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From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Date: Wed, 27 Mar 2024 14:43:34 +0530
Subject: [PATCH v12 5/8] PCI: dwc: ep: Introduce dw_pcie_ep_cleanup() API
 for drivers supporting PERST#
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Message-Id: <20240327-pci-dbi-rework-v12-5-082625472414@linaro.org>
References: <20240327-pci-dbi-rework-v12-0-082625472414@linaro.org>
In-Reply-To: <20240327-pci-dbi-rework-v12-0-082625472414@linaro.org>
To: Jingoo Han <jingoohan1@gmail.com>, 
 Lorenzo Pieralisi <lpieralisi@kernel.org>, 
 =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= <kw@linux.com>, 
 Rob Herring <robh@kernel.org>, Bjorn Helgaas <bhelgaas@google.com>, 
 Marek Vasut <marek.vasut+renesas@gmail.com>, 
 Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>, 
 Thierry Reding <thierry.reding@gmail.com>, 
 Jonathan Hunter <jonathanh@nvidia.com>, Vidya Sagar <vidyas@nvidia.com>, 
 Vignesh Raghavendra <vigneshr@ti.com>, Richard Zhu <hongxing.zhu@nxp.com>, 
 Lucas Stach <l.stach@pengutronix.de>, Shawn Guo <shawnguo@kernel.org>, 
 Sascha Hauer <s.hauer@pengutronix.de>, 
 Pengutronix Kernel Team <kernel@pengutronix.de>, 
 Fabio Estevam <festevam@gmail.com>, NXP Linux Team <linux-imx@nxp.com>, 
 Minghuan Lian <minghuan.Lian@nxp.com>, Mingkai Hu <mingkai.hu@nxp.com>, 
 Roy Zang <roy.zang@nxp.com>, 
 Kunihiko Hayashi <hayashi.kunihiko@socionext.com>, 
 Masami Hiramatsu <mhiramat@kernel.org>, 
 Kishon Vijay Abraham I <kishon@kernel.org>, 
 Jesper Nilsson <jesper.nilsson@axis.com>, 
 Srikanth Thokala <srikanth.thokala@intel.com>, 
 Shawn Lin <shawn.lin@rock-chips.com>, Heiko Stuebner <heiko@sntech.de>, 
 Kishon Vijay Abraham I <kishon@kernel.org>
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, 
 linux-renesas-soc@vger.kernel.org, linux-arm-msm@vger.kernel.org, 
 linux-tegra@vger.kernel.org, linux-omap@vger.kernel.org, 
 linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, 
 Niklas Cassel <cassel@kernel.org>, linux-arm-kernel@axis.com, 
 linux-rockchip@lists.infradead.org, 
 Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>, 
 Frank Li <Frank.Li@nxp.com>

For DWC glue drivers supporting PERST# (currently Qcom and Tegra194), some
of the DWC resources like eDMA should be cleaned up during the PERST#
assert time.

So let's introduce a dw_pcie_ep_cleanup() API that could be called by these
drivers to cleanup the DWC specific resources. Currently, it just removes
eDMA.

Reported-by: Niklas Cassel <cassel@kernel.org>
Closes: https://lore.kernel.org/linux-pci/ZWYmX8Y%2F7Q9WMxES@x1-carbon
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/controller/dwc/pcie-designware-ep.c | 19 +++++++++++++++++--
 drivers/pci/controller/dwc/pcie-designware.h    |  5 +++++
 drivers/pci/controller/dwc/pcie-qcom-ep.c       |  1 +
 drivers/pci/controller/dwc/pcie-tegra194.c      |  2 ++
 4 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index d87f7642d7f6..eeff7f1ff8f1 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -619,6 +619,22 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
 	return 0;
 }
 
+/**
+ * dw_pcie_ep_cleanup - Cleanup DWC EP resources after fundamental reset
+ * @ep: DWC EP device
+ *
+ * Cleans up the DWC EP specific resources like eDMA etc... after fundamental
+ * reset like PERST#. Note that this API is only applicable for drivers
+ * supporting PERST# or any other methods of fundamental reset.
+ */
+void dw_pcie_ep_cleanup(struct dw_pcie_ep *ep)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+
+	dw_pcie_edma_remove(pci);
+}
+EXPORT_SYMBOL_GPL(dw_pcie_ep_cleanup);
+
 /**
  * dw_pcie_ep_deinit - Deinitialize the endpoint device
  * @ep: DWC EP device
@@ -628,10 +644,9 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
  */
 void dw_pcie_ep_deinit(struct dw_pcie_ep *ep)
 {
-	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
 	struct pci_epc *epc = ep->epc;
 
-	dw_pcie_edma_remove(pci);
+	dw_pcie_ep_cleanup(ep);
 
 	pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
 			      epc->mem->window.page_size);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 61465203bb60..351d2fe3ea4d 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -672,6 +672,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep);
 int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep);
 void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep);
 void dw_pcie_ep_deinit(struct dw_pcie_ep *ep);
+void dw_pcie_ep_cleanup(struct dw_pcie_ep *ep);
 int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no);
 int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
 			     u8 interrupt_num);
@@ -705,6 +706,10 @@ static inline void dw_pcie_ep_deinit(struct dw_pcie_ep *ep)
 {
 }
 
+static inline void dw_pcie_ep_cleanup(struct dw_pcie_ep *ep)
+{
+}
+
 static inline int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no)
 {
 	return 0;
diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
index 36e5e80cd22f..59b1c0110288 100644
--- a/drivers/pci/controller/dwc/pcie-qcom-ep.c
+++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
@@ -507,6 +507,7 @@ static void qcom_pcie_perst_assert(struct dw_pcie *pci)
 		return;
 	}
 
+	dw_pcie_ep_cleanup(&pci->ep);
 	qcom_pcie_disable_resources(pcie_ep);
 	pcie_ep->link_status = QCOM_PCIE_EP_LINK_DISABLED;
 }
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 1f7b662cb8e1..26ea2f8313eb 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -1715,6 +1715,8 @@ static void pex_ep_event_pex_rst_assert(struct tegra_pcie_dw *pcie)
 	if (ret)
 		dev_err(pcie->dev, "Failed to go Detect state: %d\n", ret);
 
+	dw_pcie_ep_cleanup(&pcie->pci.ep);
+
 	reset_control_assert(pcie->core_rst);
 
 	tegra_pcie_disable_phy(pcie);

-- 
2.25.1