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Message-ID: <5397828.ilPjagaOIa@vostro.rjw.lan>
Date: Mon, 21 Jan 2013 00:23:01 +0100
From: "Rafael J. Wysocki" <rjw@...k.pl>
To: Yinghai Lu <yinghai@...nel.org>
Cc: Bjorn Helgaas <bhelgaas@...gle.com>, Len Brown <lenb@...nel.org>,
Taku Izumi <izumi.taku@...fujitsu.com>,
Jiang Liu <jiang.liu@...wei.com>, linux-pci@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org
Subject: Re: [PATCH v9 11/11] PCI: Put pci dev to device tree as early as possible
On Thursday, January 17, 2013 11:53:22 PM Yinghai Lu wrote:
> We want to put created pci device in the device tree as soon as possible.
> - just after we find it and create pci_dev struct for it.
> so for_pci_dev iteration will not miss them.
>
> But at that time, we can not load driver for them yet. Need to be after
> pci_assign_unsigned_resources() etc to make sure all pci devices get
> resource allocated at first.
>
> Move out device registering out of pci_bus_add_devices, and
> new pci_bus_add_devices() will do the device_attach work to load pci drivers
>
> Signed-off-by: Yinghai Lu <yinghai@...nel.org>
> ---
> drivers/pci/bus.c | 47 +++--------------------------------------------
> drivers/pci/iov.c | 7 -------
> drivers/pci/probe.c | 34 +++++++++++++++++++++++++++-------
> 3 files changed, 30 insertions(+), 58 deletions(-)
>
> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
> index 18c1c6d..0a55845 100644
> --- a/drivers/pci/bus.c
> +++ b/drivers/pci/bus.c
> @@ -178,22 +178,9 @@ static void pci_bus_attach_device(struct pci_dev *dev)
> */
> int pci_bus_add_device(struct pci_dev *dev)
> {
> - int retval;
> -
> - pci_fixup_device(pci_fixup_final, dev);
> -
> - retval = pcibios_add_device(dev);
> - if (retval)
> - return retval;
> -
> - retval = device_add(&dev->dev);
> - if (retval)
> - return retval;
> -
> pci_bus_attach_device(dev);
> dev->is_added = 1;
> - pci_proc_attach_device(dev);
> - pci_create_sysfs_dev_files(dev);
> +
> return 0;
> }
>
> @@ -205,21 +192,9 @@ int pci_bus_add_device(struct pci_dev *dev)
> */
> int pci_bus_add_child(struct pci_bus *bus)
> {
> - int retval;
> -
> - if (bus->bridge)
> - bus->dev.parent = bus->bridge;
> -
> - retval = device_register(&bus->dev);
> - if (retval)
> - return retval;
> -
> bus->is_added = 1;
>
> - /* Create legacy_io and legacy_mem files for this bus */
> - pci_create_legacy_files(bus);
> -
> - return retval;
> + return 0;
> }
Well, what sense does this make to keep that function as is after removing
almost all of the code from it?
>
> /**
> @@ -245,36 +220,20 @@ void pci_bus_add_devices(const struct pci_bus *bus)
> if (dev->is_added)
> continue;
> retval = pci_bus_add_device(dev);
> - if (retval)
> - dev_err(&dev->dev, "Error adding device, continuing\n");
> }
>
> list_for_each_entry(dev, &bus->devices, bus_list) {
> BUG_ON(!dev->is_added);
>
> child = dev->subordinate;
> - /*
> - * If there is an unattached subordinate bus, attach
> - * it and then scan for unattached PCI devices.
> - */
> +
> if (!child)
> continue;
> - if (list_empty(&child->node)) {
> - down_write(&pci_bus_sem);
> - list_add_tail(&child->node, &dev->bus->children);
> - up_write(&pci_bus_sem);
> - }
This doesn't seem to have a replacement. Why isn't it necessary any more?
> pci_bus_add_devices(child);
>
> - /*
> - * register the bus with sysfs as the parent is now
> - * properly registered.
> - */
> if (child->is_added)
> continue;
> retval = pci_bus_add_child(child);
> - if (retval)
> - dev_err(&dev->dev, "Error adding bus, continuing\n");
> }
> }
>
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index bafd2bb..dbad72e 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -48,12 +48,7 @@ static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
> return NULL;
>
> pci_bus_insert_busn_res(child, busnr, busnr);
> - child->dev.parent = bus->bridge;
> rc = pci_bus_add_child(child);
> - if (rc) {
> - pci_remove_bus(child);
> - return NULL;
> - }
>
> return child;
> }
> @@ -123,8 +118,6 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset)
> virtfn->is_virtfn = 1;
>
> rc = pci_bus_add_device(virtfn);
> - if (rc)
> - goto failed1;
> sprintf(buf, "virtfn%u", id);
> rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
> if (rc)
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 9588207..6392dac 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -623,6 +623,7 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
> {
> struct pci_bus *child;
> int i;
> + int ret;
>
> /*
> * Allocate a new bus, and inherit stuff from the parent..
> @@ -637,8 +638,7 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
> child->bus_flags = parent->bus_flags;
>
> /* initialize some portions of the bus device, but don't register it
> - * now as the parent is not properly set up yet. This device will get
> - * registered later in pci_bus_add_devices()
> + * now as the parent is not properly set up yet.
> */
> child->dev.class = &pcibus_class;
> dev_set_name(&child->dev, "%04x:%02x", pci_domain_nr(child), busnr);
> @@ -651,11 +651,14 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
> child->primary = parent->busn_res.start;
> child->busn_res.end = 0xff;
>
> - if (!bridge)
> - return child;
> + if (!bridge) {
> + child->dev.parent = parent->bridge;
> + goto add_dev;
> + }
>
> child->self = bridge;
> child->bridge = get_device(&bridge->dev);
> + child->dev.parent = child->bridge;
> pci_set_bus_of_node(child);
> pci_set_bus_speed(child);
>
> @@ -666,6 +669,13 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
> }
> bridge->subordinate = child;
>
> +add_dev:
> + ret = device_register(&child->dev);
> + WARN_ON(ret < 0);
> +
> + /* Create legacy_io and legacy_mem files for this bus */
> + pci_create_legacy_files(child);
> +
> return child;
> }
>
> @@ -1296,6 +1306,8 @@ static void pci_init_capabilities(struct pci_dev *dev)
>
> void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
> {
> + int ret;
> +
> device_initialize(&dev->dev);
> dev->dev.release = pci_release_dev;
>
> @@ -1326,6 +1338,16 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
> down_write(&pci_bus_sem);
> list_add_tail(&dev->bus_list, &bus->devices);
> up_write(&pci_bus_sem);
> +
> + pci_fixup_device(pci_fixup_final, dev);
> + ret = pcibios_add_device(dev);
> + WARN_ON(ret < 0);
> + /* notifier could use pci capabilities */
> + ret = device_add(&dev->dev);
> + WARN_ON(ret < 0);
> +
> + pci_proc_attach_device(dev);
> + pci_create_sysfs_dev_files(dev);
> }
>
> struct pci_dev *__ref pci_scan_single_device(struct pci_bus *bus, int devfn)
> @@ -1656,13 +1678,13 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
> char bus_addr[64];
> char *fmt;
>
> -
> b = pci_alloc_bus();
> if (!b)
> return NULL;
>
> b->sysdata = sysdata;
> b->ops = ops;
> + b->number = b->busn_res.start = bus;
> b2 = pci_find_bus(pci_domain_nr(b), bus);
> if (b2) {
> /* If we already got to this bus through a different bridge, ignore it */
> @@ -1701,8 +1723,6 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
> /* Create legacy_io and legacy_mem files for this bus */
> pci_create_legacy_files(b);
>
> - b->number = b->busn_res.start = bus;
> -
> if (parent)
> dev_info(parent, "PCI host bridge to bus %s\n", dev_name(&b->dev));
> else
>
Thanks,
Rafael
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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