[PATCH v12 5/8] PCI: dwc: ep: Introduce dw_pcie_ep_cleanup() API for drivers supporting PERST#

Manivannan Sadhasivam
2024-03-27T09:15:44Z

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