[PATCH 4.19 226/323] PCI/ASPM: Factor out pcie_wait_for_retrain()

From: Ilpo Järvinen ilpo.jarvinen@linux.intel.com

[ Upstream commit 9c7f136433d26592cb4d9cd00b4e15c33d9797c6 ]

Factor pcie_wait_for_retrain() out from pcie_retrain_link(). No functional change intended.

[bhelgaas: split out from https: //lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com] Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Stable-dep-of: e7e39756363a ("PCI/ASPM: Avoid link retraining race") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/pcie/aspm.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 86bf1356cfa3f..7b1fb6cb16fba 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -203,10 +203,26 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist) link->clkpm_disable = blacklist ? 1 : 0; }

+static int pcie_wait_for_retrain(struct pci_dev *pdev) +{ + unsigned long end_jiffies; + u16 reg16; + + /* Wait for Link Training to be cleared by hardware */ + end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT; + do { + pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &reg16); + if (!(reg16 & PCI_EXP_LNKSTA_LT)) + return 0; + msleep(1); + } while (time_before(jiffies, end_jiffies)); + + return -ETIMEDOUT; +} + static int pcie_retrain_link(struct pcie_link_state *link) { struct pci_dev *parent = link->pdev; - unsigned long end_jiffies; u16 reg16;

pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &reg16); @@ -222,17 +238,7 @@ static int pcie_retrain_link(struct pcie_link_state *link) pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16); }

- /* Wait for link training end. Break out after waiting for timeout */ - end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT; - do { - pcie_capability_read_word(parent, PCI_EXP_LNKSTA, &reg16); - if (!(reg16 & PCI_EXP_LNKSTA_LT)) - break; - msleep(1); - } while (time_before(jiffies, end_jiffies)); - if (reg16 & PCI_EXP_LNKSTA_LT) - return -ETIMEDOUT; - return 0; + return pcie_wait_for_retrain(parent); }

/*