Re: [PATCH v9 06/16] cxl/pci: Move RAS initialization to cxl_port driver

["Bowman, Terry" <terry.bowman@amd.com>]

On 6/6/2025 12:04 PM, Dave Jiang wrote:
>
> On 6/3/25 10:22 AM, Terry Bowman wrote:
>> The cxl_port driver is intended to manage CXL Endpoint Ports and CXL Switch
>> Ports. Move existing RAS initialization to the cxl_port driver.
>>
>> Restricted CXL Host (RCH) Downstream Port RAS initialization currently
>> resides in cxl/core/pci.c. The PCI source file is not otherwise associated
>> with CXL Port management.
>>
>> Additional CXL Port RAS initialization will be added in future patches to
>> support a CXL Port device's CXL errors.
> Is this the part that Jonathan recommended moving to cxl/core/ras.c?
>
> DJ
Correct.

Terry
>> Signed-off-by: Terry Bowman <terry.bowman@amd.com>
>> ---
>>  drivers/cxl/core/pci.c  | 73 --------------------------------------
>>  drivers/cxl/core/regs.c |  2 ++
>>  drivers/cxl/cxl.h       |  6 ++++
>>  drivers/cxl/port.c      | 78 +++++++++++++++++++++++++++++++++++++++++
>>  4 files changed, 86 insertions(+), 73 deletions(-)
>>
>> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
>> index b50551601c2e..317cd0a91ffe 100644
>> --- a/drivers/cxl/core/pci.c
>> +++ b/drivers/cxl/core/pci.c
>> @@ -748,79 +748,6 @@ static bool cxl_handle_endpoint_ras(struct cxl_dev_state *cxlds)
>>  
>>  #ifdef CONFIG_PCIEAER_CXL
>>  
>> -static void cxl_dport_map_rch_aer(struct cxl_dport *dport)
>> -{
>> -	resource_size_t aer_phys;
>> -	struct device *host;
>> -	u16 aer_cap;
>> -
>> -	aer_cap = cxl_rcrb_to_aer(dport->dport_dev, dport->rcrb.base);
>> -	if (aer_cap) {
>> -		host = dport->reg_map.host;
>> -		aer_phys = aer_cap + dport->rcrb.base;
>> -		dport->regs.dport_aer = devm_cxl_iomap_block(host, aer_phys,
>> -						sizeof(struct aer_capability_regs));
>> -	}
>> -}
>> -
>> -static void cxl_dport_map_ras(struct cxl_dport *dport)
>> -{
>> -	struct cxl_register_map *map = &dport->reg_map;
>> -	struct device *dev = dport->dport_dev;
>> -
>> -	if (!map->component_map.ras.valid)
>> -		dev_dbg(dev, "RAS registers not found\n");
>> -	else if (cxl_map_component_regs(map, &dport->regs.component,
>> -					BIT(CXL_CM_CAP_CAP_ID_RAS)))
>> -		dev_dbg(dev, "Failed to map RAS capability.\n");
>> -}
>> -
>> -static void cxl_disable_rch_root_ints(struct cxl_dport *dport)
>> -{
>> -	void __iomem *aer_base = dport->regs.dport_aer;
>> -	u32 aer_cmd_mask, aer_cmd;
>> -
>> -	if (!aer_base)
>> -		return;
>> -
>> -	/*
>> -	 * Disable RCH root port command interrupts.
>> -	 * CXL 3.0 12.2.1.1 - RCH Downstream Port-detected Errors
>> -	 *
>> -	 * This sequence may not be necessary. CXL spec states disabling
>> -	 * the root cmd register's interrupts is required. But, PCI spec
>> -	 * shows these are disabled by default on reset.
>> -	 */
>> -	aer_cmd_mask = (PCI_ERR_ROOT_CMD_COR_EN |
>> -			PCI_ERR_ROOT_CMD_NONFATAL_EN |
>> -			PCI_ERR_ROOT_CMD_FATAL_EN);
>> -	aer_cmd = readl(aer_base + PCI_ERR_ROOT_COMMAND);
>> -	aer_cmd &= ~aer_cmd_mask;
>> -	writel(aer_cmd, aer_base + PCI_ERR_ROOT_COMMAND);
>> -}
>> -
>> -/**
>> - * cxl_dport_init_ras_reporting - Setup CXL RAS report on this dport
>> - * @dport: the cxl_dport that needs to be initialized
>> - * @host: host device for devm operations
>> - */
>> -void cxl_dport_init_ras_reporting(struct cxl_dport *dport, struct device *host)
>> -{
>> -	dport->reg_map.host = host;
>> -	cxl_dport_map_ras(dport);
>> -
>> -	if (dport->rch) {
>> -		struct pci_host_bridge *host_bridge = to_pci_host_bridge(dport->dport_dev);
>> -
>> -		if (!host_bridge->native_aer)
>> -			return;
>> -
>> -		cxl_dport_map_rch_aer(dport);
>> -		cxl_disable_rch_root_ints(dport);
>> -	}
>> -}
>> -EXPORT_SYMBOL_NS_GPL(cxl_dport_init_ras_reporting, "CXL");
>> -
>>  static void cxl_handle_rdport_cor_ras(struct cxl_dev_state *cxlds,
>>  					  struct cxl_dport *dport)
>>  {
>> diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
>> index 5ca7b0eed568..b8e767a9571c 100644
>> --- a/drivers/cxl/core/regs.c
>> +++ b/drivers/cxl/core/regs.c
>> @@ -199,6 +199,7 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr,
>>  
>>  	return ret_val;
>>  }
>> +EXPORT_SYMBOL_NS_GPL(devm_cxl_iomap_block, "CXL");
>>  
>>  int cxl_map_component_regs(const struct cxl_register_map *map,
>>  			   struct cxl_component_regs *regs,
>> @@ -517,6 +518,7 @@ u16 cxl_rcrb_to_aer(struct device *dev, resource_size_t rcrb)
>>  
>>  	return offset;
>>  }
>> +EXPORT_SYMBOL_NS_GPL(cxl_rcrb_to_aer, "CXL");
>>  
>>  static resource_size_t cxl_rcrb_to_linkcap(struct device *dev, struct cxl_dport *dport)
>>  {
>> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
>> index ba08b77b65da..0dc43bfba76a 100644
>> --- a/drivers/cxl/cxl.h
>> +++ b/drivers/cxl/cxl.h
>> @@ -313,6 +313,12 @@ int cxl_setup_regs(struct cxl_register_map *map);
>>  struct cxl_dport;
>>  resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
>>  					   struct cxl_dport *dport);
>> +
>> +u16 cxl_rcrb_to_aer(struct device *dev, resource_size_t rcrb);
>> +
>> +void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr,
>> +				   resource_size_t length);
>> +
>>  int cxl_dport_map_rcd_linkcap(struct pci_dev *pdev, struct cxl_dport *dport);
>>  
>>  #define CXL_RESOURCE_NONE ((resource_size_t) -1)
>> diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
>> index fe4b593331da..7b61f09347a5 100644
>> --- a/drivers/cxl/port.c
>> +++ b/drivers/cxl/port.c
>> @@ -6,6 +6,7 @@
>>  
>>  #include "cxlmem.h"
>>  #include "cxlpci.h"
>> +#include "cxl.h"
>>  
>>  /**
>>   * DOC: cxl port
>> @@ -57,6 +58,83 @@ static int discover_region(struct device *dev, void *unused)
>>  	return 0;
>>  }
>>  
>> +#ifdef CONFIG_PCIEAER_CXL
>> +
>> +static void cxl_dport_map_rch_aer(struct cxl_dport *dport)
>> +{
>> +	resource_size_t aer_phys;
>> +	struct device *host;
>> +	u16 aer_cap;
>> +
>> +	aer_cap = cxl_rcrb_to_aer(dport->dport_dev, dport->rcrb.base);
>> +	if (aer_cap) {
>> +		host = dport->reg_map.host;
>> +		aer_phys = aer_cap + dport->rcrb.base;
>> +		dport->regs.dport_aer = devm_cxl_iomap_block(host, aer_phys,
>> +						sizeof(struct aer_capability_regs));
>> +	}
>> +}
>> +
>> +static void cxl_dport_map_ras(struct cxl_dport *dport)
>> +{
>> +	struct cxl_register_map *map = &dport->reg_map;
>> +	struct device *dev = dport->dport_dev;
>> +
>> +	if (!map->component_map.ras.valid)
>> +		dev_dbg(dev, "RAS registers not found\n");
>> +	else if (cxl_map_component_regs(map, &dport->regs.component,
>> +					BIT(CXL_CM_CAP_CAP_ID_RAS)))
>> +		dev_dbg(dev, "Failed to map RAS capability.\n");
>> +}
>> +
>> +static void cxl_disable_rch_root_ints(struct cxl_dport *dport)
>> +{
>> +	void __iomem *aer_base = dport->regs.dport_aer;
>> +	u32 aer_cmd_mask, aer_cmd;
>> +
>> +	if (!aer_base)
>> +		return;
>> +
>> +	/*
>> +	 * Disable RCH root port command interrupts.
>> +	 * CXL 3.0 12.2.1.1 - RCH Downstream Port-detected Errors
>> +	 *
>> +	 * This sequence may not be necessary. CXL spec states disabling
>> +	 * the root cmd register's interrupts is required. But, PCI spec
>> +	 * shows these are disabled by default on reset.
>> +	 */
>> +	aer_cmd_mask = (PCI_ERR_ROOT_CMD_COR_EN |
>> +			PCI_ERR_ROOT_CMD_NONFATAL_EN |
>> +			PCI_ERR_ROOT_CMD_FATAL_EN);
>> +	aer_cmd = readl(aer_base + PCI_ERR_ROOT_COMMAND);
>> +	aer_cmd &= ~aer_cmd_mask;
>> +	writel(aer_cmd, aer_base + PCI_ERR_ROOT_COMMAND);
>> +}
>> +
>> +/**
>> + * cxl_dport_init_ras_reporting - Setup CXL RAS report on this dport
>> + * @dport: the cxl_dport that needs to be initialized
>> + * @host: host device for devm operations
>> + */
>> +void cxl_dport_init_ras_reporting(struct cxl_dport *dport, struct device *host)
>> +{
>> +	dport->reg_map.host = host;
>> +	cxl_dport_map_ras(dport);
>> +
>> +	if (dport->rch) {
>> +		struct pci_host_bridge *host_bridge = to_pci_host_bridge(dport->dport_dev);
>> +
>> +		if (!host_bridge->native_aer)
>> +			return;
>> +
>> +		cxl_dport_map_rch_aer(dport);
>> +		cxl_disable_rch_root_ints(dport);
>> +	}
>> +}
>> +EXPORT_SYMBOL_NS_GPL(cxl_dport_init_ras_reporting, "CXL");
>> +
>> +#endif /* CONFIG_PCIEAER_CXL */
>> +
>>  static int cxl_switch_port_probe(struct cxl_port *port)
>>  {
>>  	struct cxl_hdm *cxlhdm;