[PATCH 4/4] PCI: rcar: Teardown MSI setup if rcar_pcie_enable() fails

[Marek Vasut]

If the rcar_pcie_enable() fails and MSIs are enabled, the setup done in
rcar_pcie_enable_msi() is never undone. Add a function to tear down the
MSI setup by disabling the MSI handling in the PCIe block, deallocating
the pages requested for the MSIs and zapping the IRQ mapping.

Signed-off-by: Marek Vasut <marek.vasut+rene...@gmail.com>
Cc: Geert Uytterhoeven <geert+rene...@glider.be>
Cc: Phil Edworthy <phil.edwor...@renesas.com>
Cc: Simon Horman <horms+rene...@verge.net.au>
Cc: Wolfram Sang <w...@the-dreams.de>
Cc: linux-renesas-soc@vger.kernel.org
---
 drivers/pci/host/pcie-rcar.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index 3cc84f7e05f7..5c365f743df5 100644
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -900,6 +900,28 @@ static int rcar_pcie_enable_msi(struct rcar_pcie *pcie)
        return err;
 }
 
+static void rcar_pcie_teardown_msi(struct rcar_pcie *pcie)
+{
+       struct rcar_msi *msi = &pcie->msi;
+       int irq, i;
+
+       /* Disable all MSI interrupts */
+       rcar_pci_write_reg(pcie, 0, PCIEMSIIER);
+
+       /* Disable address decoding of the MSI interrupt, MSIFE */
+       rcar_pci_write_reg(pcie, 0, PCIEMSIALR);
+
+       free_pages(msi->pages, 0);
+
+       for (i = 0; i < INT_PCI_MSI_NR; i++) {
+               irq = irq_find_mapping(msi->domain, i);
+               if (irq > 0)
+                       irq_dispose_mapping(irq);
+       }
+
+       irq_domain_remove(msi->domain);
+}
+
 static int rcar_pcie_get_resources(struct rcar_pcie *pcie)
 {
        struct device *dev = pcie->dev;
@@ -1156,10 +1178,14 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 
        err = rcar_pcie_enable(pcie);
        if (err)
-               goto err_clk_disable;
+               goto err_msi_teardown;
 
        return 0;
 
+err_msi_teardown:
+       if (IS_ENABLED(CONFIG_PCI_MSI))
+               rcar_pcie_teardown_msi(pcie);
+
 err_clk_disable:
        clk_disable_unprepare(pcie->bus_clk);
 
-- 
2.16.2