From: Pali Rohár pali@kernel.org
stable inclusion from stable-5.10.80 commit bd5d982822cf2b14c2d6aff5a43a5f667c56c758 bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit bc4fac42e5f8460af09c0a7f2f1915be09e20c71 upstream.
Aardvark supports PCIe Hot Reset via PCIE_CORE_CTRL1_REG.
Use it for implementing PCI_BRIDGE_CTL_BUS_RESET bit of PCI_BRIDGE_CONTROL register on emulated bridge.
With this, the function pci_reset_secondary_bus() starts working and can reset connected PCIe card. Custom userspace script [1] which uses setpci can trigger PCIe Hot Reset and reset the card manually.
[1] https://alexforencich.com/wiki/en/pcie/hot-reset-linux
Link: https://lore.kernel.org/r/20211028185659.20329-7-kabel@kernel.org Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space") 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 Signed-off-by: Chen Jun chenjun102@huawei.com Reviewed-by: Weilong Chen chenweilong@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/pci/controller/pci-aardvark.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)
diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index eec9bb7c7a80..0a2d89425740 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -793,6 +793,22 @@ advk_pci_bridge_emul_base_conf_read(struct pci_bridge_emul *bridge, *value = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG); return PCI_BRIDGE_EMUL_HANDLED;
+ case PCI_INTERRUPT_LINE: { + /* + * From the whole 32bit register we support reading from HW only + * one bit: PCI_BRIDGE_CTL_BUS_RESET. + * Other bits are retrieved only from emulated config buffer. + */ + __le32 *cfgspace = (__le32 *)&bridge->conf; + u32 val = le32_to_cpu(cfgspace[PCI_INTERRUPT_LINE / 4]); + if (advk_readl(pcie, PCIE_CORE_CTRL1_REG) & HOT_RESET_GEN) + val |= PCI_BRIDGE_CTL_BUS_RESET << 16; + else + val &= ~(PCI_BRIDGE_CTL_BUS_RESET << 16); + *value = val; + return PCI_BRIDGE_EMUL_HANDLED; + } + default: return PCI_BRIDGE_EMUL_NOT_HANDLED; } @@ -809,6 +825,17 @@ advk_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge, advk_writel(pcie, new, PCIE_CORE_CMD_STATUS_REG); break;
+ case PCI_INTERRUPT_LINE: + if (mask & (PCI_BRIDGE_CTL_BUS_RESET << 16)) { + u32 val = advk_readl(pcie, PCIE_CORE_CTRL1_REG); + if (new & (PCI_BRIDGE_CTL_BUS_RESET << 16)) + val |= HOT_RESET_GEN; + else + val &= ~HOT_RESET_GEN; + advk_writel(pcie, val, PCIE_CORE_CTRL1_REG); + } + break; + default: break; }