From: Ben Widawsky <[email protected]> This implements the TODO in cxl_acpi for mapping component registers. cxl_acpi becomes the second consumer of CXL register block enumeration (cxl_pci being the first). Moving the functionality to cxl_core allows both of these drivers to use the functionality. Equally importantly it allows cxl_core to use the functionality in the future.
CXL 2.0 root ports are similar to CXL 2.0 Downstream Ports with the main distinction being they're a part of the CXL 2.0 host bridge. While mapping their component registers is not immediately useful for the CXL drivers, the movement of register block enumeration into core is a vital step towards HDM decoder programming. Signed-off-by: Ben Widawsky <[email protected]> Reviewed-by: Jonathan Cameron <[email protected]> [djbw: fix cxl_regmap_to_base() failure cases] Signed-off-by: Dan Williams <[email protected]> --- drivers/cxl/acpi.c | 13 +++++++++-- drivers/cxl/core/regs.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/cxl/cxl.h | 4 +++ drivers/cxl/pci.c | 52 -------------------------------------------- drivers/cxl/pci.h | 9 ++++++++ 5 files changed, 80 insertions(+), 54 deletions(-) diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index 3163167ecc3a..c656a49a11a9 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -7,6 +7,7 @@ #include <linux/acpi.h> #include <linux/pci.h> #include "cxl.h" +#include "pci.h" /* Encode defined in CXL 2.0 8.2.5.12.7 HDM Decoder Control Register */ #define CFMWS_INTERLEAVE_WAYS(x) (1 << (x)->interleave_ways) @@ -134,11 +135,13 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, __mock int match_add_root_ports(struct pci_dev *pdev, void *data) { + resource_size_t creg = CXL_RESOURCE_NONE; struct cxl_walk_context *ctx = data; struct pci_bus *root_bus = ctx->root; struct cxl_port *port = ctx->port; int type = pci_pcie_type(pdev); struct device *dev = ctx->dev; + struct cxl_register_map map; u32 lnkcap, port_num; int rc; @@ -152,9 +155,15 @@ __mock int match_add_root_ports(struct pci_dev *pdev, void *data) &lnkcap) != PCIBIOS_SUCCESSFUL) return 0; - /* TODO walk DVSEC to find component register base */ + /* The driver doesn't rely on component registers for Root Ports yet. */ + rc = cxl_find_regblock(pdev, CXL_REGLOC_RBI_COMPONENT, &map); + if (!rc) + dev_info(&pdev->dev, "No component register block found\n"); + + creg = cxl_regmap_to_base(pdev, &map); + port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap); - rc = cxl_add_dport(port, &pdev->dev, port_num, CXL_RESOURCE_NONE); + rc = cxl_add_dport(port, &pdev->dev, port_num, creg); if (rc) { ctx->error = rc; return rc; diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c index e37e23bf4355..0d63758e2605 100644 --- a/drivers/cxl/core/regs.c +++ b/drivers/cxl/core/regs.c @@ -5,6 +5,7 @@ #include <linux/slab.h> #include <linux/pci.h> #include <cxlmem.h> +#include <pci.h> /** * DOC: cxl registers @@ -247,3 +248,58 @@ int cxl_map_device_regs(struct pci_dev *pdev, return 0; } EXPORT_SYMBOL_NS_GPL(cxl_map_device_regs, CXL); + +static void cxl_decode_regblock(u32 reg_lo, u32 reg_hi, + struct cxl_register_map *map) +{ + map->block_offset = ((u64)reg_hi << 32) | + (reg_lo & CXL_DVSEC_REG_LOCATOR_BLOCK_OFF_LOW_MASK); + map->barno = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BIR_MASK, reg_lo); + map->reg_type = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BLOCK_ID_MASK, reg_lo); +} + +/** + * 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) +{ + u32 regloc_size, regblocks; + int regloc, i; + + map->block_offset = U64_MAX; + regloc = pci_find_dvsec_capability(pdev, PCI_DVSEC_VENDOR_ID_CXL, + CXL_DVSEC_REG_LOCATOR); + if (!regloc) + return -ENXIO; + + pci_read_config_dword(pdev, regloc + PCI_DVSEC_HEADER1, ®loc_size); + regloc_size = FIELD_GET(PCI_DVSEC_HEADER1_LENGTH_MASK, regloc_size); + + regloc += CXL_DVSEC_REG_LOCATOR_BLOCK1_OFFSET; + regblocks = (regloc_size - CXL_DVSEC_REG_LOCATOR_BLOCK1_OFFSET) / 8; + + for (i = 0; i < regblocks; i++, regloc += 8) { + u32 reg_lo, reg_hi; + + pci_read_config_dword(pdev, regloc, ®_lo); + pci_read_config_dword(pdev, regloc + 4, ®_hi); + + cxl_decode_regblock(reg_lo, reg_hi, map); + + if (map->reg_type == type) + return 0; + } + + map->block_offset = U64_MAX; + return -ENODEV; +} +EXPORT_SYMBOL_NS_GPL(cxl_find_regblock, CXL); diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index a5a0be3f088b..6288a6c1fc5c 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -145,6 +145,10 @@ int cxl_map_device_regs(struct pci_dev *pdev, struct cxl_device_regs *regs, struct cxl_register_map *map); +enum cxl_regloc_type; +int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type, + struct cxl_register_map *map); + #define CXL_RESOURCE_NONE ((resource_size_t) -1) #define CXL_TARGET_STRLEN 20 diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index 1eeba0ec46f3..bdfeb92ed028 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -367,58 +367,6 @@ static int cxl_map_regs(struct cxl_dev_state *cxlds, struct cxl_register_map *ma return 0; } -static void cxl_decode_regblock(u32 reg_lo, u32 reg_hi, - struct cxl_register_map *map) -{ - map->block_offset = ((u64)reg_hi << 32) | - (reg_lo & CXL_DVSEC_REG_LOCATOR_BLOCK_OFF_LOW_MASK); - map->barno = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BIR_MASK, reg_lo); - map->reg_type = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BLOCK_ID_MASK, reg_lo); -} - -/** - * 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. - */ -static int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type, - struct cxl_register_map *map) -{ - u32 regloc_size, regblocks; - int regloc, i; - - regloc = pci_find_dvsec_capability(pdev, PCI_DVSEC_VENDOR_ID_CXL, - CXL_DVSEC_REG_LOCATOR); - if (!regloc) - return -ENXIO; - - pci_read_config_dword(pdev, regloc + PCI_DVSEC_HEADER1, ®loc_size); - regloc_size = FIELD_GET(PCI_DVSEC_HEADER1_LENGTH_MASK, regloc_size); - - regloc += CXL_DVSEC_REG_LOCATOR_BLOCK1_OFFSET; - regblocks = (regloc_size - CXL_DVSEC_REG_LOCATOR_BLOCK1_OFFSET) / 8; - - for (i = 0; i < regblocks; i++, regloc += 8) { - u32 reg_lo, reg_hi; - - pci_read_config_dword(pdev, regloc, ®_lo); - pci_read_config_dword(pdev, regloc + 4, ®_hi); - - cxl_decode_regblock(reg_lo, reg_hi, map); - - if (map->reg_type == type) - return 0; - } - - return -ENODEV; -} - static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type, struct cxl_register_map *map) { diff --git a/drivers/cxl/pci.h b/drivers/cxl/pci.h index 8ae2b4adc59d..0623bb85f30a 100644 --- a/drivers/cxl/pci.h +++ b/drivers/cxl/pci.h @@ -47,4 +47,13 @@ enum cxl_regloc_type { CXL_REGLOC_RBI_TYPES }; +static inline resource_size_t cxl_regmap_to_base(struct pci_dev *pdev, + struct cxl_register_map *map) +{ + if (map->block_offset == U64_MAX) + return CXL_RESOURCE_NONE; + + return pci_resource_start(pdev, map->barno) + map->block_offset; +} + #endif /* __CXL_PCI_H__ */
