From: Ilpo Järvinen ilpo.jarvinen@linux.intel.com

[ Upstream commit e5321ae10e1323359a5067a26dfe98b5f44cc5e6 ]

eetlp_prefix_path in the struct pci_dev tells if End-End TLP Prefixes are supported by the path or not, and the value is only calculated if CONFIG_PCI_PASID is set.

The Max End-End TLP Prefixes field in the Device Capabilities Register 2 also tells how many (1-4) End-End TLP Prefixes are supported (PCIe r6.2 sec 7.5.3.15). The number of supported End-End Prefixes is useful for reading correct number of DWORDs from TLP Prefix Log register in AER capability (PCIe r6.2 sec 7.8.4.12).

Replace eetlp_prefix_path with eetlp_prefix_max and determine the number of supported End-End Prefixes regardless of CONFIG_PCI_PASID so that an upcoming commit generalizing TLP Prefix Log register reading does not have to read extra DWORDs for End-End Prefixes that never will be there.

The value stored into eetlp_prefix_max is directly derived from device's Max End-End TLP Prefixes and does not consider limitations imposed by bridges or the Root Port beyond supported/not supported flags. This is intentional for two reasons:

1) PCIe r6.2 spec sections 2.2.10.4 & 6.2.4.4 indicate that a TLP is malformed only if the number of prefixes exceed the number of Max End-End TLP Prefixes, which seems to be the case even if the device could never receive that many prefixes due to smaller maximum imposed by a bridge or the Root Port. If TLP parsing is later added, this distinction is significant in interpreting what is logged by the TLP Prefix Log registers and the value matching to the Malformed TLP threshold is going to be more useful.

2) TLP Prefix handling happens autonomously on a low layer and the value in eetlp_prefix_max is not programmed anywhere by the kernel (i.e., there is no limiter OS can control to prevent sending more than N TLP Prefixes).

Link: https://lore.kernel.org/r/20250114170840.1633-7-ilpo.jarvinen@linux.intel.co... Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Reviewed-by: Yazen Ghannam yazen.ghannam@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/ats.c | 2 +- drivers/pci/probe.c | 14 +++++++++----- include/linux/pci.h | 2 +- include/uapi/linux/pci_regs.h | 1 + 4 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index c967ad6e26267..17a3894baf6be 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -376,7 +376,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features) if (WARN_ON(pdev->pasid_enabled)) return -EBUSY;

- if (!pdev->eetlp_prefix_path && !pdev->pasid_no_tlp) + if (!pdev->eetlp_prefix_max && !pdev->pasid_no_tlp) return -EINVAL;

if (!pasid) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 5c1ab9ee65eb3..b47b33c48f33f 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2227,8 +2227,8 @@ static void pci_configure_ltr(struct pci_dev *dev)

static void pci_configure_eetlp_prefix(struct pci_dev *dev) { -#ifdef CONFIG_PCI_PASID struct pci_dev *bridge; + unsigned int eetlp_max; int pcie_type; u32 cap;

@@ -2240,15 +2240,19 @@ static void pci_configure_eetlp_prefix(struct pci_dev *dev) return;

pcie_type = pci_pcie_type(dev); + + eetlp_max = FIELD_GET(PCI_EXP_DEVCAP2_EE_PREFIX_MAX, cap); + /* 00b means 4 */ + eetlp_max = eetlp_max ?: 4; + if (pcie_type == PCI_EXP_TYPE_ROOT_PORT || pcie_type == PCI_EXP_TYPE_RC_END) - dev->eetlp_prefix_path = 1; + dev->eetlp_prefix_max = eetlp_max; else { bridge = pci_upstream_bridge(dev); - if (bridge && bridge->eetlp_prefix_path) - dev->eetlp_prefix_path = 1; + if (bridge && bridge->eetlp_prefix_max) + dev->eetlp_prefix_max = eetlp_max; } -#endif }

static void pci_configure_serr(struct pci_dev *dev) diff --git a/include/linux/pci.h b/include/linux/pci.h index 28f91982402aa..25deb09f9fce9 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -396,7 +396,7 @@ struct pci_dev { u16 l1ss; /* L1SS Capability pointer */ #endif unsigned int pasid_no_tlp:1; /* PASID works without TLP Prefix */ - unsigned int eetlp_prefix_path:1; /* End-to-End TLP Prefix */ + unsigned int eetlp_prefix_max:3; /* Max # of End-End TLP Prefixes, 0=not supported */

pci_channel_state_t error_state; /* Current connectivity state */ struct device dev; /* Generic device interface */ diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index 3325155036c80..1426896f4625b 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -659,6 +659,7 @@ #define PCI_EXP_DEVCAP2_OBFF_MSG 0x00040000 /* New message signaling */ #define PCI_EXP_DEVCAP2_OBFF_WAKE 0x00080000 /* Re-use WAKE# for OBFF */ #define PCI_EXP_DEVCAP2_EE_PREFIX 0x00200000 /* End-End TLP Prefix */ +#define PCI_EXP_DEVCAP2_EE_PREFIX_MAX 0x00c00000 /* Max End-End TLP Prefixes */ #define PCI_EXP_DEVCTL2 0x28 /* Device Control 2 */ #define PCI_EXP_DEVCTL2_COMP_TIMEOUT 0x000f /* Completion Timeout Value */ #define PCI_EXP_DEVCTL2_COMP_TMOUT_DIS 0x0010 /* Completion Timeout Disable */

From: Rakesh Babu Saladi Saladi.Rakeshbabu@microchip.com

[ Upstream commit a3282f84b2151d254dc4abf24d1255c6382be774 ]

Add Microchip parts to the Device ID table so the driver supports PCI100x devices.

Add a new macro to quirk the Microchip Switchtec PCI100x parts to allow DMA access via NTB to work when the IOMMU is turned on.

PCI100x family has 6 variants; each variant is designed for different application usages, different port counts and lane counts:

PCI1001 has 1 x4 upstream port and 3 x4 downstream ports PCI1002 has 1 x4 upstream port and 4 x2 downstream ports PCI1003 has 2 x4 upstream ports, 2 x2 upstream ports, and 2 x2 downstream ports PCI1004 has 4 x4 upstream ports PCI1005 has 1 x4 upstream port and 6 x2 downstream ports PCI1006 has 6 x2 upstream ports and 2 x2 downstream ports

[Historical note: these parts use PCI_VENDOR_ID_EFAR (0x1055), from EFAR Microsystems, which was acquired in 1996 by Standard Microsystems Corp, which was acquired by Microchip Technology in 2012. The PCI-SIG confirms that Vendor ID 0x1055 is assigned to Microchip even though it's not visible via https://pcisig.com/membership/member-companies]

Link: https://lore.kernel.org/r/20250120095524.243103-1-Saladi.Rakeshbabu@microchi... Signed-off-by: Rakesh Babu Saladi Saladi.Rakeshbabu@microchip.com [bhelgaas: Vendor ID history] Signed-off-by: Bjorn Helgaas bhelgaas@google.com Acked-By: Logan Gunthorpe logang@deltatee.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/quirks.c | 11 +++++++++++ drivers/pci/switch/switchtec.c | 26 ++++++++++++++++++++++++++ 2 files changed, 37 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index c16c8507d048e..fb115b8ba342d 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -5870,6 +5870,17 @@ SWITCHTEC_QUIRK(0x5552); /* PAXA 52XG5 */ SWITCHTEC_QUIRK(0x5536); /* PAXA 36XG5 */ SWITCHTEC_QUIRK(0x5528); /* PAXA 28XG5 */

+#define SWITCHTEC_PCI100X_QUIRK(vid) \ + DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_EFAR, vid, \ + PCI_CLASS_BRIDGE_OTHER, 8, quirk_switchtec_ntb_dma_alias) +SWITCHTEC_PCI100X_QUIRK(0x1001); /* PCI1001XG4 */ +SWITCHTEC_PCI100X_QUIRK(0x1002); /* PCI1002XG4 */ +SWITCHTEC_PCI100X_QUIRK(0x1003); /* PCI1003XG4 */ +SWITCHTEC_PCI100X_QUIRK(0x1004); /* PCI1004XG4 */ +SWITCHTEC_PCI100X_QUIRK(0x1005); /* PCI1005XG4 */ +SWITCHTEC_PCI100X_QUIRK(0x1006); /* PCI1006XG4 */ + + /* * The PLX NTB uses devfn proxy IDs to move TLPs between NT endpoints. * These IDs are used to forward responses to the originator on the other diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c index 332af6938d7fd..9011518b1d132 100644 --- a/drivers/pci/switch/switchtec.c +++ b/drivers/pci/switch/switchtec.c @@ -1739,6 +1739,26 @@ static void switchtec_pci_remove(struct pci_dev *pdev) .driver_data = gen, \ }

+#define SWITCHTEC_PCI100X_DEVICE(device_id, gen) \ + { \ + .vendor = PCI_VENDOR_ID_EFAR, \ + .device = device_id, \ + .subvendor = PCI_ANY_ID, \ + .subdevice = PCI_ANY_ID, \ + .class = (PCI_CLASS_MEMORY_OTHER << 8), \ + .class_mask = 0xFFFFFFFF, \ + .driver_data = gen, \ + }, \ + { \ + .vendor = PCI_VENDOR_ID_EFAR, \ + .device = device_id, \ + .subvendor = PCI_ANY_ID, \ + .subdevice = PCI_ANY_ID, \ + .class = (PCI_CLASS_BRIDGE_OTHER << 8), \ + .class_mask = 0xFFFFFFFF, \ + .driver_data = gen, \ + } + static const struct pci_device_id switchtec_pci_tbl[] = { SWITCHTEC_PCI_DEVICE(0x8531, SWITCHTEC_GEN3), /* PFX 24xG3 */ SWITCHTEC_PCI_DEVICE(0x8532, SWITCHTEC_GEN3), /* PFX 32xG3 */ @@ -1833,6 +1853,12 @@ static const struct pci_device_id switchtec_pci_tbl[] = { SWITCHTEC_PCI_DEVICE(0x5552, SWITCHTEC_GEN5), /* PAXA 52XG5 */ SWITCHTEC_PCI_DEVICE(0x5536, SWITCHTEC_GEN5), /* PAXA 36XG5 */ SWITCHTEC_PCI_DEVICE(0x5528, SWITCHTEC_GEN5), /* PAXA 28XG5 */ + SWITCHTEC_PCI100X_DEVICE(0x1001, SWITCHTEC_GEN4), /* PCI1001 16XG4 */ + SWITCHTEC_PCI100X_DEVICE(0x1002, SWITCHTEC_GEN4), /* PCI1002 12XG4 */ + SWITCHTEC_PCI100X_DEVICE(0x1003, SWITCHTEC_GEN4), /* PCI1003 16XG4 */ + SWITCHTEC_PCI100X_DEVICE(0x1004, SWITCHTEC_GEN4), /* PCI1004 16XG4 */ + SWITCHTEC_PCI100X_DEVICE(0x1005, SWITCHTEC_GEN4), /* PCI1005 16XG4 */ + SWITCHTEC_PCI100X_DEVICE(0x1006, SWITCHTEC_GEN4), /* PCI1006 16XG4 */ {0} }; MODULE_DEVICE_TABLE(pci, switchtec_pci_tbl);