From: Olof Johansson olof@lixom.net
mainline inclusion from mainline-v5.5-rc1 commit 35a0b2378c199d4f26e458b2ca38ea56aaf2d9b8 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V CVE: NA
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commit 35a0b2378c199d4f26e458b2ca38ea56aaf2d9b8 upstream. Backport summary: for 4.19 kernel ICX PCIe Gen4 support.
Prior to eed85ff4c0da7 ("PCI/DPC: Enable DPC only if AER is available"), Linux handled DPC events regardless of whether firmware had granted it ownership of AER or DPC, e.g., via _OSC.
PCIe r5.0, sec 6.2.10, recommends that the OS link control of DPC to control of AER, so after eed85ff4c0da7, Linux handles DPC events only if it has control of AER.
On platforms that do not grant OS control of AER via _OSC, Linux DPC handling worked before eed85ff4c0da7 but not after.
To make Linux DPC handling work on those platforms the same way they did before, add a "pcie_ports=dpc-native" kernel parameter that makes Linux handle DPC events regardless of whether it has control of AER.
[bhelgaas: commit log, move pcie_ports_dpc_native to drivers/pci/] Link: https://lore.kernel.org/r/20191023192205.97024-1-olof@lixom.net Signed-off-by: Olof Johansson olof@lixom.net Signed-off-by: Bjorn Helgaas bhelgaas@google.com
(cherry picked from commit 35a0b2378c199d4f26e458b2ca38ea56aaf2d9b8) Signed-off-by: Ethan Zhao haifeng.zhao@intel.com Signed-off-by: Jackie Liu liuyun01@kylinos.cn Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- Documentation/admin-guide/kernel-parameters.txt | 2 ++ drivers/pci/pcie/dpc.c | 2 +- drivers/pci/pcie/portdrv.h | 2 ++ drivers/pci/pcie/portdrv_core.c | 11 ++++++++--- drivers/pci/pcie/portdrv_pci.c | 8 ++++++++ 5 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 25f4f61e967a6..257b0d12f6e81 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3555,6 +3555,8 @@ even if the platform doesn't give the OS permission to use them. This may cause conflicts if the platform also tries to use these services. + dpc-native Use native PCIe service for DPC only. May + cause conflicts if firmware uses AER or DPC. compat Disable native PCIe services (PME, AER, DPC, PCIe hotplug).
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c index a32ec3487a8d0..e06f42f58d3d4 100644 --- a/drivers/pci/pcie/dpc.c +++ b/drivers/pci/pcie/dpc.c @@ -291,7 +291,7 @@ static int dpc_probe(struct pcie_device *dev) int status; u16 ctl, cap;
- if (pcie_aer_get_firmware_first(pdev)) + if (pcie_aer_get_firmware_first(pdev) && !pcie_ports_dpc_native) return -ENOTSUPP;
dpc = devm_kzalloc(device, sizeof(*dpc), GFP_KERNEL); diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h index 55fe9f7602dec..c42cb76fa67fe 100644 --- a/drivers/pci/pcie/portdrv.h +++ b/drivers/pci/pcie/portdrv.h @@ -23,6 +23,8 @@
#define PCIE_PORT_DEVICE_MAXSERVICES 4
+extern bool pcie_ports_dpc_native; + #ifdef CONFIG_PCIEAER int pcie_aer_init(void); #else diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index a3d1cc42a3937..54772e5b7f8e4 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -248,9 +248,14 @@ static int get_port_device_capability(struct pci_dev *dev) pcie_pme_interrupt_enable(dev, false); }
- if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) && - pci_aer_available() && services & PCIE_PORT_SERVICE_AER) - services |= PCIE_PORT_SERVICE_DPC; + /* + * With dpc-native, allow Linux to use DPC even if it doesn't have + * permission to use AER. + */ + if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) && + pci_aer_available() && + (pcie_ports_dpc_native || (services & PCIE_PORT_SERVICE_AER))) + services |= PCIE_PORT_SERVICE_DPC;
return services; } diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index e6671fec17e1a..94c2fd71c6ca2 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -29,12 +29,20 @@ bool pcie_ports_disabled; */ bool pcie_ports_native;
+/* + * If the user specified "pcie_ports=dpc-native", use the Linux DPC PCIe + * service even if the platform hasn't given us permission. + */ +bool pcie_ports_dpc_native; + static int __init pcie_port_setup(char *str) { if (!strncmp(str, "compat", 6)) pcie_ports_disabled = true; else if (!strncmp(str, "native", 6)) pcie_ports_native = true; + else if (!strncmp(str, "dpc-native", 10)) + pcie_ports_dpc_native = true;
return 1; }