[PATCH 4/5] PCI: Move pci_save/restore_ltr_state() to aspm.c

From: David E. Box
Date: Sun Jan 28 2024 - 18:32:55 EST


Since the LTR Capability is linked with ASPM and only enabled when
CONFIG_PCIEASPM is set, move the save/restore code to aspm.c

Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
---
drivers/pci/pci.c | 40 ----------------------------------------
drivers/pci/pci.h | 2 ++
drivers/pci/pcie/aspm.c | 40 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 42 insertions(+), 40 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 0a8613e77dab..61e56e040510 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1636,46 +1636,6 @@ 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 7b14cdbe2e69..98f54b48f013 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -100,6 +100,8 @@ void pci_bridge_d3_update(struct pci_dev *dev);
void pci_aspm_get_l1ss(struct pci_dev *pdev);
void pci_save_aspm_state(struct pci_dev *pdev);
void pci_restore_aspm_state(struct pci_dev *pdev);
+void pci_save_ltr_state(struct pci_dev *dev);
+void pci_restore_ltr_state(struct pci_dev *dev);
int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type);

static inline void pci_wakeup_event(struct pci_dev *dev)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 3185058e9c41..f7712d8453a4 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -155,6 +155,46 @@ void pci_restore_aspm_state(struct pci_dev *pdev)
pcie_capability_set_word(pdev, PCI_EXP_LNKCTL, val);
}

+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
--
2.34.1