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Diffstat (limited to 'target/linux/layerscape/patches-5.4/701-net-0136-bus-fsl-mc-add-device-binding-path-driver_override.patch')
-rw-r--r--target/linux/layerscape/patches-5.4/701-net-0136-bus-fsl-mc-add-device-binding-path-driver_override.patch106
1 files changed, 106 insertions, 0 deletions
diff --git a/target/linux/layerscape/patches-5.4/701-net-0136-bus-fsl-mc-add-device-binding-path-driver_override.patch b/target/linux/layerscape/patches-5.4/701-net-0136-bus-fsl-mc-add-device-binding-path-driver_override.patch
new file mode 100644
index 0000000000..23a0e9b361
--- /dev/null
+++ b/target/linux/layerscape/patches-5.4/701-net-0136-bus-fsl-mc-add-device-binding-path-driver_override.patch
@@ -0,0 +1,106 @@
+From f2991d30ff590bf932483a6dfc16c7ebe2f83341 Mon Sep 17 00:00:00 2001
+From: Laurentiu Tudor <laurentiu.tudor@nxp.com>
+Date: Fri, 13 Apr 2018 12:42:40 +0300
+Subject: [PATCH] bus: fsl-mc: add device binding path 'driver_override'
+
+This patch is required for vfio-fsl-mc meta driver to successfully bind
+layerscape container devices for device passthrough. This patch adds
+a mechanism to allow a layerscape device to specify a driver rather than
+a layerscape driver provide a device match.
+
+This patch is based on following proposed patches for PCI and platform
+devices
+- https://lkml.org/lkml/2014/4/8/571 :- For Platform devices
+- http://lists-archives.com/linux-kernel/28030441-pci-introduce-new-device-binding-path-using-pci_dev-driver_override.html
+:- For PCI devices
+
+Example to allow a device (dprc.1) to specifically bind
+with driver (vfio-fsl-mc):-
+ - echo vfio-fsl-mc > /sys/bus/fsl-mc/devices/dprc.1/driver_override
+ - echo dprc.1 > /sys/bus/fsl-mc/drivers/fsl_mc_dprc/unbind
+ - echo dprc.1 > /sys/bus/fsl-mc/drivers/vfio-fsl-mc/bind
+
+Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
+Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
+---
+ drivers/bus/fsl-mc/fsl-mc-bus.c | 53 +++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 53 insertions(+)
+
+--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
++++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
+@@ -83,6 +83,12 @@ static int fsl_mc_bus_match(struct devic
+ struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(drv);
+ bool found = false;
+
++ /* When driver_override is set, only bind to the matching driver */
++ if (mc_dev->driver_override) {
++ found = !strcmp(mc_dev->driver_override, mc_drv->driver.name);
++ goto out;
++ }
++
+ if (!mc_drv->match_id_table)
+ goto out;
+
+@@ -147,8 +153,52 @@ static ssize_t modalias_show(struct devi
+ }
+ static DEVICE_ATTR_RO(modalias);
+
++static ssize_t driver_override_store(struct device *dev,
++ struct device_attribute *attr,
++ const char *buf, size_t count)
++{
++ struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
++ const char *driver_override, *old = mc_dev->driver_override;
++ char *cp;
++
++ if (WARN_ON(dev->bus != &fsl_mc_bus_type))
++ return -EINVAL;
++
++ if (count >= (PAGE_SIZE - 1))
++ return -EINVAL;
++
++ driver_override = kstrndup(buf, count, GFP_KERNEL);
++ if (!driver_override)
++ return -ENOMEM;
++
++ cp = strchr(driver_override, '\n');
++ if (cp)
++ *cp = '\0';
++
++ if (strlen(driver_override)) {
++ mc_dev->driver_override = driver_override;
++ } else {
++ kfree(driver_override);
++ mc_dev->driver_override = NULL;
++ }
++
++ kfree(old);
++
++ return count;
++}
++
++static ssize_t driver_override_show(struct device *dev,
++ struct device_attribute *attr, char *buf)
++{
++ struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
++
++ return snprintf(buf, PAGE_SIZE, "%s\n", mc_dev->driver_override);
++}
++static DEVICE_ATTR_RW(driver_override);
++
+ static struct attribute *fsl_mc_dev_attrs[] = {
+ &dev_attr_modalias.attr,
++ &dev_attr_driver_override.attr,
+ NULL,
+ };
+
+@@ -749,6 +799,9 @@ EXPORT_SYMBOL_GPL(fsl_mc_device_add);
+ */
+ void fsl_mc_device_remove(struct fsl_mc_device *mc_dev)
+ {
++ kfree(mc_dev->driver_override);
++ mc_dev->driver_override = NULL;
++
+ /*
+ * The device-specific remove callback will get invoked by device_del()
+ */