diff options
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index fd47ac0c473..1bb879959a2 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1375,6 +1375,166 @@ pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask) #endif /** + * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count + * @dev: PCI device to query + * + * Returns mmrbc: maximum designed memory read count in bytes + * or appropriate error value. + */ +int pcix_get_max_mmrbc(struct pci_dev *dev) +{ + int ret, err, cap; + u32 stat; + + cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); + if (!cap) + return -EINVAL; + + err = pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat); + if (err) + return -EINVAL; + + ret = (stat & PCI_X_STATUS_MAX_READ) >> 12; + + return ret; +} +EXPORT_SYMBOL(pcix_get_max_mmrbc); + +/** + * pcix_get_mmrbc - get PCI-X maximum memory read byte count + * @dev: PCI device to query + * + * Returns mmrbc: maximum memory read count in bytes + * or appropriate error value. + */ +int pcix_get_mmrbc(struct pci_dev *dev) +{ + int ret, cap; + u32 cmd; + + cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); + if (!cap) + return -EINVAL; + + ret = pci_read_config_dword(dev, cap + PCI_X_CMD, &cmd); + if (!ret) + ret = 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2); + + return ret; +} +EXPORT_SYMBOL(pcix_get_mmrbc); + +/** + * pcix_set_mmrbc - set PCI-X maximum memory read byte count + * @dev: PCI device to query + * @mmrbc: maximum memory read count in bytes + * valid values are 512, 1024, 2048, 4096 + * + * If possible sets maximum memory read byte count, some bridges have erratas + * that prevent this. + */ +int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc) +{ + int cap, err = -EINVAL; + u32 stat, cmd, v, o; + + if (mmrbc < 512 || mmrbc > 4096 || (mmrbc & (mmrbc-1))) + goto out; + + v = ffs(mmrbc) - 10; + + cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); + if (!cap) + goto out; + + err = pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat); + if (err) + goto out; + + if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21) + return -E2BIG; + + err = pci_read_config_dword(dev, cap + PCI_X_CMD, &cmd); + if (err) + goto out; + + o = (cmd & PCI_X_CMD_MAX_READ) >> 2; + if (o != v) { + if (v > o && dev->bus && + (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC)) + return -EIO; + + cmd &= ~PCI_X_CMD_MAX_READ; + cmd |= v << 2; + err = pci_write_config_dword(dev, cap + PCI_X_CMD, cmd); + } +out: + return err; +} +EXPORT_SYMBOL(pcix_set_mmrbc); + +/** + * pcie_get_readrq - get PCI Express read request size + * @dev: PCI device to query + * + * Returns maximum memory read request in bytes + * or appropriate error value. + */ +int pcie_get_readrq(struct pci_dev *dev) +{ + int ret, cap; + u16 ctl; + + cap = pci_find_capability(dev, PCI_CAP_ID_EXP); + if (!cap) + return -EINVAL; + + ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl); + if (!ret) + ret = 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12); + + return ret; +} +EXPORT_SYMBOL(pcie_get_readrq); + +/** + * pcie_set_readrq - set PCI Express maximum memory read request + * @dev: PCI device to query + * @count: maximum memory read count in bytes + * valid values are 128, 256, 512, 1024, 2048, 4096 + * + * If possible sets maximum read byte count + */ +int pcie_set_readrq(struct pci_dev *dev, int rq) +{ + int cap, err = -EINVAL; + u16 ctl, v; + + if (rq < 128 || rq > 4096 || (rq & (rq-1))) + goto out; + + v = (ffs(rq) - 8) << 12; + + cap = pci_find_capability(dev, PCI_CAP_ID_EXP); + if (!cap) + goto out; + + err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl); + if (err) + goto out; + + if ((ctl & PCI_EXP_DEVCTL_READRQ) != v) { + ctl &= ~PCI_EXP_DEVCTL_READRQ; + ctl |= v; + err = pci_write_config_dword(dev, cap + PCI_EXP_DEVCTL, ctl); + } + +out: + return err; +} +EXPORT_SYMBOL(pcie_set_readrq); + +/** * pci_select_bars - Make BAR mask from the type of resource * @dev: the PCI device for which BAR mask is made * @flags: resource type mask to be selected |