESOURCE_NONE);
>  
>  		if (IS_ERR(dport)) {
> diff --git a/tools/testing/cxl/test/mock.c b/tools/testing/cxl/test/mock.c
> index 18d3b65e2a9b..6e8c9d63c92d 100644
> --- a/tools/testing/cxl/test/mock.c
> +++ b/tools/testing/cxl/test/mock.c
> @@ -131,66 +131,62 @@ __wrap_nvdimm_bus_register(struct device *dev,
>  }
>  EXPORT_SYMBOL_GPL(__wrap_nvdimm_bus_register);
>  
> -struct cxl_hdm *__wrap_devm_cxl_setup_hdm(struct device *host,
> -					  struct cxl_port *port)
> +struct cxl_hdm *__wrap_devm_cxl_setup_hdm(struct cxl_port *port)
>  {
>  	int index;
>  	struct cxl_hdm *cxlhdm;
>  	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
>  
>  	if (ops && ops->is_mock_port(port->uport))
> -		cxlhdm = ops->devm_cxl_setup_hdm(host, port);
> +		cxlhdm = ops->devm_cxl_setup_hdm(port);
>  	else
> -		cxlhdm = devm_cxl_setup_hdm(host, port);
> +		cxlhdm = devm_cxl_setup_hdm(port);
>  	put_cxl_mock_ops(index);
>  
>  	return cxlhdm;
>  }
>  EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_setup_hdm, CXL);
>  
> -int __wrap_devm_cxl_add_passthrough_decoder(struct device *host,
> -					    struct cxl_port *port)
> +int __wrap_devm_cxl_add_passthrough_decoder(struct cxl_port *port)
>  {
>  	int rc, index;
>  	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
>  
>  	if (ops && ops->is_mock_port(port->uport))
> -		rc = ops->devm_cxl_add_passthrough_decoder(host, port);
> +		rc = ops->devm_cxl_add_passthrough_decoder(port);
>  	else
> -		rc = devm_cxl_add_passthrough_decoder(host, port);
> +		rc = devm_cxl_add_passthrough_decoder(port);
>  	put_cxl_mock_ops(index);
>  
>  	return rc;
>  }
>  EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_add_passthrough_decoder, CXL);
>  
> -int __wrap_devm_cxl_enumerate_decoders(struct device *host,
> -				       struct cxl_hdm *cxlhdm)
> +int __wrap_devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
>  {
>  	int rc, index;
>  	struct cxl_port *port = cxlhdm->port;
>  	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
>  
>  	if (ops && ops->is_mock_port(port->uport))
> -		rc = ops->devm_cxl_enumerate_decoders(host, cxlhdm);
> +		rc = ops->devm_cxl_enumerate_decoders(cxlhdm);
>  	else
> -		rc = devm_cxl_enumerate_decoders(host, cxlhdm);
> +		rc = devm_cxl_enumerate_decoders(cxlhdm);
>  	put_cxl_mock_ops(index);
>  
>  	return rc;
>  }
>  EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_enumerate_decoders, CXL);
>  
> -int __wrap_devm_cxl_port_enumerate_dports(struct device *host,
> -					  struct cxl_port *port)
> +int __wrap_devm_cxl_port_enumerate_dports(struct cxl_port *port)
>  {
>  	int rc, index;
>  	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
>  
>  	if (ops && ops->is_mock_port(port->uport))
> -		rc = ops->devm_cxl_port_enumerate_dports(host, port);
> +		rc = ops->devm_cxl_port_enumerate_dports(port);
>  	else
> -		rc = devm_cxl_port_enumerate_dports(host, port);
> +		rc = devm_cxl_port_enumerate_dports(port);
>  	put_cxl_mock_ops(index);
>  
>  	return rc;
> diff --git a/tools/testing/cxl/test/mock.h b/tools/testing/cxl/test/mock.h
> index 15e48063ea4b..738f24e3988a 100644
> --- a/tools/testing/cxl/test/mock.h
> +++ b/tools/testing/cxl/test/mock.h
> @@ -19,11 +19,10 @@ struct cxl_mock_ops {
>  	bool (*is_mock_bus)(struct pci_bus *bus);
>  	bool (*is_mock_port)(struct device *dev);
>  	bool (*is_mock_dev)(struct device *dev);
> -	int (*devm_cxl_port_enumerate_dports)(struct device *host,
> -					      struct cxl_port *port);
> -	struct cxl_hdm *(*devm_cxl_setup_hdm)(struct device *host, struct cxl_port *port);
> -	int (*devm_cxl_add_passthrough_decoder)(struct device *host, struct cxl_port *port);
> -	int (*devm_cxl_enumerate_decoders)(struct device *host, struct cxl_hdm *hdm);
> +	int (*devm_cxl_port_enumerate_dports)(struct cxl_port *port);
> +	struct cxl_hdm *(*devm_cxl_setup_hdm)(struct cxl_port *port);
> +	int (*devm_cxl_add_passthrough_decoder)(struct cxl_port *port);
> +	int (*devm_cxl_enumerate_decoders)(struct cxl_hdm *hdm);
>  };
>  
>  void register_cxl_mock_ops(struct cxl_mock_ops *ops);
>