linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Yinghai Lu <yinghai@kernel.org>
To: Bjorn Helgaas <bhelgaas@google.com>,
	Taku Izumi <izumi.taku@jp.fujitsu.com>,
	Jiang Liu <jiang.liu@huawei.com>, x86 <x86@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-acpi@vger.kernel.org, Yinghai Lu <yinghai@kernel.org>,
	Randy Dunlap <rdunlap@xenotime.net>
Subject: [PATCH part3 06/11] PCI, sysfs: Create rescan_bridge under /sys/.../pci/devices/... for pci bridges
Date: Sun,  2 Sep 2012 14:52:16 -0700	[thread overview]
Message-ID: <1346622741-30799-7-git-send-email-yinghai@kernel.org> (raw)
In-Reply-To: <1346622741-30799-1-git-send-email-yinghai@kernel.org>

Current code will create rescan for every pci device under parent bus.
that is not right. The device is already there, there is no reason to rescan it.

We could have rescan for pci bridges. less confusing.

Need to move rescan attr to pci dev bridge attribute group.
And we should rescan bridge's secondary bus instead of primary bus.

-v3: Use device_type for pci dev.
-v4: Seperate pci device type change out
-v5: add rescan_bridge for bridge type, and still keep the old rescan.
	may remove the old rescan later.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 Documentation/ABI/testing/sysfs-bus-pci |   10 ++++++++++
 drivers/pci/pci-sysfs.c                 |   24 ++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 34f5110..95f0f37 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -111,6 +111,16 @@ Description:
 		from this part of the device tree.
 		Depends on CONFIG_HOTPLUG.
 
+What:		/sys/bus/pci/devices/.../rescan_bridge
+Date:		February 2012
+Contact:	Linux PCI developers <linux-pci@vger.kernel.org>
+Description:
+		Writing a non-zero value to this attribute will
+		force a rescan of the bridge and all child buses, and
+		re-discover devices removed earlier from this part of
+		the device tree.
+		Depends on CONFIG_HOTPLUG.
+
 What:		/sys/bus/pci/devices/.../reset
 Date:		July 2009
 Contact:	Michael S. Tsirkin <mst@redhat.com>
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index e37a0e0..2100c04 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -327,6 +327,27 @@ dev_rescan_store(struct device *dev, struct device_attribute *attr,
 	return count;
 }
 
+static ssize_t
+dev_bridge_rescan_store(struct device *dev, struct device_attribute *attr,
+		 const char *buf, size_t count)
+{
+	unsigned long val;
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	if (kstrtoul(buf, 0, &val) < 0)
+		return -EINVAL;
+
+	if (val) {
+		mutex_lock(&pci_remove_rescan_mutex);
+		pci_rescan_bus(pdev->subordinate);
+		mutex_unlock(&pci_remove_rescan_mutex);
+	}
+	return count;
+}
+
+static struct device_attribute pci_dev_bridge_rescan_attr =
+	__ATTR(rescan_bridge, (S_IWUSR|S_IWGRP), NULL, dev_bridge_rescan_store);
+
 static void remove_callback(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
@@ -1371,6 +1392,9 @@ static int __init pci_sysfs_init(void)
 late_initcall(pci_sysfs_init);
 
 static struct attribute *pci_dev_bridge_attrs[] = {
+#ifdef CONFIG_HOTPLUG
+	&pci_dev_bridge_rescan_attr.attr,
+#endif
 	NULL,
 };
 
-- 
1.7.7


  parent reply	other threads:[~2012-09-02 21:52 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-02 21:52 [PATCH part3 00/11] PCI, x86: pci root bus hotplug support - part3 Yinghai Lu
2012-09-02 21:52 ` [PATCH part3 01/11] PCI: Separate out pci_assign_unassigned_bus_resources() Yinghai Lu
2012-09-02 21:52 ` [PATCH part3 02/11] PCI: Move back pci_rescan_bus() to probe.c Yinghai Lu
2012-09-02 21:52 ` [PATCH part3 03/11] PCI: pci_bus_size_bridges() should not size own bridge Yinghai Lu
2012-09-02 21:52 ` [PATCH part3 04/11] PCI: Use __pci_bus_size_bridges() directly in pci_assign_unassigned_bus_resources() Yinghai Lu
2012-09-02 21:52 ` [PATCH part3 05/11] PCI, sysfs: Use device_type and attr_groups with pci dev Yinghai Lu
2012-09-02 21:52 ` Yinghai Lu [this message]
2012-09-02 21:52 ` [PATCH part3 07/11] PCI: Add pci_bus_add_single_device() Yinghai Lu
2012-09-02 21:52 ` [PATCH part3 08/11] PCI: Make pci_rescan_bus_bridge_resize() use pci_scan_bridge Yinghai Lu
2012-09-02 21:52 ` [PATCH part3 09/11] PCI: Clean up rescan_bus_bridge_resize() Yinghai Lu
2012-09-02 21:52 ` [PATCH part3 10/11] PCI: Rescan bus or bridge using callback method too Yinghai Lu
2012-09-02 21:52 ` [PATCH part3 11/11] PCI, sysfs: Clean up rescan/remove with scheule_callback Yinghai Lu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1346622741-30799-7-git-send-email-yinghai@kernel.org \
    --to=yinghai@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=bhelgaas@google.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=izumi.taku@jp.fujitsu.com \
    --cc=jiang.liu@huawei.com \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=rdunlap@xenotime.net \
    --cc=torvalds@linux-foundation.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).