From 37d1ade89606875c9cd6eb3b4ee416b7e1800fc4 Mon Sep 17 00:00:00 2001 From: Hans Zhang <18255117159@163.com> Date: Wed, 13 Aug 2025 22:45:24 +0800 Subject: [PATCH 1/7] PCI: Clean up __pci_find_next_cap_ttl() readability Refactor the __pci_find_next_cap_ttl() to improve code clarity: - Replace magic number 0x40 with PCI_STD_HEADER_SIZEOF. - Use ALIGN_DOWN() for position alignment instead of manual bitmask. - Extract PCI capability fields via FIELD_GET() with standardized masks. - Add necessary headers (linux/align.h). No functional changes intended. Signed-off-by: Hans Zhang <18255117159@163.com> Signed-off-by: Bjorn Helgaas Tested-by: Niklas Schnelle Acked-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20250813144529.303548-2-18255117159@163.com --- drivers/pci/pci.c | 9 +++++---- include/uapi/linux/pci_regs.h | 3 +++ 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b0f4d98036cd..40a5c87d9a6b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -9,6 +9,7 @@ */ #include +#include #include #include #include @@ -432,17 +433,17 @@ static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, pci_bus_read_config_byte(bus, devfn, pos, &pos); while ((*ttl)--) { - if (pos < 0x40) + if (pos < PCI_STD_HEADER_SIZEOF) break; - pos &= ~3; + pos = ALIGN_DOWN(pos, 4); pci_bus_read_config_word(bus, devfn, pos, &ent); - id = ent & 0xff; + id = FIELD_GET(PCI_CAP_ID_MASK, ent); if (id == 0xff) break; if (id == cap) return pos; - pos = (ent >> 8); + pos = FIELD_GET(PCI_CAP_LIST_NEXT_MASK, ent); } return 0; } diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index f5b17745de60..1bba99b46227 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -207,6 +207,9 @@ /* Capability lists */ +#define PCI_CAP_ID_MASK 0x00ff /* Capability ID mask */ +#define PCI_CAP_LIST_NEXT_MASK 0xff00 /* Next Capability Pointer mask */ + #define PCI_CAP_LIST_ID 0 /* Capability ID */ #define PCI_CAP_ID_PM 0x01 /* Power Management */ #define PCI_CAP_ID_AGP 0x02 /* Accelerated Graphics Port */ From 3c02084d8fa521192ea19722b1e5efae8096d939 Mon Sep 17 00:00:00 2001 From: Hans Zhang <18255117159@163.com> Date: Wed, 13 Aug 2025 22:45:25 +0800 Subject: [PATCH 2/7] PCI: Refactor capability search into PCI_FIND_NEXT_CAP() The PCI Capability search functionality is duplicated across the PCI core and several controller drivers. The core's current implementation requires fully initialized PCI device and bus structures, which prevents controller drivers from using it during early initialization phases before these structures are available. Move the Capability search logic into a PCI_FIND_NEXT_CAP() macro that accepts a config space accessor function as an argument. This enables controller drivers to perform Capability discovery using their early access mechanisms prior to full device initialization while sharing the Capability search code. Convert the existing PCI core Capability search implementation to use PCI_FIND_NEXT_CAP(). Controller drivers can later use this with their early access mechanisms while maintaining the existing protection against infinite loops through preserved TTL checks. Signed-off-by: Hans Zhang <18255117159@163.com> Signed-off-by: Bjorn Helgaas Tested-by: Niklas Schnelle Link: https://patch.msgid.link/20250813144529.303548-3-18255117159@163.com --- drivers/pci/pci.c | 42 ++++++++---------------------------------- drivers/pci/pci.h | 45 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 53 insertions(+), 34 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 40a5c87d9a6b..ac2658d946ea 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -9,7 +9,6 @@ */ #include -#include #include #include #include @@ -424,36 +423,10 @@ found: return 1; } -static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, - u8 pos, int cap, int *ttl) -{ - u8 id; - u16 ent; - - pci_bus_read_config_byte(bus, devfn, pos, &pos); - - while ((*ttl)--) { - if (pos < PCI_STD_HEADER_SIZEOF) - break; - pos = ALIGN_DOWN(pos, 4); - pci_bus_read_config_word(bus, devfn, pos, &ent); - - id = FIELD_GET(PCI_CAP_ID_MASK, ent); - if (id == 0xff) - break; - if (id == cap) - return pos; - pos = FIELD_GET(PCI_CAP_LIST_NEXT_MASK, ent); - } - return 0; -} - static u8 __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn, u8 pos, int cap) { - int ttl = PCI_FIND_CAP_TTL; - - return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl); + return PCI_FIND_NEXT_CAP(pci_bus_read_config, pos, cap, bus, devfn); } u8 pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap) @@ -649,7 +622,7 @@ EXPORT_SYMBOL_GPL(pci_get_dsn); static u8 __pci_find_next_ht_cap(struct pci_dev *dev, u8 pos, int ht_cap) { - int rc, ttl = PCI_FIND_CAP_TTL; + int rc; u8 cap, mask; if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST) @@ -657,8 +630,8 @@ static u8 __pci_find_next_ht_cap(struct pci_dev *dev, u8 pos, int ht_cap) else mask = HT_5BIT_CAP_MASK; - pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos, - PCI_CAP_ID_HT, &ttl); + pos = PCI_FIND_NEXT_CAP(pci_bus_read_config, pos, + PCI_CAP_ID_HT, dev->bus, dev->devfn); while (pos) { rc = pci_read_config_byte(dev, pos + 3, &cap); if (rc != PCIBIOS_SUCCESSFUL) @@ -667,9 +640,10 @@ static u8 __pci_find_next_ht_cap(struct pci_dev *dev, u8 pos, int ht_cap) if ((cap & mask) == ht_cap) return pos; - pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, - pos + PCI_CAP_LIST_NEXT, - PCI_CAP_ID_HT, &ttl); + pos = PCI_FIND_NEXT_CAP(pci_bus_read_config, + pos + PCI_CAP_LIST_NEXT, + PCI_CAP_ID_HT, dev->bus, + dev->devfn); } return 0; diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 34f65d69662e..81580987509f 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -2,6 +2,8 @@ #ifndef DRIVERS_PCI_H #define DRIVERS_PCI_H +#include +#include #include struct pcie_tlp_log; @@ -88,6 +90,49 @@ bool pcie_cap_has_lnkctl(const struct pci_dev *dev); bool pcie_cap_has_lnkctl2(const struct pci_dev *dev); bool pcie_cap_has_rtctl(const struct pci_dev *dev); +/* Standard Capability finder */ +/** + * PCI_FIND_NEXT_CAP - Find a PCI standard capability + * @read_cfg: Function pointer for reading PCI config space + * @start: Starting position to begin search + * @cap: Capability ID to find + * @args: Arguments to pass to read_cfg function + * + * Search the capability list in PCI config space to find @cap. + * Implements TTL (time-to-live) protection against infinite loops. + * + * Return: Position of the capability if found, 0 otherwise. + */ +#define PCI_FIND_NEXT_CAP(read_cfg, start, cap, args...) \ +({ \ + int __ttl = PCI_FIND_CAP_TTL; \ + u8 __id, __found_pos = 0; \ + u8 __pos = (start); \ + u16 __ent; \ + \ + read_cfg##_byte(args, __pos, &__pos); \ + \ + while (__ttl--) { \ + if (__pos < PCI_STD_HEADER_SIZEOF) \ + break; \ + \ + __pos = ALIGN_DOWN(__pos, 4); \ + read_cfg##_word(args, __pos, &__ent); \ + \ + __id = FIELD_GET(PCI_CAP_ID_MASK, __ent); \ + if (__id == 0xff) \ + break; \ + \ + if (__id == (cap)) { \ + __found_pos = __pos; \ + break; \ + } \ + \ + __pos = FIELD_GET(PCI_CAP_LIST_NEXT_MASK, __ent); \ + } \ + __found_pos; \ +}) + /* Functions internal to the PCI core code */ #ifdef CONFIG_DMI From 4d909bf1a53eb1e2e4d523a8d6f66532ac1bae0b Mon Sep 17 00:00:00 2001 From: Hans Zhang <18255117159@163.com> Date: Wed, 13 Aug 2025 22:45:26 +0800 Subject: [PATCH 3/7] PCI: Refactor extended capability search into PCI_FIND_NEXT_EXT_CAP() Move the extended Capability search logic into a PCI_FIND_NEXT_EXT_CAP() macro that accepts a config space accessor function as an argument. This enables controller drivers to perform Capability discovery using their early access mechanisms prior to full device initialization while sharing the Capability search code. Convert the existing PCI core extended Capability search implementation to use PCI_FIND_NEXT_EXT_CAP(). Signed-off-by: Hans Zhang <18255117159@163.com> Signed-off-by: Bjorn Helgaas Tested-by: Niklas Schnelle Link: https://patch.msgid.link/20250813144529.303548-4-18255117159@163.com --- drivers/pci/pci.c | 35 ++--------------------------------- drivers/pci/pci.h | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+), 33 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index ac2658d946ea..e698278229f2 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -527,42 +527,11 @@ EXPORT_SYMBOL(pci_bus_find_capability); */ u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 start, int cap) { - u32 header; - int ttl; - u16 pos = PCI_CFG_SPACE_SIZE; - - /* minimum 8 bytes per capability */ - ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8; - if (dev->cfg_size <= PCI_CFG_SPACE_SIZE) return 0; - if (start) - pos = start; - - if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL) - return 0; - - /* - * If we have no capabilities, this is indicated by cap ID, - * cap version and next pointer all being 0. - */ - if (header == 0) - return 0; - - while (ttl-- > 0) { - if (PCI_EXT_CAP_ID(header) == cap && pos != start) - return pos; - - pos = PCI_EXT_CAP_NEXT(header); - if (pos < PCI_CFG_SPACE_SIZE) - break; - - if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL) - break; - } - - return 0; + return PCI_FIND_NEXT_EXT_CAP(pci_bus_read_config, start, cap, + dev->bus, dev->devfn); } EXPORT_SYMBOL_GPL(pci_find_next_ext_capability); diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 81580987509f..7fb44faf2c44 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -133,6 +133,46 @@ bool pcie_cap_has_rtctl(const struct pci_dev *dev); __found_pos; \ }) +/* Extended Capability finder */ +/** + * PCI_FIND_NEXT_EXT_CAP - Find a PCI extended capability + * @read_cfg: Function pointer for reading PCI config space + * @start: Starting position to begin search (0 for initial search) + * @cap: Extended capability ID to find + * @args: Arguments to pass to read_cfg function + * + * Search the extended capability list in PCI config space to find @cap. + * Implements TTL protection against infinite loops using a calculated + * maximum search count. + * + * Return: Position of the capability if found, 0 otherwise. + */ +#define PCI_FIND_NEXT_EXT_CAP(read_cfg, start, cap, args...) \ +({ \ + u16 __pos = (start) ?: PCI_CFG_SPACE_SIZE; \ + u16 __found_pos = 0; \ + int __ttl, __ret; \ + u32 __header; \ + \ + __ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8; \ + while (__ttl-- > 0 && __pos >= PCI_CFG_SPACE_SIZE) { \ + __ret = read_cfg##_dword(args, __pos, &__header); \ + if (__ret != PCIBIOS_SUCCESSFUL) \ + break; \ + \ + if (__header == 0) \ + break; \ + \ + if (PCI_EXT_CAP_ID(__header) == (cap) && __pos != start) {\ + __found_pos = __pos; \ + break; \ + } \ + \ + __pos = PCI_EXT_CAP_NEXT(__header); \ + } \ + __found_pos; \ +}) + /* Functions internal to the PCI core code */ #ifdef CONFIG_DMI From 8ffc9f234fdf332310015d507ae22db9a2820d37 Mon Sep 17 00:00:00 2001 From: Hans Zhang <18255117159@163.com> Date: Wed, 13 Aug 2025 22:45:27 +0800 Subject: [PATCH 4/7] PCI: dwc: Implement capability search using PCI core APIs The PCI core now provides generic PCI_FIND_NEXT_CAP() and PCI_FIND_NEXT_EXT_CAP() macros to search for PCI capabilities, using config accessors we supply. Use them in the DWC driver to implement dw_pcie_find_capability() and dw_pcie_find_ext_capability() instead of duplicating the algorithm. Signed-off-by: Hans Zhang <18255117159@163.com> [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20250813144529.303548-5-18255117159@163.com --- drivers/pci/controller/dwc/pcie-designware.c | 77 ++------------------ drivers/pci/controller/dwc/pcie-designware.h | 21 ++++++ 2 files changed, 26 insertions(+), 72 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 89aad5a08928..5fe0744d4235 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -213,83 +213,16 @@ void dw_pcie_version_detect(struct dw_pcie *pci) pci->type = ver; } -/* - * These interfaces resemble the pci_find_*capability() interfaces, but these - * are for configuring host controllers, which are bridges *to* PCI devices but - * are not PCI devices themselves. - */ -static u8 __dw_pcie_find_next_cap(struct dw_pcie *pci, u8 cap_ptr, - u8 cap) -{ - u8 cap_id, next_cap_ptr; - u16 reg; - - if (!cap_ptr) - return 0; - - reg = dw_pcie_readw_dbi(pci, cap_ptr); - cap_id = (reg & 0x00ff); - - if (cap_id > PCI_CAP_ID_MAX) - return 0; - - if (cap_id == cap) - return cap_ptr; - - next_cap_ptr = (reg & 0xff00) >> 8; - return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap); -} - u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap) { - u8 next_cap_ptr; - u16 reg; - - reg = dw_pcie_readw_dbi(pci, PCI_CAPABILITY_LIST); - next_cap_ptr = (reg & 0x00ff); - - return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap); + return PCI_FIND_NEXT_CAP(dw_pcie_read_cfg, PCI_CAPABILITY_LIST, cap, + pci); } EXPORT_SYMBOL_GPL(dw_pcie_find_capability); -static u16 dw_pcie_find_next_ext_capability(struct dw_pcie *pci, u16 start, - u8 cap) -{ - u32 header; - int ttl; - int pos = PCI_CFG_SPACE_SIZE; - - /* minimum 8 bytes per capability */ - ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8; - - if (start) - pos = start; - - header = dw_pcie_readl_dbi(pci, pos); - /* - * If we have no capabilities, this is indicated by cap ID, - * cap version and next pointer all being 0. - */ - if (header == 0) - return 0; - - while (ttl-- > 0) { - if (PCI_EXT_CAP_ID(header) == cap && pos != start) - return pos; - - pos = PCI_EXT_CAP_NEXT(header); - if (pos < PCI_CFG_SPACE_SIZE) - break; - - header = dw_pcie_readl_dbi(pci, pos); - } - - return 0; -} - u16 dw_pcie_find_ext_capability(struct dw_pcie *pci, u8 cap) { - return dw_pcie_find_next_ext_capability(pci, 0, cap); + return PCI_FIND_NEXT_EXT_CAP(dw_pcie_read_cfg, 0, cap, pci); } EXPORT_SYMBOL_GPL(dw_pcie_find_ext_capability); @@ -302,8 +235,8 @@ static u16 __dw_pcie_find_vsec_capability(struct dw_pcie *pci, u16 vendor_id, if (vendor_id != dw_pcie_readw_dbi(pci, PCI_VENDOR_ID)) return 0; - while ((vsec = dw_pcie_find_next_ext_capability(pci, vsec, - PCI_EXT_CAP_ID_VNDR))) { + while ((vsec = PCI_FIND_NEXT_EXT_CAP(dw_pcie_read_cfg, vsec, + PCI_EXT_CAP_ID_VNDR, pci))) { header = dw_pcie_readl_dbi(pci, vsec + PCI_VNDR_HEADER); if (PCI_VNDR_HEADER_ID(header) == vsec_id) return vsec; diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 00f52d472dcd..b5e7e18138a6 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -609,6 +609,27 @@ static inline void dw_pcie_writel_dbi2(struct dw_pcie *pci, u32 reg, u32 val) dw_pcie_write_dbi2(pci, reg, 0x4, val); } +static inline int dw_pcie_read_cfg_byte(struct dw_pcie *pci, int where, + u8 *val) +{ + *val = dw_pcie_readb_dbi(pci, where); + return PCIBIOS_SUCCESSFUL; +} + +static inline int dw_pcie_read_cfg_word(struct dw_pcie *pci, int where, + u16 *val) +{ + *val = dw_pcie_readw_dbi(pci, where); + return PCIBIOS_SUCCESSFUL; +} + +static inline int dw_pcie_read_cfg_dword(struct dw_pcie *pci, int where, + u32 *val) +{ + *val = dw_pcie_readl_dbi(pci, where); + return PCIBIOS_SUCCESSFUL; +} + static inline unsigned int dw_pcie_ep_get_dbi_offset(struct dw_pcie_ep *ep, u8 func_no) { From 3a33020d22bff1650af59314b6faea7efb04bf89 Mon Sep 17 00:00:00 2001 From: Hans Zhang <18255117159@163.com> Date: Tue, 19 Aug 2025 22:58:28 +0800 Subject: [PATCH 5/7] PCI: dwc: ep: Implement capability search using PCI core APIs The PCI core now provides generic PCI_FIND_NEXT_CAP() macros to search for PCI capabilities, using config accessors we supply. Use them in the DWC EP driver to implement dw_pcie_ep_find_capability() instead of duplicating the algorithm. Signed-off-by: Hans Zhang <18255117159@163.com> Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20250819145828.438541-1-18255117159@163.com --- .../pci/controller/dwc/pcie-designware-ep.c | 31 ++----------------- drivers/pci/controller/dwc/pcie-designware.h | 21 +++++++++++++ 2 files changed, 23 insertions(+), 29 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c index 0ae54a94809b..7f2112c2fb21 100644 --- a/drivers/pci/controller/dwc/pcie-designware-ep.c +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c @@ -69,37 +69,10 @@ void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar) } EXPORT_SYMBOL_GPL(dw_pcie_ep_reset_bar); -static u8 __dw_pcie_ep_find_next_cap(struct dw_pcie_ep *ep, u8 func_no, - u8 cap_ptr, u8 cap) -{ - u8 cap_id, next_cap_ptr; - u16 reg; - - if (!cap_ptr) - return 0; - - reg = dw_pcie_ep_readw_dbi(ep, func_no, cap_ptr); - cap_id = (reg & 0x00ff); - - if (cap_id > PCI_CAP_ID_MAX) - return 0; - - if (cap_id == cap) - return cap_ptr; - - next_cap_ptr = (reg & 0xff00) >> 8; - return __dw_pcie_ep_find_next_cap(ep, func_no, next_cap_ptr, cap); -} - static u8 dw_pcie_ep_find_capability(struct dw_pcie_ep *ep, u8 func_no, u8 cap) { - u8 next_cap_ptr; - u16 reg; - - reg = dw_pcie_ep_readw_dbi(ep, func_no, PCI_CAPABILITY_LIST); - next_cap_ptr = (reg & 0x00ff); - - return __dw_pcie_ep_find_next_cap(ep, func_no, next_cap_ptr, cap); + return PCI_FIND_NEXT_CAP(dw_pcie_ep_read_cfg, PCI_CAPABILITY_LIST, + cap, ep, func_no); } /** diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index b5e7e18138a6..a44f2113925d 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -695,6 +695,27 @@ static inline u8 dw_pcie_ep_readb_dbi(struct dw_pcie_ep *ep, u8 func_no, return dw_pcie_ep_read_dbi(ep, func_no, reg, 0x1); } +static inline int dw_pcie_ep_read_cfg_byte(struct dw_pcie_ep *ep, u8 func_no, + int where, u8 *val) +{ + *val = dw_pcie_ep_readb_dbi(ep, func_no, where); + return PCIBIOS_SUCCESSFUL; +} + +static inline int dw_pcie_ep_read_cfg_word(struct dw_pcie_ep *ep, u8 func_no, + int where, u16 *val) +{ + *val = dw_pcie_ep_readw_dbi(ep, func_no, where); + return PCIBIOS_SUCCESSFUL; +} + +static inline int dw_pcie_ep_read_cfg_dword(struct dw_pcie_ep *ep, u8 func_no, + int where, u32 *val) +{ + *val = dw_pcie_ep_readl_dbi(ep, func_no, where); + return PCIBIOS_SUCCESSFUL; +} + static inline unsigned int dw_pcie_ep_get_dbi2_offset(struct dw_pcie_ep *ep, u8 func_no) { From 18ac51ae9df925292a4d8ca6550a199924ae9e17 Mon Sep 17 00:00:00 2001 From: Hans Zhang <18255117159@163.com> Date: Wed, 13 Aug 2025 22:45:28 +0800 Subject: [PATCH 6/7] PCI: cadence: Implement capability search using PCI core APIs The PCI core now provides generic PCI_FIND_NEXT_CAP() and PCI_FIND_NEXT_EXT_CAP() macros to search for PCI capabilities, using config accessors we supply. Use them in the CDNS driver to add cdns_pcie_find_capability() and cdns_pcie_find_ext_capability() interfaces. Signed-off-by: Hans Zhang <18255117159@163.com> [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20250813144529.303548-6-18255117159@163.com --- drivers/pci/controller/cadence/pcie-cadence.c | 14 ++++++++ drivers/pci/controller/cadence/pcie-cadence.h | 34 +++++++++++++++++++ 2 files changed, 48 insertions(+) diff --git a/drivers/pci/controller/cadence/pcie-cadence.c b/drivers/pci/controller/cadence/pcie-cadence.c index 70a19573440e..c45585ae1746 100644 --- a/drivers/pci/controller/cadence/pcie-cadence.c +++ b/drivers/pci/controller/cadence/pcie-cadence.c @@ -8,6 +8,20 @@ #include #include "pcie-cadence.h" +#include "../../pci.h" + +u8 cdns_pcie_find_capability(struct cdns_pcie *pcie, u8 cap) +{ + return PCI_FIND_NEXT_CAP(cdns_pcie_read_cfg, PCI_CAPABILITY_LIST, + cap, pcie); +} +EXPORT_SYMBOL_GPL(cdns_pcie_find_capability); + +u16 cdns_pcie_find_ext_capability(struct cdns_pcie *pcie, u8 cap) +{ + return PCI_FIND_NEXT_EXT_CAP(cdns_pcie_read_cfg, 0, cap, pcie); +} +EXPORT_SYMBOL_GPL(cdns_pcie_find_ext_capability); void cdns_pcie_detect_quiet_min_delay_set(struct cdns_pcie *pcie) { diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h index 1d81c4bf6c6d..9eebf8f02abc 100644 --- a/drivers/pci/controller/cadence/pcie-cadence.h +++ b/drivers/pci/controller/cadence/pcie-cadence.h @@ -367,6 +367,37 @@ static inline u32 cdns_pcie_readl(struct cdns_pcie *pcie, u32 reg) return readl(pcie->reg_base + reg); } +static inline u16 cdns_pcie_readw(struct cdns_pcie *pcie, u32 reg) +{ + return readw(pcie->reg_base + reg); +} + +static inline u8 cdns_pcie_readb(struct cdns_pcie *pcie, u32 reg) +{ + return readb(pcie->reg_base + reg); +} + +static inline int cdns_pcie_read_cfg_byte(struct cdns_pcie *pcie, int where, + u8 *val) +{ + *val = cdns_pcie_readb(pcie, where); + return PCIBIOS_SUCCESSFUL; +} + +static inline int cdns_pcie_read_cfg_word(struct cdns_pcie *pcie, int where, + u16 *val) +{ + *val = cdns_pcie_readw(pcie, where); + return PCIBIOS_SUCCESSFUL; +} + +static inline int cdns_pcie_read_cfg_dword(struct cdns_pcie *pcie, int where, + u32 *val) +{ + *val = cdns_pcie_readl(pcie, where); + return PCIBIOS_SUCCESSFUL; +} + static inline u32 cdns_pcie_read_sz(void __iomem *addr, int size) { void __iomem *aligned_addr = PTR_ALIGN_DOWN(addr, 0x4); @@ -536,6 +567,9 @@ static inline void cdns_pcie_ep_disable(struct cdns_pcie_ep *ep) } #endif +u8 cdns_pcie_find_capability(struct cdns_pcie *pcie, u8 cap); +u16 cdns_pcie_find_ext_capability(struct cdns_pcie *pcie, u8 cap); + void cdns_pcie_detect_quiet_min_delay_set(struct cdns_pcie *pcie); void cdns_pcie_set_outbound_region(struct cdns_pcie *pcie, u8 busnr, u8 fn, From 907912c1daa7d87ec179ab35f6326e98233ae03a Mon Sep 17 00:00:00 2001 From: Hans Zhang <18255117159@163.com> Date: Wed, 13 Aug 2025 22:45:29 +0800 Subject: [PATCH 7/7] PCI: cadence: Use cdns_pcie_find_*capability() to avoid hardcoding offsets MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The PCI capability/extended capability offsets are not guaranteed to be the same across all SoCs integrating the Cadence PCIe IP. Use the cdns_pcie_find_{ext}_capability() APIs to find the capabilities, which avoids hardcoding the offsets in the driver. Signed-off-by: Hans Zhang <18255117159@163.com> Signed-off-by: Bjorn Helgaas Reviewed-by: Ilpo Järvinen Acked-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20250813144529.303548-7-18255117159@163.com --- .../pci/controller/cadence/pcie-cadence-ep.c | 38 +++++++++++-------- drivers/pci/controller/cadence/pcie-cadence.h | 5 --- 2 files changed, 22 insertions(+), 21 deletions(-) diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c index 77c5a19b2ab1..5529ed84649f 100644 --- a/drivers/pci/controller/cadence/pcie-cadence-ep.c +++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c @@ -21,12 +21,13 @@ static u8 cdns_pcie_get_fn_from_vfn(struct cdns_pcie *pcie, u8 fn, u8 vfn) { - u32 cap = CDNS_PCIE_EP_FUNC_SRIOV_CAP_OFFSET; u32 first_vf_offset, stride; + u16 cap; if (vfn == 0) return fn; + cap = cdns_pcie_find_ext_capability(pcie, PCI_EXT_CAP_ID_SRIOV); first_vf_offset = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_SRIOV_VF_OFFSET); stride = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_SRIOV_VF_STRIDE); fn = fn + first_vf_offset + ((vfn - 1) * stride); @@ -38,10 +39,11 @@ static int cdns_pcie_ep_write_header(struct pci_epc *epc, u8 fn, u8 vfn, struct pci_epf_header *hdr) { struct cdns_pcie_ep *ep = epc_get_drvdata(epc); - u32 cap = CDNS_PCIE_EP_FUNC_SRIOV_CAP_OFFSET; struct cdns_pcie *pcie = &ep->pcie; u32 reg; + u16 cap; + cap = cdns_pcie_find_ext_capability(pcie, PCI_EXT_CAP_ID_SRIOV); if (vfn > 1) { dev_err(&epc->dev, "Only Virtual Function #1 has deviceID\n"); return -EINVAL; @@ -227,9 +229,10 @@ static int cdns_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 vfn, u8 nr_irqs) struct cdns_pcie_ep *ep = epc_get_drvdata(epc); struct cdns_pcie *pcie = &ep->pcie; u8 mmc = order_base_2(nr_irqs); - u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET; u16 flags; + u8 cap; + cap = cdns_pcie_find_capability(pcie, PCI_CAP_ID_MSI); fn = cdns_pcie_get_fn_from_vfn(pcie, fn, vfn); /* @@ -249,9 +252,10 @@ static int cdns_pcie_ep_get_msi(struct pci_epc *epc, u8 fn, u8 vfn) { struct cdns_pcie_ep *ep = epc_get_drvdata(epc); struct cdns_pcie *pcie = &ep->pcie; - u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET; u16 flags, mme; + u8 cap; + cap = cdns_pcie_find_capability(pcie, PCI_CAP_ID_MSIX); fn = cdns_pcie_get_fn_from_vfn(pcie, fn, vfn); /* Validate that the MSI feature is actually enabled. */ @@ -272,9 +276,10 @@ static int cdns_pcie_ep_get_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no) { struct cdns_pcie_ep *ep = epc_get_drvdata(epc); struct cdns_pcie *pcie = &ep->pcie; - u32 cap = CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET; u32 val, reg; + u8 cap; + cap = cdns_pcie_find_capability(pcie, PCI_CAP_ID_MSIX); func_no = cdns_pcie_get_fn_from_vfn(pcie, func_no, vfunc_no); reg = cap + PCI_MSIX_FLAGS; @@ -292,9 +297,10 @@ static int cdns_pcie_ep_set_msix(struct pci_epc *epc, u8 fn, u8 vfn, { struct cdns_pcie_ep *ep = epc_get_drvdata(epc); struct cdns_pcie *pcie = &ep->pcie; - u32 cap = CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET; u32 val, reg; + u8 cap; + cap = cdns_pcie_find_capability(pcie, PCI_CAP_ID_MSIX); fn = cdns_pcie_get_fn_from_vfn(pcie, fn, vfn); reg = cap + PCI_MSIX_FLAGS; @@ -380,11 +386,11 @@ static int cdns_pcie_ep_send_msi_irq(struct cdns_pcie_ep *ep, u8 fn, u8 vfn, u8 interrupt_num) { struct cdns_pcie *pcie = &ep->pcie; - u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET; u16 flags, mme, data, data_mask; - u8 msi_count; u64 pci_addr, pci_addr_mask = 0xff; + u8 msi_count, cap; + cap = cdns_pcie_find_capability(pcie, PCI_CAP_ID_MSI); fn = cdns_pcie_get_fn_from_vfn(pcie, fn, vfn); /* Check whether the MSI feature has been enabled by the PCI host. */ @@ -432,14 +438,14 @@ static int cdns_pcie_ep_map_msi_irq(struct pci_epc *epc, u8 fn, u8 vfn, u32 *msi_addr_offset) { struct cdns_pcie_ep *ep = epc_get_drvdata(epc); - u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET; struct cdns_pcie *pcie = &ep->pcie; u64 pci_addr, pci_addr_mask = 0xff; u16 flags, mme, data, data_mask; - u8 msi_count; + u8 msi_count, cap; int ret; int i; + cap = cdns_pcie_find_capability(pcie, PCI_CAP_ID_MSI); fn = cdns_pcie_get_fn_from_vfn(pcie, fn, vfn); /* Check whether the MSI feature has been enabled by the PCI host. */ @@ -482,16 +488,16 @@ static int cdns_pcie_ep_map_msi_irq(struct pci_epc *epc, u8 fn, u8 vfn, static int cdns_pcie_ep_send_msix_irq(struct cdns_pcie_ep *ep, u8 fn, u8 vfn, u16 interrupt_num) { - u32 cap = CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET; u32 tbl_offset, msg_data, reg; struct cdns_pcie *pcie = &ep->pcie; struct pci_epf_msix_tbl *msix_tbl; struct cdns_pcie_epf *epf; u64 pci_addr_mask = 0xff; u64 msg_addr; + u8 bir, cap; u16 flags; - u8 bir; + cap = cdns_pcie_find_capability(pcie, PCI_CAP_ID_MSIX); epf = &ep->epf[fn]; if (vfn > 0) epf = &epf->epf[vfn - 1]; @@ -565,7 +571,9 @@ static int cdns_pcie_ep_start(struct pci_epc *epc) int max_epfs = sizeof(epc->function_num_map) * 8; int ret, epf, last_fn; u32 reg, value; + u8 cap; + cap = cdns_pcie_find_capability(pcie, PCI_CAP_ID_EXP); /* * BIT(0) is hardwired to 1, hence function 0 is always enabled * and can't be disabled anyway. @@ -589,12 +597,10 @@ static int cdns_pcie_ep_start(struct pci_epc *epc) continue; value = cdns_pcie_ep_fn_readl(pcie, epf, - CDNS_PCIE_EP_FUNC_DEV_CAP_OFFSET + - PCI_EXP_DEVCAP); + cap + PCI_EXP_DEVCAP); value &= ~PCI_EXP_DEVCAP_FLR; cdns_pcie_ep_fn_writel(pcie, epf, - CDNS_PCIE_EP_FUNC_DEV_CAP_OFFSET + - PCI_EXP_DEVCAP, value); + cap + PCI_EXP_DEVCAP, value); } } diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h index 9eebf8f02abc..88cec0dc2067 100644 --- a/drivers/pci/controller/cadence/pcie-cadence.h +++ b/drivers/pci/controller/cadence/pcie-cadence.h @@ -125,11 +125,6 @@ */ #define CDNS_PCIE_EP_FUNC_BASE(fn) (((fn) << 12) & GENMASK(19, 12)) -#define CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET 0x90 -#define CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET 0xb0 -#define CDNS_PCIE_EP_FUNC_DEV_CAP_OFFSET 0xc0 -#define CDNS_PCIE_EP_FUNC_SRIOV_CAP_OFFSET 0x200 - /* * Endpoint PF Registers */