PCI: aardvark: Fix preserving PCI_EXP_RTCTL_CRSSVE flag on emulated bridge

[ Upstream commit d419052bc6c60fa4ab2b5a51d5f1e55a66e2b4ff ]

Commit 43f5c77bcbd2 ("PCI: aardvark: Fix reporting CRS value") started
using CRSSVE flag for handling CRS responses.

PCI_EXP_RTCTL_CRSSVE flag is stored only in emulated config space buffer
and there is handler for PCI_EXP_RTCTL register. So every read operation
from config space automatically clears CRSSVE flag as it is not defined in
PCI_EXP_RTCTL read handler.

Fix this by reading current CRSSVE bit flag from emulated space buffer and
appending it to PCI_EXP_RTCTL read response.

Link: https://lore.kernel.org/r/20211005180952.6812-5-kabel@kernel.org
Fixes: 43f5c77bcbd2 ("PCI: aardvark: Fix reporting CRS value")
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>
Reviewed-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 65762fd..5b34dea 100644 (file)
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -885,6 +885,7 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
        case PCI_EXP_RTCTL: {
                u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG);
                *value = (val & PCIE_MSG_PM_PME_MASK) ? 0 : PCI_EXP_RTCTL_PMEIE;
+               *value |= le16_to_cpu(bridge->pcie_conf.rootctl) & PCI_EXP_RTCTL_CRSSVE;
                *value |= PCI_EXP_RTCAP_CRSVIS << 16;
                return PCI_BRIDGE_EMUL_HANDLED;
        }