From: Xiaowei Bao <xiaowei.bao@nxp.com>
Date: Fri, 18 Sep 2020 16:00:14 +0800
Subject: PCI: designware-ep: Add the doorbell mode of MSI-X in EP mode

Git-commit: 2f7f7001d0e58f3f1c010c0ccdb049602c889b1d
Patch-mainline: v5.10-rc1
References: bsc#1179344

Add the doorbell mode of MSI-X in DWC EP driver.

Link: https://lore.kernel.org/r/20200918080024.13639-3-Zhiqiang.Hou@nxp.com
Signed-off-by: Xiaowei Bao <xiaowei.bao@nxp.com>
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 .../pci/controller/dwc/pcie-designware-ep.c   | 19 +++++++++++++++++++
 drivers/pci/controller/dwc/pcie-designware.h  | 12 ++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 500d4ca04947..5ae87e8ffb85 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -473,6 +473,25 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
 	return 0;
 }
 
+int dw_pcie_ep_raise_msix_irq_doorbell(struct dw_pcie_ep *ep, u8 func_no,
+				       u16 interrupt_num)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	struct dw_pcie_ep_func *ep_func;
+	u32 msg_data;
+
+	ep_func = dw_pcie_ep_get_func_from_ep(ep, func_no);
+	if (!ep_func || !ep_func->msix_cap)
+		return -EINVAL;
+
+	msg_data = (func_no << PCIE_MSIX_DOORBELL_PF_SHIFT) |
+		   (interrupt_num - 1);
+
+	dw_pcie_writel_dbi(pci, PCIE_MSIX_DOORBELL, msg_data);
+
+	return 0;
+}
+
 int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
 			      u16 interrupt_num)
 {
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 32102ebc5c37..4b75b798de98 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -105,6 +105,9 @@
 #define PCIE_MISC_CONTROL_1_OFF		0x8BC
 #define PCIE_DBI_RO_WR_EN		BIT(0)
 
+#define PCIE_MSIX_DOORBELL		0x948
+#define PCIE_MSIX_DOORBELL_PF_SHIFT	24
+
 #define PCIE_PL_CHK_REG_CONTROL_STATUS			0xB20
 #define PCIE_PL_CHK_REG_CHK_REG_START			BIT(0)
 #define PCIE_PL_CHK_REG_CHK_REG_CONTINUOUS		BIT(1)
@@ -414,6 +417,8 @@ int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
 			     u8 interrupt_num);
 int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
 			     u16 interrupt_num);
+int dw_pcie_ep_raise_msix_irq_doorbell(struct dw_pcie_ep *ep, u8 func_no,
+				       u16 interrupt_num);
 void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar);
 #else
 static inline void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
@@ -455,6 +460,13 @@ static inline int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
 	return 0;
 }
 
+static inline int dw_pcie_ep_raise_msix_irq_doorbell(struct dw_pcie_ep *ep,
+						     u8 func_no,
+						     u16 interrupt_num)
+{
+	return 0;
+}
+
 static inline void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
 {
 }
-- 
2.26.2