On 5/26/23 02:58, Jonathan Cameron wrote:
> Until the recently release CXL 3.0 specification, there
> was only ever one instance of any given register block pointed
> to by the Register Block Locator DVSEC. Now, the specification allows
> for multiple CXL PMU instances, each with their own register block.
>
> To enable this add cxl_find_regblock_instance() that takes an index
> parameter and use that to implement cxl_count_regblock() and
> cxl_find_regblock().
>
> Signed-off-by: Jonathan Cameron <[email protected]>
Reviewed-by: Dave Jiang <[email protected]>
> ---
> drivers/cxl/core/regs.c | 59 ++++++++++++++++++++++++++++++++++++-----
> drivers/cxl/cxl.h | 3 +++
> 2 files changed, 56 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
> index 1476a0299c9b..4b9672db867d 100644
> --- a/drivers/cxl/core/regs.c
> +++ b/drivers/cxl/core/regs.c
> @@ -286,20 +286,23 @@ static bool cxl_decode_regblock(struct pci_dev *pdev, u32 reg_lo, u32 reg_hi,
> }
>
> /**
> - * cxl_find_regblock() - Locate register blocks by type
> + * cxl_find_regblock_instance() - Locate a register block by type / index
> * @pdev: The CXL PCI device to enumerate.
> * @type: Register Block Indicator id
> * @map: Enumeration output, clobbered on error
> + * @index: Index into which particular instance of a regblock wanted in the
> + * order found in register locator DVSEC.
> *
> * Return: 0 if register block enumerated, negative error code otherwise
> *
> * A CXL DVSEC may point to one or more register blocks, search for them
> - * by @type.
> + * by @type and @index.
> */
> -int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
> - struct cxl_register_map *map)
> +int cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type,
> + struct cxl_register_map *map, int index)
> {
> u32 regloc_size, regblocks;
> + int instance = 0;
> int regloc, i;
>
> map->resource = CXL_RESOURCE_NONE;
> @@ -323,15 +326,59 @@ int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
> if (!cxl_decode_regblock(pdev, reg_lo, reg_hi, map))
> continue;
>
> - if (map->reg_type == type)
> - return 0;
> + if (map->reg_type == type) {
> + if (index == instance)
> + return 0;
> + instance++;
> + }
> }
>
> map->resource = CXL_RESOURCE_NONE;
> return -ENODEV;
> }
> +EXPORT_SYMBOL_NS_GPL(cxl_find_regblock_instance, CXL);
> +
> +/**
> + * cxl_find_regblock() - Locate register blocks by type
> + * @pdev: The CXL PCI device to enumerate.
> + * @type: Register Block Indicator id
> + * @map: Enumeration output, clobbered on error
> + *
> + * Return: 0 if register block enumerated, negative error code otherwise
> + *
> + * A CXL DVSEC may point to one or more register blocks, search for them
> + * by @type.
> + */
> +int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
> + struct cxl_register_map *map)
> +{
> + return cxl_find_regblock_instance(pdev, type, map, 0);
> +}
> EXPORT_SYMBOL_NS_GPL(cxl_find_regblock, CXL);
>
> +/**
> + * cxl_count_regblock() - Count instances of a given regblock type.
> + * @pdev: The CXL PCI device to enumerate.
> + * @type: Register Block Indicator id
> + *
> + * Some regblocks may be repeated. Count how many instances.
> + *
> + * Return: count of matching regblocks.
> + */
> +int cxl_count_regblock(struct pci_dev *pdev, enum cxl_regloc_type type)
> +{
> + struct cxl_register_map map;
> + int rc, count = 0;
> +
> + while (1) {
> + rc = cxl_find_regblock_instance(pdev, type, &map, count);
> + if (rc)
> + return count;
> + count++;
> + }
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_count_regblock, CXL);
> +
> resource_size_t cxl_rcrb_to_component(struct device *dev,
> resource_size_t rcrb,
> enum cxl_rcrb which)
> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
> index 044a92d9813e..f6e2a9ea5f41 100644
> --- a/drivers/cxl/cxl.h
> +++ b/drivers/cxl/cxl.h
> @@ -260,6 +260,9 @@ int cxl_map_device_regs(struct device *dev, struct cxl_device_regs *regs,
> struct cxl_register_map *map);
>
> enum cxl_regloc_type;
> +int cxl_count_regblock(struct pci_dev *pdev, enum cxl_regloc_type type);
> +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);
>