PCI/ASPM: Factor out L1 PM Substates configuration

Move L1 PM Substates configuration from pcie_aspm_cap_init() to a new
aspm_l1ss_init() function.  No functional change intended.

Link: https://lore.kernel.org/r/20221005025809.2247547-2-helgaas@kernel.orgSigned-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

drivers/pci/pcie/aspm.c

@@ -554,13 +554,65 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link,
 	aspm_program_l1ss(child, cctl1, ctl2);
 }
 
+static void aspm_l1ss_init(struct pcie_link_state *link)
+{
+	struct pci_dev *child = link->downstream, *parent = link->pdev;
+	u32 parent_l1ss_cap, child_l1ss_cap;
+	u32 parent_l1ss_ctl1 = 0, child_l1ss_ctl1 = 0;
+
+	/* Setup L1 substate */
+	pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CAP,
+			      &parent_l1ss_cap);
+	pci_read_config_dword(child, child->l1ss + PCI_L1SS_CAP,
+			      &child_l1ss_cap);
+
+	if (!(parent_l1ss_cap & PCI_L1SS_CAP_L1_PM_SS))
+		parent_l1ss_cap = 0;
+	if (!(child_l1ss_cap & PCI_L1SS_CAP_L1_PM_SS))
+		child_l1ss_cap = 0;
+
+	/*
+	 * If we don't have LTR for the entire path from the Root Complex
+	 * to this device, we can't use ASPM L1.2 because it relies on the
+	 * LTR_L1.2_THRESHOLD.  See PCIe r4.0, secs 5.5.4, 6.18.
+	 */
+	if (!child->ltr_path)
+		child_l1ss_cap &= ~PCI_L1SS_CAP_ASPM_L1_2;
+
+	if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_ASPM_L1_1)
+		link->aspm_support |= ASPM_STATE_L1_1;
+	if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_ASPM_L1_2)
+		link->aspm_support |= ASPM_STATE_L1_2;
+	if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_PCIPM_L1_1)
+		link->aspm_support |= ASPM_STATE_L1_1_PCIPM;
+	if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_PCIPM_L1_2)
+		link->aspm_support |= ASPM_STATE_L1_2_PCIPM;
+
+	if (parent_l1ss_cap)
+		pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
+				      &parent_l1ss_ctl1);
+	if (child_l1ss_cap)
+		pci_read_config_dword(child, child->l1ss + PCI_L1SS_CTL1,
+				      &child_l1ss_ctl1);
+
+	if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_1)
+		link->aspm_enabled |= ASPM_STATE_L1_1;
+	if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_2)
+		link->aspm_enabled |= ASPM_STATE_L1_2;
+	if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_1)
+		link->aspm_enabled |= ASPM_STATE_L1_1_PCIPM;
+	if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_2)
+		link->aspm_enabled |= ASPM_STATE_L1_2_PCIPM;
+
+	if (link->aspm_support & ASPM_STATE_L1SS)
+		aspm_calc_l1ss_info(link, parent_l1ss_cap, child_l1ss_cap);
+}
+
 static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
 {
 	struct pci_dev *child = link->downstream, *parent = link->pdev;
 	u32 parent_lnkcap, child_lnkcap;
 	u16 parent_lnkctl, child_lnkctl;
-	u32 parent_l1ss_cap, child_l1ss_cap;
-	u32 parent_l1ss_ctl1 = 0, child_l1ss_ctl1 = 0;
 	struct pci_bus *linkbus = parent->subordinate;
 
 	if (blacklist) {
@@ -615,52 +667,7 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist)
 	if (parent_lnkctl & child_lnkctl & PCI_EXP_LNKCTL_ASPM_L1)
 		link->aspm_enabled |= ASPM_STATE_L1;
 
-	/* Setup L1 substate */
-	pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CAP,
-			      &parent_l1ss_cap);
-	pci_read_config_dword(child, child->l1ss + PCI_L1SS_CAP,
-			      &child_l1ss_cap);
-
-	if (!(parent_l1ss_cap & PCI_L1SS_CAP_L1_PM_SS))
-		parent_l1ss_cap = 0;
-	if (!(child_l1ss_cap & PCI_L1SS_CAP_L1_PM_SS))
-		child_l1ss_cap = 0;
-
-	/*
-	 * If we don't have LTR for the entire path from the Root Complex
-	 * to this device, we can't use ASPM L1.2 because it relies on the
-	 * LTR_L1.2_THRESHOLD.  See PCIe r4.0, secs 5.5.4, 6.18.
-	 */
-	if (!child->ltr_path)
-		child_l1ss_cap &= ~PCI_L1SS_CAP_ASPM_L1_2;
-
-	if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_ASPM_L1_1)
-		link->aspm_support |= ASPM_STATE_L1_1;
-	if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_ASPM_L1_2)
-		link->aspm_support |= ASPM_STATE_L1_2;
-	if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_PCIPM_L1_1)
-		link->aspm_support |= ASPM_STATE_L1_1_PCIPM;
-	if (parent_l1ss_cap & child_l1ss_cap & PCI_L1SS_CAP_PCIPM_L1_2)
-		link->aspm_support |= ASPM_STATE_L1_2_PCIPM;
-
-	if (parent_l1ss_cap)
-		pci_read_config_dword(parent, parent->l1ss + PCI_L1SS_CTL1,
-				      &parent_l1ss_ctl1);
-	if (child_l1ss_cap)
-		pci_read_config_dword(child, child->l1ss + PCI_L1SS_CTL1,
-				      &child_l1ss_ctl1);
-
-	if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_1)
-		link->aspm_enabled |= ASPM_STATE_L1_1;
-	if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_ASPM_L1_2)
-		link->aspm_enabled |= ASPM_STATE_L1_2;
-	if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_1)
-		link->aspm_enabled |= ASPM_STATE_L1_1_PCIPM;
-	if (parent_l1ss_ctl1 & child_l1ss_ctl1 & PCI_L1SS_CTL1_PCIPM_L1_2)
-		link->aspm_enabled |= ASPM_STATE_L1_2_PCIPM;
-
-	if (link->aspm_support & ASPM_STATE_L1SS)
-		aspm_calc_l1ss_info(link, parent_l1ss_cap, child_l1ss_cap);
+	aspm_l1ss_init(link);
 
 	/* Save default state */
 	link->aspm_default = link->aspm_enabled;