[PATCH 6.6 250/568] PCI: keystone: Dont enable BAR 0 for AM654x

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6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Siddharth Vadapalli <s-vadapalli@xxxxxx>

[ Upstream commit 9ffa0e70b2daf9b0271e4960b7c8a2350e2cda08 ]

After 6ab15b5e7057 ("PCI: dwc: keystone: Convert .scan_bus() callback to
use add_bus"), ks_pcie_v3_65_add_bus() enabled BAR 0 for both v3.65a and
v4.90a devices.  On the AM654x SoC, which uses v4.90a, enabling BAR 0
causes Completion Timeouts when setting up MSI-X.  These timeouts delay
boot of the AM654x by about 45 seconds.

Move the BAR 0 initialization to ks_pcie_msi_host_init(), which is only
used for v3.65a devices, and remove ks_pcie_v3_65_add_bus().

[bhelgaas: commit log]
Fixes: 6ab15b5e7057 ("PCI: dwc: keystone: Convert .scan_bus() callback to use add_bus")
Link: https://lore.kernel.org/linux-pci/20240328085041.2916899-3-s-vadapalli@xxxxxx
Suggested-by: Bjorn Helgaas <helgaas@xxxxxxxxxx>
Suggested-by: Niklas Cassel <cassel@xxxxxxxxxx>
Suggested-by: Serge Semin <fancer.lancer@xxxxxxxxx>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@xxxxxx>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Niklas Cassel <cassel@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/pci/controller/dwc/pci-keystone.c | 52 ++++++++---------------
 1 file changed, 18 insertions(+), 34 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index bf907c8ca25bb..9886fdd415039 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -290,6 +290,24 @@ static void ks_pcie_clear_dbi_mode(struct keystone_pcie *ks_pcie)
 
 static int ks_pcie_msi_host_init(struct dw_pcie_rp *pp)
 {
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct keystone_pcie *ks_pcie = to_keystone_pcie(pci);
+
+	/* Configure and set up BAR0 */
+	ks_pcie_set_dbi_mode(ks_pcie);
+
+	/* Enable BAR0 */
+	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 1);
+	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, SZ_4K - 1);
+
+	ks_pcie_clear_dbi_mode(ks_pcie);
+
+	/*
+	 * For BAR0, just setting bus address for inbound writes (MSI) should
+	 * be sufficient.  Use physical address to avoid any conflicts.
+	 */
+	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, ks_pcie->app.start);
+
 	pp->msi_irq_chip = &ks_pcie_msi_irq_chip;
 	return dw_pcie_allocate_domains(pp);
 }
@@ -447,44 +465,10 @@ static struct pci_ops ks_child_pcie_ops = {
 	.write = pci_generic_config_write,
 };
 
-/**
- * ks_pcie_v3_65_add_bus() - keystone add_bus post initialization
- * @bus: A pointer to the PCI bus structure.
- *
- * This sets BAR0 to enable inbound access for MSI_IRQ register
- */
-static int ks_pcie_v3_65_add_bus(struct pci_bus *bus)
-{
-	struct dw_pcie_rp *pp = bus->sysdata;
-	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
-	struct keystone_pcie *ks_pcie = to_keystone_pcie(pci);
-
-	if (!pci_is_root_bus(bus))
-		return 0;
-
-	/* Configure and set up BAR0 */
-	ks_pcie_set_dbi_mode(ks_pcie);
-
-	/* Enable BAR0 */
-	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 1);
-	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, SZ_4K - 1);
-
-	ks_pcie_clear_dbi_mode(ks_pcie);
-
-	 /*
-	  * For BAR0, just setting bus address for inbound writes (MSI) should
-	  * be sufficient.  Use physical address to avoid any conflicts.
-	  */
-	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, ks_pcie->app.start);
-
-	return 0;
-}
-
 static struct pci_ops ks_pcie_ops = {
 	.map_bus = dw_pcie_own_conf_map_bus,
 	.read = pci_generic_config_read,
 	.write = pci_generic_config_write,
-	.add_bus = ks_pcie_v3_65_add_bus,
 };
 
 /**
-- 
2.43.0







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