* [v3 1/4] PCI: Introduce generic capability search functions
2025-03-21 4:03 [v3 0/4] Introduce generic capability search functions Hans Zhang
@ 2025-03-21 4:03 ` Hans Zhang
2025-03-21 9:37 ` kernel test robot
` (2 more replies)
2025-03-21 4:03 ` [v3 2/4] PCI: dwc: Replace dw_pcie_find_capability() and dw_pcie_find_ext_capability() Hans Zhang
` (2 subsequent siblings)
3 siblings, 3 replies; 8+ messages in thread
From: Hans Zhang @ 2025-03-21 4:03 UTC (permalink / raw)
To: lpieralisi
Cc: kw, manivannan.sadhasivam, robh, bhelgaas, jingoohan1,
thomas.richard, linux-pci, linux-kernel, Hans Zhang
Existing controller drivers (e.g., DWC, custom out-of-tree drivers)
duplicate logic for scanning PCI capability lists. This creates
maintenance burdens and risks inconsistencies.
To resolve this:
1. Add pci_generic_find_capability() and pci_generic_find_ext_capability()
in drivers/pci/pci.c, accepting controller-specific read functions
and device data as parameters.
2. Refactor dwc_pcie_find_capability() and similar functions to utilize
these new generic interfaces.
3. Update out-of-tree drivers to leverage the common implementation,
eliminating code duplication.
This approach:
- Centralizes critical PCI capability scanning logic
- Allows flexible adaptation to varied hardware access methods
- Reduces future maintenance overhead
- Aligns with kernel code reuse best practices
Tested with DWC PCIe controller and CDNS PCIe drivers.
Signed-off-by: Hans Zhang <18255117159@163.com>
---
drivers/pci/pci.c | 83 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/pci.h | 13 ++++++-
2 files changed, 95 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 869d204a70a3..d686d89d211e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -612,6 +612,89 @@ u16 pci_find_ext_capability(struct pci_dev *dev, int cap)
}
EXPORT_SYMBOL_GPL(pci_find_ext_capability);
+/*
+ * 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 __pci_generic_find_next_cap(void *priv, pci_generic_read_cfg read_cfg,
+ u8 cap_ptr, u8 cap)
+{
+ u8 cap_id, next_cap_ptr;
+ u16 reg;
+
+ if (!cap_ptr)
+ return 0;
+
+ reg = read_cfg(priv, cap_ptr, 2);
+ 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 __pci_generic_find_next_cap(priv, read_cfg, next_cap_ptr, cap);
+}
+
+u8 pci_generic_find_capability(void *priv, pci_generic_read_cfg read_cfg,
+ u8 cap)
+{
+ u8 next_cap_ptr;
+ u16 reg;
+
+ reg = read_cfg(priv, PCI_CAPABILITY_LIST, 2);
+ next_cap_ptr = (reg & 0x00ff);
+
+ return __pci_generic_find_next_cap(priv, read_cfg, next_cap_ptr, cap);
+}
+EXPORT_SYMBOL_GPL(pci_generic_find_capability);
+
+static u16 pci_generic_find_next_ext_capability(void *priv,
+ pci_generic_read_cfg read_cfg,
+ 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 = read_cfg(priv, pos, 4);
+ /*
+ * 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 = read_cfg(priv, pos, 4);
+ }
+
+ return 0;
+}
+
+u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
+ int cap)
+{
+ return pci_generic_find_next_ext_capability(priv, read_cfg, 0, cap);
+}
+EXPORT_SYMBOL_GPL(pci_generic_find_ext_capability);
+
/**
* pci_get_dsn - Read and return the 8-byte Device Serial Number
* @dev: PCI device to query
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 47b31ad724fa..48c2b45a4d04 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1205,6 +1205,11 @@ u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap);
u8 pci_find_next_ht_capability(struct pci_dev *dev, u8 pos, int ht_cap);
u16 pci_find_ext_capability(struct pci_dev *dev, int cap);
u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 pos, int cap);
+typedef u32 (*pci_generic_read_cfg)(void *priv, int where, int size);
+u8 pci_generic_find_capability(void *priv, pci_generic_read_cfg read_cfg,
+ u8 cap);
+u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
+ u8 cap);
struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap);
u16 pci_find_dvsec_capability(struct pci_dev *dev, u16 vendor, u16 dvsec);
@@ -2012,7 +2017,13 @@ static inline u8 pci_find_next_capability(struct pci_dev *dev, u8 post, int cap)
{ return 0; }
static inline u16 pci_find_ext_capability(struct pci_dev *dev, int cap)
{ return 0; }
-
+typedef u32 (*pci_generic_read_cfg)(void *priv, int where, int size);
+u8 pci_generic_find_capability(void *priv, pci_generic_read_cfg read_cfg,
+ u8 cap)
+{ return 0; }
+u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
+ u8 cap)
+{ return 0; }
static inline u64 pci_get_dsn(struct pci_dev *dev)
{ return 0; }
--
2.25.1
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [v3 1/4] PCI: Introduce generic capability search functions
2025-03-21 4:03 ` [v3 1/4] PCI: " Hans Zhang
@ 2025-03-21 9:37 ` kernel test robot
2025-03-21 9:37 ` kernel test robot
2025-03-21 9:49 ` kernel test robot
2 siblings, 0 replies; 8+ messages in thread
From: kernel test robot @ 2025-03-21 9:37 UTC (permalink / raw)
To: Hans Zhang, lpieralisi
Cc: oe-kbuild-all, kw, manivannan.sadhasivam, robh, bhelgaas,
jingoohan1, thomas.richard, linux-pci, linux-kernel, Hans Zhang
Hi Hans,
kernel test robot noticed the following build errors:
[auto build test ERROR on a1cffe8cc8aef85f1b07c4464f0998b9785b795a]
url: https://github.com/intel-lab-lkp/linux/commits/Hans-Zhang/PCI-Introduce-generic-capability-search-functions/20250321-120748
base: a1cffe8cc8aef85f1b07c4464f0998b9785b795a
patch link: https://lore.kernel.org/r/20250321040358.360755-2-18255117159%40163.com
patch subject: [v3 1/4] PCI: Introduce generic capability search functions
config: arc-randconfig-002-20250321 (https://download.01.org/0day-ci/archive/20250321/202503211726.DEvDBGk8-lkp@intel.com/config)
compiler: arc-linux-gcc (GCC) 11.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250321/202503211726.DEvDBGk8-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503211726.DEvDBGk8-lkp@intel.com/
All error/warnings (new ones prefixed by >>):
In file included from drivers/nvme/host/nvme.h:11,
from drivers/nvme/host/fc.c:13:
>> include/linux/pci.h:2021:4: warning: no previous prototype for 'pci_generic_find_capability' [-Wmissing-prototypes]
2021 | u8 pci_generic_find_capability(void *priv, pci_generic_read_cfg read_cfg,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>> include/linux/pci.h:2024:5: warning: no previous prototype for 'pci_generic_find_ext_capability' [-Wmissing-prototypes]
2024 | u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
arc-linux-ld: drivers/scsi/libsas/sas_phy.o: in function `pci_generic_find_capability':
>> sas_phy.c:(.text+0x148): multiple definition of `pci_generic_find_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd18): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_phy.o: in function `pci_generic_find_ext_capability':
>> sas_phy.c:(.text+0x150): multiple definition of `pci_generic_find_ext_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd20): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_port.o: in function `pci_generic_find_capability':
sas_port.c:(.text+0x1c8): multiple definition of `pci_generic_find_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd18): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_port.o: in function `pci_generic_find_ext_capability':
sas_port.c:(.text+0x1d0): multiple definition of `pci_generic_find_ext_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd20): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_event.o: in function `pci_generic_find_capability':
sas_event.c:(.text+0xf8): multiple definition of `pci_generic_find_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd18): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_event.o: in function `pci_generic_find_ext_capability':
sas_event.c:(.text+0x100): multiple definition of `pci_generic_find_ext_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd20): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_discover.o: in function `pci_generic_find_capability':
sas_discover.c:(.text+0x874): multiple definition of `pci_generic_find_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd18): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_discover.o: in function `pci_generic_find_ext_capability':
sas_discover.c:(.text+0x87c): multiple definition of `pci_generic_find_ext_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd20): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_expander.o: in function `pci_generic_find_capability':
sas_expander.c:(.text+0x2378): multiple definition of `pci_generic_find_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd18): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_expander.o: in function `pci_generic_find_ext_capability':
sas_expander.c:(.text+0x2380): multiple definition of `pci_generic_find_ext_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd20): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_scsi_host.o: in function `pci_generic_find_capability':
sas_scsi_host.c:(.text+0x17c0): multiple definition of `pci_generic_find_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd18): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_scsi_host.o: in function `pci_generic_find_ext_capability':
sas_scsi_host.c:(.text+0x17c8): multiple definition of `pci_generic_find_ext_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd20): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_task.o: in function `pci_generic_find_capability':
sas_task.c:(.text+0xd4): multiple definition of `pci_generic_find_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd18): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_task.o: in function `pci_generic_find_ext_capability':
sas_task.c:(.text+0xdc): multiple definition of `pci_generic_find_ext_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd20): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_host_smp.o: in function `pci_generic_find_capability':
sas_host_smp.c:(.text+0x48): multiple definition of `pci_generic_find_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd18): first defined here
arc-linux-ld: drivers/scsi/libsas/sas_host_smp.o: in function `pci_generic_find_ext_capability':
sas_host_smp.c:(.text+0x50): multiple definition of `pci_generic_find_ext_capability'; drivers/scsi/libsas/sas_init.o:sas_init.c:(.text+0xd20): first defined here
--
arc-linux-ld: drivers/pcmcia/cistpl.o: in function `pci_generic_find_capability':
>> cistpl.c:(.text+0xfac): multiple definition of `pci_generic_find_capability'; drivers/pcmcia/pcmcia_resource.o:pcmcia_resource.c:(.text+0x1244): first defined here
arc-linux-ld: drivers/pcmcia/cistpl.o: in function `pci_generic_find_ext_capability':
>> cistpl.c:(.text+0xfb4): multiple definition of `pci_generic_find_ext_capability'; drivers/pcmcia/pcmcia_resource.o:pcmcia_resource.c:(.text+0x124c): first defined here
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [v3 1/4] PCI: Introduce generic capability search functions
2025-03-21 4:03 ` [v3 1/4] PCI: " Hans Zhang
2025-03-21 9:37 ` kernel test robot
@ 2025-03-21 9:37 ` kernel test robot
2025-03-21 9:49 ` kernel test robot
2 siblings, 0 replies; 8+ messages in thread
From: kernel test robot @ 2025-03-21 9:37 UTC (permalink / raw)
To: Hans Zhang, lpieralisi
Cc: llvm, oe-kbuild-all, kw, manivannan.sadhasivam, robh, bhelgaas,
jingoohan1, thomas.richard, linux-pci, linux-kernel, Hans Zhang
Hi Hans,
kernel test robot noticed the following build warnings:
[auto build test WARNING on a1cffe8cc8aef85f1b07c4464f0998b9785b795a]
url: https://github.com/intel-lab-lkp/linux/commits/Hans-Zhang/PCI-Introduce-generic-capability-search-functions/20250321-120748
base: a1cffe8cc8aef85f1b07c4464f0998b9785b795a
patch link: https://lore.kernel.org/r/20250321040358.360755-2-18255117159%40163.com
patch subject: [v3 1/4] PCI: Introduce generic capability search functions
config: arm-randconfig-004-20250321 (https://download.01.org/0day-ci/archive/20250321/202503211730.XKhqW2Mw-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project c2692afc0a92cd5da140dfcdfff7818a5b8ce997)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250321/202503211730.XKhqW2Mw-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503211730.XKhqW2Mw-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from arch/arm/mm/iomap.c:9:
>> include/linux/pci.h:2021:4: warning: no previous prototype for function 'pci_generic_find_capability' [-Wmissing-prototypes]
2021 | u8 pci_generic_find_capability(void *priv, pci_generic_read_cfg read_cfg,
| ^
include/linux/pci.h:2021:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
2021 | u8 pci_generic_find_capability(void *priv, pci_generic_read_cfg read_cfg,
| ^
| static
>> include/linux/pci.h:2024:5: warning: no previous prototype for function 'pci_generic_find_ext_capability' [-Wmissing-prototypes]
2024 | u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
| ^
include/linux/pci.h:2024:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
2024 | u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
| ^
| static
2 warnings generated.
vim +/pci_generic_find_capability +2021 include/linux/pci.h
1999
2000 static inline void pci_set_master(struct pci_dev *dev) { }
2001 static inline void pci_clear_master(struct pci_dev *dev) { }
2002 static inline int pci_enable_device(struct pci_dev *dev) { return -EIO; }
2003 static inline void pci_disable_device(struct pci_dev *dev) { }
2004 static inline int pcim_enable_device(struct pci_dev *pdev) { return -EIO; }
2005 static inline int pci_assign_resource(struct pci_dev *dev, int i)
2006 { return -EBUSY; }
2007 static inline int __must_check __pci_register_driver(struct pci_driver *drv,
2008 struct module *owner,
2009 const char *mod_name)
2010 { return 0; }
2011 static inline int pci_register_driver(struct pci_driver *drv)
2012 { return 0; }
2013 static inline void pci_unregister_driver(struct pci_driver *drv) { }
2014 static inline u8 pci_find_capability(struct pci_dev *dev, int cap)
2015 { return 0; }
2016 static inline u8 pci_find_next_capability(struct pci_dev *dev, u8 post, int cap)
2017 { return 0; }
2018 static inline u16 pci_find_ext_capability(struct pci_dev *dev, int cap)
2019 { return 0; }
2020 typedef u32 (*pci_generic_read_cfg)(void *priv, int where, int size);
> 2021 u8 pci_generic_find_capability(void *priv, pci_generic_read_cfg read_cfg,
2022 u8 cap)
2023 { return 0; }
> 2024 u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
2025 u8 cap)
2026 { return 0; }
2027 static inline u64 pci_get_dsn(struct pci_dev *dev)
2028 { return 0; }
2029
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [v3 1/4] PCI: Introduce generic capability search functions
2025-03-21 4:03 ` [v3 1/4] PCI: " Hans Zhang
2025-03-21 9:37 ` kernel test robot
2025-03-21 9:37 ` kernel test robot
@ 2025-03-21 9:49 ` kernel test robot
2 siblings, 0 replies; 8+ messages in thread
From: kernel test robot @ 2025-03-21 9:49 UTC (permalink / raw)
To: Hans Zhang, lpieralisi
Cc: oe-kbuild-all, kw, manivannan.sadhasivam, robh, bhelgaas,
jingoohan1, thomas.richard, linux-pci, linux-kernel, Hans Zhang
Hi Hans,
kernel test robot noticed the following build errors:
[auto build test ERROR on a1cffe8cc8aef85f1b07c4464f0998b9785b795a]
url: https://github.com/intel-lab-lkp/linux/commits/Hans-Zhang/PCI-Introduce-generic-capability-search-functions/20250321-120748
base: a1cffe8cc8aef85f1b07c4464f0998b9785b795a
patch link: https://lore.kernel.org/r/20250321040358.360755-2-18255117159%40163.com
patch subject: [v3 1/4] PCI: Introduce generic capability search functions
config: arc-randconfig-001-20250321 (https://download.01.org/0day-ci/archive/20250321/202503211714.tv7E2QkK-lkp@intel.com/config)
compiler: arc-linux-gcc (GCC) 13.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250321/202503211714.tv7E2QkK-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503211714.tv7E2QkK-lkp@intel.com/
All errors (new ones prefixed by >>):
>> drivers/pci/pci.c:691:5: error: conflicting types for 'pci_generic_find_ext_capability'; have 'u16(void *, u32 (*)(void *, int, int), int)' {aka 'short unsigned int(void *, unsigned int (*)(void *, int, int), int)'}
691 | u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from drivers/pci/pci.c:18:
include/linux/pci.h:1211:5: note: previous declaration of 'pci_generic_find_ext_capability' with type 'u16(void *, u32 (*)(void *, int, int), u8)' {aka 'short unsigned int(void *, unsigned int (*)(void *, int, int), unsigned char)'}
1211 | u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from include/linux/linkage.h:7,
from include/linux/preempt.h:10,
from include/linux/spinlock.h:56,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:7,
from include/linux/slab.h:16,
from include/linux/resource_ext.h:11,
from include/linux/acpi.h:13,
from drivers/pci/pci.c:11:
drivers/pci/pci.c:696:19: error: conflicting types for 'pci_generic_find_ext_capability'; have 'u16(void *, u32 (*)(void *, int, int), int)' {aka 'short unsigned int(void *, unsigned int (*)(void *, int, int), int)'}
696 | EXPORT_SYMBOL_GPL(pci_generic_find_ext_capability);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/export.h:70:28: note: in definition of macro '__EXPORT_SYMBOL'
70 | extern typeof(sym) sym; \
| ^~~
include/linux/export.h:84:41: note: in expansion of macro '_EXPORT_SYMBOL'
84 | #define EXPORT_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "GPL")
| ^~~~~~~~~~~~~~
drivers/pci/pci.c:696:1: note: in expansion of macro 'EXPORT_SYMBOL_GPL'
696 | EXPORT_SYMBOL_GPL(pci_generic_find_ext_capability);
| ^~~~~~~~~~~~~~~~~
include/linux/pci.h:1211:5: note: previous declaration of 'pci_generic_find_ext_capability' with type 'u16(void *, u32 (*)(void *, int, int), u8)' {aka 'short unsigned int(void *, unsigned int (*)(void *, int, int), unsigned char)'}
1211 | u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +691 drivers/pci/pci.c
690
> 691 u16 pci_generic_find_ext_capability(void *priv, pci_generic_read_cfg read_cfg,
692 int cap)
693 {
694 return pci_generic_find_next_ext_capability(priv, read_cfg, 0, cap);
695 }
696 EXPORT_SYMBOL_GPL(pci_generic_find_ext_capability);
697
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 8+ messages in thread
* [v3 2/4] PCI: dwc: Replace dw_pcie_find_capability() and dw_pcie_find_ext_capability()
2025-03-21 4:03 [v3 0/4] Introduce generic capability search functions Hans Zhang
2025-03-21 4:03 ` [v3 1/4] PCI: " Hans Zhang
@ 2025-03-21 4:03 ` Hans Zhang
2025-03-21 4:03 ` [v3 3/4] PCI: cadence: Add configuration space capability search API Hans Zhang
2025-03-21 4:03 ` [v3 4/4] PCI: cadence: Use cdns_pcie_find_*capability to find capability offset instead of hardcore Hans Zhang
3 siblings, 0 replies; 8+ messages in thread
From: Hans Zhang @ 2025-03-21 4:03 UTC (permalink / raw)
To: lpieralisi
Cc: kw, manivannan.sadhasivam, robh, bhelgaas, jingoohan1,
thomas.richard, linux-pci, linux-kernel, Hans Zhang
Replace duplicate logic code. Use a common interface and provide callback
functions.
Signed-off-by: Hans Zhang <18255117159@163.com>
---
drivers/pci/controller/dwc/pcie-designware.c | 71 ++------------------
1 file changed, 5 insertions(+), 66 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 145e7f579072..2ebebedbf18d 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -203,83 +203,22 @@ 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)
+static u32 dwc_pcie_read_cfg(void *priv, int where, int size)
{
- 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;
+ struct dw_pcie *pci = priv;
- if (cap_id == cap)
- return cap_ptr;
-
- next_cap_ptr = (reg & 0xff00) >> 8;
- return __dw_pcie_find_next_cap(pci, next_cap_ptr, cap);
+ return dw_pcie_read_dbi(pci, where, size);
}
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_generic_find_capability(pci, dwc_pcie_read_cfg, cap);
}
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_generic_find_ext_capability(pci, dwc_pcie_read_cfg, cap);
}
EXPORT_SYMBOL_GPL(dw_pcie_find_ext_capability);
--
2.25.1
^ permalink raw reply [flat|nested] 8+ messages in thread* [v3 3/4] PCI: cadence: Add configuration space capability search API
2025-03-21 4:03 [v3 0/4] Introduce generic capability search functions Hans Zhang
2025-03-21 4:03 ` [v3 1/4] PCI: " Hans Zhang
2025-03-21 4:03 ` [v3 2/4] PCI: dwc: Replace dw_pcie_find_capability() and dw_pcie_find_ext_capability() Hans Zhang
@ 2025-03-21 4:03 ` Hans Zhang
2025-03-21 4:03 ` [v3 4/4] PCI: cadence: Use cdns_pcie_find_*capability to find capability offset instead of hardcore Hans Zhang
3 siblings, 0 replies; 8+ messages in thread
From: Hans Zhang @ 2025-03-21 4:03 UTC (permalink / raw)
To: lpieralisi
Cc: kw, manivannan.sadhasivam, robh, bhelgaas, jingoohan1,
thomas.richard, linux-pci, linux-kernel, Hans Zhang
Add configuration space capability search API using struct cdns_pcie*
pointer.
Signed-off-by: Hans Zhang <18255117159@163.com>
---
drivers/pci/controller/cadence/pcie-cadence.c | 25 +++++++++++++++++++
drivers/pci/controller/cadence/pcie-cadence.h | 3 +++
2 files changed, 28 insertions(+)
diff --git a/drivers/pci/controller/cadence/pcie-cadence.c b/drivers/pci/controller/cadence/pcie-cadence.c
index 204e045aed8c..ea9bfbe76cd6 100644
--- a/drivers/pci/controller/cadence/pcie-cadence.c
+++ b/drivers/pci/controller/cadence/pcie-cadence.c
@@ -8,6 +8,31 @@
#include "pcie-cadence.h"
+static u32 cdns_pcie_read_cfg(void *priv, int where, int size)
+{
+ struct cdns_pcie *pcie = priv;
+ u32 val;
+
+ if (size == 4)
+ val = readl(pcie->reg_base + where);
+ else if (size == 2)
+ val = readw(pcie->reg_base + where);
+ else if (size == 1)
+ val = readb(pcie->reg_base + where);
+
+ return val;
+}
+
+u8 cdns_pcie_find_capability(struct cdns_pcie *pcie, u8 cap)
+{
+ return pci_generic_find_capability(pcie, cdns_pcie_read_cfg, cap);
+}
+
+u16 cdns_pcie_find_ext_capability(struct cdns_pcie *pcie, u8 cap)
+{
+ return pci_generic_find_ext_capability(pcie, cdns_pcie_read_cfg, cap);
+}
+
void cdns_pcie_detect_quiet_min_delay_set(struct cdns_pcie *pcie)
{
u32 delay = 0x3;
diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
index f5eeff834ec1..6f4981fccb94 100644
--- a/drivers/pci/controller/cadence/pcie-cadence.h
+++ b/drivers/pci/controller/cadence/pcie-cadence.h
@@ -557,6 +557,9 @@ static inline int cdns_pcie_ep_setup(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,
--
2.25.1
^ permalink raw reply [flat|nested] 8+ messages in thread* [v3 4/4] PCI: cadence: Use cdns_pcie_find_*capability to find capability offset instead of hardcore
2025-03-21 4:03 [v3 0/4] Introduce generic capability search functions Hans Zhang
` (2 preceding siblings ...)
2025-03-21 4:03 ` [v3 3/4] PCI: cadence: Add configuration space capability search API Hans Zhang
@ 2025-03-21 4:03 ` Hans Zhang
3 siblings, 0 replies; 8+ messages in thread
From: Hans Zhang @ 2025-03-21 4:03 UTC (permalink / raw)
To: lpieralisi
Cc: kw, manivannan.sadhasivam, robh, bhelgaas, jingoohan1,
thomas.richard, linux-pci, linux-kernel, Hans Zhang
The offset address of capability or extended capability designed by
different SOC design companies may not be the same. Therefore, a flexible
public API is required to find the offset address of a capability or
extended capability in the configuration space.
Signed-off-by: Hans Zhang <18255117159@163.com>
---
.../pci/controller/cadence/pcie-cadence-ep.c | 40 +++++++++++--------
drivers/pci/controller/cadence/pcie-cadence.h | 5 ---
2 files changed, 23 insertions(+), 22 deletions(-)
diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
index e0cc4560dfde..aea53ddcaf9b 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
@@ -19,12 +19,13 @@
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);
@@ -36,10 +37,11 @@ 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;
@@ -224,9 +226,10 @@ static int cdns_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 vfn, u8 mmc)
{
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;
+ u8 cap;
+ cap = cdns_pcie_find_capability(pcie, PCI_CAP_ID_MSI);
fn = cdns_pcie_get_fn_from_vfn(pcie, fn, vfn);
/*
@@ -246,9 +249,10 @@ 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_MSI);
fn = cdns_pcie_get_fn_from_vfn(pcie, fn, vfn);
/* Validate that the MSI feature is actually enabled. */
@@ -269,9 +273,10 @@ 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;
@@ -290,9 +295,10 @@ 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;
@@ -379,11 +385,11 @@ 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. */
@@ -431,14 +437,14 @@ 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. */
@@ -481,16 +487,16 @@ 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];
@@ -564,7 +570,9 @@ 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.
@@ -588,12 +596,10 @@ 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);
+ cdns_pcie_ep_fn_writel(pcie, epf, cap + PCI_EXP_DEVCAP,
+ value);
}
}
diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
index 6f4981fccb94..d0fcf1b3549c 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
*/
--
2.25.1
^ permalink raw reply [flat|nested] 8+ messages in thread