[PATCH v3 07/12] PCI: rockchip-ep: Refactor rockchip_pcie_ep_probe() MSI-X hiding

Damien Le Moal
2024-10-07T04:12:37Z

Move the code in rockchip_pcie_ep_probe() to hide the MSI-X capability
to its own function, rockchip_pcie_ep_hide_msix_cap(). No functional
changes.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
---
drivers/pci/controller/pcie-rockchip-ep.c | 54 +++++++++++++----------
1 file changed, 30 insertions(+), 24 deletions(-)

diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index 523e9cdfd241..7a1798fcc2ad 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -581,6 +581,34 @@ static void rockchip_pcie_ep_release_resources(struct rockchip_pcie_ep *ep)
pci_epc_mem_exit(ep->epc);
}

+static void rockchip_pcie_ep_hide_msix_cap(struct rockchip_pcie *rockchip)
+{
+ u32 cfg_msi, cfg_msix_cp;
+
+ /*
+ * MSI-X is not supported but the controller still advertises the MSI-X
+ * capability by default, which can lead to the Root Complex side
+ * allocating MSI-X vectors which cannot be used. Avoid this by skipping
+ * the MSI-X capability entry in the PCIe capabilities linked-list: get
+ * the next pointer from the MSI-X entry and set that in the MSI
+ * capability entry (which is the previous entry). This way the MSI-X
+ * entry is skipped (left out of the linked-list) and not advertised.
+ */
+ cfg_msi = rockchip_pcie_read(rockchip, PCIE_EP_CONFIG_BASE +
+ ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
+
+ cfg_msi &= ~ROCKCHIP_PCIE_EP_MSI_CP1_MASK;
+
+ cfg_msix_cp = rockchip_pcie_read(rockchip, PCIE_EP_CONFIG_BASE +
+ ROCKCHIP_PCIE_EP_MSIX_CAP_REG) &
+ ROCKCHIP_PCIE_EP_MSIX_CAP_CP_MASK;
+
+ cfg_msi |= cfg_msix_cp;
+
+ rockchip_pcie_write(rockchip, cfg_msi,
+ PCIE_EP_CONFIG_BASE + ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
+}
+
static int rockchip_pcie_ep_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -588,7 +616,6 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev)
struct rockchip_pcie *rockchip;
struct pci_epc *epc;
int err;
- u32 cfg_msi, cfg_msix_cp;

ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
if (!ep)
@@ -619,6 +646,8 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev)
if (err)
goto err_disable_clocks;

+ rockchip_pcie_ep_hide_msix_cap(rockchip);
+
/* Establish the link automatically */
rockchip_pcie_write(rockchip, PCIE_CLIENT_LINK_TRAIN_ENABLE,
PCIE_CLIENT_CONFIG);
@@ -626,29 +655,6 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev)
/* Only enable function 0 by default */
rockchip_pcie_write(rockchip, BIT(0), PCIE_CORE_PHY_FUNC_CFG);

- /*
- * MSI-X is not supported but the controller still advertises the MSI-X
- * capability by default, which can lead to the Root Complex side
- * allocating MSI-X vectors which cannot be used. Avoid this by skipping
- * the MSI-X capability entry in the PCIe capabilities linked-list: get
- * the next pointer from the MSI-X entry and set that in the MSI
- * capability entry (which is the previous entry). This way the MSI-X
- * entry is skipped (left out of the linked-list) and not advertised.
- */
- cfg_msi = rockchip_pcie_read(rockchip, PCIE_EP_CONFIG_BASE +
- ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
-
- cfg_msi &= ~ROCKCHIP_PCIE_EP_MSI_CP1_MASK;
-
- cfg_msix_cp = rockchip_pcie_read(rockchip, PCIE_EP_CONFIG_BASE +
- ROCKCHIP_PCIE_EP_MSIX_CAP_REG) &
- ROCKCHIP_PCIE_EP_MSIX_CAP_CP_MASK;
-
- cfg_msi |= cfg_msix_cp;
-
- rockchip_pcie_write(rockchip, cfg_msi,
- PCIE_EP_CONFIG_BASE + ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
-
rockchip_pcie_write(rockchip, PCIE_CLIENT_CONF_ENABLE,
PCIE_CLIENT_CONFIG);

--
2.46.2