[PATCH 04/15] NTB: define a new function to get link status

From: Arindam Nath
Date: Wed Feb 05 2020 - 10:55:04 EST


Since getting the status of link is a logically separate
operation, we simply create a new function which will
store the link status to be used later.

Signed-off-by: Arindam Nath <arindam.nath@xxxxxxx>
---
drivers/ntb/hw/amd/ntb_hw_amd.c | 93 ++++++++++++++++++---------------
1 file changed, 50 insertions(+), 43 deletions(-)

diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.c b/drivers/ntb/hw/amd/ntb_hw_amd.c
index 111f33ff2bd7..f50537e0917b 100644
--- a/drivers/ntb/hw/amd/ntb_hw_amd.c
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.c
@@ -195,6 +195,54 @@ static int amd_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
return 0;
}

+static int amd_ntb_get_link_status(struct amd_ntb_dev *ndev)
+{
+ struct pci_dev *pdev = NULL;
+ struct pci_dev *pci_swds = NULL;
+ struct pci_dev *pci_swus = NULL;
+ u32 stat;
+ int rc;
+
+ if (ndev->ntb.topo == NTB_TOPO_SEC) {
+ /* Locate the pointer to Downstream Switch for this device */
+ pci_swds = pci_upstream_bridge(ndev->ntb.pdev);
+ if (pci_swds) {
+ /*
+ * Locate the pointer to Upstream Switch for
+ * the Downstream Switch.
+ */
+ pci_swus = pci_upstream_bridge(pci_swds);
+ if (pci_swus) {
+ rc = pcie_capability_read_dword(pci_swus,
+ PCI_EXP_LNKCTL,
+ &stat);
+ if (rc)
+ return 0;
+ } else {
+ return 0;
+ }
+ } else {
+ return 0;
+ }
+ } else if (ndev->ntb.topo == NTB_TOPO_PRI) {
+ /*
+ * For NTB primary, we simply read the Link Status and control
+ * register of the NTB device itself.
+ */
+ pdev = ndev->ntb.pdev;
+ rc = pcie_capability_read_dword(pdev, PCI_EXP_LNKCTL, &stat);
+ if (rc)
+ return 0;
+ } else {
+ /* Catch all for everything else */
+ return 0;
+ }
+
+ ndev->lnk_sta = stat;
+
+ return 1;
+}
+
static int amd_link_is_up(struct amd_ntb_dev *ndev)
{
if (!ndev->peer_sta)
@@ -845,11 +893,7 @@ static inline void ndev_init_struct(struct amd_ntb_dev *ndev,
static int amd_poll_link(struct amd_ntb_dev *ndev)
{
void __iomem *mmio = ndev->peer_mmio;
- struct pci_dev *pdev = NULL;
- struct pci_dev *pci_swds = NULL;
- struct pci_dev *pci_swus = NULL;
- u32 reg, stat;
- int rc;
+ u32 reg;

reg = readl(mmio + AMD_SIDEINFO_OFFSET);
reg &= NTB_LIN_STA_ACTIVE_BIT;
@@ -861,44 +905,7 @@ static int amd_poll_link(struct amd_ntb_dev *ndev)

ndev->cntl_sta = reg;

- if (ndev->ntb.topo == NTB_TOPO_SEC) {
- /* Locate the pointer to Downstream Switch for this device */
- pci_swds = pci_upstream_bridge(ndev->ntb.pdev);
- if (pci_swds) {
- /*
- * Locate the pointer to Upstream Switch for
- * the Downstream Switch.
- */
- pci_swus = pci_upstream_bridge(pci_swds);
- if (pci_swus) {
- rc = pcie_capability_read_dword(pci_swus,
- PCI_EXP_LNKCTL,
- &stat);
- if (rc)
- return 0;
- } else {
- return 0;
- }
- } else {
- return 0;
- }
- } else if (ndev->ntb.topo == NTB_TOPO_PRI) {
- /*
- * For NTB primary, we simply read the Link Status and control
- * register of the NTB device itself.
- */
- pdev = ndev->ntb.pdev;
- rc = pcie_capability_read_dword(pdev, PCI_EXP_LNKCTL, &stat);
- if (rc)
- return 0;
- } else {
- /* Catch all for everything else */
- return 0;
- }
-
- ndev->lnk_sta = stat;
-
- return 1;
+ return amd_ntb_get_link_status(ndev);
}

static void amd_link_hb(struct work_struct *work)
--
2.17.1