From 994a65e25df85abc465cfee495557200e8205f9e Mon Sep 17 00:00:00 2001 From: "Keshavamurthy, Anil S" Date: Sun, 21 Oct 2007 16:41:46 -0700 Subject: [PATCH] Intel IOMMU: PCI generic helper function When devices are under a p2p bridge, upstream transactions get replaced by the device id of the bridge as it owns the PCIE transaction. Hence its necessary to setup translations on behalf of the bridge as well. Due to this limitation all devices under a p2p share the same domain in a DMAR. We just cache the type of device, if its a native PCIe device or not for later use. [akpm@linux-foundation.org: BUG_ON -> WARN_ON+recover] Signed-off-by: Anil S Keshavamurthy Cc: Andi Kleen Cc: Peter Zijlstra Cc: Muli Ben-Yehuda Cc: "Siddha, Suresh B" Cc: Arjan van de Ven Cc: Ashok Raj Cc: "David S. Miller" Cc: Christoph Lameter Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/pci/pci.h | 1 + drivers/pci/probe.c | 14 ++++++++++++++ drivers/pci/search.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/pci.h | 2 ++ 4 files changed, 51 insertions(+) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 6fda33de84e..fc87e14b50d 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -90,3 +90,4 @@ pci_match_one_device(const struct pci_device_id *id, const struct pci_dev *dev) return NULL; } +struct pci_dev *pci_find_upstream_pcie_bridge(struct pci_dev *pdev); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 5db6b6690b5..463a5a9d583 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -837,6 +837,19 @@ static void pci_release_dev(struct device *dev) kfree(pci_dev); } +static void set_pcie_port_type(struct pci_dev *pdev) +{ + int pos; + u16 reg16; + + pos = pci_find_capability(pdev, PCI_CAP_ID_EXP); + if (!pos) + return; + pdev->is_pcie = 1; + pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, ®16); + pdev->pcie_type = (reg16 & PCI_EXP_FLAGS_TYPE) >> 4; +} + /** * pci_cfg_space_size - get the configuration space size of the PCI device. * @dev: PCI device @@ -951,6 +964,7 @@ pci_scan_device(struct pci_bus *bus, int devfn) dev->device = (l >> 16) & 0xffff; dev->cfg_size = pci_cfg_space_size(dev); dev->error_state = pci_channel_io_normal; + set_pcie_port_type(dev); /* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer) set this higher, assuming the system even supports it. */ diff --git a/drivers/pci/search.c b/drivers/pci/search.c index c6e79d01ce3..b001b5922e3 100644 --- a/drivers/pci/search.c +++ b/drivers/pci/search.c @@ -14,6 +14,40 @@ #include "pci.h" DECLARE_RWSEM(pci_bus_sem); +/* + * find the upstream PCIE-to-PCI bridge of a PCI device + * if the device is PCIE, return NULL + * if the device isn't connected to a PCIE bridge (that is its parent is a + * legacy PCI bridge and the bridge is directly connected to bus 0), return its + * parent + */ +struct pci_dev * +pci_find_upstream_pcie_bridge(struct pci_dev *pdev) +{ + struct pci_dev *tmp = NULL; + + if (pdev->is_pcie) + return NULL; + while (1) { + if (!pdev->bus->self) + break; + pdev = pdev->bus->self; + /* a p2p bridge */ + if (!pdev->is_pcie) { + tmp = pdev; + continue; + } + /* PCI device should connect to a PCIE bridge */ + if (pdev->pcie_type != PCI_EXP_TYPE_PCI_BRIDGE) { + /* Busted hardware? */ + WARN_ON_ONCE(1); + return NULL; + } + return pdev; + } + + return tmp; +} static struct pci_bus *pci_do_find_bus(struct pci_bus *bus, unsigned char busnr) { diff --git a/include/linux/pci.h b/include/linux/pci.h index 768b93359f9..5d2281f661f 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -141,6 +141,7 @@ struct pci_dev { unsigned int class; /* 3 bytes: (base,sub,prog-if) */ u8 revision; /* PCI revision, low byte of class word */ u8 hdr_type; /* PCI header type (`multi' flag masked out) */ + u8 pcie_type; /* PCI-E device/port type */ u8 rom_base_reg; /* which config register controls the ROM */ u8 pin; /* which interrupt pin this device uses */ @@ -183,6 +184,7 @@ struct pci_dev { unsigned int msi_enabled:1; unsigned int msix_enabled:1; unsigned int is_managed:1; + unsigned int is_pcie:1; atomic_t enable_cnt; /* pci_enable_device has been called */ u32 saved_config_space[16]; /* config space saved at suspend time */ -- 2.20.1