From 1e11b5494c3dbb1e5fce7e95021c1698799c7288 Mon Sep 17 00:00:00 2001 From: "David E. Box" Date: Fri, 23 Feb 2024 14:58:49 -0600 Subject: PCI/ASPM: Move pci_save_ltr_state() to aspm.c Even when CONFIG_PCIEASPM is not set, we save and restore the LTR Capability so that if ASPM L1.2 and LTR were configured by the platform, ASPM L1.2 will still work after suspend/resume, when that platform configuration may be lost. See dbbfadf23190 ("PCI/ASPM: Save LTR Capability for suspend/resume"). Since ASPM L1.2 depends on the LTR Capability, move the save/restore code to the part of aspm.c that is always compiled regardless of CONFIG_PCIEASPM. No functional change intended. Suggested-by: Bjorn Helgaas Link: https://lore.kernel.org/r/20240128233212.1139663-5-david.e.box@linux.intel.com [bhelgaas: commit log, reorder to make this a pure move] Link: https://lore.kernel.org/r/20240223205851.114931-4-helgaas@kernel.org Signed-off-by: David E. Box Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 40 ---------------------------------------- drivers/pci/pci.h | 5 +++++ drivers/pci/pcie/aspm.c | 40 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 45 insertions(+), 40 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index c783e0f1f2a9..564e2cf2dde5 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1689,46 +1689,6 @@ static void pci_restore_pcix_state(struct pci_dev *dev) pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]); } -static void pci_save_ltr_state(struct pci_dev *dev) -{ - int ltr; - struct pci_cap_saved_state *save_state; - u32 *cap; - - if (!pci_is_pcie(dev)) - return; - - ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); - if (!ltr) - return; - - save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); - if (!save_state) { - pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n"); - return; - } - - /* Some broken devices only support dword access to LTR */ - cap = &save_state->cap.data[0]; - pci_read_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap); -} - -static void pci_restore_ltr_state(struct pci_dev *dev) -{ - struct pci_cap_saved_state *save_state; - int ltr; - u32 *cap; - - save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); - ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); - if (!save_state || !ltr) - return; - - /* Some broken devices only support dword access to LTR */ - cap = &save_state->cap.data[0]; - pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap); -} - /** * pci_save_state - save the PCI configuration space of a device before * suspending diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 9aeba82facc4..ad3add45345c 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -567,6 +567,11 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, bool pcie_wait_for_link(struct pci_dev *pdev, bool active); int pcie_retrain_link(struct pci_dev *pdev, bool use_lt); + +/* ASPM-related functionality we need even without CONFIG_PCIEASPM */ +void pci_save_ltr_state(struct pci_dev *dev); +void pci_restore_ltr_state(struct pci_dev *dev); + #ifdef CONFIG_PCIEASPM void pcie_aspm_init_link_state(struct pci_dev *pdev); void pcie_aspm_exit_link_state(struct pci_dev *pdev); diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index d50c0f83430f..21731b232fb8 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -24,6 +24,46 @@ #include "../pci.h" +void pci_save_ltr_state(struct pci_dev *dev) +{ + int ltr; + struct pci_cap_saved_state *save_state; + u32 *cap; + + if (!pci_is_pcie(dev)) + return; + + ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); + if (!ltr) + return; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); + if (!save_state) { + pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n"); + return; + } + + /* Some broken devices only support dword access to LTR */ + cap = &save_state->cap.data[0]; + pci_read_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap); +} + +void pci_restore_ltr_state(struct pci_dev *dev) +{ + struct pci_cap_saved_state *save_state; + int ltr; + u32 *cap; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); + ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); + if (!save_state || !ltr) + return; + + /* Some broken devices only support dword access to LTR */ + cap = &save_state->cap.data[0]; + pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap); +} + #ifdef CONFIG_PCIEASPM #ifdef MODULE_PARAM_PREFIX -- cgit