Re: [PATCH v3 02/20] cxl: add capabilities field to cxl_dev_state and cxl_port

Dave Jiang
2024-09-11T22:17:09Z

On 9/7/24 1:18 AM, alejandro.lucero-palau@amd.com wrote:
> From: Alejandro Lucero <alucerop@amd.com>
>
> Type2 devices have some Type3 functionalities as optional like an mbox
> or an hdm decoder, and CXL core needs a way to know what an CXL accelerator
> implements.
>
> Add a new field for keeping device capabilities as discovered during
> initialization.
>
> Add same field to cxl_port which for an endpoint will use those
> capabilities discovered previously, and which will be initialized when
> calling cxl_port_setup_regs for no endpoints.

I don't quite understand what you are trying to say here.

>
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> ---
> drivers/cxl/core/port.c | 9 +++++----
> drivers/cxl/core/regs.c | 20 +++++++++++++-------
> drivers/cxl/cxl.h | 8 +++++---
> drivers/cxl/cxlmem.h | 2 ++
> drivers/cxl/pci.c | 9 +++++----
> include/linux/cxl/cxl.h | 30 ++++++++++++++++++++++++++++++
> 6 files changed, 60 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
> index 1d5007e3795a..39b20ddd0296 100644
> --- a/drivers/cxl/core/port.c
> +++ b/drivers/cxl/core/port.c
> @@ -749,7 +749,7 @@ static struct cxl_port *cxl_port_alloc(struct device *uport_dev,
> }
>
> static int cxl_setup_comp_regs(struct device *host, struct cxl_register_map *map,
> - resource_size_t component_reg_phys)
> + resource_size_t component_reg_phys, u32 *caps)
> {
> *map = (struct cxl_register_map) {
> .host = host,
> @@ -763,7 +763,7 @@ static int cxl_setup_comp_regs(struct device *host, struct cxl_register_map *map
> map->reg_type = CXL_REGLOC_RBI_COMPONENT;
> map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE;
>
> - return cxl_setup_regs(map);
> + return cxl_setup_regs(map, caps);
> }
>
> static int cxl_port_setup_regs(struct cxl_port *port,
> @@ -772,7 +772,7 @@ static int cxl_port_setup_regs(struct cxl_port *port,
> if (dev_is_platform(port->uport_dev))
> return 0;
> return cxl_setup_comp_regs(&port->dev, &port->reg_map,
> - component_reg_phys);
> + component_reg_phys, &port->capabilities);
> }
>
> static int cxl_dport_setup_regs(struct device *host, struct cxl_dport *dport,
> @@ -789,7 +789,7 @@ static int cxl_dport_setup_regs(struct device *host, struct cxl_dport *dport,
> * NULL.
> */
> rc = cxl_setup_comp_regs(dport->dport_dev, &dport->reg_map,
> - component_reg_phys);
> + component_reg_phys, &dport->port->capabilities);
> dport->reg_map.host = host;
> return rc;
> }
> @@ -858,6 +858,7 @@ static struct cxl_port *__devm_cxl_add_port(struct device *host,
> port->reg_map = cxlds->reg_map;
> port->reg_map.host = &port->dev;
> cxlmd->endpoint = port;
> + port->capabilities = cxlds->capabilities;
> } else if (parent_dport) {
> rc = dev_set_name(dev, "port%d", port->id);
> if (rc)
> diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
> index e1082e749c69..8b8abcadcb93 100644
> --- a/drivers/cxl/core/regs.c
> +++ b/drivers/cxl/core/regs.c
> @@ -1,6 +1,7 @@
> // SPDX-License-Identifier: GPL-2.0-only
> /* Copyright(c) 2020 Intel Corporation. */
> #include <linux/io-64-nonatomic-lo-hi.h>
> +#include <linux/cxl/cxl.h>
> #include <linux/device.h>
> #include <linux/slab.h>
> #include <linux/pci.h>
> @@ -36,7 +37,7 @@
> * Probe for component register information and return it in map object.
> */
> void cxl_probe_component_regs(struct device *dev, void __iomem *base,
> - struct cxl_component_reg_map *map)
> + struct cxl_component_reg_map *map, u32 *caps)
> {
> int cap, cap_count;
> u32 cap_array;
> @@ -84,6 +85,7 @@ void cxl_probe_component_regs(struct device *dev, void __iomem *base,
> decoder_cnt = cxl_hdm_decoder_count(hdr);
> length = 0x20 * decoder_cnt + 0x10;
> rmap = &map->hdm_decoder;
> + *caps |= BIT(CXL_DEV_CAP_HDM);
> break;
> }
> case CXL_CM_CAP_CAP_ID_RAS:
> @@ -91,6 +93,7 @@ void cxl_probe_component_regs(struct device *dev, void __iomem *base,
> offset);
> length = CXL_RAS_CAPABILITY_LENGTH;
> rmap = &map->ras;
> + *caps |= BIT(CXL_DEV_CAP_RAS);
> break;
> default:
> dev_dbg(dev, "Unknown CM cap ID: %d (0x%x)\n", cap_id,
> @@ -117,7 +120,7 @@ EXPORT_SYMBOL_NS_GPL(cxl_probe_component_regs, CXL);
> * Probe for device register information and return it in map object.
> */
> void cxl_probe_device_regs(struct device *dev, void __iomem *base,
> - struct cxl_device_reg_map *map)
> + struct cxl_device_reg_map *map, u32 *caps)
> {
> int cap, cap_count;
> u64 cap_array;
> @@ -146,10 +149,12 @@ void cxl_probe_device_regs(struct device *dev, void __iomem *base,
> case CXLDEV_CAP_CAP_ID_DEVICE_STATUS:
> dev_dbg(dev, "found Status capability (0x%x)\n", offset);
> rmap = &map->status;
> + *caps |= BIT(CXL_DEV_CAP_DEV_STATUS);
> break;
> case CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX:
> dev_dbg(dev, "found Mailbox capability (0x%x)\n", offset);
> rmap = &map->mbox;
> + *caps |= BIT(CXL_DEV_CAP_MAILBOX_PRIMARY);
> break;
> case CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX:
> dev_dbg(dev, "found Secondary Mailbox capability (0x%x)\n", offset);
> @@ -157,6 +162,7 @@ void cxl_probe_device_regs(struct device *dev, void __iomem *base,
> case CXLDEV_CAP_CAP_ID_MEMDEV:
> dev_dbg(dev, "found Memory Device capability (0x%x)\n", offset);
> rmap = &map->memdev;
> + *caps |= BIT(CXL_DEV_CAP_MEMDEV);
> break;
> default:
> if (cap_id >= 0x8000)
> @@ -421,7 +427,7 @@ static void cxl_unmap_regblock(struct cxl_register_map *map)
> map->base = NULL;
> }
>
> -static int cxl_probe_regs(struct cxl_register_map *map)
> +static int cxl_probe_regs(struct cxl_register_map *map, u32 *caps)
> {
> struct cxl_component_reg_map *comp_map;
> struct cxl_device_reg_map *dev_map;
> @@ -431,12 +437,12 @@ static int cxl_probe_regs(struct cxl_register_map *map)
> switch (map->reg_type) {
> case CXL_REGLOC_RBI_COMPONENT:
> comp_map = &map->component_map;
> - cxl_probe_component_regs(host, base, comp_map);
> + cxl_probe_component_regs(host, base, comp_map, caps);
> dev_dbg(host, "Set up component registers\n");
> break;
> case CXL_REGLOC_RBI_MEMDEV:
> dev_map = &map->device_map;
> - cxl_probe_device_regs(host, base, dev_map);
> + cxl_probe_device_regs(host, base, dev_map, caps);
> if (!dev_map->status.valid || !dev_map->mbox.valid ||
> !dev_map->memdev.valid) {
> dev_err(host, "registers not found: %s%s%s\n",
> @@ -455,7 +461,7 @@ static int cxl_probe_regs(struct cxl_register_map *map)
> return 0;
> }
>
> -int cxl_setup_regs(struct cxl_register_map *map)
> +int cxl_setup_regs(struct cxl_register_map *map, u32 *caps)
> {
> int rc;
>
> @@ -463,7 +469,7 @@ int cxl_setup_regs(struct cxl_register_map *map)
> if (rc)
> return rc;
>
> - rc = cxl_probe_regs(map);
> + rc = cxl_probe_regs(map, caps);
> cxl_unmap_regblock(map);
>
> return rc;
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 9afb407d438f..07c153aa3d77 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -284,9 +284,9 @@ struct cxl_register_map {
> };
>
> void cxl_probe_component_regs(struct device *dev, void __iomem *base,
> - struct cxl_component_reg_map *map);
> + struct cxl_component_reg_map *map, u32 *caps);
> void cxl_probe_device_regs(struct device *dev, void __iomem *base,
> - struct cxl_device_reg_map *map);
> + struct cxl_device_reg_map *map, u32 *caps);
> int cxl_map_component_regs(const struct cxl_register_map *map,
> struct cxl_component_regs *regs,
> unsigned long map_mask);
> @@ -300,7 +300,7 @@ int cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type,
> struct cxl_register_map *map, int index);
> int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
> struct cxl_register_map *map);
> -int cxl_setup_regs(struct cxl_register_map *map);
> +int cxl_setup_regs(struct cxl_register_map *map, u32 *caps);
> struct cxl_dport;
> resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
> struct cxl_dport *dport);
> @@ -600,6 +600,7 @@ struct cxl_dax_region {
> * @cdat: Cached CDAT data
> * @cdat_available: Should a CDAT attribute be available in sysfs
> * @pci_latency: Upstream latency in picoseconds
> + * @capabilities: those capabilities as defined in device mapped registers
> */
> struct cxl_port {
> struct device dev;
> @@ -623,6 +624,7 @@ struct cxl_port {
> } cdat;
> bool cdat_available;
> long pci_latency;
> + u32 capabilities;
> };
>
> /**
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index afb53d058d62..37c043100300 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -424,6 +424,7 @@ struct cxl_dpa_perf {
> * @ram_res: Active Volatile memory capacity configuration
> * @serial: PCIe Device Serial Number
> * @type: Generic Memory Class device or Vendor Specific Memory device
> + * @capabilities: those capabilities as defined in device mapped registers
> */
> struct cxl_dev_state {
> struct device *dev;
> @@ -438,6 +439,7 @@ struct cxl_dev_state {
> struct resource ram_res;
> u64 serial;
> enum cxl_devtype type;
> + u32 capabilities;
> };
>
> /**
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index 742a7b2a1be5..58f325019886 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -503,7 +503,7 @@ static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
> }
>
> static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
> - struct cxl_register_map *map)
> + struct cxl_register_map *map, u32 *caps)
> {
> int rc;
>
> @@ -520,7 +520,7 @@ static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
> if (rc)
> return rc;
>
> - return cxl_setup_regs(map);
> + return cxl_setup_regs(map, caps);
> }
>
> static int cxl_pci_ras_unmask(struct pci_dev *pdev)
> @@ -827,7 +827,8 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> else
> cxl_set_dvsec(cxlds, dvsec);
>
> - rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
> + rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map,
> + &cxlds->capabilities);
> if (rc)
> return rc;
>
> @@ -840,7 +841,7 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> * still be useful for management functions so don't return an error.
> */
> rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT,
> - &cxlds->reg_map);
> + &cxlds->reg_map, &cxlds->capabilities);
> if (rc)
> dev_warn(&pdev->dev, "No component registers (%d)\n", rc);
> else if (!cxlds->reg_map.component_map.ras.valid)
> diff --git a/include/linux/cxl/cxl.h b/include/linux/cxl/cxl.h
> index e78eefa82123..930b1b9c1d6a 100644
> --- a/include/linux/cxl/cxl.h
> +++ b/include/linux/cxl/cxl.h
> @@ -12,6 +12,36 @@ enum cxl_resource {
> CXL_ACCEL_RES_PMEM,
> };
>
> +/* Capabilities as defined for:
> + *
> + * Component Registers (Table 8-22 CXL 3.0 specification)
> + * Device Registers (8.2.8.2.1 CXL 3.0 specification)

Should just use 3.1 since that's the latest spec.

> + */
> +
> +enum cxl_dev_cap {
> + /* capabilities from Component Registers */
> + CXL_DEV_CAP_RAS,
> + CXL_DEV_CAP_SEC,
> + CXL_DEV_CAP_LINK,
> + CXL_DEV_CAP_HDM,
> + CXL_DEV_CAP_SEC_EXT,
> + CXL_DEV_CAP_IDE,
> + CXL_DEV_CAP_SNOOP_FILTER,
> + CXL_DEV_CAP_TIMEOUT_AND_ISOLATION,
> + CXL_DEV_CAP_CACHEMEM_EXT,
> + CXL_DEV_CAP_BI_ROUTE_TABLE,
> + CXL_DEV_CAP_BI_DECODER,
> + CXL_DEV_CAP_CACHEID_ROUTE_TABLE,
> + CXL_DEV_CAP_CACHEID_DECODER,
> + CXL_DEV_CAP_HDM_EXT,
> + CXL_DEV_CAP_METADATA_EXT,
> + /* capabilities from Device Registers */
> + CXL_DEV_CAP_DEV_STATUS,
> + CXL_DEV_CAP_MAILBOX_PRIMARY,
> + CXL_DEV_CAP_MAILBOX_SECONDARY,

Does the OS ever uses the SECONDARY mailbox?

> + CXL_DEV_CAP_MEMDEV,
> +};
> +
> struct cxl_dev_state *cxl_accel_state_create(struct device *dev);
>
> void cxl_set_dvsec(struct cxl_dev_state *cxlds, u16 dvsec);