From: Vivek Gautam <vivek.gautam@codeaurora.org>
To: joro@8bytes.org, robh+dt@kernel.org, robin.murphy@arm.com,
iommu@lists.linux-foundation.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: mark.rutland@arm.com, will.deacon@arm.com, robdclark@gmail.com,
tfiga@chromium.org, sricharan@codeaurora.org,
m.szyprowski@samsung.com, architt@codeaurora.org,
linux-arm-msm@vger.kernel.org, vivek.gautam@codeaurora.org,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH v9 1/5] driver core: Find an existing link between two devices
Date: Tue, 13 Mar 2018 14:25:30 +0530 [thread overview]
Message-ID: <20180313085534.11650-2-vivek.gautam@codeaurora.org> (raw)
In-Reply-To: <20180313085534.11650-1-vivek.gautam@codeaurora.org>
The lists managing the device-links can be traversed to
find the link between two devices. The device_link_add() APIs
does traverse these lists to check if there's already a link
setup between the two devices.
So, add a new APIs, device_link_find(), to find an existing
device link between two devices - suppliers and consumers.
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
* New patch added to this series.
drivers/base/core.c | 30 +++++++++++++++++++++++++++---
include/linux/device.h | 2 ++
2 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 5847364f25d9..e8c9774e4ba2 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -144,6 +144,30 @@ static int device_reorder_to_tail(struct device *dev, void *not_used)
return 0;
}
+/**
+ * device_link_find - find any existing link between two devices.
+ * @consumer: Consumer end of the link.
+ * @supplier: Supplier end of the link.
+ *
+ * Returns pointer to the existing link between a supplier and
+ * and consumer devices, or NULL if no link exists.
+ */
+struct device_link *device_link_find(struct device *consumer,
+ struct device *supplier)
+{
+ struct device_link *link = NULL;
+
+ if (!consumer || !supplier)
+ return NULL;
+
+ list_for_each_entry(link, &supplier->links.consumers, s_node)
+ if (link->consumer == consumer)
+ break;
+
+ return link;
+}
+EXPORT_SYMBOL_GPL(device_link_find);
+
/**
* device_link_add - Create a link between two devices.
* @consumer: Consumer end of the link.
@@ -195,9 +219,9 @@ struct device_link *device_link_add(struct device *consumer,
goto out;
}
- list_for_each_entry(link, &supplier->links.consumers, s_node)
- if (link->consumer == consumer)
- goto out;
+ link = device_link_find(consumer, supplier);
+ if (link)
+ goto out;
link = kzalloc(sizeof(*link), GFP_KERNEL);
if (!link)
diff --git a/include/linux/device.h b/include/linux/device.h
index b093405ed525..13bc1884c3eb 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1278,6 +1278,8 @@ extern const char *dev_driver_string(const struct device *dev);
struct device_link *device_link_add(struct device *consumer,
struct device *supplier, u32 flags);
void device_link_del(struct device_link *link);
+struct device_link *device_link_find(struct device *consumer,
+ struct device *supplier);
#ifdef CONFIG_PRINTK
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
next prev parent reply other threads:[~2018-03-13 8:55 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 8:55 [PATCH v9 0/5] iommu/arm-smmu: Add runtime pm/sleep support Vivek Gautam
2018-03-13 8:55 ` Vivek Gautam [this message]
2018-03-13 9:40 ` [PATCH v9 1/5] driver core: Find an existing link between two devices Rafael J. Wysocki
2018-03-13 9:55 ` Vivek Gautam
2018-03-13 12:49 ` Robin Murphy
2018-03-13 14:39 ` Vivek Gautam
2018-03-13 9:58 ` Vivek Gautam
2018-03-13 10:15 ` Tomasz Figa
2018-03-13 10:34 ` Vivek Gautam
2018-03-13 11:23 ` Tomasz Figa
2018-03-14 11:12 ` Rafael J. Wysocki
2018-03-14 11:50 ` Tomasz Figa
2018-03-14 11:57 ` Rafael J. Wysocki
2018-03-14 12:14 ` Robin Murphy
2018-03-14 12:27 ` Lukas Wunner
2018-03-20 7:56 ` Vivek Gautam
2018-03-14 12:23 ` Lukas Wunner
2018-03-13 8:55 ` [PATCH v9 2/5] iommu/arm-smmu: Add pm_runtime/sleep ops Vivek Gautam
2018-03-13 8:55 ` [PATCH v9 3/5] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Vivek Gautam
2018-03-14 17:46 ` Robin Murphy
2018-03-15 7:17 ` Tomasz Figa
2018-03-20 9:49 ` Vivek Gautam
2018-03-13 8:55 ` [PATCH v9 4/5] iommu/arm-smmu: Add the device_link between masters and smmu Vivek Gautam
2018-03-14 17:50 ` Robin Murphy
2018-03-15 6:18 ` Tomasz Figa
2018-03-15 10:44 ` Robin Murphy
2018-03-15 8:57 ` Vivek Gautam
2018-03-15 11:12 ` Robin Murphy
2018-03-13 8:55 ` [PATCH v9 5/5] iommu/arm-smmu: Add support for qcom,smmu-v2 variant Vivek Gautam
[not found] ` <61d30fff-1bf8-d2c1-bbe9-f93de836ae77@huawei.com>
[not found] ` <7d5af071-ef98-8461-3ce9-e84fc0b3956a@codeaurora.org>
2018-03-28 6:11 ` Yisheng Xie
2018-04-10 13:14 ` Tomasz Figa
2018-04-11 1:22 ` Yisheng Xie
2018-04-11 5:15 ` Vivek Gautam
2018-04-12 1:55 ` Yisheng Xie
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