Bjorn
One question, both Upstream and DownStream port is represented by
pci_dev in kernel?
2012/4/26 Bjorn Helgaas <bhelgaas@xxxxxxxxxx>:
> A PCIe downstream port is a P2P bridge. Its secondary interface is
> a link that should lead only to device 0 (unless ARI is enabled)[1], so
> we don't probe for non-zero device numbers.
>
> Some Stratus ftServer systems have a PCIe downstream port (02:00.0) that
> leads to both an upstream port (03:00.0) and a downstream port (03:01.0),
> and 03:01.0 has important devices below it:
>
> [0000:02]-+-00.0-[0000:03]--+-00.0
> \-01.0-[0000:xx]--+-[USB]
> \-[NIC]
>
> Previously, we didn't enumerate device 03:01.0, so USB and the network
> didn't work. This patch adds a DMI quirk to scan all device numbers,
> not just 0, below a downstream port.
>
> Based on a patch by Prarit Bhargava.
>
> [1] PCIe spec r3.0, sec 7.3.1
>
> CC: Myron Stowe <mstowe@xxxxxxxxxx>
> CC: Don Dutile <ddutile@xxxxxxxxxx>
> CC: James Paradis <jim.paradis@xxxxxxxxxxx>
> CC: Matthew Wilcox <matthew.wilcox@xxxxxxxxxxxxxxx>
> CC: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
> CC: Prarit Bhargava <prarit@xxxxxxxxxx>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
> Documentation/kernel-parameters.txt | 3 +++
> arch/x86/pci/common.c | 16 ++++++++++++++++
> drivers/pci/pci.c | 3 +++
> drivers/pci/probe.c | 8 ++++++--
> include/asm-generic/pci-bridge.h | 6 ++++++
> 5 files changed, 34 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index c1601e5..57c3870 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -2161,6 +2161,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> on: Turn realloc on
> realloc same as realloc=on
> noari do not use PCIe ARI.
> + pcie_scan_all Scan all possible PCIE devices. Otherwise we
> + only look for one device below a PCIE downstream
> + port.
>
> pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
> Management.
> diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
> index 323481e..16c5d78 100644
> --- a/arch/x86/pci/common.c
> +++ b/arch/x86/pci/common.c
> @@ -11,6 +11,7 @@
> #include <linux/dmi.h>
> #include <linux/slab.h>
>
> +#include <asm-generic/pci-bridge.h>
> #include <asm/acpi.h>
> #include <asm/segment.h>
> #include <asm/io.h>
> @@ -229,6 +230,14 @@ static int __devinit assign_all_busses(const struct dmi_system_id *d)
> }
> #endif
>
> +static int __devinit set_scan_all(const struct dmi_system_id *d)
> +{
> + printk(KERN_INFO "PCI: %s detected, enabling pci=pcie_scan_all\n",
> + d->ident);
> + pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
> + return 0;
> +}
> +
> static const struct dmi_system_id __devinitconst pciprobe_dmi_table[] = {
> #ifdef __i386__
> /*
> @@ -420,6 +429,13 @@ static const struct dmi_system_id __devinitconst pciprobe_dmi_table[] = {
> DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL585 G2"),
> },
> },
> + {
> + .callback = set_scan_all,
> + .ident = "Stratus/NEC ftServer",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "ftServer"),
> + },
> + },
> {}
> };
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 9e31c0a..8f16900 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -22,6 +22,7 @@
> #include <linux/interrupt.h>
> #include <linux/device.h>
> #include <linux/pm_runtime.h>
> +#include <asm-generic/pci-bridge.h>
> #include <asm/setup.h>
> #include "pci.h"
>
> @@ -3900,6 +3901,8 @@ static int __init pci_setup(char *str)
> pcie_bus_config = PCIE_BUS_PERFORMANCE;
> } else if (!strncmp(str, "pcie_bus_peer2peer", 18)) {
> pcie_bus_config = PCIE_BUS_PEER2PEER;
> + } else if (!strncmp(str, "pcie_scan_all", 13)) {
> + pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
> } else {
> printk(KERN_ERR "PCI: Unknown option `%s'\n",
> str);
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 5e1ca3c..2dc8675 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -10,6 +10,7 @@
> #include <linux/module.h>
> #include <linux/cpumask.h>
> #include <linux/pci-aspm.h>
> +#include <asm-generic/pci-bridge.h>
> #include "pci.h"
>
> #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */
> @@ -1395,10 +1396,13 @@ static unsigned no_next_fn(struct pci_dev *dev, unsigned fn)
> static int only_one_child(struct pci_bus *bus)
> {
> struct pci_dev *parent = bus->self;
> +
> if (!parent || !pci_is_pcie(parent))
> return 0;
> - if (parent->pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
> - parent->pcie_type == PCI_EXP_TYPE_DOWNSTREAM)
> + if (parent->pcie_type == PCI_EXP_TYPE_ROOT_PORT)
> + return 1;
> + if (parent->pcie_type == PCI_EXP_TYPE_DOWNSTREAM &&
> + !pci_has_flag(PCI_SCAN_ALL_PCIE_DEVS))
> return 1;
> return 0;
> }
> diff --git a/include/asm-generic/pci-bridge.h b/include/asm-generic/pci-bridge.h
> index a5b5d5a..20db2e5 100644
> --- a/include/asm-generic/pci-bridge.h
> +++ b/include/asm-generic/pci-bridge.h
> @@ -30,6 +30,12 @@ enum {
> PCI_ENABLE_PROC_DOMAINS = 0x00000010,
> /* ... except for domain 0 */
> PCI_COMPAT_DOMAIN_0 = 0x00000020,
> +
> + /* PCIe downstream ports are bridges that normally lead to only a
> + * device 0, but if this is set, we scan all possible devices, not
> + * just device 0.
> + */
> + PCI_SCAN_ALL_PCIE_DEVS = 0x00000040,
> };
>
> #ifdef CONFIG_PCI
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Richard Yang
Help You, Help Me
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
