LTR: Save Max snoop/no-snoop Latency Value in pci_save_pcie_state, and restore them in pci_restore_pcie_state.
Signed-off-by: Xudong Hao <[email protected]> --- drivers/pci/pci.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++--- drivers/pci/probe.c | 5 +++- 2 files changed, 71 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 35127c1..7172f15 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -912,6 +912,54 @@ static void pci_restore_pcie_state(struct pci_dev *dev) pci_write_config_word(dev, pos + PCI_EXP_SLTCTL2, cap[i++]); } +#define PCI_LTR_SAVE_REGS 2 + +static int pci_save_ltr_value(struct pci_dev *dev) +{ + int i = 0, pos; + struct pci_cap_saved_state *save_state; + u16 *cap; + u16 ctrl; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); + if (!pos) + return -ENOTSUPP; + + /* Check if LTR is eanbled before save value */ + pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl); + if (!(ctrl & PCI_EXP_LTR_EN)) + return -ENOTSUPP; + + save_state = pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR); + if (!save_state) { + dev_err(&dev->dev, "buffer not found in %s\n", __func__); + return -ENOMEM; + } + cap = (u16 *)&save_state->cap.data[0]; + + pci_read_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, &cap[i++]); + pci_read_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, &cap[i++]); + return 0; +} + +static void pci_restore_ltr_value(struct pci_dev *dev) +{ + int i = 0, pos; + struct pci_cap_saved_state *save_state; + u16 *cap; + + if (!pci_ltr_supported(dev)) + return; + + save_state = pci_find_saved_cap(dev, PCI_EXT_CAP_ID_LTR); + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); + if (!save_state || !pos) + return; + cap = (u16 *)&save_state->cap.data[0]; + + pci_write_config_word(dev, pos + PCI_LTR_MAX_SNOOP_LAT, cap[i++]); + pci_write_config_word(dev, pos + PCI_LTR_MAX_NOSNOOP_LAT, cap[i++]); +} static int pci_save_pcix_state(struct pci_dev *dev) { @@ -966,6 +1014,11 @@ pci_save_state(struct pci_dev *dev) return i; if ((i = pci_save_pcix_state(dev)) != 0) return i; + + if (pci_ltr_supported(dev)) + if ((i = pci_save_ltr_value(dev)) != 0) + return i; + return 0; } @@ -1034,6 +1087,7 @@ void pci_restore_state(struct pci_dev *dev) pci_restore_pcix_state(dev); pci_restore_msi_state(dev); pci_restore_iov_state(dev); + pci_restore_ltr_value(dev); dev->state_saved = false; } @@ -1955,12 +2009,15 @@ static void pci_add_saved_cap(struct pci_dev *pci_dev, * @size: requested size of the buffer */ static int pci_add_cap_save_buffer( - struct pci_dev *dev, char cap, unsigned int size) + struct pci_dev *dev, char cap, unsigned int size, bool is_extcap) { int pos; struct pci_cap_saved_state *save_state; - pos = pci_find_capability(dev, cap); + if (is_extcap) + pos = pci_find_ext_capability(dev, cap); + else + pos = pci_find_capability(dev, cap); if (pos <= 0) return 0; @@ -1984,15 +2041,21 @@ void pci_allocate_cap_save_buffers(struct pci_dev *dev) int error; error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP, - PCI_EXP_SAVE_REGS * sizeof(u16)); + PCI_EXP_SAVE_REGS * sizeof(u16), 0); if (error) dev_err(&dev->dev, "unable to preallocate PCI Express save buffer\n"); - error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16)); + error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16), 0); if (error) dev_err(&dev->dev, "unable to preallocate PCI-X save buffer\n"); + + error = pci_add_cap_save_buffer(dev, PCI_EXT_CAP_ID_LTR, + PCI_LTR_SAVE_REGS * sizeof(u16), 1); + if (error) + dev_err(&dev->dev, + "unable to preallocate LTR save buffer\n"); } void pci_free_cap_save_buffers(struct pci_dev *dev) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 658ac97..a6eb509 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1232,7 +1232,10 @@ static void pci_init_capabilities(struct pci_dev *dev) /* MSI/MSI-X list */ pci_msi_init_pci_dev(dev); - /* Buffers for saving PCIe and PCI-X capabilities */ + /* + * Buffers for saving PCIe and PCI-X capabilities + * and for saving LTR extented capabilities. + */ pci_allocate_cap_save_buffers(dev); /* Power Management */ -- 1.5.5 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
