[PATCH 2/3] PCI: dwc: Use cached PCIe capability offset in core

Hans Zhang 18255117159 at 163.com
Sat May 9 06:51:51 PDT 2026


Modify the DWC core functions to use the cached pcie_cap offset instead
of calling dw_pcie_find_capability() each time.

Signed-off-by: Hans Zhang <18255117159 at 163.com>
---
 drivers/pci/controller/dwc/pcie-designware-ep.c  |  4 +++-
 .../pci/controller/dwc/pcie-designware-host.c    |  4 +++-
 drivers/pci/controller/dwc/pcie-designware.c     | 16 ++++++----------
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index d4dc3b24da60..fdcb9012058d 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -1128,7 +1128,7 @@ static void dw_pcie_ep_init_non_sticky_registers(struct dw_pcie *pci)
 	 * to all other functions as well.
 	 */
 	if (funcs > 1) {
-		offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+		offset = dw_pcie_get_pcie_cap(pci);
 		func0_lnkcap = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
 		func0_lnkcap = FIELD_GET(PCI_EXP_LNKCAP_MLW |
 					 PCI_EXP_LNKCAP_SLS, func0_lnkcap);
@@ -1390,6 +1390,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 	ep->msi_msg_addr = 0;
 	ep->msi_map_size = 0;
 
+	dw_pcie_get_pcie_cap(pci);
+
 	epc = devm_pci_epc_create(dev, &epc_ops);
 	if (IS_ERR(epc)) {
 		dev_err(dev, "Failed to create epc device\n");
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index c9517a348836..7b3ba83ed616 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -575,6 +575,8 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp)
 
 	raw_spin_lock_init(&pp->lock);
 
+	dw_pcie_get_pcie_cap(pci);
+
 	bridge = devm_pci_alloc_host_bridge(dev, 0);
 	if (!bridge)
 		return -ENOMEM;
@@ -1218,7 +1220,7 @@ static int dw_pcie_pme_turn_off(struct dw_pcie *pci)
 
 int dw_pcie_suspend_noirq(struct dw_pcie *pci)
 {
-	u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u8 offset = pci->pcie_cap;
 	int ret = 0;
 	u32 val;
 
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index c11cf61b8319..db62b93c6255 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -761,7 +761,7 @@ const char *dw_pcie_ltssm_status_string(enum dw_pcie_ltssm ltssm)
  */
 int dw_pcie_wait_for_link(struct dw_pcie *pci)
 {
-	u32 offset, val, ltssm;
+	u32 val, ltssm;
 	int retries;
 
 	/* Check if the link is up or not */
@@ -807,8 +807,7 @@ int dw_pcie_wait_for_link(struct dw_pcie *pci)
 	if (pci->max_link_speed > 2)
 		msleep(PCIE_RESET_CONFIG_WAIT_MS);
 
-	offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
-	val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA);
+	val = dw_pcie_readw_dbi(pci, pci->pcie_cap + PCI_EXP_LNKSTA);
 
 	dev_info(pci->dev, "PCIe Gen.%u x%u link up\n",
 		 FIELD_GET(PCI_EXP_LNKSTA_CLS, val),
@@ -844,7 +843,7 @@ EXPORT_SYMBOL_GPL(dw_pcie_upconfig_setup);
 static void dw_pcie_link_set_max_speed(struct dw_pcie *pci)
 {
 	u32 cap, ctrl2, link_speed;
-	u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u8 offset = pci->pcie_cap;
 
 	cap = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP);
 
@@ -890,8 +889,7 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci)
 
 int dw_pcie_link_get_max_link_width(struct dw_pcie *pci)
 {
-	u8 cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
-	u32 lnkcap = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP);
+	u32 lnkcap = dw_pcie_readl_dbi(pci, pci->pcie_cap + PCI_EXP_LNKCAP);
 
 	return FIELD_GET(PCI_EXP_LNKCAP_MLW, lnkcap);
 }
@@ -899,7 +897,6 @@ int dw_pcie_link_get_max_link_width(struct dw_pcie *pci)
 static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes)
 {
 	u32 lnkcap, lwsc, plc;
-	u8 cap;
 
 	if (!num_lanes)
 		return;
@@ -936,11 +933,10 @@ static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes)
 	dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, plc);
 	dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, lwsc);
 
-	cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
-	lnkcap = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP);
+	lnkcap = dw_pcie_readl_dbi(pci, pci->pcie_cap + PCI_EXP_LNKCAP);
 	lnkcap &= ~PCI_EXP_LNKCAP_MLW;
 	lnkcap |= FIELD_PREP(PCI_EXP_LNKCAP_MLW, num_lanes);
-	dw_pcie_writel_dbi(pci, cap + PCI_EXP_LNKCAP, lnkcap);
+	dw_pcie_writel_dbi(pci, pci->pcie_cap + PCI_EXP_LNKCAP, lnkcap);
 }
 
 void dw_pcie_iatu_detect(struct dw_pcie *pci)
-- 
2.34.1




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