[PATCH 5.15 149/917] PCI: aardvark: Read all 16-bits from PCIE_MSI_PAYLOAD_REG

Greg Kroah-Hartman
2021-11-15T23:31:20Z

From: Marek Behún <kabel@kernel.org>

commit 95997723b6402cd6c53e0f9e7ac640ec64eaaff8 upstream.

The PCIE_MSI_PAYLOAD_REG contains 16-bit MSI number, not only lower
8 bits. Fix reading content of this register and add a comment
describing the access to this register.

Link: https://lore.kernel.org/r/20211028185659.20329-4-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pci/controller/pci-aardvark.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -119,6 +119,7 @@
#define PCIE_MSI_STATUS_REG (CONTROL_BASE_ADDR + 0x58)
#define PCIE_MSI_MASK_REG (CONTROL_BASE_ADDR + 0x5C)
#define PCIE_MSI_PAYLOAD_REG (CONTROL_BASE_ADDR + 0x9C)
+#define PCIE_MSI_DATA_MASK GENMASK(15, 0)

/* PCIe window configuration */
#define OB_WIN_BASE_ADDR 0x4c00
@@ -1361,8 +1362,12 @@ static void advk_pcie_handle_msi(struct
if (!(BIT(msi_idx) & msi_status))
continue;

+ /*
+ * msi_idx contains bits [4:0] of the msi_data and msi_data
+ * contains 16bit MSI interrupt number
+ */
advk_writel(pcie, BIT(msi_idx), PCIE_MSI_STATUS_REG);
- msi_data = advk_readl(pcie, PCIE_MSI_PAYLOAD_REG) & 0xFF;
+ msi_data = advk_readl(pcie, PCIE_MSI_PAYLOAD_REG) & PCIE_MSI_DATA_MASK;
generic_handle_irq(msi_data);
}