diff options
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.patch | 106 |
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() + */ |