On Friday 05 November 2021 22:09:47 Pali Rohár wrote: > On Friday 05 November 2021 12:54:24 Roman Bacik wrote: > > > > + pci_read_word16(bp->pdev, > > > > + PCI_SUBSYSTEM_VENDOR_ID, > > > > + &bp->subsystem_vendor); > > > > + pci_read_word16(bp->pdev, PCI_SUBSYSTEM_ID, &bp- > > > >subsystem_device); > > > > + pci_read_word16(bp->pdev, PCI_COMMAND, &bp->cmd_reg); > > > > + pci_read_byte(bp->pdev, PCICFG_ME_REGISTER, &bp->pf_num); > > > > > > PCICFG_ME_REGISTER looks like an error as there is no such PCI config > > > space macro. What you are trying to read into pf_num? Currently I do not > > > know what "pf" abbreviation could mean. > > > > PF stands for physical function and pf_num is the number of physical > > functions configured. > > The macro is defined in bnxt.h: > > #define PCICFG_ME_REGISTER 0x98 > > pci_read_byte() reads from PCI(e) config space, which is standardized. > Therefore only standard macro constants from include/pci.h should be > used. Standard PCI config header is 64 byte long and after that is > linked list of capabilities. Order of capabilities is not defined. > Extended capabilities from linked list should be located by macro > constants PCI_CAP_ID_*. > > So above register is part of some extended capability. Correctly it > should be used some function to locate starting offset of that extended > capability based on PCI_CAP_ID_* (see pci.h file for these functions) > and then access that register as offset + PCI_* constant (which defined > as relative to the start of extended capability). In case standard macro > for this constant in pci.h is missing, it is a good idea to define it, > or copy it from linux header file pci_regs.h (to have consistent naming > of macros).
Just one example how to read PCIe Link Control Register (to make it clear what I mean): int ret; u16 lnkctl; int pci_exp_off; pci_exp_off = dm_pci_find_capability(dev, PCI_CAP_ID_EXP); if (!pci_exp_off) return -ENOENT; ret = dm_pci_read_config16(dev, pci_exp_off + PCI_EXP_LNKCTL, &lnkctl); if (ret) return ret;
