Xen project Mailing List

[Xen-devel] [PATCH 2/4 v2] PCI: support ARI capability

To: "Jesse Barnes" <jbarnes@xxxxxxxxxxxxxxxx>, <linux-pci@xxxxxxxxxxxxxxx>

Date: Mon, 1 Sep 2008 19:20:56 +0800

Cc: Randy Dunlap <randy.dunlap@xxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx, Grant Grundler <grundler@xxxxxxxxxxxxxxxx>, kvm@xxxxxxxxxxxxxxx, Matthew Wilcox <matthew@xxxxxx>, Greg KH <greg@xxxxxxxxx>, linux-kernel@xxxxxxxxxxxxxxx, virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx

Delivery-date: Mon, 01 Sep 2008 04:22:25 -0700

List-id: Xen developer discussion <xen-devel.lists.xensource.com>

Thread-index: AckMJM1m9UecPzImTSqDwBr2UDhCDA==

Thread-topic: [PATCH 2/4 v2] PCI: support ARI capability

Support Alternative Routing-ID Interpretation (ARI), which increases the number of functions that can be supported by a PCIe endpoint. ARI is required by SR-IOV. PCI-SIG ARI specification can be found at http://www.pcisig.com/specifications/pciexpress/specifications/ECN-alt-rid-interpretation-070604.pdf Signed-off-by: Yu Zhao <yu.zhao@xxxxxxxxx> Signed-off-by: Eddie Dong <eddie.dong@xxxxxxxxx> --- drivers/pci/Kconfig | 7 ++++ drivers/pci/Makefile | 2 + drivers/pci/ari.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++ drivers/pci/pci.h | 8 +++++ drivers/pci/probe.c | 3 ++ include/linux/pci.h | 25 ++++++++++++++++ include/linux/pci_regs.h | 14 +++++++++ 7 files changed, 130 insertions(+), 0 deletions(-) create mode 100644 drivers/pci/ari.c diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index e1ca425..f43cc46 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -50,3 +50,10 @@ config HT_IRQ This allows native hypertransport devices to use interrupts. If unsure say Y. + +config PCI_ARI + bool "PCI ARI support" + depends on PCI + default n + help + This enables PCI Alternative Routing-ID Interpretation. diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile index 7d63f8c..96f2767 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -53,3 +53,5 @@ obj-$(CONFIG_PCI_SYSCALL) += syscall.o ifeq ($(CONFIG_PCI_DEBUG),y) EXTRA_CFLAGS += -DDEBUG endif + +obj-$(CONFIG_PCI_ARI) += ari.o diff --git a/drivers/pci/ari.c b/drivers/pci/ari.c new file mode 100644 index 0000000..3f1a47a --- /dev/null +++ b/drivers/pci/ari.c @@ -0,0 +1,71 @@ +/* + * drivers/pci/ari.c + * + * Copyright (C) 2008 Intel Corporation, Yu Zhao <yu.zhao@xxxxxxxxx> + * + * PCI Express Alternative Routing-ID Interpretation capability support. + */ + +#include <linux/pci.h> + +#include "pci.h" + +/** + * pci_ari_enable_fwd - enable ARI forwarding + * @dev: the PCI device + */ +void pci_ari_enable_fwd(struct pci_dev *dev) +{ + int pos; + u32 cap; + u16 ctrl; + + if (dev->pcie_type != PCI_EXP_TYPE_ROOT_PORT && + dev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM && + dev->ari_enabled) + return; + + pos = pci_find_capability(dev, PCI_CAP_ID_EXP); + if (!pos) + return; + + pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap); + + if (!(cap & PCI_EXP_DEVCAP2_ARI)) + return; + + dev->ari_enabled = 1; + dev_info(&dev->dev, "ARI forwarding enabled.\n"); + + pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl); + if (ctrl & PCI_EXP_DEVCTL2_ARI) + return; + + ctrl |= PCI_EXP_DEVCTL2_ARI; + pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl); +} + +/** + * pci_ari_next_fn - find next function number + * @dev: the PCI device + * + * Returns function number, or 0 if there are no higher numbered + * functions; returns negative on failure. + */ +int pci_ari_next_fn(struct pci_dev *dev) +{ + int pos; + u16 cap; + + if (dev->pcie_type != PCI_EXP_TYPE_ENDPOINT) + return -EINVAL; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI); + if (!pos) + return -EIO; + + pci_read_config_word(dev, pos + PCI_ARI_CAP, &cap); + + return PCI_ARI_CAP_NFN(cap); +} +EXPORT_SYMBOL_GPL(pci_ari_next_fn); diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 5abd69c..720a607 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -147,3 +147,11 @@ struct pci_slot_attribute { extern int pci_resource_alignment(struct pci_dev *dev, int resno); extern int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); + +#ifdef CONFIG_PCI_ARI +extern void pci_ari_enable_fwd(struct pci_dev *dev); +#else +static inline void pci_ari_enable_fwd(struct pci_dev *dev) +{ +} +#endif /* CONFIG_PCI_ARI */ diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 3994ea3..ad7ad35 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1059,6 +1059,9 @@ int pci_scan_slot(struct pci_bus *bus, int devfn) int func, nr = 0; int scan_all_fns; + if (bus->self) + pci_ari_enable_fwd(bus->self); + scan_all_fns = pcibios_scan_all_fns(bus, devfn); for (func = 0; func < 8; func++, devfn++) { diff --git a/include/linux/pci.h b/include/linux/pci.h index 4b8018f..8ed7405 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -236,6 +236,7 @@ struct pci_dev { unsigned int broken_parity_status:1; /* Device generates false positive parity */ unsigned int msi_enabled:1; unsigned int msix_enabled:1; + unsigned int ari_enabled:1; /* ARI forwarding */ unsigned int is_managed:1; unsigned int is_pcie:1; pci_dev_flags_t dev_flags; @@ -1137,5 +1138,29 @@ static inline void pci_mmcfg_early_init(void) { } static inline void pci_mmcfg_late_init(void) { } #endif +#ifdef CONFIG_PCI_ARI +/** + * pci_ari_fwd_enabled - query ARI forwarding status + * @dev: the PCI device + * + * Returns 1 if ARI forwarding is enabled, or 0 if not enabled; + * returns negative on failure. + */ +static inline int pci_ari_fwd_enabled(struct pci_dev *dev) +{ + return dev->ari_enabled; +} +extern int pci_ari_next_fn(struct pci_dev *dev); +#else +static inline int pci_ari_fwd_enabled(struct pci_dev *dev) +{ + return -EIO; +} +static inline int pci_ari_next_fn(struct pci_dev *dev) +{ + return -EIO; +} +#endif /* CONFIG_PCI_ARI */ + #endif /* __KERNEL__ */ #endif /* LINUX_PCI_H */ diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h index 450684f..eb6686b 100644 --- a/include/linux/pci_regs.h +++ b/include/linux/pci_regs.h @@ -419,6 +419,10 @@ #define PCI_EXP_RTCTL_CRSSVE 0x10 /* CRS Software Visibility Enable */ #define PCI_EXP_RTCAP 30 /* Root Capabilities */ #define PCI_EXP_RTSTA 32 /* Root Status */ +#define PCI_EXP_DEVCAP2 36 /* Device Capabilities 2 */ +#define PCI_EXP_DEVCAP2_ARI 0x20 /* Alternative Routing-ID */ +#define PCI_EXP_DEVCTL2 40 /* Device Control 2 */ +#define PCI_EXP_DEVCTL2_ARI 0x20 /* Alternative Routing-ID */ /* Extended Capabilities (PCI-X 2.0 and Express) */ #define PCI_EXT_CAP_ID(header) (header & 0x0000ffff) @@ -429,6 +433,7 @@ #define PCI_EXT_CAP_ID_VC 2 #define PCI_EXT_CAP_ID_DSN 3 #define PCI_EXT_CAP_ID_PWR 4 +#define PCI_EXT_CAP_ID_ARI 14 /* Advanced Error Reporting */ #define PCI_ERR_UNCOR_STATUS 4 /* Uncorrectable Error Status */ @@ -536,5 +541,14 @@ #define HT_CAPTYPE_GEN3 0xD0 /* Generation 3 hypertransport configuration */ #define HT_CAPTYPE_PM 0xE0 /* Hypertransport powermanagement configuration */ +/* Alternative Routing-ID Interpretation */ +#define PCI_ARI_CAP 0x04 /* ARI Capability Register */ +#define PCI_ARI_CAP_MFVC 0x0001 /* MFVC Function Groups Capability */ +#define PCI_ARI_CAP_ACS 0x0002 /* ACS Function Groups Capability */ +#define PCI_ARI_CAP_NFN(x) (((x) >> 8) & 0xff) /* Next Function Number */ +#define PCI_ARI_CTRL 0x06 /* ARI Control Register */ +#define PCI_ARI_CTRL_MFVC 0x0001 /* MFVC Function Groups Enable */ +#define PCI_ARI_CTRL_ACS 0x0002 /* ACS Function Groups Enable */ +#define PCI_ARI_CTRL_FG(x) (((x) >> 4) & 7) /* Function Group */ #endif /* LINUX_PCI_REGS_H */ -- 1.5.6.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel

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