linux-kernel - [PATCH v3 3/3] PCI: dw-rockchip: Unify link status checks with FIELD

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250423153214.16405-4-18255117159@163.com>
Date: Wed, 23 Apr 2025 23:32:14 +0800
From: Hans Zhang <18255117159@....com>
To: lpieralisi@...nel.org,
	kw@...ux.com,
	bhelgaas@...gle.com,
	heiko@...ech.de
Cc: manivannan.sadhasivam@...aro.org,
	robh@...nel.org,
	jingoohan1@...il.com,
	shawn.lin@...k-chips.com,
	linux-pci@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-rockchip@...ts.infradead.org,
	Hans Zhang <18255117159@....com>,
	Niklas Cassel <cassel@...nel.org>
Subject: [PATCH v3 3/3] PCI: dw-rockchip: Unify link status checks with FIELD_GET

Link-up detection manually checked PCIE_LINKUP bits across RC/EP modes,
leading to code duplication. Centralize the logic using FIELD_GET. This
removes redundancy and abstracts hardware-specific bit masking, ensuring
consistent link state handling.

Signed-off-by: Hans Zhang <18255117159@....com>
Reviewed-by: Niklas Cassel <cassel@...nel.org>
---
 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 21 +++++++------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index 96ca394da42c..f2f8d8ada7a5 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -8,6 +8,7 @@
  * Author: Simon Xue <xxm@...k-chips.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/gpio/consumer.h>
 #include <linux/irqchip/chained_irq.h>
@@ -73,9 +74,8 @@
 
 /* LTSSM Status Register */
 #define PCIE_CLIENT_LTSSM_STATUS	0x300
-#define  PCIE_SMLH_LINKUP		BIT(16)
-#define  PCIE_RDLH_LINKUP		BIT(17)
-#define  PCIE_LINKUP			(PCIE_SMLH_LINKUP | PCIE_RDLH_LINKUP)
+#define  PCIE_LINKUP			0x3
+#define  PCIE_LINKUP_MASK		GENMASK(17, 16)
 #define  PCIE_LTSSM_STATUS_MASK		GENMASK(5, 0)
 
 struct rockchip_pcie {
@@ -209,10 +209,7 @@ static int rockchip_pcie_link_up(struct dw_pcie *pci)
 	struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
 	u32 val = rockchip_pcie_get_ltssm(rockchip);
 
-	if ((val & PCIE_LINKUP) == PCIE_LINKUP)
-		return 1;
-
-	return 0;
+	return FIELD_GET(PCIE_LINKUP_MASK, val) == PCIE_LINKUP;
 }
 
 static void rockchip_pcie_enable_l0s(struct dw_pcie *pci)
@@ -512,7 +509,7 @@ static irqreturn_t rockchip_pcie_rc_sys_irq_thread(int irq, void *arg)
 	struct dw_pcie *pci = &rockchip->pci;
 	struct dw_pcie_rp *pp = &pci->pp;
 	struct device *dev = pci->dev;
-	u32 reg, val;
+	u32 reg;
 
 	reg = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_INTR_STATUS_MISC);
 	rockchip_pcie_writel_apb(rockchip, reg, PCIE_CLIENT_INTR_STATUS_MISC);
@@ -521,8 +518,7 @@ static irqreturn_t rockchip_pcie_rc_sys_irq_thread(int irq, void *arg)
 	dev_dbg(dev, "LTSSM_STATUS: %#x\n", rockchip_pcie_get_ltssm(rockchip));
 
 	if (reg & PCIE_RDLH_LINK_UP_CHGED) {
-		val = rockchip_pcie_get_ltssm(rockchip);
-		if ((val & PCIE_LINKUP) == PCIE_LINKUP) {
+		if (rockchip_pcie_link_up(pci)) {
 			dev_dbg(dev, "Received Link up event. Starting enumeration!\n");
 			/* Rescan the bus to enumerate endpoint devices */
 			pci_lock_rescan_remove();
@@ -539,7 +535,7 @@ static irqreturn_t rockchip_pcie_ep_sys_irq_thread(int irq, void *arg)
 	struct rockchip_pcie *rockchip = arg;
 	struct dw_pcie *pci = &rockchip->pci;
 	struct device *dev = pci->dev;
-	u32 reg, val;
+	u32 reg;
 
 	reg = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_INTR_STATUS_MISC);
 	rockchip_pcie_writel_apb(rockchip, reg, PCIE_CLIENT_INTR_STATUS_MISC);
@@ -553,8 +549,7 @@ static irqreturn_t rockchip_pcie_ep_sys_irq_thread(int irq, void *arg)
 	}
 
 	if (reg & PCIE_RDLH_LINK_UP_CHGED) {
-		val = rockchip_pcie_get_ltssm(rockchip);
-		if ((val & PCIE_LINKUP) == PCIE_LINKUP) {
+		if (rockchip_pcie_link_up(pci)) {
 			dev_dbg(dev, "link up\n");
 			dw_pcie_ep_linkup(&pci->ep);
 		}
-- 
2.25.1