PCI/ASPM: Factor out pcie_wait_for_retrain()

[ 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>

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index e7f742ff31c3c714ca19a29c9cc56b456280a357..5e09cbb56336622bc570e9212515a6ee26aa0a60 100644 (file)
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -192,10 +192,26 @@ 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);
@@ -211,17 +227,7 @@ 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);
 }
 
 /*