PCI: designware-ep: Pre-allocate memory for MSI in dw_pcie_ep_init

Certain SoCs need to map the MSI address in raise_irq.
To map an address, you first need to call pci_epc_mem_alloc_addr(),
however, pci_epc_mem_alloc_addr() calls ioremap() (which can sleep).

Since raise_irq is only called from atomic context, we can't call
pci_epc_mem_alloc_addr() from raise_irq.

Pre-allocate a page in dw_pcie_ep_init(), so that this page can later
be used to map/unmap the MSI address in raise_irq.

Tested-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Joao Pinto <jpinto@synopsys.com>

diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index 3fb34be..8d8019c 100644 (file)
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -286,6 +286,9 @@ void dw_pcie_ep_exit(struct dw_pcie_ep *ep)
 {
        struct pci_epc *epc = ep->epc;
 
+       pci_epc_mem_free_addr(epc, ep->msi_mem_phys, ep->msi_mem,
+                             epc->mem->page_size);
+
        pci_epc_mem_exit(epc);
 }
 
@@ -341,6 +344,13 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
                return ret;
        }
 
+       ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
+                                            epc->mem->page_size);
+       if (!ep->msi_mem) {
+               dev_err(dev, "Failed to reserve memory for MSI\n");
+               return -ENOMEM;
+       }
+
        ep->epc = epc;
        epc_set_drvdata(epc, ep);
        dw_pcie_setup(pci);

diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index 9aaf0cd..5a1da45 100644 (file)
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -198,6 +198,8 @@ struct dw_pcie_ep {
        unsigned long           ob_window_map;
        u32                     num_ib_windows;
        u32                     num_ob_windows;
+       void __iomem            *msi_mem;
+       phys_addr_t             msi_mem_phys;
 };
 
 struct dw_pcie_ops {