From:   Rick Wertenbroek <rick.wertenbroek@gmail.com>
To:     alberto.dassatti@heig-vd.ch
Cc:     xxm@rock-chips.com, rick.wertenbroek@heig-vd.ch,
        Rick Wertenbroek <rick.wertenbroek@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Heiko Stuebner <heiko@sntech.de>,
        Shawn Lin <shawn.lin@rock-chips.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Jani Nikula <jani.nikula@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        Mikko Kovanen <mikko.kovanen@aavamobile.com>,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-pci@vger.kernel.org
Subject: [PATCH v2 9/9] PCI: rockchip: Add parameter check for RK3399 PCIe endpoint core set_msi()
Date:   Tue, 14 Feb 2023 15:08:57 +0100
Message-Id: <20230214140858.1133292-10-rick.wertenbroek@gmail.com>
In-Reply-To: <20230214140858.1133292-1-rick.wertenbroek@gmail.com>
References: <20230214140858.1133292-1-rick.wertenbroek@gmail.com>
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The RK3399 PCIe endpoint core supports only a single PCIe physcial
function (function number 0), therefore return -EINVAL if set_msi() is
called with a function number greater than 0.
The PCIe standard only allows the multi message capability (MMC) value
to be up to 0x5 (32 messages), therefore return -EINVAL if set_msi() is
called with a MMC value of over 0x5.

Signed-off-by: Rick Wertenbroek <rick.wertenbroek@gmail.com>
---
 drivers/pci/controller/pcie-rockchip-ep.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index b7865a94e..80634b690 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -294,6 +294,16 @@ static int rockchip_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 vfn,
 	struct rockchip_pcie *rockchip = &ep->rockchip;
 	u32 flags;
 
+	if (fn) {
+		dev_err(&epc->dev, "This endpoint controller only supports a single physical function\n");
+		return -EINVAL;
+	}
+
+	if (mmc > 0x5) {
+		dev_err(&epc->dev, "Number of MSI IRQs cannot be more than 32\n");
+		return -EINVAL;
+	}
+
 	flags = rockchip_pcie_read(rockchip,
 				   ROCKCHIP_PCIE_EP_FUNC_BASE(fn) +
 				   ROCKCHIP_PCIE_EP_MSI_CTRL_REG);
-- 
2.25.1